v4.19.13 snapshot.
diff --git a/arch/ia64/hp/sim/simserial.c b/arch/ia64/hp/sim/simserial.c
new file mode 100644
index 0000000..663388a
--- /dev/null
+++ b/arch/ia64/hp/sim/simserial.c
@@ -0,0 +1,521 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Simulated Serial Driver (fake serial)
+ *
+ * This driver is mostly used for bringup purposes and will go away.
+ * It has a strong dependency on the system console. All outputs
+ * are rerouted to the same facility as the one used by printk which, in our
+ * case means sys_sim.c console (goes via the simulator).
+ *
+ * Copyright (C) 1999-2000, 2002-2003 Hewlett-Packard Co
+ * Stephane Eranian <eranian@hpl.hp.com>
+ * David Mosberger-Tang <davidm@hpl.hp.com>
+ */
+
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/capability.h>
+#include <linux/circ_buf.h>
+#include <linux/console.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/sysrq.h>
+#include <linux/uaccess.h>
+
+#include <asm/hpsim.h>
+
+#include "hpsim_ssc.h"
+
+#undef SIMSERIAL_DEBUG /* define this to get some debug information */
+
+#define KEYBOARD_INTR 3 /* must match with simulator! */
+
+#define NR_PORTS 1 /* only one port for now */
+
+struct serial_state {
+ struct tty_port port;
+ struct circ_buf xmit;
+ int irq;
+ int x_char;
+};
+
+static struct serial_state rs_table[NR_PORTS];
+
+struct tty_driver *hp_simserial_driver;
+
+static struct console *console;
+
+static void receive_chars(struct tty_port *port)
+{
+ unsigned char ch;
+ static unsigned char seen_esc = 0;
+
+ while ( (ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR)) ) {
+ if (ch == 27 && seen_esc == 0) {
+ seen_esc = 1;
+ continue;
+ } else if (seen_esc == 1 && ch == 'O') {
+ seen_esc = 2;
+ continue;
+ } else if (seen_esc == 2) {
+ if (ch == 'P') /* F1 */
+ show_state();
+#ifdef CONFIG_MAGIC_SYSRQ
+ if (ch == 'S') { /* F4 */
+ do {
+ ch = ia64_ssc(0, 0, 0, 0, SSC_GETCHAR);
+ } while (!ch);
+ handle_sysrq(ch);
+ }
+#endif
+ seen_esc = 0;
+ continue;
+ }
+ seen_esc = 0;
+
+ if (tty_insert_flip_char(port, ch, TTY_NORMAL) == 0)
+ break;
+ }
+ tty_flip_buffer_push(port);
+}
+
+/*
+ * This is the serial driver's interrupt routine for a single port
+ */
+static irqreturn_t rs_interrupt_single(int irq, void *dev_id)
+{
+ struct serial_state *info = dev_id;
+
+ receive_chars(&info->port);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * -------------------------------------------------------------------
+ * Here ends the serial interrupt routines.
+ * -------------------------------------------------------------------
+ */
+
+static int rs_put_char(struct tty_struct *tty, unsigned char ch)
+{
+ struct serial_state *info = tty->driver_data;
+ unsigned long flags;
+
+ if (!info->xmit.buf)
+ return 0;
+
+ local_irq_save(flags);
+ if (CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) == 0) {
+ local_irq_restore(flags);
+ return 0;
+ }
+ info->xmit.buf[info->xmit.head] = ch;
+ info->xmit.head = (info->xmit.head + 1) & (SERIAL_XMIT_SIZE-1);
+ local_irq_restore(flags);
+ return 1;
+}
+
+static void transmit_chars(struct tty_struct *tty, struct serial_state *info,
+ int *intr_done)
+{
+ int count;
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ if (info->x_char) {
+ char c = info->x_char;
+
+ console->write(console, &c, 1);
+
+ info->x_char = 0;
+
+ goto out;
+ }
+
+ if (info->xmit.head == info->xmit.tail || tty->stopped) {
+#ifdef SIMSERIAL_DEBUG
+ printk("transmit_chars: head=%d, tail=%d, stopped=%d\n",
+ info->xmit.head, info->xmit.tail, tty->stopped);
+#endif
+ goto out;
+ }
+ /*
+ * We removed the loop and try to do it in to chunks. We need
+ * 2 operations maximum because it's a ring buffer.
+ *
+ * First from current to tail if possible.
+ * Then from the beginning of the buffer until necessary
+ */
+
+ count = min(CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE),
+ SERIAL_XMIT_SIZE - info->xmit.tail);
+ console->write(console, info->xmit.buf+info->xmit.tail, count);
+
+ info->xmit.tail = (info->xmit.tail+count) & (SERIAL_XMIT_SIZE-1);
+
+ /*
+ * We have more at the beginning of the buffer
+ */
+ count = CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+ if (count) {
+ console->write(console, info->xmit.buf, count);
+ info->xmit.tail += count;
+ }
+out:
+ local_irq_restore(flags);
+}
+
+static void rs_flush_chars(struct tty_struct *tty)
+{
+ struct serial_state *info = tty->driver_data;
+
+ if (info->xmit.head == info->xmit.tail || tty->stopped ||
+ !info->xmit.buf)
+ return;
+
+ transmit_chars(tty, info, NULL);
+}
+
+static int rs_write(struct tty_struct * tty,
+ const unsigned char *buf, int count)
+{
+ struct serial_state *info = tty->driver_data;
+ int c, ret = 0;
+ unsigned long flags;
+
+ if (!info->xmit.buf)
+ return 0;
+
+ local_irq_save(flags);
+ while (1) {
+ c = CIRC_SPACE_TO_END(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+ if (count < c)
+ c = count;
+ if (c <= 0) {
+ break;
+ }
+ memcpy(info->xmit.buf + info->xmit.head, buf, c);
+ info->xmit.head = ((info->xmit.head + c) &
+ (SERIAL_XMIT_SIZE-1));
+ buf += c;
+ count -= c;
+ ret += c;
+ }
+ local_irq_restore(flags);
+ /*
+ * Hey, we transmit directly from here in our case
+ */
+ if (CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE) &&
+ !tty->stopped)
+ transmit_chars(tty, info, NULL);
+
+ return ret;
+}
+
+static int rs_write_room(struct tty_struct *tty)
+{
+ struct serial_state *info = tty->driver_data;
+
+ return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+}
+
+static int rs_chars_in_buffer(struct tty_struct *tty)
+{
+ struct serial_state *info = tty->driver_data;
+
+ return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
+}
+
+static void rs_flush_buffer(struct tty_struct *tty)
+{
+ struct serial_state *info = tty->driver_data;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ info->xmit.head = info->xmit.tail = 0;
+ local_irq_restore(flags);
+
+ tty_wakeup(tty);
+}
+
+/*
+ * This function is used to send a high-priority XON/XOFF character to
+ * the device
+ */
+static void rs_send_xchar(struct tty_struct *tty, char ch)
+{
+ struct serial_state *info = tty->driver_data;
+
+ info->x_char = ch;
+ if (ch) {
+ /*
+ * I guess we could call console->write() directly but
+ * let's do that for now.
+ */
+ transmit_chars(tty, info, NULL);
+ }
+}
+
+/*
+ * ------------------------------------------------------------
+ * rs_throttle()
+ *
+ * This routine is called by the upper-layer tty layer to signal that
+ * incoming characters should be throttled.
+ * ------------------------------------------------------------
+ */
+static void rs_throttle(struct tty_struct * tty)
+{
+ if (I_IXOFF(tty))
+ rs_send_xchar(tty, STOP_CHAR(tty));
+
+ printk(KERN_INFO "simrs_throttle called\n");
+}
+
+static void rs_unthrottle(struct tty_struct * tty)
+{
+ struct serial_state *info = tty->driver_data;
+
+ if (I_IXOFF(tty)) {
+ if (info->x_char)
+ info->x_char = 0;
+ else
+ rs_send_xchar(tty, START_CHAR(tty));
+ }
+ printk(KERN_INFO "simrs_unthrottle called\n");
+}
+
+static int rs_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
+{
+ if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
+ (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
+ (cmd != TIOCMIWAIT)) {
+ if (tty_io_error(tty))
+ return -EIO;
+ }
+
+ switch (cmd) {
+ case TIOCGSERIAL:
+ case TIOCSSERIAL:
+ case TIOCSERGSTRUCT:
+ case TIOCMIWAIT:
+ return 0;
+ case TIOCSERCONFIG:
+ case TIOCSERGETLSR: /* Get line status register */
+ return -EINVAL;
+ case TIOCSERGWILD:
+ case TIOCSERSWILD:
+ /* "setserial -W" is called in Debian boot */
+ printk (KERN_INFO "TIOCSER?WILD ioctl obsolete, ignored.\n");
+ return 0;
+ }
+ return -ENOIOCTLCMD;
+}
+
+#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
+
+/*
+ * This routine will shutdown a serial port; interrupts are disabled, and
+ * DTR is dropped if the hangup on close termio flag is on.
+ */
+static void shutdown(struct tty_port *port)
+{
+ struct serial_state *info = container_of(port, struct serial_state,
+ port);
+ unsigned long flags;
+
+ local_irq_save(flags);
+ if (info->irq)
+ free_irq(info->irq, info);
+
+ if (info->xmit.buf) {
+ free_page((unsigned long) info->xmit.buf);
+ info->xmit.buf = NULL;
+ }
+ local_irq_restore(flags);
+}
+
+static void rs_close(struct tty_struct *tty, struct file * filp)
+{
+ struct serial_state *info = tty->driver_data;
+
+ tty_port_close(&info->port, tty, filp);
+}
+
+static void rs_hangup(struct tty_struct *tty)
+{
+ struct serial_state *info = tty->driver_data;
+
+ rs_flush_buffer(tty);
+ tty_port_hangup(&info->port);
+}
+
+static int activate(struct tty_port *port, struct tty_struct *tty)
+{
+ struct serial_state *state = container_of(port, struct serial_state,
+ port);
+ unsigned long flags, page;
+ int retval = 0;
+
+ page = get_zeroed_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ local_irq_save(flags);
+
+ if (state->xmit.buf)
+ free_page(page);
+ else
+ state->xmit.buf = (unsigned char *) page;
+
+ if (state->irq) {
+ retval = request_irq(state->irq, rs_interrupt_single, 0,
+ "simserial", state);
+ if (retval)
+ goto errout;
+ }
+
+ state->xmit.head = state->xmit.tail = 0;
+errout:
+ local_irq_restore(flags);
+ return retval;
+}
+
+
+/*
+ * This routine is called whenever a serial port is opened. It
+ * enables interrupts for a serial port, linking in its async structure into
+ * the IRQ chain. It also performs the serial-specific
+ * initialization for the tty structure.
+ */
+static int rs_open(struct tty_struct *tty, struct file * filp)
+{
+ struct serial_state *info = rs_table + tty->index;
+ struct tty_port *port = &info->port;
+
+ tty->driver_data = info;
+ port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+
+ /*
+ * figure out which console to use (should be one already)
+ */
+ console = console_drivers;
+ while (console) {
+ if ((console->flags & CON_ENABLED) && console->write) break;
+ console = console->next;
+ }
+
+ return tty_port_open(port, tty, filp);
+}
+
+/*
+ * /proc fs routines....
+ */
+
+static int rs_proc_show(struct seq_file *m, void *v)
+{
+ int i;
+
+ seq_printf(m, "simserinfo:1.0\n");
+ for (i = 0; i < NR_PORTS; i++)
+ seq_printf(m, "%d: uart:16550 port:3F8 irq:%d\n",
+ i, rs_table[i].irq);
+ return 0;
+}
+
+static const struct tty_operations hp_ops = {
+ .open = rs_open,
+ .close = rs_close,
+ .write = rs_write,
+ .put_char = rs_put_char,
+ .flush_chars = rs_flush_chars,
+ .write_room = rs_write_room,
+ .chars_in_buffer = rs_chars_in_buffer,
+ .flush_buffer = rs_flush_buffer,
+ .ioctl = rs_ioctl,
+ .throttle = rs_throttle,
+ .unthrottle = rs_unthrottle,
+ .send_xchar = rs_send_xchar,
+ .hangup = rs_hangup,
+ .proc_show = rs_proc_show,
+};
+
+static const struct tty_port_operations hp_port_ops = {
+ .activate = activate,
+ .shutdown = shutdown,
+};
+
+static int __init simrs_init(void)
+{
+ struct serial_state *state;
+ int retval;
+
+ if (!ia64_platform_is("hpsim"))
+ return -ENODEV;
+
+ hp_simserial_driver = alloc_tty_driver(NR_PORTS);
+ if (!hp_simserial_driver)
+ return -ENOMEM;
+
+ printk(KERN_INFO "SimSerial driver with no serial options enabled\n");
+
+ /* Initialize the tty_driver structure */
+
+ hp_simserial_driver->driver_name = "simserial";
+ hp_simserial_driver->name = "ttyS";
+ hp_simserial_driver->major = TTY_MAJOR;
+ hp_simserial_driver->minor_start = 64;
+ hp_simserial_driver->type = TTY_DRIVER_TYPE_SERIAL;
+ hp_simserial_driver->subtype = SERIAL_TYPE_NORMAL;
+ hp_simserial_driver->init_termios = tty_std_termios;
+ hp_simserial_driver->init_termios.c_cflag =
+ B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+ hp_simserial_driver->flags = TTY_DRIVER_REAL_RAW;
+ tty_set_operations(hp_simserial_driver, &hp_ops);
+
+ state = rs_table;
+ tty_port_init(&state->port);
+ state->port.ops = &hp_port_ops;
+ state->port.close_delay = 0; /* XXX really 0? */
+
+ retval = hpsim_get_irq(KEYBOARD_INTR);
+ if (retval < 0) {
+ printk(KERN_ERR "%s: out of interrupt vectors!\n",
+ __func__);
+ goto err_free_tty;
+ }
+
+ state->irq = retval;
+
+ /* the port is imaginary */
+ printk(KERN_INFO "ttyS0 at 0x03f8 (irq = %d) is a 16550\n", state->irq);
+
+ tty_port_link_device(&state->port, hp_simserial_driver, 0);
+ retval = tty_register_driver(hp_simserial_driver);
+ if (retval) {
+ printk(KERN_ERR "Couldn't register simserial driver\n");
+ goto err_free_tty;
+ }
+
+ return 0;
+err_free_tty:
+ put_tty_driver(hp_simserial_driver);
+ tty_port_destroy(&state->port);
+ return retval;
+}
+
+#ifndef MODULE
+__initcall(simrs_init);
+#endif