[ARM] fiq debugger: Allow selection of target cpu

Change-Id: I676bac08ba12dfa506aea16800fc80432b4bc83d
Signed-off-by: Colin Cross <ccross@android.com>

diff --git a/arch/arm/common/fiq_debugger.c b/arch/arm/common/fiq_debugger.c
index 1ba345d..3300538 100644 (file)
--- a/arch/arm/common/fiq_debugger.c
+++ b/arch/arm/common/fiq_debugger.c
@@ -44,6 +44,10 @@
 #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;
@@ -70,6 +74,9 @@ struct fiq_debugger_state {
        bool uart_clk_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;
@@ -388,8 +395,7 @@ 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 thread_info *real_thread_info = THREAD_INFO(ssp);
        struct stacktrace_state sts;
 
        sts.depth = depth;
@@ -449,6 +455,15 @@ static void debug_exec(struct fiq_debugger_state *state,
        } 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)
+                       state->current_cpu = 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,
@@ -552,6 +567,26 @@ static void debug_fiq(struct fiq_glue_handler *h, void *regs, void *svc_sp)
        int c;
        static int last_c;
        int count = 0;
+       unsigned int this_cpu = THREAD_INFO(svc_sp)->cpu;
+
+       if (this_cpu != state->current_cpu) {
+               if (state->in_fiq)
+                       return;
+
+               if (atomic_inc_return(&state->unhandled_fiq_count) !=
+                                       MAX_UNHANDLED_FIQ_COUNT)
+                       return;
+
+               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);
+               state->current_cpu = this_cpu;
+               return;
+       }
+
+       state->in_fiq = true;
 
        while ((c = debug_getc(state)) != FIQ_DEBUGGER_NO_CHAR) {
                count++;
@@ -606,6 +641,9 @@ static void debug_fiq(struct fiq_glue_handler *h, void *regs, void *svc_sp)
        /* poke sleep timer if necessary */
        if (state->debug_enable && !state->no_sleep)
                debug_force_irq(state);
+
+       atomic_set(&state->unhandled_fiq_count, 0);
+       state->in_fiq = false;
 }
 
 static void debug_resume(struct fiq_glue_handler *h)