blob: d06863881f0214082451c0f71a9c20736bb3f97b [file] [log] [blame]
/*
* 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/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>
#include <asm/fiq_debugger.h>
#include <asm/fiq_glue.h>
#include <asm/stacktrace.h>
#include <linux/uaccess.h>
#include "fiq_debugger_ringbuf.h"
#define DEBUG_MAX 64
#define MAX_UNHANDLED_FIQ_COUNT 1000000
#define MAX_FIQ_DEBUGGER_PORTS 4
#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;
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_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_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;
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);
#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_putc(struct fiq_debugger_state *state, char c)
{
state->pdata->uart_putc(state->pdev, c);
}
static void debug_puts(struct fiq_debugger_state *state, char *s)
{
unsigned c;
while ((c = *s++)) {
if (c == '\n')
debug_putc(state, '\r');
debug_putc(state, 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;
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);
}
}
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)
{
if ((rq == 'g' || rq == 'G') && !fiq_kgdb_enable) {
debug_printf(state, "sysrq-g blocked\n");
return;
}
begin_syslog_dump(state);
handle_sysrq(rq);
end_syslog_dump(state);
}
#ifdef CONFIG_KGDB
static void do_kgdb(struct fiq_debugger_state *state)
{
if (!fiq_kgdb_enable) {
debug_printf(state, "kgdb through fiq debugger not enabled\n");
return;
}
debug_printf(state, "enabling console and triggering kgdb\n");
state->console_enable = true;
handle_sysrq('g');
}
#endif
static void debug_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') {
debug_printf(state, "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 debug_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 {
debug_printf(state, "unknown work command '%s'\n", work_cmd);
}
}
/* 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]);
#ifdef CONFIG_KGDB
if (!strcmp(cmd, "kgdb"))
do_kgdb(state);
#endif
if (!strncmp(cmd, "reboot", 6))
debug_schedule_work(state, cmd);
}
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 [<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");
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");
#ifdef CONFIG_KGDB
debug_printf(state, " kgdb Enter kernel debugger\n");
#endif
}
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 (!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")) {
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")) {
debug_printf(state, "console mode\n");
debug_uart_flush(state);
state->console_enable = true;
} 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);
if (!state->console_enable)
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;
debug_putc(state, c);
}
} else if ((c == 8) || (c == 127)) {
if (state->debug_count > 0) {
state->debug_count--;
debug_putc(state, 8);
debug_putc(state, ' ');
debug_putc(state, 8);
}
} else if ((c == 13) || (c == 10)) {
if (c == '\r' || (c == '\n' && last_c != '\r')) {
debug_putc(state, '\r');
debug_putc(state, '\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;
}
if (!state->console_enable)
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)
{
*index = co->index;
return fiq_tty_driver;
}
static void debug_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;
debug_uart_enable(state);
spin_lock_irqsave(&state->console_lock, flags);
while (count--) {
if (*s == '\n')
debug_putc(state, '\r');
debug_putc(state, *s++);
}
debug_uart_flush(state);
spin_unlock_irqrestore(&state->console_lock, flags);
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)
{
int line = tty->index;
struct fiq_debugger_state **states = tty->driver->driver_state;
struct fiq_debugger_state *state = states[line];
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);
spin_lock_irq(&state->console_lock);
for (i = 0; i < count; i++)
debug_putc(state, *buf++);
spin_unlock_irq(&state->console_lock);
debug_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 *state = driver->ttys[line]->driver_data;
int c = NO_POLL_CHAR;
debug_uart_enable(state);
if (debug_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 = debug_getc(state);
if (c == FIQ_DEBUGGER_NO_CHAR)
c = NO_POLL_CHAR;
}
debug_uart_disable(state);
return c;
}
static void fiq_tty_poll_put_char(struct tty_driver *driver, int line, char ch)
{
struct fiq_debugger_state *state = driver->ttys[line]->driver_data;
debug_uart_enable(state);
debug_putc(state, ch);
debug_uart_disable(state);
}
#endif
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_dev = tty_register_device(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);
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");
INIT_WORK(&state->work, debug_work);
spin_lock_init(&state->work_lock);
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)
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:
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)
{
fiq_debugger_tty_init();
return platform_driver_register(&fiq_debugger_driver);
}
postcore_initcall(fiq_debugger_init);