x86, NMI: Remove DIE_NMI_IPI

With priorities in place and no one really understanding the difference between
DIE_NMI and DIE_NMI_IPI, just remove DIE_NMI_IPI and convert everyone to DIE_NMI.

This also simplifies default_do_nmi() a little bit.  Instead of calling the
die_notifier in both the if and else part, just pull it out and call it before
the if-statement.  This has the side benefit of avoiding a call to the ioport
to see if there is an external NMI sitting around until after the (more frequent)
internal NMIs are dealt with.

Patch-Inspired-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294348732-15030-5-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

8 files changed, 12 insertions, 21 deletions

diff --git a/arch/x86/include/asm/kdebug.h b/arch/x86/include/asm/kdebug.h
index f23eb2528464..ca242d35e873 100644
--- a/arch/x86/include/asm/kdebug.h
+++ b/arch/x86/include/asm/kdebug.h
@@ -18,7 +18,6 @@ enum die_val {
         DIE_TRAP,
         DIE_GPF,
         DIE_CALL,
-        DIE_NMI_IPI,
         DIE_PAGE_FAULT,
         DIE_NMIUNKNOWN,
 };
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
index 8bc49f1ac7bc..79fd43ca6f96 100644
--- a/arch/x86/kernel/apic/hw_nmi.c
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -68,7 +68,6 @@ arch_trigger_all_cpu_backtrace_handler(struct notifier_block *self,
 
         switch (cmd) {
         case DIE_NMI:
-        case DIE_NMI_IPI:
                 break;
 
         default:
diff --git a/arch/x86/kernel/cpu/mcheck/mce-inject.c b/arch/x86/kernel/cpu/mcheck/mce-inject.c
index 59546c1219f9..a77971979564 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-inject.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c
@@ -25,6 +25,7 @@
 #include <linux/gfp.h>
 #include <asm/mce.h>
 #include <asm/apic.h>
+#include <asm/nmi.h>
 
 /* Update fake mce registers on current CPU. */
 static void inject_mce(struct mce *m)
@@ -83,7 +84,7 @@ static int mce_raise_notify(struct notifier_block *self,
         struct die_args *args = (struct die_args *)data;
         int cpu = smp_processor_id();
         struct mce *m = &__get_cpu_var(injectm);
-        if (val != DIE_NMI_IPI || !cpumask_test_cpu(cpu, mce_inject_cpumask))
+        if (val != DIE_NMI || !cpumask_test_cpu(cpu, mce_inject_cpumask))
                 return NOTIFY_DONE;
         cpumask_clear_cpu(cpu, mce_inject_cpumask);
         if (m->inject_flags & MCJ_EXCEPTION)
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 5e14b5e5fb81..c71bae43a51b 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1268,7 +1268,6 @@ perf_event_nmi_handler(struct notifier_block *self,
 
         switch (cmd) {
         case DIE_NMI:
-        case DIE_NMI_IPI:
                 break;
         case DIE_NMIUNKNOWN:
                 this_nmi = percpu_read(irq_stat.__nmi_count);
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index d43c84183d8f..a4130005028a 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -526,10 +526,6 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd)
                 }
                 return NOTIFY_DONE;
 
-        case DIE_NMI_IPI:
-                /* Just ignore, we will handle the roundup on DIE_NMI. */
-                return NOTIFY_DONE;
-
         case DIE_NMIUNKNOWN:
                 if (was_in_debug_nmi[raw_smp_processor_id()]) {
                         was_in_debug_nmi[raw_smp_processor_id()] = 0;
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 9c1c83e4a742..fc7aae1e2bc7 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -18,6 +18,7 @@
 #include <asm/pci_x86.h>
 #include <asm/virtext.h>
 #include <asm/cpu.h>
+#include <asm/nmi.h>
 
 #ifdef CONFIG_X86_32
 # include <linux/ctype.h>
@@ -747,7 +748,7 @@ static int crash_nmi_callback(struct notifier_block *self,
 {
         int cpu;
 
-        if (val != DIE_NMI_IPI)
+        if (val != DIE_NMI)
                 return NOTIFY_OK;
 
         cpu = raw_smp_processor_id();
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index c7fd1cea0374..23f6ac05d04c 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -394,6 +394,14 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
         unsigned char reason = 0;
         int cpu;
 
+        /*
+         * CPU-specific NMI must be processed before non-CPU-specific
+         * NMI, otherwise we may lose it, because the CPU-specific
+         * NMI can not be detected/processed on other CPUs.
+         */
+        if (notify_die(DIE_NMI, "nmi", regs, 0, 2, SIGINT) == NOTIFY_STOP)
+                return;
+
         cpu = smp_processor_id();
 
         /* Only the BSP gets external NMIs from the system. */
@@ -401,21 +409,10 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
                 reason = get_nmi_reason();
 
         if (!(reason & NMI_REASON_MASK)) {
-                if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
-                                                                == NOTIFY_STOP)
-                        return;
-
-#ifdef CONFIG_X86_LOCAL_APIC
-                if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT)
-                                                        == NOTIFY_STOP)
-                        return;
-#endif
                 unknown_nmi_error(reason, regs);
 
                 return;
         }
-        if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
-                return;
 
         /* AK: following checks seem to be broken on modern chipsets. FIXME */
         if (reason & NMI_REASON_SERR)
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 6e84ea42085a..e77ea0b566e0 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -65,7 +65,6 @@ static int profile_exceptions_notify(struct notifier_block *self,
 
         switch (val) {
         case DIE_NMI:
-        case DIE_NMI_IPI:
                 if (ctr_running)
                         model->check_ctrs(args->regs, &__get_cpu_var(cpu_msrs));
                 else if (!nmi_enabled)