--- /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/interrupt.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/kernel_debugger.h>
+#include <linux/kernel_stat.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/timer.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>
+
+#define DEBUG_MAX 64
+
+struct fiq_debugger_state {
+ struct fiq_glue_handler handler;
+
+ int fiq;
+ 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;
+ bool uart_clk_enabled;
+ struct wake_lock debugger_wake_lock;
+
+ unsigned int last_irqs[NR_IRQS];
+};
+
+#ifdef CONFIG_FIQ_DEBUGGER_NO_SLEEP
+static bool initial_no_sleep = true;
+#else
+static bool initial_no_sleep;
+#endif
+static bool initial_debug_enable;
+
+module_param_named(no_sleep, initial_no_sleep, bool, 0644);
+module_param_named(debug_enable, initial_debug_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 void debug_force_irq(struct fiq_debugger_state *state)
+{
+ unsigned int irq = state->signal_irq;
+ if (state->pdata->force_irq)
+ state->pdata->force_irq(state->pdev, irq);
+ else {
+ struct irq_chip *chip = get_irq_chip(irq);
+ if (chip && chip->retrigger)
+ chip->retrigger(irq);
+ }
+}
+
+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;
+ 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,
+ (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 = (struct thread_info *)
+ ((unsigned long)ssp & ~(THREAD_SIZE - 1));
+ 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 debug_exec(struct fiq_debugger_state *state,
+ const char *cmd, unsigned *regs, void *svc_sp)
+{
+ 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;
+ } else if (!strcmp(cmd, "nosleep")) {
+ state->no_sleep = true;
+ } 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;
+ }
+
+ debug_force_irq(state);
+
+ return;
+ }
+ debug_prompt(state);
+}
+
+static void sleep_timer_expired(unsigned long data)
+{
+ struct fiq_debugger_state *state = (struct fiq_debugger_state *)data;
+
+ if (state->uart_clk_enabled && !state->no_sleep) {
+ if (state->debug_enable) {
+ state->debug_enable = false;
+ debug_printf_nfiq(state, "suspending fiq debugger\n");
+ }
+ state->ignore_next_wakeup_irq = true;
+ if (state->clk)
+ clk_disable(state->clk);
+ state->uart_clk_enabled = false;
+ enable_wakeup_irq(state);
+ }
+ wake_unlock(&state->debugger_wake_lock);
+}
+
+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");
+ if (state->ignore_next_wakeup_irq)
+ state->ignore_next_wakeup_irq = false;
+ else if (!state->uart_clk_enabled) {
+ wake_lock(&state->debugger_wake_lock);
+ if (state->clk)
+ clk_enable(state->clk);
+ state->uart_clk_enabled = true;
+ disable_wakeup_irq(state);
+ mod_timer(&state->sleep_timer, jiffies + HZ / 2);
+ }
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t debug_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);
+
+ if (!state->no_sleep) {
+ wake_lock(&state->debugger_wake_lock);
+ mod_timer(&state->sleep_timer, jiffies + HZ * 5);
+ }
+ if (state->debug_busy) {
+ struct kdbg_ctxt ctxt;
+
+ ctxt.printf = debug_printf_nfiq;
+ ctxt.cookie = state;
+ kernel_debugger(&ctxt, state->debug_cmd);
+ debug_prompt(state);
+
+ state->debug_busy = 0;
+ }
+ return IRQ_HANDLED;
+}
+
+static int debug_getc(struct fiq_debugger_state *state)
+{
+ return state->pdata->uart_getc(state->pdev);
+}
+
+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);
+ int c;
+ static int last_c;
+ int count = 0;
+
+ 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 >= ' ') && (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;
+ debug_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)
+ debug_force_irq(state);
+}
+
+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);
+}
+
+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;
+
+ if (!pdata->uart_getc || !pdata->uart_putc || !pdata->fiq_enable)
+ return -EINVAL;
+
+ state = kzalloc(sizeof(*state), GFP_KERNEL);
+ state->handler.fiq = debug_fiq;
+ state->handler.resume = debug_resume;
+ 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->fiq = platform_get_irq_byname(pdev, "fiq");
+ state->signal_irq = platform_get_irq_byname(pdev, "signal");
+ state->wakeup_irq = platform_get_irq_byname(pdev, "wakeup");
+
+ if (state->wakeup_irq < 0)
+ 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;
+
+ 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 ");
+
+ ret = fiq_glue_register_handler(&state->handler);
+ if (ret) {
+ pr_err("serial_debugger: could not install fiq handler\n");
+ goto err_register_fiq;
+ }
+
+ pdata->fiq_enable(pdev, state->fiq, 1);
+
+ if (state->clk)
+ clk_disable(state->clk);
+
+ ret = request_irq(state->signal_irq, debug_irq,
+ IRQF_TRIGGER_RISING, "debug", 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)
+ wakeup_irq_handler(state->wakeup_irq, state);
+
+ return 0;
+
+err_register_fiq:
+ if (pdata->uart_free)
+ pdata->uart_free(pdev);
+err_uart_init:
+ kfree(state);
+ if (state->clk)
+ clk_put(state->clk);
+ return ret;
+}
+
+static struct platform_driver fiq_debugger_driver = {
+ .probe = fiq_debugger_probe,
+ .driver.name = "fiq_debugger",
+};
+
+static int __init fiq_debugger_init(void)
+{
+ return platform_driver_register(&fiq_debugger_driver);
+}
+
+postcore_initcall(fiq_debugger_init);
projects / kernel / kernel-mfld-blackbay.git / commitdiff