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authorSudeep Holla <Sudeep.Holla@arm.com>2016-07-21 19:18:07 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-07-22 00:25:58 +0300
commita36a7fecfe6071732075ad5aa31196adce13181b (patch)
treee3d88c1b278e013b10bd1280dc0257d5b23cba3c /drivers/acpi/processor_idle.c
parent35ae713355868aa493edbfbabf615473473215cc (diff)
downloadlinux-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/processor_idle.c')
-rw-r--r--drivers/acpi/processor_idle.c466
1 files changed, 411 insertions, 55 deletions
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