x86: nmi_watchdog - use NMI_NONE by default

There is no need to keep NMI_DISABLED definition and use it
for nmi_watchdog by default. Here is the point why:

- IO-APIC and APIC chips are programmed for nmi_watchdog support at very
  early stage of kernel booting and not having nmi_watchdog specified as
  boot option lead only to nmi_watchdog becomes to NMI_NONE anyway
- enable nmi_watchdog thru /proc/sys/kernel/nmi if it was not specified at
  boot is not possible too (even having this sysfs entry)

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: macro@linux-mips.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 23 deletions

diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 427c511e7adc..32acda25e3cb 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -52,7 +52,7 @@ static cpumask_t backtrace_mask = CPU_MASK_NONE;
 atomic_t nmi_active = ATOMIC_INIT(0);           /* oprofile uses this */
 EXPORT_SYMBOL(nmi_active);
 
-unsigned int nmi_watchdog = NMI_DEFAULT;
+unsigned int nmi_watchdog = NMI_NONE;
 EXPORT_SYMBOL(nmi_watchdog);
 
 static int panic_on_timeout;
@@ -92,14 +92,6 @@ static inline unsigned int get_timer_irqs(int cpu)
 #endif
 }
 
-/* Run after command line and cpu_init init, but before all other checks */
-void nmi_watchdog_default(void)
-{
-        if (nmi_watchdog != NMI_DEFAULT)
-                return;
-        nmi_watchdog = NMI_NONE;
-}
-
 #ifdef CONFIG_SMP
 /*
  * The performance counters used by NMI_LOCAL_APIC don't trigger when
@@ -127,7 +119,7 @@ int __init check_nmi_watchdog(void)
         unsigned int *prev_nmi_count;
         int cpu;
 
-        if (nmi_watchdog == NMI_NONE || nmi_watchdog == NMI_DISABLED)
+        if (nmi_watchdog == NMI_NONE)
                 return 0;
 
         if (!atomic_read(&nmi_active))
@@ -482,24 +474,12 @@ int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file,
         if (!!old_state == !!nmi_watchdog_enabled)
                 return 0;
 
-        if (atomic_read(&nmi_active) < 0 || nmi_watchdog == NMI_DISABLED) {
+        if (atomic_read(&nmi_active) < 0 || nmi_watchdog == NMI_NONE) {
                 printk(KERN_WARNING
                         "NMI watchdog is permanently disabled\n");
                 return -EIO;
         }
 
-        /* if nmi_watchdog is not set yet, then set it */
-        nmi_watchdog_default();
-
-#ifdef CONFIG_X86_32
-        if (nmi_watchdog == NMI_NONE) {
-                if (lapic_watchdog_ok())
-                        nmi_watchdog = NMI_LOCAL_APIC;
-                else
-                        nmi_watchdog = NMI_IO_APIC;
-        }
-#endif
-
         if (nmi_watchdog == NMI_LOCAL_APIC) {
                 if (nmi_watchdog_enabled)
                         enable_lapic_nmi_watchdog();