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linux/drivers/acpi/processor_idle.c

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/*
* processor_idle - idle state submodule to the ACPI processor driver
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
* Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
* - Added processor hotplug support
* Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
* - Added support for C3 on SMP
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/moduleparam.h>
#include <linux/sched.h> /* need_resched() */
#include <linux/pm_qos_params.h>
#include <linux/clockchips.h>
#include <linux/cpuidle.h>
/*
* Include the apic definitions for x86 to have the APIC timer related defines
* available also for UP (on SMP it gets magically included via linux/smp.h).
* asm/acpi.h is not an option, as it would require more include magic. Also
* creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
*/
#ifdef CONFIG_X86
#include <asm/apic.h>
#endif
#include <asm/io.h>
#include <asm/uaccess.h>
#include <acpi/acpi_bus.h>
#include <acpi/processor.h>
#define ACPI_PROCESSOR_COMPONENT 0x01000000
#define ACPI_PROCESSOR_CLASS "processor"
#define _COMPONENT ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_idle");
#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.
* For now disable this. Probably a bug somewhere else.
*
* To skip this limit, boot/load with a large max_cstate limit.
*/
static int set_max_cstate(const struct dmi_system_id *id)
{
if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
return 0;
printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
" Override with \"processor.max_cstate=%d\"\n", id->ident,
(long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
max_cstate = (long)id->driver_data;
return 0;
}
/* Actually this shouldn't be __cpuinitdata, would be better to fix the
callers to only run once -AK */
static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
{ set_max_cstate, "IBM ThinkPad R40e", {
DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
{ set_max_cstate, "Medion 41700", {
DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
{ set_max_cstate, "Clevo 5600D", {
DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
(void *)2},
{},
};
static inline u32 ticks_elapsed(u32 t1, u32 t2)
{
if (t2 >= t1)
return (t2 - t1);
else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
else
return ((0xFFFFFFFF - t1) + t2);
}
static inline u32 ticks_elapsed_in_us(u32 t1, u32 t2)
{
if (t2 >= t1)
return PM_TIMER_TICKS_TO_US(t2 - t1);
else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
return PM_TIMER_TICKS_TO_US(((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
else
return PM_TIMER_TICKS_TO_US((0xFFFFFFFF - t1) + t2);
}
/*
* Callers should disable interrupts before the call and enable
* interrupts after return.
*/
static void acpi_safe_halt(void)
{
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we
* test NEED_RESCHED:
*/
smp_mb();
if (!need_resched()) {
safe_halt();
local_irq_disable();
}
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;
/* Cleanup from old state. */
if (old) {
switch (old->type) {
case ACPI_STATE_C3:
/* Disable bus master reload */
if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
break;
}
}
/* Prepare to use new state. */
switch (new->type) {
case ACPI_STATE_C3:
/* Enable bus master reload */
if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
break;
}
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)
{
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);
}
}
#endif /* !CONFIG_CPU_IDLE */
#ifdef ARCH_APICTIMER_STOPS_ON_C3
/*
* Some BIOS implementations switch to C3 in the published C2 state.
* This seems to be a common problem on AMD boxen, but other vendors
* are affected too. We pick the most conservative approach: we assume
* that the local APIC stops in both C2 and C3.
*/
static void acpi_timer_check_state(int state, struct acpi_processor *pr,
struct acpi_processor_cx *cx)
{
struct acpi_processor_power *pwr = &pr->power;
u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
/*
* Check, if one of the previous states already marked the lapic
* unstable
*/
if (pwr->timer_broadcast_on_state < state)
return;
if (cx->type >= type)
pr->power.timer_broadcast_on_state = state;
}
static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
{
unsigned long reason;
reason = pr->power.timer_broadcast_on_state < INT_MAX ?
CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
clockevents_notify(reason, &pr->id);
}
/* Power(C) State timer broadcast control */
static void acpi_state_timer_broadcast(struct acpi_processor *pr,
struct acpi_processor_cx *cx,
int broadcast)
{
int state = cx - pr->power.states;
if (state >= pr->power.timer_broadcast_on_state) {
unsigned long reason;
reason = broadcast ? CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
clockevents_notify(reason, &pr->id);
}
}
#else
static void acpi_timer_check_state(int state, struct acpi_processor *pr,
struct acpi_processor_cx *cstate) { }
static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
static void acpi_state_timer_broadcast(struct acpi_processor *pr,
struct acpi_processor_cx *cx,
int broadcast)
{
}
#endif
/*
* Suspend / resume control
*/
static int acpi_idle_suspend;
int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
{
acpi_idle_suspend = 1;
return 0;
}
int acpi_processor_resume(struct acpi_device * device)
{
acpi_idle_suspend = 0;
return 0;
}
#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
static int tsc_halts_in_c(int state)
{
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_AMD:
/*
* AMD Fam10h TSC will tick in all
* C/P/S0/S1 states when this bit is set.
*/
if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
return 0;
/*FALL THROUGH*/
case X86_VENDOR_INTEL:
/* Several cases known where TSC halts in C2 too */
default:
return state > ACPI_STATE_C1;
}
}
#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 = processors[smp_processor_id()];
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(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)
{
if (!pr)
return -EINVAL;
if (!pr->pblk)
return -ENODEV;
/* if info is obtained from pblk/fadt, type equals state */
pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
#ifndef CONFIG_HOTPLUG_CPU
/*
* Check for P_LVL2_UP flag before entering C2 and above on
* an SMP system.
*/
if ((num_online_cpus() > 1) &&
!(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
return -ENODEV;
#endif
/* determine C2 and C3 address from pblk */
pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
/* determine latencies from FADT */
pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"lvl2[0x%08x] lvl3[0x%08x]\n",
pr->power.states[ACPI_STATE_C2].address,
pr->power.states[ACPI_STATE_C3].address));
return 0;
}
static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
{
if (!pr->power.states[ACPI_STATE_C1].valid) {
/* set the first C-State to C1 */
/* all processors need to support C1 */
pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
pr->power.states[ACPI_STATE_C1].valid = 1;
pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
}
/* the C0 state only exists as a filler in our array */
pr->power.states[ACPI_STATE_C0].valid = 1;
return 0;
}
static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
{
acpi_status status = 0;
acpi_integer count;
int current_count;
int i;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *cst;
if (nocst)
return -ENODEV;
current_count = 0;
status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
if (ACPI_FAILURE(status)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
return -ENODEV;
}
cst = buffer.pointer;
/* There must be at least 2 elements */
if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
printk(KERN_ERR PREFIX "not enough elements in _CST\n");
status = -EFAULT;
goto end;
}
count = cst->package.elements[0].integer.value;
/* Validate number of power states. */
if (count < 1 || count != cst->package.count - 1) {
printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
status = -EFAULT;
goto end;
}
/* Tell driver that at least _CST is supported. */
pr->flags.has_cst = 1;
for (i = 1; i <= count; i++) {
union acpi_object *element;
union acpi_object *obj;
struct acpi_power_register *reg;
struct acpi_processor_cx cx;
memset(&cx, 0, sizeof(cx));
element = &(cst->package.elements[i]);
if (element->type != ACPI_TYPE_PACKAGE)
continue;
if (element->package.count != 4)
continue;
obj = &(element->package.elements[0]);
if (obj->type != ACPI_TYPE_BUFFER)
continue;
reg = (struct acpi_power_register *)obj->buffer.pointer;
if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
(reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
continue;
/* There should be an easy way to extract an integer... */
obj = &(element->package.elements[1]);
if (obj->type != ACPI_TYPE_INTEGER)
continue;
cx.type = obj->integer.value;
/*
* Some buggy BIOSes won't list C1 in _CST -
* Let acpi_processor_get_power_info_default() handle them later
*/
if (i == 1 && cx.type != ACPI_STATE_C1)
current_count++;
cx.address = reg->address;
cx.index = current_count + 1;
cx.entry_method = ACPI_CSTATE_SYSTEMIO;
if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
if (acpi_processor_ffh_cstate_probe
(pr->id, &cx, reg) == 0) {
cx.entry_method = ACPI_CSTATE_FFH;
} else if (cx.type == ACPI_STATE_C1) {
/*
* C1 is a special case where FIXED_HARDWARE
* can be handled in non-MWAIT way as well.
* In that case, save this _CST entry info.
* Otherwise, ignore this info and continue.
*/
cx.entry_method = ACPI_CSTATE_HALT;
snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
} else {
continue;
}
} else {
snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
cx.address);
}
if (cx.type == ACPI_STATE_C1) {
cx.valid = 1;
}
obj = &(element->package.elements[2]);
if (obj->type != ACPI_TYPE_INTEGER)
continue;
cx.latency = obj->integer.value;
obj = &(element->package.elements[3]);
if (obj->type != ACPI_TYPE_INTEGER)
continue;
cx.power = obj->integer.value;
current_count++;
memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
/*
* We support total ACPI_PROCESSOR_MAX_POWER - 1
* (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
*/
if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
printk(KERN_WARNING
"Limiting number of power states to max (%d)\n",
ACPI_PROCESSOR_MAX_POWER);
printk(KERN_WARNING
"Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
break;
}
}
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
current_count));
/* Validate number of power states discovered */
if (current_count < 2)
status = -EFAULT;
end:
kfree(buffer.pointer);
return status;
}
static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
{
if (!cx->address)
return;
/*
* C2 latency must be less than or equal to 100
* microseconds.
*/
else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"latency too large [%d]\n", cx->latency));
return;
}
/*
* Otherwise we've met all of our C2 requirements.
* Normalize the C2 latency to expidite policy
*/
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;
}
static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
struct acpi_processor_cx *cx)
{
static int bm_check_flag;
if (!cx->address)
return;
/*
* C3 latency must be less than or equal to 1000
* microseconds.
*/
else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"latency too large [%d]\n", cx->latency));
return;
}
/*
* PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
* DMA transfers are used by any ISA device to avoid livelock.
* Note that we could disable Type-F DMA (as recommended by
* the erratum), but this is known to disrupt certain ISA
* devices thus we take the conservative approach.
*/
else if (errata.piix4.fdma) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"C3 not supported on PIIX4 with Type-F DMA\n"));
return;
}
/* All the logic here assumes flags.bm_check is same across all CPUs */
if (!bm_check_flag) {
/* Determine whether bm_check is needed based on CPU */
acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
bm_check_flag = pr->flags.bm_check;
} else {
pr->flags.bm_check = bm_check_flag;
}
if (pr->flags.bm_check) {
if (!pr->flags.bm_control) {
if (pr->flags.has_cst != 1) {
/* bus mastering control is necessary */
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"C3 support requires BM control\n"));
return;
} else {
/* Here we enter C3 without bus mastering */
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"C3 support without BM control\n"));
}
}
} else {
/*
* WBINVD should be set in fadt, for C3 state to be
* supported on when bm_check is not required.
*/
if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Cache invalidation should work properly"
" for C3 to be enabled on SMP systems\n"));
return;
}
acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
}
/*
* Otherwise we've met all of our C3 requirements.
* Normalize the C3 latency to expidite policy. Enable
* checking of bus mastering status (bm_check) so we can
* use this in our C3 policy
*/
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;
}
static int acpi_processor_power_verify(struct acpi_processor *pr)
{
unsigned int i;
unsigned int working = 0;
pr->power.timer_broadcast_on_state = INT_MAX;
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
struct acpi_processor_cx *cx = &pr->power.states[i];
switch (cx->type) {
case ACPI_STATE_C1:
cx->valid = 1;
break;
case ACPI_STATE_C2:
acpi_processor_power_verify_c2(cx);
if (cx->valid)
acpi_timer_check_state(i, pr, cx);
break;
case ACPI_STATE_C3:
acpi_processor_power_verify_c3(pr, cx);
if (cx->valid)
acpi_timer_check_state(i, pr, cx);
break;
}
if (cx->valid)
working++;
}
acpi_propagate_timer_broadcast(pr);
return (working);
}
static int acpi_processor_get_power_info(struct acpi_processor *pr)
{
unsigned int i;
int result;
/* NOTE: the idle thread may not be running while calling
* this function */
/* Zero initialize all the C-states info. */
memset(pr->power.states, 0, sizeof(pr->power.states));
result = acpi_processor_get_power_info_cst(pr);
if (result == -ENODEV)
result = acpi_processor_get_power_info_fadt(pr);
if (result)
return result;
acpi_processor_get_power_info_default(pr);
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"
*/
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
if (pr->power.states[i].valid) {
pr->power.count = i;
if (pr->power.states[i].type >= ACPI_STATE_C2)
pr->flags.power = 1;
}
}
return 0;
}
static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
{
struct acpi_processor *pr = seq->private;
unsigned int i;
if (!pr)
goto end;
seq_printf(seq, "active state: C%zd\n"
"max_cstate: C%d\n"
"bus master activity: %08x\n"
"maximum allowed latency: %d usec\n",
pr->power.state ? pr->power.state - pr->power.states : 0,
max_cstate, (unsigned)pr->power.bm_activity,
pm_qos_requirement(PM_QOS_CPU_DMA_LATENCY));
seq_puts(seq, "states:\n");
for (i = 1; i <= pr->power.count; i++) {
seq_printf(seq, " %cC%d: ",
(&pr->power.states[i] ==
pr->power.state ? '*' : ' '), i);
if (!pr->power.states[i].valid) {
seq_puts(seq, "<not supported>\n");
continue;
}
switch (pr->power.states[i].type) {
case ACPI_STATE_C1:
seq_printf(seq, "type[C1] ");
break;
case ACPI_STATE_C2:
seq_printf(seq, "type[C2] ");
break;
case ACPI_STATE_C3:
seq_printf(seq, "type[C3] ");
break;
default:
seq_printf(seq, "type[--] ");
break;
}
if (pr->power.states[i].promotion.state)
seq_printf(seq, "promotion[C%zd] ",
(pr->power.states[i].promotion.state -
pr->power.states));
else
seq_puts(seq, "promotion[--] ");
if (pr->power.states[i].demotion.state)
seq_printf(seq, "demotion[C%zd] ",
(pr->power.states[i].demotion.state -
pr->power.states));
else
seq_puts(seq, "demotion[--] ");
seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
pr->power.states[i].latency,
pr->power.states[i].usage,
(unsigned long long)pr->power.states[i].time);
}
end:
return 0;
}
static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
{
return single_open(file, acpi_processor_power_seq_show,
PDE(inode)->data);
}
static const struct file_operations acpi_processor_power_fops = {
.owner = THIS_MODULE,
.open = acpi_processor_power_open_fs,
.read = seq_read,
.llseek = seq_lseek,
.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 */
pm_idle = pm_idle_save;
synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
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, 0, 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
*/
static int acpi_idle_bm_check(void)
{
u32 bm_status = 0;
acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
if (bm_status)
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))
bm_status = 1;
}
return bm_status;
}
/**
* acpi_idle_update_bm_rld - updates the BM_RLD bit depending on target state
* @pr: the processor
* @target: the new target state
*/
static inline void acpi_idle_update_bm_rld(struct acpi_processor *pr,
struct acpi_processor_cx *target)
{
if (pr->flags.bm_rld_set && target->type != ACPI_STATE_C3) {
acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
pr->flags.bm_rld_set = 0;
}
if (!pr->flags.bm_rld_set && target->type == ACPI_STATE_C3) {
acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
pr->flags.bm_rld_set = 1;
}
}
/**
* acpi_idle_do_entry - a helper function that does C2 and C3 type entry
* @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)
{
if (cx->entry_method == ACPI_CSTATE_FFH) {
/* Call into architectural FFH based C-state */
acpi_processor_ffh_cstate_enter(cx);
} else if (cx->entry_method == ACPI_CSTATE_HALT) {
acpi_safe_halt();
} else {
int unused;
/* IO port based C-state */
inb(cx->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);
}
}
/**
* acpi_idle_enter_c1 - enters an ACPI C1 state-type
* @dev: the target CPU
* @state: the state data
*
* This is equivalent to the HALT instruction.
*/
static int acpi_idle_enter_c1(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
u32 t1, t2;
struct acpi_processor *pr;
struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
pr = processors[smp_processor_id()];
if (unlikely(!pr))
return 0;
local_irq_disable();
/* Do not access any ACPI IO ports in suspend path */
if (acpi_idle_suspend) {
acpi_safe_halt();
local_irq_enable();
return 0;
}
if (pr->flags.bm_check)
acpi_idle_update_bm_rld(pr, cx);
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
acpi_idle_do_entry(cx);
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
local_irq_enable();
cx->usage++;
return ticks_elapsed_in_us(t1, t2);
}
/**
* acpi_idle_enter_simple - enters an ACPI state without BM handling
* @dev: the target CPU
* @state: the state data
*/
static int acpi_idle_enter_simple(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
struct acpi_processor *pr;
struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
u32 t1, t2;
int sleep_ticks = 0;
pr = processors[smp_processor_id()];
if (unlikely(!pr))
return 0;
if (acpi_idle_suspend)
return(acpi_idle_enter_c1(dev, state));
local_irq_disable();
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we test
* NEED_RESCHED:
*/
smp_mb();
if (unlikely(need_resched())) {
current_thread_info()->status |= TS_POLLING;
local_irq_enable();
return 0;
}
/*
* Must be done before busmaster disable as we might need to
* access HPET !
*/
acpi_state_timer_broadcast(pr, cx, 1);
if (pr->flags.bm_check)
acpi_idle_update_bm_rld(pr, cx);
if (cx->type == ACPI_STATE_C3)
ACPI_FLUSH_CPU_CACHE();
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
/* Tell the scheduler that we are going deep-idle: */
sched_clock_idle_sleep_event();
acpi_idle_do_entry(cx);
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
/* TSC could halt in idle, so notify users */
if (tsc_halts_in_c(cx->type))
mark_tsc_unstable("TSC halts in idle");;
#endif
sleep_ticks = ticks_elapsed(t1, t2);
/* Tell the scheduler how much we idled: */
sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
local_irq_enable();
current_thread_info()->status |= TS_POLLING;
cx->usage++;
acpi_state_timer_broadcast(pr, cx, 0);
cx->time += sleep_ticks;
return ticks_elapsed_in_us(t1, t2);
}
static int c3_cpu_count;
static DEFINE_SPINLOCK(c3_lock);
/**
* acpi_idle_enter_bm - enters C3 with proper BM handling
* @dev: the target CPU
* @state: the state data
*
* If BM is detected, the deepest non-C3 idle state is entered instead.
*/
static int acpi_idle_enter_bm(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
struct acpi_processor *pr;
struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
u32 t1, t2;
int sleep_ticks = 0;
pr = processors[smp_processor_id()];
if (unlikely(!pr))
return 0;
if (acpi_idle_suspend)
return(acpi_idle_enter_c1(dev, state));
if (acpi_idle_bm_check()) {
if (dev->safe_state) {
return dev->safe_state->enter(dev, dev->safe_state);
} else {
local_irq_disable();
acpi_safe_halt();
local_irq_enable();
return 0;
}
}
local_irq_disable();
current_thread_info()->status &= ~TS_POLLING;
/*
* TS_POLLING-cleared state must be visible before we test
* NEED_RESCHED:
*/
smp_mb();
if (unlikely(need_resched())) {
current_thread_info()->status |= TS_POLLING;
local_irq_enable();
return 0;
}
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 !
*/
acpi_state_timer_broadcast(pr, cx, 1);
acpi_idle_update_bm_rld(pr, cx);
/*
* 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) {
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_set_register(ACPI_BITREG_ARB_DISABLE, 1);
spin_unlock(&c3_lock);
} else if (!pr->flags.bm_check) {
ACPI_FLUSH_CPU_CACHE();
}
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
acpi_idle_do_entry(cx);
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
/* Re-enable bus master arbitration */
if (pr->flags.bm_check && pr->flags.bm_control) {
spin_lock(&c3_lock);
acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
c3_cpu_count--;
spin_unlock(&c3_lock);
}
#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
/* TSC could halt in idle, so notify users */
if (tsc_halts_in_c(ACPI_STATE_C3))
mark_tsc_unstable("TSC halts in idle");
#endif
sleep_ticks = ticks_elapsed(t1, t2);
/* Tell the scheduler how much we idled: */
sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
local_irq_enable();
current_thread_info()->status |= TS_POLLING;
cx->usage++;
acpi_state_timer_broadcast(pr, cx, 0);
cx->time += sleep_ticks;
return ticks_elapsed_in_us(t1, t2);
}
struct cpuidle_driver acpi_idle_driver = {
.name = "acpi_idle",
.owner = THIS_MODULE,
};
/**
* acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
* @pr: the ACPI processor
*/
static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
{
int i, count = CPUIDLE_DRIVER_STATE_START;
struct acpi_processor_cx *cx;
struct cpuidle_state *state;
struct cpuidle_device *dev = &pr->power.dev;
if (!pr->flags.power_setup_done)
return -EINVAL;
if (pr->flags.power == 0) {
return -EINVAL;
}
dev->cpu = pr->id;
for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
dev->states[i].name[0] = '\0';
dev->states[i].desc[0] = '\0';
}
for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
cx = &pr->power.states[i];
state = &dev->states[count];
if (!cx->valid)
continue;
#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))
continue;
#endif
cpuidle_set_statedata(state, cx);
snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
state->exit_latency = cx->latency;
state->target_residency = cx->latency * latency_factor;
state->power_usage = cx->power;
state->flags = 0;
switch (cx->type) {
case ACPI_STATE_C1:
state->flags |= CPUIDLE_FLAG_SHALLOW;
if (cx->entry_method == ACPI_CSTATE_FFH)
state->flags |= CPUIDLE_FLAG_TIME_VALID;
state->enter = acpi_idle_enter_c1;
dev->safe_state = state;
break;
case ACPI_STATE_C2:
state->flags |= CPUIDLE_FLAG_BALANCED;
state->flags |= CPUIDLE_FLAG_TIME_VALID;
state->enter = acpi_idle_enter_simple;
dev->safe_state = state;
break;
case ACPI_STATE_C3:
state->flags |= CPUIDLE_FLAG_DEEP;
state->flags |= CPUIDLE_FLAG_TIME_VALID;
state->flags |= CPUIDLE_FLAG_CHECK_BM;
state->enter = pr->flags.bm_check ?
acpi_idle_enter_bm :
acpi_idle_enter_simple;
break;
}
count++;
if (count == CPUIDLE_STATE_MAX)
break;
}
dev->state_count = count;
if (!count)
return -EINVAL;
return 0;
}
int acpi_processor_cst_has_changed(struct acpi_processor *pr)
{
int ret = 0;
if (boot_option_idle_override)
return 0;
if (!pr)
return -EINVAL;
if (nocst) {
return -ENODEV;
}
if (!pr->flags.power_setup_done)
return -ENODEV;
cpuidle_pause_and_lock();
cpuidle_disable_device(&pr->power.dev);
acpi_processor_get_power_info(pr);
if (pr->flags.power) {
acpi_processor_setup_cpuidle(pr);
ret = cpuidle_enable_device(&pr->power.dev);
}
cpuidle_resume_and_unlock();
return ret;
}
#endif /* CONFIG_CPU_IDLE */
int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
struct acpi_device *device)
{
acpi_status status = 0;
static int first_run;
struct proc_dir_entry *entry = NULL;
unsigned int i;
if (boot_option_idle_override)
return 0;
if (!first_run) {
dmi_check_system(processor_power_dmi_table);
max_cstate = acpi_processor_cstate_check(max_cstate);
if (max_cstate < ACPI_C_STATES_MAX)
printk(KERN_NOTICE
"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)
return -EINVAL;
if (acpi_gbl_FADT.cst_control && !nocst) {
status =
acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"Notifying BIOS of _CST ability failed"));
}
}
acpi_processor_get_power_info(pr);
pr->flags.power_setup_done = 1;
/*
* Install the idle handler if processor power management is supported.
* Note that we use previously set idle handler will be used on
* 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++)
if (pr->power.states[i].valid)
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] */
entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER,
S_IRUGO, acpi_device_dir(device),
&acpi_processor_power_fops,
acpi_driver_data(device));
if (!entry)
return -EIO;
return 0;
}
int acpi_processor_power_exit(struct acpi_processor *pr,
struct acpi_device *device)
{
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) {
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;
}
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