[AVR32] NMI debugging

Change the NMI handler to use the die notifier chain to signal anyone
who cares. Add a simple "nmi debugger" which hooks into this chain and
that may dump registers, task state, etc. when it happens.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

1 files changed, 18 insertions, 3 deletions

diff --git a/arch/avr32/kernel/traps.c b/arch/avr32/kernel/traps.c
index 870c075e6314..cf6f686d9b0b 100644
--- a/arch/avr32/kernel/traps.c
+++ b/arch/avr32/kernel/traps.c
@@ -9,6 +9,7 @@
 #include <linux/bug.h>
 #include <linux/init.h>
 #include <linux/kallsyms.h>
+#include <linux/kdebug.h>
 #include <linux/module.h>
 #include <linux/notifier.h>
 #include <linux/sched.h>
@@ -107,9 +108,23 @@ void _exception(long signr, struct pt_regs *regs, int code,
 
 asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs)
 {
-        printk(KERN_ALERT "Got Non-Maskable Interrupt, dumping regs\n");
-        show_regs_log_lvl(regs, KERN_ALERT);
-        show_stack_log_lvl(current, regs->sp, regs, KERN_ALERT);
+        int ret;
+
+        nmi_enter();
+
+        ret = notify_die(DIE_NMI, "NMI", regs, 0, ecr, SIGINT);
+        switch (ret) {
+        case NOTIFY_OK:
+        case NOTIFY_STOP:
+                return;
+        case NOTIFY_BAD:
+                die("Fatal Non-Maskable Interrupt", regs, SIGINT);
+        default:
+                break;
+        }
+
+        printk(KERN_ALERT "Got NMI, but nobody cared. Disabling...\n");
+        nmi_disable();
 }
 
 asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs)