#include <linux/user-return-notifier.h>
#include <linux/dmi.h>
#include <linux/utsname.h>
+#include <linux/stackprotector.h>
+#include <linux/tick.h>
+#include <linux/cpuidle.h>
#include <trace/events/power.h>
#include <linux/hw_breakpoint.h>
#include <asm/cpu.h>
-#include <asm/system.h>
#include <asm/apic.h>
#include <asm/syscalls.h>
#include <asm/idle.h>
#include <asm/uaccess.h>
#include <asm/i387.h>
+#include <asm/fpu-internal.h>
#include <asm/debugreg.h>
+#include <asm/nmi.h>
+
+#ifdef CONFIG_X86_64
+static DEFINE_PER_CPU(unsigned char, is_idle);
+static ATOMIC_NOTIFIER_HEAD(idle_notifier);
+
+void idle_notifier_register(struct notifier_block *n)
+{
+ atomic_notifier_chain_register(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_register);
+
+void idle_notifier_unregister(struct notifier_block *n)
+{
+ atomic_notifier_chain_unregister(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_unregister);
+#endif
struct kmem_cache *task_xstate_cachep;
EXPORT_SYMBOL_GPL(task_xstate_cachep);
EXPORT_SYMBOL(pm_idle);
#endif
-#ifdef CONFIG_X86_32
-/*
- * This halt magic was a workaround for ancient floppy DMA
- * wreckage. It should be safe to remove.
- */
-static int hlt_counter;
-void disable_hlt(void)
+static inline int hlt_use_halt(void)
{
- hlt_counter++;
+ return 1;
}
-EXPORT_SYMBOL(disable_hlt);
-void enable_hlt(void)
+#ifndef CONFIG_SMP
+static inline void play_dead(void)
{
- hlt_counter--;
+ BUG();
}
-EXPORT_SYMBOL(enable_hlt);
+#endif
-static inline int hlt_use_halt(void)
+#ifdef CONFIG_X86_64
+void enter_idle(void)
{
- return (!hlt_counter && boot_cpu_data.hlt_works_ok);
+ percpu_write(is_idle, 1);
+ atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
}
-#else
-static inline int hlt_use_halt(void)
+
+static void __exit_idle(void)
{
- return 1;
+ if (x86_test_and_clear_bit_percpu(0, is_idle) == 0)
+ return;
+ atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
+}
+
+/* Called from interrupts to signify idle end */
+void exit_idle(void)
+{
+ /* idle loop has pid 0 */
+ if (current->pid)
+ return;
+ __exit_idle();
}
#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)
+{
+ /*
+ * If we're the non-boot CPU, nothing set the stack canary up
+ * for us. CPU0 already has it initialized but no harm in
+ * doing it again. This is a good place for updating it, as
+ * we wont ever return from this function (so the invalid
+ * 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();
+
+ rcu_idle_exit();
+ start_critical_timings();
+
+ /* 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();
+ }
+
+ tick_nohz_idle_exit();
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
+}
+
/*
* We use this if we don't have any better
* idle routine..
void default_idle(void)
{
if (hlt_use_halt()) {
- trace_power_start(POWER_CSTATE, 1, smp_processor_id());
- trace_cpu_idle(1, smp_processor_id());
+ 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
else
local_irq_enable();
current_thread_info()->status |= TS_POLLING;
- trace_power_end(smp_processor_id());
- trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+ trace_power_end_rcuidle(smp_processor_id());
+ trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
} else {
local_irq_enable();
/* loop is done by the caller */
static void mwait_idle(void)
{
if (!need_resched()) {
- trace_power_start(POWER_CSTATE, 1, smp_processor_id());
- trace_cpu_idle(1, smp_processor_id());
+ 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 *)¤t_thread_info()->flags);
__sti_mwait(0, 0);
else
local_irq_enable();
- trace_power_end(smp_processor_id());
- trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+ trace_power_end_rcuidle(smp_processor_id());
+ trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
} else
local_irq_enable();
}
*/
static void poll_idle(void)
{
- trace_power_start(POWER_CSTATE, 0, smp_processor_id());
- trace_cpu_idle(0, smp_processor_id());
+ 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(smp_processor_id());
- trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
+ trace_power_end_rcuidle(smp_processor_id());
+ trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}
/*
projects / deliverable / linux.git / blobdiff