diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/processor.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/acpi/cstate.c | 23 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 23 |
3 files changed, 23 insertions, 25 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 219371546afd..0d1171c97729 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -751,8 +751,6 @@ static inline void __sti_mwait(unsigned long eax, unsigned long ecx) :: "a" (eax), "c" (ecx)); } -extern void mwait_idle_with_hints(unsigned long eax, unsigned long ecx); - extern void select_idle_routine(const struct cpuinfo_x86 *c); extern void init_amd_e400_c1e_mask(void); diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c index 5812404a0d4c..f50e7fb2a201 100644 --- a/arch/x86/kernel/acpi/cstate.c +++ b/arch/x86/kernel/acpi/cstate.c @@ -149,6 +149,29 @@ int acpi_processor_ffh_cstate_probe(unsigned int cpu, } EXPORT_SYMBOL_GPL(acpi_processor_ffh_cstate_probe); +/* + * This uses new MONITOR/MWAIT instructions on P4 processors with PNI, + * which can obviate IPI to trigger checking of need_resched. + * We execute MONITOR against need_resched and enter optimized wait state + * through MWAIT. Whenever someone changes need_resched, we would be woken + * up from MWAIT (without an IPI). + * + * New with Core Duo processors, MWAIT can take some hints based on CPU + * capability. + */ +void mwait_idle_with_hints(unsigned long ax, unsigned long cx) +{ + if (!need_resched()) { + if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR)) + clflush((void *)¤t_thread_info()->flags); + + __monitor((void *)¤t_thread_info()->flags, 0, 0); + smp_mb(); + if (!need_resched()) + __mwait(ax, cx); + } +} + void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx *cx) { unsigned int cpu = smp_processor_id(); diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index e1ba8cb24e4e..e7e3b019c439 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -438,29 +438,6 @@ void cpu_idle_wait(void) } EXPORT_SYMBOL_GPL(cpu_idle_wait); -/* - * This uses new MONITOR/MWAIT instructions on P4 processors with PNI, - * which can obviate IPI to trigger checking of need_resched. - * We execute MONITOR against need_resched and enter optimized wait state - * through MWAIT. Whenever someone changes need_resched, we would be woken - * up from MWAIT (without an IPI). - * - * New with Core Duo processors, MWAIT can take some hints based on CPU - * capability. - */ -void mwait_idle_with_hints(unsigned long ax, unsigned long cx) -{ - if (!need_resched()) { - if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR)) - clflush((void *)¤t_thread_info()->flags); - - __monitor((void *)¤t_thread_info()->flags, 0, 0); - smp_mb(); - if (!need_resched()) - __mwait(ax, cx); - } -} - /* Default MONITOR/MWAIT with no hints, used for default C1 state */ static void mwait_idle(void) { |