From 6491bc0c616969f7ae1fcb30a8823c333e2944c7 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 3 Feb 2015 21:55:11 +0100 Subject: [PATCH] ACPI / cpuidle: Common callback routine for entering states Introduce a common ->enter callback routine for the ACPI cpuidle driver, acpi_idle_enter(), which helps to reduce code complexity, size and duplication and prevents theoretically possible failues that an incorrect routine may be run to enter the given idle state due to a firmware bug (eg. when _CST returns a different set of states for each processor). Signed-off-by: Rafael J. Wysocki --- drivers/acpi/processor_idle.c | 118 +++++++++++++--------------------- 1 file changed, 45 insertions(+), 73 deletions(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 58113a6fa1d3..c256bd7fbd78 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -737,74 +737,17 @@ static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr) !pr->flags.has_cst; } -/** - * acpi_idle_enter_simple - enters a CPU idle state without BM handling - * @dev: the target CPU - * @drv: cpuidle driver with cpuidle state information - * @index: the index of suggested state - */ -static int acpi_idle_enter_simple(struct cpuidle_device *dev, - struct cpuidle_driver *drv, int index) -{ - struct acpi_processor *pr; - struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); - - pr = __this_cpu_read(processors); - - if (unlikely(!pr)) - return -EINVAL; - - if (cx->type != ACPI_STATE_C1 && acpi_idle_fallback_to_c1(pr)) { - index = CPUIDLE_DRIVER_STATE_START; - cx = per_cpu(acpi_cstate[index], dev->cpu); - } - - lapic_timer_state_broadcast(pr, cx, 1); - - if (cx->type == ACPI_STATE_C3) - ACPI_FLUSH_CPU_CACHE(); - - acpi_idle_do_entry(cx); - - lapic_timer_state_broadcast(pr, cx, 0); - return index; -} - static int c3_cpu_count; static DEFINE_RAW_SPINLOCK(c3_lock); /** * acpi_idle_enter_bm - enters C3 with proper BM handling - * @dev: the target CPU - * @drv: cpuidle driver containing state data - * @index: the index of suggested state - * - * If BM is detected, the deepest non-C3 idle state is entered instead. + * @pr: Target processor + * @cx: Target state context */ -static int acpi_idle_enter_bm(struct cpuidle_device *dev, - struct cpuidle_driver *drv, int index) +static void acpi_idle_enter_bm(struct acpi_processor *pr, + struct acpi_processor_cx *cx) { - struct acpi_processor *pr; - struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); - - pr = __this_cpu_read(processors); - - if (unlikely(!pr)) - return -EINVAL; - - if (acpi_idle_fallback_to_c1(pr)) - return acpi_idle_enter_simple(dev, drv, CPUIDLE_DRIVER_STATE_START); - - if (!cx->bm_sts_skip && acpi_idle_bm_check()) { - if (drv->safe_state_index >= 0) { - return drv->states[drv->safe_state_index].enter(dev, - drv, drv->safe_state_index); - } else { - acpi_safe_halt(); - return -EBUSY; - } - } - acpi_unlazy_tlb(smp_processor_id()); /* @@ -842,6 +785,45 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, } lapic_timer_state_broadcast(pr, cx, 0); +} + +static int acpi_idle_enter(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); + struct acpi_processor *pr; + + pr = __this_cpu_read(processors); + if (unlikely(!pr)) + return -EINVAL; + + if (cx->type != ACPI_STATE_C1) { + if (acpi_idle_fallback_to_c1(pr)) { + 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); + return index; + } else if (drv->safe_state_index >= 0) { + index = drv->safe_state_index; + cx = per_cpu(acpi_cstate[index], dev->cpu); + } else { + acpi_safe_halt(); + return -EBUSY; + } + } + } + + lapic_timer_state_broadcast(pr, cx, 1); + + if (cx->type == ACPI_STATE_C3) + ACPI_FLUSH_CPU_CACHE(); + + acpi_idle_do_entry(cx); + + lapic_timer_state_broadcast(pr, cx, 0); + return index; } @@ -936,22 +918,12 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); state->exit_latency = cx->latency; state->target_residency = cx->latency * latency_factor; + state->enter = acpi_idle_enter; state->flags = 0; - switch (cx->type) { - - case ACPI_STATE_C1: - case ACPI_STATE_C2: - state->enter = acpi_idle_enter_simple; + if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) { state->enter_dead = acpi_idle_play_dead; drv->safe_state_index = count; - break; - - case ACPI_STATE_C3: - state->enter = pr->flags.bm_check ? - acpi_idle_enter_bm : - acpi_idle_enter_simple; - break; } count++; -- 2.20.1