From 46bcfad7a819bd17ac4e831b04405152d59784ab Mon Sep 17 00:00:00 2001 From: Deepthi Dharwar Date: Fri, 28 Oct 2011 16:20:42 +0530 Subject: cpuidle: Single/Global registration of idle states This patch makes the cpuidle_states structure global (single copy) instead of per-cpu. The statistics needed on per-cpu basis by the governor are kept per-cpu. This simplifies the cpuidle subsystem as state registration is done by single cpu only. Having single copy of cpuidle_states saves memory. Rare case of asymmetric C-states can be handled within the cpuidle driver and architectures such as POWER do not have asymmetric C-states. Having single/global registration of all the idle states, dynamic C-state transitions on x86 are handled by the boot cpu. Here, the boot cpu would disable all the devices, re-populate the states and later enable all the devices, irrespective of the cpu that would receive the notification first. Reference: https://lkml.org/lkml/2011/4/25/83 Signed-off-by: Deepthi Dharwar Signed-off-by: Trinabh Gupta Tested-by: Jean Pihet Reviewed-by: Kevin Hilman Acked-by: Arjan van de Ven Acked-by: Kevin Hilman Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 191 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 166 insertions(+), 25 deletions(-) (limited to 'drivers/acpi/processor_idle.c') diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index b98c75285690..24fe3afa7119 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -741,11 +741,13 @@ static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx) /** * acpi_idle_enter_c1 - enters an ACPI C1 state-type * @dev: the target CPU + * @drv: cpuidle driver containing cpuidle state info * @index: index of target state * * This is equivalent to the HALT instruction. */ -static int acpi_idle_enter_c1(struct cpuidle_device *dev, int index) +static int acpi_idle_enter_c1(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) { ktime_t kt1, kt2; s64 idle_time; @@ -787,9 +789,11 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev, int index) /** * acpi_idle_enter_simple - enters an ACPI state without BM handling * @dev: the target CPU + * @drv: cpuidle driver with cpuidle state information * @index: the index of suggested state */ -static int acpi_idle_enter_simple(struct cpuidle_device *dev, int index) +static int acpi_idle_enter_simple(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) { struct acpi_processor *pr; struct cpuidle_state_usage *state_usage = &dev->states_usage[index]; @@ -869,11 +873,13 @@ static DEFINE_SPINLOCK(c3_lock); /** * acpi_idle_enter_bm - enters C3 with proper BM handling * @dev: the target CPU + * @drv: cpuidle driver containing state data * @index: the index of suggested state * * If BM is detected, the deepest non-C3 idle state is entered instead. */ -static int acpi_idle_enter_bm(struct cpuidle_device *dev, int index) +static int acpi_idle_enter_bm(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) { struct acpi_processor *pr; struct cpuidle_state_usage *state_usage = &dev->states_usage[index]; @@ -896,9 +902,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, int index) } if (!cx->bm_sts_skip && acpi_idle_bm_check()) { - if (dev->safe_state_index >= 0) { - return dev->states[dev->safe_state_index].enter(dev, - dev->safe_state_index); + if (drv->safe_state_index >= 0) { + return drv->states[drv->safe_state_index].enter(dev, + drv, drv->safe_state_index); } else { local_irq_disable(); acpi_safe_halt(); @@ -993,14 +999,15 @@ struct cpuidle_driver acpi_idle_driver = { }; /** - * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE + * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE + * device i.e. per-cpu data + * * @pr: the ACPI processor */ -static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) +static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr) { int i, count = CPUIDLE_DRIVER_STATE_START; struct acpi_processor_cx *cx; - struct cpuidle_state *state; struct cpuidle_state_usage *state_usage; struct cpuidle_device *dev = &pr->power.dev; @@ -1012,18 +1019,12 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) } dev->cpu = pr->id; - dev->safe_state_index = -1; - for (i = 0; i < CPUIDLE_STATE_MAX; i++) { - dev->states[i].name[0] = '\0'; - dev->states[i].desc[0] = '\0'; - } if (max_cstate == 0) max_cstate = 1; for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { cx = &pr->power.states[i]; - state = &dev->states[count]; state_usage = &dev->states_usage[count]; if (!cx->valid) @@ -1035,8 +1036,64 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) continue; #endif + cpuidle_set_statedata(state_usage, cx); + count++; + if (count == CPUIDLE_STATE_MAX) + break; + } + + dev->state_count = count; + + if (!count) + return -EINVAL; + + return 0; +} + +/** + * acpi_processor_setup_cpuidle states- prepares and configures cpuidle + * global state data i.e. idle routines + * + * @pr: the ACPI processor + */ +static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) +{ + int i, count = CPUIDLE_DRIVER_STATE_START; + struct acpi_processor_cx *cx; + struct cpuidle_state *state; + struct cpuidle_driver *drv = &acpi_idle_driver; + + if (!pr->flags.power_setup_done) + return -EINVAL; + + if (pr->flags.power == 0) + return -EINVAL; + + drv->safe_state_index = -1; + for (i = 0; i < CPUIDLE_STATE_MAX; i++) { + drv->states[i].name[0] = '\0'; + drv->states[i].desc[0] = '\0'; + } + + if (max_cstate == 0) + max_cstate = 1; + + for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) { + cx = &pr->power.states[i]; + + 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 + + state = &drv->states[count]; snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); state->exit_latency = cx->latency; @@ -1049,13 +1106,13 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) state->flags |= CPUIDLE_FLAG_TIME_VALID; state->enter = acpi_idle_enter_c1; - dev->safe_state_index = count; + drv->safe_state_index = count; break; case ACPI_STATE_C2: state->flags |= CPUIDLE_FLAG_TIME_VALID; state->enter = acpi_idle_enter_simple; - dev->safe_state_index = count; + drv->safe_state_index = count; break; case ACPI_STATE_C3: @@ -1071,7 +1128,7 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) break; } - dev->state_count = count; + drv->state_count = count; if (!count) return -EINVAL; @@ -1079,7 +1136,7 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr) return 0; } -int acpi_processor_cst_has_changed(struct acpi_processor *pr) +int acpi_processor_hotplug(struct acpi_processor *pr) { int ret = 0; @@ -1100,7 +1157,7 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr) cpuidle_disable_device(&pr->power.dev); acpi_processor_get_power_info(pr); if (pr->flags.power) { - acpi_processor_setup_cpuidle(pr); + acpi_processor_setup_cpuidle_cx(pr); ret = cpuidle_enable_device(&pr->power.dev); } cpuidle_resume_and_unlock(); @@ -1108,10 +1165,72 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr) return ret; } +int acpi_processor_cst_has_changed(struct acpi_processor *pr) +{ + int cpu; + struct acpi_processor *_pr; + + if (disabled_by_idle_boot_param()) + return 0; + + if (!pr) + return -EINVAL; + + if (nocst) + return -ENODEV; + + if (!pr->flags.power_setup_done) + return -ENODEV; + + /* + * FIXME: Design the ACPI notification to make it once per + * system instead of once per-cpu. This condition is a hack + * to make the code that updates C-States be called once. + */ + + if (smp_processor_id() == 0 && + cpuidle_get_driver() == &acpi_idle_driver) { + + cpuidle_pause_and_lock(); + /* Protect against cpu-hotplug */ + get_online_cpus(); + + /* Disable all cpuidle devices */ + for_each_online_cpu(cpu) { + _pr = per_cpu(processors, cpu); + if (!_pr || !_pr->flags.power_setup_done) + continue; + cpuidle_disable_device(&_pr->power.dev); + } + + /* Populate Updated C-state information */ + acpi_processor_setup_cpuidle_states(pr); + + /* Enable all cpuidle devices */ + for_each_online_cpu(cpu) { + _pr = per_cpu(processors, cpu); + if (!_pr || !_pr->flags.power_setup_done) + continue; + acpi_processor_get_power_info(_pr); + if (_pr->flags.power) { + acpi_processor_setup_cpuidle_cx(_pr); + cpuidle_enable_device(&_pr->power.dev); + } + } + put_online_cpus(); + cpuidle_resume_and_unlock(); + } + + return 0; +} + +static int acpi_processor_registered; + int __cpuinit acpi_processor_power_init(struct acpi_processor *pr, struct acpi_device *device) { acpi_status status = 0; + int retval; static int first_run; if (disabled_by_idle_boot_param()) @@ -1148,9 +1267,26 @@ int __cpuinit acpi_processor_power_init(struct acpi_processor *pr, * platforms that only support C1. */ if (pr->flags.power) { - acpi_processor_setup_cpuidle(pr); - if (cpuidle_register_device(&pr->power.dev)) - return -EIO; + /* Register acpi_idle_driver if not already registered */ + if (!acpi_processor_registered) { + acpi_processor_setup_cpuidle_states(pr); + retval = cpuidle_register_driver(&acpi_idle_driver); + if (retval) + return retval; + printk(KERN_DEBUG "ACPI: %s registered with cpuidle\n", + acpi_idle_driver.name); + } + /* Register per-cpu cpuidle_device. Cpuidle driver + * must already be registered before registering device + */ + acpi_processor_setup_cpuidle_cx(pr); + retval = cpuidle_register_device(&pr->power.dev); + if (retval) { + if (acpi_processor_registered == 0) + cpuidle_unregister_driver(&acpi_idle_driver); + return retval; + } + acpi_processor_registered++; } return 0; } @@ -1161,8 +1297,13 @@ int acpi_processor_power_exit(struct acpi_processor *pr, if (disabled_by_idle_boot_param()) return 0; - cpuidle_unregister_device(&pr->power.dev); - pr->flags.power_setup_done = 0; + if (pr->flags.power) { + cpuidle_unregister_device(&pr->power.dev); + acpi_processor_registered--; + if (acpi_processor_registered == 0) + cpuidle_unregister_driver(&acpi_idle_driver); + } + pr->flags.power_setup_done = 0; return 0; } -- cgit v1.2.3