v4.19.13 snapshot.
diff --git a/drivers/tty/hvc/Kconfig b/drivers/tty/hvc/Kconfig
new file mode 100644
index 0000000..4293c17
--- /dev/null
+++ b/drivers/tty/hvc/Kconfig
@@ -0,0 +1,118 @@
+if TTY
+
+config HVC_DRIVER
+ bool
+ help
+ Generic "hypervisor virtual console" infrastructure for various
+ hypervisors (pSeries, iSeries, Xen).
+ It will automatically be selected if one of the back-end console drivers
+ is selected.
+
+config HVC_IRQ
+ bool
+
+config HVC_CONSOLE
+ bool "pSeries Hypervisor Virtual Console support"
+ depends on PPC_PSERIES
+ select HVC_DRIVER
+ select HVC_IRQ
+ help
+ pSeries machines when partitioned support a hypervisor virtual
+ console. This driver allows each pSeries partition to have a console
+ which is accessed via the HMC.
+
+config HVC_OLD_HVSI
+ bool "Old driver for pSeries serial port (/dev/hvsi*)"
+ depends on HVC_CONSOLE
+ default n
+
+config HVC_OPAL
+ bool "OPAL Console support"
+ depends on PPC_POWERNV
+ select HVC_DRIVER
+ select HVC_IRQ
+ default y
+ help
+ PowerNV machines running under OPAL need that driver to get a console
+
+config HVC_RTAS
+ bool "IBM RTAS Console support"
+ depends on PPC_RTAS
+ select HVC_DRIVER
+ help
+ IBM Console device driver which makes use of RTAS
+
+config HVC_IUCV
+ bool "z/VM IUCV Hypervisor console support (VM only)"
+ depends on S390 && NET
+ select HVC_DRIVER
+ select IUCV
+ default y
+ help
+ This driver provides a Hypervisor console (HVC) back-end to access
+ a Linux (console) terminal via a z/VM IUCV communication path.
+
+config HVC_XEN
+ bool "Xen Hypervisor Console support"
+ depends on XEN
+ select HVC_DRIVER
+ select HVC_IRQ
+ default y
+ help
+ Xen virtual console device driver
+
+config HVC_XEN_FRONTEND
+ bool "Xen Hypervisor Multiple Consoles support"
+ depends on HVC_XEN
+ select XEN_XENBUS_FRONTEND
+ default y
+ help
+ Xen driver for secondary virtual consoles
+
+config HVC_UDBG
+ bool "udbg based fake hypervisor console"
+ depends on PPC
+ select HVC_DRIVER
+ default n
+ help
+ This is meant to be used during HW bring up or debugging when
+ no other console mechanism exist but udbg, to get you a quick
+ console for userspace. Do NOT enable in production kernels.
+
+config HVC_DCC
+ bool "ARM JTAG DCC console"
+ depends on ARM || ARM64
+ select HVC_DRIVER
+ help
+ This console uses the JTAG DCC on ARM to create a console under the HVC
+ driver. This console is used through a JTAG only on ARM. If you don't have
+ a JTAG then you probably don't want this option.
+
+config HVC_RISCV_SBI
+ bool "RISC-V SBI console support"
+ depends on RISCV
+ select HVC_DRIVER
+ help
+ This enables support for console output via RISC-V SBI calls, which
+ is normally used only during boot to output printk.
+
+ If you don't know what do to here, say Y.
+
+config HVCS
+ tristate "IBM Hypervisor Virtual Console Server support"
+ depends on PPC_PSERIES && HVC_CONSOLE
+ help
+ Partitionable IBM Power5 ppc64 machines allow hosting of
+ firmware virtual consoles from one Linux partition by
+ another Linux partition. This driver allows console data
+ from Linux partitions to be accessed through TTY device
+ interfaces in the device tree of a Linux partition running
+ this driver.
+
+ To compile this driver as a module, choose M here: the
+ module will be called hvcs. Additionally, this module
+ will depend on arch specific APIs exported from hvcserver.ko
+ which will also be compiled when this driver is built as a
+ module.
+
+endif # TTY
diff --git a/drivers/tty/hvc/Makefile b/drivers/tty/hvc/Makefile
new file mode 100644
index 0000000..98880e3
--- /dev/null
+++ b/drivers/tty/hvc/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_HVC_CONSOLE) += hvc_vio.o hvsi_lib.o
+obj-$(CONFIG_HVC_OPAL) += hvc_opal.o hvsi_lib.o
+obj-$(CONFIG_HVC_OLD_HVSI) += hvsi.o
+obj-$(CONFIG_HVC_RTAS) += hvc_rtas.o
+obj-$(CONFIG_HVC_DCC) += hvc_dcc.o
+obj-$(CONFIG_HVC_DRIVER) += hvc_console.o
+obj-$(CONFIG_HVC_IRQ) += hvc_irq.o
+obj-$(CONFIG_HVC_XEN) += hvc_xen.o
+obj-$(CONFIG_HVC_IUCV) += hvc_iucv.o
+obj-$(CONFIG_HVC_UDBG) += hvc_udbg.o
+obj-$(CONFIG_HVC_RISCV_SBI) += hvc_riscv_sbi.o
+obj-$(CONFIG_HVCS) += hvcs.o
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
new file mode 100644
index 0000000..27284a2
--- /dev/null
+++ b/drivers/tty/hvc/hvc_console.c
@@ -0,0 +1,1071 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
+ * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
+ * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
+ * Copyright (C) 2004 IBM Corporation
+ *
+ * Additional Author(s):
+ * Ryan S. Arnold <rsa@us.ibm.com>
+ */
+
+#include <linux/console.h>
+#include <linux/cpumask.h>
+#include <linux/init.h>
+#include <linux/kbd_kern.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/list.h>
+#include <linux/major.h>
+#include <linux/atomic.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/freezer.h>
+#include <linux/slab.h>
+#include <linux/serial_core.h>
+
+#include <linux/uaccess.h>
+
+#include "hvc_console.h"
+
+#define HVC_MAJOR 229
+#define HVC_MINOR 0
+
+/*
+ * Wait this long per iteration while trying to push buffered data to the
+ * hypervisor before allowing the tty to complete a close operation.
+ */
+#define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */
+
+/*
+ * These sizes are most efficient for vio, because they are the
+ * native transfer size. We could make them selectable in the
+ * future to better deal with backends that want other buffer sizes.
+ */
+#define N_OUTBUF 16
+#define N_INBUF 16
+
+#define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
+
+static struct tty_driver *hvc_driver;
+static struct task_struct *hvc_task;
+
+/* Picks up late kicks after list walk but before schedule() */
+static int hvc_kicked;
+
+/* hvc_init is triggered from hvc_alloc, i.e. only when actually used */
+static atomic_t hvc_needs_init __read_mostly = ATOMIC_INIT(-1);
+
+static int hvc_init(void);
+
+#ifdef CONFIG_MAGIC_SYSRQ
+static int sysrq_pressed;
+#endif
+
+/* dynamic list of hvc_struct instances */
+static LIST_HEAD(hvc_structs);
+
+/*
+ * Protect the list of hvc_struct instances from inserts and removals during
+ * list traversal.
+ */
+static DEFINE_MUTEX(hvc_structs_mutex);
+
+/*
+ * This value is used to assign a tty->index value to a hvc_struct based
+ * upon order of exposure via hvc_probe(), when we can not match it to
+ * a console candidate registered with hvc_instantiate().
+ */
+static int last_hvc = -1;
+
+/*
+ * Do not call this function with either the hvc_structs_mutex or the hvc_struct
+ * lock held. If successful, this function increments the kref reference
+ * count against the target hvc_struct so it should be released when finished.
+ */
+static struct hvc_struct *hvc_get_by_index(int index)
+{
+ struct hvc_struct *hp;
+ unsigned long flags;
+
+ mutex_lock(&hvc_structs_mutex);
+
+ list_for_each_entry(hp, &hvc_structs, next) {
+ spin_lock_irqsave(&hp->lock, flags);
+ if (hp->index == index) {
+ tty_port_get(&hp->port);
+ spin_unlock_irqrestore(&hp->lock, flags);
+ mutex_unlock(&hvc_structs_mutex);
+ return hp;
+ }
+ spin_unlock_irqrestore(&hp->lock, flags);
+ }
+ hp = NULL;
+ mutex_unlock(&hvc_structs_mutex);
+
+ return hp;
+}
+
+static int __hvc_flush(const struct hv_ops *ops, uint32_t vtermno, bool wait)
+{
+ if (wait)
+ might_sleep();
+
+ if (ops->flush)
+ return ops->flush(vtermno, wait);
+ return 0;
+}
+
+static int hvc_console_flush(const struct hv_ops *ops, uint32_t vtermno)
+{
+ return __hvc_flush(ops, vtermno, false);
+}
+
+/*
+ * Wait for the console to flush before writing more to it. This sleeps.
+ */
+static int hvc_flush(struct hvc_struct *hp)
+{
+ return __hvc_flush(hp->ops, hp->vtermno, true);
+}
+
+/*
+ * Initial console vtermnos for console API usage prior to full console
+ * initialization. Any vty adapter outside this range will not have usable
+ * console interfaces but can still be used as a tty device. This has to be
+ * static because kmalloc will not work during early console init.
+ */
+static const struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES];
+static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] =
+ {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1};
+
+/*
+ * Console APIs, NOT TTY. These APIs are available immediately when
+ * hvc_console_setup() finds adapters.
+ */
+
+static void hvc_console_print(struct console *co, const char *b,
+ unsigned count)
+{
+ char c[N_OUTBUF] __ALIGNED__;
+ unsigned i = 0, n = 0;
+ int r, donecr = 0, index = co->index;
+
+ /* Console access attempt outside of acceptable console range. */
+ if (index >= MAX_NR_HVC_CONSOLES)
+ return;
+
+ /* This console adapter was removed so it is not usable. */
+ if (vtermnos[index] == -1)
+ return;
+
+ while (count > 0 || i > 0) {
+ if (count > 0 && i < sizeof(c)) {
+ if (b[n] == '\n' && !donecr) {
+ c[i++] = '\r';
+ donecr = 1;
+ } else {
+ c[i++] = b[n++];
+ donecr = 0;
+ --count;
+ }
+ } else {
+ r = cons_ops[index]->put_chars(vtermnos[index], c, i);
+ if (r <= 0) {
+ /* throw away characters on error
+ * but spin in case of -EAGAIN */
+ if (r != -EAGAIN) {
+ i = 0;
+ } else {
+ hvc_console_flush(cons_ops[index],
+ vtermnos[index]);
+ }
+ } else if (r > 0) {
+ i -= r;
+ if (i > 0)
+ memmove(c, c+r, i);
+ }
+ }
+ }
+ hvc_console_flush(cons_ops[index], vtermnos[index]);
+}
+
+static struct tty_driver *hvc_console_device(struct console *c, int *index)
+{
+ if (vtermnos[c->index] == -1)
+ return NULL;
+
+ *index = c->index;
+ return hvc_driver;
+}
+
+static int hvc_console_setup(struct console *co, char *options)
+{
+ if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES)
+ return -ENODEV;
+
+ if (vtermnos[co->index] == -1)
+ return -ENODEV;
+
+ return 0;
+}
+
+static struct console hvc_console = {
+ .name = "hvc",
+ .write = hvc_console_print,
+ .device = hvc_console_device,
+ .setup = hvc_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+};
+
+/*
+ * Early console initialization. Precedes driver initialization.
+ *
+ * (1) we are first, and the user specified another driver
+ * -- index will remain -1
+ * (2) we are first and the user specified no driver
+ * -- index will be set to 0, then we will fail setup.
+ * (3) we are first and the user specified our driver
+ * -- index will be set to user specified driver, and we will fail
+ * (4) we are after driver, and this initcall will register us
+ * -- if the user didn't specify a driver then the console will match
+ *
+ * Note that for cases 2 and 3, we will match later when the io driver
+ * calls hvc_instantiate() and call register again.
+ */
+static int __init hvc_console_init(void)
+{
+ register_console(&hvc_console);
+ return 0;
+}
+console_initcall(hvc_console_init);
+
+/* callback when the kboject ref count reaches zero. */
+static void hvc_port_destruct(struct tty_port *port)
+{
+ struct hvc_struct *hp = container_of(port, struct hvc_struct, port);
+ unsigned long flags;
+
+ mutex_lock(&hvc_structs_mutex);
+
+ spin_lock_irqsave(&hp->lock, flags);
+ list_del(&(hp->next));
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ mutex_unlock(&hvc_structs_mutex);
+
+ kfree(hp);
+}
+
+static void hvc_check_console(int index)
+{
+ /* Already enabled, bail out */
+ if (hvc_console.flags & CON_ENABLED)
+ return;
+
+ /* If this index is what the user requested, then register
+ * now (setup won't fail at this point). It's ok to just
+ * call register again if previously .setup failed.
+ */
+ if (index == hvc_console.index)
+ register_console(&hvc_console);
+}
+
+/*
+ * hvc_instantiate() is an early console discovery method which locates
+ * consoles * prior to the vio subsystem discovering them. Hotplugged
+ * vty adapters do NOT get an hvc_instantiate() callback since they
+ * appear after early console init.
+ */
+int hvc_instantiate(uint32_t vtermno, int index, const struct hv_ops *ops)
+{
+ struct hvc_struct *hp;
+
+ if (index < 0 || index >= MAX_NR_HVC_CONSOLES)
+ return -1;
+
+ if (vtermnos[index] != -1)
+ return -1;
+
+ /* make sure no no tty has been registered in this index */
+ hp = hvc_get_by_index(index);
+ if (hp) {
+ tty_port_put(&hp->port);
+ return -1;
+ }
+
+ vtermnos[index] = vtermno;
+ cons_ops[index] = ops;
+
+ /* reserve all indices up to and including this index */
+ if (last_hvc < index)
+ last_hvc = index;
+
+ /* check if we need to re-register the kernel console */
+ hvc_check_console(index);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hvc_instantiate);
+
+/* Wake the sleeping khvcd */
+void hvc_kick(void)
+{
+ hvc_kicked = 1;
+ wake_up_process(hvc_task);
+}
+EXPORT_SYMBOL_GPL(hvc_kick);
+
+static void hvc_unthrottle(struct tty_struct *tty)
+{
+ hvc_kick();
+}
+
+static int hvc_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+ struct hvc_struct *hp;
+ int rc;
+
+ /* Auto increments kref reference if found. */
+ hp = hvc_get_by_index(tty->index);
+ if (!hp)
+ return -ENODEV;
+
+ tty->driver_data = hp;
+
+ rc = tty_port_install(&hp->port, driver, tty);
+ if (rc)
+ tty_port_put(&hp->port);
+ return rc;
+}
+
+/*
+ * The TTY interface won't be used until after the vio layer has exposed the vty
+ * adapter to the kernel.
+ */
+static int hvc_open(struct tty_struct *tty, struct file * filp)
+{
+ struct hvc_struct *hp = tty->driver_data;
+ unsigned long flags;
+ int rc = 0;
+
+ spin_lock_irqsave(&hp->port.lock, flags);
+ /* Check and then increment for fast path open. */
+ if (hp->port.count++ > 0) {
+ spin_unlock_irqrestore(&hp->port.lock, flags);
+ hvc_kick();
+ return 0;
+ } /* else count == 0 */
+ spin_unlock_irqrestore(&hp->port.lock, flags);
+
+ tty_port_tty_set(&hp->port, tty);
+
+ if (hp->ops->notifier_add)
+ rc = hp->ops->notifier_add(hp, hp->data);
+
+ /*
+ * If the notifier fails we return an error. The tty layer
+ * will call hvc_close() after a failed open but we don't want to clean
+ * up there so we'll clean up here and clear out the previously set
+ * tty fields and return the kref reference.
+ */
+ if (rc) {
+ tty_port_tty_set(&hp->port, NULL);
+ tty->driver_data = NULL;
+ tty_port_put(&hp->port);
+ printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc);
+ } else
+ /* We are ready... raise DTR/RTS */
+ if (C_BAUD(tty))
+ if (hp->ops->dtr_rts)
+ hp->ops->dtr_rts(hp, 1);
+
+ /* Force wakeup of the polling thread */
+ hvc_kick();
+
+ return rc;
+}
+
+static void hvc_close(struct tty_struct *tty, struct file * filp)
+{
+ struct hvc_struct *hp;
+ unsigned long flags;
+
+ if (tty_hung_up_p(filp))
+ return;
+
+ /*
+ * No driver_data means that this close was issued after a failed
+ * hvc_open by the tty layer's release_dev() function and we can just
+ * exit cleanly because the kref reference wasn't made.
+ */
+ if (!tty->driver_data)
+ return;
+
+ hp = tty->driver_data;
+
+ spin_lock_irqsave(&hp->port.lock, flags);
+
+ if (--hp->port.count == 0) {
+ spin_unlock_irqrestore(&hp->port.lock, flags);
+ /* We are done with the tty pointer now. */
+ tty_port_tty_set(&hp->port, NULL);
+
+ if (C_HUPCL(tty))
+ if (hp->ops->dtr_rts)
+ hp->ops->dtr_rts(hp, 0);
+
+ if (hp->ops->notifier_del)
+ hp->ops->notifier_del(hp, hp->data);
+
+ /* cancel pending tty resize work */
+ cancel_work_sync(&hp->tty_resize);
+
+ /*
+ * Chain calls chars_in_buffer() and returns immediately if
+ * there is no buffered data otherwise sleeps on a wait queue
+ * waking periodically to check chars_in_buffer().
+ */
+ tty_wait_until_sent(tty, HVC_CLOSE_WAIT);
+ } else {
+ if (hp->port.count < 0)
+ printk(KERN_ERR "hvc_close %X: oops, count is %d\n",
+ hp->vtermno, hp->port.count);
+ spin_unlock_irqrestore(&hp->port.lock, flags);
+ }
+}
+
+static void hvc_cleanup(struct tty_struct *tty)
+{
+ struct hvc_struct *hp = tty->driver_data;
+
+ tty_port_put(&hp->port);
+}
+
+static void hvc_hangup(struct tty_struct *tty)
+{
+ struct hvc_struct *hp = tty->driver_data;
+ unsigned long flags;
+
+ if (!hp)
+ return;
+
+ /* cancel pending tty resize work */
+ cancel_work_sync(&hp->tty_resize);
+
+ spin_lock_irqsave(&hp->port.lock, flags);
+
+ /*
+ * The N_TTY line discipline has problems such that in a close vs
+ * open->hangup case this can be called after the final close so prevent
+ * that from happening for now.
+ */
+ if (hp->port.count <= 0) {
+ spin_unlock_irqrestore(&hp->port.lock, flags);
+ return;
+ }
+
+ hp->port.count = 0;
+ spin_unlock_irqrestore(&hp->port.lock, flags);
+ tty_port_tty_set(&hp->port, NULL);
+
+ hp->n_outbuf = 0;
+
+ if (hp->ops->notifier_hangup)
+ hp->ops->notifier_hangup(hp, hp->data);
+}
+
+/*
+ * Push buffered characters whether they were just recently buffered or waiting
+ * on a blocked hypervisor. Call this function with hp->lock held.
+ */
+static int hvc_push(struct hvc_struct *hp)
+{
+ int n;
+
+ n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf);
+ if (n <= 0) {
+ if (n == 0 || n == -EAGAIN) {
+ hp->do_wakeup = 1;
+ return 0;
+ }
+ /* throw away output on error; this happens when
+ there is no session connected to the vterm. */
+ hp->n_outbuf = 0;
+ } else
+ hp->n_outbuf -= n;
+ if (hp->n_outbuf > 0)
+ memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf);
+ else
+ hp->do_wakeup = 1;
+
+ return n;
+}
+
+static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count)
+{
+ struct hvc_struct *hp = tty->driver_data;
+ unsigned long flags;
+ int rsize, written = 0;
+
+ /* This write was probably executed during a tty close. */
+ if (!hp)
+ return -EPIPE;
+
+ /* FIXME what's this (unprotected) check for? */
+ if (hp->port.count <= 0)
+ return -EIO;
+
+ while (count > 0) {
+ int ret = 0;
+
+ spin_lock_irqsave(&hp->lock, flags);
+
+ rsize = hp->outbuf_size - hp->n_outbuf;
+
+ if (rsize) {
+ if (rsize > count)
+ rsize = count;
+ memcpy(hp->outbuf + hp->n_outbuf, buf, rsize);
+ count -= rsize;
+ buf += rsize;
+ hp->n_outbuf += rsize;
+ written += rsize;
+ }
+
+ if (hp->n_outbuf > 0)
+ ret = hvc_push(hp);
+
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ if (!ret)
+ break;
+
+ if (count) {
+ if (hp->n_outbuf > 0)
+ hvc_flush(hp);
+ cond_resched();
+ }
+ }
+
+ /*
+ * Racy, but harmless, kick thread if there is still pending data.
+ */
+ if (hp->n_outbuf)
+ hvc_kick();
+
+ return written;
+}
+
+/**
+ * hvc_set_winsz() - Resize the hvc tty terminal window.
+ * @work: work structure.
+ *
+ * The routine shall not be called within an atomic context because it
+ * might sleep.
+ *
+ * Locking: hp->lock
+ */
+static void hvc_set_winsz(struct work_struct *work)
+{
+ struct hvc_struct *hp;
+ unsigned long hvc_flags;
+ struct tty_struct *tty;
+ struct winsize ws;
+
+ hp = container_of(work, struct hvc_struct, tty_resize);
+
+ tty = tty_port_tty_get(&hp->port);
+ if (!tty)
+ return;
+
+ spin_lock_irqsave(&hp->lock, hvc_flags);
+ ws = hp->ws;
+ spin_unlock_irqrestore(&hp->lock, hvc_flags);
+
+ tty_do_resize(tty, &ws);
+ tty_kref_put(tty);
+}
+
+/*
+ * This is actually a contract between the driver and the tty layer outlining
+ * how much write room the driver can guarantee will be sent OR BUFFERED. This
+ * driver MUST honor the return value.
+ */
+static int hvc_write_room(struct tty_struct *tty)
+{
+ struct hvc_struct *hp = tty->driver_data;
+
+ if (!hp)
+ return 0;
+
+ return hp->outbuf_size - hp->n_outbuf;
+}
+
+static int hvc_chars_in_buffer(struct tty_struct *tty)
+{
+ struct hvc_struct *hp = tty->driver_data;
+
+ if (!hp)
+ return 0;
+ return hp->n_outbuf;
+}
+
+/*
+ * timeout will vary between the MIN and MAX values defined here. By default
+ * and during console activity we will use a default MIN_TIMEOUT of 10. When
+ * the console is idle, we increase the timeout value on each pass through
+ * msleep until we reach the max. This may be noticeable as a brief (average
+ * one second) delay on the console before the console responds to input when
+ * there has been no input for some time.
+ */
+#define MIN_TIMEOUT (10)
+#define MAX_TIMEOUT (2000)
+static u32 timeout = MIN_TIMEOUT;
+
+/*
+ * Maximum number of bytes to get from the console driver if hvc_poll is
+ * called from driver (and can't sleep). Any more than this and we break
+ * and start polling with khvcd. This value was derived from from an OpenBMC
+ * console with the OPAL driver that results in about 0.25ms interrupts off
+ * latency.
+ */
+#define HVC_ATOMIC_READ_MAX 128
+
+#define HVC_POLL_READ 0x00000001
+#define HVC_POLL_WRITE 0x00000002
+
+static int __hvc_poll(struct hvc_struct *hp, bool may_sleep)
+{
+ struct tty_struct *tty;
+ int i, n, count, poll_mask = 0;
+ char buf[N_INBUF] __ALIGNED__;
+ unsigned long flags;
+ int read_total = 0;
+ int written_total = 0;
+
+ spin_lock_irqsave(&hp->lock, flags);
+
+ /* Push pending writes */
+ if (hp->n_outbuf > 0)
+ written_total = hvc_push(hp);
+
+ /* Reschedule us if still some write pending */
+ if (hp->n_outbuf > 0) {
+ poll_mask |= HVC_POLL_WRITE;
+ /* If hvc_push() was not able to write, sleep a few msecs */
+ timeout = (written_total) ? 0 : MIN_TIMEOUT;
+ }
+
+ if (may_sleep) {
+ spin_unlock_irqrestore(&hp->lock, flags);
+ cond_resched();
+ spin_lock_irqsave(&hp->lock, flags);
+ }
+
+ /* No tty attached, just skip */
+ tty = tty_port_tty_get(&hp->port);
+ if (tty == NULL)
+ goto bail;
+
+ /* Now check if we can get data (are we throttled ?) */
+ if (tty_throttled(tty))
+ goto out;
+
+ /* If we aren't notifier driven and aren't throttled, we always
+ * request a reschedule
+ */
+ if (!hp->irq_requested)
+ poll_mask |= HVC_POLL_READ;
+
+ read_again:
+ /* Read data if any */
+ count = tty_buffer_request_room(&hp->port, N_INBUF);
+
+ /* If flip is full, just reschedule a later read */
+ if (count == 0) {
+ poll_mask |= HVC_POLL_READ;
+ goto out;
+ }
+
+ n = hp->ops->get_chars(hp->vtermno, buf, count);
+ if (n <= 0) {
+ /* Hangup the tty when disconnected from host */
+ if (n == -EPIPE) {
+ spin_unlock_irqrestore(&hp->lock, flags);
+ tty_hangup(tty);
+ spin_lock_irqsave(&hp->lock, flags);
+ } else if ( n == -EAGAIN ) {
+ /*
+ * Some back-ends can only ensure a certain min
+ * num of bytes read, which may be > 'count'.
+ * Let the tty clear the flip buff to make room.
+ */
+ poll_mask |= HVC_POLL_READ;
+ }
+ goto out;
+ }
+
+ for (i = 0; i < n; ++i) {
+#ifdef CONFIG_MAGIC_SYSRQ
+ if (hp->index == hvc_console.index) {
+ /* Handle the SysRq Hack */
+ /* XXX should support a sequence */
+ if (buf[i] == '\x0f') { /* ^O */
+ /* if ^O is pressed again, reset
+ * sysrq_pressed and flip ^O char */
+ sysrq_pressed = !sysrq_pressed;
+ if (sysrq_pressed)
+ continue;
+ } else if (sysrq_pressed) {
+ handle_sysrq(buf[i]);
+ sysrq_pressed = 0;
+ continue;
+ }
+ }
+#endif /* CONFIG_MAGIC_SYSRQ */
+ tty_insert_flip_char(&hp->port, buf[i], 0);
+ }
+ read_total += n;
+
+ if (may_sleep) {
+ /* Keep going until the flip is full */
+ spin_unlock_irqrestore(&hp->lock, flags);
+ cond_resched();
+ spin_lock_irqsave(&hp->lock, flags);
+ goto read_again;
+ } else if (read_total < HVC_ATOMIC_READ_MAX) {
+ /* Break and defer if it's a large read in atomic */
+ goto read_again;
+ }
+
+ /*
+ * Latency break, schedule another poll immediately.
+ */
+ poll_mask |= HVC_POLL_READ;
+
+ out:
+ /* Wakeup write queue if necessary */
+ if (hp->do_wakeup) {
+ hp->do_wakeup = 0;
+ tty_wakeup(tty);
+ }
+ bail:
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ if (read_total) {
+ /* Activity is occurring, so reset the polling backoff value to
+ a minimum for performance. */
+ timeout = MIN_TIMEOUT;
+
+ tty_flip_buffer_push(&hp->port);
+ }
+ tty_kref_put(tty);
+
+ return poll_mask;
+}
+
+int hvc_poll(struct hvc_struct *hp)
+{
+ return __hvc_poll(hp, false);
+}
+EXPORT_SYMBOL_GPL(hvc_poll);
+
+/**
+ * __hvc_resize() - Update terminal window size information.
+ * @hp: HVC console pointer
+ * @ws: Terminal window size structure
+ *
+ * Stores the specified window size information in the hvc structure of @hp.
+ * The function schedule the tty resize update.
+ *
+ * Locking: Locking free; the function MUST be called holding hp->lock
+ */
+void __hvc_resize(struct hvc_struct *hp, struct winsize ws)
+{
+ hp->ws = ws;
+ schedule_work(&hp->tty_resize);
+}
+EXPORT_SYMBOL_GPL(__hvc_resize);
+
+/*
+ * This kthread is either polling or interrupt driven. This is determined by
+ * calling hvc_poll() who determines whether a console adapter support
+ * interrupts.
+ */
+static int khvcd(void *unused)
+{
+ int poll_mask;
+ struct hvc_struct *hp;
+
+ set_freezable();
+ do {
+ poll_mask = 0;
+ hvc_kicked = 0;
+ try_to_freeze();
+ wmb();
+ if (!cpus_are_in_xmon()) {
+ mutex_lock(&hvc_structs_mutex);
+ list_for_each_entry(hp, &hvc_structs, next) {
+ poll_mask |= __hvc_poll(hp, true);
+ cond_resched();
+ }
+ mutex_unlock(&hvc_structs_mutex);
+ } else
+ poll_mask |= HVC_POLL_READ;
+ if (hvc_kicked)
+ continue;
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (!hvc_kicked) {
+ if (poll_mask == 0)
+ schedule();
+ else {
+ unsigned long j_timeout;
+
+ if (timeout < MAX_TIMEOUT)
+ timeout += (timeout >> 6) + 1;
+
+ /*
+ * We don't use msleep_interruptible otherwise
+ * "kick" will fail to wake us up
+ */
+ j_timeout = msecs_to_jiffies(timeout) + 1;
+ schedule_timeout_interruptible(j_timeout);
+ }
+ }
+ __set_current_state(TASK_RUNNING);
+ } while (!kthread_should_stop());
+
+ return 0;
+}
+
+static int hvc_tiocmget(struct tty_struct *tty)
+{
+ struct hvc_struct *hp = tty->driver_data;
+
+ if (!hp || !hp->ops->tiocmget)
+ return -EINVAL;
+ return hp->ops->tiocmget(hp);
+}
+
+static int hvc_tiocmset(struct tty_struct *tty,
+ unsigned int set, unsigned int clear)
+{
+ struct hvc_struct *hp = tty->driver_data;
+
+ if (!hp || !hp->ops->tiocmset)
+ return -EINVAL;
+ return hp->ops->tiocmset(hp, set, clear);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int hvc_poll_init(struct tty_driver *driver, int line, char *options)
+{
+ return 0;
+}
+
+static int hvc_poll_get_char(struct tty_driver *driver, int line)
+{
+ struct tty_struct *tty = driver->ttys[0];
+ struct hvc_struct *hp = tty->driver_data;
+ int n;
+ char ch;
+
+ n = hp->ops->get_chars(hp->vtermno, &ch, 1);
+
+ if (n <= 0)
+ return NO_POLL_CHAR;
+
+ return ch;
+}
+
+static void hvc_poll_put_char(struct tty_driver *driver, int line, char ch)
+{
+ struct tty_struct *tty = driver->ttys[0];
+ struct hvc_struct *hp = tty->driver_data;
+ int n;
+
+ do {
+ n = hp->ops->put_chars(hp->vtermno, &ch, 1);
+ } while (n <= 0);
+}
+#endif
+
+static const struct tty_operations hvc_ops = {
+ .install = hvc_install,
+ .open = hvc_open,
+ .close = hvc_close,
+ .cleanup = hvc_cleanup,
+ .write = hvc_write,
+ .hangup = hvc_hangup,
+ .unthrottle = hvc_unthrottle,
+ .write_room = hvc_write_room,
+ .chars_in_buffer = hvc_chars_in_buffer,
+ .tiocmget = hvc_tiocmget,
+ .tiocmset = hvc_tiocmset,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_init = hvc_poll_init,
+ .poll_get_char = hvc_poll_get_char,
+ .poll_put_char = hvc_poll_put_char,
+#endif
+};
+
+static const struct tty_port_operations hvc_port_ops = {
+ .destruct = hvc_port_destruct,
+};
+
+struct hvc_struct *hvc_alloc(uint32_t vtermno, int data,
+ const struct hv_ops *ops,
+ int outbuf_size)
+{
+ struct hvc_struct *hp;
+ int i;
+
+ /* We wait until a driver actually comes along */
+ if (atomic_inc_not_zero(&hvc_needs_init)) {
+ int err = hvc_init();
+ if (err)
+ return ERR_PTR(err);
+ }
+
+ hp = kzalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size,
+ GFP_KERNEL);
+ if (!hp)
+ return ERR_PTR(-ENOMEM);
+
+ hp->vtermno = vtermno;
+ hp->data = data;
+ hp->ops = ops;
+ hp->outbuf_size = outbuf_size;
+ hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))];
+
+ tty_port_init(&hp->port);
+ hp->port.ops = &hvc_port_ops;
+
+ INIT_WORK(&hp->tty_resize, hvc_set_winsz);
+ spin_lock_init(&hp->lock);
+ mutex_lock(&hvc_structs_mutex);
+
+ /*
+ * find index to use:
+ * see if this vterm id matches one registered for console.
+ */
+ for (i=0; i < MAX_NR_HVC_CONSOLES; i++)
+ if (vtermnos[i] == hp->vtermno &&
+ cons_ops[i] == hp->ops)
+ break;
+
+ /* no matching slot, just use a counter */
+ if (i >= MAX_NR_HVC_CONSOLES)
+ i = ++last_hvc;
+
+ hp->index = i;
+ cons_ops[i] = ops;
+ vtermnos[i] = vtermno;
+
+ list_add_tail(&(hp->next), &hvc_structs);
+ mutex_unlock(&hvc_structs_mutex);
+
+ /* check if we need to re-register the kernel console */
+ hvc_check_console(i);
+
+ return hp;
+}
+EXPORT_SYMBOL_GPL(hvc_alloc);
+
+int hvc_remove(struct hvc_struct *hp)
+{
+ unsigned long flags;
+ struct tty_struct *tty;
+
+ tty = tty_port_tty_get(&hp->port);
+
+ console_lock();
+ spin_lock_irqsave(&hp->lock, flags);
+ if (hp->index < MAX_NR_HVC_CONSOLES) {
+ vtermnos[hp->index] = -1;
+ cons_ops[hp->index] = NULL;
+ }
+
+ /* Don't whack hp->irq because tty_hangup() will need to free the irq. */
+
+ spin_unlock_irqrestore(&hp->lock, flags);
+ console_unlock();
+
+ /*
+ * We 'put' the instance that was grabbed when the kref instance
+ * was initialized using kref_init(). Let the last holder of this
+ * kref cause it to be removed, which will probably be the tty_vhangup
+ * below.
+ */
+ tty_port_put(&hp->port);
+
+ /*
+ * This function call will auto chain call hvc_hangup.
+ */
+ if (tty) {
+ tty_vhangup(tty);
+ tty_kref_put(tty);
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hvc_remove);
+
+/* Driver initialization: called as soon as someone uses hvc_alloc(). */
+static int hvc_init(void)
+{
+ struct tty_driver *drv;
+ int err;
+
+ /* We need more than hvc_count adapters due to hotplug additions. */
+ drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS);
+ if (!drv) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ drv->driver_name = "hvc";
+ drv->name = "hvc";
+ drv->major = HVC_MAJOR;
+ drv->minor_start = HVC_MINOR;
+ drv->type = TTY_DRIVER_TYPE_SYSTEM;
+ drv->init_termios = tty_std_termios;
+ drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS;
+ tty_set_operations(drv, &hvc_ops);
+
+ /* Always start the kthread because there can be hotplug vty adapters
+ * added later. */
+ hvc_task = kthread_run(khvcd, NULL, "khvcd");
+ if (IS_ERR(hvc_task)) {
+ printk(KERN_ERR "Couldn't create kthread for console.\n");
+ err = PTR_ERR(hvc_task);
+ goto put_tty;
+ }
+
+ err = tty_register_driver(drv);
+ if (err) {
+ printk(KERN_ERR "Couldn't register hvc console driver\n");
+ goto stop_thread;
+ }
+
+ /*
+ * Make sure tty is fully registered before allowing it to be
+ * found by hvc_console_device.
+ */
+ smp_mb();
+ hvc_driver = drv;
+ return 0;
+
+stop_thread:
+ kthread_stop(hvc_task);
+ hvc_task = NULL;
+put_tty:
+ put_tty_driver(drv);
+out:
+ return err;
+}
diff --git a/drivers/tty/hvc/hvc_console.h b/drivers/tty/hvc/hvc_console.h
new file mode 100644
index 0000000..e931995
--- /dev/null
+++ b/drivers/tty/hvc/hvc_console.h
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * hvc_console.h
+ * Copyright (C) 2005 IBM Corporation
+ *
+ * Author(s):
+ * Ryan S. Arnold <rsa@us.ibm.com>
+ *
+ * hvc_console header information:
+ * moved here from arch/powerpc/include/asm/hvconsole.h
+ * and drivers/char/hvc_console.c
+ */
+
+#ifndef HVC_CONSOLE_H
+#define HVC_CONSOLE_H
+#include <linux/kref.h>
+#include <linux/tty.h>
+#include <linux/spinlock.h>
+
+/*
+ * This is the max number of console adapters that can/will be found as
+ * console devices on first stage console init. Any number beyond this range
+ * can't be used as a console device but is still a valid tty device.
+ */
+#define MAX_NR_HVC_CONSOLES 16
+
+/*
+ * The Linux TTY code does not support dynamic addition of tty derived devices
+ * so we need to know how many tty devices we might need when space is allocated
+ * for the tty device. Since this driver supports hotplug of vty adapters we
+ * need to make sure we have enough allocated.
+ */
+#define HVC_ALLOC_TTY_ADAPTERS 8
+
+struct hvc_struct {
+ struct tty_port port;
+ spinlock_t lock;
+ int index;
+ int do_wakeup;
+ char *outbuf;
+ int outbuf_size;
+ int n_outbuf;
+ uint32_t vtermno;
+ const struct hv_ops *ops;
+ int irq_requested;
+ int data;
+ struct winsize ws;
+ struct work_struct tty_resize;
+ struct list_head next;
+ unsigned long flags;
+};
+
+/* implemented by a low level driver */
+struct hv_ops {
+ int (*get_chars)(uint32_t vtermno, char *buf, int count);
+ int (*put_chars)(uint32_t vtermno, const char *buf, int count);
+ int (*flush)(uint32_t vtermno, bool wait);
+
+ /* Callbacks for notification. Called in open, close and hangup */
+ int (*notifier_add)(struct hvc_struct *hp, int irq);
+ void (*notifier_del)(struct hvc_struct *hp, int irq);
+ void (*notifier_hangup)(struct hvc_struct *hp, int irq);
+
+ /* tiocmget/set implementation */
+ int (*tiocmget)(struct hvc_struct *hp);
+ int (*tiocmset)(struct hvc_struct *hp, unsigned int set, unsigned int clear);
+
+ /* Callbacks to handle tty ports */
+ void (*dtr_rts)(struct hvc_struct *hp, int raise);
+};
+
+/* Register a vterm and a slot index for use as a console (console_init) */
+extern int hvc_instantiate(uint32_t vtermno, int index,
+ const struct hv_ops *ops);
+
+/* register a vterm for hvc tty operation (module_init or hotplug add) */
+extern struct hvc_struct * hvc_alloc(uint32_t vtermno, int data,
+ const struct hv_ops *ops, int outbuf_size);
+/* remove a vterm from hvc tty operation (module_exit or hotplug remove) */
+extern int hvc_remove(struct hvc_struct *hp);
+
+/* data available */
+int hvc_poll(struct hvc_struct *hp);
+void hvc_kick(void);
+
+/* Resize hvc tty terminal window */
+extern void __hvc_resize(struct hvc_struct *hp, struct winsize ws);
+
+static inline void hvc_resize(struct hvc_struct *hp, struct winsize ws)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&hp->lock, flags);
+ __hvc_resize(hp, ws);
+ spin_unlock_irqrestore(&hp->lock, flags);
+}
+
+/* default notifier for irq based notification */
+extern int notifier_add_irq(struct hvc_struct *hp, int data);
+extern void notifier_del_irq(struct hvc_struct *hp, int data);
+extern void notifier_hangup_irq(struct hvc_struct *hp, int data);
+
+
+#if defined(CONFIG_XMON) && defined(CONFIG_SMP)
+#include <asm/xmon.h>
+#else
+static inline int cpus_are_in_xmon(void)
+{
+ return 0;
+}
+#endif
+
+#endif // HVC_CONSOLE_H
diff --git a/drivers/tty/hvc/hvc_dcc.c b/drivers/tty/hvc/hvc_dcc.c
new file mode 100644
index 0000000..02629a1
--- /dev/null
+++ b/drivers/tty/hvc/hvc_dcc.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2010, 2014 The Linux Foundation. All rights reserved. */
+
+#include <linux/init.h>
+
+#include <asm/dcc.h>
+#include <asm/processor.h>
+
+#include "hvc_console.h"
+
+/* DCC Status Bits */
+#define DCC_STATUS_RX (1 << 30)
+#define DCC_STATUS_TX (1 << 29)
+
+static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++) {
+ while (__dcc_getstatus() & DCC_STATUS_TX)
+ cpu_relax();
+
+ __dcc_putchar(buf[i]);
+ }
+
+ return count;
+}
+
+static int hvc_dcc_get_chars(uint32_t vt, char *buf, int count)
+{
+ int i;
+
+ for (i = 0; i < count; ++i)
+ if (__dcc_getstatus() & DCC_STATUS_RX)
+ buf[i] = __dcc_getchar();
+ else
+ break;
+
+ return i;
+}
+
+static bool hvc_dcc_check(void)
+{
+ unsigned long time = jiffies + (HZ / 10);
+
+ /* Write a test character to check if it is handled */
+ __dcc_putchar('\n');
+
+ while (time_is_after_jiffies(time)) {
+ if (!(__dcc_getstatus() & DCC_STATUS_TX))
+ return true;
+ }
+
+ return false;
+}
+
+static const struct hv_ops hvc_dcc_get_put_ops = {
+ .get_chars = hvc_dcc_get_chars,
+ .put_chars = hvc_dcc_put_chars,
+};
+
+static int __init hvc_dcc_console_init(void)
+{
+ int ret;
+
+ if (!hvc_dcc_check())
+ return -ENODEV;
+
+ /* Returns -1 if error */
+ ret = hvc_instantiate(0, 0, &hvc_dcc_get_put_ops);
+
+ return ret < 0 ? -ENODEV : 0;
+}
+console_initcall(hvc_dcc_console_init);
+
+static int __init hvc_dcc_init(void)
+{
+ struct hvc_struct *p;
+
+ if (!hvc_dcc_check())
+ return -ENODEV;
+
+ p = hvc_alloc(0, 0, &hvc_dcc_get_put_ops, 128);
+
+ return PTR_ERR_OR_ZERO(p);
+}
+device_initcall(hvc_dcc_init);
diff --git a/drivers/tty/hvc/hvc_irq.c b/drivers/tty/hvc/hvc_irq.c
new file mode 100644
index 0000000..4b255df
--- /dev/null
+++ b/drivers/tty/hvc/hvc_irq.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2001,2008
+ *
+ * This file contains the IRQ specific code for hvc_console
+ *
+ */
+
+#include <linux/interrupt.h>
+
+#include "hvc_console.h"
+
+static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance)
+{
+ /* if hvc_poll request a repoll, then kick the hvcd thread */
+ if (hvc_poll(dev_instance))
+ hvc_kick();
+
+ /*
+ * We're safe to always return IRQ_HANDLED as the hvcd thread will
+ * iterate through each hvc_struct.
+ */
+ return IRQ_HANDLED;
+}
+
+/*
+ * For IRQ based systems these callbacks can be used
+ */
+int notifier_add_irq(struct hvc_struct *hp, int irq)
+{
+ int rc;
+
+ if (!irq) {
+ hp->irq_requested = 0;
+ return 0;
+ }
+ rc = request_irq(irq, hvc_handle_interrupt, hp->flags,
+ "hvc_console", hp);
+ if (!rc)
+ hp->irq_requested = 1;
+ return rc;
+}
+
+void notifier_del_irq(struct hvc_struct *hp, int irq)
+{
+ if (!hp->irq_requested)
+ return;
+ free_irq(irq, hp);
+ hp->irq_requested = 0;
+}
+
+void notifier_hangup_irq(struct hvc_struct *hp, int irq)
+{
+ notifier_del_irq(hp, irq);
+}
diff --git a/drivers/tty/hvc/hvc_iucv.c b/drivers/tty/hvc/hvc_iucv.c
new file mode 100644
index 0000000..2af1e57
--- /dev/null
+++ b/drivers/tty/hvc/hvc_iucv.c
@@ -0,0 +1,1479 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * z/VM IUCV hypervisor console (HVC) device driver
+ *
+ * This HVC device driver provides terminal access using
+ * z/VM IUCV communication paths.
+ *
+ * Copyright IBM Corp. 2008, 2013
+ *
+ * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
+ */
+#define KMSG_COMPONENT "hvc_iucv"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <asm/ebcdic.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/mempool.h>
+#include <linux/moduleparam.h>
+#include <linux/tty.h>
+#include <linux/wait.h>
+#include <net/iucv/iucv.h>
+
+#include "hvc_console.h"
+
+
+/* General device driver settings */
+#define HVC_IUCV_MAGIC 0xc9e4c3e5
+#define MAX_HVC_IUCV_LINES HVC_ALLOC_TTY_ADAPTERS
+#define MEMPOOL_MIN_NR (PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4)
+
+/* IUCV TTY message */
+#define MSG_VERSION 0x02 /* Message version */
+#define MSG_TYPE_ERROR 0x01 /* Error message */
+#define MSG_TYPE_TERMENV 0x02 /* Terminal environment variable */
+#define MSG_TYPE_TERMIOS 0x04 /* Terminal IO struct update */
+#define MSG_TYPE_WINSIZE 0x08 /* Terminal window size update */
+#define MSG_TYPE_DATA 0x10 /* Terminal data */
+
+struct iucv_tty_msg {
+ u8 version; /* Message version */
+ u8 type; /* Message type */
+#define MSG_MAX_DATALEN ((u16)(~0))
+ u16 datalen; /* Payload length */
+ u8 data[]; /* Payload buffer */
+} __attribute__((packed));
+#define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data))
+
+enum iucv_state_t {
+ IUCV_DISCONN = 0,
+ IUCV_CONNECTED = 1,
+ IUCV_SEVERED = 2,
+};
+
+enum tty_state_t {
+ TTY_CLOSED = 0,
+ TTY_OPENED = 1,
+};
+
+struct hvc_iucv_private {
+ struct hvc_struct *hvc; /* HVC struct reference */
+ u8 srv_name[8]; /* IUCV service name (ebcdic) */
+ unsigned char is_console; /* Linux console usage flag */
+ enum iucv_state_t iucv_state; /* IUCV connection status */
+ enum tty_state_t tty_state; /* TTY status */
+ struct iucv_path *path; /* IUCV path pointer */
+ spinlock_t lock; /* hvc_iucv_private lock */
+#define SNDBUF_SIZE (PAGE_SIZE) /* must be < MSG_MAX_DATALEN */
+ void *sndbuf; /* send buffer */
+ size_t sndbuf_len; /* length of send buffer */
+#define QUEUE_SNDBUF_DELAY (HZ / 25)
+ struct delayed_work sndbuf_work; /* work: send iucv msg(s) */
+ wait_queue_head_t sndbuf_waitq; /* wait for send completion */
+ struct list_head tty_outqueue; /* outgoing IUCV messages */
+ struct list_head tty_inqueue; /* incoming IUCV messages */
+ struct device *dev; /* device structure */
+ u8 info_path[16]; /* IUCV path info (dev attr) */
+};
+
+struct iucv_tty_buffer {
+ struct list_head list; /* list pointer */
+ struct iucv_message msg; /* store an IUCV message */
+ size_t offset; /* data buffer offset */
+ struct iucv_tty_msg *mbuf; /* buffer to store input/output data */
+};
+
+/* IUCV callback handler */
+static int hvc_iucv_path_pending(struct iucv_path *, u8 *, u8 *);
+static void hvc_iucv_path_severed(struct iucv_path *, u8 *);
+static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *);
+static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *);
+
+
+/* Kernel module parameter: use one terminal device as default */
+static unsigned long hvc_iucv_devices = 1;
+
+/* Array of allocated hvc iucv tty lines... */
+static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES];
+#define IUCV_HVC_CON_IDX (0)
+/* List of z/VM user ID filter entries (struct iucv_vmid_filter) */
+#define MAX_VMID_FILTER (500)
+#define FILTER_WILDCARD_CHAR '*'
+static size_t hvc_iucv_filter_size;
+static void *hvc_iucv_filter;
+static const char *hvc_iucv_filter_string;
+static DEFINE_RWLOCK(hvc_iucv_filter_lock);
+
+/* Kmem cache and mempool for iucv_tty_buffer elements */
+static struct kmem_cache *hvc_iucv_buffer_cache;
+static mempool_t *hvc_iucv_mempool;
+
+/* IUCV handler callback functions */
+static struct iucv_handler hvc_iucv_handler = {
+ .path_pending = hvc_iucv_path_pending,
+ .path_severed = hvc_iucv_path_severed,
+ .message_complete = hvc_iucv_msg_complete,
+ .message_pending = hvc_iucv_msg_pending,
+};
+
+
+/**
+ * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance.
+ * @num: The HVC virtual terminal number (vtermno)
+ *
+ * This function returns the struct hvc_iucv_private instance that corresponds
+ * to the HVC virtual terminal number specified as parameter @num.
+ */
+static struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num)
+{
+ if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices))
+ return NULL;
+ return hvc_iucv_table[num - HVC_IUCV_MAGIC];
+}
+
+/**
+ * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element.
+ * @size: Size of the internal buffer used to store data.
+ * @flags: Memory allocation flags passed to mempool.
+ *
+ * This function allocates a new struct iucv_tty_buffer element and, optionally,
+ * allocates an internal data buffer with the specified size @size.
+ * The internal data buffer is always allocated with GFP_DMA which is
+ * required for receiving and sending data with IUCV.
+ * Note: The total message size arises from the internal buffer size and the
+ * members of the iucv_tty_msg structure.
+ * The function returns NULL if memory allocation has failed.
+ */
+static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags)
+{
+ struct iucv_tty_buffer *bufp;
+
+ bufp = mempool_alloc(hvc_iucv_mempool, flags);
+ if (!bufp)
+ return NULL;
+ memset(bufp, 0, sizeof(*bufp));
+
+ if (size > 0) {
+ bufp->msg.length = MSG_SIZE(size);
+ bufp->mbuf = kmalloc(bufp->msg.length, flags | GFP_DMA);
+ if (!bufp->mbuf) {
+ mempool_free(bufp, hvc_iucv_mempool);
+ return NULL;
+ }
+ bufp->mbuf->version = MSG_VERSION;
+ bufp->mbuf->type = MSG_TYPE_DATA;
+ bufp->mbuf->datalen = (u16) size;
+ }
+ return bufp;
+}
+
+/**
+ * destroy_tty_buffer() - destroy struct iucv_tty_buffer element.
+ * @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL.
+ */
+static void destroy_tty_buffer(struct iucv_tty_buffer *bufp)
+{
+ kfree(bufp->mbuf);
+ mempool_free(bufp, hvc_iucv_mempool);
+}
+
+/**
+ * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element.
+ * @list: List containing struct iucv_tty_buffer elements.
+ */
+static void destroy_tty_buffer_list(struct list_head *list)
+{
+ struct iucv_tty_buffer *ent, *next;
+
+ list_for_each_entry_safe(ent, next, list, list) {
+ list_del(&ent->list);
+ destroy_tty_buffer(ent);
+ }
+}
+
+/**
+ * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer.
+ * @priv: Pointer to struct hvc_iucv_private
+ * @buf: HVC buffer for writing received terminal data.
+ * @count: HVC buffer size.
+ * @has_more_data: Pointer to an int variable.
+ *
+ * The function picks up pending messages from the input queue and receives
+ * the message data that is then written to the specified buffer @buf.
+ * If the buffer size @count is less than the data message size, the
+ * message is kept on the input queue and @has_more_data is set to 1.
+ * If all message data has been written, the message is removed from
+ * the input queue.
+ *
+ * The function returns the number of bytes written to the terminal, zero if
+ * there are no pending data messages available or if there is no established
+ * IUCV path.
+ * If the IUCV path has been severed, then -EPIPE is returned to cause a
+ * hang up (that is issued by the HVC layer).
+ */
+static int hvc_iucv_write(struct hvc_iucv_private *priv,
+ char *buf, int count, int *has_more_data)
+{
+ struct iucv_tty_buffer *rb;
+ int written;
+ int rc;
+
+ /* immediately return if there is no IUCV connection */
+ if (priv->iucv_state == IUCV_DISCONN)
+ return 0;
+
+ /* if the IUCV path has been severed, return -EPIPE to inform the
+ * HVC layer to hang up the tty device. */
+ if (priv->iucv_state == IUCV_SEVERED)
+ return -EPIPE;
+
+ /* check if there are pending messages */
+ if (list_empty(&priv->tty_inqueue))
+ return 0;
+
+ /* receive an iucv message and flip data to the tty (ldisc) */
+ rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list);
+
+ written = 0;
+ if (!rb->mbuf) { /* message not yet received ... */
+ /* allocate mem to store msg data; if no memory is available
+ * then leave the buffer on the list and re-try later */
+ rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC | GFP_DMA);
+ if (!rb->mbuf)
+ return -ENOMEM;
+
+ rc = __iucv_message_receive(priv->path, &rb->msg, 0,
+ rb->mbuf, rb->msg.length, NULL);
+ switch (rc) {
+ case 0: /* Successful */
+ break;
+ case 2: /* No message found */
+ case 9: /* Message purged */
+ break;
+ default:
+ written = -EIO;
+ }
+ /* remove buffer if an error has occurred or received data
+ * is not correct */
+ if (rc || (rb->mbuf->version != MSG_VERSION) ||
+ (rb->msg.length != MSG_SIZE(rb->mbuf->datalen)))
+ goto out_remove_buffer;
+ }
+
+ switch (rb->mbuf->type) {
+ case MSG_TYPE_DATA:
+ written = min_t(int, rb->mbuf->datalen - rb->offset, count);
+ memcpy(buf, rb->mbuf->data + rb->offset, written);
+ if (written < (rb->mbuf->datalen - rb->offset)) {
+ rb->offset += written;
+ *has_more_data = 1;
+ goto out_written;
+ }
+ break;
+
+ case MSG_TYPE_WINSIZE:
+ if (rb->mbuf->datalen != sizeof(struct winsize))
+ break;
+ /* The caller must ensure that the hvc is locked, which
+ * is the case when called from hvc_iucv_get_chars() */
+ __hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data));
+ break;
+
+ case MSG_TYPE_ERROR: /* ignored ... */
+ case MSG_TYPE_TERMENV: /* ignored ... */
+ case MSG_TYPE_TERMIOS: /* ignored ... */
+ break;
+ }
+
+out_remove_buffer:
+ list_del(&rb->list);
+ destroy_tty_buffer(rb);
+ *has_more_data = !list_empty(&priv->tty_inqueue);
+
+out_written:
+ return written;
+}
+
+/**
+ * hvc_iucv_get_chars() - HVC get_chars operation.
+ * @vtermno: HVC virtual terminal number.
+ * @buf: Pointer to a buffer to store data
+ * @count: Size of buffer available for writing
+ *
+ * The HVC thread calls this method to read characters from the back-end.
+ * If an IUCV communication path has been established, pending IUCV messages
+ * are received and data is copied into buffer @buf up to @count bytes.
+ *
+ * Locking: The routine gets called under an irqsave() spinlock; and
+ * the routine locks the struct hvc_iucv_private->lock to call
+ * helper functions.
+ */
+static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count)
+{
+ struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
+ int written;
+ int has_more_data;
+
+ if (count <= 0)
+ return 0;
+
+ if (!priv)
+ return -ENODEV;
+
+ spin_lock(&priv->lock);
+ has_more_data = 0;
+ written = hvc_iucv_write(priv, buf, count, &has_more_data);
+ spin_unlock(&priv->lock);
+
+ /* if there are still messages on the queue... schedule another run */
+ if (has_more_data)
+ hvc_kick();
+
+ return written;
+}
+
+/**
+ * hvc_iucv_queue() - Buffer terminal data for sending.
+ * @priv: Pointer to struct hvc_iucv_private instance.
+ * @buf: Buffer containing data to send.
+ * @count: Size of buffer and amount of data to send.
+ *
+ * The function queues data for sending. To actually send the buffered data,
+ * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY).
+ * The function returns the number of data bytes that has been buffered.
+ *
+ * If the device is not connected, data is ignored and the function returns
+ * @count.
+ * If the buffer is full, the function returns 0.
+ * If an existing IUCV communicaton path has been severed, -EPIPE is returned
+ * (that can be passed to HVC layer to cause a tty hangup).
+ */
+static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf,
+ int count)
+{
+ size_t len;
+
+ if (priv->iucv_state == IUCV_DISCONN)
+ return count; /* ignore data */
+
+ if (priv->iucv_state == IUCV_SEVERED)
+ return -EPIPE;
+
+ len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len);
+ if (!len)
+ return 0;
+
+ memcpy(priv->sndbuf + priv->sndbuf_len, buf, len);
+ priv->sndbuf_len += len;
+
+ if (priv->iucv_state == IUCV_CONNECTED)
+ schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY);
+
+ return len;
+}
+
+/**
+ * hvc_iucv_send() - Send an IUCV message containing terminal data.
+ * @priv: Pointer to struct hvc_iucv_private instance.
+ *
+ * If an IUCV communication path has been established, the buffered output data
+ * is sent via an IUCV message and the number of bytes sent is returned.
+ * Returns 0 if there is no established IUCV communication path or
+ * -EPIPE if an existing IUCV communicaton path has been severed.
+ */
+static int hvc_iucv_send(struct hvc_iucv_private *priv)
+{
+ struct iucv_tty_buffer *sb;
+ int rc, len;
+
+ if (priv->iucv_state == IUCV_SEVERED)
+ return -EPIPE;
+
+ if (priv->iucv_state == IUCV_DISCONN)
+ return -EIO;
+
+ if (!priv->sndbuf_len)
+ return 0;
+
+ /* allocate internal buffer to store msg data and also compute total
+ * message length */
+ sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC);
+ if (!sb)
+ return -ENOMEM;
+
+ memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len);
+ sb->mbuf->datalen = (u16) priv->sndbuf_len;
+ sb->msg.length = MSG_SIZE(sb->mbuf->datalen);
+
+ list_add_tail(&sb->list, &priv->tty_outqueue);
+
+ rc = __iucv_message_send(priv->path, &sb->msg, 0, 0,
+ (void *) sb->mbuf, sb->msg.length);
+ if (rc) {
+ /* drop the message here; however we might want to handle
+ * 0x03 (msg limit reached) by trying again... */
+ list_del(&sb->list);
+ destroy_tty_buffer(sb);
+ }
+ len = priv->sndbuf_len;
+ priv->sndbuf_len = 0;
+
+ return len;
+}
+
+/**
+ * hvc_iucv_sndbuf_work() - Send buffered data over IUCV
+ * @work: Work structure.
+ *
+ * This work queue function sends buffered output data over IUCV and,
+ * if not all buffered data could be sent, reschedules itself.
+ */
+static void hvc_iucv_sndbuf_work(struct work_struct *work)
+{
+ struct hvc_iucv_private *priv;
+
+ priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work);
+ if (!priv)
+ return;
+
+ spin_lock_bh(&priv->lock);
+ hvc_iucv_send(priv);
+ spin_unlock_bh(&priv->lock);
+}
+
+/**
+ * hvc_iucv_put_chars() - HVC put_chars operation.
+ * @vtermno: HVC virtual terminal number.
+ * @buf: Pointer to an buffer to read data from
+ * @count: Size of buffer available for reading
+ *
+ * The HVC thread calls this method to write characters to the back-end.
+ * The function calls hvc_iucv_queue() to queue terminal data for sending.
+ *
+ * Locking: The method gets called under an irqsave() spinlock; and
+ * locks struct hvc_iucv_private->lock.
+ */
+static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+ struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
+ int queued;
+
+ if (count <= 0)
+ return 0;
+
+ if (!priv)
+ return -ENODEV;
+
+ spin_lock(&priv->lock);
+ queued = hvc_iucv_queue(priv, buf, count);
+ spin_unlock(&priv->lock);
+
+ return queued;
+}
+
+/**
+ * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time.
+ * @hp: Pointer to the HVC device (struct hvc_struct)
+ * @id: Additional data (originally passed to hvc_alloc): the index of an struct
+ * hvc_iucv_private instance.
+ *
+ * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private
+ * instance that is derived from @id. Always returns 0.
+ *
+ * Locking: struct hvc_iucv_private->lock, spin_lock_bh
+ */
+static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id)
+{
+ struct hvc_iucv_private *priv;
+
+ priv = hvc_iucv_get_private(id);
+ if (!priv)
+ return 0;
+
+ spin_lock_bh(&priv->lock);
+ priv->tty_state = TTY_OPENED;
+ spin_unlock_bh(&priv->lock);
+
+ return 0;
+}
+
+/**
+ * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance.
+ * @priv: Pointer to the struct hvc_iucv_private instance.
+ */
+static void hvc_iucv_cleanup(struct hvc_iucv_private *priv)
+{
+ destroy_tty_buffer_list(&priv->tty_outqueue);
+ destroy_tty_buffer_list(&priv->tty_inqueue);
+
+ priv->tty_state = TTY_CLOSED;
+ priv->iucv_state = IUCV_DISCONN;
+
+ priv->sndbuf_len = 0;
+}
+
+/**
+ * tty_outqueue_empty() - Test if the tty outq is empty
+ * @priv: Pointer to struct hvc_iucv_private instance.
+ */
+static inline int tty_outqueue_empty(struct hvc_iucv_private *priv)
+{
+ int rc;
+
+ spin_lock_bh(&priv->lock);
+ rc = list_empty(&priv->tty_outqueue);
+ spin_unlock_bh(&priv->lock);
+
+ return rc;
+}
+
+/**
+ * flush_sndbuf_sync() - Flush send buffer and wait for completion
+ * @priv: Pointer to struct hvc_iucv_private instance.
+ *
+ * The routine cancels a pending sndbuf work, calls hvc_iucv_send()
+ * to flush any buffered terminal output data and waits for completion.
+ */
+static void flush_sndbuf_sync(struct hvc_iucv_private *priv)
+{
+ int sync_wait;
+
+ cancel_delayed_work_sync(&priv->sndbuf_work);
+
+ spin_lock_bh(&priv->lock);
+ hvc_iucv_send(priv); /* force sending buffered data */
+ sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */
+ spin_unlock_bh(&priv->lock);
+
+ if (sync_wait)
+ wait_event_timeout(priv->sndbuf_waitq,
+ tty_outqueue_empty(priv), HZ/10);
+}
+
+/**
+ * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up
+ * @priv: Pointer to hvc_iucv_private structure
+ *
+ * This routine severs an existing IUCV communication path and hangs
+ * up the underlying HVC terminal device.
+ * The hang-up occurs only if an IUCV communication path is established;
+ * otherwise there is no need to hang up the terminal device.
+ *
+ * The IUCV HVC hang-up is separated into two steps:
+ * 1. After the IUCV path has been severed, the iucv_state is set to
+ * IUCV_SEVERED.
+ * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the
+ * IUCV_SEVERED state causes the tty hang-up in the HVC layer.
+ *
+ * If the tty has not yet been opened, clean up the hvc_iucv_private
+ * structure to allow re-connects.
+ * If the tty has been opened, let get_chars() return -EPIPE to signal
+ * the HVC layer to hang up the tty and, if so, wake up the HVC thread
+ * to call get_chars()...
+ *
+ * Special notes on hanging up a HVC terminal instantiated as console:
+ * Hang-up: 1. do_tty_hangup() replaces file ops (= hung_up_tty_fops)
+ * 2. do_tty_hangup() calls tty->ops->close() for console_filp
+ * => no hangup notifier is called by HVC (default)
+ * 2. hvc_close() returns because of tty_hung_up_p(filp)
+ * => no delete notifier is called!
+ * Finally, the back-end is not being notified, thus, the tty session is
+ * kept active (TTY_OPEN) to be ready for re-connects.
+ *
+ * Locking: spin_lock(&priv->lock) w/o disabling bh
+ */
+static void hvc_iucv_hangup(struct hvc_iucv_private *priv)
+{
+ struct iucv_path *path;
+
+ path = NULL;
+ spin_lock(&priv->lock);
+ if (priv->iucv_state == IUCV_CONNECTED) {
+ path = priv->path;
+ priv->path = NULL;
+ priv->iucv_state = IUCV_SEVERED;
+ if (priv->tty_state == TTY_CLOSED)
+ hvc_iucv_cleanup(priv);
+ else
+ /* console is special (see above) */
+ if (priv->is_console) {
+ hvc_iucv_cleanup(priv);
+ priv->tty_state = TTY_OPENED;
+ } else
+ hvc_kick();
+ }
+ spin_unlock(&priv->lock);
+
+ /* finally sever path (outside of priv->lock due to lock ordering) */
+ if (path) {
+ iucv_path_sever(path, NULL);
+ iucv_path_free(path);
+ }
+}
+
+/**
+ * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups.
+ * @hp: Pointer to the HVC device (struct hvc_struct)
+ * @id: Additional data (originally passed to hvc_alloc):
+ * the index of an struct hvc_iucv_private instance.
+ *
+ * This routine notifies the HVC back-end that a tty hangup (carrier loss,
+ * virtual or otherwise) has occurred.
+ * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup())
+ * to keep an existing IUCV communication path established.
+ * (Background: vhangup() is called from user space (by getty or login) to
+ * disable writing to the tty by other applications).
+ * If the tty has been opened and an established IUCV path has been severed
+ * (we caused the tty hangup), the function calls hvc_iucv_cleanup().
+ *
+ * Locking: struct hvc_iucv_private->lock
+ */
+static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)
+{
+ struct hvc_iucv_private *priv;
+
+ priv = hvc_iucv_get_private(id);
+ if (!priv)
+ return;
+
+ flush_sndbuf_sync(priv);
+
+ spin_lock_bh(&priv->lock);
+ /* NOTE: If the hangup was scheduled by ourself (from the iucv
+ * path_servered callback [IUCV_SEVERED]), we have to clean up
+ * our structure and to set state to TTY_CLOSED.
+ * If the tty was hung up otherwise (e.g. vhangup()), then we
+ * ignore this hangup and keep an established IUCV path open...
+ * (...the reason is that we are not able to connect back to the
+ * client if we disconnect on hang up) */
+ priv->tty_state = TTY_CLOSED;
+
+ if (priv->iucv_state == IUCV_SEVERED)
+ hvc_iucv_cleanup(priv);
+ spin_unlock_bh(&priv->lock);
+}
+
+/**
+ * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS
+ * @hp: Pointer the HVC device (struct hvc_struct)
+ * @raise: Non-zero to raise or zero to lower DTR/RTS lines
+ *
+ * This routine notifies the HVC back-end to raise or lower DTR/RTS
+ * lines. Raising DTR/RTS is ignored. Lowering DTR/RTS indicates to
+ * drop the IUCV connection (similar to hang up the modem).
+ */
+static void hvc_iucv_dtr_rts(struct hvc_struct *hp, int raise)
+{
+ struct hvc_iucv_private *priv;
+ struct iucv_path *path;
+
+ /* Raising the DTR/RTS is ignored as IUCV connections can be
+ * established at any times.
+ */
+ if (raise)
+ return;
+
+ priv = hvc_iucv_get_private(hp->vtermno);
+ if (!priv)
+ return;
+
+ /* Lowering the DTR/RTS lines disconnects an established IUCV
+ * connection.
+ */
+ flush_sndbuf_sync(priv);
+
+ spin_lock_bh(&priv->lock);
+ path = priv->path; /* save reference to IUCV path */
+ priv->path = NULL;
+ priv->iucv_state = IUCV_DISCONN;
+ spin_unlock_bh(&priv->lock);
+
+ /* Sever IUCV path outside of priv->lock due to lock ordering of:
+ * priv->lock <--> iucv_table_lock */
+ if (path) {
+ iucv_path_sever(path, NULL);
+ iucv_path_free(path);
+ }
+}
+
+/**
+ * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time.
+ * @hp: Pointer to the HVC device (struct hvc_struct)
+ * @id: Additional data (originally passed to hvc_alloc):
+ * the index of an struct hvc_iucv_private instance.
+ *
+ * This routine notifies the HVC back-end that the last tty device fd has been
+ * closed. The function cleans up tty resources. The clean-up of the IUCV
+ * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios
+ * control setting.
+ *
+ * Locking: struct hvc_iucv_private->lock
+ */
+static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
+{
+ struct hvc_iucv_private *priv;
+
+ priv = hvc_iucv_get_private(id);
+ if (!priv)
+ return;
+
+ flush_sndbuf_sync(priv);
+
+ spin_lock_bh(&priv->lock);
+ destroy_tty_buffer_list(&priv->tty_outqueue);
+ destroy_tty_buffer_list(&priv->tty_inqueue);
+ priv->tty_state = TTY_CLOSED;
+ priv->sndbuf_len = 0;
+ spin_unlock_bh(&priv->lock);
+}
+
+/**
+ * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID
+ * @ipvmid: Originating z/VM user ID (right padded with blanks)
+ *
+ * Returns 0 if the z/VM user ID that is specified with @ipvmid is permitted to
+ * connect, otherwise non-zero.
+ */
+static int hvc_iucv_filter_connreq(u8 ipvmid[8])
+{
+ const char *wildcard, *filter_entry;
+ size_t i, len;
+
+ /* Note: default policy is ACCEPT if no filter is set */
+ if (!hvc_iucv_filter_size)
+ return 0;
+
+ for (i = 0; i < hvc_iucv_filter_size; i++) {
+ filter_entry = hvc_iucv_filter + (8 * i);
+
+ /* If a filter entry contains the filter wildcard character,
+ * reduce the length to match the leading portion of the user
+ * ID only (wildcard match). Characters following the wildcard
+ * are ignored.
+ */
+ wildcard = strnchr(filter_entry, 8, FILTER_WILDCARD_CHAR);
+ len = (wildcard) ? wildcard - filter_entry : 8;
+ if (0 == memcmp(ipvmid, filter_entry, len))
+ return 0;
+ }
+ return 1;
+}
+
+/**
+ * hvc_iucv_path_pending() - IUCV handler to process a connection request.
+ * @path: Pending path (struct iucv_path)
+ * @ipvmid: z/VM system identifier of originator
+ * @ipuser: User specified data for this path
+ * (AF_IUCV: port/service name and originator port)
+ *
+ * The function uses the @ipuser data to determine if the pending path belongs
+ * to a terminal managed by this device driver.
+ * If the path belongs to this driver, ensure that the terminal is not accessed
+ * multiple times (only one connection to a terminal is allowed).
+ * If the terminal is not yet connected, the pending path is accepted and is
+ * associated to the appropriate struct hvc_iucv_private instance.
+ *
+ * Returns 0 if @path belongs to a terminal managed by the this device driver;
+ * otherwise returns -ENODEV in order to dispatch this path to other handlers.
+ *
+ * Locking: struct hvc_iucv_private->lock
+ */
+static int hvc_iucv_path_pending(struct iucv_path *path, u8 *ipvmid,
+ u8 *ipuser)
+{
+ struct hvc_iucv_private *priv, *tmp;
+ u8 wildcard[9] = "lnxhvc ";
+ int i, rc, find_unused;
+ u8 nuser_data[16];
+ u8 vm_user_id[9];
+
+ ASCEBC(wildcard, sizeof(wildcard));
+ find_unused = !memcmp(wildcard, ipuser, 8);
+
+ /* First, check if the pending path request is managed by this
+ * IUCV handler:
+ * - find a disconnected device if ipuser contains the wildcard
+ * - find the device that matches the terminal ID in ipuser
+ */
+ priv = NULL;
+ for (i = 0; i < hvc_iucv_devices; i++) {
+ tmp = hvc_iucv_table[i];
+ if (!tmp)
+ continue;
+
+ if (find_unused) {
+ spin_lock(&tmp->lock);
+ if (tmp->iucv_state == IUCV_DISCONN)
+ priv = tmp;
+ spin_unlock(&tmp->lock);
+
+ } else if (!memcmp(tmp->srv_name, ipuser, 8))
+ priv = tmp;
+ if (priv)
+ break;
+ }
+ if (!priv)
+ return -ENODEV;
+
+ /* Enforce that ipvmid is allowed to connect to us */
+ read_lock(&hvc_iucv_filter_lock);
+ rc = hvc_iucv_filter_connreq(ipvmid);
+ read_unlock(&hvc_iucv_filter_lock);
+ if (rc) {
+ iucv_path_sever(path, ipuser);
+ iucv_path_free(path);
+ memcpy(vm_user_id, ipvmid, 8);
+ vm_user_id[8] = 0;
+ pr_info("A connection request from z/VM user ID %s "
+ "was refused\n", vm_user_id);
+ return 0;
+ }
+
+ spin_lock(&priv->lock);
+
+ /* If the terminal is already connected or being severed, then sever
+ * this path to enforce that there is only ONE established communication
+ * path per terminal. */
+ if (priv->iucv_state != IUCV_DISCONN) {
+ iucv_path_sever(path, ipuser);
+ iucv_path_free(path);
+ goto out_path_handled;
+ }
+
+ /* accept path */
+ memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */
+ memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */
+ path->msglim = 0xffff; /* IUCV MSGLIMIT */
+ path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */
+ rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv);
+ if (rc) {
+ iucv_path_sever(path, ipuser);
+ iucv_path_free(path);
+ goto out_path_handled;
+ }
+ priv->path = path;
+ priv->iucv_state = IUCV_CONNECTED;
+
+ /* store path information */
+ memcpy(priv->info_path, ipvmid, 8);
+ memcpy(priv->info_path + 8, ipuser + 8, 8);
+
+ /* flush buffered output data... */
+ schedule_delayed_work(&priv->sndbuf_work, 5);
+
+out_path_handled:
+ spin_unlock(&priv->lock);
+ return 0;
+}
+
+/**
+ * hvc_iucv_path_severed() - IUCV handler to process a path sever.
+ * @path: Pending path (struct iucv_path)
+ * @ipuser: User specified data for this path
+ * (AF_IUCV: port/service name and originator port)
+ *
+ * This function calls the hvc_iucv_hangup() function for the
+ * respective IUCV HVC terminal.
+ *
+ * Locking: struct hvc_iucv_private->lock
+ */
+static void hvc_iucv_path_severed(struct iucv_path *path, u8 *ipuser)
+{
+ struct hvc_iucv_private *priv = path->private;
+
+ hvc_iucv_hangup(priv);
+}
+
+/**
+ * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message.
+ * @path: Pending path (struct iucv_path)
+ * @msg: Pointer to the IUCV message
+ *
+ * The function puts an incoming message on the input queue for later
+ * processing (by hvc_iucv_get_chars() / hvc_iucv_write()).
+ * If the tty has not yet been opened, the message is rejected.
+ *
+ * Locking: struct hvc_iucv_private->lock
+ */
+static void hvc_iucv_msg_pending(struct iucv_path *path,
+ struct iucv_message *msg)
+{
+ struct hvc_iucv_private *priv = path->private;
+ struct iucv_tty_buffer *rb;
+
+ /* reject messages that exceed max size of iucv_tty_msg->datalen */
+ if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) {
+ iucv_message_reject(path, msg);
+ return;
+ }
+
+ spin_lock(&priv->lock);
+
+ /* reject messages if tty has not yet been opened */
+ if (priv->tty_state == TTY_CLOSED) {
+ iucv_message_reject(path, msg);
+ goto unlock_return;
+ }
+
+ /* allocate tty buffer to save iucv msg only */
+ rb = alloc_tty_buffer(0, GFP_ATOMIC);
+ if (!rb) {
+ iucv_message_reject(path, msg);
+ goto unlock_return; /* -ENOMEM */
+ }
+ rb->msg = *msg;
+
+ list_add_tail(&rb->list, &priv->tty_inqueue);
+
+ hvc_kick(); /* wake up hvc thread */
+
+unlock_return:
+ spin_unlock(&priv->lock);
+}
+
+/**
+ * hvc_iucv_msg_complete() - IUCV handler to process message completion
+ * @path: Pending path (struct iucv_path)
+ * @msg: Pointer to the IUCV message
+ *
+ * The function is called upon completion of message delivery to remove the
+ * message from the outqueue. Additional delivery information can be found
+ * msg->audit: rejected messages (0x040000 (IPADRJCT)), and
+ * purged messages (0x010000 (IPADPGNR)).
+ *
+ * Locking: struct hvc_iucv_private->lock
+ */
+static void hvc_iucv_msg_complete(struct iucv_path *path,
+ struct iucv_message *msg)
+{
+ struct hvc_iucv_private *priv = path->private;
+ struct iucv_tty_buffer *ent, *next;
+ LIST_HEAD(list_remove);
+
+ spin_lock(&priv->lock);
+ list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list)
+ if (ent->msg.id == msg->id) {
+ list_move(&ent->list, &list_remove);
+ break;
+ }
+ wake_up(&priv->sndbuf_waitq);
+ spin_unlock(&priv->lock);
+ destroy_tty_buffer_list(&list_remove);
+}
+
+/**
+ * hvc_iucv_pm_freeze() - Freeze PM callback
+ * @dev: IUVC HVC terminal device
+ *
+ * Sever an established IUCV communication path and
+ * trigger a hang-up of the underlying HVC terminal.
+ */
+static int hvc_iucv_pm_freeze(struct device *dev)
+{
+ struct hvc_iucv_private *priv = dev_get_drvdata(dev);
+
+ local_bh_disable();
+ hvc_iucv_hangup(priv);
+ local_bh_enable();
+
+ return 0;
+}
+
+/**
+ * hvc_iucv_pm_restore_thaw() - Thaw and restore PM callback
+ * @dev: IUVC HVC terminal device
+ *
+ * Wake up the HVC thread to trigger hang-up and respective
+ * HVC back-end notifier invocations.
+ */
+static int hvc_iucv_pm_restore_thaw(struct device *dev)
+{
+ hvc_kick();
+ return 0;
+}
+
+static ssize_t hvc_iucv_dev_termid_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct hvc_iucv_private *priv = dev_get_drvdata(dev);
+ size_t len;
+
+ len = sizeof(priv->srv_name);
+ memcpy(buf, priv->srv_name, len);
+ EBCASC(buf, len);
+ buf[len++] = '\n';
+ return len;
+}
+
+static ssize_t hvc_iucv_dev_state_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct hvc_iucv_private *priv = dev_get_drvdata(dev);
+ return sprintf(buf, "%u:%u\n", priv->iucv_state, priv->tty_state);
+}
+
+static ssize_t hvc_iucv_dev_peer_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct hvc_iucv_private *priv = dev_get_drvdata(dev);
+ char vmid[9], ipuser[9];
+
+ memset(vmid, 0, sizeof(vmid));
+ memset(ipuser, 0, sizeof(ipuser));
+
+ spin_lock_bh(&priv->lock);
+ if (priv->iucv_state == IUCV_CONNECTED) {
+ memcpy(vmid, priv->info_path, 8);
+ memcpy(ipuser, priv->info_path + 8, 8);
+ }
+ spin_unlock_bh(&priv->lock);
+ EBCASC(ipuser, 8);
+
+ return sprintf(buf, "%s:%s\n", vmid, ipuser);
+}
+
+
+/* HVC operations */
+static const struct hv_ops hvc_iucv_ops = {
+ .get_chars = hvc_iucv_get_chars,
+ .put_chars = hvc_iucv_put_chars,
+ .notifier_add = hvc_iucv_notifier_add,
+ .notifier_del = hvc_iucv_notifier_del,
+ .notifier_hangup = hvc_iucv_notifier_hangup,
+ .dtr_rts = hvc_iucv_dtr_rts,
+};
+
+/* Suspend / resume device operations */
+static const struct dev_pm_ops hvc_iucv_pm_ops = {
+ .freeze = hvc_iucv_pm_freeze,
+ .thaw = hvc_iucv_pm_restore_thaw,
+ .restore = hvc_iucv_pm_restore_thaw,
+};
+
+/* IUCV HVC device driver */
+static struct device_driver hvc_iucv_driver = {
+ .name = KMSG_COMPONENT,
+ .bus = &iucv_bus,
+ .pm = &hvc_iucv_pm_ops,
+};
+
+/* IUCV HVC device attributes */
+static DEVICE_ATTR(termid, 0640, hvc_iucv_dev_termid_show, NULL);
+static DEVICE_ATTR(state, 0640, hvc_iucv_dev_state_show, NULL);
+static DEVICE_ATTR(peer, 0640, hvc_iucv_dev_peer_show, NULL);
+static struct attribute *hvc_iucv_dev_attrs[] = {
+ &dev_attr_termid.attr,
+ &dev_attr_state.attr,
+ &dev_attr_peer.attr,
+ NULL,
+};
+static struct attribute_group hvc_iucv_dev_attr_group = {
+ .attrs = hvc_iucv_dev_attrs,
+};
+static const struct attribute_group *hvc_iucv_dev_attr_groups[] = {
+ &hvc_iucv_dev_attr_group,
+ NULL,
+};
+
+
+/**
+ * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance
+ * @id: hvc_iucv_table index
+ * @is_console: Flag if the instance is used as Linux console
+ *
+ * This function allocates a new hvc_iucv_private structure and stores
+ * the instance in hvc_iucv_table at index @id.
+ * Returns 0 on success; otherwise non-zero.
+ */
+static int __init hvc_iucv_alloc(int id, unsigned int is_console)
+{
+ struct hvc_iucv_private *priv;
+ char name[9];
+ int rc;
+
+ priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ spin_lock_init(&priv->lock);
+ INIT_LIST_HEAD(&priv->tty_outqueue);
+ INIT_LIST_HEAD(&priv->tty_inqueue);
+ INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work);
+ init_waitqueue_head(&priv->sndbuf_waitq);
+
+ priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL);
+ if (!priv->sndbuf) {
+ kfree(priv);
+ return -ENOMEM;
+ }
+
+ /* set console flag */
+ priv->is_console = is_console;
+
+ /* allocate hvc device */
+ priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */
+ HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256);
+ if (IS_ERR(priv->hvc)) {
+ rc = PTR_ERR(priv->hvc);
+ goto out_error_hvc;
+ }
+
+ /* notify HVC thread instead of using polling */
+ priv->hvc->irq_requested = 1;
+
+ /* setup iucv related information */
+ snprintf(name, 9, "lnxhvc%-2d", id);
+ memcpy(priv->srv_name, name, 8);
+ ASCEBC(priv->srv_name, 8);
+
+ /* create and setup device */
+ priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL);
+ if (!priv->dev) {
+ rc = -ENOMEM;
+ goto out_error_dev;
+ }
+ dev_set_name(priv->dev, "hvc_iucv%d", id);
+ dev_set_drvdata(priv->dev, priv);
+ priv->dev->bus = &iucv_bus;
+ priv->dev->parent = iucv_root;
+ priv->dev->driver = &hvc_iucv_driver;
+ priv->dev->groups = hvc_iucv_dev_attr_groups;
+ priv->dev->release = (void (*)(struct device *)) kfree;
+ rc = device_register(priv->dev);
+ if (rc) {
+ put_device(priv->dev);
+ goto out_error_dev;
+ }
+
+ hvc_iucv_table[id] = priv;
+ return 0;
+
+out_error_dev:
+ hvc_remove(priv->hvc);
+out_error_hvc:
+ free_page((unsigned long) priv->sndbuf);
+ kfree(priv);
+
+ return rc;
+}
+
+/**
+ * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances
+ */
+static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv)
+{
+ hvc_remove(priv->hvc);
+ device_unregister(priv->dev);
+ free_page((unsigned long) priv->sndbuf);
+ kfree(priv);
+}
+
+/**
+ * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID
+ * @filter: String containing a comma-separated list of z/VM user IDs
+ * @dest: Location where to store the parsed z/VM user ID
+ */
+static const char *hvc_iucv_parse_filter(const char *filter, char *dest)
+{
+ const char *nextdelim, *residual;
+ size_t len;
+
+ nextdelim = strchr(filter, ',');
+ if (nextdelim) {
+ len = nextdelim - filter;
+ residual = nextdelim + 1;
+ } else {
+ len = strlen(filter);
+ residual = filter + len;
+ }
+
+ if (len == 0)
+ return ERR_PTR(-EINVAL);
+
+ /* check for '\n' (if called from sysfs) */
+ if (filter[len - 1] == '\n')
+ len--;
+
+ /* prohibit filter entries containing the wildcard character only */
+ if (len == 1 && *filter == FILTER_WILDCARD_CHAR)
+ return ERR_PTR(-EINVAL);
+
+ if (len > 8)
+ return ERR_PTR(-EINVAL);
+
+ /* pad with blanks and save upper case version of user ID */
+ memset(dest, ' ', 8);
+ while (len--)
+ dest[len] = toupper(filter[len]);
+ return residual;
+}
+
+/**
+ * hvc_iucv_setup_filter() - Set up z/VM user ID filter
+ * @filter: String consisting of a comma-separated list of z/VM user IDs
+ *
+ * The function parses the @filter string and creates an array containing
+ * the list of z/VM user ID filter entries.
+ * Return code 0 means success, -EINVAL if the filter is syntactically
+ * incorrect, -ENOMEM if there was not enough memory to allocate the
+ * filter list array, or -ENOSPC if too many z/VM user IDs have been specified.
+ */
+static int hvc_iucv_setup_filter(const char *val)
+{
+ const char *residual;
+ int err;
+ size_t size, count;
+ void *array, *old_filter;
+
+ count = strlen(val);
+ if (count == 0 || (count == 1 && val[0] == '\n')) {
+ size = 0;
+ array = NULL;
+ goto out_replace_filter; /* clear filter */
+ }
+
+ /* count user IDs in order to allocate sufficient memory */
+ size = 1;
+ residual = val;
+ while ((residual = strchr(residual, ',')) != NULL) {
+ residual++;
+ size++;
+ }
+
+ /* check if the specified list exceeds the filter limit */
+ if (size > MAX_VMID_FILTER)
+ return -ENOSPC;
+
+ array = kcalloc(size, 8, GFP_KERNEL);
+ if (!array)
+ return -ENOMEM;
+
+ count = size;
+ residual = val;
+ while (*residual && count) {
+ residual = hvc_iucv_parse_filter(residual,
+ array + ((size - count) * 8));
+ if (IS_ERR(residual)) {
+ err = PTR_ERR(residual);
+ kfree(array);
+ goto out_err;
+ }
+ count--;
+ }
+
+out_replace_filter:
+ write_lock_bh(&hvc_iucv_filter_lock);
+ old_filter = hvc_iucv_filter;
+ hvc_iucv_filter_size = size;
+ hvc_iucv_filter = array;
+ write_unlock_bh(&hvc_iucv_filter_lock);
+ kfree(old_filter);
+
+ err = 0;
+out_err:
+ return err;
+}
+
+/**
+ * param_set_vmidfilter() - Set z/VM user ID filter parameter
+ * @val: String consisting of a comma-separated list of z/VM user IDs
+ * @kp: Kernel parameter pointing to hvc_iucv_filter array
+ *
+ * The function sets up the z/VM user ID filter specified as comma-separated
+ * list of user IDs in @val.
+ * Note: If it is called early in the boot process, @val is stored and
+ * parsed later in hvc_iucv_init().
+ */
+static int param_set_vmidfilter(const char *val, const struct kernel_param *kp)
+{
+ int rc;
+
+ if (!MACHINE_IS_VM || !hvc_iucv_devices)
+ return -ENODEV;
+
+ if (!val)
+ return -EINVAL;
+
+ rc = 0;
+ if (slab_is_available())
+ rc = hvc_iucv_setup_filter(val);
+ else
+ hvc_iucv_filter_string = val; /* defer... */
+ return rc;
+}
+
+/**
+ * param_get_vmidfilter() - Get z/VM user ID filter
+ * @buffer: Buffer to store z/VM user ID filter,
+ * (buffer size assumption PAGE_SIZE)
+ * @kp: Kernel parameter pointing to the hvc_iucv_filter array
+ *
+ * The function stores the filter as a comma-separated list of z/VM user IDs
+ * in @buffer. Typically, sysfs routines call this function for attr show.
+ */
+static int param_get_vmidfilter(char *buffer, const struct kernel_param *kp)
+{
+ int rc;
+ size_t index, len;
+ void *start, *end;
+
+ if (!MACHINE_IS_VM || !hvc_iucv_devices)
+ return -ENODEV;
+
+ rc = 0;
+ read_lock_bh(&hvc_iucv_filter_lock);
+ for (index = 0; index < hvc_iucv_filter_size; index++) {
+ start = hvc_iucv_filter + (8 * index);
+ end = memchr(start, ' ', 8);
+ len = (end) ? end - start : 8;
+ memcpy(buffer + rc, start, len);
+ rc += len;
+ buffer[rc++] = ',';
+ }
+ read_unlock_bh(&hvc_iucv_filter_lock);
+ if (rc)
+ buffer[--rc] = '\0'; /* replace last comma and update rc */
+ return rc;
+}
+
+#define param_check_vmidfilter(name, p) __param_check(name, p, void)
+
+static const struct kernel_param_ops param_ops_vmidfilter = {
+ .set = param_set_vmidfilter,
+ .get = param_get_vmidfilter,
+};
+
+/**
+ * hvc_iucv_init() - z/VM IUCV HVC device driver initialization
+ */
+static int __init hvc_iucv_init(void)
+{
+ int rc;
+ unsigned int i;
+
+ if (!hvc_iucv_devices)
+ return -ENODEV;
+
+ if (!MACHINE_IS_VM) {
+ pr_notice("The z/VM IUCV HVC device driver cannot "
+ "be used without z/VM\n");
+ rc = -ENODEV;
+ goto out_error;
+ }
+
+ if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) {
+ pr_err("%lu is not a valid value for the hvc_iucv= "
+ "kernel parameter\n", hvc_iucv_devices);
+ rc = -EINVAL;
+ goto out_error;
+ }
+
+ /* register IUCV HVC device driver */
+ rc = driver_register(&hvc_iucv_driver);
+ if (rc)
+ goto out_error;
+
+ /* parse hvc_iucv_allow string and create z/VM user ID filter list */
+ if (hvc_iucv_filter_string) {
+ rc = hvc_iucv_setup_filter(hvc_iucv_filter_string);
+ switch (rc) {
+ case 0:
+ break;
+ case -ENOMEM:
+ pr_err("Allocating memory failed with "
+ "reason code=%d\n", 3);
+ goto out_error;
+ case -EINVAL:
+ pr_err("hvc_iucv_allow= does not specify a valid "
+ "z/VM user ID list\n");
+ goto out_error;
+ case -ENOSPC:
+ pr_err("hvc_iucv_allow= specifies too many "
+ "z/VM user IDs\n");
+ goto out_error;
+ default:
+ goto out_error;
+ }
+ }
+
+ hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT,
+ sizeof(struct iucv_tty_buffer),
+ 0, 0, NULL);
+ if (!hvc_iucv_buffer_cache) {
+ pr_err("Allocating memory failed with reason code=%d\n", 1);
+ rc = -ENOMEM;
+ goto out_error;
+ }
+
+ hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR,
+ hvc_iucv_buffer_cache);
+ if (!hvc_iucv_mempool) {
+ pr_err("Allocating memory failed with reason code=%d\n", 2);
+ kmem_cache_destroy(hvc_iucv_buffer_cache);
+ rc = -ENOMEM;
+ goto out_error;
+ }
+
+ /* register the first terminal device as console
+ * (must be done before allocating hvc terminal devices) */
+ rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops);
+ if (rc) {
+ pr_err("Registering HVC terminal device as "
+ "Linux console failed\n");
+ goto out_error_memory;
+ }
+
+ /* allocate hvc_iucv_private structs */
+ for (i = 0; i < hvc_iucv_devices; i++) {
+ rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0);
+ if (rc) {
+ pr_err("Creating a new HVC terminal device "
+ "failed with error code=%d\n", rc);
+ goto out_error_hvc;
+ }
+ }
+
+ /* register IUCV callback handler */
+ rc = iucv_register(&hvc_iucv_handler, 0);
+ if (rc) {
+ pr_err("Registering IUCV handlers failed with error code=%d\n",
+ rc);
+ goto out_error_hvc;
+ }
+
+ return 0;
+
+out_error_hvc:
+ for (i = 0; i < hvc_iucv_devices; i++)
+ if (hvc_iucv_table[i])
+ hvc_iucv_destroy(hvc_iucv_table[i]);
+out_error_memory:
+ mempool_destroy(hvc_iucv_mempool);
+ kmem_cache_destroy(hvc_iucv_buffer_cache);
+out_error:
+ kfree(hvc_iucv_filter);
+ hvc_iucv_devices = 0; /* ensure that we do not provide any device */
+ return rc;
+}
+
+/**
+ * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter
+ * @val: Parameter value (numeric)
+ */
+static int __init hvc_iucv_config(char *val)
+{
+ return kstrtoul(val, 10, &hvc_iucv_devices);
+}
+
+
+device_initcall(hvc_iucv_init);
+__setup("hvc_iucv=", hvc_iucv_config);
+core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640);
diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c
new file mode 100644
index 0000000..77baf89
--- /dev/null
+++ b/drivers/tty/hvc/hvc_opal.c
@@ -0,0 +1,419 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * opal driver interface to hvc_console.c
+ *
+ * Copyright 2011 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
+ */
+
+#undef DEBUG
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/console.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/export.h>
+#include <linux/interrupt.h>
+
+#include <asm/hvconsole.h>
+#include <asm/prom.h>
+#include <asm/firmware.h>
+#include <asm/hvsi.h>
+#include <asm/udbg.h>
+#include <asm/opal.h>
+
+#include "hvc_console.h"
+
+static const char hvc_opal_name[] = "hvc_opal";
+
+static const struct of_device_id hvc_opal_match[] = {
+ { .name = "serial", .compatible = "ibm,opal-console-raw" },
+ { .name = "serial", .compatible = "ibm,opal-console-hvsi" },
+ { },
+};
+
+typedef enum hv_protocol {
+ HV_PROTOCOL_RAW,
+ HV_PROTOCOL_HVSI
+} hv_protocol_t;
+
+struct hvc_opal_priv {
+ hv_protocol_t proto; /* Raw data or HVSI packets */
+ struct hvsi_priv hvsi; /* HVSI specific data */
+};
+static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];
+
+/* For early boot console */
+static struct hvc_opal_priv hvc_opal_boot_priv;
+static u32 hvc_opal_boot_termno;
+
+static const struct hv_ops hvc_opal_raw_ops = {
+ .get_chars = opal_get_chars,
+ .put_chars = opal_put_chars,
+ .flush = opal_flush_chars,
+ .notifier_add = notifier_add_irq,
+ .notifier_del = notifier_del_irq,
+ .notifier_hangup = notifier_hangup_irq,
+};
+
+static int hvc_opal_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
+{
+ struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
+
+ if (WARN_ON(!pv))
+ return -ENODEV;
+
+ return hvsilib_get_chars(&pv->hvsi, buf, count);
+}
+
+static int hvc_opal_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+ struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];
+
+ if (WARN_ON(!pv))
+ return -ENODEV;
+
+ return hvsilib_put_chars(&pv->hvsi, buf, count);
+}
+
+static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
+{
+ struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
+ int rc;
+
+ pr_devel("HVSI@%x: do open !\n", hp->vtermno);
+
+ rc = notifier_add_irq(hp, data);
+ if (rc)
+ return rc;
+
+ return hvsilib_open(&pv->hvsi, hp);
+}
+
+static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
+{
+ struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
+
+ pr_devel("HVSI@%x: do close !\n", hp->vtermno);
+
+ hvsilib_close(&pv->hvsi, hp);
+
+ notifier_del_irq(hp, data);
+}
+
+void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
+{
+ struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
+
+ pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);
+
+ hvsilib_close(&pv->hvsi, hp);
+
+ notifier_hangup_irq(hp, data);
+}
+
+static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
+{
+ struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
+
+ if (!pv)
+ return -EINVAL;
+ return pv->hvsi.mctrl;
+}
+
+static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
+ unsigned int clear)
+{
+ struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
+
+ pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
+ hp->vtermno, set, clear);
+
+ if (set & TIOCM_DTR)
+ hvsilib_write_mctrl(&pv->hvsi, 1);
+ else if (clear & TIOCM_DTR)
+ hvsilib_write_mctrl(&pv->hvsi, 0);
+
+ return 0;
+}
+
+static const struct hv_ops hvc_opal_hvsi_ops = {
+ .get_chars = hvc_opal_hvsi_get_chars,
+ .put_chars = hvc_opal_hvsi_put_chars,
+ .flush = opal_flush_chars,
+ .notifier_add = hvc_opal_hvsi_open,
+ .notifier_del = hvc_opal_hvsi_close,
+ .notifier_hangup = hvc_opal_hvsi_hangup,
+ .tiocmget = hvc_opal_hvsi_tiocmget,
+ .tiocmset = hvc_opal_hvsi_tiocmset,
+};
+
+static int hvc_opal_probe(struct platform_device *dev)
+{
+ const struct hv_ops *ops;
+ struct hvc_struct *hp;
+ struct hvc_opal_priv *pv;
+ hv_protocol_t proto;
+ unsigned int termno, irq, boot = 0;
+ const __be32 *reg;
+
+ if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
+ proto = HV_PROTOCOL_RAW;
+ ops = &hvc_opal_raw_ops;
+ } else if (of_device_is_compatible(dev->dev.of_node,
+ "ibm,opal-console-hvsi")) {
+ proto = HV_PROTOCOL_HVSI;
+ ops = &hvc_opal_hvsi_ops;
+ } else {
+ pr_err("hvc_opal: Unknown protocol for %pOF\n",
+ dev->dev.of_node);
+ return -ENXIO;
+ }
+
+ reg = of_get_property(dev->dev.of_node, "reg", NULL);
+ termno = reg ? be32_to_cpup(reg) : 0;
+
+ /* Is it our boot one ? */
+ if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
+ pv = hvc_opal_privs[termno];
+ boot = 1;
+ } else if (hvc_opal_privs[termno] == NULL) {
+ pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
+ if (!pv)
+ return -ENOMEM;
+ pv->proto = proto;
+ hvc_opal_privs[termno] = pv;
+ if (proto == HV_PROTOCOL_HVSI) {
+ /*
+ * We want put_chars to be atomic to avoid mangling of
+ * hvsi packets.
+ */
+ hvsilib_init(&pv->hvsi,
+ opal_get_chars, opal_put_chars_atomic,
+ termno, 0);
+ }
+
+ /* Instanciate now to establish a mapping index==vtermno */
+ hvc_instantiate(termno, termno, ops);
+ } else {
+ pr_err("hvc_opal: Device %pOF has duplicate terminal number #%d\n",
+ dev->dev.of_node, termno);
+ return -ENXIO;
+ }
+
+ pr_info("hvc%d: %s protocol on %pOF%s\n", termno,
+ proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
+ dev->dev.of_node,
+ boot ? " (boot console)" : "");
+
+ irq = irq_of_parse_and_map(dev->dev.of_node, 0);
+ if (!irq) {
+ pr_info("hvc%d: No interrupts property, using OPAL event\n",
+ termno);
+ irq = opal_event_request(ilog2(OPAL_EVENT_CONSOLE_INPUT));
+ }
+
+ if (!irq) {
+ pr_err("hvc_opal: Unable to map interrupt for device %pOF\n",
+ dev->dev.of_node);
+ return irq;
+ }
+
+ hp = hvc_alloc(termno, irq, ops, MAX_VIO_PUT_CHARS);
+ if (IS_ERR(hp))
+ return PTR_ERR(hp);
+
+ /* hvc consoles on powernv may need to share a single irq */
+ hp->flags = IRQF_SHARED;
+ dev_set_drvdata(&dev->dev, hp);
+
+ return 0;
+}
+
+static int hvc_opal_remove(struct platform_device *dev)
+{
+ struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
+ int rc, termno;
+
+ termno = hp->vtermno;
+ rc = hvc_remove(hp);
+ if (rc == 0) {
+ if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
+ kfree(hvc_opal_privs[termno]);
+ hvc_opal_privs[termno] = NULL;
+ }
+ return rc;
+}
+
+static struct platform_driver hvc_opal_driver = {
+ .probe = hvc_opal_probe,
+ .remove = hvc_opal_remove,
+ .driver = {
+ .name = hvc_opal_name,
+ .of_match_table = hvc_opal_match,
+ }
+};
+
+static int __init hvc_opal_init(void)
+{
+ if (!firmware_has_feature(FW_FEATURE_OPAL))
+ return -ENODEV;
+
+ /* Register as a vio device to receive callbacks */
+ return platform_driver_register(&hvc_opal_driver);
+}
+device_initcall(hvc_opal_init);
+
+static void udbg_opal_putc(char c)
+{
+ unsigned int termno = hvc_opal_boot_termno;
+ int count = -1;
+
+ if (c == '\n')
+ udbg_opal_putc('\r');
+
+ do {
+ switch(hvc_opal_boot_priv.proto) {
+ case HV_PROTOCOL_RAW:
+ count = opal_put_chars(termno, &c, 1);
+ break;
+ case HV_PROTOCOL_HVSI:
+ count = hvc_opal_hvsi_put_chars(termno, &c, 1);
+ break;
+ }
+
+ /* This is needed for the cosole to flush
+ * when there aren't any interrupts.
+ */
+ opal_flush_console(termno);
+ } while(count == 0 || count == -EAGAIN);
+}
+
+static int udbg_opal_getc_poll(void)
+{
+ unsigned int termno = hvc_opal_boot_termno;
+ int rc = 0;
+ char c;
+
+ switch(hvc_opal_boot_priv.proto) {
+ case HV_PROTOCOL_RAW:
+ rc = opal_get_chars(termno, &c, 1);
+ break;
+ case HV_PROTOCOL_HVSI:
+ rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
+ break;
+ }
+ if (!rc)
+ return -1;
+ return c;
+}
+
+static int udbg_opal_getc(void)
+{
+ int ch;
+ for (;;) {
+ ch = udbg_opal_getc_poll();
+ if (ch != -1)
+ return ch;
+ }
+}
+
+static void udbg_init_opal_common(void)
+{
+ udbg_putc = udbg_opal_putc;
+ udbg_getc = udbg_opal_getc;
+ udbg_getc_poll = udbg_opal_getc_poll;
+}
+
+void __init hvc_opal_init_early(void)
+{
+ struct device_node *stdout_node = of_node_get(of_stdout);
+ const __be32 *termno;
+ const struct hv_ops *ops;
+ u32 index;
+
+ /* If the console wasn't in /chosen, try /ibm,opal */
+ if (!stdout_node) {
+ struct device_node *opal, *np;
+
+ /* Current OPAL takeover doesn't provide the stdout
+ * path, so we hard wire it
+ */
+ opal = of_find_node_by_path("/ibm,opal/consoles");
+ if (opal)
+ pr_devel("hvc_opal: Found consoles in new location\n");
+ if (!opal) {
+ opal = of_find_node_by_path("/ibm,opal");
+ if (opal)
+ pr_devel("hvc_opal: "
+ "Found consoles in old location\n");
+ }
+ if (!opal)
+ return;
+ for_each_child_of_node(opal, np) {
+ if (!strcmp(np->name, "serial")) {
+ stdout_node = np;
+ break;
+ }
+ }
+ of_node_put(opal);
+ }
+ if (!stdout_node)
+ return;
+ termno = of_get_property(stdout_node, "reg", NULL);
+ index = termno ? be32_to_cpup(termno) : 0;
+ if (index >= MAX_NR_HVC_CONSOLES)
+ return;
+ hvc_opal_privs[index] = &hvc_opal_boot_priv;
+
+ /* Check the protocol */
+ if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
+ hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
+ ops = &hvc_opal_raw_ops;
+ pr_devel("hvc_opal: Found RAW console\n");
+ }
+ else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
+ hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
+ ops = &hvc_opal_hvsi_ops;
+ hvsilib_init(&hvc_opal_boot_priv.hvsi,
+ opal_get_chars, opal_put_chars_atomic,
+ index, 1);
+ /* HVSI, perform the handshake now */
+ hvsilib_establish(&hvc_opal_boot_priv.hvsi);
+ pr_devel("hvc_opal: Found HVSI console\n");
+ } else
+ goto out;
+ hvc_opal_boot_termno = index;
+ udbg_init_opal_common();
+ add_preferred_console("hvc", index, NULL);
+ hvc_instantiate(index, index, ops);
+out:
+ of_node_put(stdout_node);
+}
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
+void __init udbg_init_debug_opal_raw(void)
+{
+ u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
+ hvc_opal_privs[index] = &hvc_opal_boot_priv;
+ hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
+ hvc_opal_boot_termno = index;
+ udbg_init_opal_common();
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
+void __init udbg_init_debug_opal_hvsi(void)
+{
+ u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
+ hvc_opal_privs[index] = &hvc_opal_boot_priv;
+ hvc_opal_boot_termno = index;
+ udbg_init_opal_common();
+ hvsilib_init(&hvc_opal_boot_priv.hvsi,
+ opal_get_chars, opal_put_chars_atomic,
+ index, 1);
+ hvsilib_establish(&hvc_opal_boot_priv.hvsi);
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */
diff --git a/drivers/tty/hvc/hvc_riscv_sbi.c b/drivers/tty/hvc/hvc_riscv_sbi.c
new file mode 100644
index 0000000..75155bd
--- /dev/null
+++ b/drivers/tty/hvc/hvc_riscv_sbi.c
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2008 David Gibson, IBM Corporation
+ * Copyright (C) 2012 Regents of the University of California
+ * Copyright (C) 2017 SiFive
+ */
+
+#include <linux/console.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+
+#include <asm/sbi.h>
+
+#include "hvc_console.h"
+
+static int hvc_sbi_tty_put(uint32_t vtermno, const char *buf, int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++)
+ sbi_console_putchar(buf[i]);
+
+ return i;
+}
+
+static int hvc_sbi_tty_get(uint32_t vtermno, char *buf, int count)
+{
+ int i, c;
+
+ for (i = 0; i < count; i++) {
+ c = sbi_console_getchar();
+ if (c < 0)
+ break;
+ buf[i] = c;
+ }
+
+ return i;
+}
+
+static const struct hv_ops hvc_sbi_ops = {
+ .get_chars = hvc_sbi_tty_get,
+ .put_chars = hvc_sbi_tty_put,
+};
+
+static int __init hvc_sbi_init(void)
+{
+ return PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_ops, 16));
+}
+device_initcall(hvc_sbi_init);
+
+static int __init hvc_sbi_console_init(void)
+{
+ hvc_instantiate(0, 0, &hvc_sbi_ops);
+ add_preferred_console("hvc", 0, NULL);
+
+ return 0;
+}
+console_initcall(hvc_sbi_console_init);
diff --git a/drivers/tty/hvc/hvc_rtas.c b/drivers/tty/hvc/hvc_rtas.c
new file mode 100644
index 0000000..e8b8c64
--- /dev/null
+++ b/drivers/tty/hvc/hvc_rtas.c
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IBM RTAS driver interface to hvc_console.c
+ *
+ * (C) Copyright IBM Corporation 2001-2005
+ * (C) Copyright Red Hat, Inc. 2005
+ *
+ * Author(s): Maximino Augilar <IBM STI Design Center>
+ * : Ryan S. Arnold <rsa@us.ibm.com>
+ * : Utz Bacher <utz.bacher@de.ibm.com>
+ * : David Woodhouse <dwmw2@infradead.org>
+ *
+ * inspired by drivers/char/hvc_console.c
+ * written by Anton Blanchard and Paul Mackerras
+ */
+
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+
+#include <asm/irq.h>
+#include <asm/rtas.h>
+#include "hvc_console.h"
+
+#define hvc_rtas_cookie 0x67781e15
+struct hvc_struct *hvc_rtas_dev;
+
+static int rtascons_put_char_token = RTAS_UNKNOWN_SERVICE;
+static int rtascons_get_char_token = RTAS_UNKNOWN_SERVICE;
+
+static inline int hvc_rtas_write_console(uint32_t vtermno, const char *buf,
+ int count)
+{
+ int i;
+
+ for (i = 0; i < count; i++) {
+ if (rtas_call(rtascons_put_char_token, 1, 1, NULL, buf[i]))
+ break;
+ }
+
+ return i;
+}
+
+static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count)
+{
+ int i, c;
+
+ for (i = 0; i < count; i++) {
+ if (rtas_call(rtascons_get_char_token, 0, 2, &c))
+ break;
+
+ buf[i] = c;
+ }
+
+ return i;
+}
+
+static const struct hv_ops hvc_rtas_get_put_ops = {
+ .get_chars = hvc_rtas_read_console,
+ .put_chars = hvc_rtas_write_console,
+};
+
+static int __init hvc_rtas_init(void)
+{
+ struct hvc_struct *hp;
+
+ if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
+ rtascons_put_char_token = rtas_token("put-term-char");
+ if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
+ return -EIO;
+
+ if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
+ rtascons_get_char_token = rtas_token("get-term-char");
+ if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
+ return -EIO;
+
+ BUG_ON(hvc_rtas_dev);
+
+ /* Allocate an hvc_struct for the console device we instantiated
+ * earlier. Save off hp so that we can return it on exit */
+ hp = hvc_alloc(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops, 16);
+ if (IS_ERR(hp))
+ return PTR_ERR(hp);
+
+ hvc_rtas_dev = hp;
+
+ return 0;
+}
+device_initcall(hvc_rtas_init);
+
+/* This will happen prior to module init. There is no tty at this time? */
+static int __init hvc_rtas_console_init(void)
+{
+ rtascons_put_char_token = rtas_token("put-term-char");
+ if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
+ return -EIO;
+
+ rtascons_get_char_token = rtas_token("get-term-char");
+ if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
+ return -EIO;
+
+ hvc_instantiate(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops);
+ add_preferred_console("hvc", 0, NULL);
+
+ return 0;
+}
+console_initcall(hvc_rtas_console_init);
diff --git a/drivers/tty/hvc/hvc_udbg.c b/drivers/tty/hvc/hvc_udbg.c
new file mode 100644
index 0000000..a4c9913
--- /dev/null
+++ b/drivers/tty/hvc/hvc_udbg.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * udbg interface to hvc_console.c
+ *
+ * (C) Copyright David Gibson, IBM Corporation 2008.
+ */
+
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/irq.h>
+
+#include <asm/udbg.h>
+
+#include "hvc_console.h"
+
+struct hvc_struct *hvc_udbg_dev;
+
+static int hvc_udbg_put(uint32_t vtermno, const char *buf, int count)
+{
+ int i;
+
+ for (i = 0; i < count && udbg_putc; i++)
+ udbg_putc(buf[i]);
+
+ return i;
+}
+
+static int hvc_udbg_get(uint32_t vtermno, char *buf, int count)
+{
+ int i, c;
+
+ if (!udbg_getc_poll)
+ return 0;
+
+ for (i = 0; i < count; i++) {
+ if ((c = udbg_getc_poll()) == -1)
+ break;
+ buf[i] = c;
+ }
+
+ return i;
+}
+
+static const struct hv_ops hvc_udbg_ops = {
+ .get_chars = hvc_udbg_get,
+ .put_chars = hvc_udbg_put,
+};
+
+static int __init hvc_udbg_init(void)
+{
+ struct hvc_struct *hp;
+
+ if (!udbg_putc)
+ return -ENODEV;
+
+ BUG_ON(hvc_udbg_dev);
+
+ hp = hvc_alloc(0, 0, &hvc_udbg_ops, 16);
+ if (IS_ERR(hp))
+ return PTR_ERR(hp);
+
+ hvc_udbg_dev = hp;
+
+ return 0;
+}
+device_initcall(hvc_udbg_init);
+
+static int __init hvc_udbg_console_init(void)
+{
+ if (!udbg_putc)
+ return -ENODEV;
+
+ hvc_instantiate(0, 0, &hvc_udbg_ops);
+ add_preferred_console("hvc", 0, NULL);
+
+ return 0;
+}
+console_initcall(hvc_udbg_console_init);
diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c
new file mode 100644
index 0000000..59eaa62
--- /dev/null
+++ b/drivers/tty/hvc/hvc_vio.c
@@ -0,0 +1,468 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * vio driver interface to hvc_console.c
+ *
+ * This code was moved here to allow the remaining code to be reused as a
+ * generic polling mode with semi-reliable transport driver core to the
+ * console and tty subsystems.
+ *
+ *
+ * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
+ * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
+ * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
+ * Copyright (C) 2004 IBM Corporation
+ *
+ * Additional Author(s):
+ * Ryan S. Arnold <rsa@us.ibm.com>
+ *
+ * TODO:
+ *
+ * - handle error in sending hvsi protocol packets
+ * - retry nego on subsequent sends ?
+ */
+
+#undef DEBUG
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/console.h>
+
+#include <asm/hvconsole.h>
+#include <asm/vio.h>
+#include <asm/prom.h>
+#include <asm/hvsi.h>
+#include <asm/udbg.h>
+#include <asm/machdep.h>
+
+#include "hvc_console.h"
+
+static const char hvc_driver_name[] = "hvc_console";
+
+static const struct vio_device_id hvc_driver_table[] = {
+ {"serial", "hvterm1"},
+#ifndef HVC_OLD_HVSI
+ {"serial", "hvterm-protocol"},
+#endif
+ { "", "" }
+};
+
+typedef enum hv_protocol {
+ HV_PROTOCOL_RAW,
+ HV_PROTOCOL_HVSI
+} hv_protocol_t;
+
+struct hvterm_priv {
+ u32 termno; /* HV term number */
+ hv_protocol_t proto; /* Raw data or HVSI packets */
+ struct hvsi_priv hvsi; /* HVSI specific data */
+ spinlock_t buf_lock;
+ char buf[SIZE_VIO_GET_CHARS];
+ int left;
+ int offset;
+};
+static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES];
+/* For early boot console */
+static struct hvterm_priv hvterm_priv0;
+
+static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count)
+{
+ struct hvterm_priv *pv = hvterm_privs[vtermno];
+ unsigned long i;
+ unsigned long flags;
+ int got;
+
+ if (WARN_ON(!pv))
+ return 0;
+
+ spin_lock_irqsave(&pv->buf_lock, flags);
+
+ if (pv->left == 0) {
+ pv->offset = 0;
+ pv->left = hvc_get_chars(pv->termno, pv->buf, count);
+
+ /*
+ * Work around a HV bug where it gives us a null
+ * after every \r. -- paulus
+ */
+ for (i = 1; i < pv->left; ++i) {
+ if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') {
+ --pv->left;
+ if (i < pv->left) {
+ memmove(&pv->buf[i], &pv->buf[i+1],
+ pv->left - i);
+ }
+ }
+ }
+ }
+
+ got = min(count, pv->left);
+ memcpy(buf, &pv->buf[pv->offset], got);
+ pv->offset += got;
+ pv->left -= got;
+
+ spin_unlock_irqrestore(&pv->buf_lock, flags);
+
+ return got;
+}
+
+static int hvterm_raw_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+ struct hvterm_priv *pv = hvterm_privs[vtermno];
+
+ if (WARN_ON(!pv))
+ return 0;
+
+ return hvc_put_chars(pv->termno, buf, count);
+}
+
+static const struct hv_ops hvterm_raw_ops = {
+ .get_chars = hvterm_raw_get_chars,
+ .put_chars = hvterm_raw_put_chars,
+ .notifier_add = notifier_add_irq,
+ .notifier_del = notifier_del_irq,
+ .notifier_hangup = notifier_hangup_irq,
+};
+
+static int hvterm_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
+{
+ struct hvterm_priv *pv = hvterm_privs[vtermno];
+
+ if (WARN_ON(!pv))
+ return 0;
+
+ return hvsilib_get_chars(&pv->hvsi, buf, count);
+}
+
+static int hvterm_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
+{
+ struct hvterm_priv *pv = hvterm_privs[vtermno];
+
+ if (WARN_ON(!pv))
+ return 0;
+
+ return hvsilib_put_chars(&pv->hvsi, buf, count);
+}
+
+static int hvterm_hvsi_open(struct hvc_struct *hp, int data)
+{
+ struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+ int rc;
+
+ pr_devel("HVSI@%x: open !\n", pv->termno);
+
+ rc = notifier_add_irq(hp, data);
+ if (rc)
+ return rc;
+
+ return hvsilib_open(&pv->hvsi, hp);
+}
+
+static void hvterm_hvsi_close(struct hvc_struct *hp, int data)
+{
+ struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+ pr_devel("HVSI@%x: do close !\n", pv->termno);
+
+ hvsilib_close(&pv->hvsi, hp);
+
+ notifier_del_irq(hp, data);
+}
+
+void hvterm_hvsi_hangup(struct hvc_struct *hp, int data)
+{
+ struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+ pr_devel("HVSI@%x: do hangup !\n", pv->termno);
+
+ hvsilib_close(&pv->hvsi, hp);
+
+ notifier_hangup_irq(hp, data);
+}
+
+static int hvterm_hvsi_tiocmget(struct hvc_struct *hp)
+{
+ struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+ if (!pv)
+ return -EINVAL;
+ return pv->hvsi.mctrl;
+}
+
+static int hvterm_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
+ unsigned int clear)
+{
+ struct hvterm_priv *pv = hvterm_privs[hp->vtermno];
+
+ pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
+ pv->termno, set, clear);
+
+ if (set & TIOCM_DTR)
+ hvsilib_write_mctrl(&pv->hvsi, 1);
+ else if (clear & TIOCM_DTR)
+ hvsilib_write_mctrl(&pv->hvsi, 0);
+
+ return 0;
+}
+
+static const struct hv_ops hvterm_hvsi_ops = {
+ .get_chars = hvterm_hvsi_get_chars,
+ .put_chars = hvterm_hvsi_put_chars,
+ .notifier_add = hvterm_hvsi_open,
+ .notifier_del = hvterm_hvsi_close,
+ .notifier_hangup = hvterm_hvsi_hangup,
+ .tiocmget = hvterm_hvsi_tiocmget,
+ .tiocmset = hvterm_hvsi_tiocmset,
+};
+
+static void udbg_hvc_putc(char c)
+{
+ int count = -1;
+
+ if (!hvterm_privs[0])
+ return;
+
+ if (c == '\n')
+ udbg_hvc_putc('\r');
+
+ do {
+ switch(hvterm_privs[0]->proto) {
+ case HV_PROTOCOL_RAW:
+ count = hvterm_raw_put_chars(0, &c, 1);
+ break;
+ case HV_PROTOCOL_HVSI:
+ count = hvterm_hvsi_put_chars(0, &c, 1);
+ break;
+ }
+ } while(count == 0);
+}
+
+static int udbg_hvc_getc_poll(void)
+{
+ int rc = 0;
+ char c;
+
+ if (!hvterm_privs[0])
+ return -1;
+
+ switch(hvterm_privs[0]->proto) {
+ case HV_PROTOCOL_RAW:
+ rc = hvterm_raw_get_chars(0, &c, 1);
+ break;
+ case HV_PROTOCOL_HVSI:
+ rc = hvterm_hvsi_get_chars(0, &c, 1);
+ break;
+ }
+ if (!rc)
+ return -1;
+ return c;
+}
+
+static int udbg_hvc_getc(void)
+{
+ int ch;
+
+ if (!hvterm_privs[0])
+ return -1;
+
+ for (;;) {
+ ch = udbg_hvc_getc_poll();
+ if (ch == -1) {
+ /* This shouldn't be needed...but... */
+ volatile unsigned long delay;
+ for (delay=0; delay < 2000000; delay++)
+ ;
+ } else {
+ return ch;
+ }
+ }
+}
+
+static int hvc_vio_probe(struct vio_dev *vdev,
+ const struct vio_device_id *id)
+{
+ const struct hv_ops *ops;
+ struct hvc_struct *hp;
+ struct hvterm_priv *pv;
+ hv_protocol_t proto;
+ int i, termno = -1;
+
+ /* probed with invalid parameters. */
+ if (!vdev || !id)
+ return -EPERM;
+
+ if (of_device_is_compatible(vdev->dev.of_node, "hvterm1")) {
+ proto = HV_PROTOCOL_RAW;
+ ops = &hvterm_raw_ops;
+ } else if (of_device_is_compatible(vdev->dev.of_node, "hvterm-protocol")) {
+ proto = HV_PROTOCOL_HVSI;
+ ops = &hvterm_hvsi_ops;
+ } else {
+ pr_err("hvc_vio: Unknown protocol for %pOF\n", vdev->dev.of_node);
+ return -ENXIO;
+ }
+
+ pr_devel("hvc_vio_probe() device %pOF, using %s protocol\n",
+ vdev->dev.of_node,
+ proto == HV_PROTOCOL_RAW ? "raw" : "hvsi");
+
+ /* Is it our boot one ? */
+ if (hvterm_privs[0] == &hvterm_priv0 &&
+ vdev->unit_address == hvterm_priv0.termno) {
+ pv = hvterm_privs[0];
+ termno = 0;
+ pr_devel("->boot console, using termno 0\n");
+ }
+ /* nope, allocate a new one */
+ else {
+ for (i = 0; i < MAX_NR_HVC_CONSOLES && termno < 0; i++)
+ if (!hvterm_privs[i])
+ termno = i;
+ pr_devel("->non-boot console, using termno %d\n", termno);
+ if (termno < 0)
+ return -ENODEV;
+ pv = kzalloc(sizeof(struct hvterm_priv), GFP_KERNEL);
+ if (!pv)
+ return -ENOMEM;
+ pv->termno = vdev->unit_address;
+ pv->proto = proto;
+ spin_lock_init(&pv->buf_lock);
+ hvterm_privs[termno] = pv;
+ hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars,
+ pv->termno, 0);
+ }
+
+ hp = hvc_alloc(termno, vdev->irq, ops, MAX_VIO_PUT_CHARS);
+ if (IS_ERR(hp))
+ return PTR_ERR(hp);
+ dev_set_drvdata(&vdev->dev, hp);
+
+ /* register udbg if it's not there already for console 0 */
+ if (hp->index == 0 && !udbg_putc) {
+ udbg_putc = udbg_hvc_putc;
+ udbg_getc = udbg_hvc_getc;
+ udbg_getc_poll = udbg_hvc_getc_poll;
+ }
+
+ return 0;
+}
+
+static struct vio_driver hvc_vio_driver = {
+ .id_table = hvc_driver_table,
+ .probe = hvc_vio_probe,
+ .name = hvc_driver_name,
+ .driver = {
+ .suppress_bind_attrs = true,
+ },
+};
+
+static int __init hvc_vio_init(void)
+{
+ int rc;
+
+ /* Register as a vio device to receive callbacks */
+ rc = vio_register_driver(&hvc_vio_driver);
+
+ return rc;
+}
+device_initcall(hvc_vio_init); /* after drivers/tty/hvc/hvc_console.c */
+
+void __init hvc_vio_init_early(void)
+{
+ const __be32 *termno;
+ const char *name;
+ const struct hv_ops *ops;
+
+ /* find the boot console from /chosen/stdout */
+ if (!of_stdout)
+ return;
+ name = of_get_property(of_stdout, "name", NULL);
+ if (!name) {
+ printk(KERN_WARNING "stdout node missing 'name' property!\n");
+ return;
+ }
+
+ /* Check if it's a virtual terminal */
+ if (strncmp(name, "vty", 3) != 0)
+ return;
+ termno = of_get_property(of_stdout, "reg", NULL);
+ if (termno == NULL)
+ return;
+ hvterm_priv0.termno = of_read_number(termno, 1);
+ spin_lock_init(&hvterm_priv0.buf_lock);
+ hvterm_privs[0] = &hvterm_priv0;
+
+ /* Check the protocol */
+ if (of_device_is_compatible(of_stdout, "hvterm1")) {
+ hvterm_priv0.proto = HV_PROTOCOL_RAW;
+ ops = &hvterm_raw_ops;
+ }
+ else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) {
+ hvterm_priv0.proto = HV_PROTOCOL_HVSI;
+ ops = &hvterm_hvsi_ops;
+ hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
+ hvterm_priv0.termno, 1);
+ /* HVSI, perform the handshake now */
+ hvsilib_establish(&hvterm_priv0.hvsi);
+ } else
+ return;
+ udbg_putc = udbg_hvc_putc;
+ udbg_getc = udbg_hvc_getc;
+ udbg_getc_poll = udbg_hvc_getc_poll;
+#ifdef HVC_OLD_HVSI
+ /* When using the old HVSI driver don't register the HVC
+ * backend for HVSI, only do udbg
+ */
+ if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
+ return;
+#endif
+ /* Check whether the user has requested a different console. */
+ if (!strstr(boot_command_line, "console="))
+ add_preferred_console("hvc", 0, NULL);
+ hvc_instantiate(0, 0, ops);
+}
+
+/* call this from early_init() for a working debug console on
+ * vterm capable LPAR machines
+ */
+#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR
+void __init udbg_init_debug_lpar(void)
+{
+ /*
+ * If we're running as a hypervisor then we definitely can't call the
+ * hypervisor to print debug output (we *are* the hypervisor), so don't
+ * register if we detect that MSR_HV=1.
+ */
+ if (mfmsr() & MSR_HV)
+ return;
+
+ hvterm_privs[0] = &hvterm_priv0;
+ hvterm_priv0.termno = 0;
+ hvterm_priv0.proto = HV_PROTOCOL_RAW;
+ spin_lock_init(&hvterm_priv0.buf_lock);
+ udbg_putc = udbg_hvc_putc;
+ udbg_getc = udbg_hvc_getc;
+ udbg_getc_poll = udbg_hvc_getc_poll;
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR */
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI
+void __init udbg_init_debug_lpar_hvsi(void)
+{
+ /* See comment above in udbg_init_debug_lpar() */
+ if (mfmsr() & MSR_HV)
+ return;
+
+ hvterm_privs[0] = &hvterm_priv0;
+ hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO;
+ hvterm_priv0.proto = HV_PROTOCOL_HVSI;
+ spin_lock_init(&hvterm_priv0.buf_lock);
+ udbg_putc = udbg_hvc_putc;
+ udbg_getc = udbg_hvc_getc;
+ udbg_getc_poll = udbg_hvc_getc_poll;
+ hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
+ hvterm_priv0.termno, 1);
+ hvsilib_establish(&hvterm_priv0.hvsi);
+}
+#endif /* CONFIG_PPC_EARLY_DEBUG_LPAR_HVSI */
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
new file mode 100644
index 0000000..dc43fa9
--- /dev/null
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -0,0 +1,694 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * xen console driver interface to hvc_console.c
+ *
+ * (c) 2007 Gerd Hoffmann <kraxel@suse.de>
+ */
+
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/serial_core.h>
+
+#include <asm/io.h>
+#include <asm/xen/hypervisor.h>
+
+#include <xen/xen.h>
+#include <xen/interface/xen.h>
+#include <xen/hvm.h>
+#include <xen/grant_table.h>
+#include <xen/page.h>
+#include <xen/events.h>
+#include <xen/interface/io/console.h>
+#include <xen/interface/sched.h>
+#include <xen/hvc-console.h>
+#include <xen/xenbus.h>
+
+#include "hvc_console.h"
+
+#define HVC_COOKIE 0x58656e /* "Xen" in hex */
+
+struct xencons_info {
+ struct list_head list;
+ struct xenbus_device *xbdev;
+ struct xencons_interface *intf;
+ unsigned int evtchn;
+ struct hvc_struct *hvc;
+ int irq;
+ int vtermno;
+ grant_ref_t gntref;
+};
+
+static LIST_HEAD(xenconsoles);
+static DEFINE_SPINLOCK(xencons_lock);
+
+/* ------------------------------------------------------------------ */
+
+static struct xencons_info *vtermno_to_xencons(int vtermno)
+{
+ struct xencons_info *entry, *n, *ret = NULL;
+
+ if (list_empty(&xenconsoles))
+ return NULL;
+
+ list_for_each_entry_safe(entry, n, &xenconsoles, list) {
+ if (entry->vtermno == vtermno) {
+ ret = entry;
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static inline int xenbus_devid_to_vtermno(int devid)
+{
+ return devid + HVC_COOKIE;
+}
+
+static inline void notify_daemon(struct xencons_info *cons)
+{
+ /* Use evtchn: this is called early, before irq is set up. */
+ notify_remote_via_evtchn(cons->evtchn);
+}
+
+static int __write_console(struct xencons_info *xencons,
+ const char *data, int len)
+{
+ XENCONS_RING_IDX cons, prod;
+ struct xencons_interface *intf = xencons->intf;
+ int sent = 0;
+
+ cons = intf->out_cons;
+ prod = intf->out_prod;
+ mb(); /* update queue values before going on */
+ BUG_ON((prod - cons) > sizeof(intf->out));
+
+ while ((sent < len) && ((prod - cons) < sizeof(intf->out)))
+ intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++];
+
+ wmb(); /* write ring before updating pointer */
+ intf->out_prod = prod;
+
+ if (sent)
+ notify_daemon(xencons);
+ return sent;
+}
+
+static int domU_write_console(uint32_t vtermno, const char *data, int len)
+{
+ int ret = len;
+ struct xencons_info *cons = vtermno_to_xencons(vtermno);
+ if (cons == NULL)
+ return -EINVAL;
+
+ /*
+ * Make sure the whole buffer is emitted, polling if
+ * necessary. We don't ever want to rely on the hvc daemon
+ * because the most interesting console output is when the
+ * kernel is crippled.
+ */
+ while (len) {
+ int sent = __write_console(cons, data, len);
+
+ data += sent;
+ len -= sent;
+
+ if (unlikely(len))
+ HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
+ }
+
+ return ret;
+}
+
+static int domU_read_console(uint32_t vtermno, char *buf, int len)
+{
+ struct xencons_interface *intf;
+ XENCONS_RING_IDX cons, prod;
+ int recv = 0;
+ struct xencons_info *xencons = vtermno_to_xencons(vtermno);
+ if (xencons == NULL)
+ return -EINVAL;
+ intf = xencons->intf;
+
+ cons = intf->in_cons;
+ prod = intf->in_prod;
+ mb(); /* get pointers before reading ring */
+ BUG_ON((prod - cons) > sizeof(intf->in));
+
+ while (cons != prod && recv < len)
+ buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)];
+
+ mb(); /* read ring before consuming */
+ intf->in_cons = cons;
+
+ notify_daemon(xencons);
+ return recv;
+}
+
+static const struct hv_ops domU_hvc_ops = {
+ .get_chars = domU_read_console,
+ .put_chars = domU_write_console,
+ .notifier_add = notifier_add_irq,
+ .notifier_del = notifier_del_irq,
+ .notifier_hangup = notifier_hangup_irq,
+};
+
+static int dom0_read_console(uint32_t vtermno, char *buf, int len)
+{
+ return HYPERVISOR_console_io(CONSOLEIO_read, len, buf);
+}
+
+/*
+ * Either for a dom0 to write to the system console, or a domU with a
+ * debug version of Xen
+ */
+static int dom0_write_console(uint32_t vtermno, const char *str, int len)
+{
+ int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str);
+ if (rc < 0)
+ return rc;
+
+ return len;
+}
+
+static const struct hv_ops dom0_hvc_ops = {
+ .get_chars = dom0_read_console,
+ .put_chars = dom0_write_console,
+ .notifier_add = notifier_add_irq,
+ .notifier_del = notifier_del_irq,
+ .notifier_hangup = notifier_hangup_irq,
+};
+
+static int xen_hvm_console_init(void)
+{
+ int r;
+ uint64_t v = 0;
+ unsigned long gfn;
+ struct xencons_info *info;
+
+ if (!xen_hvm_domain())
+ return -ENODEV;
+
+ info = vtermno_to_xencons(HVC_COOKIE);
+ if (!info) {
+ info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ } else if (info->intf != NULL) {
+ /* already configured */
+ return 0;
+ }
+ /*
+ * If the toolstack (or the hypervisor) hasn't set these values, the
+ * default value is 0. Even though gfn = 0 and evtchn = 0 are
+ * theoretically correct values, in practice they never are and they
+ * mean that a legacy toolstack hasn't initialized the pv console correctly.
+ */
+ r = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
+ if (r < 0 || v == 0)
+ goto err;
+ info->evtchn = v;
+ v = 0;
+ r = hvm_get_parameter(HVM_PARAM_CONSOLE_PFN, &v);
+ if (r < 0 || v == 0)
+ goto err;
+ gfn = v;
+ info->intf = xen_remap(gfn << XEN_PAGE_SHIFT, XEN_PAGE_SIZE);
+ if (info->intf == NULL)
+ goto err;
+ info->vtermno = HVC_COOKIE;
+
+ spin_lock(&xencons_lock);
+ list_add_tail(&info->list, &xenconsoles);
+ spin_unlock(&xencons_lock);
+
+ return 0;
+err:
+ kfree(info);
+ return -ENODEV;
+}
+
+static int xencons_info_pv_init(struct xencons_info *info, int vtermno)
+{
+ info->evtchn = xen_start_info->console.domU.evtchn;
+ /* GFN == MFN for PV guest */
+ info->intf = gfn_to_virt(xen_start_info->console.domU.mfn);
+ info->vtermno = vtermno;
+
+ list_add_tail(&info->list, &xenconsoles);
+
+ return 0;
+}
+
+static int xen_pv_console_init(void)
+{
+ struct xencons_info *info;
+
+ if (!xen_pv_domain())
+ return -ENODEV;
+
+ if (!xen_start_info->console.domU.evtchn)
+ return -ENODEV;
+
+ info = vtermno_to_xencons(HVC_COOKIE);
+ if (!info) {
+ info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ } else if (info->intf != NULL) {
+ /* already configured */
+ return 0;
+ }
+ spin_lock(&xencons_lock);
+ xencons_info_pv_init(info, HVC_COOKIE);
+ spin_unlock(&xencons_lock);
+
+ return 0;
+}
+
+static int xen_initial_domain_console_init(void)
+{
+ struct xencons_info *info;
+
+ if (!xen_initial_domain())
+ return -ENODEV;
+
+ info = vtermno_to_xencons(HVC_COOKIE);
+ if (!info) {
+ info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ }
+
+ info->irq = bind_virq_to_irq(VIRQ_CONSOLE, 0, false);
+ info->vtermno = HVC_COOKIE;
+
+ spin_lock(&xencons_lock);
+ list_add_tail(&info->list, &xenconsoles);
+ spin_unlock(&xencons_lock);
+
+ return 0;
+}
+
+static void xen_console_update_evtchn(struct xencons_info *info)
+{
+ if (xen_hvm_domain()) {
+ uint64_t v = 0;
+ int err;
+
+ err = hvm_get_parameter(HVM_PARAM_CONSOLE_EVTCHN, &v);
+ if (!err && v)
+ info->evtchn = v;
+ } else
+ info->evtchn = xen_start_info->console.domU.evtchn;
+}
+
+void xen_console_resume(void)
+{
+ struct xencons_info *info = vtermno_to_xencons(HVC_COOKIE);
+ if (info != NULL && info->irq) {
+ if (!xen_initial_domain())
+ xen_console_update_evtchn(info);
+ rebind_evtchn_irq(info->evtchn, info->irq);
+ }
+}
+
+#ifdef CONFIG_HVC_XEN_FRONTEND
+static void xencons_disconnect_backend(struct xencons_info *info)
+{
+ if (info->irq > 0)
+ unbind_from_irqhandler(info->irq, NULL);
+ info->irq = 0;
+ if (info->evtchn > 0)
+ xenbus_free_evtchn(info->xbdev, info->evtchn);
+ info->evtchn = 0;
+ if (info->gntref > 0)
+ gnttab_free_grant_references(info->gntref);
+ info->gntref = 0;
+ if (info->hvc != NULL)
+ hvc_remove(info->hvc);
+ info->hvc = NULL;
+}
+
+static void xencons_free(struct xencons_info *info)
+{
+ free_page((unsigned long)info->intf);
+ info->intf = NULL;
+ info->vtermno = 0;
+ kfree(info);
+}
+
+static int xen_console_remove(struct xencons_info *info)
+{
+ xencons_disconnect_backend(info);
+ spin_lock(&xencons_lock);
+ list_del(&info->list);
+ spin_unlock(&xencons_lock);
+ if (info->xbdev != NULL)
+ xencons_free(info);
+ else {
+ if (xen_hvm_domain())
+ iounmap(info->intf);
+ kfree(info);
+ }
+ return 0;
+}
+
+static int xencons_remove(struct xenbus_device *dev)
+{
+ return xen_console_remove(dev_get_drvdata(&dev->dev));
+}
+
+static int xencons_connect_backend(struct xenbus_device *dev,
+ struct xencons_info *info)
+{
+ int ret, evtchn, devid, ref, irq;
+ struct xenbus_transaction xbt;
+ grant_ref_t gref_head;
+
+ ret = xenbus_alloc_evtchn(dev, &evtchn);
+ if (ret)
+ return ret;
+ info->evtchn = evtchn;
+ irq = bind_evtchn_to_irq(evtchn);
+ if (irq < 0)
+ return irq;
+ info->irq = irq;
+ devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
+ info->hvc = hvc_alloc(xenbus_devid_to_vtermno(devid),
+ irq, &domU_hvc_ops, 256);
+ if (IS_ERR(info->hvc))
+ return PTR_ERR(info->hvc);
+ ret = gnttab_alloc_grant_references(1, &gref_head);
+ if (ret < 0)
+ return ret;
+ info->gntref = gref_head;
+ ref = gnttab_claim_grant_reference(&gref_head);
+ if (ref < 0)
+ return ref;
+ gnttab_grant_foreign_access_ref(ref, info->xbdev->otherend_id,
+ virt_to_gfn(info->intf), 0);
+
+ again:
+ ret = xenbus_transaction_start(&xbt);
+ if (ret) {
+ xenbus_dev_fatal(dev, ret, "starting transaction");
+ return ret;
+ }
+ ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", ref);
+ if (ret)
+ goto error_xenbus;
+ ret = xenbus_printf(xbt, dev->nodename, "port", "%u",
+ evtchn);
+ if (ret)
+ goto error_xenbus;
+ ret = xenbus_transaction_end(xbt, 0);
+ if (ret) {
+ if (ret == -EAGAIN)
+ goto again;
+ xenbus_dev_fatal(dev, ret, "completing transaction");
+ return ret;
+ }
+
+ xenbus_switch_state(dev, XenbusStateInitialised);
+ return 0;
+
+ error_xenbus:
+ xenbus_transaction_end(xbt, 1);
+ xenbus_dev_fatal(dev, ret, "writing xenstore");
+ return ret;
+}
+
+static int xencons_probe(struct xenbus_device *dev,
+ const struct xenbus_device_id *id)
+{
+ int ret, devid;
+ struct xencons_info *info;
+
+ devid = dev->nodename[strlen(dev->nodename) - 1] - '0';
+ if (devid == 0)
+ return -ENODEV;
+
+ info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+ dev_set_drvdata(&dev->dev, info);
+ info->xbdev = dev;
+ info->vtermno = xenbus_devid_to_vtermno(devid);
+ info->intf = (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+ if (!info->intf)
+ goto error_nomem;
+
+ ret = xencons_connect_backend(dev, info);
+ if (ret < 0)
+ goto error;
+ spin_lock(&xencons_lock);
+ list_add_tail(&info->list, &xenconsoles);
+ spin_unlock(&xencons_lock);
+
+ return 0;
+
+ error_nomem:
+ ret = -ENOMEM;
+ xenbus_dev_fatal(dev, ret, "allocating device memory");
+ error:
+ xencons_disconnect_backend(info);
+ xencons_free(info);
+ return ret;
+}
+
+static int xencons_resume(struct xenbus_device *dev)
+{
+ struct xencons_info *info = dev_get_drvdata(&dev->dev);
+
+ xencons_disconnect_backend(info);
+ memset(info->intf, 0, XEN_PAGE_SIZE);
+ return xencons_connect_backend(dev, info);
+}
+
+static void xencons_backend_changed(struct xenbus_device *dev,
+ enum xenbus_state backend_state)
+{
+ switch (backend_state) {
+ case XenbusStateReconfiguring:
+ case XenbusStateReconfigured:
+ case XenbusStateInitialising:
+ case XenbusStateInitialised:
+ case XenbusStateUnknown:
+ break;
+
+ case XenbusStateInitWait:
+ break;
+
+ case XenbusStateConnected:
+ xenbus_switch_state(dev, XenbusStateConnected);
+ break;
+
+ case XenbusStateClosed:
+ if (dev->state == XenbusStateClosed)
+ break;
+ /* Missed the backend's CLOSING state -- fallthrough */
+ case XenbusStateClosing:
+ xenbus_frontend_closed(dev);
+ break;
+ }
+}
+
+static const struct xenbus_device_id xencons_ids[] = {
+ { "console" },
+ { "" }
+};
+
+static struct xenbus_driver xencons_driver = {
+ .name = "xenconsole",
+ .ids = xencons_ids,
+ .probe = xencons_probe,
+ .remove = xencons_remove,
+ .resume = xencons_resume,
+ .otherend_changed = xencons_backend_changed,
+};
+#endif /* CONFIG_HVC_XEN_FRONTEND */
+
+static int __init xen_hvc_init(void)
+{
+ int r;
+ struct xencons_info *info;
+ const struct hv_ops *ops;
+
+ if (!xen_domain())
+ return -ENODEV;
+
+ if (xen_initial_domain()) {
+ ops = &dom0_hvc_ops;
+ r = xen_initial_domain_console_init();
+ if (r < 0)
+ return r;
+ info = vtermno_to_xencons(HVC_COOKIE);
+ } else {
+ ops = &domU_hvc_ops;
+ if (xen_hvm_domain())
+ r = xen_hvm_console_init();
+ else
+ r = xen_pv_console_init();
+ if (r < 0)
+ return r;
+
+ info = vtermno_to_xencons(HVC_COOKIE);
+ info->irq = bind_evtchn_to_irq(info->evtchn);
+ }
+ if (info->irq < 0)
+ info->irq = 0; /* NO_IRQ */
+ else
+ irq_set_noprobe(info->irq);
+
+ info->hvc = hvc_alloc(HVC_COOKIE, info->irq, ops, 256);
+ if (IS_ERR(info->hvc)) {
+ r = PTR_ERR(info->hvc);
+ spin_lock(&xencons_lock);
+ list_del(&info->list);
+ spin_unlock(&xencons_lock);
+ if (info->irq)
+ unbind_from_irqhandler(info->irq, NULL);
+ kfree(info);
+ return r;
+ }
+
+ r = 0;
+#ifdef CONFIG_HVC_XEN_FRONTEND
+ r = xenbus_register_frontend(&xencons_driver);
+#endif
+ return r;
+}
+device_initcall(xen_hvc_init);
+
+static int xen_cons_init(void)
+{
+ const struct hv_ops *ops;
+
+ if (!xen_domain())
+ return 0;
+
+ if (xen_initial_domain())
+ ops = &dom0_hvc_ops;
+ else {
+ int r;
+ ops = &domU_hvc_ops;
+
+ if (xen_hvm_domain())
+ r = xen_hvm_console_init();
+ else
+ r = xen_pv_console_init();
+ if (r < 0)
+ return r;
+ }
+
+ hvc_instantiate(HVC_COOKIE, 0, ops);
+ return 0;
+}
+console_initcall(xen_cons_init);
+
+#ifdef CONFIG_X86
+static void xen_hvm_early_write(uint32_t vtermno, const char *str, int len)
+{
+ if (xen_cpuid_base())
+ outsb(0xe9, str, len);
+}
+#else
+static void xen_hvm_early_write(uint32_t vtermno, const char *str, int len) { }
+#endif
+
+#ifdef CONFIG_EARLY_PRINTK
+static int __init xenboot_setup_console(struct console *console, char *string)
+{
+ static struct xencons_info xenboot;
+
+ if (xen_initial_domain())
+ return 0;
+ if (!xen_pv_domain())
+ return -ENODEV;
+
+ return xencons_info_pv_init(&xenboot, 0);
+}
+
+static void xenboot_write_console(struct console *console, const char *string,
+ unsigned len)
+{
+ unsigned int linelen, off = 0;
+ const char *pos;
+
+ if (!xen_pv_domain()) {
+ xen_hvm_early_write(0, string, len);
+ return;
+ }
+
+ dom0_write_console(0, string, len);
+
+ if (xen_initial_domain())
+ return;
+
+ domU_write_console(0, "(early) ", 8);
+ while (off < len && NULL != (pos = strchr(string+off, '\n'))) {
+ linelen = pos-string+off;
+ if (off + linelen > len)
+ break;
+ domU_write_console(0, string+off, linelen);
+ domU_write_console(0, "\r\n", 2);
+ off += linelen + 1;
+ }
+ if (off < len)
+ domU_write_console(0, string+off, len-off);
+}
+
+struct console xenboot_console = {
+ .name = "xenboot",
+ .write = xenboot_write_console,
+ .setup = xenboot_setup_console,
+ .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
+ .index = -1,
+};
+#endif /* CONFIG_EARLY_PRINTK */
+
+void xen_raw_console_write(const char *str)
+{
+ ssize_t len = strlen(str);
+ int rc = 0;
+
+ if (xen_domain()) {
+ rc = dom0_write_console(0, str, len);
+ if (rc != -ENOSYS || !xen_hvm_domain())
+ return;
+ }
+ xen_hvm_early_write(0, str, len);
+}
+
+void xen_raw_printk(const char *fmt, ...)
+{
+ static char buf[512];
+ va_list ap;
+
+ va_start(ap, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, ap);
+ va_end(ap);
+
+ xen_raw_console_write(buf);
+}
+
+static void xenboot_earlycon_write(struct console *console,
+ const char *string,
+ unsigned len)
+{
+ dom0_write_console(0, string, len);
+}
+
+static int __init xenboot_earlycon_setup(struct earlycon_device *device,
+ const char *opt)
+{
+ device->con->write = xenboot_earlycon_write;
+ return 0;
+}
+EARLYCON_DECLARE(xenboot, xenboot_earlycon_setup);
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
new file mode 100644
index 0000000..cb4db1b
--- /dev/null
+++ b/drivers/tty/hvc/hvcs.c
@@ -0,0 +1,1602 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IBM eServer Hypervisor Virtual Console Server Device Driver
+ * Copyright (C) 2003, 2004 IBM Corp.
+ * Ryan S. Arnold (rsa@us.ibm.com)
+ *
+ * Author(s) : Ryan S. Arnold <rsa@us.ibm.com>
+ *
+ * This is the device driver for the IBM Hypervisor Virtual Console Server,
+ * "hvcs". The IBM hvcs provides a tty driver interface to allow Linux
+ * user space applications access to the system consoles of logically
+ * partitioned operating systems, e.g. Linux, running on the same partitioned
+ * Power5 ppc64 system. Physical hardware consoles per partition are not
+ * practical on this hardware so system consoles are accessed by this driver
+ * using inter-partition firmware interfaces to virtual terminal devices.
+ *
+ * A vty is known to the HMC as a "virtual serial server adapter". It is a
+ * virtual terminal device that is created by firmware upon partition creation
+ * to act as a partitioned OS's console device.
+ *
+ * Firmware dynamically (via hotplug) exposes vty-servers to a running ppc64
+ * Linux system upon their creation by the HMC or their exposure during boot.
+ * The non-user interactive backend of this driver is implemented as a vio
+ * device driver so that it can receive notification of vty-server lifetimes
+ * after it registers with the vio bus to handle vty-server probe and remove
+ * callbacks.
+ *
+ * Many vty-servers can be configured to connect to one vty, but a vty can
+ * only be actively connected to by a single vty-server, in any manner, at one
+ * time. If the HMC is currently hosting the console for a target Linux
+ * partition; attempts to open the tty device to the partition's console using
+ * the hvcs on any partition will return -EBUSY with every open attempt until
+ * the HMC frees the connection between its vty-server and the desired
+ * partition's vty device. Conversely, a vty-server may only be connected to
+ * a single vty at one time even though it may have several configured vty
+ * partner possibilities.
+ *
+ * Firmware does not provide notification of vty partner changes to this
+ * driver. This means that an HMC Super Admin may add or remove partner vtys
+ * from a vty-server's partner list but the changes will not be signaled to
+ * the vty-server. Firmware only notifies the driver when a vty-server is
+ * added or removed from the system. To compensate for this deficiency, this
+ * driver implements a sysfs update attribute which provides a method for
+ * rescanning partner information upon a user's request.
+ *
+ * Each vty-server, prior to being exposed to this driver is reference counted
+ * using the 2.6 Linux kernel kref construct.
+ *
+ * For direction on installation and usage of this driver please reference
+ * Documentation/powerpc/hvcs.txt.
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/kref.h>
+#include <linux/kthread.h>
+#include <linux/list.h>
+#include <linux/major.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/stat.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <asm/hvconsole.h>
+#include <asm/hvcserver.h>
+#include <linux/uaccess.h>
+#include <asm/vio.h>
+
+/*
+ * 1.3.0 -> 1.3.1 In hvcs_open memset(..,0x00,..) instead of memset(..,0x3F,00).
+ * Removed braces around single statements following conditionals. Removed '=
+ * 0' after static int declarations since these default to zero. Removed
+ * list_for_each_safe() and replaced with list_for_each_entry() in
+ * hvcs_get_by_index(). The 'safe' version is un-needed now that the driver is
+ * using spinlocks. Changed spin_lock_irqsave() to spin_lock() when locking
+ * hvcs_structs_lock and hvcs_pi_lock since these are not touched in an int
+ * handler. Initialized hvcs_structs_lock and hvcs_pi_lock to
+ * SPIN_LOCK_UNLOCKED at declaration time rather than in hvcs_module_init().
+ * Added spin_lock around list_del() in destroy_hvcs_struct() to protect the
+ * list traversals from a deletion. Removed '= NULL' from pointer declaration
+ * statements since they are initialized NULL by default. Removed wmb()
+ * instances from hvcs_try_write(). They probably aren't needed with locking in
+ * place. Added check and cleanup for hvcs_pi_buff = kmalloc() in
+ * hvcs_module_init(). Exposed hvcs_struct.index via a sysfs attribute so that
+ * the coupling between /dev/hvcs* and a vty-server can be automatically
+ * determined. Moved kobject_put() in hvcs_open outside of the
+ * spin_unlock_irqrestore().
+ *
+ * 1.3.1 -> 1.3.2 Changed method for determining hvcs_struct->index and had it
+ * align with how the tty layer always assigns the lowest index available. This
+ * change resulted in a list of ints that denotes which indexes are available.
+ * Device additions and removals use the new hvcs_get_index() and
+ * hvcs_return_index() helper functions. The list is created with
+ * hvsc_alloc_index_list() and it is destroyed with hvcs_free_index_list().
+ * Without these fixes hotplug vty-server adapter support goes crazy with this
+ * driver if the user removes a vty-server adapter. Moved free_irq() outside of
+ * the hvcs_final_close() function in order to get it out of the spinlock.
+ * Rearranged hvcs_close(). Cleaned up some printks and did some housekeeping
+ * on the changelog. Removed local CLC_LENGTH and used HVCS_CLC_LENGTH from
+ * arch/powerepc/include/asm/hvcserver.h
+ *
+ * 1.3.2 -> 1.3.3 Replaced yield() in hvcs_close() with tty_wait_until_sent() to
+ * prevent possible lockup with realtime scheduling as similarly pointed out by
+ * akpm in hvc_console. Changed resulted in the removal of hvcs_final_close()
+ * to reorder cleanup operations and prevent discarding of pending data during
+ * an hvcs_close(). Removed spinlock protection of hvcs_struct data members in
+ * hvcs_write_room() and hvcs_chars_in_buffer() because they aren't needed.
+ */
+
+#define HVCS_DRIVER_VERSION "1.3.3"
+
+MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>");
+MODULE_DESCRIPTION("IBM hvcs (Hypervisor Virtual Console Server) Driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(HVCS_DRIVER_VERSION);
+
+/*
+ * Wait this long per iteration while trying to push buffered data to the
+ * hypervisor before allowing the tty to complete a close operation.
+ */
+#define HVCS_CLOSE_WAIT (HZ/100) /* 1/10 of a second */
+
+/*
+ * Since the Linux TTY code does not currently (2-04-2004) support dynamic
+ * addition of tty derived devices and we shouldn't allocate thousands of
+ * tty_device pointers when the number of vty-server & vty partner connections
+ * will most often be much lower than this, we'll arbitrarily allocate
+ * HVCS_DEFAULT_SERVER_ADAPTERS tty_structs and cdev's by default when we
+ * register the tty_driver. This can be overridden using an insmod parameter.
+ */
+#define HVCS_DEFAULT_SERVER_ADAPTERS 64
+
+/*
+ * The user can't insmod with more than HVCS_MAX_SERVER_ADAPTERS hvcs device
+ * nodes as a sanity check. Theoretically there can be over 1 Billion
+ * vty-server & vty partner connections.
+ */
+#define HVCS_MAX_SERVER_ADAPTERS 1024
+
+/*
+ * We let Linux assign us a major number and we start the minors at zero. There
+ * is no intuitive mapping between minor number and the target vty-server
+ * adapter except that each new vty-server adapter is always assigned to the
+ * smallest minor number available.
+ */
+#define HVCS_MINOR_START 0
+
+/*
+ * The hcall interface involves putting 8 chars into each of two registers.
+ * We load up those 2 registers (in arch/powerpc/platforms/pseries/hvconsole.c)
+ * by casting char[16] to long[2]. It would work without __ALIGNED__, but a
+ * little (tiny) bit slower because an unaligned load is slower than aligned
+ * load.
+ */
+#define __ALIGNED__ __attribute__((__aligned__(8)))
+
+/*
+ * How much data can firmware send with each hvc_put_chars()? Maybe this
+ * should be moved into an architecture specific area.
+ */
+#define HVCS_BUFF_LEN 16
+
+/*
+ * This is the maximum amount of data we'll let the user send us (hvcs_write) at
+ * once in a chunk as a sanity check.
+ */
+#define HVCS_MAX_FROM_USER 4096
+
+/*
+ * Be careful when adding flags to this line discipline. Don't add anything
+ * that will cause echoing or we'll go into recursive loop echoing chars back
+ * and forth with the console drivers.
+ */
+static const struct ktermios hvcs_tty_termios = {
+ .c_iflag = IGNBRK | IGNPAR,
+ .c_oflag = OPOST,
+ .c_cflag = B38400 | CS8 | CREAD | HUPCL,
+ .c_cc = INIT_C_CC,
+ .c_ispeed = 38400,
+ .c_ospeed = 38400
+};
+
+/*
+ * This value is used to take the place of a command line parameter when the
+ * module is inserted. It starts as -1 and stays as such if the user doesn't
+ * specify a module insmod parameter. If they DO specify one then it is set to
+ * the value of the integer passed in.
+ */
+static int hvcs_parm_num_devs = -1;
+module_param(hvcs_parm_num_devs, int, 0);
+
+static const char hvcs_driver_name[] = "hvcs";
+static const char hvcs_device_node[] = "hvcs";
+static const char hvcs_driver_string[]
+ = "IBM hvcs (Hypervisor Virtual Console Server) Driver";
+
+/* Status of partner info rescan triggered via sysfs. */
+static int hvcs_rescan_status;
+
+static struct tty_driver *hvcs_tty_driver;
+
+/*
+ * In order to be somewhat sane this driver always associates the hvcs_struct
+ * index element with the numerically equal tty->index. This means that a
+ * hotplugged vty-server adapter will always map to the lowest index valued
+ * device node. If vty-servers were hotplug removed from the system and then
+ * new ones added the new vty-server may have the largest slot number of all
+ * the vty-server adapters in the partition but it may have the lowest dev node
+ * index of all the adapters due to the hole left by the hotplug removed
+ * adapter. There are a set of functions provided to get the lowest index for
+ * a new device as well as return the index to the list. This list is allocated
+ * with a number of elements equal to the number of device nodes requested when
+ * the module was inserted.
+ */
+static int *hvcs_index_list;
+
+/*
+ * How large is the list? This is kept for traversal since the list is
+ * dynamically created.
+ */
+static int hvcs_index_count;
+
+/*
+ * Used by the khvcsd to pick up I/O operations when the kernel_thread is
+ * already awake but potentially shifted to TASK_INTERRUPTIBLE state.
+ */
+static int hvcs_kicked;
+
+/*
+ * Use by the kthread construct for task operations like waking the sleeping
+ * thread and stopping the kthread.
+ */
+static struct task_struct *hvcs_task;
+
+/*
+ * We allocate this for the use of all of the hvcs_structs when they fetch
+ * partner info.
+ */
+static unsigned long *hvcs_pi_buff;
+
+/* Only allow one hvcs_struct to use the hvcs_pi_buff at a time. */
+static DEFINE_SPINLOCK(hvcs_pi_lock);
+
+/* One vty-server per hvcs_struct */
+struct hvcs_struct {
+ struct tty_port port;
+ spinlock_t lock;
+
+ /*
+ * This index identifies this hvcs device as the complement to a
+ * specific tty index.
+ */
+ unsigned int index;
+
+ /*
+ * Used to tell the driver kernel_thread what operations need to take
+ * place upon this hvcs_struct instance.
+ */
+ int todo_mask;
+
+ /*
+ * This buffer is required so that when hvcs_write_room() reports that
+ * it can send HVCS_BUFF_LEN characters that it will buffer the full
+ * HVCS_BUFF_LEN characters if need be. This is essential for opost
+ * writes since they do not do high level buffering and expect to be
+ * able to send what the driver commits to sending buffering
+ * [e.g. tab to space conversions in n_tty.c opost()].
+ */
+ char buffer[HVCS_BUFF_LEN];
+ int chars_in_buffer;
+
+ /*
+ * Any variable below is valid before a tty is connected and
+ * stays valid after the tty is disconnected. These shouldn't be
+ * whacked until the kobject refcount reaches zero though some entries
+ * may be changed via sysfs initiatives.
+ */
+ int connected; /* is the vty-server currently connected to a vty? */
+ uint32_t p_unit_address; /* partner unit address */
+ uint32_t p_partition_ID; /* partner partition ID */
+ char p_location_code[HVCS_CLC_LENGTH + 1]; /* CLC + Null Term */
+ struct list_head next; /* list management */
+ struct vio_dev *vdev;
+};
+
+static LIST_HEAD(hvcs_structs);
+static DEFINE_SPINLOCK(hvcs_structs_lock);
+static DEFINE_MUTEX(hvcs_init_mutex);
+
+static void hvcs_unthrottle(struct tty_struct *tty);
+static void hvcs_throttle(struct tty_struct *tty);
+static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance);
+
+static int hvcs_write(struct tty_struct *tty,
+ const unsigned char *buf, int count);
+static int hvcs_write_room(struct tty_struct *tty);
+static int hvcs_chars_in_buffer(struct tty_struct *tty);
+
+static int hvcs_has_pi(struct hvcs_struct *hvcsd);
+static void hvcs_set_pi(struct hvcs_partner_info *pi,
+ struct hvcs_struct *hvcsd);
+static int hvcs_get_pi(struct hvcs_struct *hvcsd);
+static int hvcs_rescan_devices_list(void);
+
+static int hvcs_partner_connect(struct hvcs_struct *hvcsd);
+static void hvcs_partner_free(struct hvcs_struct *hvcsd);
+
+static int hvcs_enable_device(struct hvcs_struct *hvcsd,
+ uint32_t unit_address, unsigned int irq, struct vio_dev *dev);
+
+static int hvcs_open(struct tty_struct *tty, struct file *filp);
+static void hvcs_close(struct tty_struct *tty, struct file *filp);
+static void hvcs_hangup(struct tty_struct * tty);
+
+static int hvcs_probe(struct vio_dev *dev,
+ const struct vio_device_id *id);
+static int hvcs_remove(struct vio_dev *dev);
+static int __init hvcs_module_init(void);
+static void __exit hvcs_module_exit(void);
+static int hvcs_initialize(void);
+
+#define HVCS_SCHED_READ 0x00000001
+#define HVCS_QUICK_READ 0x00000002
+#define HVCS_TRY_WRITE 0x00000004
+#define HVCS_READ_MASK (HVCS_SCHED_READ | HVCS_QUICK_READ)
+
+static inline struct hvcs_struct *from_vio_dev(struct vio_dev *viod)
+{
+ return dev_get_drvdata(&viod->dev);
+}
+/* The sysfs interface for the driver and devices */
+
+static ssize_t hvcs_partner_vtys_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct vio_dev *viod = to_vio_dev(dev);
+ struct hvcs_struct *hvcsd = from_vio_dev(viod);
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ retval = sprintf(buf, "%X\n", hvcsd->p_unit_address);
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ return retval;
+}
+static DEVICE_ATTR(partner_vtys, S_IRUGO, hvcs_partner_vtys_show, NULL);
+
+static ssize_t hvcs_partner_clcs_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct vio_dev *viod = to_vio_dev(dev);
+ struct hvcs_struct *hvcsd = from_vio_dev(viod);
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]);
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ return retval;
+}
+static DEVICE_ATTR(partner_clcs, S_IRUGO, hvcs_partner_clcs_show, NULL);
+
+static ssize_t hvcs_current_vty_store(struct device *dev, struct device_attribute *attr, const char * buf,
+ size_t count)
+{
+ /*
+ * Don't need this feature at the present time because firmware doesn't
+ * yet support multiple partners.
+ */
+ printk(KERN_INFO "HVCS: Denied current_vty change: -EPERM.\n");
+ return -EPERM;
+}
+
+static ssize_t hvcs_current_vty_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct vio_dev *viod = to_vio_dev(dev);
+ struct hvcs_struct *hvcsd = from_vio_dev(viod);
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]);
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ return retval;
+}
+
+static DEVICE_ATTR(current_vty,
+ S_IRUGO | S_IWUSR, hvcs_current_vty_show, hvcs_current_vty_store);
+
+static ssize_t hvcs_vterm_state_store(struct device *dev, struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct vio_dev *viod = to_vio_dev(dev);
+ struct hvcs_struct *hvcsd = from_vio_dev(viod);
+ unsigned long flags;
+
+ /* writing a '0' to this sysfs entry will result in the disconnect. */
+ if (simple_strtol(buf, NULL, 0) != 0)
+ return -EINVAL;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+
+ if (hvcsd->port.count > 0) {
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ printk(KERN_INFO "HVCS: vterm state unchanged. "
+ "The hvcs device node is still in use.\n");
+ return -EPERM;
+ }
+
+ if (hvcsd->connected == 0) {
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ printk(KERN_INFO "HVCS: vterm state unchanged. The"
+ " vty-server is not connected to a vty.\n");
+ return -EPERM;
+ }
+
+ hvcs_partner_free(hvcsd);
+ printk(KERN_INFO "HVCS: Closed vty-server@%X and"
+ " partner vty@%X:%d connection.\n",
+ hvcsd->vdev->unit_address,
+ hvcsd->p_unit_address,
+ (uint32_t)hvcsd->p_partition_ID);
+
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ return count;
+}
+
+static ssize_t hvcs_vterm_state_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct vio_dev *viod = to_vio_dev(dev);
+ struct hvcs_struct *hvcsd = from_vio_dev(viod);
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ retval = sprintf(buf, "%d\n", hvcsd->connected);
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ return retval;
+}
+static DEVICE_ATTR(vterm_state, S_IRUGO | S_IWUSR,
+ hvcs_vterm_state_show, hvcs_vterm_state_store);
+
+static ssize_t hvcs_index_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct vio_dev *viod = to_vio_dev(dev);
+ struct hvcs_struct *hvcsd = from_vio_dev(viod);
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ retval = sprintf(buf, "%d\n", hvcsd->index);
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ return retval;
+}
+
+static DEVICE_ATTR(index, S_IRUGO, hvcs_index_show, NULL);
+
+static struct attribute *hvcs_attrs[] = {
+ &dev_attr_partner_vtys.attr,
+ &dev_attr_partner_clcs.attr,
+ &dev_attr_current_vty.attr,
+ &dev_attr_vterm_state.attr,
+ &dev_attr_index.attr,
+ NULL,
+};
+
+static struct attribute_group hvcs_attr_group = {
+ .attrs = hvcs_attrs,
+};
+
+static ssize_t rescan_show(struct device_driver *ddp, char *buf)
+{
+ /* A 1 means it is updating, a 0 means it is done updating */
+ return snprintf(buf, PAGE_SIZE, "%d\n", hvcs_rescan_status);
+}
+
+static ssize_t rescan_store(struct device_driver *ddp, const char * buf,
+ size_t count)
+{
+ if ((simple_strtol(buf, NULL, 0) != 1)
+ && (hvcs_rescan_status != 0))
+ return -EINVAL;
+
+ hvcs_rescan_status = 1;
+ printk(KERN_INFO "HVCS: rescanning partner info for all"
+ " vty-servers.\n");
+ hvcs_rescan_devices_list();
+ hvcs_rescan_status = 0;
+ return count;
+}
+
+static DRIVER_ATTR_RW(rescan);
+
+static void hvcs_kick(void)
+{
+ hvcs_kicked = 1;
+ wmb();
+ wake_up_process(hvcs_task);
+}
+
+static void hvcs_unthrottle(struct tty_struct *tty)
+{
+ struct hvcs_struct *hvcsd = tty->driver_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ hvcsd->todo_mask |= HVCS_SCHED_READ;
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ hvcs_kick();
+}
+
+static void hvcs_throttle(struct tty_struct *tty)
+{
+ struct hvcs_struct *hvcsd = tty->driver_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ vio_disable_interrupts(hvcsd->vdev);
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+}
+
+/*
+ * If the device is being removed we don't have to worry about this interrupt
+ * handler taking any further interrupts because they are disabled which means
+ * the hvcs_struct will always be valid in this handler.
+ */
+static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance)
+{
+ struct hvcs_struct *hvcsd = dev_instance;
+
+ spin_lock(&hvcsd->lock);
+ vio_disable_interrupts(hvcsd->vdev);
+ hvcsd->todo_mask |= HVCS_SCHED_READ;
+ spin_unlock(&hvcsd->lock);
+ hvcs_kick();
+
+ return IRQ_HANDLED;
+}
+
+/* This function must be called with the hvcsd->lock held */
+static void hvcs_try_write(struct hvcs_struct *hvcsd)
+{
+ uint32_t unit_address = hvcsd->vdev->unit_address;
+ struct tty_struct *tty = hvcsd->port.tty;
+ int sent;
+
+ if (hvcsd->todo_mask & HVCS_TRY_WRITE) {
+ /* won't send partial writes */
+ sent = hvc_put_chars(unit_address,
+ &hvcsd->buffer[0],
+ hvcsd->chars_in_buffer );
+ if (sent > 0) {
+ hvcsd->chars_in_buffer = 0;
+ /* wmb(); */
+ hvcsd->todo_mask &= ~(HVCS_TRY_WRITE);
+ /* wmb(); */
+
+ /*
+ * We are still obligated to deliver the data to the
+ * hypervisor even if the tty has been closed because
+ * we committed to delivering it. But don't try to wake
+ * a non-existent tty.
+ */
+ if (tty) {
+ tty_wakeup(tty);
+ }
+ }
+ }
+}
+
+static int hvcs_io(struct hvcs_struct *hvcsd)
+{
+ uint32_t unit_address;
+ struct tty_struct *tty;
+ char buf[HVCS_BUFF_LEN] __ALIGNED__;
+ unsigned long flags;
+ int got = 0;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+
+ unit_address = hvcsd->vdev->unit_address;
+ tty = hvcsd->port.tty;
+
+ hvcs_try_write(hvcsd);
+
+ if (!tty || tty_throttled(tty)) {
+ hvcsd->todo_mask &= ~(HVCS_READ_MASK);
+ goto bail;
+ } else if (!(hvcsd->todo_mask & (HVCS_READ_MASK)))
+ goto bail;
+
+ /* remove the read masks */
+ hvcsd->todo_mask &= ~(HVCS_READ_MASK);
+
+ if (tty_buffer_request_room(&hvcsd->port, HVCS_BUFF_LEN) >= HVCS_BUFF_LEN) {
+ got = hvc_get_chars(unit_address,
+ &buf[0],
+ HVCS_BUFF_LEN);
+ tty_insert_flip_string(&hvcsd->port, buf, got);
+ }
+
+ /* Give the TTY time to process the data we just sent. */
+ if (got)
+ hvcsd->todo_mask |= HVCS_QUICK_READ;
+
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ /* This is synch because tty->low_latency == 1 */
+ if(got)
+ tty_flip_buffer_push(&hvcsd->port);
+
+ if (!got) {
+ /* Do this _after_ the flip_buffer_push */
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ vio_enable_interrupts(hvcsd->vdev);
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ }
+
+ return hvcsd->todo_mask;
+
+ bail:
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ return hvcsd->todo_mask;
+}
+
+static int khvcsd(void *unused)
+{
+ struct hvcs_struct *hvcsd;
+ int hvcs_todo_mask;
+
+ __set_current_state(TASK_RUNNING);
+
+ do {
+ hvcs_todo_mask = 0;
+ hvcs_kicked = 0;
+ wmb();
+
+ spin_lock(&hvcs_structs_lock);
+ list_for_each_entry(hvcsd, &hvcs_structs, next) {
+ hvcs_todo_mask |= hvcs_io(hvcsd);
+ }
+ spin_unlock(&hvcs_structs_lock);
+
+ /*
+ * If any of the hvcs adapters want to try a write or quick read
+ * don't schedule(), yield a smidgen then execute the hvcs_io
+ * thread again for those that want the write.
+ */
+ if (hvcs_todo_mask & (HVCS_TRY_WRITE | HVCS_QUICK_READ)) {
+ yield();
+ continue;
+ }
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (!hvcs_kicked)
+ schedule();
+ __set_current_state(TASK_RUNNING);
+ } while (!kthread_should_stop());
+
+ return 0;
+}
+
+static const struct vio_device_id hvcs_driver_table[] = {
+ {"serial-server", "hvterm2"},
+ { "", "" }
+};
+MODULE_DEVICE_TABLE(vio, hvcs_driver_table);
+
+static void hvcs_return_index(int index)
+{
+ /* Paranoia check */
+ if (!hvcs_index_list)
+ return;
+ if (index < 0 || index >= hvcs_index_count)
+ return;
+ if (hvcs_index_list[index] == -1)
+ return;
+ else
+ hvcs_index_list[index] = -1;
+}
+
+static void hvcs_destruct_port(struct tty_port *p)
+{
+ struct hvcs_struct *hvcsd = container_of(p, struct hvcs_struct, port);
+ struct vio_dev *vdev;
+ unsigned long flags;
+
+ spin_lock(&hvcs_structs_lock);
+ spin_lock_irqsave(&hvcsd->lock, flags);
+
+ /* the list_del poisons the pointers */
+ list_del(&(hvcsd->next));
+
+ if (hvcsd->connected == 1) {
+ hvcs_partner_free(hvcsd);
+ printk(KERN_INFO "HVCS: Closed vty-server@%X and"
+ " partner vty@%X:%d connection.\n",
+ hvcsd->vdev->unit_address,
+ hvcsd->p_unit_address,
+ (uint32_t)hvcsd->p_partition_ID);
+ }
+ printk(KERN_INFO "HVCS: Destroyed hvcs_struct for vty-server@%X.\n",
+ hvcsd->vdev->unit_address);
+
+ vdev = hvcsd->vdev;
+ hvcsd->vdev = NULL;
+
+ hvcsd->p_unit_address = 0;
+ hvcsd->p_partition_ID = 0;
+ hvcs_return_index(hvcsd->index);
+ memset(&hvcsd->p_location_code[0], 0x00, HVCS_CLC_LENGTH + 1);
+
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ spin_unlock(&hvcs_structs_lock);
+
+ sysfs_remove_group(&vdev->dev.kobj, &hvcs_attr_group);
+
+ kfree(hvcsd);
+}
+
+static const struct tty_port_operations hvcs_port_ops = {
+ .destruct = hvcs_destruct_port,
+};
+
+static int hvcs_get_index(void)
+{
+ int i;
+ /* Paranoia check */
+ if (!hvcs_index_list) {
+ printk(KERN_ERR "HVCS: hvcs_index_list NOT valid!.\n");
+ return -EFAULT;
+ }
+ /* Find the numerically lowest first free index. */
+ for(i = 0; i < hvcs_index_count; i++) {
+ if (hvcs_index_list[i] == -1) {
+ hvcs_index_list[i] = 0;
+ return i;
+ }
+ }
+ return -1;
+}
+
+static int hvcs_probe(
+ struct vio_dev *dev,
+ const struct vio_device_id *id)
+{
+ struct hvcs_struct *hvcsd;
+ int index, rc;
+ int retval;
+
+ if (!dev || !id) {
+ printk(KERN_ERR "HVCS: probed with invalid parameter.\n");
+ return -EPERM;
+ }
+
+ /* Make sure we are properly initialized */
+ rc = hvcs_initialize();
+ if (rc) {
+ pr_err("HVCS: Failed to initialize core driver.\n");
+ return rc;
+ }
+
+ /* early to avoid cleanup on failure */
+ index = hvcs_get_index();
+ if (index < 0) {
+ return -EFAULT;
+ }
+
+ hvcsd = kzalloc(sizeof(*hvcsd), GFP_KERNEL);
+ if (!hvcsd)
+ return -ENODEV;
+
+ tty_port_init(&hvcsd->port);
+ hvcsd->port.ops = &hvcs_port_ops;
+ spin_lock_init(&hvcsd->lock);
+
+ hvcsd->vdev = dev;
+ dev_set_drvdata(&dev->dev, hvcsd);
+
+ hvcsd->index = index;
+
+ /* hvcsd->index = ++hvcs_struct_count; */
+ hvcsd->chars_in_buffer = 0;
+ hvcsd->todo_mask = 0;
+ hvcsd->connected = 0;
+
+ /*
+ * This will populate the hvcs_struct's partner info fields for the
+ * first time.
+ */
+ if (hvcs_get_pi(hvcsd)) {
+ printk(KERN_ERR "HVCS: Failed to fetch partner"
+ " info for vty-server@%X on device probe.\n",
+ hvcsd->vdev->unit_address);
+ }
+
+ /*
+ * If a user app opens a tty that corresponds to this vty-server before
+ * the hvcs_struct has been added to the devices list then the user app
+ * will get -ENODEV.
+ */
+ spin_lock(&hvcs_structs_lock);
+ list_add_tail(&(hvcsd->next), &hvcs_structs);
+ spin_unlock(&hvcs_structs_lock);
+
+ retval = sysfs_create_group(&dev->dev.kobj, &hvcs_attr_group);
+ if (retval) {
+ printk(KERN_ERR "HVCS: Can't create sysfs attrs for vty-server@%X\n",
+ hvcsd->vdev->unit_address);
+ return retval;
+ }
+
+ printk(KERN_INFO "HVCS: vty-server@%X added to the vio bus.\n", dev->unit_address);
+
+ /*
+ * DON'T enable interrupts here because there is no user to receive the
+ * data.
+ */
+ return 0;
+}
+
+static int hvcs_remove(struct vio_dev *dev)
+{
+ struct hvcs_struct *hvcsd = dev_get_drvdata(&dev->dev);
+ unsigned long flags;
+ struct tty_struct *tty;
+
+ if (!hvcsd)
+ return -ENODEV;
+
+ /* By this time the vty-server won't be getting any more interrupts */
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+
+ tty = hvcsd->port.tty;
+
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+ /*
+ * Let the last holder of this object cause it to be removed, which
+ * would probably be tty_hangup below.
+ */
+ tty_port_put(&hvcsd->port);
+
+ /*
+ * The hangup is a scheduled function which will auto chain call
+ * hvcs_hangup. The tty should always be valid at this time unless a
+ * simultaneous tty close already cleaned up the hvcs_struct.
+ */
+ if (tty)
+ tty_hangup(tty);
+
+ printk(KERN_INFO "HVCS: vty-server@%X removed from the"
+ " vio bus.\n", dev->unit_address);
+ return 0;
+};
+
+static struct vio_driver hvcs_vio_driver = {
+ .id_table = hvcs_driver_table,
+ .probe = hvcs_probe,
+ .remove = hvcs_remove,
+ .name = hvcs_driver_name,
+};
+
+/* Only called from hvcs_get_pi please */
+static void hvcs_set_pi(struct hvcs_partner_info *pi, struct hvcs_struct *hvcsd)
+{
+ hvcsd->p_unit_address = pi->unit_address;
+ hvcsd->p_partition_ID = pi->partition_ID;
+
+ /* copy the null-term char too */
+ strlcpy(&hvcsd->p_location_code[0],
+ &pi->location_code[0], sizeof(hvcsd->p_location_code));
+}
+
+/*
+ * Traverse the list and add the partner info that is found to the hvcs_struct
+ * struct entry. NOTE: At this time I know that partner info will return a
+ * single entry but in the future there may be multiple partner info entries per
+ * vty-server and you'll want to zero out that list and reset it. If for some
+ * reason you have an old version of this driver but there IS more than one
+ * partner info then hvcsd->p_* will hold the last partner info data from the
+ * firmware query. A good way to update this code would be to replace the three
+ * partner info fields in hvcs_struct with a list of hvcs_partner_info
+ * instances.
+ *
+ * This function must be called with the hvcsd->lock held.
+ */
+static int hvcs_get_pi(struct hvcs_struct *hvcsd)
+{
+ struct hvcs_partner_info *pi;
+ uint32_t unit_address = hvcsd->vdev->unit_address;
+ struct list_head head;
+ int retval;
+
+ spin_lock(&hvcs_pi_lock);
+ if (!hvcs_pi_buff) {
+ spin_unlock(&hvcs_pi_lock);
+ return -EFAULT;
+ }
+ retval = hvcs_get_partner_info(unit_address, &head, hvcs_pi_buff);
+ spin_unlock(&hvcs_pi_lock);
+ if (retval) {
+ printk(KERN_ERR "HVCS: Failed to fetch partner"
+ " info for vty-server@%x.\n", unit_address);
+ return retval;
+ }
+
+ /* nixes the values if the partner vty went away */
+ hvcsd->p_unit_address = 0;
+ hvcsd->p_partition_ID = 0;
+
+ list_for_each_entry(pi, &head, node)
+ hvcs_set_pi(pi, hvcsd);
+
+ hvcs_free_partner_info(&head);
+ return 0;
+}
+
+/*
+ * This function is executed by the driver "rescan" sysfs entry. It shouldn't
+ * be executed elsewhere, in order to prevent deadlock issues.
+ */
+static int hvcs_rescan_devices_list(void)
+{
+ struct hvcs_struct *hvcsd;
+ unsigned long flags;
+
+ spin_lock(&hvcs_structs_lock);
+
+ list_for_each_entry(hvcsd, &hvcs_structs, next) {
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ hvcs_get_pi(hvcsd);
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ }
+
+ spin_unlock(&hvcs_structs_lock);
+
+ return 0;
+}
+
+/*
+ * Farm this off into its own function because it could be more complex once
+ * multiple partners support is added. This function should be called with
+ * the hvcsd->lock held.
+ */
+static int hvcs_has_pi(struct hvcs_struct *hvcsd)
+{
+ if ((!hvcsd->p_unit_address) || (!hvcsd->p_partition_ID))
+ return 0;
+ return 1;
+}
+
+/*
+ * NOTE: It is possible that the super admin removed a partner vty and then
+ * added a different vty as the new partner.
+ *
+ * This function must be called with the hvcsd->lock held.
+ */
+static int hvcs_partner_connect(struct hvcs_struct *hvcsd)
+{
+ int retval;
+ unsigned int unit_address = hvcsd->vdev->unit_address;
+
+ /*
+ * If there wasn't any pi when the device was added it doesn't meant
+ * there isn't any now. This driver isn't notified when a new partner
+ * vty is added to a vty-server so we discover changes on our own.
+ * Please see comments in hvcs_register_connection() for justification
+ * of this bizarre code.
+ */
+ retval = hvcs_register_connection(unit_address,
+ hvcsd->p_partition_ID,
+ hvcsd->p_unit_address);
+ if (!retval) {
+ hvcsd->connected = 1;
+ return 0;
+ } else if (retval != -EINVAL)
+ return retval;
+
+ /*
+ * As per the spec re-get the pi and try again if -EINVAL after the
+ * first connection attempt.
+ */
+ if (hvcs_get_pi(hvcsd))
+ return -ENOMEM;
+
+ if (!hvcs_has_pi(hvcsd))
+ return -ENODEV;
+
+ retval = hvcs_register_connection(unit_address,
+ hvcsd->p_partition_ID,
+ hvcsd->p_unit_address);
+ if (retval != -EINVAL) {
+ hvcsd->connected = 1;
+ return retval;
+ }
+
+ /*
+ * EBUSY is the most likely scenario though the vty could have been
+ * removed or there really could be an hcall error due to the parameter
+ * data but thanks to ambiguous firmware return codes we can't really
+ * tell.
+ */
+ printk(KERN_INFO "HVCS: vty-server or partner"
+ " vty is busy. Try again later.\n");
+ return -EBUSY;
+}
+
+/* This function must be called with the hvcsd->lock held */
+static void hvcs_partner_free(struct hvcs_struct *hvcsd)
+{
+ int retval;
+ do {
+ retval = hvcs_free_connection(hvcsd->vdev->unit_address);
+ } while (retval == -EBUSY);
+ hvcsd->connected = 0;
+}
+
+/* This helper function must be called WITHOUT the hvcsd->lock held */
+static int hvcs_enable_device(struct hvcs_struct *hvcsd, uint32_t unit_address,
+ unsigned int irq, struct vio_dev *vdev)
+{
+ unsigned long flags;
+ int rc;
+
+ /*
+ * It is possible that the vty-server was removed between the time that
+ * the conn was registered and now.
+ */
+ rc = request_irq(irq, &hvcs_handle_interrupt, 0, "ibmhvcs", hvcsd);
+ if (!rc) {
+ /*
+ * It is possible the vty-server was removed after the irq was
+ * requested but before we have time to enable interrupts.
+ */
+ if (vio_enable_interrupts(vdev) == H_SUCCESS)
+ return 0;
+ else {
+ printk(KERN_ERR "HVCS: int enable failed for"
+ " vty-server@%X.\n", unit_address);
+ free_irq(irq, hvcsd);
+ }
+ } else
+ printk(KERN_ERR "HVCS: irq req failed for"
+ " vty-server@%X.\n", unit_address);
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ hvcs_partner_free(hvcsd);
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+ return rc;
+
+}
+
+/*
+ * This always increments the kref ref count if the call is successful.
+ * Please remember to dec when you are done with the instance.
+ *
+ * NOTICE: Do NOT hold either the hvcs_struct.lock or hvcs_structs_lock when
+ * calling this function or you will get deadlock.
+ */
+static struct hvcs_struct *hvcs_get_by_index(int index)
+{
+ struct hvcs_struct *hvcsd;
+ unsigned long flags;
+
+ spin_lock(&hvcs_structs_lock);
+ list_for_each_entry(hvcsd, &hvcs_structs, next) {
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ if (hvcsd->index == index) {
+ tty_port_get(&hvcsd->port);
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ spin_unlock(&hvcs_structs_lock);
+ return hvcsd;
+ }
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ }
+ spin_unlock(&hvcs_structs_lock);
+
+ return NULL;
+}
+
+static int hvcs_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+ struct hvcs_struct *hvcsd;
+ struct vio_dev *vdev;
+ unsigned long unit_address, flags;
+ unsigned int irq;
+ int retval;
+
+ /*
+ * Is there a vty-server that shares the same index?
+ * This function increments the kref index.
+ */
+ hvcsd = hvcs_get_by_index(tty->index);
+ if (!hvcsd) {
+ printk(KERN_WARNING "HVCS: open failed, no device associated"
+ " with tty->index %d.\n", tty->index);
+ return -ENODEV;
+ }
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+
+ if (hvcsd->connected == 0) {
+ retval = hvcs_partner_connect(hvcsd);
+ if (retval) {
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ printk(KERN_WARNING "HVCS: partner connect failed.\n");
+ goto err_put;
+ }
+ }
+
+ hvcsd->port.count = 0;
+ hvcsd->port.tty = tty;
+ tty->driver_data = hvcsd;
+
+ memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN);
+
+ /*
+ * Save these in the spinlock for the enable operations that need them
+ * outside of the spinlock.
+ */
+ irq = hvcsd->vdev->irq;
+ vdev = hvcsd->vdev;
+ unit_address = hvcsd->vdev->unit_address;
+
+ hvcsd->todo_mask |= HVCS_SCHED_READ;
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+ /*
+ * This must be done outside of the spinlock because it requests irqs
+ * and will grab the spinlock and free the connection if it fails.
+ */
+ retval = hvcs_enable_device(hvcsd, unit_address, irq, vdev);
+ if (retval) {
+ printk(KERN_WARNING "HVCS: enable device failed.\n");
+ goto err_put;
+ }
+
+ retval = tty_port_install(&hvcsd->port, driver, tty);
+ if (retval)
+ goto err_irq;
+
+ return 0;
+err_irq:
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ vio_disable_interrupts(hvcsd->vdev);
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ free_irq(irq, hvcsd);
+err_put:
+ tty_port_put(&hvcsd->port);
+
+ return retval;
+}
+
+/*
+ * This is invoked via the tty_open interface when a user app connects to the
+ * /dev node.
+ */
+static int hvcs_open(struct tty_struct *tty, struct file *filp)
+{
+ struct hvcs_struct *hvcsd = tty->driver_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ hvcsd->port.count++;
+ hvcsd->todo_mask |= HVCS_SCHED_READ;
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+ hvcs_kick();
+
+ printk(KERN_INFO "HVCS: vty-server@%X connection opened.\n",
+ hvcsd->vdev->unit_address );
+
+ return 0;
+}
+
+static void hvcs_close(struct tty_struct *tty, struct file *filp)
+{
+ struct hvcs_struct *hvcsd;
+ unsigned long flags;
+ int irq;
+
+ /*
+ * Is someone trying to close the file associated with this device after
+ * we have hung up? If so tty->driver_data wouldn't be valid.
+ */
+ if (tty_hung_up_p(filp))
+ return;
+
+ /*
+ * No driver_data means that this close was probably issued after a
+ * failed hvcs_open by the tty layer's release_dev() api and we can just
+ * exit cleanly.
+ */
+ if (!tty->driver_data)
+ return;
+
+ hvcsd = tty->driver_data;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ if (--hvcsd->port.count == 0) {
+
+ vio_disable_interrupts(hvcsd->vdev);
+
+ /*
+ * NULL this early so that the kernel_thread doesn't try to
+ * execute any operations on the TTY even though it is obligated
+ * to deliver any pending I/O to the hypervisor.
+ */
+ hvcsd->port.tty = NULL;
+
+ irq = hvcsd->vdev->irq;
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+ tty_wait_until_sent(tty, HVCS_CLOSE_WAIT);
+
+ /*
+ * This line is important because it tells hvcs_open that this
+ * device needs to be re-configured the next time hvcs_open is
+ * called.
+ */
+ tty->driver_data = NULL;
+
+ free_irq(irq, hvcsd);
+ return;
+ } else if (hvcsd->port.count < 0) {
+ printk(KERN_ERR "HVCS: vty-server@%X open_count: %d is mismanaged.\n",
+ hvcsd->vdev->unit_address, hvcsd->port.count);
+ }
+
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+}
+
+static void hvcs_cleanup(struct tty_struct * tty)
+{
+ struct hvcs_struct *hvcsd = tty->driver_data;
+
+ tty_port_put(&hvcsd->port);
+}
+
+static void hvcs_hangup(struct tty_struct * tty)
+{
+ struct hvcs_struct *hvcsd = tty->driver_data;
+ unsigned long flags;
+ int temp_open_count;
+ int irq;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+ /* Preserve this so that we know how many kref refs to put */
+ temp_open_count = hvcsd->port.count;
+
+ /*
+ * Don't kref put inside the spinlock because the destruction
+ * callback may use the spinlock and it may get called before the
+ * spinlock has been released.
+ */
+ vio_disable_interrupts(hvcsd->vdev);
+
+ hvcsd->todo_mask = 0;
+
+ /* I don't think the tty needs the hvcs_struct pointer after a hangup */
+ tty->driver_data = NULL;
+ hvcsd->port.tty = NULL;
+
+ hvcsd->port.count = 0;
+
+ /* This will drop any buffered data on the floor which is OK in a hangup
+ * scenario. */
+ memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN);
+ hvcsd->chars_in_buffer = 0;
+
+ irq = hvcsd->vdev->irq;
+
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+ free_irq(irq, hvcsd);
+
+ /*
+ * We need to kref_put() for every open_count we have since the
+ * tty_hangup() function doesn't invoke a close per open connection on a
+ * non-console device.
+ */
+ while(temp_open_count) {
+ --temp_open_count;
+ /*
+ * The final put will trigger destruction of the hvcs_struct.
+ * NOTE: If this hangup was signaled from user space then the
+ * final put will never happen.
+ */
+ tty_port_put(&hvcsd->port);
+ }
+}
+
+/*
+ * NOTE: This is almost always from_user since user level apps interact with the
+ * /dev nodes. I'm trusting that if hvcs_write gets called and interrupted by
+ * hvcs_remove (which removes the target device and executes tty_hangup()) that
+ * tty_hangup will allow hvcs_write time to complete execution before it
+ * terminates our device.
+ */
+static int hvcs_write(struct tty_struct *tty,
+ const unsigned char *buf, int count)
+{
+ struct hvcs_struct *hvcsd = tty->driver_data;
+ unsigned int unit_address;
+ const unsigned char *charbuf;
+ unsigned long flags;
+ int total_sent = 0;
+ int tosend = 0;
+ int result = 0;
+
+ /*
+ * If they don't check the return code off of their open they may
+ * attempt this even if there is no connected device.
+ */
+ if (!hvcsd)
+ return -ENODEV;
+
+ /* Reasonable size to prevent user level flooding */
+ if (count > HVCS_MAX_FROM_USER) {
+ printk(KERN_WARNING "HVCS write: count being truncated to"
+ " HVCS_MAX_FROM_USER.\n");
+ count = HVCS_MAX_FROM_USER;
+ }
+
+ charbuf = buf;
+
+ spin_lock_irqsave(&hvcsd->lock, flags);
+
+ /*
+ * Somehow an open succeeded but the device was removed or the
+ * connection terminated between the vty-server and partner vty during
+ * the middle of a write operation? This is a crummy place to do this
+ * but we want to keep it all in the spinlock.
+ */
+ if (hvcsd->port.count <= 0) {
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+ return -ENODEV;
+ }
+
+ unit_address = hvcsd->vdev->unit_address;
+
+ while (count > 0) {
+ tosend = min(count, (HVCS_BUFF_LEN - hvcsd->chars_in_buffer));
+ /*
+ * No more space, this probably means that the last call to
+ * hvcs_write() didn't succeed and the buffer was filled up.
+ */
+ if (!tosend)
+ break;
+
+ memcpy(&hvcsd->buffer[hvcsd->chars_in_buffer],
+ &charbuf[total_sent],
+ tosend);
+
+ hvcsd->chars_in_buffer += tosend;
+
+ result = 0;
+
+ /*
+ * If this is true then we don't want to try writing to the
+ * hypervisor because that is the kernel_threads job now. We'll
+ * just add to the buffer.
+ */
+ if (!(hvcsd->todo_mask & HVCS_TRY_WRITE))
+ /* won't send partial writes */
+ result = hvc_put_chars(unit_address,
+ &hvcsd->buffer[0],
+ hvcsd->chars_in_buffer);
+
+ /*
+ * Since we know we have enough room in hvcsd->buffer for
+ * tosend we record that it was sent regardless of whether the
+ * hypervisor actually took it because we have it buffered.
+ */
+ total_sent+=tosend;
+ count-=tosend;
+ if (result == 0) {
+ hvcsd->todo_mask |= HVCS_TRY_WRITE;
+ hvcs_kick();
+ break;
+ }
+
+ hvcsd->chars_in_buffer = 0;
+ /*
+ * Test after the chars_in_buffer reset otherwise this could
+ * deadlock our writes if hvc_put_chars fails.
+ */
+ if (result < 0)
+ break;
+ }
+
+ spin_unlock_irqrestore(&hvcsd->lock, flags);
+
+ if (result == -1)
+ return -EIO;
+ else
+ return total_sent;
+}
+
+/*
+ * This is really asking how much can we guarantee that we can send or that we
+ * absolutely WILL BUFFER if we can't send it. This driver MUST honor the
+ * return value, hence the reason for hvcs_struct buffering.
+ */
+static int hvcs_write_room(struct tty_struct *tty)
+{
+ struct hvcs_struct *hvcsd = tty->driver_data;
+
+ if (!hvcsd || hvcsd->port.count <= 0)
+ return 0;
+
+ return HVCS_BUFF_LEN - hvcsd->chars_in_buffer;
+}
+
+static int hvcs_chars_in_buffer(struct tty_struct *tty)
+{
+ struct hvcs_struct *hvcsd = tty->driver_data;
+
+ return hvcsd->chars_in_buffer;
+}
+
+static const struct tty_operations hvcs_ops = {
+ .install = hvcs_install,
+ .open = hvcs_open,
+ .close = hvcs_close,
+ .cleanup = hvcs_cleanup,
+ .hangup = hvcs_hangup,
+ .write = hvcs_write,
+ .write_room = hvcs_write_room,
+ .chars_in_buffer = hvcs_chars_in_buffer,
+ .unthrottle = hvcs_unthrottle,
+ .throttle = hvcs_throttle,
+};
+
+static int hvcs_alloc_index_list(int n)
+{
+ int i;
+
+ hvcs_index_list = kmalloc_array(n, sizeof(hvcs_index_count),
+ GFP_KERNEL);
+ if (!hvcs_index_list)
+ return -ENOMEM;
+ hvcs_index_count = n;
+ for (i = 0; i < hvcs_index_count; i++)
+ hvcs_index_list[i] = -1;
+ return 0;
+}
+
+static void hvcs_free_index_list(void)
+{
+ /* Paranoia check to be thorough. */
+ kfree(hvcs_index_list);
+ hvcs_index_list = NULL;
+ hvcs_index_count = 0;
+}
+
+static int hvcs_initialize(void)
+{
+ int rc, num_ttys_to_alloc;
+
+ mutex_lock(&hvcs_init_mutex);
+ if (hvcs_task) {
+ mutex_unlock(&hvcs_init_mutex);
+ return 0;
+ }
+
+ /* Has the user specified an overload with an insmod param? */
+ if (hvcs_parm_num_devs <= 0 ||
+ (hvcs_parm_num_devs > HVCS_MAX_SERVER_ADAPTERS)) {
+ num_ttys_to_alloc = HVCS_DEFAULT_SERVER_ADAPTERS;
+ } else
+ num_ttys_to_alloc = hvcs_parm_num_devs;
+
+ hvcs_tty_driver = alloc_tty_driver(num_ttys_to_alloc);
+ if (!hvcs_tty_driver) {
+ mutex_unlock(&hvcs_init_mutex);
+ return -ENOMEM;
+ }
+
+ if (hvcs_alloc_index_list(num_ttys_to_alloc)) {
+ rc = -ENOMEM;
+ goto index_fail;
+ }
+
+ hvcs_tty_driver->driver_name = hvcs_driver_name;
+ hvcs_tty_driver->name = hvcs_device_node;
+
+ /*
+ * We'll let the system assign us a major number, indicated by leaving
+ * it blank.
+ */
+
+ hvcs_tty_driver->minor_start = HVCS_MINOR_START;
+ hvcs_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM;
+
+ /*
+ * We role our own so that we DONT ECHO. We can't echo because the
+ * device we are connecting to already echoes by default and this would
+ * throw us into a horrible recursive echo-echo-echo loop.
+ */
+ hvcs_tty_driver->init_termios = hvcs_tty_termios;
+ hvcs_tty_driver->flags = TTY_DRIVER_REAL_RAW;
+
+ tty_set_operations(hvcs_tty_driver, &hvcs_ops);
+
+ /*
+ * The following call will result in sysfs entries that denote the
+ * dynamically assigned major and minor numbers for our devices.
+ */
+ if (tty_register_driver(hvcs_tty_driver)) {
+ printk(KERN_ERR "HVCS: registration as a tty driver failed.\n");
+ rc = -EIO;
+ goto register_fail;
+ }
+
+ hvcs_pi_buff = (unsigned long *) __get_free_page(GFP_KERNEL);
+ if (!hvcs_pi_buff) {
+ rc = -ENOMEM;
+ goto buff_alloc_fail;
+ }
+
+ hvcs_task = kthread_run(khvcsd, NULL, "khvcsd");
+ if (IS_ERR(hvcs_task)) {
+ printk(KERN_ERR "HVCS: khvcsd creation failed.\n");
+ rc = -EIO;
+ goto kthread_fail;
+ }
+ mutex_unlock(&hvcs_init_mutex);
+ return 0;
+
+kthread_fail:
+ free_page((unsigned long)hvcs_pi_buff);
+buff_alloc_fail:
+ tty_unregister_driver(hvcs_tty_driver);
+register_fail:
+ hvcs_free_index_list();
+index_fail:
+ put_tty_driver(hvcs_tty_driver);
+ hvcs_tty_driver = NULL;
+ mutex_unlock(&hvcs_init_mutex);
+ return rc;
+}
+
+static int __init hvcs_module_init(void)
+{
+ int rc = vio_register_driver(&hvcs_vio_driver);
+ if (rc) {
+ printk(KERN_ERR "HVCS: can't register vio driver\n");
+ return rc;
+ }
+
+ pr_info("HVCS: Driver registered.\n");
+
+ /* This needs to be done AFTER the vio_register_driver() call or else
+ * the kobjects won't be initialized properly.
+ */
+ rc = driver_create_file(&(hvcs_vio_driver.driver), &driver_attr_rescan);
+ if (rc)
+ pr_warn("HVCS: Failed to create rescan file (err %d)\n", rc);
+
+ return 0;
+}
+
+static void __exit hvcs_module_exit(void)
+{
+ /*
+ * This driver receives hvcs_remove callbacks for each device upon
+ * module removal.
+ */
+ vio_unregister_driver(&hvcs_vio_driver);
+ if (!hvcs_task)
+ return;
+
+ /*
+ * This synchronous operation will wake the khvcsd kthread if it is
+ * asleep and will return when khvcsd has terminated.
+ */
+ kthread_stop(hvcs_task);
+
+ spin_lock(&hvcs_pi_lock);
+ free_page((unsigned long)hvcs_pi_buff);
+ hvcs_pi_buff = NULL;
+ spin_unlock(&hvcs_pi_lock);
+
+ driver_remove_file(&hvcs_vio_driver.driver, &driver_attr_rescan);
+
+ tty_unregister_driver(hvcs_tty_driver);
+
+ hvcs_free_index_list();
+
+ put_tty_driver(hvcs_tty_driver);
+
+ printk(KERN_INFO "HVCS: driver module removed.\n");
+}
+
+module_init(hvcs_module_init);
+module_exit(hvcs_module_exit);
diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c
new file mode 100644
index 0000000..66f95f7
--- /dev/null
+++ b/drivers/tty/hvc/hvsi.c
@@ -0,0 +1,1210 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2004 Hollis Blanchard <hollisb@us.ibm.com>, IBM
+ */
+
+/* Host Virtual Serial Interface (HVSI) is a protocol between the hosted OS
+ * and the service processor on IBM pSeries servers. On these servers, there
+ * are no serial ports under the OS's control, and sometimes there is no other
+ * console available either. However, the service processor has two standard
+ * serial ports, so this over-complicated protocol allows the OS to control
+ * those ports by proxy.
+ *
+ * Besides data, the procotol supports the reading/writing of the serial
+ * port's DTR line, and the reading of the CD line. This is to allow the OS to
+ * control a modem attached to the service processor's serial port. Note that
+ * the OS cannot change the speed of the port through this protocol.
+ */
+
+#undef DEBUG
+
+#include <linux/console.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/major.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <asm/hvcall.h>
+#include <asm/hvconsole.h>
+#include <asm/prom.h>
+#include <linux/uaccess.h>
+#include <asm/vio.h>
+#include <asm/param.h>
+#include <asm/hvsi.h>
+
+#define HVSI_MAJOR 229
+#define HVSI_MINOR 128
+#define MAX_NR_HVSI_CONSOLES 4
+
+#define HVSI_TIMEOUT (5*HZ)
+#define HVSI_VERSION 1
+#define HVSI_MAX_PACKET 256
+#define HVSI_MAX_READ 16
+#define HVSI_MAX_OUTGOING_DATA 12
+#define N_OUTBUF 12
+
+/*
+ * we pass data via two 8-byte registers, so we would like our char arrays
+ * properly aligned for those loads.
+ */
+#define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
+
+struct hvsi_struct {
+ struct tty_port port;
+ struct delayed_work writer;
+ struct work_struct handshaker;
+ wait_queue_head_t emptyq; /* woken when outbuf is emptied */
+ wait_queue_head_t stateq; /* woken when HVSI state changes */
+ spinlock_t lock;
+ int index;
+ uint8_t throttle_buf[128];
+ uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */
+ /* inbuf is for packet reassembly. leave a little room for leftovers. */
+ uint8_t inbuf[HVSI_MAX_PACKET + HVSI_MAX_READ];
+ uint8_t *inbuf_end;
+ int n_throttle;
+ int n_outbuf;
+ uint32_t vtermno;
+ uint32_t virq;
+ atomic_t seqno; /* HVSI packet sequence number */
+ uint16_t mctrl;
+ uint8_t state; /* HVSI protocol state */
+ uint8_t flags;
+#ifdef CONFIG_MAGIC_SYSRQ
+ uint8_t sysrq;
+#endif /* CONFIG_MAGIC_SYSRQ */
+};
+static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES];
+
+static struct tty_driver *hvsi_driver;
+static int hvsi_count;
+static int (*hvsi_wait)(struct hvsi_struct *hp, int state);
+
+enum HVSI_PROTOCOL_STATE {
+ HVSI_CLOSED,
+ HVSI_WAIT_FOR_VER_RESPONSE,
+ HVSI_WAIT_FOR_VER_QUERY,
+ HVSI_OPEN,
+ HVSI_WAIT_FOR_MCTRL_RESPONSE,
+ HVSI_FSP_DIED,
+};
+#define HVSI_CONSOLE 0x1
+
+static inline int is_console(struct hvsi_struct *hp)
+{
+ return hp->flags & HVSI_CONSOLE;
+}
+
+static inline int is_open(struct hvsi_struct *hp)
+{
+ /* if we're waiting for an mctrl then we're already open */
+ return (hp->state == HVSI_OPEN)
+ || (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE);
+}
+
+static inline void print_state(struct hvsi_struct *hp)
+{
+#ifdef DEBUG
+ static const char *state_names[] = {
+ "HVSI_CLOSED",
+ "HVSI_WAIT_FOR_VER_RESPONSE",
+ "HVSI_WAIT_FOR_VER_QUERY",
+ "HVSI_OPEN",
+ "HVSI_WAIT_FOR_MCTRL_RESPONSE",
+ "HVSI_FSP_DIED",
+ };
+ const char *name = (hp->state < ARRAY_SIZE(state_names))
+ ? state_names[hp->state] : "UNKNOWN";
+
+ pr_debug("hvsi%i: state = %s\n", hp->index, name);
+#endif /* DEBUG */
+}
+
+static inline void __set_state(struct hvsi_struct *hp, int state)
+{
+ hp->state = state;
+ print_state(hp);
+ wake_up_all(&hp->stateq);
+}
+
+static inline void set_state(struct hvsi_struct *hp, int state)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&hp->lock, flags);
+ __set_state(hp, state);
+ spin_unlock_irqrestore(&hp->lock, flags);
+}
+
+static inline int len_packet(const uint8_t *packet)
+{
+ return (int)((struct hvsi_header *)packet)->len;
+}
+
+static inline int is_header(const uint8_t *packet)
+{
+ struct hvsi_header *header = (struct hvsi_header *)packet;
+ return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER;
+}
+
+static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet)
+{
+ if (hp->inbuf_end < packet + sizeof(struct hvsi_header))
+ return 0; /* don't even have the packet header */
+
+ if (hp->inbuf_end < (packet + len_packet(packet)))
+ return 0; /* don't have the rest of the packet */
+
+ return 1;
+}
+
+/* shift remaining bytes in packetbuf down */
+static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to)
+{
+ int remaining = (int)(hp->inbuf_end - read_to);
+
+ pr_debug("%s: %i chars remain\n", __func__, remaining);
+
+ if (read_to != hp->inbuf)
+ memmove(hp->inbuf, read_to, remaining);
+
+ hp->inbuf_end = hp->inbuf + remaining;
+}
+
+#ifdef DEBUG
+#define dbg_dump_packet(packet) dump_packet(packet)
+#define dbg_dump_hex(data, len) dump_hex(data, len)
+#else
+#define dbg_dump_packet(packet) do { } while (0)
+#define dbg_dump_hex(data, len) do { } while (0)
+#endif
+
+static void dump_hex(const uint8_t *data, int len)
+{
+ int i;
+
+ printk(" ");
+ for (i=0; i < len; i++)
+ printk("%.2x", data[i]);
+
+ printk("\n ");
+ for (i=0; i < len; i++) {
+ if (isprint(data[i]))
+ printk("%c", data[i]);
+ else
+ printk(".");
+ }
+ printk("\n");
+}
+
+static void dump_packet(uint8_t *packet)
+{
+ struct hvsi_header *header = (struct hvsi_header *)packet;
+
+ printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len,
+ header->seqno);
+
+ dump_hex(packet, header->len);
+}
+
+static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
+{
+ unsigned long got;
+
+ got = hvc_get_chars(hp->vtermno, buf, count);
+
+ return got;
+}
+
+static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
+ struct tty_struct *tty, struct hvsi_struct **to_handshake)
+{
+ struct hvsi_control *header = (struct hvsi_control *)packet;
+
+ switch (be16_to_cpu(header->verb)) {
+ case VSV_MODEM_CTL_UPDATE:
+ if ((be32_to_cpu(header->word) & HVSI_TSCD) == 0) {
+ /* CD went away; no more connection */
+ pr_debug("hvsi%i: CD dropped\n", hp->index);
+ hp->mctrl &= TIOCM_CD;
+ if (tty && !C_CLOCAL(tty))
+ tty_hangup(tty);
+ }
+ break;
+ case VSV_CLOSE_PROTOCOL:
+ pr_debug("hvsi%i: service processor came back\n", hp->index);
+ if (hp->state != HVSI_CLOSED) {
+ *to_handshake = hp;
+ }
+ break;
+ default:
+ printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ",
+ hp->index);
+ dump_packet(packet);
+ break;
+ }
+}
+
+static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
+{
+ struct hvsi_query_response *resp = (struct hvsi_query_response *)packet;
+ uint32_t mctrl_word;
+
+ switch (hp->state) {
+ case HVSI_WAIT_FOR_VER_RESPONSE:
+ __set_state(hp, HVSI_WAIT_FOR_VER_QUERY);
+ break;
+ case HVSI_WAIT_FOR_MCTRL_RESPONSE:
+ hp->mctrl = 0;
+ mctrl_word = be32_to_cpu(resp->u.mctrl_word);
+ if (mctrl_word & HVSI_TSDTR)
+ hp->mctrl |= TIOCM_DTR;
+ if (mctrl_word & HVSI_TSCD)
+ hp->mctrl |= TIOCM_CD;
+ __set_state(hp, HVSI_OPEN);
+ break;
+ default:
+ printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index);
+ dump_packet(packet);
+ break;
+ }
+}
+
+/* respond to service processor's version query */
+static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno)
+{
+ struct hvsi_query_response packet __ALIGNED__;
+ int wrote;
+
+ packet.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER;
+ packet.hdr.len = sizeof(struct hvsi_query_response);
+ packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+ packet.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER);
+ packet.u.version = HVSI_VERSION;
+ packet.query_seqno = cpu_to_be16(query_seqno+1);
+
+ pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
+ dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
+
+ wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
+ if (wrote != packet.hdr.len) {
+ printk(KERN_ERR "hvsi%i: couldn't send query response!\n",
+ hp->index);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
+{
+ struct hvsi_query *query = (struct hvsi_query *)packet;
+
+ switch (hp->state) {
+ case HVSI_WAIT_FOR_VER_QUERY:
+ hvsi_version_respond(hp, be16_to_cpu(query->hdr.seqno));
+ __set_state(hp, HVSI_OPEN);
+ break;
+ default:
+ printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index);
+ dump_packet(packet);
+ break;
+ }
+}
+
+static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
+{
+ int i;
+
+ for (i=0; i < len; i++) {
+ char c = buf[i];
+#ifdef CONFIG_MAGIC_SYSRQ
+ if (c == '\0') {
+ hp->sysrq = 1;
+ continue;
+ } else if (hp->sysrq) {
+ handle_sysrq(c);
+ hp->sysrq = 0;
+ continue;
+ }
+#endif /* CONFIG_MAGIC_SYSRQ */
+ tty_insert_flip_char(&hp->port, c, 0);
+ }
+}
+
+/*
+ * We could get 252 bytes of data at once here. But the tty layer only
+ * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow
+ * it. Accordingly we won't send more than 128 bytes at a time to the flip
+ * buffer, which will give the tty buffer a chance to throttle us. Should the
+ * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be
+ * revisited.
+ */
+#define TTY_THRESHOLD_THROTTLE 128
+static bool hvsi_recv_data(struct hvsi_struct *hp, const uint8_t *packet)
+{
+ const struct hvsi_header *header = (const struct hvsi_header *)packet;
+ const uint8_t *data = packet + sizeof(struct hvsi_header);
+ int datalen = header->len - sizeof(struct hvsi_header);
+ int overflow = datalen - TTY_THRESHOLD_THROTTLE;
+
+ pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data);
+
+ if (datalen == 0)
+ return false;
+
+ if (overflow > 0) {
+ pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__);
+ datalen = TTY_THRESHOLD_THROTTLE;
+ }
+
+ hvsi_insert_chars(hp, data, datalen);
+
+ if (overflow > 0) {
+ /*
+ * we still have more data to deliver, so we need to save off the
+ * overflow and send it later
+ */
+ pr_debug("%s: deferring overflow\n", __func__);
+ memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow);
+ hp->n_throttle = overflow;
+ }
+
+ return true;
+}
+
+/*
+ * Returns true/false indicating data successfully read from hypervisor.
+ * Used both to get packets for tty connections and to advance the state
+ * machine during console handshaking (in which case tty = NULL and we ignore
+ * incoming data).
+ */
+static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct *tty,
+ struct hvsi_struct **handshake)
+{
+ uint8_t *packet = hp->inbuf;
+ int chunklen;
+ bool flip = false;
+
+ *handshake = NULL;
+
+ chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ);
+ if (chunklen == 0) {
+ pr_debug("%s: 0-length read\n", __func__);
+ return 0;
+ }
+
+ pr_debug("%s: got %i bytes\n", __func__, chunklen);
+ dbg_dump_hex(hp->inbuf_end, chunklen);
+
+ hp->inbuf_end += chunklen;
+
+ /* handle all completed packets */
+ while ((packet < hp->inbuf_end) && got_packet(hp, packet)) {
+ struct hvsi_header *header = (struct hvsi_header *)packet;
+
+ if (!is_header(packet)) {
+ printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index);
+ /* skip bytes until we find a header or run out of data */
+ while ((packet < hp->inbuf_end) && (!is_header(packet)))
+ packet++;
+ continue;
+ }
+
+ pr_debug("%s: handling %i-byte packet\n", __func__,
+ len_packet(packet));
+ dbg_dump_packet(packet);
+
+ switch (header->type) {
+ case VS_DATA_PACKET_HEADER:
+ if (!is_open(hp))
+ break;
+ flip = hvsi_recv_data(hp, packet);
+ break;
+ case VS_CONTROL_PACKET_HEADER:
+ hvsi_recv_control(hp, packet, tty, handshake);
+ break;
+ case VS_QUERY_RESPONSE_PACKET_HEADER:
+ hvsi_recv_response(hp, packet);
+ break;
+ case VS_QUERY_PACKET_HEADER:
+ hvsi_recv_query(hp, packet);
+ break;
+ default:
+ printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n",
+ hp->index, header->type);
+ dump_packet(packet);
+ break;
+ }
+
+ packet += len_packet(packet);
+
+ if (*handshake) {
+ pr_debug("%s: handshake\n", __func__);
+ break;
+ }
+ }
+
+ compact_inbuf(hp, packet);
+
+ if (flip)
+ tty_flip_buffer_push(&hp->port);
+
+ return 1;
+}
+
+static void hvsi_send_overflow(struct hvsi_struct *hp)
+{
+ pr_debug("%s: delivering %i bytes overflow\n", __func__,
+ hp->n_throttle);
+
+ hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle);
+ hp->n_throttle = 0;
+}
+
+/*
+ * must get all pending data because we only get an irq on empty->non-empty
+ * transition
+ */
+static irqreturn_t hvsi_interrupt(int irq, void *arg)
+{
+ struct hvsi_struct *hp = (struct hvsi_struct *)arg;
+ struct hvsi_struct *handshake;
+ struct tty_struct *tty;
+ unsigned long flags;
+ int again = 1;
+
+ pr_debug("%s\n", __func__);
+
+ tty = tty_port_tty_get(&hp->port);
+
+ while (again) {
+ spin_lock_irqsave(&hp->lock, flags);
+ again = hvsi_load_chunk(hp, tty, &handshake);
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ if (handshake) {
+ pr_debug("hvsi%i: attempting re-handshake\n", handshake->index);
+ schedule_work(&handshake->handshaker);
+ }
+ }
+
+ spin_lock_irqsave(&hp->lock, flags);
+ if (tty && hp->n_throttle && !tty_throttled(tty)) {
+ /* we weren't hung up and we weren't throttled, so we can
+ * deliver the rest now */
+ hvsi_send_overflow(hp);
+ tty_flip_buffer_push(&hp->port);
+ }
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ tty_kref_put(tty);
+
+ return IRQ_HANDLED;
+}
+
+/* for boot console, before the irq handler is running */
+static int __init poll_for_state(struct hvsi_struct *hp, int state)
+{
+ unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
+
+ for (;;) {
+ hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */
+
+ if (hp->state == state)
+ return 0;
+
+ mdelay(5);
+ if (time_after(jiffies, end_jiffies))
+ return -EIO;
+ }
+}
+
+/* wait for irq handler to change our state */
+static int wait_for_state(struct hvsi_struct *hp, int state)
+{
+ int ret = 0;
+
+ if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT))
+ ret = -EIO;
+
+ return ret;
+}
+
+static int hvsi_query(struct hvsi_struct *hp, uint16_t verb)
+{
+ struct hvsi_query packet __ALIGNED__;
+ int wrote;
+
+ packet.hdr.type = VS_QUERY_PACKET_HEADER;
+ packet.hdr.len = sizeof(struct hvsi_query);
+ packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+ packet.verb = cpu_to_be16(verb);
+
+ pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
+ dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
+
+ wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
+ if (wrote != packet.hdr.len) {
+ printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index,
+ wrote);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int hvsi_get_mctrl(struct hvsi_struct *hp)
+{
+ int ret;
+
+ set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE);
+ hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS);
+
+ ret = hvsi_wait(hp, HVSI_OPEN);
+ if (ret < 0) {
+ printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index);
+ set_state(hp, HVSI_OPEN);
+ return ret;
+ }
+
+ pr_debug("%s: mctrl 0x%x\n", __func__, hp->mctrl);
+
+ return 0;
+}
+
+/* note that we can only set DTR */
+static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl)
+{
+ struct hvsi_control packet __ALIGNED__;
+ int wrote;
+
+ packet.hdr.type = VS_CONTROL_PACKET_HEADER;
+ packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+ packet.hdr.len = sizeof(struct hvsi_control);
+ packet.verb = cpu_to_be16(VSV_SET_MODEM_CTL);
+ packet.mask = cpu_to_be32(HVSI_TSDTR);
+
+ if (mctrl & TIOCM_DTR)
+ packet.word = cpu_to_be32(HVSI_TSDTR);
+
+ pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
+ dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
+
+ wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
+ if (wrote != packet.hdr.len) {
+ printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static void hvsi_drain_input(struct hvsi_struct *hp)
+{
+ uint8_t buf[HVSI_MAX_READ] __ALIGNED__;
+ unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
+
+ while (time_before(end_jiffies, jiffies))
+ if (0 == hvsi_read(hp, buf, HVSI_MAX_READ))
+ break;
+}
+
+static int hvsi_handshake(struct hvsi_struct *hp)
+{
+ int ret;
+
+ /*
+ * We could have a CLOSE or other data waiting for us before we even try
+ * to open; try to throw it all away so we don't get confused. (CLOSE
+ * is the first message sent up the pipe when the FSP comes online. We
+ * need to distinguish between "it came up a while ago and we're the first
+ * user" and "it was just reset before it saw our handshake packet".)
+ */
+ hvsi_drain_input(hp);
+
+ set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE);
+ ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER);
+ if (ret < 0) {
+ printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index);
+ return ret;
+ }
+
+ ret = hvsi_wait(hp, HVSI_OPEN);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static void hvsi_handshaker(struct work_struct *work)
+{
+ struct hvsi_struct *hp =
+ container_of(work, struct hvsi_struct, handshaker);
+
+ if (hvsi_handshake(hp) >= 0)
+ return;
+
+ printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index);
+ if (is_console(hp)) {
+ /*
+ * ttys will re-attempt the handshake via hvsi_open, but
+ * the console will not.
+ */
+ printk(KERN_ERR "hvsi%i: lost console!\n", hp->index);
+ }
+}
+
+static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count)
+{
+ struct hvsi_data packet __ALIGNED__;
+ int ret;
+
+ BUG_ON(count > HVSI_MAX_OUTGOING_DATA);
+
+ packet.hdr.type = VS_DATA_PACKET_HEADER;
+ packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+ packet.hdr.len = count + sizeof(struct hvsi_header);
+ memcpy(&packet.data, buf, count);
+
+ ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
+ if (ret == packet.hdr.len) {
+ /* return the number of chars written, not the packet length */
+ return count;
+ }
+ return ret; /* return any errors */
+}
+
+static void hvsi_close_protocol(struct hvsi_struct *hp)
+{
+ struct hvsi_control packet __ALIGNED__;
+
+ packet.hdr.type = VS_CONTROL_PACKET_HEADER;
+ packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno));
+ packet.hdr.len = 6;
+ packet.verb = cpu_to_be16(VSV_CLOSE_PROTOCOL);
+
+ pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len);
+ dbg_dump_hex((uint8_t*)&packet, packet.hdr.len);
+
+ hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len);
+}
+
+static int hvsi_open(struct tty_struct *tty, struct file *filp)
+{
+ struct hvsi_struct *hp;
+ unsigned long flags;
+ int ret;
+
+ pr_debug("%s\n", __func__);
+
+ hp = &hvsi_ports[tty->index];
+
+ tty->driver_data = hp;
+
+ mb();
+ if (hp->state == HVSI_FSP_DIED)
+ return -EIO;
+
+ tty_port_tty_set(&hp->port, tty);
+ spin_lock_irqsave(&hp->lock, flags);
+ hp->port.count++;
+ atomic_set(&hp->seqno, 0);
+ h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ if (is_console(hp))
+ return 0; /* this has already been handshaked as the console */
+
+ ret = hvsi_handshake(hp);
+ if (ret < 0) {
+ printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name);
+ return ret;
+ }
+
+ ret = hvsi_get_mctrl(hp);
+ if (ret < 0) {
+ printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name);
+ return ret;
+ }
+
+ ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
+ if (ret < 0) {
+ printk(KERN_ERR "%s: couldn't set DTR\n", tty->name);
+ return ret;
+ }
+
+ return 0;
+}
+
+/* wait for hvsi_write_worker to empty hp->outbuf */
+static void hvsi_flush_output(struct hvsi_struct *hp)
+{
+ wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT);
+
+ /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */
+ cancel_delayed_work_sync(&hp->writer);
+ flush_work(&hp->handshaker);
+
+ /*
+ * it's also possible that our timeout expired and hvsi_write_worker
+ * didn't manage to push outbuf. poof.
+ */
+ hp->n_outbuf = 0;
+}
+
+static void hvsi_close(struct tty_struct *tty, struct file *filp)
+{
+ struct hvsi_struct *hp = tty->driver_data;
+ unsigned long flags;
+
+ pr_debug("%s\n", __func__);
+
+ if (tty_hung_up_p(filp))
+ return;
+
+ spin_lock_irqsave(&hp->lock, flags);
+
+ if (--hp->port.count == 0) {
+ tty_port_tty_set(&hp->port, NULL);
+ hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */
+
+ /* only close down connection if it is not the console */
+ if (!is_console(hp)) {
+ h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */
+ __set_state(hp, HVSI_CLOSED);
+ /*
+ * any data delivered to the tty layer after this will be
+ * discarded (except for XON/XOFF)
+ */
+ tty->closing = 1;
+
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ /* let any existing irq handlers finish. no more will start. */
+ synchronize_irq(hp->virq);
+
+ /* hvsi_write_worker will re-schedule until outbuf is empty. */
+ hvsi_flush_output(hp);
+
+ /* tell FSP to stop sending data */
+ hvsi_close_protocol(hp);
+
+ /*
+ * drain anything FSP is still in the middle of sending, and let
+ * hvsi_handshake drain the rest on the next open.
+ */
+ hvsi_drain_input(hp);
+
+ spin_lock_irqsave(&hp->lock, flags);
+ }
+ } else if (hp->port.count < 0)
+ printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n",
+ hp - hvsi_ports, hp->port.count);
+
+ spin_unlock_irqrestore(&hp->lock, flags);
+}
+
+static void hvsi_hangup(struct tty_struct *tty)
+{
+ struct hvsi_struct *hp = tty->driver_data;
+ unsigned long flags;
+
+ pr_debug("%s\n", __func__);
+
+ tty_port_tty_set(&hp->port, NULL);
+
+ spin_lock_irqsave(&hp->lock, flags);
+ hp->port.count = 0;
+ hp->n_outbuf = 0;
+ spin_unlock_irqrestore(&hp->lock, flags);
+}
+
+/* called with hp->lock held */
+static void hvsi_push(struct hvsi_struct *hp)
+{
+ int n;
+
+ if (hp->n_outbuf <= 0)
+ return;
+
+ n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf);
+ if (n > 0) {
+ /* success */
+ pr_debug("%s: wrote %i chars\n", __func__, n);
+ hp->n_outbuf = 0;
+ } else if (n == -EIO) {
+ __set_state(hp, HVSI_FSP_DIED);
+ printk(KERN_ERR "hvsi%i: service processor died\n", hp->index);
+ }
+}
+
+/* hvsi_write_worker will keep rescheduling itself until outbuf is empty */
+static void hvsi_write_worker(struct work_struct *work)
+{
+ struct hvsi_struct *hp =
+ container_of(work, struct hvsi_struct, writer.work);
+ unsigned long flags;
+#ifdef DEBUG
+ static long start_j = 0;
+
+ if (start_j == 0)
+ start_j = jiffies;
+#endif /* DEBUG */
+
+ spin_lock_irqsave(&hp->lock, flags);
+
+ pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
+
+ if (!is_open(hp)) {
+ /*
+ * We could have a non-open connection if the service processor died
+ * while we were busily scheduling ourselves. In that case, it could
+ * be minutes before the service processor comes back, so only try
+ * again once a second.
+ */
+ schedule_delayed_work(&hp->writer, HZ);
+ goto out;
+ }
+
+ hvsi_push(hp);
+ if (hp->n_outbuf > 0)
+ schedule_delayed_work(&hp->writer, 10);
+ else {
+#ifdef DEBUG
+ pr_debug("%s: outbuf emptied after %li jiffies\n", __func__,
+ jiffies - start_j);
+ start_j = 0;
+#endif /* DEBUG */
+ wake_up_all(&hp->emptyq);
+ tty_port_tty_wakeup(&hp->port);
+ }
+
+out:
+ spin_unlock_irqrestore(&hp->lock, flags);
+}
+
+static int hvsi_write_room(struct tty_struct *tty)
+{
+ struct hvsi_struct *hp = tty->driver_data;
+
+ return N_OUTBUF - hp->n_outbuf;
+}
+
+static int hvsi_chars_in_buffer(struct tty_struct *tty)
+{
+ struct hvsi_struct *hp = tty->driver_data;
+
+ return hp->n_outbuf;
+}
+
+static int hvsi_write(struct tty_struct *tty,
+ const unsigned char *buf, int count)
+{
+ struct hvsi_struct *hp = tty->driver_data;
+ const char *source = buf;
+ unsigned long flags;
+ int total = 0;
+ int origcount = count;
+
+ spin_lock_irqsave(&hp->lock, flags);
+
+ pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
+
+ if (!is_open(hp)) {
+ /* we're either closing or not yet open; don't accept data */
+ pr_debug("%s: not open\n", __func__);
+ goto out;
+ }
+
+ /*
+ * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf
+ * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
+ * will see there is no room in outbuf and return.
+ */
+ while ((count > 0) && (hvsi_write_room(tty) > 0)) {
+ int chunksize = min(count, hvsi_write_room(tty));
+
+ BUG_ON(hp->n_outbuf < 0);
+ memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
+ hp->n_outbuf += chunksize;
+
+ total += chunksize;
+ source += chunksize;
+ count -= chunksize;
+ hvsi_push(hp);
+ }
+
+ if (hp->n_outbuf > 0) {
+ /*
+ * we weren't able to write it all to the hypervisor.
+ * schedule another push attempt.
+ */
+ schedule_delayed_work(&hp->writer, 10);
+ }
+
+out:
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ if (total != origcount)
+ pr_debug("%s: wanted %i, only wrote %i\n", __func__, origcount,
+ total);
+
+ return total;
+}
+
+/*
+ * I have never seen throttle or unthrottle called, so this little throttle
+ * buffering scheme may or may not work.
+ */
+static void hvsi_throttle(struct tty_struct *tty)
+{
+ struct hvsi_struct *hp = tty->driver_data;
+
+ pr_debug("%s\n", __func__);
+
+ h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE);
+}
+
+static void hvsi_unthrottle(struct tty_struct *tty)
+{
+ struct hvsi_struct *hp = tty->driver_data;
+ unsigned long flags;
+
+ pr_debug("%s\n", __func__);
+
+ spin_lock_irqsave(&hp->lock, flags);
+ if (hp->n_throttle) {
+ hvsi_send_overflow(hp);
+ tty_flip_buffer_push(&hp->port);
+ }
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+
+ h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
+}
+
+static int hvsi_tiocmget(struct tty_struct *tty)
+{
+ struct hvsi_struct *hp = tty->driver_data;
+
+ hvsi_get_mctrl(hp);
+ return hp->mctrl;
+}
+
+static int hvsi_tiocmset(struct tty_struct *tty,
+ unsigned int set, unsigned int clear)
+{
+ struct hvsi_struct *hp = tty->driver_data;
+ unsigned long flags;
+ uint16_t new_mctrl;
+
+ /* we can only alter DTR */
+ clear &= TIOCM_DTR;
+ set &= TIOCM_DTR;
+
+ spin_lock_irqsave(&hp->lock, flags);
+
+ new_mctrl = (hp->mctrl & ~clear) | set;
+
+ if (hp->mctrl != new_mctrl) {
+ hvsi_set_mctrl(hp, new_mctrl);
+ hp->mctrl = new_mctrl;
+ }
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ return 0;
+}
+
+
+static const struct tty_operations hvsi_ops = {
+ .open = hvsi_open,
+ .close = hvsi_close,
+ .write = hvsi_write,
+ .hangup = hvsi_hangup,
+ .write_room = hvsi_write_room,
+ .chars_in_buffer = hvsi_chars_in_buffer,
+ .throttle = hvsi_throttle,
+ .unthrottle = hvsi_unthrottle,
+ .tiocmget = hvsi_tiocmget,
+ .tiocmset = hvsi_tiocmset,
+};
+
+static int __init hvsi_init(void)
+{
+ int i;
+
+ hvsi_driver = alloc_tty_driver(hvsi_count);
+ if (!hvsi_driver)
+ return -ENOMEM;
+
+ hvsi_driver->driver_name = "hvsi";
+ hvsi_driver->name = "hvsi";
+ hvsi_driver->major = HVSI_MAJOR;
+ hvsi_driver->minor_start = HVSI_MINOR;
+ hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM;
+ hvsi_driver->init_termios = tty_std_termios;
+ hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
+ hvsi_driver->init_termios.c_ispeed = 9600;
+ hvsi_driver->init_termios.c_ospeed = 9600;
+ hvsi_driver->flags = TTY_DRIVER_REAL_RAW;
+ tty_set_operations(hvsi_driver, &hvsi_ops);
+
+ for (i=0; i < hvsi_count; i++) {
+ struct hvsi_struct *hp = &hvsi_ports[i];
+ int ret = 1;
+
+ tty_port_link_device(&hp->port, hvsi_driver, i);
+
+ ret = request_irq(hp->virq, hvsi_interrupt, 0, "hvsi", hp);
+ if (ret)
+ printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n",
+ hp->virq, ret);
+ }
+ hvsi_wait = wait_for_state; /* irqs active now */
+
+ if (tty_register_driver(hvsi_driver))
+ panic("Couldn't register hvsi console driver\n");
+
+ printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count);
+
+ return 0;
+}
+device_initcall(hvsi_init);
+
+/***** console (not tty) code: *****/
+
+static void hvsi_console_print(struct console *console, const char *buf,
+ unsigned int count)
+{
+ struct hvsi_struct *hp = &hvsi_ports[console->index];
+ char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__;
+ unsigned int i = 0, n = 0;
+ int ret, donecr = 0;
+
+ mb();
+ if (!is_open(hp))
+ return;
+
+ /*
+ * ugh, we have to translate LF -> CRLF ourselves, in place.
+ * copied from hvc_console.c:
+ */
+ while (count > 0 || i > 0) {
+ if (count > 0 && i < sizeof(c)) {
+ if (buf[n] == '\n' && !donecr) {
+ c[i++] = '\r';
+ donecr = 1;
+ } else {
+ c[i++] = buf[n++];
+ donecr = 0;
+ --count;
+ }
+ } else {
+ ret = hvsi_put_chars(hp, c, i);
+ if (ret < 0)
+ i = 0;
+ i -= ret;
+ }
+ }
+}
+
+static struct tty_driver *hvsi_console_device(struct console *console,
+ int *index)
+{
+ *index = console->index;
+ return hvsi_driver;
+}
+
+static int __init hvsi_console_setup(struct console *console, char *options)
+{
+ struct hvsi_struct *hp;
+ int ret;
+
+ if (console->index < 0 || console->index >= hvsi_count)
+ return -1;
+ hp = &hvsi_ports[console->index];
+
+ /* give the FSP a chance to change the baud rate when we re-open */
+ hvsi_close_protocol(hp);
+
+ ret = hvsi_handshake(hp);
+ if (ret < 0)
+ return ret;
+
+ ret = hvsi_get_mctrl(hp);
+ if (ret < 0)
+ return ret;
+
+ ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
+ if (ret < 0)
+ return ret;
+
+ hp->flags |= HVSI_CONSOLE;
+
+ return 0;
+}
+
+static struct console hvsi_console = {
+ .name = "hvsi",
+ .write = hvsi_console_print,
+ .device = hvsi_console_device,
+ .setup = hvsi_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+};
+
+static int __init hvsi_console_init(void)
+{
+ struct device_node *vty;
+
+ hvsi_wait = poll_for_state; /* no irqs yet; must poll */
+
+ /* search device tree for vty nodes */
+ for_each_compatible_node(vty, "serial", "hvterm-protocol") {
+ struct hvsi_struct *hp;
+ const __be32 *vtermno, *irq;
+
+ vtermno = of_get_property(vty, "reg", NULL);
+ irq = of_get_property(vty, "interrupts", NULL);
+ if (!vtermno || !irq)
+ continue;
+
+ if (hvsi_count >= MAX_NR_HVSI_CONSOLES) {
+ of_node_put(vty);
+ break;
+ }
+
+ hp = &hvsi_ports[hvsi_count];
+ INIT_DELAYED_WORK(&hp->writer, hvsi_write_worker);
+ INIT_WORK(&hp->handshaker, hvsi_handshaker);
+ init_waitqueue_head(&hp->emptyq);
+ init_waitqueue_head(&hp->stateq);
+ spin_lock_init(&hp->lock);
+ tty_port_init(&hp->port);
+ hp->index = hvsi_count;
+ hp->inbuf_end = hp->inbuf;
+ hp->state = HVSI_CLOSED;
+ hp->vtermno = be32_to_cpup(vtermno);
+ hp->virq = irq_create_mapping(NULL, be32_to_cpup(irq));
+ if (hp->virq == 0) {
+ printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
+ __func__, be32_to_cpup(irq));
+ tty_port_destroy(&hp->port);
+ continue;
+ }
+
+ hvsi_count++;
+ }
+
+ if (hvsi_count)
+ register_console(&hvsi_console);
+ return 0;
+}
+console_initcall(hvsi_console_init);
diff --git a/drivers/tty/hvc/hvsi_lib.c b/drivers/tty/hvc/hvsi_lib.c
new file mode 100644
index 0000000..09289c8
--- /dev/null
+++ b/drivers/tty/hvc/hvsi_lib.c
@@ -0,0 +1,424 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/console.h>
+#include <asm/hvsi.h>
+
+#include "hvc_console.h"
+
+static int hvsi_send_packet(struct hvsi_priv *pv, struct hvsi_header *packet)
+{
+ packet->seqno = cpu_to_be16(atomic_inc_return(&pv->seqno));
+
+ /* Assumes that always succeeds, works in practice */
+ return pv->put_chars(pv->termno, (char *)packet, packet->len);
+}
+
+static void hvsi_start_handshake(struct hvsi_priv *pv)
+{
+ struct hvsi_query q;
+
+ /* Reset state */
+ pv->established = 0;
+ atomic_set(&pv->seqno, 0);
+
+ pr_devel("HVSI@%x: Handshaking started\n", pv->termno);
+
+ /* Send version query */
+ q.hdr.type = VS_QUERY_PACKET_HEADER;
+ q.hdr.len = sizeof(struct hvsi_query);
+ q.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER);
+ hvsi_send_packet(pv, &q.hdr);
+}
+
+static int hvsi_send_close(struct hvsi_priv *pv)
+{
+ struct hvsi_control ctrl;
+
+ pv->established = 0;
+
+ ctrl.hdr.type = VS_CONTROL_PACKET_HEADER;
+ ctrl.hdr.len = sizeof(struct hvsi_control);
+ ctrl.verb = cpu_to_be16(VSV_CLOSE_PROTOCOL);
+ return hvsi_send_packet(pv, &ctrl.hdr);
+}
+
+static void hvsi_cd_change(struct hvsi_priv *pv, int cd)
+{
+ if (cd)
+ pv->mctrl |= TIOCM_CD;
+ else {
+ pv->mctrl &= ~TIOCM_CD;
+
+ /* We copy the existing hvsi driver semantics
+ * here which are to trigger a hangup when
+ * we get a carrier loss.
+ * Closing our connection to the server will
+ * do just that.
+ */
+ if (!pv->is_console && pv->opened) {
+ pr_devel("HVSI@%x Carrier lost, hanging up !\n",
+ pv->termno);
+ hvsi_send_close(pv);
+ }
+ }
+}
+
+static void hvsi_got_control(struct hvsi_priv *pv)
+{
+ struct hvsi_control *pkt = (struct hvsi_control *)pv->inbuf;
+
+ switch (be16_to_cpu(pkt->verb)) {
+ case VSV_CLOSE_PROTOCOL:
+ /* We restart the handshaking */
+ hvsi_start_handshake(pv);
+ break;
+ case VSV_MODEM_CTL_UPDATE:
+ /* Transition of carrier detect */
+ hvsi_cd_change(pv, be32_to_cpu(pkt->word) & HVSI_TSCD);
+ break;
+ }
+}
+
+static void hvsi_got_query(struct hvsi_priv *pv)
+{
+ struct hvsi_query *pkt = (struct hvsi_query *)pv->inbuf;
+ struct hvsi_query_response r;
+
+ /* We only handle version queries */
+ if (be16_to_cpu(pkt->verb) != VSV_SEND_VERSION_NUMBER)
+ return;
+
+ pr_devel("HVSI@%x: Got version query, sending response...\n",
+ pv->termno);
+
+ /* Send version response */
+ r.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER;
+ r.hdr.len = sizeof(struct hvsi_query_response);
+ r.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER);
+ r.u.version = HVSI_VERSION;
+ r.query_seqno = pkt->hdr.seqno;
+ hvsi_send_packet(pv, &r.hdr);
+
+ /* Assume protocol is open now */
+ pv->established = 1;
+}
+
+static void hvsi_got_response(struct hvsi_priv *pv)
+{
+ struct hvsi_query_response *r =
+ (struct hvsi_query_response *)pv->inbuf;
+
+ switch(r->verb) {
+ case VSV_SEND_MODEM_CTL_STATUS:
+ hvsi_cd_change(pv, be32_to_cpu(r->u.mctrl_word) & HVSI_TSCD);
+ pv->mctrl_update = 1;
+ break;
+ }
+}
+
+static int hvsi_check_packet(struct hvsi_priv *pv)
+{
+ u8 len, type;
+
+ /* Check header validity. If it's invalid, we ditch
+ * the whole buffer and hope we eventually resync
+ */
+ if (pv->inbuf[0] < 0xfc) {
+ pv->inbuf_len = pv->inbuf_pktlen = 0;
+ return 0;
+ }
+ type = pv->inbuf[0];
+ len = pv->inbuf[1];
+
+ /* Packet incomplete ? */
+ if (pv->inbuf_len < len)
+ return 0;
+
+ pr_devel("HVSI@%x: Got packet type %x len %d bytes:\n",
+ pv->termno, type, len);
+
+ /* We have a packet, yay ! Handle it */
+ switch(type) {
+ case VS_DATA_PACKET_HEADER:
+ pv->inbuf_pktlen = len - 4;
+ pv->inbuf_cur = 4;
+ return 1;
+ case VS_CONTROL_PACKET_HEADER:
+ hvsi_got_control(pv);
+ break;
+ case VS_QUERY_PACKET_HEADER:
+ hvsi_got_query(pv);
+ break;
+ case VS_QUERY_RESPONSE_PACKET_HEADER:
+ hvsi_got_response(pv);
+ break;
+ }
+
+ /* Swallow packet and retry */
+ pv->inbuf_len -= len;
+ memmove(pv->inbuf, &pv->inbuf[len], pv->inbuf_len);
+ return 1;
+}
+
+static int hvsi_get_packet(struct hvsi_priv *pv)
+{
+ /* If we have room in the buffer, ask HV for more */
+ if (pv->inbuf_len < HVSI_INBUF_SIZE)
+ pv->inbuf_len += pv->get_chars(pv->termno,
+ &pv->inbuf[pv->inbuf_len],
+ HVSI_INBUF_SIZE - pv->inbuf_len);
+ /*
+ * If we have at least 4 bytes in the buffer, check for
+ * a full packet and retry
+ */
+ if (pv->inbuf_len >= 4)
+ return hvsi_check_packet(pv);
+ return 0;
+}
+
+int hvsilib_get_chars(struct hvsi_priv *pv, char *buf, int count)
+{
+ unsigned int tries, read = 0;
+
+ if (WARN_ON(!pv))
+ return -ENXIO;
+
+ /* If we aren't open, don't do anything in order to avoid races
+ * with connection establishment. The hvc core will call this
+ * before we have returned from notifier_add(), and we need to
+ * avoid multiple users playing with the receive buffer
+ */
+ if (!pv->opened)
+ return 0;
+
+ /* We try twice, once with what data we have and once more
+ * after we try to fetch some more from the hypervisor
+ */
+ for (tries = 1; count && tries < 2; tries++) {
+ /* Consume existing data packet */
+ if (pv->inbuf_pktlen) {
+ unsigned int l = min(count, (int)pv->inbuf_pktlen);
+ memcpy(&buf[read], &pv->inbuf[pv->inbuf_cur], l);
+ pv->inbuf_cur += l;
+ pv->inbuf_pktlen -= l;
+ count -= l;
+ read += l;
+ }
+ if (count == 0)
+ break;
+
+ /* Data packet fully consumed, move down remaning data */
+ if (pv->inbuf_cur) {
+ pv->inbuf_len -= pv->inbuf_cur;
+ memmove(pv->inbuf, &pv->inbuf[pv->inbuf_cur],
+ pv->inbuf_len);
+ pv->inbuf_cur = 0;
+ }
+
+ /* Try to get another packet */
+ if (hvsi_get_packet(pv))
+ tries--;
+ }
+ if (!pv->established) {
+ pr_devel("HVSI@%x: returning -EPIPE\n", pv->termno);
+ return -EPIPE;
+ }
+ return read;
+}
+
+int hvsilib_put_chars(struct hvsi_priv *pv, const char *buf, int count)
+{
+ struct hvsi_data dp;
+ int rc, adjcount = min(count, HVSI_MAX_OUTGOING_DATA);
+
+ if (WARN_ON(!pv))
+ return -ENODEV;
+
+ dp.hdr.type = VS_DATA_PACKET_HEADER;
+ dp.hdr.len = adjcount + sizeof(struct hvsi_header);
+ memcpy(dp.data, buf, adjcount);
+ rc = hvsi_send_packet(pv, &dp.hdr);
+ if (rc <= 0)
+ return rc;
+ return adjcount;
+}
+
+static void maybe_msleep(unsigned long ms)
+{
+ /* During early boot, IRQs are disabled, use mdelay */
+ if (irqs_disabled())
+ mdelay(ms);
+ else
+ msleep(ms);
+}
+
+int hvsilib_read_mctrl(struct hvsi_priv *pv)
+{
+ struct hvsi_query q;
+ int rc, timeout;
+
+ pr_devel("HVSI@%x: Querying modem control status...\n",
+ pv->termno);
+
+ pv->mctrl_update = 0;
+ q.hdr.type = VS_QUERY_PACKET_HEADER;
+ q.hdr.len = sizeof(struct hvsi_query);
+ q.verb = cpu_to_be16(VSV_SEND_MODEM_CTL_STATUS);
+ rc = hvsi_send_packet(pv, &q.hdr);
+ if (rc <= 0) {
+ pr_devel("HVSI@%x: Error %d...\n", pv->termno, rc);
+ return rc;
+ }
+
+ /* Try for up to 200ms */
+ for (timeout = 0; timeout < 20; timeout++) {
+ if (!pv->established)
+ return -ENXIO;
+ if (pv->mctrl_update)
+ return 0;
+ if (!hvsi_get_packet(pv))
+ maybe_msleep(10);
+ }
+ return -EIO;
+}
+
+int hvsilib_write_mctrl(struct hvsi_priv *pv, int dtr)
+{
+ struct hvsi_control ctrl;
+ unsigned short mctrl;
+
+ mctrl = pv->mctrl;
+ if (dtr)
+ mctrl |= TIOCM_DTR;
+ else
+ mctrl &= ~TIOCM_DTR;
+ if (mctrl == pv->mctrl)
+ return 0;
+ pv->mctrl = mctrl;
+
+ pr_devel("HVSI@%x: %s DTR...\n", pv->termno,
+ dtr ? "Setting" : "Clearing");
+
+ ctrl.hdr.type = VS_CONTROL_PACKET_HEADER,
+ ctrl.hdr.len = sizeof(struct hvsi_control);
+ ctrl.verb = cpu_to_be16(VSV_SET_MODEM_CTL);
+ ctrl.mask = cpu_to_be32(HVSI_TSDTR);
+ ctrl.word = cpu_to_be32(dtr ? HVSI_TSDTR : 0);
+ return hvsi_send_packet(pv, &ctrl.hdr);
+}
+
+void hvsilib_establish(struct hvsi_priv *pv)
+{
+ int timeout;
+
+ pr_devel("HVSI@%x: Establishing...\n", pv->termno);
+
+ /* Try for up to 200ms, there can be a packet to
+ * start the process waiting for us...
+ */
+ for (timeout = 0; timeout < 20; timeout++) {
+ if (pv->established)
+ goto established;
+ if (!hvsi_get_packet(pv))
+ maybe_msleep(10);
+ }
+
+ /* Failed, send a close connection packet just
+ * in case
+ */
+ pr_devel("HVSI@%x: ... sending close\n", pv->termno);
+
+ hvsi_send_close(pv);
+
+ /* Then restart handshake */
+
+ pr_devel("HVSI@%x: ... restarting handshake\n", pv->termno);
+
+ hvsi_start_handshake(pv);
+
+ pr_devel("HVSI@%x: ... waiting handshake\n", pv->termno);
+
+ /* Try for up to 400ms */
+ for (timeout = 0; timeout < 40; timeout++) {
+ if (pv->established)
+ goto established;
+ if (!hvsi_get_packet(pv))
+ maybe_msleep(10);
+ }
+
+ if (!pv->established) {
+ pr_devel("HVSI@%x: Timeout handshaking, giving up !\n",
+ pv->termno);
+ return;
+ }
+ established:
+ /* Query modem control lines */
+
+ pr_devel("HVSI@%x: ... established, reading mctrl\n", pv->termno);
+
+ hvsilib_read_mctrl(pv);
+
+ /* Set our own DTR */
+
+ pr_devel("HVSI@%x: ... setting mctrl\n", pv->termno);
+
+ hvsilib_write_mctrl(pv, 1);
+
+ /* Set the opened flag so reads are allowed */
+ wmb();
+ pv->opened = 1;
+}
+
+int hvsilib_open(struct hvsi_priv *pv, struct hvc_struct *hp)
+{
+ pr_devel("HVSI@%x: open !\n", pv->termno);
+
+ /* Keep track of the tty data structure */
+ pv->tty = tty_port_tty_get(&hp->port);
+
+ hvsilib_establish(pv);
+
+ return 0;
+}
+
+void hvsilib_close(struct hvsi_priv *pv, struct hvc_struct *hp)
+{
+ unsigned long flags;
+
+ pr_devel("HVSI@%x: close !\n", pv->termno);
+
+ if (!pv->is_console) {
+ pr_devel("HVSI@%x: Not a console, tearing down\n",
+ pv->termno);
+
+ /* Clear opened, synchronize with khvcd */
+ spin_lock_irqsave(&hp->lock, flags);
+ pv->opened = 0;
+ spin_unlock_irqrestore(&hp->lock, flags);
+
+ /* Clear our own DTR */
+ if (!pv->tty || (pv->tty->termios.c_cflag & HUPCL))
+ hvsilib_write_mctrl(pv, 0);
+
+ /* Tear down the connection */
+ hvsi_send_close(pv);
+ }
+
+ tty_kref_put(pv->tty);
+ pv->tty = NULL;
+}
+
+void hvsilib_init(struct hvsi_priv *pv,
+ int (*get_chars)(uint32_t termno, char *buf, int count),
+ int (*put_chars)(uint32_t termno, const char *buf,
+ int count),
+ int termno, int is_console)
+{
+ memset(pv, 0, sizeof(*pv));
+ pv->get_chars = get_chars;
+ pv->put_chars = put_chars;
+ pv->termno = termno;
+ pv->is_console = is_console;
+}