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Diffstat (limited to 'arch/x86/kernel/process.c')
-rw-r--r--arch/x86/kernel/process.c243
1 files changed, 40 insertions, 203 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 2ed787f15bf..607af0d4d5e 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -121,30 +121,6 @@ void exit_thread(void)
drop_fpu(me);
}
-void show_regs_common(void)
-{
- const char *vendor, *product, *board;
-
- vendor = dmi_get_system_info(DMI_SYS_VENDOR);
- if (!vendor)
- vendor = "";
- product = dmi_get_system_info(DMI_PRODUCT_NAME);
- if (!product)
- product = "";
-
- /* Board Name is optional */
- board = dmi_get_system_info(DMI_BOARD_NAME);
-
- printk(KERN_DEFAULT "Pid: %d, comm: %.20s %s %s %.*s %s %s%s%s\n",
- current->pid, current->comm, print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version,
- vendor, product,
- board ? "/" : "",
- board ? board : "");
-}
-
void flush_thread(void)
{
struct task_struct *tsk = current;
@@ -268,13 +244,7 @@ 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)
@@ -307,13 +277,7 @@ void exit_idle(void)
}
#endif
-/*
- * The idle thread. There's no useful work to be
- * done, so just try to conserve power and have a
- * low exit latency (ie sit in a loop waiting for
- * somebody to say that they'd like to reschedule)
- */
-void cpu_idle(void)
+void arch_cpu_idle_prepare(void)
{
/*
* If we're the non-boot CPU, nothing set the stack canary up
@@ -323,87 +287,56 @@ void cpu_idle(void)
* canaries already on the stack wont ever trigger).
*/
boot_init_stack_canary();
- current_thread_info()->status |= TS_POLLING;
-
- while (1) {
- tick_nohz_idle_enter();
-
- while (!need_resched()) {
- rmb();
-
- if (cpu_is_offline(smp_processor_id()))
- play_dead();
-
- /*
- * Idle routines should keep interrupts disabled
- * from here on, until they go to idle.
- * Otherwise, idle callbacks can misfire.
- */
- local_touch_nmi();
- local_irq_disable();
-
- enter_idle();
-
- /* Don't trace irqs off for idle */
- stop_critical_timings();
-
- /* enter_idle() needs rcu for notifiers */
- rcu_idle_enter();
+}
- if (cpuidle_idle_call())
- pm_idle();
+void arch_cpu_idle_enter(void)
+{
+ local_touch_nmi();
+ enter_idle();
+}
- rcu_idle_exit();
- start_critical_timings();
+void arch_cpu_idle_exit(void)
+{
+ __exit_idle();
+}
- /* In many cases the interrupt that ended idle
- has already called exit_idle. But some idle
- loops can be woken up without interrupt. */
- __exit_idle();
- }
+void arch_cpu_idle_dead(void)
+{
+ play_dead();
+}
- tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
- }
+/*
+ * Called from the generic idle code.
+ */
+void arch_cpu_idle(void)
+{
+ if (cpuidle_idle_call())
+ x86_idle();
}
/*
- * We use this if we don't have any better
- * idle routine..
+ * We use this if we don't have any better idle routine..
*/
void default_idle(void)
{
- trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id());
trace_cpu_idle_rcuidle(1, smp_processor_id());
- current_thread_info()->status &= ~TS_POLLING;
- /*
- * TS_POLLING-cleared state must be visible before we
- * test NEED_RESCHED:
- */
- smp_mb();
-
- if (!need_resched())
- safe_halt(); /* enables interrupts racelessly */
- else
- local_irq_enable();
- current_thread_info()->status |= TS_POLLING;
- trace_power_end_rcuidle(smp_processor_id());
+ safe_halt();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}
#ifdef CONFIG_APM_MODULE
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();
@@ -413,94 +346,8 @@ 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_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id());
- trace_cpu_idle_rcuidle(1, smp_processor_id());
- if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR))
- clflush((void *)&current_thread_info()->flags);
-
- __monitor((void *)&current_thread_info()->flags, 0, 0);
- smp_mb();
- if (!need_resched())
- __sti_mwait(0, 0);
- else
- local_irq_enable();
- trace_power_end_rcuidle(smp_processor_id());
- trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
- } else
- local_irq_enable();
-}
-
-/*
- * On SMP it's slightly faster (but much more power-consuming!)
- * to poll the ->work.need_resched flag instead of waiting for the
- * cross-CPU IPI to arrive. Use this option with caution.
- */
-static void poll_idle(void)
-{
- trace_power_start_rcuidle(POWER_CSTATE, 0, smp_processor_id());
- trace_cpu_idle_rcuidle(0, smp_processor_id());
- local_irq_enable();
- while (!need_resched())
- cpu_relax();
- trace_power_end_rcuidle(smp_processor_id());
- 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);
+ for (;;)
+ halt();
}
bool amd_e400_c1e_detected;
@@ -567,31 +414,24 @@ 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 (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1)
pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n");
- }
#endif
- if (pm_idle)
+ if (x86_idle || boot_option_idle_override == IDLE_POLL)
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_bug(c, X86_BUG_AMD_APIC_C1E)) {
/* 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);
}
@@ -602,11 +442,8 @@ static int __init idle_setup(char *str)
if (!strcmp(str, "poll")) {
pr_info("using polling idle threads\n");
- pm_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");
+ cpu_idle_poll_ctrl(true);
} else if (!strcmp(str, "halt")) {
/*
* When the boot option of idle=halt is added, halt is
@@ -615,7 +452,7 @@ 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")) {
/*
generated by cgit v1.2.3-70-g09d2 (git 2.51.2) at 2025-11-08 03:11:34 +0000