diff options
| -rw-r--r-- | arch/x86/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/acpi/processor_idle.c | 4 | ||||
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 41 | ||||
| -rw-r--r-- | include/linux/cpuidle.h | 13 |
4 files changed, 57 insertions, 4 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index e6728bd61cc1..fd4265007053 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -105,6 +105,9 @@ config GENERIC_TIME_VSYSCALL bool default X86_64 +config ARCH_HAS_CPU_RELAX + def_bool y + config HAVE_SETUP_PER_CPU_AREA def_bool X86_64 diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index fea71597b40a..32488e6f76ab 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1628,7 +1628,7 @@ struct cpuidle_driver acpi_idle_driver = { */ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) { - int i, count = 0; + int i, count = CPUIDLE_DRIVER_STATE_START; struct acpi_processor_cx *cx; struct cpuidle_state *state; struct cpuidle_device *dev = &pr->power.dev; @@ -1687,6 +1687,8 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) } count++; + if (count == CPUIDLE_STATE_MAX) + break; } dev->state_count = count; diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 2a98d99cbd46..2c4b2d47973e 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -15,6 +15,7 @@ #include <linux/pm_qos_params.h> #include <linux/cpu.h> #include <linux/cpuidle.h> +#include <linux/ktime.h> #include "cpuidle.h" @@ -180,6 +181,44 @@ void cpuidle_disable_device(struct cpuidle_device *dev) EXPORT_SYMBOL_GPL(cpuidle_disable_device); +#ifdef CONFIG_ARCH_HAS_CPU_RELAX +static int poll_idle(struct cpuidle_device *dev, struct cpuidle_state *st) +{ + ktime_t t1, t2; + s64 diff; + int ret; + + t1 = ktime_get(); + local_irq_enable(); + while (!need_resched()) + cpu_relax(); + + t2 = ktime_get(); + diff = ktime_to_us(ktime_sub(t2, t1)); + if (diff > INT_MAX) + diff = INT_MAX; + + ret = (int) diff; + return ret; +} + +static void poll_idle_init(struct cpuidle_device *dev) +{ + struct cpuidle_state *state = &dev->states[0]; + + cpuidle_set_statedata(state, NULL); + + snprintf(state->name, CPUIDLE_NAME_LEN, "C0 (poll idle)"); + state->exit_latency = 0; + state->target_residency = 0; + state->power_usage = -1; + state->flags = CPUIDLE_FLAG_POLL | CPUIDLE_FLAG_TIME_VALID; + state->enter = poll_idle; +} +#else +static void poll_idle_init(struct cpuidle_device *dev) {} +#endif /* CONFIG_ARCH_HAS_CPU_RELAX */ + /** * cpuidle_register_device - registers a CPU's idle PM feature * @dev: the cpu @@ -198,6 +237,8 @@ int cpuidle_register_device(struct cpuidle_device *dev) mutex_lock(&cpuidle_lock); + poll_idle_init(dev); + per_cpu(cpuidle_devices, dev->cpu) = dev; list_add(&dev->device_list, &cpuidle_detected_devices); if ((ret = cpuidle_add_sysfs(sys_dev))) { diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index b0fd85ab9efb..385d45b616db 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -46,9 +46,10 @@ struct cpuidle_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_FLAG_POLL (0x10) /* no latency, no savings */ +#define CPUIDLE_FLAG_SHALLOW (0x20) /* low latency, minimal savings */ +#define CPUIDLE_FLAG_BALANCED (0x40) /* medium latency, moderate savings */ +#define CPUIDLE_FLAG_DEEP (0x80) /* high latency, large savings */ #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) @@ -178,4 +179,10 @@ static inline void cpuidle_unregister_governor(struct cpuidle_governor *gov) { } #endif +#ifdef CONFIG_ARCH_HAS_CPU_RELAX +#define CPUIDLE_DRIVER_STATE_START 1 +#else +#define CPUIDLE_DRIVER_STATE_START 0 +#endif + #endif /* _LINUX_CPUIDLE_H */ |