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Merge branch 'acpi-processor'
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* acpi-processor:
  ACPI / cpuidle: Common callback routine for entering states
  ACPI / cpuidle: Merge acpi_idle_enter_c1() and acpi_idle_enter_simple()
  ACPI / cpuidle: Drop flags.bm_check tests from acpi_idle_enter_bm()
  ACPI / cpuidle: Clean up white space in a switch statement
  ACPI / cpuidle: Drop irrelevant comment from acpi_idle_enter_simple()
  ACPI / cpuidle: Clean up fallback to C1 checks
  ACPI / cpuidle: Drop unnecessary calls from ->enter callback routines
  ACPI / cpuidle: Drop unnecessary calls from acpi_idle_do_entry()
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Rafael J. Wysocki committed Feb 10, 2015
2 parents ca45c87 + 6491bc0 commit d232096
Showing 1 changed file with 52 additions and 130 deletions.
182 changes: 52 additions & 130 deletions drivers/acpi/processor_idle.c
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Original file line number Diff line number Diff line change
Expand Up @@ -681,15 +681,13 @@ static int acpi_idle_bm_check(void)
}

/**
* acpi_idle_do_entry - a helper function that does C2 and C3 type entry
* acpi_idle_do_entry - enter idle state using the appropriate method
* @cx: cstate data
*
* Caller disables interrupt before call and enables interrupt after return.
*/
static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
static void acpi_idle_do_entry(struct acpi_processor_cx *cx)
{
/* Don't trace irqs off for idle */
stop_critical_timings();
if (cx->entry_method == ACPI_CSTATE_FFH) {
/* Call into architectural FFH based C-state */
acpi_processor_ffh_cstate_enter(cx);
Expand All @@ -703,37 +701,8 @@ static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
gets asserted in time to freeze execution properly. */
inl(acpi_gbl_FADT.xpm_timer_block.address);
}
start_critical_timings();
}

/**
* acpi_idle_enter_c1 - enters an ACPI C1 state-type
* @dev: the target CPU
* @drv: cpuidle driver containing cpuidle state info
* @index: index of target state
*
* This is equivalent to the HALT instruction.
*/
static int acpi_idle_enter_c1(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;

lapic_timer_state_broadcast(pr, cx, 1);
acpi_idle_do_entry(cx);

lapic_timer_state_broadcast(pr, cx, 0);

return index;
}


/**
* acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
* @dev: the target CPU
Expand Down Expand Up @@ -761,92 +730,26 @@ static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
return 0;
}

/**
* acpi_idle_enter_simple - enters an ACPI 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)
static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
{
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;

#ifdef CONFIG_HOTPLUG_CPU
if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
!pr->flags.has_cst &&
!(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
return acpi_idle_enter_c1(dev, drv, CPUIDLE_DRIVER_STATE_START);
#endif

/*
* Must be done before busmaster disable as we might need to
* access HPET !
*/
lapic_timer_state_broadcast(pr, cx, 1);

if (cx->type == ACPI_STATE_C3)
ACPI_FLUSH_CPU_CACHE();

/* Tell the scheduler that we are going deep-idle: */
sched_clock_idle_sleep_event();
acpi_idle_do_entry(cx);

sched_clock_idle_wakeup_event(0);

lapic_timer_state_broadcast(pr, cx, 0);
return index;
return IS_ENABLED(CONFIG_HOTPLUG_CPU) && num_online_cpus() > 1 &&
!(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED) &&
!pr->flags.has_cst;
}

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;

#ifdef CONFIG_HOTPLUG_CPU
if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
!pr->flags.has_cst &&
!(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
return acpi_idle_enter_c1(dev, drv, CPUIDLE_DRIVER_STATE_START);
#endif

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());

/* Tell the scheduler that we are going deep-idle: */
sched_clock_idle_sleep_event();
/*
* Must be done before busmaster disable as we might need to
* access HPET !
Expand All @@ -856,37 +759,71 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
/*
* disable bus master
* bm_check implies we need ARB_DIS
* !bm_check implies we need cache flush
* bm_control implies whether we can do ARB_DIS
*
* That leaves a case where bm_check is set and bm_control is
* not set. In that case we cannot do much, we enter C3
* without doing anything.
*/
if (pr->flags.bm_check && pr->flags.bm_control) {
if (pr->flags.bm_control) {
raw_spin_lock(&c3_lock);
c3_cpu_count++;
/* Disable bus master arbitration when all CPUs are in C3 */
if (c3_cpu_count == num_online_cpus())
acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
raw_spin_unlock(&c3_lock);
} else if (!pr->flags.bm_check) {
ACPI_FLUSH_CPU_CACHE();
}

acpi_idle_do_entry(cx);

/* Re-enable bus master arbitration */
if (pr->flags.bm_check && pr->flags.bm_control) {
if (pr->flags.bm_control) {
raw_spin_lock(&c3_lock);
acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
c3_cpu_count--;
raw_spin_unlock(&c3_lock);
}

sched_clock_idle_wakeup_event(0);
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;
}

Expand Down Expand Up @@ -981,27 +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:

state->enter = acpi_idle_enter_c1;
state->enter_dead = acpi_idle_play_dead;
drv->safe_state_index = count;
break;

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++;
Expand Down

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