From 5f5081852038d9a7b309190730bfb724b413235e Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 11 Feb 2015 05:04:57 +0100 Subject: [PATCH] ACPI / idle: Implement ->enter_freeze callback routine Add an ->enter_freeze callback routine, acpi_idle_enter_freeze(), to the ACPI cpuidle driver and point ->enter_freeze to it for all the C2-type and C3-type states that don't need to fall back to C1 (which may be halt-induced and that will re-enable interrupts on exit from idle, which ->enter_freeze cannot do). Signed-off-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel) --- drivers/acpi/processor_idle.c | 48 +++++++++++++++++++++++++++++------ 1 file changed, 40 insertions(+), 8 deletions(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index c256bd7fbd78..c6bb9f1257c9 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -732,9 +732,8 @@ static int acpi_idle_play_dead(struct cpuidle_device *dev, int index) static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) { - return IS_ENABLED(CONFIG_HOTPLUG_CPU) && num_online_cpus() > 1 && - !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED) && - !pr->flags.has_cst; + return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst && + !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED); } static int c3_cpu_count; @@ -744,9 +743,10 @@ static DEFINE_RAW_SPINLOCK(c3_lock); * acpi_idle_enter_bm - enters C3 with proper BM handling * @pr: Target processor * @cx: Target state context + * @timer_bc: Whether or not to change timer mode to broadcast */ static void acpi_idle_enter_bm(struct acpi_processor *pr, - struct acpi_processor_cx *cx) + struct acpi_processor_cx *cx, bool timer_bc) { acpi_unlazy_tlb(smp_processor_id()); @@ -754,7 +754,8 @@ static void acpi_idle_enter_bm(struct acpi_processor *pr, * Must be done before busmaster disable as we might need to * access HPET ! */ - lapic_timer_state_broadcast(pr, cx, 1); + if (timer_bc) + lapic_timer_state_broadcast(pr, cx, 1); /* * disable bus master @@ -784,7 +785,8 @@ static void acpi_idle_enter_bm(struct acpi_processor *pr, raw_spin_unlock(&c3_lock); } - lapic_timer_state_broadcast(pr, cx, 0); + if (timer_bc) + lapic_timer_state_broadcast(pr, cx, 0); } static int acpi_idle_enter(struct cpuidle_device *dev, @@ -798,12 +800,12 @@ static int acpi_idle_enter(struct cpuidle_device *dev, return -EINVAL; if (cx->type != ACPI_STATE_C1) { - if (acpi_idle_fallback_to_c1(pr)) { + if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { index = CPUIDLE_DRIVER_STATE_START; cx = per_cpu(acpi_cstate[index], dev->cpu); } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) { if (cx->bm_sts_skip || !acpi_idle_bm_check()) { - acpi_idle_enter_bm(pr, cx); + acpi_idle_enter_bm(pr, cx, true); return index; } else if (drv->safe_state_index >= 0) { index = drv->safe_state_index; @@ -827,6 +829,27 @@ static int acpi_idle_enter(struct cpuidle_device *dev, return index; } +static void acpi_idle_enter_freeze(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); + + if (cx->type == ACPI_STATE_C3) { + struct acpi_processor *pr = __this_cpu_read(processors); + + if (unlikely(!pr)) + return; + + if (pr->flags.bm_check) { + acpi_idle_enter_bm(pr, cx, false); + return; + } else { + ACPI_FLUSH_CPU_CACHE(); + } + } + acpi_idle_do_entry(cx); +} + struct cpuidle_driver acpi_idle_driver = { .name = "acpi_idle", .owner = THIS_MODULE, @@ -925,6 +948,15 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) state->enter_dead = acpi_idle_play_dead; drv->safe_state_index = count; } + /* + * Halt-induced C1 is not good for ->enter_freeze, because it + * re-enables interrupts on exit. Moreover, C1 is generally not + * particularly interesting from the suspend-to-idle angle, so + * avoid C1 and the situations in which we may need to fall back + * to it altogether. + */ + if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr)) + state->enter_freeze = acpi_idle_enter_freeze; count++; if (count == CPUIDLE_STATE_MAX) -- 2.34.1