v4.19.13 snapshot.
diff --git a/drivers/usb/early/Makefile b/drivers/usb/early/Makefile
new file mode 100644
index 0000000..7b77b49
--- /dev/null
+++ b/drivers/usb/early/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for early USB devices
+#
+
+obj-$(CONFIG_EARLY_PRINTK_DBGP) += ehci-dbgp.o
+obj-$(CONFIG_EARLY_PRINTK_USB_XDBC) += xhci-dbc.o
diff --git a/drivers/usb/early/ehci-dbgp.c b/drivers/usb/early/ehci-dbgp.c
new file mode 100644
index 0000000..d633c2a
--- /dev/null
+++ b/drivers/usb/early/ehci-dbgp.c
@@ -0,0 +1,1096 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Standalone EHCI usb debug driver
+ *
+ * Originally written by:
+ * Eric W. Biederman" <ebiederm@xmission.com> and
+ * Yinghai Lu <yhlu.kernel@gmail.com>
+ *
+ * Changes for early/late printk and HW errata:
+ * Jason Wessel <jason.wessel@windriver.com>
+ * Copyright (C) 2009 Wind River Systems, Inc.
+ *
+ */
+
+#include <linux/console.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/pci_regs.h>
+#include <linux/pci_ids.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/ehci_def.h>
+#include <linux/delay.h>
+#include <linux/serial_core.h>
+#include <linux/kgdb.h>
+#include <linux/kthread.h>
+#include <asm/io.h>
+#include <asm/pci-direct.h>
+#include <asm/fixmap.h>
+
+/* The code here is intended to talk directly to the EHCI debug port
+ * and does not require that you have any kind of USB host controller
+ * drivers or USB device drivers compiled into the kernel.
+ *
+ * If you make a change to anything in here, the following test cases
+ * need to pass where a USB debug device works in the following
+ * configurations.
+ *
+ * 1. boot args: earlyprintk=dbgp
+ * o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
+ * o kernel compiled with CONFIG_USB_EHCI_HCD=y
+ * 2. boot args: earlyprintk=dbgp,keep
+ * o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
+ * o kernel compiled with CONFIG_USB_EHCI_HCD=y
+ * 3. boot args: earlyprintk=dbgp console=ttyUSB0
+ * o kernel has CONFIG_USB_EHCI_HCD=y and
+ * CONFIG_USB_SERIAL_DEBUG=y
+ * 4. boot args: earlyprintk=vga,dbgp
+ * o kernel compiled with # CONFIG_USB_EHCI_HCD is not set
+ * o kernel compiled with CONFIG_USB_EHCI_HCD=y
+ *
+ * For the 4th configuration you can turn on or off the DBGP_DEBUG
+ * such that you can debug the dbgp device's driver code.
+ */
+
+static int dbgp_phys_port = 1;
+
+static struct ehci_caps __iomem *ehci_caps;
+static struct ehci_regs __iomem *ehci_regs;
+static struct ehci_dbg_port __iomem *ehci_debug;
+static int dbgp_not_safe; /* Cannot use debug device during ehci reset */
+static unsigned int dbgp_endpoint_out;
+static unsigned int dbgp_endpoint_in;
+
+struct ehci_dev {
+ u32 bus;
+ u32 slot;
+ u32 func;
+};
+
+static struct ehci_dev ehci_dev;
+
+#define USB_DEBUG_DEVNUM 127
+
+#ifdef DBGP_DEBUG
+#define dbgp_printk printk
+static void dbgp_ehci_status(char *str)
+{
+ if (!ehci_debug)
+ return;
+ dbgp_printk("dbgp: %s\n", str);
+ dbgp_printk(" Debug control: %08x", readl(&ehci_debug->control));
+ dbgp_printk(" ehci cmd : %08x", readl(&ehci_regs->command));
+ dbgp_printk(" ehci conf flg: %08x\n",
+ readl(&ehci_regs->configured_flag));
+ dbgp_printk(" ehci status : %08x", readl(&ehci_regs->status));
+ dbgp_printk(" ehci portsc : %08x\n",
+ readl(&ehci_regs->port_status[dbgp_phys_port - 1]));
+}
+#else
+static inline void dbgp_ehci_status(char *str) { }
+static inline void dbgp_printk(const char *fmt, ...) { }
+#endif
+
+static inline u32 dbgp_len_update(u32 x, u32 len)
+{
+ return (x & ~0x0f) | (len & 0x0f);
+}
+
+#ifdef CONFIG_KGDB
+static struct kgdb_io kgdbdbgp_io_ops;
+#define dbgp_kgdb_mode (dbg_io_ops == &kgdbdbgp_io_ops)
+#else
+#define dbgp_kgdb_mode (0)
+#endif
+
+/* Local version of HC_LENGTH macro as ehci struct is not available here */
+#define EARLY_HC_LENGTH(p) (0x00ff & (p)) /* bits 7 : 0 */
+
+/*
+ * USB Packet IDs (PIDs)
+ */
+
+/* token */
+#define USB_PID_OUT 0xe1
+#define USB_PID_IN 0x69
+#define USB_PID_SOF 0xa5
+#define USB_PID_SETUP 0x2d
+/* handshake */
+#define USB_PID_ACK 0xd2
+#define USB_PID_NAK 0x5a
+#define USB_PID_STALL 0x1e
+#define USB_PID_NYET 0x96
+/* data */
+#define USB_PID_DATA0 0xc3
+#define USB_PID_DATA1 0x4b
+#define USB_PID_DATA2 0x87
+#define USB_PID_MDATA 0x0f
+/* Special */
+#define USB_PID_PREAMBLE 0x3c
+#define USB_PID_ERR 0x3c
+#define USB_PID_SPLIT 0x78
+#define USB_PID_PING 0xb4
+#define USB_PID_UNDEF_0 0xf0
+
+#define USB_PID_DATA_TOGGLE 0x88
+#define DBGP_CLAIM (DBGP_OWNER | DBGP_ENABLED | DBGP_INUSE)
+
+#define PCI_CAP_ID_EHCI_DEBUG 0xa
+
+#define HUB_ROOT_RESET_TIME 50 /* times are in msec */
+#define HUB_SHORT_RESET_TIME 10
+#define HUB_LONG_RESET_TIME 200
+#define HUB_RESET_TIMEOUT 500
+
+#define DBGP_MAX_PACKET 8
+#define DBGP_TIMEOUT (250 * 1000)
+#define DBGP_LOOPS 1000
+
+static inline u32 dbgp_pid_write_update(u32 x, u32 tok)
+{
+ static int data0 = USB_PID_DATA1;
+ data0 ^= USB_PID_DATA_TOGGLE;
+ return (x & 0xffff0000) | (data0 << 8) | (tok & 0xff);
+}
+
+static inline u32 dbgp_pid_read_update(u32 x, u32 tok)
+{
+ return (x & 0xffff0000) | (USB_PID_DATA0 << 8) | (tok & 0xff);
+}
+
+static int dbgp_wait_until_complete(void)
+{
+ u32 ctrl;
+ int loop = DBGP_TIMEOUT;
+
+ do {
+ ctrl = readl(&ehci_debug->control);
+ /* Stop when the transaction is finished */
+ if (ctrl & DBGP_DONE)
+ break;
+ udelay(1);
+ } while (--loop > 0);
+
+ if (!loop)
+ return -DBGP_TIMEOUT;
+
+ /*
+ * Now that we have observed the completed transaction,
+ * clear the done bit.
+ */
+ writel(ctrl | DBGP_DONE, &ehci_debug->control);
+ return (ctrl & DBGP_ERROR) ? -DBGP_ERRCODE(ctrl) : DBGP_LEN(ctrl);
+}
+
+static inline void dbgp_mdelay(int ms)
+{
+ int i;
+
+ while (ms--) {
+ for (i = 0; i < 1000; i++)
+ outb(0x1, 0x80);
+ }
+}
+
+static void dbgp_breath(void)
+{
+ /* Sleep to give the debug port a chance to breathe */
+}
+
+static int dbgp_wait_until_done(unsigned ctrl, int loop)
+{
+ u32 pids, lpid;
+ int ret;
+
+retry:
+ writel(ctrl | DBGP_GO, &ehci_debug->control);
+ ret = dbgp_wait_until_complete();
+ pids = readl(&ehci_debug->pids);
+ lpid = DBGP_PID_GET(pids);
+
+ if (ret < 0) {
+ /* A -DBGP_TIMEOUT failure here means the device has
+ * failed, perhaps because it was unplugged, in which
+ * case we do not want to hang the system so the dbgp
+ * will be marked as unsafe to use. EHCI reset is the
+ * only way to recover if you unplug the dbgp device.
+ */
+ if (ret == -DBGP_TIMEOUT && !dbgp_not_safe)
+ dbgp_not_safe = 1;
+ if (ret == -DBGP_ERR_BAD && --loop > 0)
+ goto retry;
+ return ret;
+ }
+
+ /*
+ * If the port is getting full or it has dropped data
+ * start pacing ourselves, not necessary but it's friendly.
+ */
+ if ((lpid == USB_PID_NAK) || (lpid == USB_PID_NYET))
+ dbgp_breath();
+
+ /* If I get a NACK reissue the transmission */
+ if (lpid == USB_PID_NAK) {
+ if (--loop > 0)
+ goto retry;
+ }
+
+ return ret;
+}
+
+static inline void dbgp_set_data(const void *buf, int size)
+{
+ const unsigned char *bytes = buf;
+ u32 lo, hi;
+ int i;
+
+ lo = hi = 0;
+ for (i = 0; i < 4 && i < size; i++)
+ lo |= bytes[i] << (8*i);
+ for (; i < 8 && i < size; i++)
+ hi |= bytes[i] << (8*(i - 4));
+ writel(lo, &ehci_debug->data03);
+ writel(hi, &ehci_debug->data47);
+}
+
+static inline void dbgp_get_data(void *buf, int size)
+{
+ unsigned char *bytes = buf;
+ u32 lo, hi;
+ int i;
+
+ lo = readl(&ehci_debug->data03);
+ hi = readl(&ehci_debug->data47);
+ for (i = 0; i < 4 && i < size; i++)
+ bytes[i] = (lo >> (8*i)) & 0xff;
+ for (; i < 8 && i < size; i++)
+ bytes[i] = (hi >> (8*(i - 4))) & 0xff;
+}
+
+static int dbgp_bulk_write(unsigned devnum, unsigned endpoint,
+ const char *bytes, int size)
+{
+ int ret;
+ u32 addr;
+ u32 pids, ctrl;
+
+ if (size > DBGP_MAX_PACKET)
+ return -1;
+
+ addr = DBGP_EPADDR(devnum, endpoint);
+
+ pids = readl(&ehci_debug->pids);
+ pids = dbgp_pid_write_update(pids, USB_PID_OUT);
+
+ ctrl = readl(&ehci_debug->control);
+ ctrl = dbgp_len_update(ctrl, size);
+ ctrl |= DBGP_OUT;
+ ctrl |= DBGP_GO;
+
+ dbgp_set_data(bytes, size);
+ writel(addr, &ehci_debug->address);
+ writel(pids, &ehci_debug->pids);
+ ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS);
+
+ return ret;
+}
+
+static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data,
+ int size, int loops)
+{
+ u32 pids, addr, ctrl;
+ int ret;
+
+ if (size > DBGP_MAX_PACKET)
+ return -1;
+
+ addr = DBGP_EPADDR(devnum, endpoint);
+
+ pids = readl(&ehci_debug->pids);
+ pids = dbgp_pid_read_update(pids, USB_PID_IN);
+
+ ctrl = readl(&ehci_debug->control);
+ ctrl = dbgp_len_update(ctrl, size);
+ ctrl &= ~DBGP_OUT;
+ ctrl |= DBGP_GO;
+
+ writel(addr, &ehci_debug->address);
+ writel(pids, &ehci_debug->pids);
+ ret = dbgp_wait_until_done(ctrl, loops);
+ if (ret < 0)
+ return ret;
+
+ if (size > ret)
+ size = ret;
+ dbgp_get_data(data, size);
+ return ret;
+}
+
+static int dbgp_control_msg(unsigned devnum, int requesttype,
+ int request, int value, int index, void *data, int size)
+{
+ u32 pids, addr, ctrl;
+ struct usb_ctrlrequest req;
+ int read;
+ int ret;
+
+ read = (requesttype & USB_DIR_IN) != 0;
+ if (size > (read ? DBGP_MAX_PACKET : 0))
+ return -1;
+
+ /* Compute the control message */
+ req.bRequestType = requesttype;
+ req.bRequest = request;
+ req.wValue = cpu_to_le16(value);
+ req.wIndex = cpu_to_le16(index);
+ req.wLength = cpu_to_le16(size);
+
+ pids = DBGP_PID_SET(USB_PID_DATA0, USB_PID_SETUP);
+ addr = DBGP_EPADDR(devnum, 0);
+
+ ctrl = readl(&ehci_debug->control);
+ ctrl = dbgp_len_update(ctrl, sizeof(req));
+ ctrl |= DBGP_OUT;
+ ctrl |= DBGP_GO;
+
+ /* Send the setup message */
+ dbgp_set_data(&req, sizeof(req));
+ writel(addr, &ehci_debug->address);
+ writel(pids, &ehci_debug->pids);
+ ret = dbgp_wait_until_done(ctrl, DBGP_LOOPS);
+ if (ret < 0)
+ return ret;
+
+ /* Read the result */
+ return dbgp_bulk_read(devnum, 0, data, size, DBGP_LOOPS);
+}
+
+/* Find a PCI capability */
+static u32 __init find_cap(u32 num, u32 slot, u32 func, int cap)
+{
+ u8 pos;
+ int bytes;
+
+ if (!(read_pci_config_16(num, slot, func, PCI_STATUS) &
+ PCI_STATUS_CAP_LIST))
+ return 0;
+
+ pos = read_pci_config_byte(num, slot, func, PCI_CAPABILITY_LIST);
+ for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
+ u8 id;
+
+ pos &= ~3;
+ id = read_pci_config_byte(num, slot, func, pos+PCI_CAP_LIST_ID);
+ if (id == 0xff)
+ break;
+ if (id == cap)
+ return pos;
+
+ pos = read_pci_config_byte(num, slot, func,
+ pos+PCI_CAP_LIST_NEXT);
+ }
+ return 0;
+}
+
+static u32 __init __find_dbgp(u32 bus, u32 slot, u32 func)
+{
+ u32 class;
+
+ class = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
+ if ((class >> 8) != PCI_CLASS_SERIAL_USB_EHCI)
+ return 0;
+
+ return find_cap(bus, slot, func, PCI_CAP_ID_EHCI_DEBUG);
+}
+
+static u32 __init find_dbgp(int ehci_num, u32 *rbus, u32 *rslot, u32 *rfunc)
+{
+ u32 bus, slot, func;
+
+ for (bus = 0; bus < 256; bus++) {
+ for (slot = 0; slot < 32; slot++) {
+ for (func = 0; func < 8; func++) {
+ unsigned cap;
+
+ cap = __find_dbgp(bus, slot, func);
+
+ if (!cap)
+ continue;
+ if (ehci_num-- != 0)
+ continue;
+ *rbus = bus;
+ *rslot = slot;
+ *rfunc = func;
+ return cap;
+ }
+ }
+ }
+ return 0;
+}
+
+static int dbgp_ehci_startup(void)
+{
+ u32 ctrl, cmd, status;
+ int loop;
+
+ /* Claim ownership, but do not enable yet */
+ ctrl = readl(&ehci_debug->control);
+ ctrl |= DBGP_OWNER;
+ ctrl &= ~(DBGP_ENABLED | DBGP_INUSE);
+ writel(ctrl, &ehci_debug->control);
+ udelay(1);
+
+ dbgp_ehci_status("EHCI startup");
+ /* Start the ehci running */
+ cmd = readl(&ehci_regs->command);
+ cmd &= ~(CMD_LRESET | CMD_IAAD | CMD_PSE | CMD_ASE | CMD_RESET);
+ cmd |= CMD_RUN;
+ writel(cmd, &ehci_regs->command);
+
+ /* Ensure everything is routed to the EHCI */
+ writel(FLAG_CF, &ehci_regs->configured_flag);
+
+ /* Wait until the controller is no longer halted */
+ loop = 1000;
+ do {
+ status = readl(&ehci_regs->status);
+ if (!(status & STS_HALT))
+ break;
+ udelay(1);
+ } while (--loop > 0);
+
+ if (!loop) {
+ dbgp_printk("ehci can not be started\n");
+ return -ENODEV;
+ }
+ dbgp_printk("ehci started\n");
+ return 0;
+}
+
+static int dbgp_ehci_controller_reset(void)
+{
+ int loop = 250 * 1000;
+ u32 cmd;
+
+ /* Reset the EHCI controller */
+ cmd = readl(&ehci_regs->command);
+ cmd |= CMD_RESET;
+ writel(cmd, &ehci_regs->command);
+ do {
+ cmd = readl(&ehci_regs->command);
+ } while ((cmd & CMD_RESET) && (--loop > 0));
+
+ if (!loop) {
+ dbgp_printk("can not reset ehci\n");
+ return -1;
+ }
+ dbgp_ehci_status("ehci reset done");
+ return 0;
+}
+static int ehci_wait_for_port(int port);
+/* Return 0 on success
+ * Return -ENODEV for any general failure
+ * Return -EIO if wait for port fails
+ */
+static int _dbgp_external_startup(void)
+{
+ int devnum;
+ struct usb_debug_descriptor dbgp_desc;
+ int ret;
+ u32 ctrl, portsc, cmd;
+ int dbg_port = dbgp_phys_port;
+ int tries = 3;
+ int reset_port_tries = 1;
+ int try_hard_once = 1;
+
+try_port_reset_again:
+ ret = dbgp_ehci_startup();
+ if (ret)
+ return ret;
+
+ /* Wait for a device to show up in the debug port */
+ ret = ehci_wait_for_port(dbg_port);
+ if (ret < 0) {
+ portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
+ if (!(portsc & PORT_CONNECT) && try_hard_once) {
+ /* Last ditch effort to try to force enable
+ * the debug device by using the packet test
+ * ehci command to try and wake it up. */
+ try_hard_once = 0;
+ cmd = readl(&ehci_regs->command);
+ cmd &= ~CMD_RUN;
+ writel(cmd, &ehci_regs->command);
+ portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
+ portsc |= PORT_TEST_PKT;
+ writel(portsc, &ehci_regs->port_status[dbg_port - 1]);
+ dbgp_ehci_status("Trying to force debug port online");
+ mdelay(50);
+ dbgp_ehci_controller_reset();
+ goto try_port_reset_again;
+ } else if (reset_port_tries--) {
+ goto try_port_reset_again;
+ }
+ dbgp_printk("No device found in debug port\n");
+ return -EIO;
+ }
+ dbgp_ehci_status("wait for port done");
+
+ /* Enable the debug port */
+ ctrl = readl(&ehci_debug->control);
+ ctrl |= DBGP_CLAIM;
+ writel(ctrl, &ehci_debug->control);
+ ctrl = readl(&ehci_debug->control);
+ if ((ctrl & DBGP_CLAIM) != DBGP_CLAIM) {
+ dbgp_printk("No device in debug port\n");
+ writel(ctrl & ~DBGP_CLAIM, &ehci_debug->control);
+ return -ENODEV;
+ }
+ dbgp_ehci_status("debug ported enabled");
+
+ /* Completely transfer the debug device to the debug controller */
+ portsc = readl(&ehci_regs->port_status[dbg_port - 1]);
+ portsc &= ~PORT_PE;
+ writel(portsc, &ehci_regs->port_status[dbg_port - 1]);
+
+ dbgp_mdelay(100);
+
+try_again:
+ /* Find the debug device and make it device number 127 */
+ for (devnum = 0; devnum <= 127; devnum++) {
+ ret = dbgp_control_msg(devnum,
+ USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
+ USB_REQ_GET_DESCRIPTOR, (USB_DT_DEBUG << 8), 0,
+ &dbgp_desc, sizeof(dbgp_desc));
+ if (ret > 0)
+ break;
+ }
+ if (devnum > 127) {
+ dbgp_printk("Could not find attached debug device\n");
+ goto err;
+ }
+ dbgp_endpoint_out = dbgp_desc.bDebugOutEndpoint;
+ dbgp_endpoint_in = dbgp_desc.bDebugInEndpoint;
+
+ /* Move the device to 127 if it isn't already there */
+ if (devnum != USB_DEBUG_DEVNUM) {
+ ret = dbgp_control_msg(devnum,
+ USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
+ USB_REQ_SET_ADDRESS, USB_DEBUG_DEVNUM, 0, NULL, 0);
+ if (ret < 0) {
+ dbgp_printk("Could not move attached device to %d\n",
+ USB_DEBUG_DEVNUM);
+ goto err;
+ }
+ dbgp_printk("debug device renamed to 127\n");
+ }
+
+ /* Enable the debug interface */
+ ret = dbgp_control_msg(USB_DEBUG_DEVNUM,
+ USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
+ USB_REQ_SET_FEATURE, USB_DEVICE_DEBUG_MODE, 0, NULL, 0);
+ if (ret < 0) {
+ dbgp_printk(" Could not enable the debug device\n");
+ goto err;
+ }
+ dbgp_printk("debug interface enabled\n");
+ /* Perform a small write to get the even/odd data state in sync
+ */
+ ret = dbgp_bulk_write(USB_DEBUG_DEVNUM, dbgp_endpoint_out, " ", 1);
+ if (ret < 0) {
+ dbgp_printk("dbgp_bulk_write failed: %d\n", ret);
+ goto err;
+ }
+ dbgp_printk("small write done\n");
+ dbgp_not_safe = 0;
+
+ return 0;
+err:
+ if (tries--)
+ goto try_again;
+ return -ENODEV;
+}
+
+static int ehci_reset_port(int port)
+{
+ u32 portsc;
+ u32 delay_time, delay;
+ int loop;
+
+ dbgp_ehci_status("reset port");
+ /* Reset the usb debug port */
+ portsc = readl(&ehci_regs->port_status[port - 1]);
+ portsc &= ~PORT_PE;
+ portsc |= PORT_RESET;
+ writel(portsc, &ehci_regs->port_status[port - 1]);
+
+ delay = HUB_ROOT_RESET_TIME;
+ for (delay_time = 0; delay_time < HUB_RESET_TIMEOUT;
+ delay_time += delay) {
+ dbgp_mdelay(delay);
+ portsc = readl(&ehci_regs->port_status[port - 1]);
+ if (!(portsc & PORT_RESET))
+ break;
+ }
+ if (portsc & PORT_RESET) {
+ /* force reset to complete */
+ loop = 100 * 1000;
+ writel(portsc & ~(PORT_RWC_BITS | PORT_RESET),
+ &ehci_regs->port_status[port - 1]);
+ do {
+ udelay(1);
+ portsc = readl(&ehci_regs->port_status[port-1]);
+ } while ((portsc & PORT_RESET) && (--loop > 0));
+ }
+
+ /* Device went away? */
+ if (!(portsc & PORT_CONNECT))
+ return -ENOTCONN;
+
+ /* bomb out completely if something weird happened */
+ if ((portsc & PORT_CSC))
+ return -EINVAL;
+
+ /* If we've finished resetting, then break out of the loop */
+ if (!(portsc & PORT_RESET) && (portsc & PORT_PE))
+ return 0;
+ return -EBUSY;
+}
+
+static int ehci_wait_for_port(int port)
+{
+ u32 status;
+ int ret, reps;
+
+ for (reps = 0; reps < 300; reps++) {
+ status = readl(&ehci_regs->status);
+ if (status & STS_PCD)
+ break;
+ dbgp_mdelay(1);
+ }
+ ret = ehci_reset_port(port);
+ if (ret == 0)
+ return 0;
+ return -ENOTCONN;
+}
+
+typedef void (*set_debug_port_t)(int port);
+
+static void __init default_set_debug_port(int port)
+{
+}
+
+static set_debug_port_t __initdata set_debug_port = default_set_debug_port;
+
+static void __init nvidia_set_debug_port(int port)
+{
+ u32 dword;
+ dword = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
+ 0x74);
+ dword &= ~(0x0f<<12);
+ dword |= ((port & 0x0f)<<12);
+ write_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func, 0x74,
+ dword);
+ dbgp_printk("set debug port to %d\n", port);
+}
+
+static void __init detect_set_debug_port(void)
+{
+ u32 vendorid;
+
+ vendorid = read_pci_config(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
+ 0x00);
+
+ if ((vendorid & 0xffff) == 0x10de) {
+ dbgp_printk("using nvidia set_debug_port\n");
+ set_debug_port = nvidia_set_debug_port;
+ }
+}
+
+/* The code in early_ehci_bios_handoff() is derived from the usb pci
+ * quirk initialization, but altered so as to use the early PCI
+ * routines. */
+#define EHCI_USBLEGSUP_BIOS (1 << 16) /* BIOS semaphore */
+#define EHCI_USBLEGCTLSTS 4 /* legacy control/status */
+static void __init early_ehci_bios_handoff(void)
+{
+ u32 hcc_params = readl(&ehci_caps->hcc_params);
+ int offset = (hcc_params >> 8) & 0xff;
+ u32 cap;
+ int msec;
+
+ if (!offset)
+ return;
+
+ cap = read_pci_config(ehci_dev.bus, ehci_dev.slot,
+ ehci_dev.func, offset);
+ dbgp_printk("dbgp: ehci BIOS state %08x\n", cap);
+
+ if ((cap & 0xff) == 1 && (cap & EHCI_USBLEGSUP_BIOS)) {
+ dbgp_printk("dbgp: BIOS handoff\n");
+ write_pci_config_byte(ehci_dev.bus, ehci_dev.slot,
+ ehci_dev.func, offset + 3, 1);
+ }
+
+ /* if boot firmware now owns EHCI, spin till it hands it over. */
+ msec = 1000;
+ while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
+ mdelay(10);
+ msec -= 10;
+ cap = read_pci_config(ehci_dev.bus, ehci_dev.slot,
+ ehci_dev.func, offset);
+ }
+
+ if (cap & EHCI_USBLEGSUP_BIOS) {
+ /* well, possibly buggy BIOS... try to shut it down,
+ * and hope nothing goes too wrong */
+ dbgp_printk("dbgp: BIOS handoff failed: %08x\n", cap);
+ write_pci_config_byte(ehci_dev.bus, ehci_dev.slot,
+ ehci_dev.func, offset + 2, 0);
+ }
+
+ /* just in case, always disable EHCI SMIs */
+ write_pci_config_byte(ehci_dev.bus, ehci_dev.slot, ehci_dev.func,
+ offset + EHCI_USBLEGCTLSTS, 0);
+}
+
+static int __init ehci_setup(void)
+{
+ u32 ctrl, portsc, hcs_params;
+ u32 debug_port, new_debug_port = 0, n_ports;
+ int ret, i;
+ int port_map_tried;
+ int playtimes = 3;
+
+ early_ehci_bios_handoff();
+
+try_next_time:
+ port_map_tried = 0;
+
+try_next_port:
+
+ hcs_params = readl(&ehci_caps->hcs_params);
+ debug_port = HCS_DEBUG_PORT(hcs_params);
+ dbgp_phys_port = debug_port;
+ n_ports = HCS_N_PORTS(hcs_params);
+
+ dbgp_printk("debug_port: %d\n", debug_port);
+ dbgp_printk("n_ports: %d\n", n_ports);
+ dbgp_ehci_status("");
+
+ for (i = 1; i <= n_ports; i++) {
+ portsc = readl(&ehci_regs->port_status[i-1]);
+ dbgp_printk("portstatus%d: %08x\n", i, portsc);
+ }
+
+ if (port_map_tried && (new_debug_port != debug_port)) {
+ if (--playtimes) {
+ set_debug_port(new_debug_port);
+ goto try_next_time;
+ }
+ return -1;
+ }
+
+ /* Only reset the controller if it is not already in the
+ * configured state */
+ if (!(readl(&ehci_regs->configured_flag) & FLAG_CF)) {
+ if (dbgp_ehci_controller_reset() != 0)
+ return -1;
+ } else {
+ dbgp_ehci_status("ehci skip - already configured");
+ }
+
+ ret = _dbgp_external_startup();
+ if (ret == -EIO)
+ goto next_debug_port;
+
+ if (ret < 0) {
+ /* Things didn't work so remove my claim */
+ ctrl = readl(&ehci_debug->control);
+ ctrl &= ~(DBGP_CLAIM | DBGP_OUT);
+ writel(ctrl, &ehci_debug->control);
+ return -1;
+ }
+ return 0;
+
+next_debug_port:
+ port_map_tried |= (1<<(debug_port - 1));
+ new_debug_port = ((debug_port-1+1)%n_ports) + 1;
+ if (port_map_tried != ((1<<n_ports) - 1)) {
+ set_debug_port(new_debug_port);
+ goto try_next_port;
+ }
+ if (--playtimes) {
+ set_debug_port(new_debug_port);
+ goto try_next_time;
+ }
+
+ return -1;
+}
+
+int __init early_dbgp_init(char *s)
+{
+ u32 debug_port, bar, offset;
+ u32 bus, slot, func, cap;
+ void __iomem *ehci_bar;
+ u32 dbgp_num;
+ u32 bar_val;
+ char *e;
+ int ret;
+ u8 byte;
+
+ if (!early_pci_allowed())
+ return -1;
+
+ dbgp_num = 0;
+ if (*s)
+ dbgp_num = simple_strtoul(s, &e, 10);
+ dbgp_printk("dbgp_num: %d\n", dbgp_num);
+
+ cap = find_dbgp(dbgp_num, &bus, &slot, &func);
+ if (!cap)
+ return -1;
+
+ dbgp_printk("Found EHCI debug port on %02x:%02x.%1x\n", bus, slot,
+ func);
+
+ debug_port = read_pci_config(bus, slot, func, cap);
+ bar = (debug_port >> 29) & 0x7;
+ bar = (bar * 4) + 0xc;
+ offset = (debug_port >> 16) & 0xfff;
+ dbgp_printk("bar: %02x offset: %03x\n", bar, offset);
+ if (bar != PCI_BASE_ADDRESS_0) {
+ dbgp_printk("only debug ports on bar 1 handled.\n");
+
+ return -1;
+ }
+
+ bar_val = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
+ dbgp_printk("bar_val: %02x offset: %03x\n", bar_val, offset);
+ if (bar_val & ~PCI_BASE_ADDRESS_MEM_MASK) {
+ dbgp_printk("only simple 32bit mmio bars supported\n");
+
+ return -1;
+ }
+
+ /* double check if the mem space is enabled */
+ byte = read_pci_config_byte(bus, slot, func, 0x04);
+ if (!(byte & 0x2)) {
+ byte |= 0x02;
+ write_pci_config_byte(bus, slot, func, 0x04, byte);
+ dbgp_printk("mmio for ehci enabled\n");
+ }
+
+ /*
+ * FIXME I don't have the bar size so just guess PAGE_SIZE is more
+ * than enough. 1K is the biggest I have seen.
+ */
+ set_fixmap_nocache(FIX_DBGP_BASE, bar_val & PAGE_MASK);
+ ehci_bar = (void __iomem *)__fix_to_virt(FIX_DBGP_BASE);
+ ehci_bar += bar_val & ~PAGE_MASK;
+ dbgp_printk("ehci_bar: %p\n", ehci_bar);
+
+ ehci_caps = ehci_bar;
+ ehci_regs = ehci_bar + EARLY_HC_LENGTH(readl(&ehci_caps->hc_capbase));
+ ehci_debug = ehci_bar + offset;
+ ehci_dev.bus = bus;
+ ehci_dev.slot = slot;
+ ehci_dev.func = func;
+
+ detect_set_debug_port();
+
+ ret = ehci_setup();
+ if (ret < 0) {
+ dbgp_printk("ehci_setup failed\n");
+ ehci_debug = NULL;
+
+ return -1;
+ }
+ dbgp_ehci_status("early_init_complete");
+
+ return 0;
+}
+
+static void early_dbgp_write(struct console *con, const char *str, u32 n)
+{
+ int chunk, ret;
+ char buf[DBGP_MAX_PACKET];
+ int use_cr = 0;
+ u32 cmd, ctrl;
+ int reset_run = 0;
+
+ if (!ehci_debug || dbgp_not_safe)
+ return;
+
+ cmd = readl(&ehci_regs->command);
+ if (unlikely(!(cmd & CMD_RUN))) {
+ /* If the ehci controller is not in the run state do extended
+ * checks to see if the acpi or some other initialization also
+ * reset the ehci debug port */
+ ctrl = readl(&ehci_debug->control);
+ if (!(ctrl & DBGP_ENABLED)) {
+ dbgp_not_safe = 1;
+ _dbgp_external_startup();
+ } else {
+ cmd |= CMD_RUN;
+ writel(cmd, &ehci_regs->command);
+ reset_run = 1;
+ }
+ }
+ while (n > 0) {
+ for (chunk = 0; chunk < DBGP_MAX_PACKET && n > 0;
+ str++, chunk++, n--) {
+ if (!use_cr && *str == '\n') {
+ use_cr = 1;
+ buf[chunk] = '\r';
+ str--;
+ n++;
+ continue;
+ }
+ if (use_cr)
+ use_cr = 0;
+ buf[chunk] = *str;
+ }
+ if (chunk > 0) {
+ ret = dbgp_bulk_write(USB_DEBUG_DEVNUM,
+ dbgp_endpoint_out, buf, chunk);
+ }
+ }
+ if (unlikely(reset_run)) {
+ cmd = readl(&ehci_regs->command);
+ cmd &= ~CMD_RUN;
+ writel(cmd, &ehci_regs->command);
+ }
+}
+
+struct console early_dbgp_console = {
+ .name = "earlydbg",
+ .write = early_dbgp_write,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+};
+
+#if IS_ENABLED(CONFIG_USB)
+int dbgp_reset_prep(struct usb_hcd *hcd)
+{
+ int ret = xen_dbgp_reset_prep(hcd);
+ u32 ctrl;
+
+ if (ret)
+ return ret;
+
+ dbgp_not_safe = 1;
+ if (!ehci_debug)
+ return 0;
+
+ if ((early_dbgp_console.index != -1 &&
+ !(early_dbgp_console.flags & CON_BOOT)) ||
+ dbgp_kgdb_mode)
+ return 1;
+ /* This means the console is not initialized, or should get
+ * shutdown so as to allow for reuse of the usb device, which
+ * means it is time to shutdown the usb debug port. */
+ ctrl = readl(&ehci_debug->control);
+ if (ctrl & DBGP_ENABLED) {
+ ctrl &= ~(DBGP_CLAIM);
+ writel(ctrl, &ehci_debug->control);
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dbgp_reset_prep);
+
+int dbgp_external_startup(struct usb_hcd *hcd)
+{
+ return xen_dbgp_external_startup(hcd) ?: _dbgp_external_startup();
+}
+EXPORT_SYMBOL_GPL(dbgp_external_startup);
+#endif /* USB */
+
+#ifdef CONFIG_KGDB
+
+static char kgdbdbgp_buf[DBGP_MAX_PACKET];
+static int kgdbdbgp_buf_sz;
+static int kgdbdbgp_buf_idx;
+static int kgdbdbgp_loop_cnt = DBGP_LOOPS;
+
+static int kgdbdbgp_read_char(void)
+{
+ int ret;
+
+ if (kgdbdbgp_buf_idx < kgdbdbgp_buf_sz) {
+ char ch = kgdbdbgp_buf[kgdbdbgp_buf_idx++];
+ return ch;
+ }
+
+ ret = dbgp_bulk_read(USB_DEBUG_DEVNUM, dbgp_endpoint_in,
+ &kgdbdbgp_buf, DBGP_MAX_PACKET,
+ kgdbdbgp_loop_cnt);
+ if (ret <= 0)
+ return NO_POLL_CHAR;
+ kgdbdbgp_buf_sz = ret;
+ kgdbdbgp_buf_idx = 1;
+ return kgdbdbgp_buf[0];
+}
+
+static void kgdbdbgp_write_char(u8 chr)
+{
+ early_dbgp_write(NULL, &chr, 1);
+}
+
+static struct kgdb_io kgdbdbgp_io_ops = {
+ .name = "kgdbdbgp",
+ .read_char = kgdbdbgp_read_char,
+ .write_char = kgdbdbgp_write_char,
+};
+
+static int kgdbdbgp_wait_time;
+
+static int __init kgdbdbgp_parse_config(char *str)
+{
+ char *ptr;
+
+ if (!ehci_debug) {
+ if (early_dbgp_init(str))
+ return -1;
+ }
+ ptr = strchr(str, ',');
+ if (ptr) {
+ ptr++;
+ kgdbdbgp_wait_time = simple_strtoul(ptr, &ptr, 10);
+ }
+ kgdb_register_io_module(&kgdbdbgp_io_ops);
+ kgdbdbgp_io_ops.is_console = early_dbgp_console.index != -1;
+
+ return 0;
+}
+early_param("kgdbdbgp", kgdbdbgp_parse_config);
+
+static int kgdbdbgp_reader_thread(void *ptr)
+{
+ int ret;
+
+ while (readl(&ehci_debug->control) & DBGP_ENABLED) {
+ kgdbdbgp_loop_cnt = 1;
+ ret = kgdbdbgp_read_char();
+ kgdbdbgp_loop_cnt = DBGP_LOOPS;
+ if (ret != NO_POLL_CHAR) {
+ if (ret == 0x3 || ret == '$') {
+ if (ret == '$')
+ kgdbdbgp_buf_idx--;
+ kgdb_breakpoint();
+ }
+ continue;
+ }
+ schedule_timeout_interruptible(kgdbdbgp_wait_time * HZ);
+ }
+ return 0;
+}
+
+static int __init kgdbdbgp_start_thread(void)
+{
+ if (dbgp_kgdb_mode && kgdbdbgp_wait_time)
+ kthread_run(kgdbdbgp_reader_thread, NULL, "%s", "dbgp");
+
+ return 0;
+}
+device_initcall(kgdbdbgp_start_thread);
+#endif /* CONFIG_KGDB */
diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c
new file mode 100644
index 0000000..e15e896
--- /dev/null
+++ b/drivers/usb/early/xhci-dbc.c
@@ -0,0 +1,1010 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * xhci-dbc.c - xHCI debug capability early driver
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/console.h>
+#include <linux/pci_regs.h>
+#include <linux/pci_ids.h>
+#include <linux/bootmem.h>
+#include <linux/io.h>
+#include <asm/pci-direct.h>
+#include <asm/fixmap.h>
+#include <linux/bcd.h>
+#include <linux/export.h>
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+
+#include "../host/xhci.h"
+#include "xhci-dbc.h"
+
+static struct xdbc_state xdbc;
+static bool early_console_keep;
+
+#ifdef XDBC_TRACE
+#define xdbc_trace trace_printk
+#else
+static inline void xdbc_trace(const char *fmt, ...) { }
+#endif /* XDBC_TRACE */
+
+static void __iomem * __init xdbc_map_pci_mmio(u32 bus, u32 dev, u32 func)
+{
+ u64 val64, sz64, mask64;
+ void __iomem *base;
+ u32 val, sz;
+ u8 byte;
+
+ val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, ~0);
+ sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0, val);
+
+ if (val == 0xffffffff || sz == 0xffffffff) {
+ pr_notice("invalid mmio bar\n");
+ return NULL;
+ }
+
+ val64 = val & PCI_BASE_ADDRESS_MEM_MASK;
+ sz64 = sz & PCI_BASE_ADDRESS_MEM_MASK;
+ mask64 = PCI_BASE_ADDRESS_MEM_MASK;
+
+ if ((val & PCI_BASE_ADDRESS_MEM_TYPE_MASK) == PCI_BASE_ADDRESS_MEM_TYPE_64) {
+ val = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, ~0);
+ sz = read_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4);
+ write_pci_config(bus, dev, func, PCI_BASE_ADDRESS_0 + 4, val);
+
+ val64 |= (u64)val << 32;
+ sz64 |= (u64)sz << 32;
+ mask64 |= ~0ULL << 32;
+ }
+
+ sz64 &= mask64;
+
+ if (!sz64) {
+ pr_notice("invalid mmio address\n");
+ return NULL;
+ }
+
+ sz64 = 1ULL << __ffs64(sz64);
+
+ /* Check if the mem space is enabled: */
+ byte = read_pci_config_byte(bus, dev, func, PCI_COMMAND);
+ if (!(byte & PCI_COMMAND_MEMORY)) {
+ byte |= PCI_COMMAND_MEMORY;
+ write_pci_config_byte(bus, dev, func, PCI_COMMAND, byte);
+ }
+
+ xdbc.xhci_start = val64;
+ xdbc.xhci_length = sz64;
+ base = early_ioremap(val64, sz64);
+
+ return base;
+}
+
+static void * __init xdbc_get_page(dma_addr_t *dma_addr)
+{
+ void *virt;
+
+ virt = alloc_bootmem_pages_nopanic(PAGE_SIZE);
+ if (!virt)
+ return NULL;
+
+ if (dma_addr)
+ *dma_addr = (dma_addr_t)__pa(virt);
+
+ return virt;
+}
+
+static u32 __init xdbc_find_dbgp(int xdbc_num, u32 *b, u32 *d, u32 *f)
+{
+ u32 bus, dev, func, class;
+
+ for (bus = 0; bus < XDBC_PCI_MAX_BUSES; bus++) {
+ for (dev = 0; dev < XDBC_PCI_MAX_DEVICES; dev++) {
+ for (func = 0; func < XDBC_PCI_MAX_FUNCTION; func++) {
+
+ class = read_pci_config(bus, dev, func, PCI_CLASS_REVISION);
+ if ((class >> 8) != PCI_CLASS_SERIAL_USB_XHCI)
+ continue;
+
+ if (xdbc_num-- != 0)
+ continue;
+
+ *b = bus;
+ *d = dev;
+ *f = func;
+
+ return 0;
+ }
+ }
+ }
+
+ return -1;
+}
+
+static int handshake(void __iomem *ptr, u32 mask, u32 done, int wait, int delay)
+{
+ u32 result;
+
+ do {
+ result = readl(ptr);
+ result &= mask;
+ if (result == done)
+ return 0;
+ udelay(delay);
+ wait -= delay;
+ } while (wait > 0);
+
+ return -ETIMEDOUT;
+}
+
+static void __init xdbc_bios_handoff(void)
+{
+ int offset, timeout;
+ u32 val;
+
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_LEGACY);
+ val = readl(xdbc.xhci_base + offset);
+
+ if (val & XHCI_HC_BIOS_OWNED) {
+ writel(val | XHCI_HC_OS_OWNED, xdbc.xhci_base + offset);
+ timeout = handshake(xdbc.xhci_base + offset, XHCI_HC_BIOS_OWNED, 0, 5000, 10);
+
+ if (timeout) {
+ pr_notice("failed to hand over xHCI control from BIOS\n");
+ writel(val & ~XHCI_HC_BIOS_OWNED, xdbc.xhci_base + offset);
+ }
+ }
+
+ /* Disable BIOS SMIs and clear all SMI events: */
+ val = readl(xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
+ val &= XHCI_LEGACY_DISABLE_SMI;
+ val |= XHCI_LEGACY_SMI_EVENTS;
+ writel(val, xdbc.xhci_base + offset + XHCI_LEGACY_CONTROL_OFFSET);
+}
+
+static int __init
+xdbc_alloc_ring(struct xdbc_segment *seg, struct xdbc_ring *ring)
+{
+ seg->trbs = xdbc_get_page(&seg->dma);
+ if (!seg->trbs)
+ return -ENOMEM;
+
+ ring->segment = seg;
+
+ return 0;
+}
+
+static void __init xdbc_free_ring(struct xdbc_ring *ring)
+{
+ struct xdbc_segment *seg = ring->segment;
+
+ if (!seg)
+ return;
+
+ free_bootmem(seg->dma, PAGE_SIZE);
+ ring->segment = NULL;
+}
+
+static void xdbc_reset_ring(struct xdbc_ring *ring)
+{
+ struct xdbc_segment *seg = ring->segment;
+ struct xdbc_trb *link_trb;
+
+ memset(seg->trbs, 0, PAGE_SIZE);
+
+ ring->enqueue = seg->trbs;
+ ring->dequeue = seg->trbs;
+ ring->cycle_state = 1;
+
+ if (ring != &xdbc.evt_ring) {
+ link_trb = &seg->trbs[XDBC_TRBS_PER_SEGMENT - 1];
+ link_trb->field[0] = cpu_to_le32(lower_32_bits(seg->dma));
+ link_trb->field[1] = cpu_to_le32(upper_32_bits(seg->dma));
+ link_trb->field[3] = cpu_to_le32(TRB_TYPE(TRB_LINK)) | cpu_to_le32(LINK_TOGGLE);
+ }
+}
+
+static inline void xdbc_put_utf16(u16 *s, const char *c, size_t size)
+{
+ int i;
+
+ for (i = 0; i < size; i++)
+ s[i] = cpu_to_le16(c[i]);
+}
+
+static void xdbc_mem_init(void)
+{
+ struct xdbc_ep_context *ep_in, *ep_out;
+ struct usb_string_descriptor *s_desc;
+ struct xdbc_erst_entry *entry;
+ struct xdbc_strings *strings;
+ struct xdbc_context *ctx;
+ unsigned int max_burst;
+ u32 string_length;
+ int index = 0;
+ u32 dev_info;
+
+ xdbc_reset_ring(&xdbc.evt_ring);
+ xdbc_reset_ring(&xdbc.in_ring);
+ xdbc_reset_ring(&xdbc.out_ring);
+ memset(xdbc.table_base, 0, PAGE_SIZE);
+ memset(xdbc.out_buf, 0, PAGE_SIZE);
+
+ /* Initialize event ring segment table: */
+ xdbc.erst_size = 16;
+ xdbc.erst_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.erst_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+
+ index += XDBC_ERST_ENTRY_NUM;
+ entry = (struct xdbc_erst_entry *)xdbc.erst_base;
+
+ entry->seg_addr = cpu_to_le64(xdbc.evt_seg.dma);
+ entry->seg_size = cpu_to_le32(XDBC_TRBS_PER_SEGMENT);
+ entry->__reserved_0 = 0;
+
+ /* Initialize ERST registers: */
+ writel(1, &xdbc.xdbc_reg->ersts);
+ xdbc_write64(xdbc.erst_dma, &xdbc.xdbc_reg->erstba);
+ xdbc_write64(xdbc.evt_seg.dma, &xdbc.xdbc_reg->erdp);
+
+ /* Debug capability contexts: */
+ xdbc.dbcc_size = 64 * 3;
+ xdbc.dbcc_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.dbcc_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+
+ index += XDBC_DBCC_ENTRY_NUM;
+
+ /* Popluate the strings: */
+ xdbc.string_size = sizeof(struct xdbc_strings);
+ xdbc.string_base = xdbc.table_base + index * XDBC_TABLE_ENTRY_SIZE;
+ xdbc.string_dma = xdbc.table_dma + index * XDBC_TABLE_ENTRY_SIZE;
+ strings = (struct xdbc_strings *)xdbc.string_base;
+
+ index += XDBC_STRING_ENTRY_NUM;
+
+ /* Serial string: */
+ s_desc = (struct usb_string_descriptor *)strings->serial;
+ s_desc->bLength = (strlen(XDBC_STRING_SERIAL) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_SERIAL, strlen(XDBC_STRING_SERIAL));
+ string_length = s_desc->bLength;
+ string_length <<= 8;
+
+ /* Product string: */
+ s_desc = (struct usb_string_descriptor *)strings->product;
+ s_desc->bLength = (strlen(XDBC_STRING_PRODUCT) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_PRODUCT, strlen(XDBC_STRING_PRODUCT));
+ string_length += s_desc->bLength;
+ string_length <<= 8;
+
+ /* Manufacture string: */
+ s_desc = (struct usb_string_descriptor *)strings->manufacturer;
+ s_desc->bLength = (strlen(XDBC_STRING_MANUFACTURER) + 1) * 2;
+ s_desc->bDescriptorType = USB_DT_STRING;
+
+ xdbc_put_utf16(s_desc->wData, XDBC_STRING_MANUFACTURER, strlen(XDBC_STRING_MANUFACTURER));
+ string_length += s_desc->bLength;
+ string_length <<= 8;
+
+ /* String0: */
+ strings->string0[0] = 4;
+ strings->string0[1] = USB_DT_STRING;
+ strings->string0[2] = 0x09;
+ strings->string0[3] = 0x04;
+
+ string_length += 4;
+
+ /* Populate info Context: */
+ ctx = (struct xdbc_context *)xdbc.dbcc_base;
+
+ ctx->info.string0 = cpu_to_le64(xdbc.string_dma);
+ ctx->info.manufacturer = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH);
+ ctx->info.product = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 2);
+ ctx->info.serial = cpu_to_le64(xdbc.string_dma + XDBC_MAX_STRING_LENGTH * 3);
+ ctx->info.length = cpu_to_le32(string_length);
+
+ /* Populate bulk out endpoint context: */
+ max_burst = DEBUG_MAX_BURST(readl(&xdbc.xdbc_reg->control));
+ ep_out = (struct xdbc_ep_context *)&ctx->out;
+
+ ep_out->ep_info1 = 0;
+ ep_out->ep_info2 = cpu_to_le32(EP_TYPE(BULK_OUT_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
+ ep_out->deq = cpu_to_le64(xdbc.out_seg.dma | xdbc.out_ring.cycle_state);
+
+ /* Populate bulk in endpoint context: */
+ ep_in = (struct xdbc_ep_context *)&ctx->in;
+
+ ep_in->ep_info1 = 0;
+ ep_in->ep_info2 = cpu_to_le32(EP_TYPE(BULK_IN_EP) | MAX_PACKET(1024) | MAX_BURST(max_burst));
+ ep_in->deq = cpu_to_le64(xdbc.in_seg.dma | xdbc.in_ring.cycle_state);
+
+ /* Set DbC context and info registers: */
+ xdbc_write64(xdbc.dbcc_dma, &xdbc.xdbc_reg->dccp);
+
+ dev_info = cpu_to_le32((XDBC_VENDOR_ID << 16) | XDBC_PROTOCOL);
+ writel(dev_info, &xdbc.xdbc_reg->devinfo1);
+
+ dev_info = cpu_to_le32((XDBC_DEVICE_REV << 16) | XDBC_PRODUCT_ID);
+ writel(dev_info, &xdbc.xdbc_reg->devinfo2);
+
+ xdbc.in_buf = xdbc.out_buf + XDBC_MAX_PACKET;
+ xdbc.in_dma = xdbc.out_dma + XDBC_MAX_PACKET;
+}
+
+static void xdbc_do_reset_debug_port(u32 id, u32 count)
+{
+ void __iomem *ops_reg;
+ void __iomem *portsc;
+ u32 val, cap_length;
+ int i;
+
+ cap_length = readl(xdbc.xhci_base) & 0xff;
+ ops_reg = xdbc.xhci_base + cap_length;
+
+ id--;
+ for (i = id; i < (id + count); i++) {
+ portsc = ops_reg + 0x400 + i * 0x10;
+ val = readl(portsc);
+ if (!(val & PORT_CONNECT))
+ writel(val | PORT_RESET, portsc);
+ }
+}
+
+static void xdbc_reset_debug_port(void)
+{
+ u32 val, port_offset, port_count;
+ int offset = 0;
+
+ do {
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, offset, XHCI_EXT_CAPS_PROTOCOL);
+ if (!offset)
+ break;
+
+ val = readl(xdbc.xhci_base + offset);
+ if (XHCI_EXT_PORT_MAJOR(val) != 0x3)
+ continue;
+
+ val = readl(xdbc.xhci_base + offset + 8);
+ port_offset = XHCI_EXT_PORT_OFF(val);
+ port_count = XHCI_EXT_PORT_COUNT(val);
+
+ xdbc_do_reset_debug_port(port_offset, port_count);
+ } while (1);
+}
+
+static void
+xdbc_queue_trb(struct xdbc_ring *ring, u32 field1, u32 field2, u32 field3, u32 field4)
+{
+ struct xdbc_trb *trb, *link_trb;
+
+ trb = ring->enqueue;
+ trb->field[0] = cpu_to_le32(field1);
+ trb->field[1] = cpu_to_le32(field2);
+ trb->field[2] = cpu_to_le32(field3);
+ trb->field[3] = cpu_to_le32(field4);
+
+ ++(ring->enqueue);
+ if (ring->enqueue >= &ring->segment->trbs[TRBS_PER_SEGMENT - 1]) {
+ link_trb = ring->enqueue;
+ if (ring->cycle_state)
+ link_trb->field[3] |= cpu_to_le32(TRB_CYCLE);
+ else
+ link_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+ ring->enqueue = ring->segment->trbs;
+ ring->cycle_state ^= 1;
+ }
+}
+
+static void xdbc_ring_doorbell(int target)
+{
+ writel(DOOR_BELL_TARGET(target), &xdbc.xdbc_reg->doorbell);
+}
+
+static int xdbc_start(void)
+{
+ u32 ctrl, status;
+ int ret;
+
+ ctrl = readl(&xdbc.xdbc_reg->control);
+ writel(ctrl | CTRL_DBC_ENABLE | CTRL_PORT_ENABLE, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, CTRL_DBC_ENABLE, 100000, 100);
+ if (ret) {
+ xdbc_trace("failed to initialize hardware\n");
+ return ret;
+ }
+
+ /* Reset port to avoid bus hang: */
+ if (xdbc.vendor == PCI_VENDOR_ID_INTEL)
+ xdbc_reset_debug_port();
+
+ /* Wait for port connection: */
+ ret = handshake(&xdbc.xdbc_reg->portsc, PORTSC_CONN_STATUS, PORTSC_CONN_STATUS, 5000000, 100);
+ if (ret) {
+ xdbc_trace("waiting for connection timed out\n");
+ return ret;
+ }
+
+ /* Wait for debug device to be configured: */
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_RUN, CTRL_DBC_RUN, 5000000, 100);
+ if (ret) {
+ xdbc_trace("waiting for device configuration timed out\n");
+ return ret;
+ }
+
+ /* Check port number: */
+ status = readl(&xdbc.xdbc_reg->status);
+ if (!DCST_DEBUG_PORT(status)) {
+ xdbc_trace("invalid root hub port number\n");
+ return -ENODEV;
+ }
+
+ xdbc.port_number = DCST_DEBUG_PORT(status);
+
+ xdbc_trace("DbC is running now, control 0x%08x port ID %d\n",
+ readl(&xdbc.xdbc_reg->control), xdbc.port_number);
+
+ return 0;
+}
+
+static int xdbc_bulk_transfer(void *data, int size, bool read)
+{
+ struct xdbc_ring *ring;
+ struct xdbc_trb *trb;
+ u32 length, control;
+ u32 cycle;
+ u64 addr;
+
+ if (size > XDBC_MAX_PACKET) {
+ xdbc_trace("bad parameter, size %d\n", size);
+ return -EINVAL;
+ }
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED) ||
+ !(xdbc.flags & XDBC_FLAGS_CONFIGURED) ||
+ (!read && (xdbc.flags & XDBC_FLAGS_OUT_STALL)) ||
+ (read && (xdbc.flags & XDBC_FLAGS_IN_STALL))) {
+
+ xdbc_trace("connection not ready, flags %08x\n", xdbc.flags);
+ return -EIO;
+ }
+
+ ring = (read ? &xdbc.in_ring : &xdbc.out_ring);
+ trb = ring->enqueue;
+ cycle = ring->cycle_state;
+ length = TRB_LEN(size);
+ control = TRB_TYPE(TRB_NORMAL) | TRB_IOC;
+
+ if (cycle)
+ control &= cpu_to_le32(~TRB_CYCLE);
+ else
+ control |= cpu_to_le32(TRB_CYCLE);
+
+ if (read) {
+ memset(xdbc.in_buf, 0, XDBC_MAX_PACKET);
+ addr = xdbc.in_dma;
+ xdbc.flags |= XDBC_FLAGS_IN_PROCESS;
+ } else {
+ memset(xdbc.out_buf, 0, XDBC_MAX_PACKET);
+ memcpy(xdbc.out_buf, data, size);
+ addr = xdbc.out_dma;
+ xdbc.flags |= XDBC_FLAGS_OUT_PROCESS;
+ }
+
+ xdbc_queue_trb(ring, lower_32_bits(addr), upper_32_bits(addr), length, control);
+
+ /*
+ * Add a barrier between writes of trb fields and flipping
+ * the cycle bit:
+ */
+ wmb();
+ if (cycle)
+ trb->field[3] |= cpu_to_le32(cycle);
+ else
+ trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+ xdbc_ring_doorbell(read ? IN_EP_DOORBELL : OUT_EP_DOORBELL);
+
+ return size;
+}
+
+static int xdbc_handle_external_reset(void)
+{
+ int ret = 0;
+
+ xdbc.flags = 0;
+ writel(0, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 10);
+ if (ret)
+ goto reset_out;
+
+ xdbc_mem_init();
+
+ mmiowb();
+
+ ret = xdbc_start();
+ if (ret < 0)
+ goto reset_out;
+
+ xdbc_trace("dbc recovered\n");
+
+ xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
+
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+
+ return 0;
+
+reset_out:
+ xdbc_trace("failed to recover from external reset\n");
+ return ret;
+}
+
+static int __init xdbc_early_setup(void)
+{
+ int ret;
+
+ writel(0, &xdbc.xdbc_reg->control);
+ ret = handshake(&xdbc.xdbc_reg->control, CTRL_DBC_ENABLE, 0, 100000, 100);
+ if (ret)
+ return ret;
+
+ /* Allocate the table page: */
+ xdbc.table_base = xdbc_get_page(&xdbc.table_dma);
+ if (!xdbc.table_base)
+ return -ENOMEM;
+
+ /* Get and store the transfer buffer: */
+ xdbc.out_buf = xdbc_get_page(&xdbc.out_dma);
+ if (!xdbc.out_buf)
+ return -ENOMEM;
+
+ /* Allocate the event ring: */
+ ret = xdbc_alloc_ring(&xdbc.evt_seg, &xdbc.evt_ring);
+ if (ret < 0)
+ return ret;
+
+ /* Allocate IN/OUT endpoint transfer rings: */
+ ret = xdbc_alloc_ring(&xdbc.in_seg, &xdbc.in_ring);
+ if (ret < 0)
+ return ret;
+
+ ret = xdbc_alloc_ring(&xdbc.out_seg, &xdbc.out_ring);
+ if (ret < 0)
+ return ret;
+
+ xdbc_mem_init();
+
+ mmiowb();
+
+ ret = xdbc_start();
+ if (ret < 0) {
+ writel(0, &xdbc.xdbc_reg->control);
+ return ret;
+ }
+
+ xdbc.flags |= XDBC_FLAGS_INITIALIZED | XDBC_FLAGS_CONFIGURED;
+
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+
+ return 0;
+}
+
+int __init early_xdbc_parse_parameter(char *s)
+{
+ unsigned long dbgp_num = 0;
+ u32 bus, dev, func, offset;
+ int ret;
+
+ if (!early_pci_allowed())
+ return -EPERM;
+
+ if (strstr(s, "keep"))
+ early_console_keep = true;
+
+ if (xdbc.xdbc_reg)
+ return 0;
+
+ if (*s && kstrtoul(s, 0, &dbgp_num))
+ dbgp_num = 0;
+
+ pr_notice("dbgp_num: %lu\n", dbgp_num);
+
+ /* Locate the host controller: */
+ ret = xdbc_find_dbgp(dbgp_num, &bus, &dev, &func);
+ if (ret) {
+ pr_notice("failed to locate xhci host\n");
+ return -ENODEV;
+ }
+
+ xdbc.vendor = read_pci_config_16(bus, dev, func, PCI_VENDOR_ID);
+ xdbc.device = read_pci_config_16(bus, dev, func, PCI_DEVICE_ID);
+ xdbc.bus = bus;
+ xdbc.dev = dev;
+ xdbc.func = func;
+
+ /* Map the IO memory: */
+ xdbc.xhci_base = xdbc_map_pci_mmio(bus, dev, func);
+ if (!xdbc.xhci_base)
+ return -EINVAL;
+
+ /* Locate DbC registers: */
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
+ if (!offset) {
+ pr_notice("xhci host doesn't support debug capability\n");
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+ xdbc.xhci_base = NULL;
+ xdbc.xhci_length = 0;
+
+ return -ENODEV;
+ }
+ xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
+
+ return 0;
+}
+
+int __init early_xdbc_setup_hardware(void)
+{
+ int ret;
+
+ if (!xdbc.xdbc_reg)
+ return -ENODEV;
+
+ xdbc_bios_handoff();
+
+ raw_spin_lock_init(&xdbc.lock);
+
+ ret = xdbc_early_setup();
+ if (ret) {
+ pr_notice("failed to setup the connection to host\n");
+
+ xdbc_free_ring(&xdbc.evt_ring);
+ xdbc_free_ring(&xdbc.out_ring);
+ xdbc_free_ring(&xdbc.in_ring);
+
+ if (xdbc.table_dma)
+ free_bootmem(xdbc.table_dma, PAGE_SIZE);
+
+ if (xdbc.out_dma)
+ free_bootmem(xdbc.out_dma, PAGE_SIZE);
+
+ xdbc.table_base = NULL;
+ xdbc.out_buf = NULL;
+ }
+
+ return ret;
+}
+
+static void xdbc_handle_port_status(struct xdbc_trb *evt_trb)
+{
+ u32 port_reg;
+
+ port_reg = readl(&xdbc.xdbc_reg->portsc);
+ if (port_reg & PORTSC_CONN_CHANGE) {
+ xdbc_trace("connect status change event\n");
+
+ /* Check whether cable unplugged: */
+ if (!(port_reg & PORTSC_CONN_STATUS)) {
+ xdbc.flags = 0;
+ xdbc_trace("cable unplugged\n");
+ }
+ }
+
+ if (port_reg & PORTSC_RESET_CHANGE)
+ xdbc_trace("port reset change event\n");
+
+ if (port_reg & PORTSC_LINK_CHANGE)
+ xdbc_trace("port link status change event\n");
+
+ if (port_reg & PORTSC_CONFIG_CHANGE)
+ xdbc_trace("config error change\n");
+
+ /* Write back the value to clear RW1C bits: */
+ writel(port_reg, &xdbc.xdbc_reg->portsc);
+}
+
+static void xdbc_handle_tx_event(struct xdbc_trb *evt_trb)
+{
+ size_t remain_length;
+ u32 comp_code;
+ int ep_id;
+
+ comp_code = GET_COMP_CODE(le32_to_cpu(evt_trb->field[2]));
+ remain_length = EVENT_TRB_LEN(le32_to_cpu(evt_trb->field[2]));
+ ep_id = TRB_TO_EP_ID(le32_to_cpu(evt_trb->field[3]));
+
+ switch (comp_code) {
+ case COMP_SUCCESS:
+ remain_length = 0;
+ case COMP_SHORT_PACKET:
+ break;
+ case COMP_TRB_ERROR:
+ case COMP_BABBLE_DETECTED_ERROR:
+ case COMP_USB_TRANSACTION_ERROR:
+ case COMP_STALL_ERROR:
+ default:
+ if (ep_id == XDBC_EPID_OUT)
+ xdbc.flags |= XDBC_FLAGS_OUT_STALL;
+ if (ep_id == XDBC_EPID_IN)
+ xdbc.flags |= XDBC_FLAGS_IN_STALL;
+
+ xdbc_trace("endpoint %d stalled\n", ep_id);
+ break;
+ }
+
+ if (ep_id == XDBC_EPID_IN) {
+ xdbc.flags &= ~XDBC_FLAGS_IN_PROCESS;
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+ } else if (ep_id == XDBC_EPID_OUT) {
+ xdbc.flags &= ~XDBC_FLAGS_OUT_PROCESS;
+ } else {
+ xdbc_trace("invalid endpoint id %d\n", ep_id);
+ }
+}
+
+static void xdbc_handle_events(void)
+{
+ struct xdbc_trb *evt_trb;
+ bool update_erdp = false;
+ u32 reg;
+ u8 cmd;
+
+ cmd = read_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND);
+ if (!(cmd & PCI_COMMAND_MASTER)) {
+ cmd |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
+ write_pci_config_byte(xdbc.bus, xdbc.dev, xdbc.func, PCI_COMMAND, cmd);
+ }
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
+ return;
+
+ /* Handle external reset events: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (!(reg & CTRL_DBC_ENABLE)) {
+ if (xdbc_handle_external_reset()) {
+ xdbc_trace("failed to recover connection\n");
+ return;
+ }
+ }
+
+ /* Handle configure-exit event: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (reg & CTRL_DBC_RUN_CHANGE) {
+ writel(reg, &xdbc.xdbc_reg->control);
+ if (reg & CTRL_DBC_RUN)
+ xdbc.flags |= XDBC_FLAGS_CONFIGURED;
+ else
+ xdbc.flags &= ~XDBC_FLAGS_CONFIGURED;
+ }
+
+ /* Handle endpoint stall event: */
+ reg = readl(&xdbc.xdbc_reg->control);
+ if (reg & CTRL_HALT_IN_TR) {
+ xdbc.flags |= XDBC_FLAGS_IN_STALL;
+ } else {
+ xdbc.flags &= ~XDBC_FLAGS_IN_STALL;
+ if (!(xdbc.flags & XDBC_FLAGS_IN_PROCESS))
+ xdbc_bulk_transfer(NULL, XDBC_MAX_PACKET, true);
+ }
+
+ if (reg & CTRL_HALT_OUT_TR)
+ xdbc.flags |= XDBC_FLAGS_OUT_STALL;
+ else
+ xdbc.flags &= ~XDBC_FLAGS_OUT_STALL;
+
+ /* Handle the events in the event ring: */
+ evt_trb = xdbc.evt_ring.dequeue;
+ while ((le32_to_cpu(evt_trb->field[3]) & TRB_CYCLE) == xdbc.evt_ring.cycle_state) {
+ /*
+ * Add a barrier between reading the cycle flag and any
+ * reads of the event's flags/data below:
+ */
+ rmb();
+
+ switch ((le32_to_cpu(evt_trb->field[3]) & TRB_TYPE_BITMASK)) {
+ case TRB_TYPE(TRB_PORT_STATUS):
+ xdbc_handle_port_status(evt_trb);
+ break;
+ case TRB_TYPE(TRB_TRANSFER):
+ xdbc_handle_tx_event(evt_trb);
+ break;
+ default:
+ break;
+ }
+
+ ++(xdbc.evt_ring.dequeue);
+ if (xdbc.evt_ring.dequeue == &xdbc.evt_seg.trbs[TRBS_PER_SEGMENT]) {
+ xdbc.evt_ring.dequeue = xdbc.evt_seg.trbs;
+ xdbc.evt_ring.cycle_state ^= 1;
+ }
+
+ evt_trb = xdbc.evt_ring.dequeue;
+ update_erdp = true;
+ }
+
+ /* Update event ring dequeue pointer: */
+ if (update_erdp)
+ xdbc_write64(__pa(xdbc.evt_ring.dequeue), &xdbc.xdbc_reg->erdp);
+}
+
+static int xdbc_bulk_write(const char *bytes, int size)
+{
+ int ret, timeout = 0;
+ unsigned long flags;
+
+retry:
+ if (in_nmi()) {
+ if (!raw_spin_trylock_irqsave(&xdbc.lock, flags))
+ return -EAGAIN;
+ } else {
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ }
+
+ xdbc_handle_events();
+
+ /* Check completion of the previous request: */
+ if ((xdbc.flags & XDBC_FLAGS_OUT_PROCESS) && (timeout < 2000000)) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ udelay(100);
+ timeout += 100;
+ goto retry;
+ }
+
+ if (xdbc.flags & XDBC_FLAGS_OUT_PROCESS) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ xdbc_trace("previous transfer not completed yet\n");
+
+ return -ETIMEDOUT;
+ }
+
+ ret = xdbc_bulk_transfer((void *)bytes, size, false);
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+
+ return ret;
+}
+
+static void early_xdbc_write(struct console *con, const char *str, u32 n)
+{
+ static char buf[XDBC_MAX_PACKET];
+ int chunk, ret;
+ int use_cr = 0;
+
+ if (!xdbc.xdbc_reg)
+ return;
+ memset(buf, 0, XDBC_MAX_PACKET);
+ while (n > 0) {
+ for (chunk = 0; chunk < XDBC_MAX_PACKET && n > 0; str++, chunk++, n--) {
+
+ if (!use_cr && *str == '\n') {
+ use_cr = 1;
+ buf[chunk] = '\r';
+ str--;
+ n++;
+ continue;
+ }
+
+ if (use_cr)
+ use_cr = 0;
+ buf[chunk] = *str;
+ }
+
+ if (chunk > 0) {
+ ret = xdbc_bulk_write(buf, chunk);
+ if (ret < 0)
+ xdbc_trace("missed message {%s}\n", buf);
+ }
+ }
+}
+
+static struct console early_xdbc_console = {
+ .name = "earlyxdbc",
+ .write = early_xdbc_write,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+};
+
+void __init early_xdbc_register_console(void)
+{
+ if (early_console)
+ return;
+
+ early_console = &early_xdbc_console;
+ if (early_console_keep)
+ early_console->flags &= ~CON_BOOT;
+ else
+ early_console->flags |= CON_BOOT;
+ register_console(early_console);
+}
+
+static void xdbc_unregister_console(void)
+{
+ if (early_xdbc_console.flags & CON_ENABLED)
+ unregister_console(&early_xdbc_console);
+}
+
+static int xdbc_scrub_function(void *ptr)
+{
+ unsigned long flags;
+
+ while (true) {
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ xdbc_handle_events();
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED)) {
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ break;
+ }
+
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+ schedule_timeout_interruptible(1);
+ }
+
+ xdbc_unregister_console();
+ writel(0, &xdbc.xdbc_reg->control);
+ xdbc_trace("dbc scrub function exits\n");
+
+ return 0;
+}
+
+static int __init xdbc_init(void)
+{
+ unsigned long flags;
+ void __iomem *base;
+ int ret = 0;
+ u32 offset;
+
+ if (!(xdbc.flags & XDBC_FLAGS_INITIALIZED))
+ return 0;
+
+ /*
+ * It's time to shut down the DbC, so that the debug
+ * port can be reused by the host controller:
+ */
+ if (early_xdbc_console.index == -1 ||
+ (early_xdbc_console.flags & CON_BOOT)) {
+ xdbc_trace("hardware not used anymore\n");
+ goto free_and_quit;
+ }
+
+ base = ioremap_nocache(xdbc.xhci_start, xdbc.xhci_length);
+ if (!base) {
+ xdbc_trace("failed to remap the io address\n");
+ ret = -ENOMEM;
+ goto free_and_quit;
+ }
+
+ raw_spin_lock_irqsave(&xdbc.lock, flags);
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+ xdbc.xhci_base = base;
+ offset = xhci_find_next_ext_cap(xdbc.xhci_base, 0, XHCI_EXT_CAPS_DEBUG);
+ xdbc.xdbc_reg = (struct xdbc_regs __iomem *)(xdbc.xhci_base + offset);
+ raw_spin_unlock_irqrestore(&xdbc.lock, flags);
+
+ kthread_run(xdbc_scrub_function, NULL, "%s", "xdbc");
+
+ return 0;
+
+free_and_quit:
+ xdbc_free_ring(&xdbc.evt_ring);
+ xdbc_free_ring(&xdbc.out_ring);
+ xdbc_free_ring(&xdbc.in_ring);
+ free_bootmem(xdbc.table_dma, PAGE_SIZE);
+ free_bootmem(xdbc.out_dma, PAGE_SIZE);
+ writel(0, &xdbc.xdbc_reg->control);
+ early_iounmap(xdbc.xhci_base, xdbc.xhci_length);
+
+ return ret;
+}
+subsys_initcall(xdbc_init);
diff --git a/drivers/usb/early/xhci-dbc.h b/drivers/usb/early/xhci-dbc.h
new file mode 100644
index 0000000..673686e
--- /dev/null
+++ b/drivers/usb/early/xhci-dbc.h
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * xhci-dbc.h - xHCI debug capability early driver
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ */
+
+#ifndef __LINUX_XHCI_DBC_H
+#define __LINUX_XHCI_DBC_H
+
+#include <linux/types.h>
+#include <linux/usb/ch9.h>
+
+/*
+ * xHCI Debug Capability Register interfaces:
+ */
+struct xdbc_regs {
+ __le32 capability;
+ __le32 doorbell;
+ __le32 ersts; /* Event Ring Segment Table Size*/
+ __le32 __reserved_0; /* 0c~0f reserved bits */
+ __le64 erstba; /* Event Ring Segment Table Base Address */
+ __le64 erdp; /* Event Ring Dequeue Pointer */
+ __le32 control;
+ __le32 status;
+ __le32 portsc; /* Port status and control */
+ __le32 __reserved_1; /* 2b~28 reserved bits */
+ __le64 dccp; /* Debug Capability Context Pointer */
+ __le32 devinfo1; /* Device Descriptor Info Register 1 */
+ __le32 devinfo2; /* Device Descriptor Info Register 2 */
+};
+
+#define DEBUG_MAX_BURST(p) (((p) >> 16) & 0xff)
+
+#define CTRL_DBC_RUN BIT(0)
+#define CTRL_PORT_ENABLE BIT(1)
+#define CTRL_HALT_OUT_TR BIT(2)
+#define CTRL_HALT_IN_TR BIT(3)
+#define CTRL_DBC_RUN_CHANGE BIT(4)
+#define CTRL_DBC_ENABLE BIT(31)
+
+#define DCST_DEBUG_PORT(p) (((p) >> 24) & 0xff)
+
+#define PORTSC_CONN_STATUS BIT(0)
+#define PORTSC_CONN_CHANGE BIT(17)
+#define PORTSC_RESET_CHANGE BIT(21)
+#define PORTSC_LINK_CHANGE BIT(22)
+#define PORTSC_CONFIG_CHANGE BIT(23)
+
+/*
+ * xHCI Debug Capability data structures:
+ */
+struct xdbc_trb {
+ __le32 field[4];
+};
+
+struct xdbc_erst_entry {
+ __le64 seg_addr;
+ __le32 seg_size;
+ __le32 __reserved_0;
+};
+
+struct xdbc_info_context {
+ __le64 string0;
+ __le64 manufacturer;
+ __le64 product;
+ __le64 serial;
+ __le32 length;
+ __le32 __reserved_0[7];
+};
+
+struct xdbc_ep_context {
+ __le32 ep_info1;
+ __le32 ep_info2;
+ __le64 deq;
+ __le32 tx_info;
+ __le32 __reserved_0[11];
+};
+
+struct xdbc_context {
+ struct xdbc_info_context info;
+ struct xdbc_ep_context out;
+ struct xdbc_ep_context in;
+};
+
+#define XDBC_INFO_CONTEXT_SIZE 48
+#define XDBC_MAX_STRING_LENGTH 64
+#define XDBC_STRING_MANUFACTURER "Linux Foundation"
+#define XDBC_STRING_PRODUCT "Linux USB GDB Target"
+#define XDBC_STRING_SERIAL "0001"
+
+struct xdbc_strings {
+ char string0[XDBC_MAX_STRING_LENGTH];
+ char manufacturer[XDBC_MAX_STRING_LENGTH];
+ char product[XDBC_MAX_STRING_LENGTH];
+ char serial[XDBC_MAX_STRING_LENGTH];
+};
+
+#define XDBC_PROTOCOL 1 /* GNU Remote Debug Command Set */
+#define XDBC_VENDOR_ID 0x1d6b /* Linux Foundation 0x1d6b */
+#define XDBC_PRODUCT_ID 0x0011 /* __le16 idProduct; device 0011 */
+#define XDBC_DEVICE_REV 0x0010 /* 0.10 */
+
+/*
+ * xHCI Debug Capability software state structures:
+ */
+struct xdbc_segment {
+ struct xdbc_trb *trbs;
+ dma_addr_t dma;
+};
+
+#define XDBC_TRBS_PER_SEGMENT 256
+
+struct xdbc_ring {
+ struct xdbc_segment *segment;
+ struct xdbc_trb *enqueue;
+ struct xdbc_trb *dequeue;
+ u32 cycle_state;
+};
+
+#define XDBC_EPID_OUT 2
+#define XDBC_EPID_IN 3
+
+struct xdbc_state {
+ u16 vendor;
+ u16 device;
+ u32 bus;
+ u32 dev;
+ u32 func;
+ void __iomem *xhci_base;
+ u64 xhci_start;
+ size_t xhci_length;
+ int port_number;
+
+ /* DbC register base */
+ struct xdbc_regs __iomem *xdbc_reg;
+
+ /* DbC table page */
+ dma_addr_t table_dma;
+ void *table_base;
+
+ /* event ring segment table */
+ dma_addr_t erst_dma;
+ size_t erst_size;
+ void *erst_base;
+
+ /* event ring segments */
+ struct xdbc_ring evt_ring;
+ struct xdbc_segment evt_seg;
+
+ /* debug capability contexts */
+ dma_addr_t dbcc_dma;
+ size_t dbcc_size;
+ void *dbcc_base;
+
+ /* descriptor strings */
+ dma_addr_t string_dma;
+ size_t string_size;
+ void *string_base;
+
+ /* bulk OUT endpoint */
+ struct xdbc_ring out_ring;
+ struct xdbc_segment out_seg;
+ void *out_buf;
+ dma_addr_t out_dma;
+
+ /* bulk IN endpoint */
+ struct xdbc_ring in_ring;
+ struct xdbc_segment in_seg;
+ void *in_buf;
+ dma_addr_t in_dma;
+
+ u32 flags;
+
+ /* spinlock for early_xdbc_write() reentrancy */
+ raw_spinlock_t lock;
+};
+
+#define XDBC_PCI_MAX_BUSES 256
+#define XDBC_PCI_MAX_DEVICES 32
+#define XDBC_PCI_MAX_FUNCTION 8
+
+#define XDBC_TABLE_ENTRY_SIZE 64
+#define XDBC_ERST_ENTRY_NUM 1
+#define XDBC_DBCC_ENTRY_NUM 3
+#define XDBC_STRING_ENTRY_NUM 4
+
+/* Bits definitions for xdbc_state.flags: */
+#define XDBC_FLAGS_INITIALIZED BIT(0)
+#define XDBC_FLAGS_IN_STALL BIT(1)
+#define XDBC_FLAGS_OUT_STALL BIT(2)
+#define XDBC_FLAGS_IN_PROCESS BIT(3)
+#define XDBC_FLAGS_OUT_PROCESS BIT(4)
+#define XDBC_FLAGS_CONFIGURED BIT(5)
+
+#define XDBC_MAX_PACKET 1024
+
+/* Door bell target: */
+#define OUT_EP_DOORBELL 0
+#define IN_EP_DOORBELL 1
+#define DOOR_BELL_TARGET(p) (((p) & 0xff) << 8)
+
+#define xdbc_read64(regs) xhci_read_64(NULL, (regs))
+#define xdbc_write64(val, regs) xhci_write_64(NULL, (val), (regs))
+
+#endif /* __LINUX_XHCI_DBC_H */