9 files changed, 133 insertions, 9 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 7936b801fe6a..76c355214dc3 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1514,7 +1514,7 @@ and is between 256 and 4096 characters. It is defined in the file
                         of returning the full 64-bit number.
                         The default is to return 64-bit inode numbers.
 
-        nmi_debug=      [KNL,AVR32] Specify one or more actions to take
+        nmi_debug=      [KNL,AVR32,SH] Specify one or more actions to take
                         when a NMI is triggered.
                         Format: [state][,regs][,debounce][,die]
 
diff --git a/arch/sh/include/asm/kdebug.h b/arch/sh/include/asm/kdebug.h
index 0b9f896f203c..985219f9759e 100644
--- a/arch/sh/include/asm/kdebug.h
+++ b/arch/sh/include/asm/kdebug.h
@@ -4,6 +4,7 @@
 /* Grossly misnamed. */
 enum die_val {
         DIE_TRAP,
+        DIE_NMI,
         DIE_OOPS,
 };
 
diff --git a/arch/sh/include/asm/system.h b/arch/sh/include/asm/system.h
index 6b272238a46e..b5c5acdc8c0e 100644
--- a/arch/sh/include/asm/system.h
+++ b/arch/sh/include/asm/system.h
@@ -169,7 +169,7 @@ BUILD_TRAP_HANDLER(breakpoint);
 BUILD_TRAP_HANDLER(singlestep);
 BUILD_TRAP_HANDLER(fpu_error);
 BUILD_TRAP_HANDLER(fpu_state_restore);
-BUILD_TRAP_HANDLER(unwinder);
+BUILD_TRAP_HANDLER(nmi);
 
 #ifdef CONFIG_BUG
 extern void handle_BUG(struct pt_regs *);
diff --git a/arch/sh/kernel/Makefile b/arch/sh/kernel/Makefile
index f37cf02ad9be..a2d0a40f3848 100644
--- a/arch/sh/kernel/Makefile
+++ b/arch/sh/kernel/Makefile
@@ -10,9 +10,10 @@ CFLAGS_REMOVE_ftrace.o = -pg
 endif
 
 obj-y   := debugtraps.o dumpstack.o idle.o io.o io_generic.o irq.o      \
-           machvec.o process_$(BITS).o ptrace_$(BITS).o setup.o         \
-           signal_$(BITS).o sys_sh.o sys_sh$(BITS).o syscalls_$(BITS).o \
-           time.o topology.o traps.o traps_$(BITS).o unwinder.o
+           machvec.o nmi_debug.o process_$(BITS).o ptrace_$(BITS).o     \
+           setup.o signal_$(BITS).o sys_sh.o sys_sh$(BITS).o            \
+           syscalls_$(BITS).o time.o topology.o traps.o                 \
+           traps_$(BITS).o unwinder.o
 
 obj-y                           += cpu/
 obj-$(CONFIG_VSYSCALL)          += vsyscall/
diff --git a/arch/sh/kernel/cpu/sh3/entry.S b/arch/sh/kernel/cpu/sh3/entry.S
index aebd33d18ff7..d1142d365925 100644
--- a/arch/sh/kernel/cpu/sh3/entry.S
+++ b/arch/sh/kernel/cpu/sh3/entry.S
@@ -532,7 +532,33 @@ ENTRY(handle_interrupt)
         mov.l   2f, r4
         mov.l   3f, r9
         mov.l   @r4, r4         ! pass INTEVT vector as arg0
+
+        shlr2   r4
+        shlr    r4
+        mov     r4, r0          ! save vector->jmp table offset for later
+
+        shlr2   r4              ! vector to IRQ# conversion
+        add     #-0x10, r4
+
+        cmp/pz  r4              ! is it a valid IRQ?
+        bt      10f
+
+        /*
+         * We got here as a result of taking the INTEVT path for something
+         * that isn't a valid hard IRQ, therefore we bypass the do_IRQ()
+         * path and special case the event dispatch instead.  This is the
+         * expected path for the NMI (and any other brilliantly implemented
+         * exception), which effectively wants regular exception dispatch
+         * but is unfortunately reported through INTEVT rather than
+         * EXPEVT.  Grr.
+         */
+        mov.l   6f, r9
+        mov.l   @(r0, r9), r9
         jmp     @r9
+         mov    r15, r8         ! trap handlers take saved regs in r8
+
+10:
+        jmp     @r9             ! Off to do_IRQ() we go.
          mov    r15, r5         ! pass saved registers as arg1
 
 ENTRY(exception_none)
diff --git a/arch/sh/kernel/cpu/sh3/ex.S b/arch/sh/kernel/cpu/sh3/ex.S
index e5a0de39a2db..46610c35c232 100644
--- a/arch/sh/kernel/cpu/sh3/ex.S
+++ b/arch/sh/kernel/cpu/sh3/ex.S
@@ -48,9 +48,7 @@ ENTRY(exception_handling_table)
         .long   system_call     ! Unconditional Trap     /* 160 */
         .long   exception_error ! reserved_instruction (filled by trap_init) /* 180 */
         .long   exception_error ! illegal_slot_instruction (filled by trap_init) /*1A0*/
-ENTRY(nmi_slot)
-        .long   kgdb_handle_exception   /* 1C0 */       ! Allow trap to debugger
-ENTRY(user_break_point_trap)
+        .long   nmi_trap_handler        /* 1C0 */       ! Allow trap to debugger
         .long   break_point_trap        /* 1E0 */
 
         /*
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index d1053392e287..60f8af4497c7 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -114,7 +114,7 @@ asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs)
 #endif
 
         irq_enter();
-        irq = irq_demux(evt2irq(irq));
+        irq = irq_demux(irq);
 
 #ifdef CONFIG_IRQSTACKS
         curctx = (union irq_ctx *)current_thread_info();
diff --git a/arch/sh/kernel/nmi_debug.c b/arch/sh/kernel/nmi_debug.c
new file mode 100644
index 000000000000..ff0abbd1e652
--- /dev/null
+++ b/arch/sh/kernel/nmi_debug.c
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/delay.h>
+#include <linux/kdebug.h>
+#include <linux/notifier.h>
+#include <linux/sched.h>
+#include <linux/hardirq.h>
+
+enum nmi_action {
+        NMI_SHOW_STATE  = 1 << 0,
+        NMI_SHOW_REGS   = 1 << 1,
+        NMI_DIE         = 1 << 2,
+        NMI_DEBOUNCE    = 1 << 3,
+};
+
+static unsigned long nmi_actions;
+
+static int nmi_debug_notify(struct notifier_block *self,
+                unsigned long val, void *data)
+{
+        struct die_args *args = data;
+
+        if (likely(val != DIE_NMI))
+                return NOTIFY_DONE;
+
+        if (nmi_actions & NMI_SHOW_STATE)
+                show_state();
+        if (nmi_actions & NMI_SHOW_REGS)
+                show_regs(args->regs);
+        if (nmi_actions & NMI_DEBOUNCE)
+                mdelay(10);
+        if (nmi_actions & NMI_DIE)
+                return NOTIFY_BAD;
+
+        return NOTIFY_OK;
+}
+
+static struct notifier_block nmi_debug_nb = {
+        .notifier_call = nmi_debug_notify,
+};
+
+static int __init nmi_debug_setup(char *str)
+{
+        char *p, *sep;
+
+        register_die_notifier(&nmi_debug_nb);
+
+        if (*str != '=')
+                return 0;
+
+        for (p = str + 1; *p; p = sep + 1) {
+                sep = strchr(p, ',');
+                if (sep)
+                        *sep = 0;
+                if (strcmp(p, "state") == 0)
+                        nmi_actions |= NMI_SHOW_STATE;
+                else if (strcmp(p, "regs") == 0)
+                        nmi_actions |= NMI_SHOW_REGS;
+                else if (strcmp(p, "debounce") == 0)
+                        nmi_actions |= NMI_DEBOUNCE;
+                else if (strcmp(p, "die") == 0)
+                        nmi_actions |= NMI_DIE;
+                else
+                        printk(KERN_WARNING "NMI: Unrecognized action `%s'\n",
+                                p);
+                if (!sep)
+                        break;
+        }
+
+        return 0;
+}
+__setup("nmi_debug", nmi_debug_setup);
diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c
index f69bd968fcca..a8396f36bd14 100644
--- a/arch/sh/kernel/traps.c
+++ b/arch/sh/kernel/traps.c
@@ -5,6 +5,7 @@
 #include <linux/signal.h>
 #include <linux/sched.h>
 #include <linux/uaccess.h>
+#include <linux/hardirq.h>
 #include <asm/unwinder.h>
 #include <asm/system.h>
 
@@ -91,3 +92,23 @@ BUILD_TRAP_HANDLER(bug)
 
         force_sig(SIGTRAP, current);
 }
+
+BUILD_TRAP_HANDLER(nmi)
+{
+        TRAP_HANDLER_DECL;
+
+        nmi_enter();
+
+        switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) {
+        case NOTIFY_OK:
+        case NOTIFY_STOP:
+                break;
+        case NOTIFY_BAD:
+                die("Fatal Non-Maskable Interrupt", regs, SIGINT);
+        default:
+                printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n");
+                break;
+        }
+
+        nmi_exit();
+}