#define ACPI_PROCESSOR_FILE_POWER "power"
#define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
#define PM_TIMER_TICK_NS (1000000000ULL/PM_TIMER_FREQUENCY)
-#ifndef CONFIG_CPU_IDLE
-#define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
-#define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
-static void (*pm_idle_save) (void) __read_mostly;
-#else
#define C2_OVERHEAD 1 /* 1us */
#define C3_OVERHEAD 1 /* 1us */
-#endif
#define PM_TIMER_TICKS_TO_US(p) (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
-#ifdef CONFIG_CPU_IDLE
module_param(max_cstate, uint, 0000);
-#else
-module_param(max_cstate, uint, 0644);
-#endif
static unsigned int nocst __read_mostly;
module_param(nocst, uint, 0000);
-#ifndef CONFIG_CPU_IDLE
-/*
- * bm_history -- bit-mask with a bit per jiffy of bus-master activity
- * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
- * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
- * 100 HZ: 0x0000000F: 4 jiffies = 40ms
- * reduce history for more aggressive entry into C3
- */
-static unsigned int bm_history __read_mostly =
- (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
-module_param(bm_history, uint, 0644);
-
-static int acpi_processor_set_power_policy(struct acpi_processor *pr);
-
-#else /* CONFIG_CPU_IDLE */
static unsigned int latency_factor __read_mostly = 2;
module_param(latency_factor, uint, 0644);
-#endif
/*
* IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
current_thread_info()->status |= TS_POLLING;
}
-#ifndef CONFIG_CPU_IDLE
-
-static void
-acpi_processor_power_activate(struct acpi_processor *pr,
- struct acpi_processor_cx *new)
-{
- struct acpi_processor_cx *old;
-
- if (!pr || !new)
- return;
-
- old = pr->power.state;
-
- if (old)
- old->promotion.count = 0;
- new->demotion.count = 0;
-
- pr->power.state = new;
-
- return;
-}
-
-static atomic_t c3_cpu_count;
-
-/* Common C-state entry for C2, C3, .. */
-static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
-{
- /* Don't trace irqs off for idle */
- stop_critical_timings();
- if (cstate->entry_method == ACPI_CSTATE_FFH) {
- /* Call into architectural FFH based C-state */
- acpi_processor_ffh_cstate_enter(cstate);
- } else {
- int unused;
- /* IO port based C-state */
- inb(cstate->address);
- /* Dummy wait op - must do something useless after P_LVL2 read
- because chipsets cannot guarantee that STPCLK# signal
- gets asserted in time to freeze execution properly. */
- unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
- }
- start_critical_timings();
-}
-#endif /* !CONFIG_CPU_IDLE */
-
#ifdef ARCH_APICTIMER_STOPS_ON_C3
/*
}
#endif
-#ifndef CONFIG_CPU_IDLE
-static void acpi_processor_idle(void)
-{
- struct acpi_processor *pr = NULL;
- struct acpi_processor_cx *cx = NULL;
- struct acpi_processor_cx *next_state = NULL;
- int sleep_ticks = 0;
- u32 t1, t2 = 0;
-
- /*
- * Interrupts must be disabled during bus mastering calculations and
- * for C2/C3 transitions.
- */
- local_irq_disable();
-
- pr = __get_cpu_var(processors);
- if (!pr) {
- local_irq_enable();
- return;
- }
-
- /*
- * Check whether we truly need to go idle, or should
- * reschedule:
- */
- if (unlikely(need_resched())) {
- local_irq_enable();
- return;
- }
-
- cx = pr->power.state;
- if (!cx || acpi_idle_suspend) {
- if (pm_idle_save) {
- pm_idle_save(); /* enables IRQs */
- } else {
- acpi_safe_halt();
- local_irq_enable();
- }
-
- return;
- }
-
- /*
- * Check BM Activity
- * -----------------
- * Check for bus mastering activity (if required), record, and check
- * for demotion.
- */
- if (pr->flags.bm_check) {
- u32 bm_status = 0;
- unsigned long diff = jiffies - pr->power.bm_check_timestamp;
-
- if (diff > 31)
- diff = 31;
-
- pr->power.bm_activity <<= diff;
-
- acpi_get_register_unlocked(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
- if (bm_status) {
- pr->power.bm_activity |= 0x1;
- acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
- }
- /*
- * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
- * the true state of bus mastering activity; forcing us to
- * manually check the BMIDEA bit of each IDE channel.
- */
- else if (errata.piix4.bmisx) {
- if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
- || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
- pr->power.bm_activity |= 0x1;
- }
-
- pr->power.bm_check_timestamp = jiffies;
-
- /*
- * If bus mastering is or was active this jiffy, demote
- * to avoid a faulty transition. Note that the processor
- * won't enter a low-power state during this call (to this
- * function) but should upon the next.
- *
- * TBD: A better policy might be to fallback to the demotion
- * state (use it for this quantum only) istead of
- * demoting -- and rely on duration as our sole demotion
- * qualification. This may, however, introduce DMA
- * issues (e.g. floppy DMA transfer overrun/underrun).
- */
- if ((pr->power.bm_activity & 0x1) &&
- cx->demotion.threshold.bm) {
- local_irq_enable();
- next_state = cx->demotion.state;
- goto end;
- }
- }
-
-#ifdef CONFIG_HOTPLUG_CPU
- /*
- * Check for P_LVL2_UP flag before entering C2 and above on
- * an SMP system. We do it here instead of doing it at _CST/P_LVL
- * detection phase, to work cleanly with logical CPU hotplug.
- */
- if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
- !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
- cx = &pr->power.states[ACPI_STATE_C1];
-#endif
-
- /*
- * Sleep:
- * ------
- * Invoke the current Cx state to put the processor to sleep.
- */
- if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
- current_thread_info()->status &= ~TS_POLLING;
- /*
- * TS_POLLING-cleared state must be visible before we
- * test NEED_RESCHED:
- */
- smp_mb();
- if (need_resched()) {
- current_thread_info()->status |= TS_POLLING;
- local_irq_enable();
- return;
- }
- }
-
- switch (cx->type) {
-
- case ACPI_STATE_C1:
- /*
- * Invoke C1.
- * Use the appropriate idle routine, the one that would
- * be used without acpi C-states.
- */
- if (pm_idle_save) {
- pm_idle_save(); /* enables IRQs */
- } else {
- acpi_safe_halt();
- local_irq_enable();
- }
-
- /*
- * TBD: Can't get time duration while in C1, as resumes
- * go to an ISR rather than here. Need to instrument
- * base interrupt handler.
- *
- * Note: the TSC better not stop in C1, sched_clock() will
- * skew otherwise.
- */
- sleep_ticks = 0xFFFFFFFF;
-
- break;
-
- case ACPI_STATE_C2:
- /* Get start time (ticks) */
- t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
- /* Tell the scheduler that we are going deep-idle: */
- sched_clock_idle_sleep_event();
- /* Invoke C2 */
- acpi_state_timer_broadcast(pr, cx, 1);
- acpi_cstate_enter(cx);
- /* Get end time (ticks) */
- t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
-
-#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
- /* TSC halts in C2, so notify users */
- if (tsc_halts_in_c(ACPI_STATE_C2))
- mark_tsc_unstable("possible TSC halt in C2");
-#endif
- /* Compute time (ticks) that we were actually asleep */
- sleep_ticks = ticks_elapsed(t1, t2);
-
- /* Tell the scheduler how much we idled: */
- sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
-
- /* Re-enable interrupts */
- local_irq_enable();
- /* Do not account our idle-switching overhead: */
- sleep_ticks -= cx->latency_ticks + C2_OVERHEAD;
-
- current_thread_info()->status |= TS_POLLING;
- acpi_state_timer_broadcast(pr, cx, 0);
- break;
-
- case ACPI_STATE_C3:
- acpi_unlazy_tlb(smp_processor_id());
- /*
- * Must be done before busmaster disable as we might
- * need to access HPET !
- */
- acpi_state_timer_broadcast(pr, cx, 1);
- /*
- * 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 (atomic_inc_return(&c3_cpu_count) ==
- num_online_cpus()) {
- /*
- * All CPUs are trying to go to C3
- * Disable bus master arbitration
- */
- acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
- }
- } else if (!pr->flags.bm_check) {
- /* SMP with no shared cache... Invalidate cache */
- ACPI_FLUSH_CPU_CACHE();
- }
-
- /* Get start time (ticks) */
- t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
- /* Invoke C3 */
- /* Tell the scheduler that we are going deep-idle: */
- sched_clock_idle_sleep_event();
- acpi_cstate_enter(cx);
- /* Get end time (ticks) */
- t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
- if (pr->flags.bm_check && pr->flags.bm_control) {
- /* Enable bus master arbitration */
- atomic_dec(&c3_cpu_count);
- acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
- }
-
-#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
- /* TSC halts in C3, so notify users */
- if (tsc_halts_in_c(ACPI_STATE_C3))
- mark_tsc_unstable("TSC halts in C3");
-#endif
- /* Compute time (ticks) that we were actually asleep */
- sleep_ticks = ticks_elapsed(t1, t2);
- /* Tell the scheduler how much we idled: */
- sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
-
- /* Re-enable interrupts */
- local_irq_enable();
- /* Do not account our idle-switching overhead: */
- sleep_ticks -= cx->latency_ticks + C3_OVERHEAD;
-
- current_thread_info()->status |= TS_POLLING;
- acpi_state_timer_broadcast(pr, cx, 0);
- break;
-
- default:
- local_irq_enable();
- return;
- }
- cx->usage++;
- if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
- cx->time += sleep_ticks;
-
- next_state = pr->power.state;
-
-#ifdef CONFIG_HOTPLUG_CPU
- /* Don't do promotion/demotion */
- if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
- !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) {
- next_state = cx;
- goto end;
- }
-#endif
-
- /*
- * Promotion?
- * ----------
- * Track the number of longs (time asleep is greater than threshold)
- * and promote when the count threshold is reached. Note that bus
- * mastering activity may prevent promotions.
- * Do not promote above max_cstate.
- */
- if (cx->promotion.state &&
- ((cx->promotion.state - pr->power.states) <= max_cstate)) {
- if (sleep_ticks > cx->promotion.threshold.ticks &&
- cx->promotion.state->latency <=
- pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) {
- cx->promotion.count++;
- cx->demotion.count = 0;
- if (cx->promotion.count >=
- cx->promotion.threshold.count) {
- if (pr->flags.bm_check) {
- if (!
- (pr->power.bm_activity & cx->
- promotion.threshold.bm)) {
- next_state =
- cx->promotion.state;
- goto end;
- }
- } else {
- next_state = cx->promotion.state;
- goto end;
- }
- }
- }
- }
-
- /*
- * Demotion?
- * ---------
- * Track the number of shorts (time asleep is less than time threshold)
- * and demote when the usage threshold is reached.
- */
- if (cx->demotion.state) {
- if (sleep_ticks < cx->demotion.threshold.ticks) {
- cx->demotion.count++;
- cx->promotion.count = 0;
- if (cx->demotion.count >= cx->demotion.threshold.count) {
- next_state = cx->demotion.state;
- goto end;
- }
- }
- }
-
- end:
- /*
- * Demote if current state exceeds max_cstate
- * or if the latency of the current state is unacceptable
- */
- if ((pr->power.state - pr->power.states) > max_cstate ||
- pr->power.state->latency >
- pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY)) {
- if (cx->demotion.state)
- next_state = cx->demotion.state;
- }
-
- /*
- * New Cx State?
- * -------------
- * If we're going to start using a new Cx state we must clean up
- * from the previous and prepare to use the new.
- */
- if (next_state != pr->power.state)
- acpi_processor_power_activate(pr, next_state);
-}
-
-static int acpi_processor_set_power_policy(struct acpi_processor *pr)
-{
- unsigned int i;
- unsigned int state_is_set = 0;
- struct acpi_processor_cx *lower = NULL;
- struct acpi_processor_cx *higher = NULL;
- struct acpi_processor_cx *cx;
-
-
- if (!pr)
- return -EINVAL;
-
- /*
- * This function sets the default Cx state policy (OS idle handler).
- * Our scheme is to promote quickly to C2 but more conservatively
- * to C3. We're favoring C2 for its characteristics of low latency
- * (quick response), good power savings, and ability to allow bus
- * mastering activity. Note that the Cx state policy is completely
- * customizable and can be altered dynamically.
- */
-
- /* startup state */
- for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
- cx = &pr->power.states[i];
- if (!cx->valid)
- continue;
-
- if (!state_is_set)
- pr->power.state = cx;
- state_is_set++;
- break;
- }
-
- if (!state_is_set)
- return -ENODEV;
-
- /* demotion */
- for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
- cx = &pr->power.states[i];
- if (!cx->valid)
- continue;
-
- if (lower) {
- cx->demotion.state = lower;
- cx->demotion.threshold.ticks = cx->latency_ticks;
- cx->demotion.threshold.count = 1;
- if (cx->type == ACPI_STATE_C3)
- cx->demotion.threshold.bm = bm_history;
- }
-
- lower = cx;
- }
-
- /* promotion */
- for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
- cx = &pr->power.states[i];
- if (!cx->valid)
- continue;
-
- if (higher) {
- cx->promotion.state = higher;
- cx->promotion.threshold.ticks = cx->latency_ticks;
- if (cx->type >= ACPI_STATE_C2)
- cx->promotion.threshold.count = 4;
- else
- cx->promotion.threshold.count = 10;
- if (higher->type == ACPI_STATE_C3)
- cx->promotion.threshold.bm = bm_history;
- }
-
- higher = cx;
- }
-
- return 0;
-}
-#endif /* !CONFIG_CPU_IDLE */
-
static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
{
*/
cx->valid = 1;
-#ifndef CONFIG_CPU_IDLE
- cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
-#else
cx->latency_ticks = cx->latency;
-#endif
return;
}
*/
cx->valid = 1;
-#ifndef CONFIG_CPU_IDLE
- cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
-#else
cx->latency_ticks = cx->latency;
-#endif
/*
* On older chipsets, BM_RLD needs to be set
* in order for Bus Master activity to wake the
pr->power.count = acpi_processor_power_verify(pr);
-#ifndef CONFIG_CPU_IDLE
- /*
- * Set Default Policy
- * ------------------
- * Now that we know which states are supported, set the default
- * policy. Note that this policy can be changed dynamically
- * (e.g. encourage deeper sleeps to conserve battery life when
- * not on AC).
- */
- result = acpi_processor_set_power_policy(pr);
- if (result)
- return result;
-#endif
-
/*
* if one state of type C2 or C3 is available, mark this
* CPU as being "idle manageable"
.release = single_release,
};
-#ifndef CONFIG_CPU_IDLE
-
-int acpi_processor_cst_has_changed(struct acpi_processor *pr)
-{
- int result = 0;
-
- if (boot_option_idle_override)
- return 0;
-
- if (!pr)
- return -EINVAL;
-
- if (nocst) {
- return -ENODEV;
- }
-
- if (!pr->flags.power_setup_done)
- return -ENODEV;
-
- /*
- * Fall back to the default idle loop, when pm_idle_save had
- * been initialized.
- */
- if (pm_idle_save) {
- pm_idle = pm_idle_save;
- /* Relies on interrupts forcing exit from idle. */
- synchronize_sched();
- }
-
- pr->flags.power = 0;
- result = acpi_processor_get_power_info(pr);
- if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
- pm_idle = acpi_processor_idle;
-
- return result;
-}
-
-#ifdef CONFIG_SMP
-static void smp_callback(void *v)
-{
- /* we already woke the CPU up, nothing more to do */
-}
-
-/*
- * This function gets called when a part of the kernel has a new latency
- * requirement. This means we need to get all processors out of their C-state,
- * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
- * wakes them all right up.
- */
-static int acpi_processor_latency_notify(struct notifier_block *b,
- unsigned long l, void *v)
-{
- smp_call_function(smp_callback, NULL, 1);
- return NOTIFY_OK;
-}
-
-static struct notifier_block acpi_processor_latency_notifier = {
- .notifier_call = acpi_processor_latency_notify,
-};
-
-#endif
-
-#else /* CONFIG_CPU_IDLE */
/**
* acpi_idle_bm_check - checks if bus master activity was detected
return ret;
}
-#endif /* CONFIG_CPU_IDLE */
-
int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
struct acpi_device *device)
{
"ACPI: processor limited to max C-state %d\n",
max_cstate);
first_run++;
-#if !defined(CONFIG_CPU_IDLE) && defined(CONFIG_SMP)
- pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY,
- &acpi_processor_latency_notifier);
-#endif
}
if (!pr)
* platforms that only support C1.
*/
if (pr->flags.power) {
-#ifdef CONFIG_CPU_IDLE
acpi_processor_setup_cpuidle(pr);
if (cpuidle_register_device(&pr->power.dev))
return -EIO;
-#endif
printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
for (i = 1; i <= pr->power.count; i++)
printk(" C%d[C%d]", i,
pr->power.states[i].type);
printk(")\n");
-
-#ifndef CONFIG_CPU_IDLE
- if (pr->id == 0) {
- pm_idle_save = pm_idle;
- pm_idle = acpi_processor_idle;
- }
-#endif
}
/* 'power' [R] */
if (boot_option_idle_override)
return 0;
-#ifdef CONFIG_CPU_IDLE
cpuidle_unregister_device(&pr->power.dev);
-#endif
pr->flags.power_setup_done = 0;
if (acpi_device_dir(device))
remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
acpi_device_dir(device));
-#ifndef CONFIG_CPU_IDLE
-
- /* Unregister the idle handler when processor #0 is removed. */
- if (pr->id == 0) {
- if (pm_idle_save)
- pm_idle = pm_idle_save;
-
- /*
- * We are about to unload the current idle thread pm callback
- * (pm_idle), Wait for all processors to update cached/local
- * copies of pm_idle before proceeding.
- */
- cpu_idle_wait();
-#ifdef CONFIG_SMP
- pm_qos_remove_notifier(PM_QOS_CPU_DMA_LATENCY,
- &acpi_processor_latency_notifier);
-#endif
- }
-#endif
-
return 0;
}
git.samba.org / sfrench / cifs-2.6.git / commitdiff