Fix potential fast PIT TSC calibration startup glitch

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / process.c

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index cff9a50e389db8a87b60bca54824dc833cbb1f39..6d12f7e37f8c1da5a465b110ff75ecae8c01f0c8 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -1,6 +1,7 @@
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <asm/idle.h>
 #include <linux/smp.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
@@ -9,6 +10,7 @@
 #include <linux/clockchips.h>
 #include <linux/ftrace.h>
 #include <asm/system.h>
+#include <asm/apic.h>
 
 unsigned long idle_halt;
 EXPORT_SYMBOL(idle_halt);
@@ -127,6 +129,21 @@ void default_idle(void)
 EXPORT_SYMBOL(default_idle);
 #endif
 
+void stop_this_cpu(void *dummy)
+{
+       local_irq_disable();
+       /*
+        * Remove this CPU:
+        */
+       cpu_clear(smp_processor_id(), cpu_online_map);
+       disable_local_APIC();
+
+       for (;;) {
+               if (hlt_works(smp_processor_id()))
+                       halt();
+       }
+}
+
 static void do_nothing(void *unused)
 {
 }
@@ -163,6 +180,9 @@ void mwait_idle_with_hints(unsigned long ax, unsigned long cx)
 
        trace_power_start(&it, POWER_CSTATE, (ax>>4)+1);
        if (!need_resched()) {
+               if (cpu_has(&current_cpu_data, X86_FEATURE_CLFLUSH_MONITOR))
+                       clflush((void *)&current_thread_info()->flags);
+
                __monitor((void *)&current_thread_info()->flags, 0, 0);
                smp_mb();
                if (!need_resched())
@@ -177,6 +197,9 @@ static void mwait_idle(void)
        struct power_trace it;
        if (!need_resched()) {
                trace_power_start(&it, POWER_CSTATE, 1);
+               if (cpu_has(&current_cpu_data, X86_FEATURE_CLFLUSH_MONITOR))
+                       clflush((void *)&current_thread_info()->flags);
+
                __monitor((void *)&current_thread_info()->flags, 0, 0);
                smp_mb();
                if (!need_resched())