diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/mwait.h | 40 | ||||
| -rw-r--r-- | arch/x86/include/asm/processor.h | 23 | ||||
| -rw-r--r-- | arch/x86/kernel/acpi/cstate.c | 23 |
3 files changed, 40 insertions, 46 deletions
diff --git a/arch/x86/include/asm/mwait.h b/arch/x86/include/asm/mwait.h index 2f366d0ac6b4..361b02ef128c 100644 --- a/arch/x86/include/asm/mwait.h +++ b/arch/x86/include/asm/mwait.h @@ -1,6 +1,8 @@ #ifndef _ASM_X86_MWAIT_H #define _ASM_X86_MWAIT_H +#include <linux/sched.h> + #define MWAIT_SUBSTATE_MASK 0xf #define MWAIT_CSTATE_MASK 0xf #define MWAIT_SUBSTATE_SIZE 4 @@ -13,4 +15,42 @@ #define MWAIT_ECX_INTERRUPT_BREAK 0x1 +static inline void __monitor(const void *eax, unsigned long ecx, + unsigned long edx) +{ + /* "monitor %eax, %ecx, %edx;" */ + asm volatile(".byte 0x0f, 0x01, 0xc8;" + :: "a" (eax), "c" (ecx), "d"(edx)); +} + +static inline void __mwait(unsigned long eax, unsigned long ecx) +{ + /* "mwait %eax, %ecx;" */ + asm volatile(".byte 0x0f, 0x01, 0xc9;" + :: "a" (eax), "c" (ecx)); +} + +/* + * 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. + */ +static inline void mwait_idle_with_hints(unsigned long eax, unsigned long ecx) +{ + if (!current_set_polling_and_test()) { + if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR)) + clflush((void *)¤t_thread_info()->flags); + + __monitor((void *)¤t_thread_info()->flags, 0, 0); + if (!need_resched()) + __mwait(eax, ecx); + } + __current_clr_polling(); +} + #endif /* _ASM_X86_MWAIT_H */ diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 7b034a4057f9..24821f5768bc 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -700,29 +700,6 @@ static inline void sync_core(void) #endif } -static inline void __monitor(const void *eax, unsigned long ecx, - unsigned long edx) -{ - /* "monitor %eax, %ecx, %edx;" */ - asm volatile(".byte 0x0f, 0x01, 0xc8;" - :: "a" (eax), "c" (ecx), "d"(edx)); -} - -static inline void __mwait(unsigned long eax, unsigned long ecx) -{ - /* "mwait %eax, %ecx;" */ - asm volatile(".byte 0x0f, 0x01, 0xc9;" - :: "a" (eax), "c" (ecx)); -} - -static inline void __sti_mwait(unsigned long eax, unsigned long ecx) -{ - trace_hardirqs_on(); - /* "mwait %eax, %ecx;" */ - asm volatile("sti; .byte 0x0f, 0x01, 0xc9;" - :: "a" (eax), "c" (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 d2b7f27781bc..e69182fd01cf 100644 --- a/arch/x86/kernel/acpi/cstate.c +++ b/arch/x86/kernel/acpi/cstate.c @@ -150,29 +150,6 @@ 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(); |