The patch titled
cpuidle take2: Hookup ACPI C-states driver with cpuidle
has been removed from the -mm tree. Its filename was
cpuidle-take2-hookup-acpi-c-states-driver-with-cpuidle.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: cpuidle take2: Hookup ACPI C-states driver with cpuidle
From: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Hookup ACPI C-states onto generic cpuidle infrastructure.
drivers/acpi/procesor_idle.c is now a ACPI C-states driver that registers as a
driver in cpuidle infrastructure and the policy part is removed from
drivers/acpi/processor_idle.c. We use governor in cpuidle instead.
Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Signed-off-by: Adam Belay <abelay@xxxxxxxxxx>
Cc: Dave Jones <davej@xxxxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/acpi/processor_core.c | 3
drivers/acpi/processor_idle.c | 498 +++++++++++++++++++++-----------
include/acpi/processor.h | 2
3 files changed, 337 insertions(+), 166 deletions(-)
diff -puN drivers/acpi/processor_core.c~cpuidle-take2-hookup-acpi-c-states-driver-with-cpuidle drivers/acpi/processor_core.c
--- a/drivers/acpi/processor_core.c~cpuidle-take2-hookup-acpi-c-states-driver-with-cpuidle
+++ a/drivers/acpi/processor_core.c
@@ -44,6 +44,7 @@
#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>
@@ -1028,11 +1029,13 @@ static int __init acpi_processor_init(vo
acpi_processor_ppc_init();
+ cpuidle_register_driver(&acpi_idle_driver);
return 0;
}
static void __exit acpi_processor_exit(void)
{
+ cpuidle_unregister_driver(&acpi_idle_driver);
acpi_processor_ppc_exit();
diff -puN drivers/acpi/processor_idle.c~cpuidle-take2-hookup-acpi-c-states-driver-with-cpuidle drivers/acpi/processor_idle.c
--- a/drivers/acpi/processor_idle.c~cpuidle-take2-hookup-acpi-c-states-driver-with-cpuidle
+++ a/drivers/acpi/processor_idle.c
@@ -40,6 +40,7 @@
#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
@@ -70,25 +71,15 @@
#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 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;
+#define PM_TIMER_TICKS_TO_US(p) (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
+#define C2_OVERHEAD 1 /* 1us */
+#define C3_OVERHEAD 1 /* 1us */
+
module_param(max_cstate, uint, 0644);
static unsigned int nocst __read_mostly;
module_param(nocst, uint, 0000);
-/*
- * 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);
/* --------------------------------------------------------------------------
Power Management
-------------------------------------------------------------------------- */
@@ -174,88 +165,6 @@ static struct dmi_system_id __cpuinitdat
{},
};
-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 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 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();
- current_thread_info()->status |= TS_POLLING;
-}
-
-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->space_id == 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);
- }
-}
-
#ifdef ARCH_APICTIMER_STOPS_ON_C3
/*
@@ -917,7 +826,7 @@ static void acpi_processor_power_verify_
* Normalize the C2 latency to expidite policy
*/
cx->valid = 1;
- cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
+ cx->latency_ticks = cx->latency;
return;
}
@@ -991,7 +900,7 @@ static void acpi_processor_power_verify_
* use this in our C3 policy
*/
cx->valid = 1;
- cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
+ cx->latency_ticks = cx->latency;
return;
}
@@ -1057,18 +966,6 @@ static int acpi_processor_get_power_info
pr->power.count = acpi_processor_power_verify(pr);
/*
- * 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;
-
- /*
* if one state of type C2 or C3 is available, mark this
* CPU as being "idle manageable"
*/
@@ -1085,9 +982,6 @@ static int acpi_processor_get_power_info
int acpi_processor_cst_has_changed(struct acpi_processor *pr)
{
- int result = 0;
-
-
if (!pr)
return -EINVAL;
@@ -1098,16 +992,8 @@ int acpi_processor_cst_has_changed(struc
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;
+ acpi_processor_get_power_info(pr);
+ return cpuidle_force_redetect(&per_cpu(cpuidle_devices, pr->id));
}
/* proc interface */
@@ -1193,30 +1079,6 @@ static const struct file_operations acpi
.release = single_release,
};
-#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
-
int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
struct acpi_device *device)
{
@@ -1233,9 +1095,6 @@ int __cpuinit acpi_processor_power_init(
"ACPI: processor limited to max C-state %d\n",
max_cstate);
first_run++;
-#ifdef CONFIG_SMP
- register_latency_notifier(&acpi_processor_latency_notifier);
-#endif
}
if (!pr)
@@ -1252,6 +1111,7 @@ int __cpuinit acpi_processor_power_init(
acpi_processor_get_power_info(pr);
+
/*
* Install the idle handler if processor power management is supported.
* Note that we use previously set idle handler will be used on
@@ -1264,11 +1124,6 @@ int __cpuinit acpi_processor_power_init(
printk(" C%d[C%d]", i,
pr->power.states[i].type);
printk(")\n");
-
- if (pr->id == 0) {
- pm_idle_save = pm_idle;
- pm_idle = acpi_processor_idle;
- }
}
/* 'power' [R] */
@@ -1296,21 +1151,332 @@ int acpi_processor_power_exit(struct acp
if (acpi_device_dir(device))
remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
acpi_device_dir(device));
+ return 0;
+}
- /* Unregister the idle handler when processor #0 is removed. */
- if (pr->id == 0) {
- pm_idle = pm_idle_save;
+/**
+ * ticks_elapsed - a helper function that determines how many ticks (in US)
+ * have elapsed between two PM Timer timestamps
+ * @t1: the start time
+ * @t2: the end time
+ */
+static inline u32 ticks_elapsed(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);
+}
- /*
- * 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
- unregister_latency_notifier(&acpi_processor_latency_notifier);
+/**
+ * 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_c2 - enters an ACPI C2 state-type
+ * @dev: the target CPU
+ * @state: the state data
+ */
+static int acpi_idle_enter_c2(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 (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;
+ }
+
+ 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);
+
+#ifdef CONFIG_GENERIC_TIME
+ /* TSC halts in C2, so notify users */
+ mark_tsc_unstable("possible TSC halt in C2");
#endif
+
+ local_irq_enable();
+ current_thread_info()->status |= TS_POLLING;
+
+ cx->usage++;
+
+ acpi_state_timer_broadcast(pr, cx, 0);
+ return ticks_elapsed(t1, t2);
+}
+
+static int c3_cpu_count;
+static DEFINE_SPINLOCK(c3_lock);
+
+/**
+ * acpi_idle_enter_c3 - enters an ACPI C3 state-type
+ * @dev: the target CPU
+ * @state: the state data
+ *
+ * Similar to C2 entry, except special bus master handling is needed.
+ */
+static int acpi_idle_enter_c3(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 (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;
}
+ /* disable bus master */
+ if (pr->flags.bm_check) {
+ spin_lock(&c3_lock);
+ c3_cpu_count++;
+ if (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);
+ }
+ spin_unlock(&c3_lock);
+ } else {
+ /* SMP with no shared cache... Invalidate cache */
+ ACPI_FLUSH_CPU_CACHE();
+ }
+
+ /* Get start time (ticks) */
+ 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 (pr->flags.bm_check) {
+ spin_lock(&c3_lock);
+ /* 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);
+ }
+
+#ifdef CONFIG_GENERIC_TIME
+ /* TSC halts in C3, so notify users */
+ mark_tsc_unstable("TSC halts in C3");
+#endif
+
+ local_irq_enable();
+ current_thread_info()->status |= TS_POLLING;
+
+ cx->usage++;
+
+ acpi_state_timer_broadcast(pr, cx, 0);
+ return ticks_elapsed(t1, t2);
+}
+
+/**
+ * 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_init - attaches the driver to a CPU
+ * @dev: the CPU
+ */
+static int acpi_idle_init(struct cpuidle_device *dev)
+{
+ int cpu = dev->cpu;
+ int i, count = 0;
+ struct acpi_processor_cx *cx;
+ struct cpuidle_state *state;
+
+ struct acpi_processor *pr = processors[cpu];
+
+ if (!pr->flags.power_setup_done)
+ return -EINVAL;
+
+ if (pr->flags.power == 0) {
+ return -EINVAL;
+ }
+
+ for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; 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);
+
+ 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_c2;
+ break;
+
+ case ACPI_STATE_C3:
+ state->flags |= CPUIDLE_FLAG_DEEP;
+ state->flags |= CPUIDLE_FLAG_TIME_VALID;
+ state->flags |= CPUIDLE_FLAG_CHECK_BM;
+ state->enter = acpi_idle_enter_c3;
+ break;
+ }
+
+ count++;
+ }
+
+ if (!count)
+ return -EINVAL;
+
+ dev->state_count = count;
return 0;
}
+
+struct cpuidle_driver acpi_idle_driver = {
+ .name = "acpi_idle",
+ .init = acpi_idle_init,
+ .redetect = acpi_idle_init,
+ .bm_check = acpi_idle_bm_check,
+ .owner = THIS_MODULE,
+};
diff -puN include/acpi/processor.h~cpuidle-take2-hookup-acpi-c-states-driver-with-cpuidle include/acpi/processor.h
--- a/include/acpi/processor.h~cpuidle-take2-hookup-acpi-c-states-driver-with-cpuidle
+++ a/include/acpi/processor.h
@@ -161,6 +161,7 @@ struct acpi_processor_flags {
u8 bm_check:1;
u8 has_cst:1;
u8 power_setup_done:1;
+ u8 bm_rld_set:1;
};
struct acpi_processor {
@@ -275,6 +276,7 @@ int acpi_processor_power_init(struct acp
int acpi_processor_cst_has_changed(struct acpi_processor *pr);
int acpi_processor_power_exit(struct acpi_processor *pr,
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);
_
Patches currently in -mm which might be from venkatesh.pallipadi@xxxxxxxxx are
git-acpi.patch
workqueue-fix-freezeable-workqueues-implementation.patch
workqueue-fix-flush_workqueue-vs-cpu_dead-race.patch
workqueue-dont-clear-cwq-thread-until-it-exits.patch
workqueue-dont-migrate-pending-works-from-the-dead-cpu.patch
-
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