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-rw-r--r--drivers/staging/android/fiq_debugger/Kconfig58
-rw-r--r--drivers/staging/android/fiq_debugger/Makefile4
-rw-r--r--drivers/staging/android/fiq_debugger/fiq_debugger.c1248
-rw-r--r--drivers/staging/android/fiq_debugger/fiq_debugger.h64
-rw-r--r--drivers/staging/android/fiq_debugger/fiq_debugger_arm.c240
-rw-r--r--drivers/staging/android/fiq_debugger/fiq_debugger_arm64.c202
-rw-r--r--drivers/staging/android/fiq_debugger/fiq_debugger_priv.h37
-rw-r--r--drivers/staging/android/fiq_debugger/fiq_debugger_ringbuf.h94
-rw-r--r--drivers/staging/android/fiq_debugger/fiq_watchdog.c56
-rw-r--r--drivers/staging/android/fiq_debugger/fiq_watchdog.h20
10 files changed, 2023 insertions, 0 deletions
diff --git a/drivers/staging/android/fiq_debugger/Kconfig b/drivers/staging/android/fiq_debugger/Kconfig
new file mode 100644
index 000000000000..60fc224d4efc
--- /dev/null
+++ b/drivers/staging/android/fiq_debugger/Kconfig
@@ -0,0 +1,58 @@
+config FIQ_DEBUGGER
+ bool "FIQ Mode Serial Debugger"
+ default n
+ depends on ARM || ARM64
+ help
+ The FIQ serial debugger can accept commands even when the
+ kernel is unresponsive due to being stuck with interrupts
+ disabled.
+
+config FIQ_DEBUGGER_NO_SLEEP
+ bool "Keep serial debugger active"
+ depends on FIQ_DEBUGGER
+ default n
+ help
+ Enables the serial debugger at boot. Passing
+ fiq_debugger.no_sleep on the kernel commandline will
+ override this config option.
+
+config FIQ_DEBUGGER_WAKEUP_IRQ_ALWAYS_ON
+ bool "Don't disable wakeup IRQ when debugger is active"
+ depends on FIQ_DEBUGGER
+ default n
+ help
+ Don't disable the wakeup irq when enabling the uart clock. This will
+ cause extra interrupts, but it makes the serial debugger usable with
+ on some MSM radio builds that ignore the uart clock request in power
+ collapse.
+
+config FIQ_DEBUGGER_CONSOLE
+ bool "Console on FIQ Serial Debugger port"
+ depends on FIQ_DEBUGGER
+ default n
+ help
+ Enables a console so that printk messages are displayed on
+ the debugger serial port as the occur.
+
+config FIQ_DEBUGGER_CONSOLE_DEFAULT_ENABLE
+ bool "Put the FIQ debugger into console mode by default"
+ depends on FIQ_DEBUGGER_CONSOLE
+ default n
+ help
+ If enabled, this puts the fiq debugger into console mode by default.
+ Otherwise, the fiq debugger will start out in debug mode.
+
+config FIQ_DEBUGGER_UART_OVERLAY
+ bool "Install uart DT overlay"
+ depends on FIQ_DEBUGGER
+ select OF_OVERLAY
+ default n
+ help
+ If enabled, fiq debugger is calling fiq_debugger_uart_overlay()
+ that will apply overlay uart_overlay@0 to disable proper uart.
+
+config FIQ_WATCHDOG
+ bool
+ select FIQ_DEBUGGER
+ select PSTORE_RAM
+ default n
diff --git a/drivers/staging/android/fiq_debugger/Makefile b/drivers/staging/android/fiq_debugger/Makefile
new file mode 100644
index 000000000000..a7ca4871cad3
--- /dev/null
+++ b/drivers/staging/android/fiq_debugger/Makefile
@@ -0,0 +1,4 @@
+obj-y += fiq_debugger.o
+obj-$(CONFIG_ARM) += fiq_debugger_arm.o
+obj-$(CONFIG_ARM64) += fiq_debugger_arm64.o
+obj-$(CONFIG_FIQ_WATCHDOG) += fiq_watchdog.o
diff --git a/drivers/staging/android/fiq_debugger/fiq_debugger.c b/drivers/staging/android/fiq_debugger/fiq_debugger.c
new file mode 100644
index 000000000000..b132cff14f01
--- /dev/null
+++ b/drivers/staging/android/fiq_debugger/fiq_debugger.c
@@ -0,0 +1,1248 @@
+/*
+ * drivers/staging/android/fiq_debugger.c
+ *
+ * Serial Debugger Interface accessed through an FIQ interrupt.
+ *
+ * Copyright (C) 2008 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <stdarg.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/console.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/kernel_stat.h>
+#include <linux/kmsg_dump.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/timer.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/wakelock.h>
+
+#ifdef CONFIG_FIQ_GLUE
+#include <asm/fiq_glue.h>
+#endif
+
+#ifdef CONFIG_FIQ_DEBUGGER_UART_OVERLAY
+#include <linux/of.h>
+#endif
+
+#include <linux/uaccess.h>
+
+#include "fiq_debugger.h"
+#include "fiq_debugger_priv.h"
+#include "fiq_debugger_ringbuf.h"
+
+#define DEBUG_MAX 64
+#define MAX_UNHANDLED_FIQ_COUNT 1000000
+
+#define MAX_FIQ_DEBUGGER_PORTS 4
+
+struct fiq_debugger_state {
+#ifdef CONFIG_FIQ_GLUE
+ struct fiq_glue_handler handler;
+#endif
+ struct fiq_debugger_output output;
+
+ int fiq;
+ int uart_irq;
+ int signal_irq;
+ int wakeup_irq;
+ bool wakeup_irq_no_set_wake;
+ struct clk *clk;
+ struct fiq_debugger_pdata *pdata;
+ struct platform_device *pdev;
+
+ char debug_cmd[DEBUG_MAX];
+ int debug_busy;
+ int debug_abort;
+
+ char debug_buf[DEBUG_MAX];
+ int debug_count;
+
+ bool no_sleep;
+ bool debug_enable;
+ bool ignore_next_wakeup_irq;
+ struct timer_list sleep_timer;
+ spinlock_t sleep_timer_lock;
+ bool uart_enabled;
+ struct wake_lock debugger_wake_lock;
+ bool console_enable;
+ int current_cpu;
+ atomic_t unhandled_fiq_count;
+ bool in_fiq;
+
+ struct work_struct work;
+ spinlock_t work_lock;
+ char work_cmd[DEBUG_MAX];
+
+#ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
+ spinlock_t console_lock;
+ struct console console;
+ struct tty_port tty_port;
+ struct fiq_debugger_ringbuf *tty_rbuf;
+ bool syslog_dumping;
+#endif
+
+ unsigned int last_irqs[NR_IRQS];
+ unsigned int last_local_timer_irqs[NR_CPUS];
+};
+
+#ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
+struct tty_driver *fiq_tty_driver;
+#endif
+
+#ifdef CONFIG_FIQ_DEBUGGER_NO_SLEEP
+static bool initial_no_sleep = true;
+#else
+static bool initial_no_sleep;
+#endif
+
+#ifdef CONFIG_FIQ_DEBUGGER_CONSOLE_DEFAULT_ENABLE
+static bool initial_debug_enable = true;
+static bool initial_console_enable = true;
+#else
+static bool initial_debug_enable;
+static bool initial_console_enable;
+#endif
+
+static bool fiq_kgdb_enable;
+static bool fiq_debugger_disable;
+
+module_param_named(no_sleep, initial_no_sleep, bool, 0644);
+module_param_named(debug_enable, initial_debug_enable, bool, 0644);
+module_param_named(console_enable, initial_console_enable, bool, 0644);
+module_param_named(kgdb_enable, fiq_kgdb_enable, bool, 0644);
+module_param_named(disable, fiq_debugger_disable, bool, 0644);
+
+#ifdef CONFIG_FIQ_DEBUGGER_WAKEUP_IRQ_ALWAYS_ON
+static inline
+void fiq_debugger_enable_wakeup_irq(struct fiq_debugger_state *state) {}
+static inline
+void fiq_debugger_disable_wakeup_irq(struct fiq_debugger_state *state) {}
+#else
+static inline
+void fiq_debugger_enable_wakeup_irq(struct fiq_debugger_state *state)
+{
+ if (state->wakeup_irq < 0)
+ return;
+ enable_irq(state->wakeup_irq);
+ if (!state->wakeup_irq_no_set_wake)
+ enable_irq_wake(state->wakeup_irq);
+}
+static inline
+void fiq_debugger_disable_wakeup_irq(struct fiq_debugger_state *state)
+{
+ if (state->wakeup_irq < 0)
+ return;
+ disable_irq_nosync(state->wakeup_irq);
+ if (!state->wakeup_irq_no_set_wake)
+ disable_irq_wake(state->wakeup_irq);
+}
+#endif
+
+static inline bool fiq_debugger_have_fiq(struct fiq_debugger_state *state)
+{
+ return (state->fiq >= 0);
+}
+
+#ifdef CONFIG_FIQ_GLUE
+static void fiq_debugger_force_irq(struct fiq_debugger_state *state)
+{
+ unsigned int irq = state->signal_irq;
+
+ if (WARN_ON(!fiq_debugger_have_fiq(state)))
+ return;
+ if (state->pdata->force_irq) {
+ state->pdata->force_irq(state->pdev, irq);
+ } else {
+ struct irq_chip *chip = irq_get_chip(irq);
+ if (chip && chip->irq_retrigger)
+ chip->irq_retrigger(irq_get_irq_data(irq));
+ }
+}
+#endif
+
+static void fiq_debugger_uart_enable(struct fiq_debugger_state *state)
+{
+ if (state->clk)
+ clk_enable(state->clk);
+ if (state->pdata->uart_enable)
+ state->pdata->uart_enable(state->pdev);
+}
+
+static void fiq_debugger_uart_disable(struct fiq_debugger_state *state)
+{
+ if (state->pdata->uart_disable)
+ state->pdata->uart_disable(state->pdev);
+ if (state->clk)
+ clk_disable(state->clk);
+}
+
+static void fiq_debugger_uart_flush(struct fiq_debugger_state *state)
+{
+ if (state->pdata->uart_flush)
+ state->pdata->uart_flush(state->pdev);
+}
+
+static void fiq_debugger_putc(struct fiq_debugger_state *state, char c)
+{
+ state->pdata->uart_putc(state->pdev, c);
+}
+
+static void fiq_debugger_puts(struct fiq_debugger_state *state, char *s)
+{
+ unsigned c;
+ while ((c = *s++)) {
+ if (c == '\n')
+ fiq_debugger_putc(state, '\r');
+ fiq_debugger_putc(state, c);
+ }
+}
+
+static void fiq_debugger_prompt(struct fiq_debugger_state *state)
+{
+ fiq_debugger_puts(state, "debug> ");
+}
+
+static void fiq_debugger_dump_kernel_log(struct fiq_debugger_state *state)
+{
+ char buf[512];
+ size_t len;
+ struct kmsg_dumper dumper = { .active = true };
+
+
+ kmsg_dump_rewind_nolock(&dumper);
+ while (kmsg_dump_get_line_nolock(&dumper, true, buf,
+ sizeof(buf) - 1, &len)) {
+ buf[len] = 0;
+ fiq_debugger_puts(state, buf);
+ }
+}
+
+static void fiq_debugger_printf(struct fiq_debugger_output *output,
+ const char *fmt, ...)
+{
+ struct fiq_debugger_state *state;
+ char buf[256];
+ va_list ap;
+
+ state = container_of(output, struct fiq_debugger_state, output);
+ va_start(ap, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, ap);
+ va_end(ap);
+
+ fiq_debugger_puts(state, buf);
+}
+
+/* Safe outside fiq context */
+static int fiq_debugger_printf_nfiq(void *cookie, const char *fmt, ...)
+{
+ struct fiq_debugger_state *state = cookie;
+ char buf[256];
+ va_list ap;
+ unsigned long irq_flags;
+
+ va_start(ap, fmt);
+ vsnprintf(buf, 128, fmt, ap);
+ va_end(ap);
+
+ local_irq_save(irq_flags);
+ fiq_debugger_puts(state, buf);
+ fiq_debugger_uart_flush(state);
+ local_irq_restore(irq_flags);
+ return state->debug_abort;
+}
+
+static void fiq_debugger_dump_irqs(struct fiq_debugger_state *state)
+{
+ int n;
+ struct irq_desc *desc;
+
+ fiq_debugger_printf(&state->output,
+ "irqnr total since-last status name\n");
+ for_each_irq_desc(n, desc) {
+ struct irqaction *act = desc->action;
+ if (!act && !kstat_irqs(n))
+ continue;
+ fiq_debugger_printf(&state->output, "%5d: %10u %11u %8x %s\n", n,
+ kstat_irqs(n),
+ kstat_irqs(n) - state->last_irqs[n],
+ desc->status_use_accessors,
+ (act && act->name) ? act->name : "???");
+ state->last_irqs[n] = kstat_irqs(n);
+ }
+}
+
+static void fiq_debugger_do_ps(struct fiq_debugger_state *state)
+{
+ struct task_struct *g;
+ struct task_struct *p;
+ unsigned task_state;
+ static const char stat_nam[] = "RSDTtZX";
+
+ fiq_debugger_printf(&state->output, "pid ppid prio task pc\n");
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ task_state = p->state ? __ffs(p->state) + 1 : 0;
+ fiq_debugger_printf(&state->output,
+ "%5d %5d %4d ", p->pid, p->parent->pid, p->prio);
+ fiq_debugger_printf(&state->output, "%-13.13s %c", p->comm,
+ task_state >= sizeof(stat_nam) ? '?' : stat_nam[task_state]);
+ if (task_state == TASK_RUNNING)
+ fiq_debugger_printf(&state->output, " running\n");
+ else
+ fiq_debugger_printf(&state->output, " %08lx\n",
+ thread_saved_pc(p));
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+}
+
+#ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
+static void fiq_debugger_begin_syslog_dump(struct fiq_debugger_state *state)
+{
+ state->syslog_dumping = true;
+}
+
+static void fiq_debugger_end_syslog_dump(struct fiq_debugger_state *state)
+{
+ state->syslog_dumping = false;
+}
+#else
+extern int do_syslog(int type, char __user *bug, int count);
+static void fiq_debugger_begin_syslog_dump(struct fiq_debugger_state *state)
+{
+ do_syslog(5 /* clear */, NULL, 0);
+}
+
+static void fiq_debugger_end_syslog_dump(struct fiq_debugger_state *state)
+{
+ fiq_debugger_dump_kernel_log(state);
+}
+#endif
+
+static void fiq_debugger_do_sysrq(struct fiq_debugger_state *state, char rq)
+{
+ if ((rq == 'g' || rq == 'G') && !fiq_kgdb_enable) {
+ fiq_debugger_printf(&state->output, "sysrq-g blocked\n");
+ return;
+ }
+ fiq_debugger_begin_syslog_dump(state);
+ handle_sysrq(rq);
+ fiq_debugger_end_syslog_dump(state);
+}
+
+#ifdef CONFIG_KGDB
+static void fiq_debugger_do_kgdb(struct fiq_debugger_state *state)
+{
+ if (!fiq_kgdb_enable) {
+ fiq_debugger_printf(&state->output, "kgdb through fiq debugger not enabled\n");
+ return;
+ }
+
+ fiq_debugger_printf(&state->output, "enabling console and triggering kgdb\n");
+ state->console_enable = true;
+ handle_sysrq('g');
+}
+#endif
+
+static void fiq_debugger_schedule_work(struct fiq_debugger_state *state,
+ char *cmd)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&state->work_lock, flags);
+ if (state->work_cmd[0] != '\0') {
+ fiq_debugger_printf(&state->output, "work command processor busy\n");
+ spin_unlock_irqrestore(&state->work_lock, flags);
+ return;
+ }
+
+ strlcpy(state->work_cmd, cmd, sizeof(state->work_cmd));
+ spin_unlock_irqrestore(&state->work_lock, flags);
+
+ schedule_work(&state->work);
+}
+
+static void fiq_debugger_work(struct work_struct *work)
+{
+ struct fiq_debugger_state *state;
+ char work_cmd[DEBUG_MAX];
+ char *cmd;
+ unsigned long flags;
+
+ state = container_of(work, struct fiq_debugger_state, work);
+
+ spin_lock_irqsave(&state->work_lock, flags);
+
+ strlcpy(work_cmd, state->work_cmd, sizeof(work_cmd));
+ state->work_cmd[0] = '\0';
+
+ spin_unlock_irqrestore(&state->work_lock, flags);
+
+ cmd = work_cmd;
+ if (!strncmp(cmd, "reboot", 6)) {
+ cmd += 6;
+ while (*cmd == ' ')
+ cmd++;
+ if (cmd != '\0')
+ kernel_restart(cmd);
+ else
+ kernel_restart(NULL);
+ } else {
+ fiq_debugger_printf(&state->output, "unknown work command '%s'\n",
+ work_cmd);
+ }
+}
+
+/* This function CANNOT be called in FIQ context */
+static void fiq_debugger_irq_exec(struct fiq_debugger_state *state, char *cmd)
+{
+ if (!strcmp(cmd, "ps"))
+ fiq_debugger_do_ps(state);
+ if (!strcmp(cmd, "sysrq"))
+ fiq_debugger_do_sysrq(state, 'h');
+ if (!strncmp(cmd, "sysrq ", 6))
+ fiq_debugger_do_sysrq(state, cmd[6]);
+#ifdef CONFIG_KGDB
+ if (!strcmp(cmd, "kgdb"))
+ fiq_debugger_do_kgdb(state);
+#endif
+ if (!strncmp(cmd, "reboot", 6))
+ fiq_debugger_schedule_work(state, cmd);
+}
+
+static void fiq_debugger_help(struct fiq_debugger_state *state)
+{
+ fiq_debugger_printf(&state->output,
+ "FIQ Debugger commands:\n"
+ " pc PC status\n"
+ " regs Register dump\n"
+ " allregs Extended Register dump\n"
+ " bt Stack trace\n"
+ " reboot [<c>] Reboot with command <c>\n"
+ " reset [<c>] Hard reset with command <c>\n"
+ " irqs Interupt status\n"
+ " kmsg Kernel log\n"
+ " version Kernel version\n");
+ fiq_debugger_printf(&state->output,
+ " sleep Allow sleep while in FIQ\n"
+ " nosleep Disable sleep while in FIQ\n"
+ " console Switch terminal to console\n"
+ " cpu Current CPU\n"
+ " cpu <number> Switch to CPU<number>\n");
+ fiq_debugger_printf(&state->output,
+ " ps Process list\n"
+ " sysrq sysrq options\n"
+ " sysrq <param> Execute sysrq with <param>\n");
+#ifdef CONFIG_KGDB
+ fiq_debugger_printf(&state->output,
+ " kgdb Enter kernel debugger\n");
+#endif
+}
+
+static void fiq_debugger_take_affinity(void *info)
+{
+ struct fiq_debugger_state *state = info;
+ struct cpumask cpumask;
+
+ cpumask_clear(&cpumask);
+ cpumask_set_cpu(get_cpu(), &cpumask);
+
+ irq_set_affinity(state->uart_irq, &cpumask);
+}
+
+static void fiq_debugger_switch_cpu(struct fiq_debugger_state *state, int cpu)
+{
+ if (!fiq_debugger_have_fiq(state))
+ smp_call_function_single(cpu, fiq_debugger_take_affinity, state,
+ false);
+ state->current_cpu = cpu;
+}
+
+static bool fiq_debugger_fiq_exec(struct fiq_debugger_state *state,
+ const char *cmd, const struct pt_regs *regs,
+ void *svc_sp)
+{
+ bool signal_helper = false;
+
+ if (!strcmp(cmd, "help") || !strcmp(cmd, "?")) {
+ fiq_debugger_help(state);
+ } else if (!strcmp(cmd, "pc")) {
+ fiq_debugger_dump_pc(&state->output, regs);
+ } else if (!strcmp(cmd, "regs")) {
+ fiq_debugger_dump_regs(&state->output, regs);
+ } else if (!strcmp(cmd, "allregs")) {
+ fiq_debugger_dump_allregs(&state->output, regs);
+ } else if (!strcmp(cmd, "bt")) {
+ fiq_debugger_dump_stacktrace(&state->output, regs, 100, svc_sp);
+ } else if (!strncmp(cmd, "reset", 5)) {
+ cmd += 5;
+ while (*cmd == ' ')
+ cmd++;
+ if (*cmd) {
+ char tmp_cmd[32];
+ strlcpy(tmp_cmd, cmd, sizeof(tmp_cmd));
+ machine_restart(tmp_cmd);
+ } else {
+ machine_restart(NULL);
+ }
+ } else if (!strcmp(cmd, "irqs")) {
+ fiq_debugger_dump_irqs(state);
+ } else if (!strcmp(cmd, "kmsg")) {
+ fiq_debugger_dump_kernel_log(state);
+ } else if (!strcmp(cmd, "version")) {
+ fiq_debugger_printf(&state->output, "%s\n", linux_banner);
+ } else if (!strcmp(cmd, "sleep")) {
+ state->no_sleep = false;
+ fiq_debugger_printf(&state->output, "enabling sleep\n");
+ } else if (!strcmp(cmd, "nosleep")) {
+ state->no_sleep = true;
+ fiq_debugger_printf(&state->output, "disabling sleep\n");
+ } else if (!strcmp(cmd, "console")) {
+ fiq_debugger_printf(&state->output, "console mode\n");
+ fiq_debugger_uart_flush(state);
+ state->console_enable = true;
+ } else if (!strcmp(cmd, "cpu")) {
+ fiq_debugger_printf(&state->output, "cpu %d\n", state->current_cpu);
+ } else if (!strncmp(cmd, "cpu ", 4)) {
+ unsigned long cpu = 0;
+ if (kstrtoul(cmd + 4, 10, &cpu) == 0)
+ fiq_debugger_switch_cpu(state, cpu);
+ else
+ fiq_debugger_printf(&state->output, "invalid cpu\n");
+ fiq_debugger_printf(&state->output, "cpu %d\n", state->current_cpu);
+ } else {
+ if (state->debug_busy) {
+ fiq_debugger_printf(&state->output,
+ "command processor busy. trying to abort.\n");
+ state->debug_abort = -1;
+ } else {
+ strcpy(state->debug_cmd, cmd);
+ state->debug_busy = 1;
+ }
+
+ return true;
+ }
+ if (!state->console_enable)
+ fiq_debugger_prompt(state);
+
+ return signal_helper;
+}
+
+static void fiq_debugger_sleep_timer_expired(unsigned long data)
+{
+ struct fiq_debugger_state *state = (struct fiq_debugger_state *)data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&state->sleep_timer_lock, flags);
+ if (state->uart_enabled && !state->no_sleep) {
+ if (state->debug_enable && !state->console_enable) {
+ state->debug_enable = false;
+ fiq_debugger_printf_nfiq(state,
+ "suspending fiq debugger\n");
+ }
+ state->ignore_next_wakeup_irq = true;
+ fiq_debugger_uart_disable(state);
+ state->uart_enabled = false;
+ fiq_debugger_enable_wakeup_irq(state);
+ }
+ wake_unlock(&state->debugger_wake_lock);
+ spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
+}
+
+static void fiq_debugger_handle_wakeup(struct fiq_debugger_state *state)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&state->sleep_timer_lock, flags);
+ if (state->wakeup_irq >= 0 && state->ignore_next_wakeup_irq) {
+ state->ignore_next_wakeup_irq = false;
+ } else if (!state->uart_enabled) {
+ wake_lock(&state->debugger_wake_lock);
+ fiq_debugger_uart_enable(state);
+ state->uart_enabled = true;
+ fiq_debugger_disable_wakeup_irq(state);
+ mod_timer(&state->sleep_timer, jiffies + HZ / 2);
+ }
+ spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
+}
+
+static irqreturn_t fiq_debugger_wakeup_irq_handler(int irq, void *dev)
+{
+ struct fiq_debugger_state *state = dev;
+
+ if (!state->no_sleep)
+ fiq_debugger_puts(state, "WAKEUP\n");
+ fiq_debugger_handle_wakeup(state);
+
+ return IRQ_HANDLED;
+}
+
+static
+void fiq_debugger_handle_console_irq_context(struct fiq_debugger_state *state)
+{
+#if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
+ if (state->tty_port.ops) {
+ int i;
+ int count = fiq_debugger_ringbuf_level(state->tty_rbuf);
+ for (i = 0; i < count; i++) {
+ int c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);
+ tty_insert_flip_char(&state->tty_port, c, TTY_NORMAL);
+ if (!fiq_debugger_ringbuf_consume(state->tty_rbuf, 1))
+ pr_warn("fiq tty failed to consume byte\n");
+ }
+ tty_flip_buffer_push(&state->tty_port);
+ }
+#endif
+}
+
+static void fiq_debugger_handle_irq_context(struct fiq_debugger_state *state)
+{
+ if (!state->no_sleep) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&state->sleep_timer_lock, flags);
+ wake_lock(&state->debugger_wake_lock);
+ mod_timer(&state->sleep_timer, jiffies + HZ * 5);
+ spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
+ }
+ fiq_debugger_handle_console_irq_context(state);
+ if (state->debug_busy) {
+ fiq_debugger_irq_exec(state, state->debug_cmd);
+ if (!state->console_enable)
+ fiq_debugger_prompt(state);
+ state->debug_busy = 0;
+ }
+}
+
+static int fiq_debugger_getc(struct fiq_debugger_state *state)
+{
+ return state->pdata->uart_getc(state->pdev);
+}
+
+static bool fiq_debugger_handle_uart_interrupt(struct fiq_debugger_state *state,
+ int this_cpu, const struct pt_regs *regs, void *svc_sp)
+{
+ int c;
+ static int last_c;
+ int count = 0;
+ bool signal_helper = false;
+
+ if (this_cpu != state->current_cpu) {
+ if (state->in_fiq)
+ return false;
+
+ if (atomic_inc_return(&state->unhandled_fiq_count) !=
+ MAX_UNHANDLED_FIQ_COUNT)
+ return false;
+
+ fiq_debugger_printf(&state->output,
+ "fiq_debugger: cpu %d not responding, "
+ "reverting to cpu %d\n", state->current_cpu,
+ this_cpu);
+
+ atomic_set(&state->unhandled_fiq_count, 0);
+ fiq_debugger_switch_cpu(state, this_cpu);
+ return false;
+ }
+
+ state->in_fiq = true;
+
+ while ((c = fiq_debugger_getc(state)) != FIQ_DEBUGGER_NO_CHAR) {
+ count++;
+ if (!state->debug_enable) {
+ if ((c == 13) || (c == 10)) {
+ state->debug_enable = true;
+ state->debug_count = 0;
+ fiq_debugger_prompt(state);
+ }
+ } else if (c == FIQ_DEBUGGER_BREAK) {
+ state->console_enable = false;
+ fiq_debugger_puts(state, "fiq debugger mode\n");
+ state->debug_count = 0;
+ fiq_debugger_prompt(state);
+#ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
+ } else if (state->console_enable && state->tty_rbuf) {
+ fiq_debugger_ringbuf_push(state->tty_rbuf, c);
+ signal_helper = true;
+#endif
+ } else if ((c >= ' ') && (c < 127)) {
+ if (state->debug_count < (DEBUG_MAX - 1)) {
+ state->debug_buf[state->debug_count++] = c;
+ fiq_debugger_putc(state, c);
+ }
+ } else if ((c == 8) || (c == 127)) {
+ if (state->debug_count > 0) {
+ state->debug_count--;
+ fiq_debugger_putc(state, 8);
+ fiq_debugger_putc(state, ' ');
+ fiq_debugger_putc(state, 8);
+ }
+ } else if ((c == 13) || (c == 10)) {
+ if (c == '\r' || (c == '\n' && last_c != '\r')) {
+ fiq_debugger_putc(state, '\r');
+ fiq_debugger_putc(state, '\n');
+ }
+ if (state->debug_count) {
+ state->debug_buf[state->debug_count] = 0;
+ state->debug_count = 0;
+ signal_helper |=
+ fiq_debugger_fiq_exec(state,
+ state->debug_buf,
+ regs, svc_sp);
+ } else {
+ fiq_debugger_prompt(state);
+ }
+ }
+ last_c = c;
+ }
+ if (!state->console_enable)
+ fiq_debugger_uart_flush(state);
+ if (state->pdata->fiq_ack)
+ state->pdata->fiq_ack(state->pdev, state->fiq);
+
+ /* poke sleep timer if necessary */
+ if (state->debug_enable && !state->no_sleep)
+ signal_helper = true;
+
+ atomic_set(&state->unhandled_fiq_count, 0);
+ state->in_fiq = false;
+
+ return signal_helper;
+}
+
+#ifdef CONFIG_FIQ_GLUE
+static void fiq_debugger_fiq(struct fiq_glue_handler *h,
+ const struct pt_regs *regs, void *svc_sp)
+{
+ struct fiq_debugger_state *state =
+ container_of(h, struct fiq_debugger_state, handler);
+ unsigned int this_cpu = THREAD_INFO(svc_sp)->cpu;
+ bool need_irq;
+
+ need_irq = fiq_debugger_handle_uart_interrupt(state, this_cpu, regs,
+ svc_sp);
+ if (need_irq)
+ fiq_debugger_force_irq(state);
+}
+#endif
+
+/*
+ * When not using FIQs, we only use this single interrupt as an entry point.
+ * This just effectively takes over the UART interrupt and does all the work
+ * in this context.
+ */
+static irqreturn_t fiq_debugger_uart_irq(int irq, void *dev)
+{
+ struct fiq_debugger_state *state = dev;
+ bool not_done;
+
+ fiq_debugger_handle_wakeup(state);
+
+ /* handle the debugger irq in regular context */
+ not_done = fiq_debugger_handle_uart_interrupt(state, smp_processor_id(),
+ get_irq_regs(),
+ current_thread_info());
+ if (not_done)
+ fiq_debugger_handle_irq_context(state);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * If FIQs are used, not everything can happen in fiq context.
+ * FIQ handler does what it can and then signals this interrupt to finish the
+ * job in irq context.
+ */
+static irqreturn_t fiq_debugger_signal_irq(int irq, void *dev)
+{
+ struct fiq_debugger_state *state = dev;
+
+ if (state->pdata->force_irq_ack)
+ state->pdata->force_irq_ack(state->pdev, state->signal_irq);
+
+ fiq_debugger_handle_irq_context(state);
+
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_FIQ_GLUE
+static void fiq_debugger_resume(struct fiq_glue_handler *h)
+{
+ struct fiq_debugger_state *state =
+ container_of(h, struct fiq_debugger_state, handler);
+ if (state->pdata->uart_resume)
+ state->pdata->uart_resume(state->pdev);
+}
+#endif
+
+#if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
+struct tty_driver *fiq_debugger_console_device(struct console *co, int *index)
+{
+ *index = co->index;
+ return fiq_tty_driver;
+}
+
+static void fiq_debugger_console_write(struct console *co,
+ const char *s, unsigned int count)
+{
+ struct fiq_debugger_state *state;
+ unsigned long flags;
+
+ state = container_of(co, struct fiq_debugger_state, console);
+
+ if (!state->console_enable && !state->syslog_dumping)
+ return;
+
+ fiq_debugger_uart_enable(state);
+ spin_lock_irqsave(&state->console_lock, flags);
+ while (count--) {
+ if (*s == '\n')
+ fiq_debugger_putc(state, '\r');
+ fiq_debugger_putc(state, *s++);
+ }
+ fiq_debugger_uart_flush(state);
+ spin_unlock_irqrestore(&state->console_lock, flags);
+ fiq_debugger_uart_disable(state);
+}
+
+static struct console fiq_debugger_console = {
+ .name = "ttyFIQ",
+ .device = fiq_debugger_console_device,
+ .write = fiq_debugger_console_write,
+ .flags = CON_PRINTBUFFER | CON_ANYTIME | CON_ENABLED,
+};
+
+int fiq_tty_open(struct tty_struct *tty, struct file *filp)
+{
+ int line = tty->index;
+ struct fiq_debugger_state **states = tty->driver->driver_state;
+ struct fiq_debugger_state *state = states[line];
+
+ return tty_port_open(&state->tty_port, tty, filp);
+}
+
+void fiq_tty_close(struct tty_struct *tty, struct file *filp)
+{
+ tty_port_close(tty->port, tty, filp);
+}
+
+int fiq_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
+{
+ int i;
+ int line = tty->index;
+ struct fiq_debugger_state **states = tty->driver->driver_state;
+ struct fiq_debugger_state *state = states[line];
+
+ if (!state->console_enable)
+ return count;
+
+ fiq_debugger_uart_enable(state);
+ spin_lock_irq(&state->console_lock);
+ for (i = 0; i < count; i++)
+ fiq_debugger_putc(state, *buf++);
+ spin_unlock_irq(&state->console_lock);
+ fiq_debugger_uart_disable(state);
+
+ return count;
+}
+
+int fiq_tty_write_room(struct tty_struct *tty)
+{
+ return 16;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int fiq_tty_poll_init(struct tty_driver *driver, int line, char *options)
+{
+ return 0;
+}
+
+static int fiq_tty_poll_get_char(struct tty_driver *driver, int line)
+{
+ struct fiq_debugger_state **states = driver->driver_state;
+ struct fiq_debugger_state *state = states[line];
+ int c = NO_POLL_CHAR;
+
+ fiq_debugger_uart_enable(state);
+ if (fiq_debugger_have_fiq(state)) {
+ int count = fiq_debugger_ringbuf_level(state->tty_rbuf);
+ if (count > 0) {
+ c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);
+ fiq_debugger_ringbuf_consume(state->tty_rbuf, 1);
+ }
+ } else {
+ c = fiq_debugger_getc(state);
+ if (c == FIQ_DEBUGGER_NO_CHAR)
+ c = NO_POLL_CHAR;
+ }
+ fiq_debugger_uart_disable(state);
+
+ return c;
+}
+
+static void fiq_tty_poll_put_char(struct tty_driver *driver, int line, char ch)
+{
+ struct fiq_debugger_state **states = driver->driver_state;
+ struct fiq_debugger_state *state = states[line];
+ fiq_debugger_uart_enable(state);
+ fiq_debugger_putc(state, ch);
+ fiq_debugger_uart_disable(state);
+}
+#endif
+
+static const struct tty_port_operations fiq_tty_port_ops;
+
+static const struct tty_operations fiq_tty_driver_ops = {
+ .write = fiq_tty_write,
+ .write_room = fiq_tty_write_room,
+ .open = fiq_tty_open,
+ .close = fiq_tty_close,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_init = fiq_tty_poll_init,
+ .poll_get_char = fiq_tty_poll_get_char,
+ .poll_put_char = fiq_tty_poll_put_char,
+#endif
+};
+
+static int fiq_debugger_tty_init(void)
+{
+ int ret;
+ struct fiq_debugger_state **states = NULL;
+
+ states = kzalloc(sizeof(*states) * MAX_FIQ_DEBUGGER_PORTS, GFP_KERNEL);
+ if (!states) {
+ pr_err("Failed to allocate fiq debugger state structres\n");
+ return -ENOMEM;
+ }
+
+ fiq_tty_driver = alloc_tty_driver(MAX_FIQ_DEBUGGER_PORTS);
+ if (!fiq_tty_driver) {
+ pr_err("Failed to allocate fiq debugger tty\n");
+ ret = -ENOMEM;
+ goto err_free_state;
+ }
+
+ fiq_tty_driver->owner = THIS_MODULE;
+ fiq_tty_driver->driver_name = "fiq-debugger";
+ fiq_tty_driver->name = "ttyFIQ";
+ fiq_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
+ fiq_tty_driver->subtype = SERIAL_TYPE_NORMAL;
+ fiq_tty_driver->init_termios = tty_std_termios;
+ fiq_tty_driver->flags = TTY_DRIVER_REAL_RAW |
+ TTY_DRIVER_DYNAMIC_DEV;
+ fiq_tty_driver->driver_state = states;
+
+ fiq_tty_driver->init_termios.c_cflag =
+ B115200 | CS8 | CREAD | HUPCL | CLOCAL;
+ fiq_tty_driver->init_termios.c_ispeed = 115200;
+ fiq_tty_driver->init_termios.c_ospeed = 115200;
+
+ tty_set_operations(fiq_tty_driver, &fiq_tty_driver_ops);
+
+ ret = tty_register_driver(fiq_tty_driver);
+ if (ret) {
+ pr_err("Failed to register fiq tty: %d\n", ret);
+ goto err_free_tty;
+ }
+
+ pr_info("Registered FIQ tty driver\n");
+ return 0;
+
+err_free_tty:
+ put_tty_driver(fiq_tty_driver);
+ fiq_tty_driver = NULL;
+err_free_state:
+ kfree(states);
+ return ret;
+}
+
+static int fiq_debugger_tty_init_one(struct fiq_debugger_state *state)
+{
+ int ret;
+ struct device *tty_dev;
+ struct fiq_debugger_state **states = fiq_tty_driver->driver_state;
+
+ states[state->pdev->id] = state;
+
+ state->tty_rbuf = fiq_debugger_ringbuf_alloc(1024);
+ if (!state->tty_rbuf) {
+ pr_err("Failed to allocate fiq debugger ringbuf\n");
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ tty_port_init(&state->tty_port);
+ state->tty_port.ops = &fiq_tty_port_ops;
+
+ tty_dev = tty_port_register_device(&state->tty_port, fiq_tty_driver,
+ state->pdev->id, &state->pdev->dev);
+ if (IS_ERR(tty_dev)) {
+ pr_err("Failed to register fiq debugger tty device\n");
+ ret = PTR_ERR(tty_dev);
+ goto err;
+ }
+
+ device_set_wakeup_capable(tty_dev, 1);
+
+ pr_info("Registered fiq debugger ttyFIQ%d\n", state->pdev->id);
+
+ return 0;
+
+err:
+ fiq_debugger_ringbuf_free(state->tty_rbuf);
+ state->tty_rbuf = NULL;
+ return ret;
+}
+#endif
+
+static int fiq_debugger_dev_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct fiq_debugger_state *state = platform_get_drvdata(pdev);
+
+ if (state->pdata->uart_dev_suspend)
+ return state->pdata->uart_dev_suspend(pdev);
+ return 0;
+}
+
+static int fiq_debugger_dev_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct fiq_debugger_state *state = platform_get_drvdata(pdev);
+
+ if (state->pdata->uart_dev_resume)
+ return state->pdata->uart_dev_resume(pdev);
+ return 0;
+}
+
+static int fiq_debugger_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct fiq_debugger_pdata *pdata = dev_get_platdata(&pdev->dev);
+ struct fiq_debugger_state *state;
+ int fiq;
+ int uart_irq;
+
+ if (pdev->id >= MAX_FIQ_DEBUGGER_PORTS)
+ return -EINVAL;
+
+ if (!pdata->uart_getc || !pdata->uart_putc)
+ return -EINVAL;
+ if ((pdata->uart_enable && !pdata->uart_disable) ||
+ (!pdata->uart_enable && pdata->uart_disable))
+ return -EINVAL;
+
+ fiq = platform_get_irq_byname(pdev, "fiq");
+ uart_irq = platform_get_irq_byname(pdev, "uart_irq");
+
+ /* uart_irq mode and fiq mode are mutually exclusive, but one of them
+ * is required */
+ if ((uart_irq < 0 && fiq < 0) || (uart_irq >= 0 && fiq >= 0))
+ return -EINVAL;
+ if (fiq >= 0 && !pdata->fiq_enable)
+ return -EINVAL;
+
+ state = kzalloc(sizeof(*state), GFP_KERNEL);
+ state->output.printf = fiq_debugger_printf;
+ setup_timer(&state->sleep_timer, fiq_debugger_sleep_timer_expired,
+ (unsigned long)state);
+ state->pdata = pdata;
+ state->pdev = pdev;
+ state->no_sleep = initial_no_sleep;
+ state->debug_enable = initial_debug_enable;
+ state->console_enable = initial_console_enable;
+
+ state->fiq = fiq;
+ state->uart_irq = uart_irq;
+ state->signal_irq = platform_get_irq_byname(pdev, "signal");
+ state->wakeup_irq = platform_get_irq_byname(pdev, "wakeup");
+
+ INIT_WORK(&state->work, fiq_debugger_work);
+ spin_lock_init(&state->work_lock);
+
+ platform_set_drvdata(pdev, state);
+
+ spin_lock_init(&state->sleep_timer_lock);
+
+ if (state->wakeup_irq < 0 && fiq_debugger_have_fiq(state))
+ state->no_sleep = true;
+ state->ignore_next_wakeup_irq = !state->no_sleep;
+
+ wake_lock_init(&state->debugger_wake_lock,
+ WAKE_LOCK_SUSPEND, "serial-debug");
+
+ state->clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(state->clk))
+ state->clk = NULL;
+
+ /* do not call pdata->uart_enable here since uart_init may still
+ * need to do some initialization before uart_enable can work.
+ * So, only try to manage the clock during init.
+ */
+ if (state->clk)
+ clk_enable(state->clk);
+
+ if (pdata->uart_init) {
+ ret = pdata->uart_init(pdev);
+ if (ret)
+ goto err_uart_init;
+ }
+
+ fiq_debugger_printf_nfiq(state,
+ "<hit enter %sto activate fiq debugger>\n",
+ state->no_sleep ? "" : "twice ");
+
+#ifdef CONFIG_FIQ_GLUE
+ if (fiq_debugger_have_fiq(state)) {
+ state->handler.fiq = fiq_debugger_fiq;
+ state->handler.resume = fiq_debugger_resume;
+ ret = fiq_glue_register_handler(&state->handler);
+ if (ret) {
+ pr_err("%s: could not install fiq handler\n", __func__);
+ goto err_register_irq;
+ }
+
+ pdata->fiq_enable(pdev, state->fiq, 1);
+ } else
+#endif
+ {
+ ret = request_irq(state->uart_irq, fiq_debugger_uart_irq,
+ IRQF_NO_SUSPEND, "debug", state);
+ if (ret) {
+ pr_err("%s: could not install irq handler\n", __func__);
+ goto err_register_irq;
+ }
+
+ /* for irq-only mode, we want this irq to wake us up, if it
+ * can.
+ */
+ enable_irq_wake(state->uart_irq);
+ }
+
+ if (state->clk)
+ clk_disable(state->clk);
+
+ if (state->signal_irq >= 0) {
+ ret = request_irq(state->signal_irq, fiq_debugger_signal_irq,
+ IRQF_TRIGGER_RISING, "debug-signal", state);
+ if (ret)
+ pr_err("serial_debugger: could not install signal_irq");
+ }
+
+ if (state->wakeup_irq >= 0) {
+ ret = request_irq(state->wakeup_irq,
+ fiq_debugger_wakeup_irq_handler,
+ IRQF_TRIGGER_FALLING,
+ "debug-wakeup", state);
+ if (ret) {
+ pr_err("serial_debugger: "
+ "could not install wakeup irq\n");
+ state->wakeup_irq = -1;
+ } else {
+ ret = enable_irq_wake(state->wakeup_irq);
+ if (ret) {
+ pr_err("serial_debugger: "
+ "could not enable wakeup\n");
+ state->wakeup_irq_no_set_wake = true;
+ }
+ }
+ }
+ if (state->no_sleep)
+ fiq_debugger_handle_wakeup(state);
+
+#if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
+ spin_lock_init(&state->console_lock);
+ state->console = fiq_debugger_console;
+ state->console.index = pdev->id;
+ if (!console_set_on_cmdline)
+ add_preferred_console(state->console.name,
+ state->console.index, NULL);
+ register_console(&state->console);
+ fiq_debugger_tty_init_one(state);
+#endif
+ return 0;
+
+err_register_irq:
+ if (pdata->uart_free)
+ pdata->uart_free(pdev);
+err_uart_init:
+ if (state->clk)
+ clk_disable(state->clk);
+ if (state->clk)
+ clk_put(state->clk);
+ wake_lock_destroy(&state->debugger_wake_lock);
+ platform_set_drvdata(pdev, NULL);
+ kfree(state);
+ return ret;
+}
+
+static const struct dev_pm_ops fiq_debugger_dev_pm_ops = {
+ .suspend = fiq_debugger_dev_suspend,
+ .resume = fiq_debugger_dev_resume,
+};
+
+static struct platform_driver fiq_debugger_driver = {
+ .probe = fiq_debugger_probe,
+ .driver = {
+ .name = "fiq_debugger",
+ .pm = &fiq_debugger_dev_pm_ops,
+ },
+};
+
+#if defined(CONFIG_FIQ_DEBUGGER_UART_OVERLAY)
+int fiq_debugger_uart_overlay(void)
+{
+ struct device_node *onp = of_find_node_by_path("/uart_overlay@0");
+ int ret;
+
+ if (!onp) {
+ pr_err("serial_debugger: uart overlay not found\n");
+ return -ENODEV;
+ }
+
+ ret = of_overlay_create(onp);
+ if (ret < 0) {
+ pr_err("serial_debugger: fail to create overlay: %d\n", ret);
+ of_node_put(onp);
+ return ret;
+ }
+
+ pr_info("serial_debugger: uart overlay applied\n");
+ return 0;
+}
+#endif
+
+static int __init fiq_debugger_init(void)
+{
+ if (fiq_debugger_disable) {
+ pr_err("serial_debugger: disabled\n");
+ return -ENODEV;
+ }
+#if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
+ fiq_debugger_tty_init();
+#endif
+#if defined(CONFIG_FIQ_DEBUGGER_UART_OVERLAY)
+ fiq_debugger_uart_overlay();
+#endif
+ return platform_driver_register(&fiq_debugger_driver);
+}
+
+postcore_initcall(fiq_debugger_init);
diff --git a/drivers/staging/android/fiq_debugger/fiq_debugger.h b/drivers/staging/android/fiq_debugger/fiq_debugger.h
new file mode 100644
index 000000000000..c9ec4f8db086
--- /dev/null
+++ b/drivers/staging/android/fiq_debugger/fiq_debugger.h
@@ -0,0 +1,64 @@
+/*
+ * drivers/staging/android/fiq_debugger/fiq_debugger.h
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Author: Colin Cross <ccross@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _ARCH_ARM_MACH_TEGRA_FIQ_DEBUGGER_H_
+#define _ARCH_ARM_MACH_TEGRA_FIQ_DEBUGGER_H_
+
+#include <linux/serial_core.h>
+
+#define FIQ_DEBUGGER_NO_CHAR NO_POLL_CHAR
+#define FIQ_DEBUGGER_BREAK 0x00ff0100
+
+#define FIQ_DEBUGGER_FIQ_IRQ_NAME "fiq"
+#define FIQ_DEBUGGER_SIGNAL_IRQ_NAME "signal"
+#define FIQ_DEBUGGER_WAKEUP_IRQ_NAME "wakeup"
+
+/**
+ * struct fiq_debugger_pdata - fiq debugger platform data
+ * @uart_resume: used to restore uart state right before enabling
+ * the fiq.
+ * @uart_enable: Do the work necessary to communicate with the uart
+ * hw (enable clocks, etc.). This must be ref-counted.
+ * @uart_disable: Do the work necessary to disable the uart hw
+ * (disable clocks, etc.). This must be ref-counted.
+ * @uart_dev_suspend: called during PM suspend, generally not needed
+ * for real fiq mode debugger.
+ * @uart_dev_resume: called during PM resume, generally not needed
+ * for real fiq mode debugger.
+ */
+struct fiq_debugger_pdata {
+ int (*uart_init)(struct platform_device *pdev);
+ void (*uart_free)(struct platform_device *pdev);
+ int (*uart_resume)(struct platform_device *pdev);
+ int (*uart_getc)(struct platform_device *pdev);
+ void (*uart_putc)(struct platform_device *pdev, unsigned int c);
+ void (*uart_flush)(struct platform_device *pdev);
+ void (*uart_enable)(struct platform_device *pdev);
+ void (*uart_disable)(struct platform_device *pdev);
+
+ int (*uart_dev_suspend)(struct platform_device *pdev);
+ int (*uart_dev_resume)(struct platform_device *pdev);
+
+ void (*fiq_enable)(struct platform_device *pdev, unsigned int fiq,
+ bool enable);
+ void (*fiq_ack)(struct platform_device *pdev, unsigned int fiq);
+
+ void (*force_irq)(struct platform_device *pdev, unsigned int irq);
+ void (*force_irq_ack)(struct platform_device *pdev, unsigned int irq);
+};
+
+#endif
diff --git a/drivers/staging/android/fiq_debugger/fiq_debugger_arm.c b/drivers/staging/android/fiq_debugger/fiq_debugger_arm.c
new file mode 100644
index 000000000000..8b3e0137be1a
--- /dev/null
+++ b/drivers/staging/android/fiq_debugger/fiq_debugger_arm.c
@@ -0,0 +1,240 @@
+/*
+ * Copyright (C) 2014 Google, Inc.
+ * Author: Colin Cross <ccross@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/ptrace.h>
+#include <linux/uaccess.h>
+
+#include <asm/stacktrace.h>
+
+#include "fiq_debugger_priv.h"
+
+static char *mode_name(unsigned cpsr)
+{
+ switch (cpsr & MODE_MASK) {
+ case USR_MODE: return "USR";
+ case FIQ_MODE: return "FIQ";
+ case IRQ_MODE: return "IRQ";
+ case SVC_MODE: return "SVC";
+ case ABT_MODE: return "ABT";
+ case UND_MODE: return "UND";
+ case SYSTEM_MODE: return "SYS";
+ default: return "???";
+ }
+}
+
+void fiq_debugger_dump_pc(struct fiq_debugger_output *output,
+ const struct pt_regs *regs)
+{
+ output->printf(output, " pc %08x cpsr %08x mode %s\n",
+ regs->ARM_pc, regs->ARM_cpsr, mode_name(regs->ARM_cpsr));
+}
+
+void fiq_debugger_dump_regs(struct fiq_debugger_output *output,
+ const struct pt_regs *regs)
+{
+ output->printf(output,
+ " r0 %08x r1 %08x r2 %08x r3 %08x\n",
+ regs->ARM_r0, regs->ARM_r1, regs->ARM_r2, regs->ARM_r3);
+ output->printf(output,
+ " r4 %08x r5 %08x r6 %08x r7 %08x\n",
+ regs->ARM_r4, regs->ARM_r5, regs->ARM_r6, regs->ARM_r7);
+ output->printf(output,
+ " r8 %08x r9 %08x r10 %08x r11 %08x mode %s\n",
+ regs->ARM_r8, regs->ARM_r9, regs->ARM_r10, regs->ARM_fp,
+ mode_name(regs->ARM_cpsr));
+ output->printf(output,
+ " ip %08x sp %08x lr %08x pc %08x cpsr %08x\n",
+ regs->ARM_ip, regs->ARM_sp, regs->ARM_lr, regs->ARM_pc,
+ regs->ARM_cpsr);
+}
+
+struct mode_regs {
+ unsigned long sp_svc;
+ unsigned long lr_svc;
+ unsigned long spsr_svc;
+
+ unsigned long sp_abt;
+ unsigned long lr_abt;
+ unsigned long spsr_abt;
+
+ unsigned long sp_und;
+ unsigned long lr_und;
+ unsigned long spsr_und;
+
+ unsigned long sp_irq;
+ unsigned long lr_irq;
+ unsigned long spsr_irq;
+
+ unsigned long r8_fiq;
+ unsigned long r9_fiq;
+ unsigned long r10_fiq;
+ unsigned long r11_fiq;
+ unsigned long r12_fiq;
+ unsigned long sp_fiq;
+ unsigned long lr_fiq;
+ unsigned long spsr_fiq;
+};
+
+static void __naked get_mode_regs(struct mode_regs *regs)
+{
+ asm volatile (
+ "mrs r1, cpsr\n"
+ "msr cpsr_c, #0xd3 @(SVC_MODE | PSR_I_BIT | PSR_F_BIT)\n"
+ "stmia r0!, {r13 - r14}\n"
+ "mrs r2, spsr\n"
+ "msr cpsr_c, #0xd7 @(ABT_MODE | PSR_I_BIT | PSR_F_BIT)\n"
+ "stmia r0!, {r2, r13 - r14}\n"
+ "mrs r2, spsr\n"
+ "msr cpsr_c, #0xdb @(UND_MODE | PSR_I_BIT | PSR_F_BIT)\n"
+ "stmia r0!, {r2, r13 - r14}\n"
+ "mrs r2, spsr\n"
+ "msr cpsr_c, #0xd2 @(IRQ_MODE | PSR_I_BIT | PSR_F_BIT)\n"
+ "stmia r0!, {r2, r13 - r14}\n"
+ "mrs r2, spsr\n"
+ "msr cpsr_c, #0xd1 @(FIQ_MODE | PSR_I_BIT | PSR_F_BIT)\n"
+ "stmia r0!, {r2, r8 - r14}\n"
+ "mrs r2, spsr\n"
+ "stmia r0!, {r2}\n"
+ "msr cpsr_c, r1\n"
+ "bx lr\n");
+}
+
+
+void fiq_debugger_dump_allregs(struct fiq_debugger_output *output,
+ const struct pt_regs *regs)
+{
+ struct mode_regs mode_regs;
+ unsigned long mode = regs->ARM_cpsr & MODE_MASK;
+
+ fiq_debugger_dump_regs(output, regs);
+ get_mode_regs(&mode_regs);
+
+ output->printf(output,
+ "%csvc: sp %08x lr %08x spsr %08x\n",
+ mode == SVC_MODE ? '*' : ' ',
+ mode_regs.sp_svc, mode_regs.lr_svc, mode_regs.spsr_svc);
+ output->printf(output,
+ "%cabt: sp %08x lr %08x spsr %08x\n",
+ mode == ABT_MODE ? '*' : ' ',
+ mode_regs.sp_abt, mode_regs.lr_abt, mode_regs.spsr_abt);
+ output->printf(output,
+ "%cund: sp %08x lr %08x spsr %08x\n",
+ mode == UND_MODE ? '*' : ' ',
+ mode_regs.sp_und, mode_regs.lr_und, mode_regs.spsr_und);
+ output->printf(output,
+ "%cirq: sp %08x lr %08x spsr %08x\n",
+ mode == IRQ_MODE ? '*' : ' ',
+ mode_regs.sp_irq, mode_regs.lr_irq, mode_regs.spsr_irq);
+ output->printf(output,
+ "%cfiq: r8 %08x r9 %08x r10 %08x r11 %08x r12 %08x\n",
+ mode == FIQ_MODE ? '*' : ' ',
+ mode_regs.r8_fiq, mode_regs.r9_fiq, mode_regs.r10_fiq,
+ mode_regs.r11_fiq, mode_regs.r12_fiq);
+ output->printf(output,
+ " fiq: sp %08x lr %08x spsr %08x\n",
+ mode_regs.sp_fiq, mode_regs.lr_fiq, mode_regs.spsr_fiq);
+}
+
+struct stacktrace_state {
+ struct fiq_debugger_output *output;
+ unsigned int depth;
+};
+
+static int report_trace(struct stackframe *frame, void *d)
+{
+ struct stacktrace_state *sts = d;
+
+ if (sts->depth) {
+ sts->output->printf(sts->output,
+ " pc: %p (%pF), lr %p (%pF), sp %p, fp %p\n",
+ frame->pc, frame->pc, frame->lr, frame->lr,
+ frame->sp, frame->fp);
+ sts->depth--;
+ return 0;
+ }
+ sts->output->printf(sts->output, " ...\n");
+
+ return sts->depth == 0;
+}
+
+struct frame_tail {
+ struct frame_tail *fp;
+ unsigned long sp;
+ unsigned long lr;
+} __attribute__((packed));
+
+static struct frame_tail *user_backtrace(struct fiq_debugger_output *output,
+ struct frame_tail *tail)
+{
+ struct frame_tail buftail[2];
+
+ /* Also check accessibility of one struct frame_tail beyond */
+ if (!access_ok(VERIFY_READ, tail, sizeof(buftail))) {
+ output->printf(output, " invalid frame pointer %p\n",
+ tail);
+ return NULL;
+ }
+ if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail))) {
+ output->printf(output,
+ " failed to copy frame pointer %p\n", tail);
+ return NULL;
+ }
+
+ output->printf(output, " %p\n", buftail[0].lr);
+
+ /* frame pointers should strictly progress back up the stack
+ * (towards higher addresses) */
+ if (tail >= buftail[0].fp)
+ return NULL;
+
+ return buftail[0].fp-1;
+}
+
+void fiq_debugger_dump_stacktrace(struct fiq_debugger_output *output,
+ const struct pt_regs *regs, unsigned int depth, void *ssp)
+{
+ struct frame_tail *tail;
+ struct thread_info *real_thread_info = THREAD_INFO(ssp);
+ struct stacktrace_state sts;
+
+ sts.depth = depth;
+ sts.output = output;
+ *current_thread_info() = *real_thread_info;
+
+ if (!current)
+ output->printf(output, "current NULL\n");
+ else
+ output->printf(output, "pid: %d comm: %s\n",
+ current->pid, current->comm);
+ fiq_debugger_dump_regs(output, regs);
+
+ if (!user_mode(regs)) {
+ struct stackframe frame;
+ frame.fp = regs->ARM_fp;
+ frame.sp = regs->ARM_sp;
+ frame.lr = regs->ARM_lr;
+ frame.pc = regs->ARM_pc;
+ output->printf(output,
+ " pc: %p (%pF), lr %p (%pF), sp %p, fp %p\n",
+ regs->ARM_pc, regs->ARM_pc, regs->ARM_lr, regs->ARM_lr,
+ regs->ARM_sp, regs->ARM_fp);
+ walk_stackframe(&frame, report_trace, &sts);
+ return;
+ }
+
+ tail = ((struct frame_tail *) regs->ARM_fp) - 1;
+ while (depth-- && tail && !((unsigned long) tail & 3))
+ tail = user_backtrace(output, tail);
+}
diff --git a/drivers/staging/android/fiq_debugger/fiq_debugger_arm64.c b/drivers/staging/android/fiq_debugger/fiq_debugger_arm64.c
new file mode 100644
index 000000000000..97246bcbcd62
--- /dev/null
+++ b/drivers/staging/android/fiq_debugger/fiq_debugger_arm64.c
@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2014 Google, Inc.
+ * Author: Colin Cross <ccross@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/ptrace.h>
+#include <asm/stacktrace.h>
+
+#include "fiq_debugger_priv.h"
+
+static char *mode_name(const struct pt_regs *regs)
+{
+ if (compat_user_mode(regs)) {
+ return "USR";
+ } else {
+ switch (processor_mode(regs)) {
+ case PSR_MODE_EL0t: return "EL0t";
+ case PSR_MODE_EL1t: return "EL1t";
+ case PSR_MODE_EL1h: return "EL1h";
+ case PSR_MODE_EL2t: return "EL2t";
+ case PSR_MODE_EL2h: return "EL2h";
+ default: return "???";
+ }
+ }
+}
+
+void fiq_debugger_dump_pc(struct fiq_debugger_output *output,
+ const struct pt_regs *regs)
+{
+ output->printf(output, " pc %016lx cpsr %08lx mode %s\n",
+ regs->pc, regs->pstate, mode_name(regs));
+}
+
+void fiq_debugger_dump_regs_aarch32(struct fiq_debugger_output *output,
+ const struct pt_regs *regs)
+{
+ output->printf(output, " r0 %08x r1 %08x r2 %08x r3 %08x\n",
+ regs->compat_usr(0), regs->compat_usr(1),
+ regs->compat_usr(2), regs->compat_usr(3));
+ output->printf(output, " r4 %08x r5 %08x r6 %08x r7 %08x\n",
+ regs->compat_usr(4), regs->compat_usr(5),
+ regs->compat_usr(6), regs->compat_usr(7));
+ output->printf(output, " r8 %08x r9 %08x r10 %08x r11 %08x\n",
+ regs->compat_usr(8), regs->compat_usr(9),
+ regs->compat_usr(10), regs->compat_usr(11));
+ output->printf(output, " ip %08x sp %08x lr %08x pc %08x\n",
+ regs->compat_usr(12), regs->compat_sp,
+ regs->compat_lr, regs->pc);
+ output->printf(output, " cpsr %08x (%s)\n",
+ regs->pstate, mode_name(regs));
+}
+
+void fiq_debugger_dump_regs_aarch64(struct fiq_debugger_output *output,
+ const struct pt_regs *regs)
+{
+
+ output->printf(output, " x0 %016lx x1 %016lx\n",
+ regs->regs[0], regs->regs[1]);
+ output->printf(output, " x2 %016lx x3 %016lx\n",
+ regs->regs[2], regs->regs[3]);
+ output->printf(output, " x4 %016lx x5 %016lx\n",
+ regs->regs[4], regs->regs[5]);
+ output->printf(output, " x6 %016lx x7 %016lx\n",
+ regs->regs[6], regs->regs[7]);
+ output->printf(output, " x8 %016lx x9 %016lx\n",
+ regs->regs[8], regs->regs[9]);
+ output->printf(output, " x10 %016lx x11 %016lx\n",
+ regs->regs[10], regs->regs[11]);
+ output->printf(output, " x12 %016lx x13 %016lx\n",
+ regs->regs[12], regs->regs[13]);
+ output->printf(output, " x14 %016lx x15 %016lx\n",
+ regs->regs[14], regs->regs[15]);
+ output->printf(output, " x16 %016lx x17 %016lx\n",
+ regs->regs[16], regs->regs[17]);
+ output->printf(output, " x18 %016lx x19 %016lx\n",
+ regs->regs[18], regs->regs[19]);
+ output->printf(output, " x20 %016lx x21 %016lx\n",
+ regs->regs[20], regs->regs[21]);
+ output->printf(output, " x22 %016lx x23 %016lx\n",
+ regs->regs[22], regs->regs[23]);
+ output->printf(output, " x24 %016lx x25 %016lx\n",
+ regs->regs[24], regs->regs[25]);
+ output->printf(output, " x26 %016lx x27 %016lx\n",
+ regs->regs[26], regs->regs[27]);
+ output->printf(output, " x28 %016lx x29 %016lx\n",
+ regs->regs[28], regs->regs[29]);
+ output->printf(output, " x30 %016lx sp %016lx\n",
+ regs->regs[30], regs->sp);
+ output->printf(output, " pc %016lx cpsr %08x (%s)\n",
+ regs->pc, regs->pstate, mode_name(regs));
+}
+
+void fiq_debugger_dump_regs(struct fiq_debugger_output *output,
+ const struct pt_regs *regs)
+{
+ if (compat_user_mode(regs))
+ fiq_debugger_dump_regs_aarch32(output, regs);
+ else
+ fiq_debugger_dump_regs_aarch64(output, regs);
+}
+
+#define READ_SPECIAL_REG(x) ({ \
+ u64 val; \
+ asm volatile ("mrs %0, " # x : "=r"(val)); \
+ val; \
+})
+
+void fiq_debugger_dump_allregs(struct fiq_debugger_output *output,
+ const struct pt_regs *regs)
+{
+ u32 pstate = READ_SPECIAL_REG(CurrentEl);
+ bool in_el2 = (pstate & PSR_MODE_MASK) >= PSR_MODE_EL2t;
+
+ fiq_debugger_dump_regs(output, regs);
+
+ output->printf(output, " sp_el0 %016lx\n",
+ READ_SPECIAL_REG(sp_el0));
+
+ if (in_el2)
+ output->printf(output, " sp_el1 %016lx\n",
+ READ_SPECIAL_REG(sp_el1));
+
+ output->printf(output, " elr_el1 %016lx\n",
+ READ_SPECIAL_REG(elr_el1));
+
+ output->printf(output, " spsr_el1 %08lx\n",
+ READ_SPECIAL_REG(spsr_el1));
+
+ if (in_el2) {
+ output->printf(output, " spsr_irq %08lx\n",
+ READ_SPECIAL_REG(spsr_irq));
+ output->printf(output, " spsr_abt %08lx\n",
+ READ_SPECIAL_REG(spsr_abt));
+ output->printf(output, " spsr_und %08lx\n",
+ READ_SPECIAL_REG(spsr_und));
+ output->printf(output, " spsr_fiq %08lx\n",
+ READ_SPECIAL_REG(spsr_fiq));
+ output->printf(output, " spsr_el2 %08lx\n",
+ READ_SPECIAL_REG(elr_el2));
+ output->printf(output, " spsr_el2 %08lx\n",
+ READ_SPECIAL_REG(spsr_el2));
+ }
+}
+
+struct stacktrace_state {
+ struct fiq_debugger_output *output;
+ unsigned int depth;
+};
+
+static int report_trace(struct stackframe *frame, void *d)
+{
+ struct stacktrace_state *sts = d;
+
+ if (sts->depth) {
+ sts->output->printf(sts->output, "%pF:\n", frame->pc);
+ sts->output->printf(sts->output,
+ " pc %016lx sp %016lx fp %016lx\n",
+ frame->pc, frame->sp, frame->fp);
+ sts->depth--;
+ return 0;
+ }
+ sts->output->printf(sts->output, " ...\n");
+
+ return sts->depth == 0;
+}
+
+void fiq_debugger_dump_stacktrace(struct fiq_debugger_output *output,
+ const struct pt_regs *regs, unsigned int depth, void *ssp)
+{
+ struct thread_info *real_thread_info = THREAD_INFO(ssp);
+ struct stacktrace_state sts;
+
+ sts.depth = depth;
+ sts.output = output;
+ *current_thread_info() = *real_thread_info;
+
+ if (!current)
+ output->printf(output, "current NULL\n");
+ else
+ output->printf(output, "pid: %d comm: %s\n",
+ current->pid, current->comm);
+ fiq_debugger_dump_regs(output, regs);
+
+ if (!user_mode(regs)) {
+ struct stackframe frame;
+ frame.fp = regs->regs[29];
+ frame.sp = regs->sp;
+ frame.pc = regs->pc;
+ output->printf(output, "\n");
+ walk_stackframe(current, &frame, report_trace, &sts);
+ }
+}
diff --git a/drivers/staging/android/fiq_debugger/fiq_debugger_priv.h b/drivers/staging/android/fiq_debugger/fiq_debugger_priv.h
new file mode 100644
index 000000000000..d5d051f727a8
--- /dev/null
+++ b/drivers/staging/android/fiq_debugger/fiq_debugger_priv.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2014 Google, Inc.
+ * Author: Colin Cross <ccross@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _FIQ_DEBUGGER_PRIV_H_
+#define _FIQ_DEBUGGER_PRIV_H_
+
+#define THREAD_INFO(sp) ((struct thread_info *) \
+ ((unsigned long)(sp) & ~(THREAD_SIZE - 1)))
+
+struct fiq_debugger_output {
+ void (*printf)(struct fiq_debugger_output *output, const char *fmt, ...);
+};
+
+struct pt_regs;
+
+void fiq_debugger_dump_pc(struct fiq_debugger_output *output,
+ const struct pt_regs *regs);
+void fiq_debugger_dump_regs(struct fiq_debugger_output *output,
+ const struct pt_regs *regs);
+void fiq_debugger_dump_allregs(struct fiq_debugger_output *output,
+ const struct pt_regs *regs);
+void fiq_debugger_dump_stacktrace(struct fiq_debugger_output *output,
+ const struct pt_regs *regs, unsigned int depth, void *ssp);
+
+#endif
diff --git a/drivers/staging/android/fiq_debugger/fiq_debugger_ringbuf.h b/drivers/staging/android/fiq_debugger/fiq_debugger_ringbuf.h
new file mode 100644
index 000000000000..10c3c5d09098
--- /dev/null
+++ b/drivers/staging/android/fiq_debugger/fiq_debugger_ringbuf.h
@@ -0,0 +1,94 @@
+/*
+ * drivers/staging/android/fiq_debugger/fiq_debugger_ringbuf.h
+ *
+ * simple lockless ringbuffer
+ *
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+struct fiq_debugger_ringbuf {
+ int len;
+ int head;
+ int tail;
+ u8 buf[];
+};
+
+
+static inline struct fiq_debugger_ringbuf *fiq_debugger_ringbuf_alloc(int len)
+{
+ struct fiq_debugger_ringbuf *rbuf;
+
+ rbuf = kzalloc(sizeof(*rbuf) + len, GFP_KERNEL);
+ if (rbuf == NULL)
+ return NULL;
+
+ rbuf->len = len;
+ rbuf->head = 0;
+ rbuf->tail = 0;
+ smp_mb();
+
+ return rbuf;
+}
+
+static inline void fiq_debugger_ringbuf_free(struct fiq_debugger_ringbuf *rbuf)
+{
+ kfree(rbuf);
+}
+
+static inline int fiq_debugger_ringbuf_level(struct fiq_debugger_ringbuf *rbuf)
+{
+ int level = rbuf->head - rbuf->tail;
+
+ if (level < 0)
+ level = rbuf->len + level;
+
+ return level;
+}
+
+static inline int fiq_debugger_ringbuf_room(struct fiq_debugger_ringbuf *rbuf)
+{
+ return rbuf->len - fiq_debugger_ringbuf_level(rbuf) - 1;
+}
+
+static inline u8
+fiq_debugger_ringbuf_peek(struct fiq_debugger_ringbuf *rbuf, int i)
+{
+ return rbuf->buf[(rbuf->tail + i) % rbuf->len];
+}
+
+static inline int
+fiq_debugger_ringbuf_consume(struct fiq_debugger_ringbuf *rbuf, int count)
+{
+ count = min(count, fiq_debugger_ringbuf_level(rbuf));
+
+ rbuf->tail = (rbuf->tail + count) % rbuf->len;
+ smp_mb();
+
+ return count;
+}
+
+static inline int
+fiq_debugger_ringbuf_push(struct fiq_debugger_ringbuf *rbuf, u8 datum)
+{
+ if (fiq_debugger_ringbuf_room(rbuf) == 0)
+ return 0;
+
+ rbuf->buf[rbuf->head] = datum;
+ smp_mb();
+ rbuf->head = (rbuf->head + 1) % rbuf->len;
+ smp_mb();
+
+ return 1;
+}
diff --git a/drivers/staging/android/fiq_debugger/fiq_watchdog.c b/drivers/staging/android/fiq_debugger/fiq_watchdog.c
new file mode 100644
index 000000000000..194b54138417
--- /dev/null
+++ b/drivers/staging/android/fiq_debugger/fiq_watchdog.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2014 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/pstore_ram.h>
+
+#include "fiq_watchdog.h"
+#include "fiq_debugger_priv.h"
+
+static DEFINE_RAW_SPINLOCK(fiq_watchdog_lock);
+
+static void fiq_watchdog_printf(struct fiq_debugger_output *output,
+ const char *fmt, ...)
+{
+ char buf[256];
+ va_list ap;
+ int len;
+
+ va_start(ap, fmt);
+ len = vscnprintf(buf, sizeof(buf), fmt, ap);
+ va_end(ap);
+
+ ramoops_console_write_buf(buf, len);
+}
+
+struct fiq_debugger_output fiq_watchdog_output = {
+ .printf = fiq_watchdog_printf,
+};
+
+void fiq_watchdog_triggered(const struct pt_regs *regs, void *svc_sp)
+{
+ char msg[24];
+ int len;
+
+ raw_spin_lock(&fiq_watchdog_lock);
+
+ len = scnprintf(msg, sizeof(msg), "watchdog fiq cpu %d\n",
+ THREAD_INFO(svc_sp)->cpu);
+ ramoops_console_write_buf(msg, len);
+
+ fiq_debugger_dump_stacktrace(&fiq_watchdog_output, regs, 100, svc_sp);
+
+ raw_spin_unlock(&fiq_watchdog_lock);
+}
diff --git a/drivers/staging/android/fiq_debugger/fiq_watchdog.h b/drivers/staging/android/fiq_debugger/fiq_watchdog.h
new file mode 100644
index 000000000000..c6b507f8d976
--- /dev/null
+++ b/drivers/staging/android/fiq_debugger/fiq_watchdog.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2014 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _FIQ_WATCHDOG_H_
+#define _FIQ_WATCHDOG_H_
+
+void fiq_watchdog_triggered(const struct pt_regs *regs, void *svc_sp);
+
+#endif