source "arch/i386/kernel/cpu/cpufreq/Kconfig"
+source "drivers/cpuidle/Kconfig"
+
endmenu
menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
source "arch/x86_64/kernel/cpufreq/Kconfig"
+source "drivers/cpuidle/Kconfig"
+
endmenu
menu "Bus options (PCI etc.)"
obj-$(CONFIG_EISA) += eisa/
obj-$(CONFIG_LGUEST_GUEST) += lguest/
obj-$(CONFIG_CPU_FREQ) += cpufreq/
+obj-$(CONFIG_CPU_IDLE) += cpuidle/
obj-$(CONFIG_MMC) += mmc/
obj-$(CONFIG_NEW_LEDS) += leds/
obj-$(CONFIG_INFINIBAND) += infiniband/
__setup("acpi_wake_gpes_always_on", acpi_wake_gpes_always_on_setup);
/*
- * max_cstate is defined in the base kernel so modules can
- * change it w/o depending on the state of the processor module.
- */
-unsigned int max_cstate = ACPI_PROCESSOR_MAX_POWER;
-
-EXPORT_SYMBOL(max_cstate);
-
-/*
* Acquire a spinlock.
*
* handle is a pointer to the spinlock_t.
#include <linux/seq_file.h>
#include <linux/dmi.h>
#include <linux/moduleparam.h>
+#include <linux/cpuidle.h>
#include <asm/io.h>
#include <asm/system.h>
return -ENOMEM;
acpi_processor_dir->owner = THIS_MODULE;
+ result = cpuidle_register_driver(&acpi_idle_driver);
+ if (result < 0)
+ goto out_proc;
+
result = acpi_bus_register_driver(&acpi_processor_driver);
- if (result < 0) {
- remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
- return result;
- }
+ if (result < 0)
+ goto out_cpuidle;
acpi_processor_install_hotplug_notify();
acpi_processor_ppc_init();
return 0;
+
+out_cpuidle:
+ cpuidle_unregister_driver(&acpi_idle_driver);
+
+out_proc:
+ remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
+
+ return result;
}
static void __exit acpi_processor_exit(void)
{
-
acpi_processor_ppc_exit();
acpi_thermal_cpufreq_exit();
acpi_bus_unregister_driver(&acpi_processor_driver);
+ cpuidle_unregister_driver(&acpi_idle_driver);
+
remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
return;
#include <linux/sched.h> /* need_resched() */
#include <linux/latency.h>
#include <linux/clockchips.h>
+#include <linux/cpuidle.h>
/*
* Include the apic definitions for x86 to have the APIC timer related defines
#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;
-module_param(max_cstate, uint, 0644);
+#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;
+module_param(max_cstate, uint, 0000);
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
static unsigned int bm_history __read_mostly =
(HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
module_param(bm_history, uint, 0644);
-/* --------------------------------------------------------------------------
- Power Management
- -------------------------------------------------------------------------- */
+
+static int acpi_processor_set_power_policy(struct acpi_processor *pr);
+
+#endif
/*
* IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
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);
+}
+
+#ifndef CONFIG_CPU_IDLE
+
static void
acpi_processor_power_activate(struct acpi_processor *pr,
struct acpi_processor_cx *new)
unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
}
}
+#endif /* !CONFIG_CPU_IDLE */
#ifdef ARCH_APICTIMER_STOPS_ON_C3
return 0;
}
+#ifndef CONFIG_CPU_IDLE
static void acpi_processor_idle(void)
{
struct acpi_processor *pr = NULL;
* 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) &&
+ 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
return 0;
}
+#endif /* !CONFIG_CPU_IDLE */
static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
{
#ifndef CONFIG_HOTPLUG_CPU
/*
* Check for P_LVL2_UP flag before entering C2 and above on
- * an SMP system.
+ * an SMP system.
*/
if ((num_online_cpus() > 1) &&
!(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
* 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;
}
* 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;
}
pr->power.count = acpi_processor_power_verify(pr);
+#ifndef CONFIG_CPU_IDLE
/*
* Set Default Policy
* ------------------
result = acpi_processor_set_power_policy(pr);
if (result)
return result;
+#endif
/*
* if one state of type C2 or C3 is available, mark this
return 0;
}
-int acpi_processor_cst_has_changed(struct acpi_processor *pr)
-{
- int result = 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;
-}
-
-/* proc interface */
-
static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
{
struct acpi_processor *pr = seq->private;
.release = single_release,
};
+#ifndef CONFIG_CPU_IDLE
+
+int acpi_processor_cst_has_changed(struct acpi_processor *pr)
+{
+ int result = 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)
{
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
+ */
+static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
+{
+ if (cx->space_id == ACPI_CSTATE_FFH) {
+ /* Call into architectural FFH based C-state */
+ acpi_processor_ffh_cstate_enter(cx);
+ } 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)
+{
+ struct acpi_processor *pr;
+ struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
+ pr = processors[smp_processor_id()];
+
+ if (unlikely(!pr))
+ return 0;
+
+ if (pr->flags.bm_check)
+ acpi_idle_update_bm_rld(pr, cx);
+
+ 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();
+ current_thread_info()->status |= TS_POLLING;
+
+ cx->usage++;
+
+ return 0;
+}
+
+/**
+ * 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;
+ pr = processors[smp_processor_id()];
+
+ if (unlikely(!pr))
+ return 0;
+
+ if (acpi_idle_suspend)
+ return(acpi_idle_enter_c1(dev, state));
+
+ if (pr->flags.bm_check)
+ acpi_idle_update_bm_rld(pr, cx);
+
+ 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;
+ }
+
+ if (cx->type == ACPI_STATE_C3)
+ ACPI_FLUSH_CPU_CACHE();
+
+ t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+ acpi_state_timer_broadcast(pr, cx, 1);
+ acpi_idle_do_entry(cx);
+ t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+
+#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
+ /* TSC could halt in idle, so notify users */
+ mark_tsc_unstable("TSC halts in idle");;
+#endif
+
+ local_irq_enable();
+ current_thread_info()->status |= TS_POLLING;
+
+ cx->usage++;
+
+ acpi_state_timer_broadcast(pr, cx, 0);
+ cx->time += ticks_elapsed(t1, t2);
+ 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;
+ 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 (acpi_idle_bm_check()) {
+ cx = pr->power.bm_state;
+
+ 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);
+ } else {
+ acpi_idle_update_bm_rld(pr, cx);
+
+ 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);
+
+ t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+ acpi_idle_do_entry(cx);
+ t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+
+ spin_lock(&c3_lock);
+ /* Re-enable bus master arbitration */
+ if (c3_cpu_count == num_online_cpus())
+ acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
+ c3_cpu_count--;
+ spin_unlock(&c3_lock);
+ }
+
+#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC)
+ /* TSC could halt in idle, so notify users */
+ mark_tsc_unstable("TSC halts in idle");
+#endif
+
+ local_irq_enable();
+ current_thread_info()->status |= TS_POLLING;
+
+ cx->usage++;
+
+ acpi_state_timer_broadcast(pr, cx, 0);
+ cx->time += ticks_elapsed(t1, t2);
+ 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 = 0;
+ 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;
+ }
+
+ 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);
+ state->exit_latency = cx->latency;
+ state->target_residency = cx->latency * 6;
+ state->power_usage = cx->power;
+
+ state->flags = 0;
+ switch (cx->type) {
+ case ACPI_STATE_C1:
+ state->flags |= CPUIDLE_FLAG_SHALLOW;
+ state->enter = acpi_idle_enter_c1;
+ break;
+
+ case ACPI_STATE_C2:
+ state->flags |= CPUIDLE_FLAG_BALANCED;
+ state->flags |= CPUIDLE_FLAG_TIME_VALID;
+ state->enter = acpi_idle_enter_simple;
+ 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++;
+ }
+
+ dev->state_count = count;
+
+ if (!count)
+ return -EINVAL;
+
+ /* find the deepest state that can handle active BM */
+ if (pr->flags.bm_check) {
+ for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++)
+ if (pr->power.states[i].type == ACPI_STATE_C3)
+ break;
+ pr->power.bm_state = &pr->power.states[i-1];
+ }
+
+ return 0;
+}
+
+int acpi_processor_cst_has_changed(struct acpi_processor *pr)
+{
+ int ret;
+
+ 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);
+ 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: processor limited to max C-state %d\n",
max_cstate);
first_run++;
-#ifdef CONFIG_SMP
+#if !defined (CONFIG_CPU_IDLE) && defined (CONFIG_SMP)
register_latency_notifier(&acpi_processor_latency_notifier);
#endif
}
}
acpi_processor_get_power_info(pr);
+ pr->flags.power_setup_done = 1;
/*
* Install the idle handler if processor power management is supported.
* platforms that only support C1.
*/
if ((pr->flags.power) && (!boot_option_idle_override)) {
+#ifdef CONFIG_CPU_IDLE
+ acpi_processor_setup_cpuidle(pr);
+ pr->power.dev.cpu = pr->id;
+ 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)
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->owner = THIS_MODULE;
}
- pr->flags.power_setup_done = 1;
-
return 0;
}
int acpi_processor_power_exit(struct acpi_processor *pr,
struct acpi_device *device)
{
-
+#ifdef CONFIG_CPU_IDLE
+ if ((pr->flags.power) && (!boot_option_idle_override))
+ 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;
unregister_latency_notifier(&acpi_processor_latency_notifier);
#endif
}
+#endif
return 0;
}
--- /dev/null
+
+config CPU_IDLE
+ bool "CPU idle PM support"
+ help
+ CPU idle is a generic framework for supporting software-controlled
+ idle processor power management. It includes modular cross-platform
+ governors that can be swapped during runtime.
+
+ If you're using a mobile platform that supports CPU idle PM (e.g.
+ an ACPI-capable notebook), you should say Y here.
+
+config CPU_IDLE_GOV_LADDER
+ bool
+ depends on CPU_IDLE
+ default y
+
+config CPU_IDLE_GOV_MENU
+ bool
+ depends on CPU_IDLE && NO_HZ
+ default y
--- /dev/null
+#
+# Makefile for cpuidle.
+#
+
+obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
--- /dev/null
+/*
+ * cpuidle.c - core cpuidle infrastructure
+ *
+ * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ * Shaohua Li <shaohua.li@intel.com>
+ * Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/notifier.h>
+#include <linux/latency.h>
+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+
+#include "cpuidle.h"
+
+DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
+EXPORT_PER_CPU_SYMBOL_GPL(cpuidle_devices);
+
+DEFINE_MUTEX(cpuidle_lock);
+LIST_HEAD(cpuidle_detected_devices);
+static void (*pm_idle_old)(void);
+
+static int enabled_devices;
+
+/**
+ * cpuidle_idle_call - the main idle loop
+ *
+ * NOTE: no locks or semaphores should be used here
+ */
+static void cpuidle_idle_call(void)
+{
+ struct cpuidle_device *dev = __get_cpu_var(cpuidle_devices);
+ struct cpuidle_state *target_state;
+ int next_state;
+
+ /* check if the device is ready */
+ if (!dev || !dev->enabled) {
+ if (pm_idle_old)
+ pm_idle_old();
+ else
+ local_irq_enable();
+ return;
+ }
+
+ /* ask the governor for the next state */
+ next_state = cpuidle_curr_governor->select(dev);
+ if (need_resched())
+ return;
+ target_state = &dev->states[next_state];
+
+ /* enter the state and update stats */
+ dev->last_residency = target_state->enter(dev, target_state);
+ dev->last_state = target_state;
+ target_state->time += dev->last_residency;
+ target_state->usage++;
+
+ /* give the governor an opportunity to reflect on the outcome */
+ if (cpuidle_curr_governor->reflect)
+ cpuidle_curr_governor->reflect(dev);
+}
+
+/**
+ * cpuidle_install_idle_handler - installs the cpuidle idle loop handler
+ */
+void cpuidle_install_idle_handler(void)
+{
+ if (enabled_devices && (pm_idle != cpuidle_idle_call)) {
+ /* Make sure all changes finished before we switch to new idle */
+ smp_wmb();
+ pm_idle = cpuidle_idle_call;
+ }
+}
+
+/**
+ * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler
+ */
+void cpuidle_uninstall_idle_handler(void)
+{
+ if (enabled_devices && (pm_idle != pm_idle_old)) {
+ pm_idle = pm_idle_old;
+ cpu_idle_wait();
+ }
+}
+
+/**
+ * cpuidle_pause_and_lock - temporarily disables CPUIDLE
+ */
+void cpuidle_pause_and_lock(void)
+{
+ mutex_lock(&cpuidle_lock);
+ cpuidle_uninstall_idle_handler();
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock);
+
+/**
+ * cpuidle_resume_and_unlock - resumes CPUIDLE operation
+ */
+void cpuidle_resume_and_unlock(void)
+{
+ cpuidle_install_idle_handler();
+ mutex_unlock(&cpuidle_lock);
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock);
+
+/**
+ * cpuidle_enable_device - enables idle PM for a CPU
+ * @dev: the CPU
+ *
+ * This function must be called between cpuidle_pause_and_lock and
+ * cpuidle_resume_and_unlock when used externally.
+ */
+int cpuidle_enable_device(struct cpuidle_device *dev)
+{
+ int ret, i;
+
+ if (dev->enabled)
+ return 0;
+ if (!cpuidle_curr_driver || !cpuidle_curr_governor)
+ return -EIO;
+ if (!dev->state_count)
+ return -EINVAL;
+
+ if ((ret = cpuidle_add_state_sysfs(dev)))
+ return ret;
+
+ if (cpuidle_curr_governor->enable &&
+ (ret = cpuidle_curr_governor->enable(dev)))
+ goto fail_sysfs;
+
+ for (i = 0; i < dev->state_count; i++) {
+ dev->states[i].usage = 0;
+ dev->states[i].time = 0;
+ }
+ dev->last_residency = 0;
+ dev->last_state = NULL;
+
+ smp_wmb();
+
+ dev->enabled = 1;
+
+ enabled_devices++;
+ return 0;
+
+fail_sysfs:
+ cpuidle_remove_state_sysfs(dev);
+
+ return ret;
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_enable_device);
+
+/**
+ * cpuidle_disable_device - disables idle PM for a CPU
+ * @dev: the CPU
+ *
+ * This function must be called between cpuidle_pause_and_lock and
+ * cpuidle_resume_and_unlock when used externally.
+ */
+void cpuidle_disable_device(struct cpuidle_device *dev)
+{
+ if (!dev->enabled)
+ return;
+ if (!cpuidle_curr_driver || !cpuidle_curr_governor)
+ return;
+
+ dev->enabled = 0;
+
+ if (cpuidle_curr_governor->disable)
+ cpuidle_curr_governor->disable(dev);
+
+ cpuidle_remove_state_sysfs(dev);
+ enabled_devices--;
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_disable_device);
+
+/**
+ * cpuidle_register_device - registers a CPU's idle PM feature
+ * @dev: the cpu
+ */
+int cpuidle_register_device(struct cpuidle_device *dev)
+{
+ int ret;
+ struct sys_device *sys_dev = get_cpu_sysdev((unsigned long)dev->cpu);
+
+ if (!sys_dev)
+ return -EINVAL;
+ if (!try_module_get(cpuidle_curr_driver->owner))
+ return -EINVAL;
+
+ init_completion(&dev->kobj_unregister);
+
+ mutex_lock(&cpuidle_lock);
+
+ per_cpu(cpuidle_devices, dev->cpu) = dev;
+ list_add(&dev->device_list, &cpuidle_detected_devices);
+ if ((ret = cpuidle_add_sysfs(sys_dev))) {
+ mutex_unlock(&cpuidle_lock);
+ module_put(cpuidle_curr_driver->owner);
+ return ret;
+ }
+
+ cpuidle_enable_device(dev);
+ cpuidle_install_idle_handler();
+
+ mutex_unlock(&cpuidle_lock);
+
+ return 0;
+
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_register_device);
+
+/**
+ * cpuidle_unregister_device - unregisters a CPU's idle PM feature
+ * @dev: the cpu
+ */
+void cpuidle_unregister_device(struct cpuidle_device *dev)
+{
+ struct sys_device *sys_dev = get_cpu_sysdev((unsigned long)dev->cpu);
+
+ cpuidle_pause_and_lock();
+
+ cpuidle_disable_device(dev);
+
+ cpuidle_remove_sysfs(sys_dev);
+ list_del(&dev->device_list);
+ wait_for_completion(&dev->kobj_unregister);
+ per_cpu(cpuidle_devices, dev->cpu) = NULL;
+
+ cpuidle_resume_and_unlock();
+
+ module_put(cpuidle_curr_driver->owner);
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_unregister_device);
+
+#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 cpuidle_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 cpuidle_latency_notifier = {
+ .notifier_call = cpuidle_latency_notify,
+};
+
+#define latency_notifier_init(x) do { register_latency_notifier(x); } while (0)
+
+#else /* CONFIG_SMP */
+
+#define latency_notifier_init(x) do { } while (0)
+
+#endif /* CONFIG_SMP */
+
+/**
+ * cpuidle_init - core initializer
+ */
+static int __init cpuidle_init(void)
+{
+ int ret;
+
+ pm_idle_old = pm_idle;
+
+ ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
+ if (ret)
+ return ret;
+
+ latency_notifier_init(&cpuidle_latency_notifier);
+
+ return 0;
+}
+
+core_initcall(cpuidle_init);
--- /dev/null
+/*
+ * cpuidle.h - The internal header file
+ */
+
+#ifndef __DRIVER_CPUIDLE_H
+#define __DRIVER_CPUIDLE_H
+
+#include <linux/sysdev.h>
+
+/* For internal use only */
+extern struct cpuidle_governor *cpuidle_curr_governor;
+extern struct cpuidle_driver *cpuidle_curr_driver;
+extern struct list_head cpuidle_governors;
+extern struct list_head cpuidle_detected_devices;
+extern struct mutex cpuidle_lock;
+extern spinlock_t cpuidle_driver_lock;
+
+/* idle loop */
+extern void cpuidle_install_idle_handler(void);
+extern void cpuidle_uninstall_idle_handler(void);
+
+/* governors */
+extern int cpuidle_switch_governor(struct cpuidle_governor *gov);
+
+/* sysfs */
+extern int cpuidle_add_class_sysfs(struct sysdev_class *cls);
+extern void cpuidle_remove_class_sysfs(struct sysdev_class *cls);
+extern int cpuidle_add_state_sysfs(struct cpuidle_device *device);
+extern void cpuidle_remove_state_sysfs(struct cpuidle_device *device);
+extern int cpuidle_add_sysfs(struct sys_device *sysdev);
+extern void cpuidle_remove_sysfs(struct sys_device *sysdev);
+
+#endif /* __DRIVER_CPUIDLE_H */
--- /dev/null
+/*
+ * driver.c - driver support
+ *
+ * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ * Shaohua Li <shaohua.li@intel.com>
+ * Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/cpuidle.h>
+
+#include "cpuidle.h"
+
+struct cpuidle_driver *cpuidle_curr_driver;
+DEFINE_SPINLOCK(cpuidle_driver_lock);
+
+/**
+ * cpuidle_register_driver - registers a driver
+ * @drv: the driver
+ */
+int cpuidle_register_driver(struct cpuidle_driver *drv)
+{
+ if (!drv)
+ return -EINVAL;
+
+ spin_lock(&cpuidle_driver_lock);
+ if (cpuidle_curr_driver) {
+ spin_unlock(&cpuidle_driver_lock);
+ return -EBUSY;
+ }
+ cpuidle_curr_driver = drv;
+ spin_unlock(&cpuidle_driver_lock);
+
+ return 0;
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_register_driver);
+
+/**
+ * cpuidle_unregister_driver - unregisters a driver
+ * @drv: the driver
+ */
+void cpuidle_unregister_driver(struct cpuidle_driver *drv)
+{
+ if (!drv)
+ return;
+
+ spin_lock(&cpuidle_driver_lock);
+ cpuidle_curr_driver = NULL;
+ spin_unlock(&cpuidle_driver_lock);
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);
--- /dev/null
+/*
+ * governor.c - governor support
+ *
+ * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ * Shaohua Li <shaohua.li@intel.com>
+ * Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/cpuidle.h>
+
+#include "cpuidle.h"
+
+LIST_HEAD(cpuidle_governors);
+struct cpuidle_governor *cpuidle_curr_governor;
+
+/**
+ * __cpuidle_find_governor - finds a governor of the specified name
+ * @str: the name
+ *
+ * Must be called with cpuidle_lock aquired.
+ */
+static struct cpuidle_governor * __cpuidle_find_governor(const char *str)
+{
+ struct cpuidle_governor *gov;
+
+ list_for_each_entry(gov, &cpuidle_governors, governor_list)
+ if (!strnicmp(str, gov->name, CPUIDLE_NAME_LEN))
+ return gov;
+
+ return NULL;
+}
+
+/**
+ * cpuidle_switch_governor - changes the governor
+ * @gov: the new target governor
+ *
+ * NOTE: "gov" can be NULL to specify disabled
+ * Must be called with cpuidle_lock aquired.
+ */
+int cpuidle_switch_governor(struct cpuidle_governor *gov)
+{
+ struct cpuidle_device *dev;
+
+ if (gov == cpuidle_curr_governor)
+ return 0;
+
+ cpuidle_uninstall_idle_handler();
+
+ if (cpuidle_curr_governor) {
+ list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
+ cpuidle_disable_device(dev);
+ module_put(cpuidle_curr_governor->owner);
+ }
+
+ cpuidle_curr_governor = gov;
+
+ if (gov) {
+ if (!try_module_get(cpuidle_curr_governor->owner))
+ return -EINVAL;
+ list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
+ cpuidle_enable_device(dev);
+ cpuidle_install_idle_handler();
+ printk(KERN_INFO "cpuidle: using governor %s\n", gov->name);
+ }
+
+ return 0;
+}
+
+/**
+ * cpuidle_register_governor - registers a governor
+ * @gov: the governor
+ */
+int cpuidle_register_governor(struct cpuidle_governor *gov)
+{
+ int ret = -EEXIST;
+
+ if (!gov || !gov->select)
+ return -EINVAL;
+
+ mutex_lock(&cpuidle_lock);
+ if (__cpuidle_find_governor(gov->name) == NULL) {
+ ret = 0;
+ list_add_tail(&gov->governor_list, &cpuidle_governors);
+ if (!cpuidle_curr_governor ||
+ cpuidle_curr_governor->rating < gov->rating)
+ cpuidle_switch_governor(gov);
+ }
+ mutex_unlock(&cpuidle_lock);
+
+ return ret;
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_register_governor);
+
+/**
+ * cpuidle_replace_governor - find a replacement governor
+ * @exclude_rating: the rating that will be skipped while looking for
+ * new governor.
+ */
+static struct cpuidle_governor *cpuidle_replace_governor(int exclude_rating)
+{
+ struct cpuidle_governor *gov;
+ struct cpuidle_governor *ret_gov = NULL;
+ unsigned int max_rating = 0;
+
+ list_for_each_entry(gov, &cpuidle_governors, governor_list) {
+ if (gov->rating == exclude_rating)
+ continue;
+ if (gov->rating > max_rating) {
+ max_rating = gov->rating;
+ ret_gov = gov;
+ }
+ }
+
+ return ret_gov;
+}
+
+/**
+ * cpuidle_unregister_governor - unregisters a governor
+ * @gov: the governor
+ */
+void cpuidle_unregister_governor(struct cpuidle_governor *gov)
+{
+ if (!gov)
+ return;
+
+ mutex_lock(&cpuidle_lock);
+ if (gov == cpuidle_curr_governor) {
+ struct cpuidle_governor *new_gov;
+ new_gov = cpuidle_replace_governor(gov->rating);
+ cpuidle_switch_governor(new_gov);
+ }
+ list_del(&gov->governor_list);
+ mutex_unlock(&cpuidle_lock);
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_unregister_governor);
--- /dev/null
+#
+# Makefile for cpuidle governors.
+#
+
+obj-$(CONFIG_CPU_IDLE_GOV_LADDER) += ladder.o
+obj-$(CONFIG_CPU_IDLE_GOV_MENU) += menu.o
--- /dev/null
+/*
+ * ladder.c - the residency ladder algorithm
+ *
+ * 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>
+ *
+ * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ * Shaohua Li <shaohua.li@intel.com>
+ * Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpuidle.h>
+#include <linux/latency.h>
+#include <linux/moduleparam.h>
+#include <linux/jiffies.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#define PROMOTION_COUNT 4
+#define DEMOTION_COUNT 1
+
+struct ladder_device_state {
+ struct {
+ u32 promotion_count;
+ u32 demotion_count;
+ u32 promotion_time;
+ u32 demotion_time;
+ } threshold;
+ struct {
+ int promotion_count;
+ int demotion_count;
+ } stats;
+};
+
+struct ladder_device {
+ struct ladder_device_state states[CPUIDLE_STATE_MAX];
+ int last_state_idx;
+};
+
+static DEFINE_PER_CPU(struct ladder_device, ladder_devices);
+
+/**
+ * ladder_do_selection - prepares private data for a state change
+ * @ldev: the ladder device
+ * @old_idx: the current state index
+ * @new_idx: the new target state index
+ */
+static inline void ladder_do_selection(struct ladder_device *ldev,
+ int old_idx, int new_idx)
+{
+ ldev->states[old_idx].stats.promotion_count = 0;
+ ldev->states[old_idx].stats.demotion_count = 0;
+ ldev->last_state_idx = new_idx;
+}
+
+/**
+ * ladder_select_state - selects the next state to enter
+ * @dev: the CPU
+ */
+static int ladder_select_state(struct cpuidle_device *dev)
+{
+ struct ladder_device *ldev = &__get_cpu_var(ladder_devices);
+ struct ladder_device_state *last_state;
+ int last_residency, last_idx = ldev->last_state_idx;
+
+ if (unlikely(!ldev))
+ return 0;
+
+ last_state = &ldev->states[last_idx];
+
+ if (dev->states[last_idx].flags & CPUIDLE_FLAG_TIME_VALID)
+ last_residency = cpuidle_get_last_residency(dev) - dev->states[last_idx].exit_latency;
+ else
+ last_residency = last_state->threshold.promotion_time + 1;
+
+ /* consider promotion */
+ if (last_idx < dev->state_count - 1 &&
+ last_residency > last_state->threshold.promotion_time &&
+ dev->states[last_idx + 1].exit_latency <= system_latency_constraint()) {
+ last_state->stats.promotion_count++;
+ last_state->stats.demotion_count = 0;
+ if (last_state->stats.promotion_count >= last_state->threshold.promotion_count) {
+ ladder_do_selection(ldev, last_idx, last_idx + 1);
+ return last_idx + 1;
+ }
+ }
+
+ /* consider demotion */
+ if (last_idx > 0 &&
+ last_residency < last_state->threshold.demotion_time) {
+ last_state->stats.demotion_count++;
+ last_state->stats.promotion_count = 0;
+ if (last_state->stats.demotion_count >= last_state->threshold.demotion_count) {
+ ladder_do_selection(ldev, last_idx, last_idx - 1);
+ return last_idx - 1;
+ }
+ }
+
+ /* otherwise remain at the current state */
+ return last_idx;
+}
+
+/**
+ * ladder_enable_device - setup for the governor
+ * @dev: the CPU
+ */
+static int ladder_enable_device(struct cpuidle_device *dev)
+{
+ int i;
+ struct ladder_device *ldev = &per_cpu(ladder_devices, dev->cpu);
+ struct ladder_device_state *lstate;
+ struct cpuidle_state *state;
+
+ ldev->last_state_idx = 0;
+
+ for (i = 0; i < dev->state_count; i++) {
+ state = &dev->states[i];
+ lstate = &ldev->states[i];
+
+ lstate->stats.promotion_count = 0;
+ lstate->stats.demotion_count = 0;
+
+ lstate->threshold.promotion_count = PROMOTION_COUNT;
+ lstate->threshold.demotion_count = DEMOTION_COUNT;
+
+ if (i < dev->state_count - 1)
+ lstate->threshold.promotion_time = state->exit_latency;
+ if (i > 0)
+ lstate->threshold.demotion_time = state->exit_latency;
+ }
+
+ return 0;
+}
+
+static struct cpuidle_governor ladder_governor = {
+ .name = "ladder",
+ .rating = 10,
+ .enable = ladder_enable_device,
+ .select = ladder_select_state,
+ .owner = THIS_MODULE,
+};
+
+/**
+ * init_ladder - initializes the governor
+ */
+static int __init init_ladder(void)
+{
+ return cpuidle_register_governor(&ladder_governor);
+}
+
+/**
+ * exit_ladder - exits the governor
+ */
+static void __exit exit_ladder(void)
+{
+ cpuidle_unregister_governor(&ladder_governor);
+}
+
+MODULE_LICENSE("GPL");
+module_init(init_ladder);
+module_exit(exit_ladder);
--- /dev/null
+/*
+ * menu.c - the menu idle governor
+ *
+ * Copyright (C) 2006-2007 Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpuidle.h>
+#include <linux/latency.h>
+#include <linux/time.h>
+#include <linux/ktime.h>
+#include <linux/hrtimer.h>
+#include <linux/tick.h>
+
+#define BREAK_FUZZ 4 /* 4 us */
+
+struct menu_device {
+ int last_state_idx;
+
+ unsigned int expected_us;
+ unsigned int predicted_us;
+ unsigned int last_measured_us;
+ unsigned int elapsed_us;
+};
+
+static DEFINE_PER_CPU(struct menu_device, menu_devices);
+
+/**
+ * menu_select - selects the next idle state to enter
+ * @dev: the CPU
+ */
+static int menu_select(struct cpuidle_device *dev)
+{
+ struct menu_device *data = &__get_cpu_var(menu_devices);
+ int i;
+
+ /* determine the expected residency time */
+ data->expected_us =
+ (u32) ktime_to_ns(tick_nohz_get_sleep_length()) / 1000;
+
+ /* find the deepest idle state that satisfies our constraints */
+ for (i = 1; i < dev->state_count; i++) {
+ struct cpuidle_state *s = &dev->states[i];
+
+ if (s->target_residency > data->expected_us)
+ break;
+ if (s->target_residency > data->predicted_us)
+ break;
+ if (s->exit_latency > system_latency_constraint())
+ break;
+ }
+
+ data->last_state_idx = i - 1;
+ return i - 1;
+}
+
+/**
+ * menu_reflect - attempts to guess what happened after entry
+ * @dev: the CPU
+ *
+ * NOTE: it's important to be fast here because this operation will add to
+ * the overall exit latency.
+ */
+static void menu_reflect(struct cpuidle_device *dev)
+{
+ struct menu_device *data = &__get_cpu_var(menu_devices);
+ int last_idx = data->last_state_idx;
+ unsigned int measured_us =
+ cpuidle_get_last_residency(dev) + data->elapsed_us;
+ struct cpuidle_state *target = &dev->states[last_idx];
+
+ /*
+ * Ugh, this idle state doesn't support residency measurements, so we
+ * are basically lost in the dark. As a compromise, assume we slept
+ * for one full standard timer tick. However, be aware that this
+ * could potentially result in a suboptimal state transition.
+ */
+ if (!(target->flags & CPUIDLE_FLAG_TIME_VALID))
+ measured_us = USEC_PER_SEC / HZ;
+
+ /* Predict time remaining until next break event */
+ if (measured_us + BREAK_FUZZ < data->expected_us - target->exit_latency) {
+ data->predicted_us = max(measured_us, data->last_measured_us);
+ data->last_measured_us = measured_us;
+ data->elapsed_us = 0;
+ } else {
+ if (data->elapsed_us < data->elapsed_us + measured_us)
+ data->elapsed_us = measured_us;
+ else
+ data->elapsed_us = -1;
+ data->predicted_us = max(measured_us, data->last_measured_us);
+ }
+}
+
+/**
+ * menu_enable_device - scans a CPU's states and does setup
+ * @dev: the CPU
+ */
+static int menu_enable_device(struct cpuidle_device *dev)
+{
+ struct menu_device *data = &per_cpu(menu_devices, dev->cpu);
+
+ memset(data, 0, sizeof(struct menu_device));
+
+ return 0;
+}
+
+static struct cpuidle_governor menu_governor = {
+ .name = "menu",
+ .rating = 20,
+ .enable = menu_enable_device,
+ .select = menu_select,
+ .reflect = menu_reflect,
+ .owner = THIS_MODULE,
+};
+
+/**
+ * init_menu - initializes the governor
+ */
+static int __init init_menu(void)
+{
+ return cpuidle_register_governor(&menu_governor);
+}
+
+/**
+ * exit_menu - exits the governor
+ */
+static void __exit exit_menu(void)
+{
+ cpuidle_unregister_governor(&menu_governor);
+}
+
+MODULE_LICENSE("GPL");
+module_init(init_menu);
+module_exit(exit_menu);
--- /dev/null
+/*
+ * sysfs.c - sysfs support
+ *
+ * (C) 2006-2007 Shaohua Li <shaohua.li@intel.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpuidle.h>
+#include <linux/sysfs.h>
+#include <linux/cpu.h>
+
+#include "cpuidle.h"
+
+static unsigned int sysfs_switch;
+static int __init cpuidle_sysfs_setup(char *unused)
+{
+ sysfs_switch = 1;
+ return 1;
+}
+__setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
+
+static ssize_t show_available_governors(struct sys_device *dev, char *buf)
+{
+ ssize_t i = 0;
+ struct cpuidle_governor *tmp;
+
+ mutex_lock(&cpuidle_lock);
+ list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
+ if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) - CPUIDLE_NAME_LEN - 2))
+ goto out;
+ i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
+ }
+
+out:
+ i+= sprintf(&buf[i], "\n");
+ mutex_unlock(&cpuidle_lock);
+ return i;
+}
+
+static ssize_t show_current_driver(struct sys_device *dev, char *buf)
+{
+ ssize_t ret;
+
+ spin_lock(&cpuidle_driver_lock);
+ if (cpuidle_curr_driver)
+ ret = sprintf(buf, "%s\n", cpuidle_curr_driver->name);
+ else
+ ret = sprintf(buf, "none\n");
+ spin_unlock(&cpuidle_driver_lock);
+
+ return ret;
+}
+
+static ssize_t show_current_governor(struct sys_device *dev, char *buf)
+{
+ ssize_t ret;
+
+ mutex_lock(&cpuidle_lock);
+ if (cpuidle_curr_governor)
+ ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
+ else
+ ret = sprintf(buf, "none\n");
+ mutex_unlock(&cpuidle_lock);
+
+ return ret;
+}
+
+static ssize_t store_current_governor(struct sys_device *dev,
+ const char *buf, size_t count)
+{
+ char gov_name[CPUIDLE_NAME_LEN];
+ int ret = -EINVAL;
+ size_t len = count;
+ struct cpuidle_governor *gov;
+
+ if (!len || len >= sizeof(gov_name))
+ return -EINVAL;
+
+ memcpy(gov_name, buf, len);
+ gov_name[len] = '\0';
+ if (gov_name[len - 1] == '\n')
+ gov_name[--len] = '\0';
+
+ mutex_lock(&cpuidle_lock);
+
+ list_for_each_entry(gov, &cpuidle_governors, governor_list) {
+ if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
+ ret = cpuidle_switch_governor(gov);
+ break;
+ }
+ }
+
+ mutex_unlock(&cpuidle_lock);
+
+ if (ret)
+ return ret;
+ else
+ return count;
+}
+
+static SYSDEV_ATTR(current_driver, 0444, show_current_driver, NULL);
+static SYSDEV_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
+
+static struct attribute *cpuclass_default_attrs[] = {
+ &attr_current_driver.attr,
+ &attr_current_governor_ro.attr,
+ NULL
+};
+
+static SYSDEV_ATTR(available_governors, 0444, show_available_governors, NULL);
+static SYSDEV_ATTR(current_governor, 0644, show_current_governor,
+ store_current_governor);
+
+static struct attribute *cpuclass_switch_attrs[] = {
+ &attr_available_governors.attr,
+ &attr_current_driver.attr,
+ &attr_current_governor.attr,
+ NULL
+};
+
+static struct attribute_group cpuclass_attr_group = {
+ .attrs = cpuclass_default_attrs,
+ .name = "cpuidle",
+};
+
+/**
+ * cpuidle_add_class_sysfs - add CPU global sysfs attributes
+ */
+int cpuidle_add_class_sysfs(struct sysdev_class *cls)
+{
+ if (sysfs_switch)
+ cpuclass_attr_group.attrs = cpuclass_switch_attrs;
+
+ return sysfs_create_group(&cls->kset.kobj, &cpuclass_attr_group);
+}
+
+/**
+ * cpuidle_remove_class_sysfs - remove CPU global sysfs attributes
+ */
+void cpuidle_remove_class_sysfs(struct sysdev_class *cls)
+{
+ sysfs_remove_group(&cls->kset.kobj, &cpuclass_attr_group);
+}
+
+struct cpuidle_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct cpuidle_device *, char *);
+ ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
+};
+
+#define define_one_ro(_name, show) \
+ static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
+#define define_one_rw(_name, show, store) \
+ static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
+
+#define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
+#define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
+static ssize_t cpuidle_show(struct kobject * kobj, struct attribute * attr ,char * buf)
+{
+ int ret = -EIO;
+ struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
+ struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
+
+ if (cattr->show) {
+ mutex_lock(&cpuidle_lock);
+ ret = cattr->show(dev, buf);
+ mutex_unlock(&cpuidle_lock);
+ }
+ return ret;
+}
+
+static ssize_t cpuidle_store(struct kobject * kobj, struct attribute * attr,
+ const char * buf, size_t count)
+{
+ int ret = -EIO;
+ struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
+ struct cpuidle_attr * cattr = attr_to_cpuidleattr(attr);
+
+ if (cattr->store) {
+ mutex_lock(&cpuidle_lock);
+ ret = cattr->store(dev, buf, count);
+ mutex_unlock(&cpuidle_lock);
+ }
+ return ret;
+}
+
+static struct sysfs_ops cpuidle_sysfs_ops = {
+ .show = cpuidle_show,
+ .store = cpuidle_store,
+};
+
+static void cpuidle_sysfs_release(struct kobject *kobj)
+{
+ struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
+
+ complete(&dev->kobj_unregister);
+}
+
+static struct kobj_type ktype_cpuidle = {
+ .sysfs_ops = &cpuidle_sysfs_ops,
+ .release = cpuidle_sysfs_release,
+};
+
+struct cpuidle_state_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct cpuidle_state *, char *);
+ ssize_t (*store)(struct cpuidle_state *, const char *, size_t);
+};
+
+#define define_one_state_ro(_name, show) \
+static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
+
+#define define_show_state_function(_name) \
+static ssize_t show_state_##_name(struct cpuidle_state *state, char *buf) \
+{ \
+ return sprintf(buf, "%u\n", state->_name);\
+}
+
+static ssize_t show_state_name(struct cpuidle_state *state, char *buf)
+{
+ return sprintf(buf, "%s\n", state->name);
+}
+
+define_show_state_function(exit_latency)
+define_show_state_function(power_usage)
+define_show_state_function(usage)
+define_show_state_function(time)
+define_one_state_ro(name, show_state_name);
+define_one_state_ro(latency, show_state_exit_latency);
+define_one_state_ro(power, show_state_power_usage);
+define_one_state_ro(usage, show_state_usage);
+define_one_state_ro(time, show_state_time);
+
+static struct attribute *cpuidle_state_default_attrs[] = {
+ &attr_name.attr,
+ &attr_latency.attr,
+ &attr_power.attr,
+ &attr_usage.attr,
+ &attr_time.attr,
+ NULL
+};
+
+#define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
+#define kobj_to_state(k) (kobj_to_state_obj(k)->state)
+#define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
+static ssize_t cpuidle_state_show(struct kobject * kobj,
+ struct attribute * attr ,char * buf)
+{
+ int ret = -EIO;
+ struct cpuidle_state *state = kobj_to_state(kobj);
+ struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
+
+ if (cattr->show)
+ ret = cattr->show(state, buf);
+
+ return ret;
+}
+
+static struct sysfs_ops cpuidle_state_sysfs_ops = {
+ .show = cpuidle_state_show,
+};
+
+static void cpuidle_state_sysfs_release(struct kobject *kobj)
+{
+ struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
+
+ complete(&state_obj->kobj_unregister);
+}
+
+static struct kobj_type ktype_state_cpuidle = {
+ .sysfs_ops = &cpuidle_state_sysfs_ops,
+ .default_attrs = cpuidle_state_default_attrs,
+ .release = cpuidle_state_sysfs_release,
+};
+
+static void inline cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
+{
+ kobject_unregister(&device->kobjs[i]->kobj);
+ wait_for_completion(&device->kobjs[i]->kobj_unregister);
+ kfree(device->kobjs[i]);
+ device->kobjs[i] = NULL;
+}
+
+/**
+ * cpuidle_add_driver_sysfs - adds driver-specific sysfs attributes
+ * @device: the target device
+ */
+int cpuidle_add_state_sysfs(struct cpuidle_device *device)
+{
+ int i, ret = -ENOMEM;
+ struct cpuidle_state_kobj *kobj;
+
+ /* state statistics */
+ for (i = 0; i < device->state_count; i++) {
+ kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
+ if (!kobj)
+ goto error_state;
+ kobj->state = &device->states[i];
+ init_completion(&kobj->kobj_unregister);
+
+ kobj->kobj.parent = &device->kobj;
+ kobj->kobj.ktype = &ktype_state_cpuidle;
+ kobject_set_name(&kobj->kobj, "state%d", i);
+ ret = kobject_register(&kobj->kobj);
+ if (ret) {
+ kfree(kobj);
+ goto error_state;
+ }
+ device->kobjs[i] = kobj;
+ }
+
+ return 0;
+
+error_state:
+ for (i = i - 1; i >= 0; i--)
+ cpuidle_free_state_kobj(device, i);
+ return ret;
+}
+
+/**
+ * cpuidle_remove_driver_sysfs - removes driver-specific sysfs attributes
+ * @device: the target device
+ */
+void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
+{
+ int i;
+
+ for (i = 0; i < device->state_count; i++)
+ cpuidle_free_state_kobj(device, i);
+}
+
+/**
+ * cpuidle_add_sysfs - creates a sysfs instance for the target device
+ * @sysdev: the target device
+ */
+int cpuidle_add_sysfs(struct sys_device *sysdev)
+{
+ int cpu = sysdev->id;
+ struct cpuidle_device *dev;
+
+ dev = per_cpu(cpuidle_devices, cpu);
+ dev->kobj.parent = &sysdev->kobj;
+ dev->kobj.ktype = &ktype_cpuidle;
+ kobject_set_name(&dev->kobj, "%s", "cpuidle");
+ return kobject_register(&dev->kobj);
+}
+
+/**
+ * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
+ * @sysdev: the target device
+ */
+void cpuidle_remove_sysfs(struct sys_device *sysdev)
+{
+ int cpu = sysdev->id;
+ struct cpuidle_device *dev;
+
+ dev = per_cpu(cpuidle_devices, cpu);
+ kobject_unregister(&dev->kobj);
+}
modify_acceptable_latency("ipw2100", INFINITE_LATENCY);
-#ifdef ACPI_CSTATE_LIMIT_DEFINED
- if (priv->config & CFG_C3_DISABLED) {
- IPW_DEBUG_INFO(": Resetting C3 transitions.\n");
- acpi_set_cstate_limit(priv->cstate_limit);
- priv->config &= ~CFG_C3_DISABLED;
- }
-#endif
-
/* We have to signal any supplicant if we are disassociating */
if (associated)
wireless_send_event(priv->net_dev, SIOCGIWAP, &wrqu, NULL);
/* RF_KILL is now enabled (else we wouldn't be here) */
priv->status |= STATUS_RF_KILL_HW;
-#ifdef ACPI_CSTATE_LIMIT_DEFINED
- if (priv->config & CFG_C3_DISABLED) {
- IPW_DEBUG_INFO(": Resetting C3 transitions.\n");
- acpi_set_cstate_limit(priv->cstate_limit);
- priv->config &= ~CFG_C3_DISABLED;
- }
-#endif
-
/* Make sure the RF Kill check timer is running */
priv->stop_rf_kill = 0;
cancel_delayed_work(&priv->rf_kill);
u32 match, reg;
int j;
#endif
-#ifdef ACPI_CSTATE_LIMIT_DEFINED
- int limit;
-#endif
IPW_DEBUG_INFO(": PCI latency error detected at 0x%04zX.\n",
i * sizeof(struct ipw2100_status));
-#ifdef ACPI_CSTATE_LIMIT_DEFINED
- IPW_DEBUG_INFO(": Disabling C3 transitions.\n");
- limit = acpi_get_cstate_limit();
- if (limit > 2) {
- priv->cstate_limit = limit;
- acpi_set_cstate_limit(2);
- priv->config |= CFG_C3_DISABLED;
- }
-#endif
-
#ifdef IPW2100_DEBUG_C3
/* Halt the fimrware so we can get a good image */
write_register(priv->net_dev, IPW_REG_RESET_REG,
#define CFG_ASSOCIATE (1<<6)
#define CFG_FIXED_RATE (1<<7)
#define CFG_ADHOC_CREATE (1<<8)
-#define CFG_C3_DISABLED (1<<9)
#define CFG_PASSIVE_SCAN (1<<10)
#ifdef CONFIG_IPW2100_MONITOR
#define CFG_CRC_CHECK (1<<11)
u8 bssid[ETH_ALEN];
u8 channel;
int last_mode;
- int cstate_limit;
unsigned long connect_start;
unsigned long last_reset;
#include <linux/kernel.h>
#include <linux/cpu.h>
+#include <linux/cpuidle.h>
#include <asm/acpi.h>
};
struct acpi_processor_power {
+ struct cpuidle_device dev;
struct acpi_processor_cx *state;
+ struct acpi_processor_cx *bm_state;
unsigned long bm_check_timestamp;
u32 default_state;
u32 bm_activity;
u8 bm_check:1;
u8 has_cst:1;
u8 power_setup_done:1;
+ u8 bm_rld_set:1;
};
struct acpi_processor {
struct acpi_device *device);
int acpi_processor_suspend(struct acpi_device * device, pm_message_t state);
int acpi_processor_resume(struct acpi_device * device);
+extern struct cpuidle_driver acpi_idle_driver;
/* in processor_thermal.c */
int acpi_processor_get_limit_info(struct acpi_processor *pr);
extern int acpi_blacklisted(void);
extern void acpi_bios_year(char *s);
-#define ACPI_CSTATE_LIMIT_DEFINED /* for driver builds */
-#ifdef CONFIG_ACPI
-
-/*
- * Set highest legal C-state
- * 0: C0 okay, but not C1
- * 1: C1 okay, but not C2
- * 2: C2 okay, but not C3 etc.
- */
-
-extern unsigned int max_cstate;
-
-static inline unsigned int acpi_get_cstate_limit(void)
-{
- return max_cstate;
-}
-static inline void acpi_set_cstate_limit(unsigned int new_limit)
-{
- max_cstate = new_limit;
- return;
-}
-#else
-static inline unsigned int acpi_get_cstate_limit(void) { return 0; }
-static inline void acpi_set_cstate_limit(unsigned int new_limit) { return; }
-#endif
-
#ifdef CONFIG_ACPI_NUMA
int acpi_get_pxm(acpi_handle handle);
int acpi_get_node(acpi_handle *handle);
--- /dev/null
+/*
+ * cpuidle.h - a generic framework for CPU idle power management
+ *
+ * (C) 2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ * Shaohua Li <shaohua.li@intel.com>
+ * Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#ifndef _LINUX_CPUIDLE_H
+#define _LINUX_CPUIDLE_H
+
+#include <linux/percpu.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+#include <linux/completion.h>
+
+#define CPUIDLE_STATE_MAX 8
+#define CPUIDLE_NAME_LEN 16
+
+struct cpuidle_device;
+
+
+/****************************
+ * CPUIDLE DEVICE INTERFACE *
+ ****************************/
+
+struct cpuidle_state {
+ char name[CPUIDLE_NAME_LEN];
+ void *driver_data;
+
+ unsigned int flags;
+ unsigned int exit_latency; /* in US */
+ unsigned int power_usage; /* in mW */
+ unsigned int target_residency; /* in US */
+
+ unsigned int usage;
+ unsigned int time; /* in US */
+
+ int (*enter) (struct cpuidle_device *dev,
+ struct cpuidle_state *state);
+};
+
+/* Idle State Flags */
+#define CPUIDLE_FLAG_TIME_VALID (0x01) /* is residency time measurable? */
+#define CPUIDLE_FLAG_CHECK_BM (0x02) /* BM activity will exit state */
+#define CPUIDLE_FLAG_SHALLOW (0x10) /* low latency, minimal savings */
+#define CPUIDLE_FLAG_BALANCED (0x20) /* medium latency, moderate savings */
+#define CPUIDLE_FLAG_DEEP (0x40) /* high latency, large savings */
+
+#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
+
+/**
+ * cpuidle_get_statedata - retrieves private driver state data
+ * @state: the state
+ */
+static inline void * cpuidle_get_statedata(struct cpuidle_state *state)
+{
+ return state->driver_data;
+}
+
+/**
+ * cpuidle_set_statedata - stores private driver state data
+ * @state: the state
+ * @data: the private data
+ */
+static inline void
+cpuidle_set_statedata(struct cpuidle_state *state, void *data)
+{
+ state->driver_data = data;
+}
+
+struct cpuidle_state_kobj {
+ struct cpuidle_state *state;
+ struct completion kobj_unregister;
+ struct kobject kobj;
+};
+
+struct cpuidle_device {
+ int enabled:1;
+ unsigned int cpu;
+
+ int last_residency;
+ int state_count;
+ struct cpuidle_state states[CPUIDLE_STATE_MAX];
+ struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
+ struct cpuidle_state *last_state;
+
+ struct list_head device_list;
+ struct kobject kobj;
+ struct completion kobj_unregister;
+ void *governor_data;
+};
+
+DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
+
+/**
+ * cpuidle_get_last_residency - retrieves the last state's residency time
+ * @dev: the target CPU
+ *
+ * NOTE: this value is invalid if CPUIDLE_FLAG_TIME_VALID isn't set
+ */
+static inline int cpuidle_get_last_residency(struct cpuidle_device *dev)
+{
+ return dev->last_residency;
+}
+
+
+/****************************
+ * CPUIDLE DRIVER INTERFACE *
+ ****************************/
+
+struct cpuidle_driver {
+ char name[CPUIDLE_NAME_LEN];
+ struct module *owner;
+};
+
+#ifdef CONFIG_CPU_IDLE
+
+extern int cpuidle_register_driver(struct cpuidle_driver *drv);
+extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
+extern int cpuidle_register_device(struct cpuidle_device *dev);
+extern void cpuidle_unregister_device(struct cpuidle_device *dev);
+
+extern void cpuidle_pause_and_lock(void);
+extern void cpuidle_resume_and_unlock(void);
+extern int cpuidle_enable_device(struct cpuidle_device *dev);
+extern void cpuidle_disable_device(struct cpuidle_device *dev);
+
+#else
+
+static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
+{return 0;}
+static inline void cpuidle_unregister_driver(struct cpuidle_driver *drv) { }
+static inline int cpuidle_register_device(struct cpuidle_device *dev)
+{return 0;}
+static inline void cpuidle_unregister_device(struct cpuidle_device *dev) { }
+
+static inline void cpuidle_pause_and_lock(void) { }
+static inline void cpuidle_resume_and_unlock(void) { }
+static inline int cpuidle_enable_device(struct cpuidle_device *dev)
+{return 0;}
+static inline void cpuidle_disable_device(struct cpuidle_device *dev) { }
+
+#endif
+
+/******************************
+ * CPUIDLE GOVERNOR INTERFACE *
+ ******************************/
+
+struct cpuidle_governor {
+ char name[CPUIDLE_NAME_LEN];
+ struct list_head governor_list;
+ unsigned int rating;
+
+ int (*enable) (struct cpuidle_device *dev);
+ void (*disable) (struct cpuidle_device *dev);
+
+ int (*select) (struct cpuidle_device *dev);
+ void (*reflect) (struct cpuidle_device *dev);
+
+ struct module *owner;
+};
+
+#ifdef CONFIG_CPU_IDLE
+
+extern int cpuidle_register_governor(struct cpuidle_governor *gov);
+extern void cpuidle_unregister_governor(struct cpuidle_governor *gov);
+
+#else
+
+static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
+{return 0;}
+static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { }
+
+#endif
+
+#endif /* _LINUX_CPUIDLE_H */
* @idle_sleeps: Number of idle calls, where the sched tick was stopped
* @idle_entrytime: Time when the idle call was entered
* @idle_sleeptime: Sum of the time slept in idle with sched tick stopped
+ * @sleep_length: Duration of the current idle sleep
*/
struct tick_sched {
struct hrtimer sched_timer;
unsigned long idle_sleeps;
ktime_t idle_entrytime;
ktime_t idle_sleeptime;
+ ktime_t sleep_length;
unsigned long last_jiffies;
unsigned long next_jiffies;
ktime_t idle_expires;
extern void tick_nohz_stop_sched_tick(void);
extern void tick_nohz_restart_sched_tick(void);
extern void tick_nohz_update_jiffies(void);
+extern ktime_t tick_nohz_get_sleep_length(void);
# else
static inline void tick_nohz_stop_sched_tick(void) { }
static inline void tick_nohz_restart_sched_tick(void) { }
static inline void tick_nohz_update_jiffies(void) { }
+static inline ktime_t tick_nohz_get_sleep_length(void)
+{
+ ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
+
+ return len;
+}
# endif /* !NO_HZ */
#endif
unsigned long seq, last_jiffies, next_jiffies, delta_jiffies, flags;
struct tick_sched *ts;
ktime_t last_update, expires, now, delta;
+ struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
int cpu;
local_irq_save(flags);
out:
ts->next_jiffies = next_jiffies;
ts->last_jiffies = last_jiffies;
+ ts->sleep_length = ktime_sub(dev->next_event, now);
end:
local_irq_restore(flags);
}
/**
+ * tick_nohz_get_sleep_length - return the length of the current sleep
+ *
+ * Called from power state control code with interrupts disabled
+ */
+ktime_t tick_nohz_get_sleep_length(void)
+{
+ struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+
+ return ts->sleep_length;
+}
+
+EXPORT_SYMBOL_GPL(tick_nohz_get_sleep_length);
+
+/**
* nohz_restart_sched_tick - restart the idle tick from the idle task
*
* Restart the idle tick when the CPU is woken up from idle
git://ftp.safe.ca / safe / jmp / linux-2.6 / commitdiff