aboutsummaryrefslogtreecommitdiff
path: root/drivers/idle/intel_idle.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/idle/intel_idle.c')
-rw-r--r--drivers/idle/intel_idle.c67
1 files changed, 62 insertions, 5 deletions
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 56ac09d6c930..d14585b2e045 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -59,6 +59,8 @@
#include <linux/hrtimer.h> /* ktime_get_real() */
#include <trace/events/power.h>
#include <linux/sched.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
#include <asm/mwait.h>
#define INTEL_IDLE_VERSION "0.4"
@@ -73,6 +75,7 @@ static int max_cstate = MWAIT_MAX_NUM_CSTATES - 1;
static unsigned int mwait_substates;
+#define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF
/* Reliable LAPIC Timer States, bit 1 for C1 etc. */
static unsigned int lapic_timer_reliable_states = (1 << 1); /* Default to only C1 */
@@ -82,6 +85,14 @@ static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state);
static struct cpuidle_state *cpuidle_state_table;
/*
+ * Set this flag for states where the HW flushes the TLB for us
+ * and so we don't need cross-calls to keep it consistent.
+ * If this flag is set, SW flushes the TLB, so even if the
+ * HW doesn't do the flushing, this flag is safe to use.
+ */
+#define CPUIDLE_FLAG_TLB_FLUSHED 0x10000
+
+/*
* States are indexed by the cstate number,
* which is also the index into the MWAIT hint array.
* Thus C0 is a dummy.
@@ -122,7 +133,7 @@ static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = {
.driver_data = (void *) 0x00,
.flags = CPUIDLE_FLAG_TIME_VALID,
.exit_latency = 1,
- .target_residency = 4,
+ .target_residency = 1,
.enter = &intel_idle },
{ /* MWAIT C2 */
.name = "SNB-C3",
@@ -130,7 +141,7 @@ static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = {
.driver_data = (void *) 0x10,
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 80,
- .target_residency = 160,
+ .target_residency = 211,
.enter = &intel_idle },
{ /* MWAIT C3 */
.name = "SNB-C6",
@@ -138,7 +149,7 @@ static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = {
.driver_data = (void *) 0x20,
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 104,
- .target_residency = 208,
+ .target_residency = 345,
.enter = &intel_idle },
{ /* MWAIT C4 */
.name = "SNB-C7",
@@ -146,7 +157,7 @@ static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = {
.driver_data = (void *) 0x30,
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
.exit_latency = 109,
- .target_residency = 300,
+ .target_residency = 345,
.enter = &intel_idle },
};
@@ -243,6 +254,39 @@ static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state)
return usec_delta;
}
+static void __setup_broadcast_timer(void *arg)
+{
+ unsigned long reason = (unsigned long)arg;
+ int cpu = smp_processor_id();
+
+ reason = reason ?
+ CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
+
+ clockevents_notify(reason, &cpu);
+}
+
+static int __cpuinit setup_broadcast_cpuhp_notify(struct notifier_block *n,
+ unsigned long action, void *hcpu)
+{
+ int hotcpu = (unsigned long)hcpu;
+
+ switch (action & 0xf) {
+ case CPU_ONLINE:
+ smp_call_function_single(hotcpu, __setup_broadcast_timer,
+ (void *)true, 1);
+ break;
+ case CPU_DOWN_PREPARE:
+ smp_call_function_single(hotcpu, __setup_broadcast_timer,
+ (void *)false, 1);
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata setup_broadcast_notifier = {
+ .notifier_call = setup_broadcast_cpuhp_notify,
+};
+
/*
* intel_idle_probe()
*/
@@ -305,7 +349,11 @@ static int intel_idle_probe(void)
}
if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
- lapic_timer_reliable_states = 0xFFFFFFFF;
+ lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
+ else {
+ smp_call_function(__setup_broadcast_timer, (void *)true, 1);
+ register_cpu_notifier(&setup_broadcast_notifier);
+ }
pr_debug(PREFIX "v" INTEL_IDLE_VERSION
" model 0x%X\n", boot_cpu_data.x86_model);
@@ -403,6 +451,10 @@ static int __init intel_idle_init(void)
{
int retval;
+ /* Do not load intel_idle at all for now if idle= is passed */
+ if (boot_option_idle_override != IDLE_NO_OVERRIDE)
+ return -ENODEV;
+
retval = intel_idle_probe();
if (retval)
return retval;
@@ -428,6 +480,11 @@ static void __exit intel_idle_exit(void)
intel_idle_cpuidle_devices_uninit();
cpuidle_unregister_driver(&intel_idle_driver);
+ if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE) {
+ smp_call_function(__setup_broadcast_timer, (void *)false, 1);
+ unregister_cpu_notifier(&setup_broadcast_notifier);
+ }
+
return;
}