diff options
| -rw-r--r-- | kernel/Makefile | 1 | ||||
| -rw-r--r-- | kernel/cpu/Makefile | 1 | ||||
| -rw-r--r-- | kernel/sched/Makefile | 2 | ||||
| -rw-r--r-- | kernel/sched/idle.c | 144 |
4 files changed, 145 insertions, 3 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index bc010ee..6f1c7e5 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -22,7 +22,6 @@ obj-y += sched/ obj-y += locking/ obj-y += power/ obj-y += printk/ -obj-y += cpu/ obj-y += irq/ obj-y += rcu/ diff --git a/kernel/cpu/Makefile b/kernel/cpu/Makefile deleted file mode 100644 index 59ab052..0000000 --- a/kernel/cpu/Makefile +++ /dev/null @@ -1 +0,0 @@ -obj-y = idle.o diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile index 9a95c8c..ab32b7b 100644 --- a/kernel/sched/Makefile +++ b/kernel/sched/Makefile @@ -13,7 +13,7 @@ endif obj-y += core.o proc.o clock.o cputime.o obj-y += idle_task.o fair.o rt.o deadline.o stop_task.o -obj-y += wait.o completion.o +obj-y += wait.o completion.o idle.o obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o obj-$(CONFIG_SCHEDSTATS) += stats.o diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c new file mode 100644 index 0000000..14ca434 --- /dev/null +++ b/kernel/sched/idle.c @@ -0,0 +1,144 @@ +/* + * Generic entry point for the idle threads + */ +#include <linux/sched.h> +#include <linux/cpu.h> +#include <linux/cpuidle.h> +#include <linux/tick.h> +#include <linux/mm.h> +#include <linux/stackprotector.h> + +#include <asm/tlb.h> + +#include <trace/events/power.h> + +static int __read_mostly cpu_idle_force_poll; + +void cpu_idle_poll_ctrl(bool enable) +{ + if (enable) { + cpu_idle_force_poll++; + } else { + cpu_idle_force_poll--; + WARN_ON_ONCE(cpu_idle_force_poll < 0); + } +} + +#ifdef CONFIG_GENERIC_IDLE_POLL_SETUP +static int __init cpu_idle_poll_setup(char *__unused) +{ + cpu_idle_force_poll = 1; + return 1; +} +__setup("nohlt", cpu_idle_poll_setup); + +static int __init cpu_idle_nopoll_setup(char *__unused) +{ + cpu_idle_force_poll = 0; + return 1; +} +__setup("hlt", cpu_idle_nopoll_setup); +#endif + +static inline int cpu_idle_poll(void) +{ + rcu_idle_enter(); + trace_cpu_idle_rcuidle(0, smp_processor_id()); + local_irq_enable(); + while (!tif_need_resched()) + cpu_relax(); + trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); + rcu_idle_exit(); + return 1; +} + +/* Weak implementations for optional arch specific functions */ +void __weak arch_cpu_idle_prepare(void) { } +void __weak arch_cpu_idle_enter(void) { } +void __weak arch_cpu_idle_exit(void) { } +void __weak arch_cpu_idle_dead(void) { } +void __weak arch_cpu_idle(void) +{ + cpu_idle_force_poll = 1; + local_irq_enable(); +} + +/* + * Generic idle loop implementation + */ +static void cpu_idle_loop(void) +{ + while (1) { + tick_nohz_idle_enter(); + + while (!need_resched()) { + check_pgt_cache(); + rmb(); + + if (cpu_is_offline(smp_processor_id())) + arch_cpu_idle_dead(); + + local_irq_disable(); + arch_cpu_idle_enter(); + + /* + * In poll mode we reenable interrupts and spin. + * + * Also if we detected in the wakeup from idle + * path that the tick broadcast device expired + * for us, we don't want to go deep idle as we + * know that the IPI is going to arrive right + * away + */ + if (cpu_idle_force_poll || tick_check_broadcast_expired()) { + cpu_idle_poll(); + } else { + if (!current_clr_polling_and_test()) { + stop_critical_timings(); + rcu_idle_enter(); + if (cpuidle_idle_call()) + arch_cpu_idle(); + if (WARN_ON_ONCE(irqs_disabled())) + local_irq_enable(); + rcu_idle_exit(); + start_critical_timings(); + } else { + local_irq_enable(); + } + __current_set_polling(); + } + arch_cpu_idle_exit(); + /* + * We need to test and propagate the TIF_NEED_RESCHED + * bit here because we might not have send the + * reschedule IPI to idle tasks. + */ + if (tif_need_resched()) + set_preempt_need_resched(); + } + tick_nohz_idle_exit(); + schedule_preempt_disabled(); + } +} + +void cpu_startup_entry(enum cpuhp_state state) +{ + /* + * This #ifdef needs to die, but it's too late in the cycle to + * make this generic (arm and sh have never invoked the canary + * init for the non boot cpus!). Will be fixed in 3.11 + */ +#ifdef CONFIG_X86 + /* + * If we're the non-boot CPU, nothing set the stack canary up + * for us. The boot CPU 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(); +#endif + __current_set_polling(); + arch_cpu_idle_prepare(); + cpu_idle_loop(); +} |