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ACPI / idle: Implement ->enter_freeze callback routine

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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 <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
This commit is contained in:
Rafael J. Wysocki 2015-02-11 05:04:57 +01:00 committed by Rafael J. Wysocki
parent 5fe2e52720
commit 5f50818520
1 changed files with 40 additions and 8 deletions
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48
drivers/acpi/processor_idle.c
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@ -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)