--- /dev/null
+/*
+ * arch/arm/common/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/irq.h>
+#include <linux/delay.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>
+
+#include <asm/fiq_debugger.h>
+#include <asm/fiq_glue.h>
+#include <asm/stacktrace.h>
+
+#include <mach/system.h>
+
+#include <linux/uaccess.h>
+
+#include "fiq_debugger_ringbuf.h"
+
+#define DEBUG_MAX 64
+#define MAX_UNHANDLED_FIQ_COUNT 1000000
+
+#define THREAD_INFO(sp) ((struct thread_info *) \
+ ((unsigned long)(sp) & ~(THREAD_SIZE - 1)))
+
+struct fiq_debugger_state {
+ struct fiq_glue_handler handler;
+
+ 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;
+
+#ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
+ struct console console;
+ struct tty_driver *tty_driver;
+ struct tty_struct *tty;
+ int tty_open_count;
+ 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_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
+
+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);
+
+#ifdef CONFIG_FIQ_DEBUGGER_WAKEUP_IRQ_ALWAYS_ON
+static inline void enable_wakeup_irq(struct fiq_debugger_state *state) {}
+static inline void disable_wakeup_irq(struct fiq_debugger_state *state) {}
+#else
+static inline void 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 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 bool inline debug_have_fiq(struct fiq_debugger_state *state)
+{
+ return (state->fiq >= 0);
+}
+
+static void debug_force_irq(struct fiq_debugger_state *state)
+{
+ unsigned int irq = state->signal_irq;
+
+ if (WARN_ON(!debug_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));
+ }
+}
+
+static void debug_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 debug_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 debug_uart_flush(struct fiq_debugger_state *state)
+{
+ if (state->pdata->uart_flush)
+ state->pdata->uart_flush(state->pdev);
+}
+
+static void debug_puts(struct fiq_debugger_state *state, char *s)
+{
+ unsigned c;
+ while ((c = *s++)) {
+ if (c == '\n')
+ state->pdata->uart_putc(state->pdev, '\r');
+ state->pdata->uart_putc(state->pdev, c);
+ }
+}
+
+static void debug_prompt(struct fiq_debugger_state *state)
+{
+ debug_puts(state, "debug> ");
+}
+
+int log_buf_copy(char *dest, int idx, int len);
+static void dump_kernel_log(struct fiq_debugger_state *state)
+{
+ char buf[1024];
+ int idx = 0;
+ int ret;
+ int saved_oip;
+
+ /* setting oops_in_progress prevents log_buf_copy()
+ * from trying to take a spinlock which will make it
+ * very unhappy in some cases...
+ */
+ saved_oip = oops_in_progress;
+ oops_in_progress = 1;
+ for (;;) {
+ ret = log_buf_copy(buf, idx, 1023);
+ if (ret <= 0)
+ break;
+ buf[ret] = 0;
+ debug_puts(state, buf);
+ idx += ret;
+ }
+ oops_in_progress = saved_oip;
+}
+
+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 "???";
+ }
+}
+
+static int debug_printf(void *cookie, const char *fmt, ...)
+{
+ struct fiq_debugger_state *state = cookie;
+ char buf[256];
+ va_list ap;
+
+ va_start(ap, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, ap);
+ va_end(ap);
+
+ debug_puts(state, buf);
+ return state->debug_abort;
+}
+
+/* Safe outside fiq context */
+static int debug_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);
+ debug_puts(state, buf);
+ debug_uart_flush(state);
+ local_irq_restore(irq_flags);
+ return state->debug_abort;
+}
+
+static void dump_regs(struct fiq_debugger_state *state, unsigned *regs)
+{
+ debug_printf(state, " r0 %08x r1 %08x r2 %08x r3 %08x\n",
+ regs[0], regs[1], regs[2], regs[3]);
+ debug_printf(state, " r4 %08x r5 %08x r6 %08x r7 %08x\n",
+ regs[4], regs[5], regs[6], regs[7]);
+ debug_printf(state, " r8 %08x r9 %08x r10 %08x r11 %08x mode %s\n",
+ regs[8], regs[9], regs[10], regs[11],
+ mode_name(regs[16]));
+ if ((regs[16] & MODE_MASK) == USR_MODE)
+ debug_printf(state, " ip %08x sp %08x lr %08x pc %08x "
+ "cpsr %08x\n", regs[12], regs[13], regs[14],
+ regs[15], regs[16]);
+ else
+ debug_printf(state, " ip %08x sp %08x lr %08x pc %08x "
+ "cpsr %08x spsr %08x\n", regs[12], regs[13],
+ regs[14], regs[15], regs[16], regs[17]);
+}
+
+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;
+};
+
+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");
+}
+
+
+static void dump_allregs(struct fiq_debugger_state *state, unsigned *regs)
+{
+ struct mode_regs mode_regs;
+ dump_regs(state, regs);
+ get_mode_regs(&mode_regs);
+ debug_printf(state, " svc: sp %08x lr %08x spsr %08x\n",
+ mode_regs.sp_svc, mode_regs.lr_svc, mode_regs.spsr_svc);
+ debug_printf(state, " abt: sp %08x lr %08x spsr %08x\n",
+ mode_regs.sp_abt, mode_regs.lr_abt, mode_regs.spsr_abt);
+ debug_printf(state, " und: sp %08x lr %08x spsr %08x\n",
+ mode_regs.sp_und, mode_regs.lr_und, mode_regs.spsr_und);
+ debug_printf(state, " irq: sp %08x lr %08x spsr %08x\n",
+ mode_regs.sp_irq, mode_regs.lr_irq, mode_regs.spsr_irq);
+ debug_printf(state, " fiq: r8 %08x r9 %08x r10 %08x r11 %08x "
+ "r12 %08x\n",
+ mode_regs.r8_fiq, mode_regs.r9_fiq, mode_regs.r10_fiq,
+ mode_regs.r11_fiq, mode_regs.r12_fiq);
+ debug_printf(state, " fiq: sp %08x lr %08x spsr %08x\n",
+ mode_regs.sp_fiq, mode_regs.lr_fiq, mode_regs.spsr_fiq);
+}
+
+static void dump_irqs(struct fiq_debugger_state *state)
+{
+ int n;
+ unsigned int cpu;
+
+ debug_printf(state, "irqnr total since-last status name\n");
+ for (n = 0; n < NR_IRQS; n++) {
+ struct irqaction *act = irq_desc[n].action;
+ if (!act && !kstat_irqs(n))
+ continue;
+ debug_printf(state, "%5d: %10u %11u %8x %s\n", n,
+ kstat_irqs(n),
+ kstat_irqs(n) - state->last_irqs[n],
+ irq_desc[n].status_use_accessors,
+ (act && act->name) ? act->name : "???");
+ state->last_irqs[n] = kstat_irqs(n);
+ }
+
+ for (cpu = 0; cpu < NR_CPUS; cpu++) {
+
+ debug_printf(state, "LOC %d: %10u %11u\n", cpu,
+ __IRQ_STAT(cpu, local_timer_irqs),
+ __IRQ_STAT(cpu, local_timer_irqs) -
+ state->last_local_timer_irqs[cpu]);
+ state->last_local_timer_irqs[cpu] =
+ __IRQ_STAT(cpu, local_timer_irqs);
+ }
+}
+
+struct stacktrace_state {
+ struct fiq_debugger_state *state;
+ unsigned int depth;
+};
+
+static int report_trace(struct stackframe *frame, void *d)
+{
+ struct stacktrace_state *sts = d;
+
+ if (sts->depth) {
+ debug_printf(sts->state,
+ " 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;
+ }
+ debug_printf(sts->state, " ...\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_state *state,
+ 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))) {
+ debug_printf(state, " invalid frame pointer %p\n", tail);
+ return NULL;
+ }
+ if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail))) {
+ debug_printf(state,
+ " failed to copy frame pointer %p\n", tail);
+ return NULL;
+ }
+
+ debug_printf(state, " %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 dump_stacktrace(struct fiq_debugger_state *state,
+ struct pt_regs * const 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.state = state;
+ *current_thread_info() = *real_thread_info;
+
+ if (!current)
+ debug_printf(state, "current NULL\n");
+ else
+ debug_printf(state, "pid: %d comm: %s\n",
+ current->pid, current->comm);
+ dump_regs(state, (unsigned *)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;
+ debug_printf(state,
+ " 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(state, tail);
+}
+
+static void do_ps(struct fiq_debugger_state *state)
+{
+ struct task_struct *g;
+ struct task_struct *p;
+ unsigned task_state;
+ static const char stat_nam[] = "RSDTtZX";
+
+ debug_printf(state, "pid ppid prio task pc\n");
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ task_state = p->state ? __ffs(p->state) + 1 : 0;
+ debug_printf(state,
+ "%5d %5d %4d ", p->pid, p->parent->pid, p->prio);
+ debug_printf(state, "%-13.13s %c", p->comm,
+ task_state >= sizeof(stat_nam) ? '?' : stat_nam[task_state]);
+ if (task_state == TASK_RUNNING)
+ debug_printf(state, " running\n");
+ else
+ debug_printf(state, " %08lx\n", thread_saved_pc(p));
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+}
+
+#ifdef CONFIG_FIQ_DEBUGGER_CONSOLE
+static void begin_syslog_dump(struct fiq_debugger_state *state)
+{
+ state->syslog_dumping = true;
+}
+
+static void 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 begin_syslog_dump(struct fiq_debugger_state *state)
+{
+ do_syslog(5 /* clear */, NULL, 0);
+}
+
+static void end_syslog_dump(struct fiq_debugger_state *state)
+{
+ char buf[128];
+ int ret;
+ int idx = 0;
+
+ while (1) {
+ ret = log_buf_copy(buf, idx, sizeof(buf) - 1);
+ if (ret <= 0)
+ break;
+ buf[ret] = 0;
+ debug_printf(state, "%s", buf);
+ idx += ret;
+ }
+}
+#endif
+
+static void do_sysrq(struct fiq_debugger_state *state, char rq)
+{
+ begin_syslog_dump(state);
+ handle_sysrq(rq);
+ end_syslog_dump(state);
+}
+
+/* This function CANNOT be called in FIQ context */
+static void debug_irq_exec(struct fiq_debugger_state *state, char *cmd)
+{
+ if (!strcmp(cmd, "ps"))
+ do_ps(state);
+ if (!strcmp(cmd, "sysrq"))
+ do_sysrq(state, 'h');
+ if (!strncmp(cmd, "sysrq ", 6))
+ do_sysrq(state, cmd[6]);
+}
+
+static void debug_help(struct fiq_debugger_state *state)
+{
+ debug_printf(state, "FIQ Debugger commands:\n"
+ " pc PC status\n"
+ " regs Register dump\n"
+ " allregs Extended Register dump\n"
+ " bt Stack trace\n"
+ " reboot Reboot\n"
+ " irqs Interupt status\n"
+ " kmsg Kernel log\n"
+ " version Kernel version\n");
+ debug_printf(state, " 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");
+ debug_printf(state, " ps Process list\n"
+ " sysrq sysrq options\n"
+ " sysrq <param> Execute sysrq with <param>\n");
+}
+
+static void 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 switch_cpu(struct fiq_debugger_state *state, int cpu)
+{
+ if (!debug_have_fiq(state))
+ smp_call_function_single(cpu, take_affinity, state, false);
+ state->current_cpu = cpu;
+}
+
+static bool debug_fiq_exec(struct fiq_debugger_state *state,
+ const char *cmd, unsigned *regs, void *svc_sp)
+{
+ bool signal_helper = false;
+
+ if (!strcmp(cmd, "help") || !strcmp(cmd, "?")) {
+ debug_help(state);
+ } else if (!strcmp(cmd, "pc")) {
+ debug_printf(state, " pc %08x cpsr %08x mode %s\n",
+ regs[15], regs[16], mode_name(regs[16]));
+ } else if (!strcmp(cmd, "regs")) {
+ dump_regs(state, regs);
+ } else if (!strcmp(cmd, "allregs")) {
+ dump_allregs(state, regs);
+ } else if (!strcmp(cmd, "bt")) {
+ dump_stacktrace(state, (struct pt_regs *)regs, 100, svc_sp);
+ } else if (!strcmp(cmd, "reboot")) {
+ arch_reset(0, 0);
+ } else if (!strcmp(cmd, "irqs")) {
+ dump_irqs(state);
+ } else if (!strcmp(cmd, "kmsg")) {
+ dump_kernel_log(state);
+ } else if (!strcmp(cmd, "version")) {
+ debug_printf(state, "%s\n", linux_banner);
+ } else if (!strcmp(cmd, "sleep")) {
+ state->no_sleep = false;
+ debug_printf(state, "enabling sleep\n");
+ } else if (!strcmp(cmd, "nosleep")) {
+ state->no_sleep = true;
+ debug_printf(state, "disabling sleep\n");
+ } else if (!strcmp(cmd, "console")) {
+ state->console_enable = true;
+ debug_printf(state, "console mode\n");
+ } else if (!strcmp(cmd, "cpu")) {
+ debug_printf(state, "cpu %d\n", state->current_cpu);
+ } else if (!strncmp(cmd, "cpu ", 4)) {
+ unsigned long cpu = 0;
+ if (strict_strtoul(cmd + 4, 10, &cpu) == 0)
+ switch_cpu(state, cpu);
+ else
+ debug_printf(state, "invalid cpu\n");
+ debug_printf(state, "cpu %d\n", state->current_cpu);
+ } else {
+ if (state->debug_busy) {
+ debug_printf(state,
+ "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)
+ debug_prompt(state);
+
+ return signal_helper;
+}
+
+static void 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;
+ debug_printf_nfiq(state, "suspending fiq debugger\n");
+ }
+ state->ignore_next_wakeup_irq = true;
+ debug_uart_disable(state);
+ state->uart_enabled = false;
+ enable_wakeup_irq(state);
+ }
+ wake_unlock(&state->debugger_wake_lock);
+ spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
+}
+
+static void 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);
+ debug_uart_enable(state);
+ state->uart_enabled = true;
+ disable_wakeup_irq(state);
+ mod_timer(&state->sleep_timer, jiffies + HZ / 2);
+ }
+ spin_unlock_irqrestore(&state->sleep_timer_lock, flags);
+}
+
+static irqreturn_t wakeup_irq_handler(int irq, void *dev)
+{
+ struct fiq_debugger_state *state = dev;
+
+ if (!state->no_sleep)
+ debug_puts(state, "WAKEUP\n");
+ handle_wakeup(state);
+
+ return IRQ_HANDLED;
+}
+
+
+static void debug_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);
+ }
+#if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
+ if (state->tty) {
+ 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, 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);
+ }
+#endif
+ if (state->debug_busy) {
+ debug_irq_exec(state, state->debug_cmd);
+ debug_prompt(state);
+ state->debug_busy = 0;
+ }
+}
+
+static int debug_getc(struct fiq_debugger_state *state)
+{
+ return state->pdata->uart_getc(state->pdev);
+}
+
+static bool debug_handle_uart_interrupt(struct fiq_debugger_state *state,
+ int this_cpu, void *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;
+
+ debug_printf(state, "fiq_debugger: cpu %d not responding, "
+ "reverting to cpu %d\n", state->current_cpu,
+ this_cpu);
+
+ atomic_set(&state->unhandled_fiq_count, 0);
+ switch_cpu(state, this_cpu);
+ return false;
+ }
+
+ state->in_fiq = true;
+
+ while ((c = debug_getc(state)) != FIQ_DEBUGGER_NO_CHAR) {
+ count++;
+ if (!state->debug_enable) {
+ if ((c == 13) || (c == 10)) {
+ state->debug_enable = true;
+ state->debug_count = 0;
+ debug_prompt(state);
+ }
+ } else if (c == FIQ_DEBUGGER_BREAK) {
+ state->console_enable = false;
+ debug_puts(state, "fiq debugger mode\n");
+ state->debug_count = 0;
+ debug_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;
+ state->pdata->uart_putc(state->pdev, c);
+ }
+ } else if ((c == 8) || (c == 127)) {
+ if (state->debug_count > 0) {
+ state->debug_count--;
+ state->pdata->uart_putc(state->pdev, 8);
+ state->pdata->uart_putc(state->pdev, ' ');
+ state->pdata->uart_putc(state->pdev, 8);
+ }
+ } else if ((c == 13) || (c == 10)) {
+ if (c == '\r' || (c == '\n' && last_c != '\r')) {
+ state->pdata->uart_putc(state->pdev, '\r');
+ state->pdata->uart_putc(state->pdev, '\n');
+ }
+ if (state->debug_count) {
+ state->debug_buf[state->debug_count] = 0;
+ state->debug_count = 0;
+ signal_helper |=
+ debug_fiq_exec(state, state->debug_buf,
+ regs, svc_sp);
+ } else {
+ debug_prompt(state);
+ }
+ }
+ last_c = c;
+ }
+ debug_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;
+}
+
+static void debug_fiq(struct fiq_glue_handler *h, void *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 = debug_handle_uart_interrupt(state, this_cpu, regs, svc_sp);
+ if (need_irq)
+ debug_force_irq(state);
+}
+
+/*
+ * 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 debug_uart_irq(int irq, void *dev)
+{
+ struct fiq_debugger_state *state = dev;
+ bool not_done;
+
+ handle_wakeup(state);
+
+ /* handle the debugger irq in regular context */
+ not_done = debug_handle_uart_interrupt(state, smp_processor_id(),
+ get_irq_regs(),
+ current_thread_info());
+ if (not_done)
+ debug_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 debug_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);
+
+ debug_handle_irq_context(state);
+
+ return IRQ_HANDLED;
+}
+
+static void debug_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);
+}
+
+#if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
+struct tty_driver *debug_console_device(struct console *co, int *index)
+{
+ struct fiq_debugger_state *state;
+ state = container_of(co, struct fiq_debugger_state, console);
+ *index = 0;
+ return state->tty_driver;
+}
+
+static void debug_console_write(struct console *co,
+ const char *s, unsigned int count)
+{
+ struct fiq_debugger_state *state;
+
+ state = container_of(co, struct fiq_debugger_state, console);
+
+ if (!state->console_enable && !state->syslog_dumping)
+ return;
+
+ debug_uart_enable(state);
+ while (count--) {
+ if (*s == '\n')
+ state->pdata->uart_putc(state->pdev, '\r');
+ state->pdata->uart_putc(state->pdev, *s++);
+ }
+ debug_uart_flush(state);
+ debug_uart_disable(state);
+}
+
+static struct console fiq_debugger_console = {
+ .name = "ttyFIQ",
+ .device = debug_console_device,
+ .write = debug_console_write,
+ .flags = CON_PRINTBUFFER | CON_ANYTIME | CON_ENABLED,
+};
+
+int fiq_tty_open(struct tty_struct *tty, struct file *filp)
+{
+ struct fiq_debugger_state *state = tty->driver->driver_state;
+ if (state->tty_open_count++)
+ return 0;
+
+ tty->driver_data = state;
+ state->tty = tty;
+ return 0;
+}
+
+void fiq_tty_close(struct tty_struct *tty, struct file *filp)
+{
+ struct fiq_debugger_state *state = tty->driver_data;
+ if (--state->tty_open_count)
+ return;
+ state->tty = NULL;
+}
+
+int fiq_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
+{
+ int i;
+ struct fiq_debugger_state *state = tty->driver_data;
+
+ if (!state->console_enable)
+ return count;
+
+ debug_uart_enable(state);
+ for (i = 0; i < count; i++)
+ state->pdata->uart_putc(state->pdev, *buf++);
+ debug_uart_disable(state);
+
+ return count;
+}
+
+int fiq_tty_write_room(struct tty_struct *tty)
+{
+ return 1024;
+}
+
+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,
+};
+
+static int fiq_debugger_tty_init(struct fiq_debugger_state *state)
+{
+ int ret = -EINVAL;
+
+ state->tty_driver = alloc_tty_driver(1);
+ if (!state->tty_driver) {
+ pr_err("Failed to allocate fiq debugger tty\n");
+ return -ENOMEM;
+ }
+
+ state->tty_driver->owner = THIS_MODULE;
+ state->tty_driver->driver_name = "fiq-debugger";
+ state->tty_driver->name = "ttyFIQ";
+ state->tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
+ state->tty_driver->subtype = SERIAL_TYPE_NORMAL;
+ state->tty_driver->init_termios = tty_std_termios;
+ state->tty_driver->init_termios.c_cflag =
+ B115200 | CS8 | CREAD | HUPCL | CLOCAL;
+ state->tty_driver->init_termios.c_ispeed =
+ state->tty_driver->init_termios.c_ospeed = 115200;
+ state->tty_driver->flags = TTY_DRIVER_REAL_RAW;
+ tty_set_operations(state->tty_driver, &fiq_tty_driver_ops);
+ state->tty_driver->driver_state = state;
+
+ ret = tty_register_driver(state->tty_driver);
+ if (ret) {
+ pr_err("Failed to register fiq tty: %d\n", ret);
+ goto err;
+ }
+
+ 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;
+ }
+
+ pr_info("Registered FIQ tty driver %p\n", state->tty_driver);
+ return 0;
+
+err:
+ fiq_debugger_ringbuf_free(state->tty_rbuf);
+ state->tty_rbuf = NULL;
+ put_tty_driver(state->tty_driver);
+ 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 (!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);
+ setup_timer(&state->sleep_timer, 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");
+
+ platform_set_drvdata(pdev, state);
+
+ spin_lock_init(&state->sleep_timer_lock);
+
+ if (state->wakeup_irq < 0 && debug_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;
+ }
+
+ debug_printf_nfiq(state, "<hit enter %sto activate fiq debugger>\n",
+ state->no_sleep ? "" : "twice ");
+
+ if (debug_have_fiq(state)) {
+ state->handler.fiq = debug_fiq;
+ state->handler.resume = debug_resume;
+ ret = fiq_glue_register_handler(&state->handler);
+ if (ret) {
+ pr_err("%s: could not install fiq handler\n", __func__);
+ goto err_register_fiq;
+ }
+
+ pdata->fiq_enable(pdev, state->fiq, 1);
+ } else {
+ ret = request_irq(state->uart_irq, debug_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, debug_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, wakeup_irq_handler,
+ IRQF_TRIGGER_FALLING | IRQF_DISABLED,
+ "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)
+ handle_wakeup(state);
+
+#if defined(CONFIG_FIQ_DEBUGGER_CONSOLE)
+ state->console = fiq_debugger_console;
+ register_console(&state->console);
+ fiq_debugger_tty_init(state);
+#endif
+ return 0;
+
+err_register_irq:
+err_register_fiq:
+ 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,
+ },
+};
+
+static int __init fiq_debugger_init(void)
+{
+ return platform_driver_register(&fiq_debugger_driver);
+}
+
+postcore_initcall(fiq_debugger_init);
projects / firefly-linux-kernel-4.4.55.git / commitdiff