diff options
author | Sudeep Holla <Sudeep.Holla@arm.com> | 2016-07-21 19:18:07 +0300 |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-07-22 00:25:58 +0300 |
commit | a36a7fecfe6071732075ad5aa31196adce13181b (patch) | |
tree | e3d88c1b278e013b10bd1280dc0257d5b23cba3c /drivers/acpi | |
parent | 35ae713355868aa493edbfbabf615473473215cc (diff) | |
download | linux-a36a7fecfe6071732075ad5aa31196adce13181b.tar.xz |
ACPI / processor_idle: Add support for Low Power Idle(LPI) states
ACPI 6.0 introduced an optional object _LPI that provides an alternate
method to describe Low Power Idle states. It defines the local power
states for each node in a hierarchical processor topology. The OSPM can
use _LPI object to select a local power state for each level of processor
hierarchy in the system. They used to produce a composite power state
request that is presented to the platform by the OSPM.
Since multiple processors affect the idle state for any non-leaf hierarchy
node, coordination of idle state requests between the processors is
required. ACPI supports two different coordination schemes: Platform
coordinated and OS initiated.
This patch adds initial support for Platform coordination scheme of LPI.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r-- | drivers/acpi/bus.c | 14 | ||||
-rw-r--r-- | drivers/acpi/processor_driver.c | 2 | ||||
-rw-r--r-- | drivers/acpi/processor_idle.c | 466 |
3 files changed, 425 insertions, 57 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index 262ca31b86d9..80ebb05e387c 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -302,6 +302,14 @@ out_kfree: EXPORT_SYMBOL(acpi_run_osc); bool osc_sb_apei_support_acked; + +/* + * ACPI 6.0 Section 8.4.4.2 Idle State Coordination + * OSPM supports platform coordinated low power idle(LPI) states + */ +bool osc_pc_lpi_support_confirmed; +EXPORT_SYMBOL_GPL(osc_pc_lpi_support_confirmed); + static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48"; static void acpi_bus_osc_support(void) { @@ -322,6 +330,7 @@ static void acpi_bus_osc_support(void) capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PPC_OST_SUPPORT; capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT; + capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PCLPI_SUPPORT; if (!ghes_disable) capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT; @@ -329,9 +338,12 @@ static void acpi_bus_osc_support(void) return; if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) { u32 *capbuf_ret = context.ret.pointer; - if (context.ret.length > OSC_SUPPORT_DWORD) + if (context.ret.length > OSC_SUPPORT_DWORD) { osc_sb_apei_support_acked = capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT; + osc_pc_lpi_support_confirmed = + capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT; + } kfree(context.ret.pointer); } /* do we need to check other returned cap? Sounds no */ diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index d2fa8cb82d2b..0ca14ac7bb28 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -90,7 +90,7 @@ static void acpi_processor_notify(acpi_handle handle, u32 event, void *data) pr->performance_platform_limit); break; case ACPI_PROCESSOR_NOTIFY_POWER: - acpi_processor_cst_has_changed(pr); + acpi_processor_power_state_has_changed(pr); acpi_bus_generate_netlink_event(device->pnp.device_class, dev_name(&device->dev), event, 0); break; diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index ca0de35d1c3a..cea52528aa18 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -303,7 +303,6 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr) struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; union acpi_object *cst; - if (nocst) return -ENODEV; @@ -576,7 +575,7 @@ static int acpi_processor_power_verify(struct acpi_processor *pr) return (working); } -static int acpi_processor_get_power_info(struct acpi_processor *pr) +static int acpi_processor_get_cstate_info(struct acpi_processor *pr) { unsigned int i; int result; @@ -810,31 +809,12 @@ static void acpi_idle_enter_freeze(struct cpuidle_device *dev, acpi_idle_do_entry(cx); } -/** - * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE - * device i.e. per-cpu data - * - * @pr: the ACPI processor - * @dev : the cpuidle device - */ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, struct cpuidle_device *dev) { int i, count = CPUIDLE_DRIVER_STATE_START; struct acpi_processor_cx *cx; - if (!pr->flags.power_setup_done) - return -EINVAL; - - if (pr->flags.power == 0) { - return -EINVAL; - } - - if (!dev) - return -EINVAL; - - dev->cpu = pr->id; - if (max_cstate == 0) max_cstate = 1; @@ -857,31 +837,13 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, 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) +static int acpi_processor_setup_cstates(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 = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) { - drv->states[i].name[0] = '\0'; - drv->states[i].desc[0] = '\0'; - } - if (max_cstate == 0) max_cstate = 1; @@ -893,7 +855,7 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) state = &drv->states[count]; snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i); - strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); + strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN); state->exit_latency = cx->latency; state->target_residency = cx->latency * latency_factor; state->enter = acpi_idle_enter; @@ -952,7 +914,7 @@ static inline void acpi_processor_cstate_first_run_checks(void) static inline int disabled_by_idle_boot_param(void) { return 0; } static inline void acpi_processor_cstate_first_run_checks(void) { } -static int acpi_processor_get_power_info(struct acpi_processor *pr) +static int acpi_processor_get_cstate_info(struct acpi_processor *pr) { return -ENODEV; } @@ -963,13 +925,413 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, return -EINVAL; } -static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) +static int acpi_processor_setup_cstates(struct acpi_processor *pr) { return -EINVAL; } #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */ +struct acpi_lpi_states_array { + unsigned int size; + unsigned int composite_states_size; + struct acpi_lpi_state *entries; + struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER]; +}; + +static int obj_get_integer(union acpi_object *obj, u32 *value) +{ + if (obj->type != ACPI_TYPE_INTEGER) + return -EINVAL; + + *value = obj->integer.value; + return 0; +} + +static int acpi_processor_evaluate_lpi(acpi_handle handle, + struct acpi_lpi_states_array *info) +{ + acpi_status status; + int ret = 0; + int pkg_count, state_idx = 1, loop; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + union acpi_object *lpi_data; + struct acpi_lpi_state *lpi_state; + + status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer); + if (ACPI_FAILURE(status)) { + ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n")); + return -ENODEV; + } + + lpi_data = buffer.pointer; + + /* There must be at least 4 elements = 3 elements + 1 package */ + if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE || + lpi_data->package.count < 4) { + pr_debug("not enough elements in _LPI\n"); + ret = -ENODATA; + goto end; + } + + pkg_count = lpi_data->package.elements[2].integer.value; + + /* Validate number of power states. */ + if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) { + pr_debug("count given by _LPI is not valid\n"); + ret = -ENODATA; + goto end; + } + + lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL); + if (!lpi_state) { + ret = -ENOMEM; + goto end; + } + + info->size = pkg_count; + info->entries = lpi_state; + + /* LPI States start at index 3 */ + for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) { + union acpi_object *element, *pkg_elem, *obj; + + element = &lpi_data->package.elements[loop]; + if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7) + continue; + + pkg_elem = element->package.elements; + + obj = pkg_elem + 6; + if (obj->type == ACPI_TYPE_BUFFER) { + struct acpi_power_register *reg; + + reg = (struct acpi_power_register *)obj->buffer.pointer; + if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO && + reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) + continue; + + lpi_state->address = reg->address; + lpi_state->entry_method = + reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ? + ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO; + } else if (obj->type == ACPI_TYPE_INTEGER) { + lpi_state->entry_method = ACPI_CSTATE_INTEGER; + lpi_state->address = obj->integer.value; + } else { + continue; + } + + /* elements[7,8] skipped for now i.e. Residency/Usage counter*/ + + obj = pkg_elem + 9; + if (obj->type == ACPI_TYPE_STRING) + strlcpy(lpi_state->desc, obj->string.pointer, + ACPI_CX_DESC_LEN); + + lpi_state->index = state_idx; + if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) { + pr_debug("No min. residency found, assuming 10 us\n"); + lpi_state->min_residency = 10; + } + + if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) { + pr_debug("No wakeup residency found, assuming 10 us\n"); + lpi_state->wake_latency = 10; + } + + if (obj_get_integer(pkg_elem + 2, &lpi_state->flags)) + lpi_state->flags = 0; + + if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags)) + lpi_state->arch_flags = 0; + + if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq)) + lpi_state->res_cnt_freq = 1; + + if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state)) + lpi_state->enable_parent_state = 0; + } + + acpi_handle_debug(handle, "Found %d power states\n", state_idx); +end: + kfree(buffer.pointer); + return ret; +} + +/* + * flat_state_cnt - the number of composite LPI states after the process of flattening + */ +static int flat_state_cnt; + +/** + * combine_lpi_states - combine local and parent LPI states to form a composite LPI state + * + * @local: local LPI state + * @parent: parent LPI state + * @result: composite LPI state + */ +static bool combine_lpi_states(struct acpi_lpi_state *local, + struct acpi_lpi_state *parent, + struct acpi_lpi_state *result) +{ + if (parent->entry_method == ACPI_CSTATE_INTEGER) { + if (!parent->address) /* 0 means autopromotable */ + return false; + result->address = local->address + parent->address; + } else { + result->address = parent->address; + } + + result->min_residency = max(local->min_residency, parent->min_residency); + result->wake_latency = local->wake_latency + parent->wake_latency; + result->enable_parent_state = parent->enable_parent_state; + result->entry_method = local->entry_method; + + result->flags = parent->flags; + result->arch_flags = parent->arch_flags; + result->index = parent->index; + + strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN); + strlcat(result->desc, "+", ACPI_CX_DESC_LEN); + strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN); + return true; +} + +#define ACPI_LPI_STATE_FLAGS_ENABLED BIT(0) + +static void stash_composite_state(struct acpi_lpi_states_array *curr_level, + struct acpi_lpi_state *t) +{ + curr_level->composite_states[curr_level->composite_states_size++] = t; +} + +static int flatten_lpi_states(struct acpi_processor *pr, + struct acpi_lpi_states_array *curr_level, + struct acpi_lpi_states_array *prev_level) +{ + int i, j, state_count = curr_level->size; + struct acpi_lpi_state *p, *t = curr_level->entries; + + curr_level->composite_states_size = 0; + for (j = 0; j < state_count; j++, t++) { + struct acpi_lpi_state *flpi; + + if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED)) + continue; + + if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) { + pr_warn("Limiting number of LPI states to max (%d)\n", + ACPI_PROCESSOR_MAX_POWER); + pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n"); + break; + } + + flpi = &pr->power.lpi_states[flat_state_cnt]; + + if (!prev_level) { /* leaf/processor node */ + memcpy(flpi, t, sizeof(*t)); + stash_composite_state(curr_level, flpi); + flat_state_cnt++; + continue; + } + + for (i = 0; i < prev_level->composite_states_size; i++) { + p = prev_level->composite_states[i]; + if (t->index <= p->enable_parent_state && + combine_lpi_states(p, t, flpi)) { + stash_composite_state(curr_level, flpi); + flat_state_cnt++; + flpi++; + } + } + } + + kfree(curr_level->entries); + return 0; +} + +static int acpi_processor_get_lpi_info(struct acpi_processor *pr) +{ + int ret, i; + acpi_status status; + acpi_handle handle = pr->handle, pr_ahandle; + struct acpi_device *d = NULL; + struct acpi_lpi_states_array info[2], *tmp, *prev, *curr; + + if (!osc_pc_lpi_support_confirmed) + return -EOPNOTSUPP; + + if (!acpi_has_method(handle, "_LPI")) + return -EINVAL; + + flat_state_cnt = 0; + prev = &info[0]; + curr = &info[1]; + handle = pr->handle; + ret = acpi_processor_evaluate_lpi(handle, prev); + if (ret) + return ret; + flatten_lpi_states(pr, prev, NULL); + + status = acpi_get_parent(handle, &pr_ahandle); + while (ACPI_SUCCESS(status)) { + acpi_bus_get_device(pr_ahandle, &d); + handle = pr_ahandle; + + if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID)) + break; + + /* can be optional ? */ + if (!acpi_has_method(handle, "_LPI")) + break; + + ret = acpi_processor_evaluate_lpi(handle, curr); + if (ret) + break; + + /* flatten all the LPI states in this level of hierarchy */ + flatten_lpi_states(pr, curr, prev); + + tmp = prev, prev = curr, curr = tmp; + + status = acpi_get_parent(handle, &pr_ahandle); + } + + pr->power.count = flat_state_cnt; + /* reset the index after flattening */ + for (i = 0; i < pr->power.count; i++) + pr->power.lpi_states[i].index = i; + + /* Tell driver that _LPI is supported. */ + pr->flags.has_lpi = 1; + pr->flags.power = 1; + + return 0; +} + +int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu) +{ + return -ENODEV; +} + +int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi) +{ + return -ENODEV; +} + +/** + * acpi_idle_lpi_enter - enters an ACPI any LPI state + * @dev: the target CPU + * @drv: cpuidle driver containing cpuidle state info + * @index: index of target state + * + * Return: 0 for success or negative value for error + */ +static int acpi_idle_lpi_enter(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) +{ + struct acpi_processor *pr; + struct acpi_lpi_state *lpi; + + pr = __this_cpu_read(processors); + + if (unlikely(!pr)) + return -EINVAL; + + lpi = &pr->power.lpi_states[index]; + if (lpi->entry_method == ACPI_CSTATE_FFH) + return acpi_processor_ffh_lpi_enter(lpi); + + return -EINVAL; +} + +static int acpi_processor_setup_lpi_states(struct acpi_processor *pr) +{ + int i; + struct acpi_lpi_state *lpi; + struct cpuidle_state *state; + struct cpuidle_driver *drv = &acpi_idle_driver; + + if (!pr->flags.has_lpi) + return -EOPNOTSUPP; + + for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) { + lpi = &pr->power.lpi_states[i]; + + state = &drv->states[i]; + snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i); + strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN); + state->exit_latency = lpi->wake_latency; + state->target_residency = lpi->min_residency; + if (lpi->arch_flags) + state->flags |= CPUIDLE_FLAG_TIMER_STOP; + state->enter = acpi_idle_lpi_enter; + drv->safe_state_index = i; + } + + drv->state_count = i; + + 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; + struct cpuidle_driver *drv = &acpi_idle_driver; + + if (!pr->flags.power_setup_done || !pr->flags.power) + return -EINVAL; + + drv->safe_state_index = -1; + for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) { + drv->states[i].name[0] = '\0'; + drv->states[i].desc[0] = '\0'; + } + + if (pr->flags.has_lpi) + return acpi_processor_setup_lpi_states(pr); + + return acpi_processor_setup_cstates(pr); +} + +/** + * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE + * device i.e. per-cpu data + * + * @pr: the ACPI processor + * @dev : the cpuidle device + */ +static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr, + struct cpuidle_device *dev) +{ + if (!pr->flags.power_setup_done || !pr->flags.power || !dev) + return -EINVAL; + + dev->cpu = pr->id; + if (pr->flags.has_lpi) + return acpi_processor_ffh_lpi_probe(pr->id); + + return acpi_processor_setup_cpuidle_cx(pr, dev); +} + +static int acpi_processor_get_power_info(struct acpi_processor *pr) +{ + int ret; + + ret = acpi_processor_get_lpi_info(pr); + if (ret) + ret = acpi_processor_get_cstate_info(pr); + + return ret; +} + int acpi_processor_hotplug(struct acpi_processor *pr) { int ret = 0; @@ -978,18 +1340,15 @@ int acpi_processor_hotplug(struct acpi_processor *pr) if (disabled_by_idle_boot_param()) return 0; - if (nocst) - return -ENODEV; - if (!pr->flags.power_setup_done) return -ENODEV; dev = per_cpu(acpi_cpuidle_device, pr->id); cpuidle_pause_and_lock(); cpuidle_disable_device(dev); - acpi_processor_get_power_info(pr); - if (pr->flags.power) { - acpi_processor_setup_cpuidle_cx(pr, dev); + ret = acpi_processor_get_power_info(pr); + if (!ret && pr->flags.power) { + acpi_processor_setup_cpuidle_dev(pr, dev); ret = cpuidle_enable_device(dev); } cpuidle_resume_and_unlock(); @@ -997,7 +1356,7 @@ int acpi_processor_hotplug(struct acpi_processor *pr) return ret; } -int acpi_processor_cst_has_changed(struct acpi_processor *pr) +int acpi_processor_power_state_has_changed(struct acpi_processor *pr) { int cpu; struct acpi_processor *_pr; @@ -1006,9 +1365,6 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr) if (disabled_by_idle_boot_param()) return 0; - if (nocst) - return -ENODEV; - if (!pr->flags.power_setup_done) return -ENODEV; @@ -1045,7 +1401,7 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr) acpi_processor_get_power_info(_pr); if (_pr->flags.power) { dev = per_cpu(acpi_cpuidle_device, cpu); - acpi_processor_setup_cpuidle_cx(_pr, dev); + acpi_processor_setup_cpuidle_dev(_pr, dev); cpuidle_enable_device(dev); } } @@ -1092,7 +1448,7 @@ int acpi_processor_power_init(struct acpi_processor *pr) return -ENOMEM; per_cpu(acpi_cpuidle_device, pr->id) = dev; - acpi_processor_setup_cpuidle_cx(pr, dev); + acpi_processor_setup_cpuidle_dev(pr, dev); /* Register per-cpu cpuidle_device. Cpuidle driver * must already be registered before registering device |