diff options
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 116 |
1 files changed, 17 insertions, 99 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index dcfc1f410dc4..14ae10031ff0 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -268,13 +268,7 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE; EXPORT_SYMBOL(boot_option_idle_override); -/* - * Powermanagement idle function, if any.. - */ -void (*pm_idle)(void); -#ifdef CONFIG_APM_MODULE -EXPORT_SYMBOL(pm_idle); -#endif +static void (*x86_idle)(void); #ifndef CONFIG_SMP static inline void play_dead(void) @@ -351,7 +345,7 @@ void cpu_idle(void) rcu_idle_enter(); if (cpuidle_idle_call()) - pm_idle(); + x86_idle(); rcu_idle_exit(); start_critical_timings(); @@ -394,14 +388,16 @@ void default_idle(void) EXPORT_SYMBOL(default_idle); #endif -bool set_pm_idle_to_default(void) +#ifdef CONFIG_XEN +bool xen_set_default_idle(void) { - bool ret = !!pm_idle; + bool ret = !!x86_idle; - pm_idle = default_idle; + x86_idle = default_idle; return ret; } +#endif void stop_this_cpu(void *dummy) { local_irq_disable(); @@ -411,29 +407,8 @@ void stop_this_cpu(void *dummy) set_cpu_online(smp_processor_id(), false); disable_local_APIC(); - for (;;) { - if (hlt_works(smp_processor_id())) - halt(); - } -} - -/* Default MONITOR/MWAIT with no hints, used for default C1 state */ -static void mwait_idle(void) -{ - if (!need_resched()) { - trace_cpu_idle_rcuidle(1, smp_processor_id()); - 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()) - __sti_mwait(0, 0); - else - local_irq_enable(); - trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); - } else - local_irq_enable(); + for (;;) + halt(); } /* @@ -450,53 +425,6 @@ static void poll_idle(void) trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); } -/* - * mwait selection logic: - * - * It depends on the CPU. For AMD CPUs that support MWAIT this is - * wrong. Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings - * then depend on a clock divisor and current Pstate of the core. If - * all cores of a processor are in halt state (C1) the processor can - * enter the C1E (C1 enhanced) state. If mwait is used this will never - * happen. - * - * idle=mwait overrides this decision and forces the usage of mwait. - */ - -#define MWAIT_INFO 0x05 -#define MWAIT_ECX_EXTENDED_INFO 0x01 -#define MWAIT_EDX_C1 0xf0 - -int mwait_usable(const struct cpuinfo_x86 *c) -{ - u32 eax, ebx, ecx, edx; - - /* Use mwait if idle=mwait boot option is given */ - if (boot_option_idle_override == IDLE_FORCE_MWAIT) - return 1; - - /* - * Any idle= boot option other than idle=mwait means that we must not - * use mwait. Eg: idle=halt or idle=poll or idle=nomwait - */ - if (boot_option_idle_override != IDLE_NO_OVERRIDE) - return 0; - - if (c->cpuid_level < MWAIT_INFO) - return 0; - - cpuid(MWAIT_INFO, &eax, &ebx, &ecx, &edx); - /* Check, whether EDX has extended info about MWAIT */ - if (!(ecx & MWAIT_ECX_EXTENDED_INFO)) - return 1; - - /* - * edx enumeratios MONITOR/MWAIT extensions. Check, whether - * C1 supports MWAIT - */ - return (edx & MWAIT_EDX_C1); -} - bool amd_e400_c1e_detected; EXPORT_SYMBOL(amd_e400_c1e_detected); @@ -561,31 +489,24 @@ static void amd_e400_idle(void) void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) { #ifdef CONFIG_SMP - if (pm_idle == poll_idle && smp_num_siblings > 1) { + if (x86_idle == poll_idle && smp_num_siblings > 1) pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n"); - } #endif - if (pm_idle) + if (x86_idle) return; - if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) { - /* - * One CPU supports mwait => All CPUs supports mwait - */ - pr_info("using mwait in idle threads\n"); - pm_idle = mwait_idle; - } else if (cpu_has_amd_erratum(amd_erratum_400)) { + if (cpu_has_amd_erratum(amd_erratum_400)) { /* E400: APIC timer interrupt does not wake up CPU from C1e */ pr_info("using AMD E400 aware idle routine\n"); - pm_idle = amd_e400_idle; + x86_idle = amd_e400_idle; } else - pm_idle = default_idle; + x86_idle = default_idle; } void __init init_amd_e400_c1e_mask(void) { /* If we're using amd_e400_idle, we need to allocate amd_e400_c1e_mask. */ - if (pm_idle == amd_e400_idle) + if (x86_idle == amd_e400_idle) zalloc_cpumask_var(&amd_e400_c1e_mask, GFP_KERNEL); } @@ -596,11 +517,8 @@ static int __init idle_setup(char *str) if (!strcmp(str, "poll")) { pr_info("using polling idle threads\n"); - pm_idle = poll_idle; + x86_idle = poll_idle; boot_option_idle_override = IDLE_POLL; - } else if (!strcmp(str, "mwait")) { - boot_option_idle_override = IDLE_FORCE_MWAIT; - WARN_ONCE(1, "\"idle=mwait\" will be removed in 2012\n"); } else if (!strcmp(str, "halt")) { /* * When the boot option of idle=halt is added, halt is @@ -609,7 +527,7 @@ static int __init idle_setup(char *str) * To continue to load the CPU idle driver, don't touch * the boot_option_idle_override. */ - pm_idle = default_idle; + x86_idle = default_idle; boot_option_idle_override = IDLE_HALT; } else if (!strcmp(str, "nomwait")) { /* |