diff mbox

[v3,5/5] ACPI / processor_idle: Add support for Low Power Idle(LPI) states

Message ID 1449065446-26115-6-git-send-email-sudeep.holla@arm.com
State New
Headers show

Commit Message

Sudeep Holla Dec. 2, 2015, 2:10 p.m. UTC
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.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

---
 drivers/acpi/Kconfig            |   3 +
 drivers/acpi/bus.c              |   8 +-
 drivers/acpi/processor_driver.c |   2 +-
 drivers/acpi/processor_idle.c   | 440 +++++++++++++++++++++++++++++++++++-----
 include/acpi/processor.h        |  30 ++-
 include/linux/acpi.h            |   4 +
 6 files changed, 435 insertions(+), 52 deletions(-)

-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/
diff mbox

Patch

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 12873f0b8141..89a2d9b81feb 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -51,6 +51,9 @@  config ARCH_MIGHT_HAVE_ACPI_PDC
 config ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE
 	bool
 
+config ARCH_SUPPORTS_ACPI_PROCESSOR_LPI
+	bool
+
 config ACPI_GENERIC_GSI
 	bool
 
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index a212cefae524..2e9e2e3fde6a 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -301,6 +301,7 @@  acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
 EXPORT_SYMBOL(acpi_run_osc);
 
 bool osc_sb_apei_support_acked;
+bool osc_pc_lpi_support_acked;
 static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
 static void acpi_bus_osc_support(void)
 {
@@ -321,6 +322,8 @@  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;
+	if (IS_ENABLED(CONFIG_ARCH_SUPPORTS_ACPI_PROCESSOR_LPI))
+		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PCLPI_SUPPORT;
 
 	if (!ghes_disable)
 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT;
@@ -328,9 +331,12 @@  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_acked =
+				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 29f787b2493f..bfc59de0ce6b 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 9ca840c88f48..73192c08bc8c 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -576,7 +576,7 @@  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 +810,12 @@  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 +838,13 @@  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 +856,7 @@  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;
@@ -943,24 +906,407 @@  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;
 }
-
 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 					   struct cpuidle_device *dev)
 {
 	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
+
+#ifdef CONFIG_ARCH_SUPPORTS_ACPI_PROCESSOR_LPI
+
+#define ACPI_LPI_STATE_FLAGS_ENABLED			BIT(0)
+
+struct acpi_processor_lpi_info {
+	int state_count;
+	struct acpi_processor_lpi *lpix;
+};
+
+static int acpi_processor_evaluate_lpi(acpi_handle handle,
+				       struct acpi_processor_lpi_info *info)
+{
+	acpi_status status = 0;
+	int ret;
+	int version, level, pkg_count, state_idx = 1, loop;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *lpi;
+	struct acpi_processor_lpi *lpix;
+
+	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 = buffer.pointer;
+
+	/* There must be at least 4 elements = 3 elements + 1 package */
+	if (!lpi || lpi->type != ACPI_TYPE_PACKAGE || lpi->package.count < 4) {
+		pr_info("not enough elements in _LPI\n");
+		ret = -EFAULT;
+		goto end;
+	}
+
+	version = lpi->package.elements[0].integer.value;
+	level = lpi->package.elements[1].integer.value;
+	pkg_count = lpi->package.elements[2].integer.value;
+
+	/* Validate number of power states. */
+	if (pkg_count < 1 || pkg_count != lpi->package.count - 3) {
+		pr_err("count given by _LPI is not valid\n");
+		ret = -EFAULT;
+		goto end;
+	}
+
+	lpix = kcalloc(pkg_count, sizeof(*lpix), GFP_KERNEL);
+	if (!lpix) {
+		ret = -ENOMEM;
+		goto end;
+	}
+
+	info->state_count = pkg_count;
+	info->lpix = lpix;
+	/* LPI States start at index 3 */
+	for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpix++) {
+		union acpi_object *element, *obj;
+
+		element = &lpi->package.elements[loop];
+		if (element->type != ACPI_TYPE_PACKAGE)
+			continue;
+
+		if (element->package.count < 7)
+			continue;
+
+		/* TODO this long list is looking insane now
+		 * need a cleaner and saner way to read the elements
+		 */
+		obj = &element->package.elements[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;
+			lpix->address = reg->address;
+			if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE)
+				lpix->entry_method = ACPI_CSTATE_FFH;
+			else
+				lpix->entry_method = ACPI_CSTATE_SYSTEMIO;
+		} else if (obj->type == ACPI_TYPE_INTEGER) {
+			lpix->entry_method = ACPI_CSTATE_INTEGER;
+			lpix->address = obj->integer.value;
+		} else {
+			continue;
+		}
+
+		/* elements[7,8] skipped for now i.e. Residency/Usage counter*/
+
+		obj = &element->package.elements[9];
+		if (obj->type == ACPI_TYPE_STRING)
+			strlcpy(lpix->desc, obj->string.pointer,
+				ACPI_CX_DESC_LEN);
+
+		lpix->index = state_idx;
+
+		obj = &element->package.elements[0];
+		if (obj->type != ACPI_TYPE_INTEGER)
+			continue;
+		lpix->min_residency = obj->integer.value;
+
+		obj = &element->package.elements[1];
+		if (obj->type != ACPI_TYPE_INTEGER)
+			continue;
+		lpix->wake_latency = obj->integer.value;
+
+		obj = &element->package.elements[2];
+		if (obj->type != ACPI_TYPE_INTEGER)
+			continue;
+		lpix->flags = obj->integer.value;
+
+		obj = &element->package.elements[3];
+		if (obj->type != ACPI_TYPE_INTEGER)
+			continue;
+		lpix->arch_flags = obj->integer.value;
+
+		obj = &element->package.elements[4];
+		if (obj->type != ACPI_TYPE_INTEGER)
+			continue;
+		lpix->res_cnt_freq = obj->integer.value;
+
+		obj = &element->package.elements[5];
+		if (obj->type != ACPI_TYPE_INTEGER)
+			continue;
+		lpix->enable_parent_state = obj->integer.value;
+	}
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
+			  state_idx));
+end:
+	kfree(buffer.pointer);
+	return status;
+}
+
+static int max_leaf_depth, fl_scnt;
+/**
+ * combine_lpi_states - combine local and parent LPI states to form a
+ *			composite LPI state
+ * @l_lpi: local LPI state
+ * @p_lpi: parent LPI state
+ * @c_lpi: composite LPI state
+ */
+static void combine_lpi_states(struct acpi_processor_lpi *l_lpi,
+			       struct acpi_processor_lpi *p_lpi,
+			       struct acpi_processor_lpi *c_lpi)
+{
+	c_lpi->min_residency = max(l_lpi->min_residency, p_lpi->min_residency);
+	c_lpi->wake_latency = l_lpi->wake_latency + p_lpi->wake_latency;
+	c_lpi->enable_parent_state = p_lpi->enable_parent_state;
+
+	if (p_lpi->entry_method == ACPI_CSTATE_INTEGER) {
+		c_lpi->entry_method = l_lpi->entry_method;
+		c_lpi->address = l_lpi->address + p_lpi->address;
+	} else {
+		c_lpi->entry_method = l_lpi->entry_method;
+		c_lpi->address = p_lpi->address;
+	}
+
+	c_lpi->index = p_lpi->index;
+	c_lpi->flags = p_lpi->flags;
+	c_lpi->arch_flags = p_lpi->arch_flags;
+
+	strlcpy(c_lpi->desc, l_lpi->desc, ACPI_CX_DESC_LEN);
+	strlcat(c_lpi->desc, "+", ACPI_CX_DESC_LEN);
+	strlcat(c_lpi->desc, p_lpi->desc, ACPI_CX_DESC_LEN);
+}
+
+static int flatten_lpi_states(struct acpi_processor *pr,
+			      struct acpi_processor_lpi_info *info,
+			      struct acpi_processor_lpi *lpi,
+			      uint32_t depth)
+{
+	int j, scount = info[depth].state_count;
+	struct acpi_processor_lpi *t = info[depth].lpix;
+
+	for (j = 0; j < scount; j++, t++) {
+		struct acpi_processor_lpi *flpi;
+		bool valid = false;
+
+		if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
+			continue;
+
+		flpi = &pr->power.lpi_states[fl_scnt];
+		if (depth == max_leaf_depth) { /* leaf/processor node */
+			memcpy(flpi, t, sizeof(*t));
+			fl_scnt++;
+			valid = true;
+		} else if (lpi && t->index <= lpi->enable_parent_state) {
+			combine_lpi_states(lpi, t, flpi);
+			fl_scnt++;
+			valid = true;
+		}
+
+		/*
+		 * flatten recursively from leaf until the highest level
+		 * (e.g. system) is reached
+		 */
+		if (valid && depth)
+			flatten_lpi_states(pr, info, flpi, depth - 1);
+	}
+	return 0;
+}
+
+static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
+{
+	int ret, i;
+	struct acpi_processor_lpi_info *info;
+	struct acpi_device *d = NULL;
+	acpi_handle handle = pr->handle, phandle;
+	acpi_status status;
+
+	if (!osc_pc_lpi_support_acked)
+		return -EOPNOTSUPP;
+
+	max_leaf_depth = 0;
+	if (!acpi_has_method(handle, "_LPI"))
+		return -EINVAL;
+	fl_scnt = 0;
+
+	while (ACPI_SUCCESS(status = acpi_get_parent(handle, &phandle))) {
+		if (!acpi_has_method(handle, "_LPI"))
+			continue;
+		acpi_bus_get_device(handle, &d);
+		if (!strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
+			break;
+		max_leaf_depth++;
+		handle = phandle;
+	}
+
+	info = kcalloc(max_leaf_depth + 1, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	phandle = pr->handle;
+	for (i = max_leaf_depth; i >= 0 && ACPI_SUCCESS(status); i--) {
+		handle = phandle;
+		ret = acpi_processor_evaluate_lpi(handle, info + i);
+		if (ret)
+			break;
+		status = acpi_get_parent(handle, &phandle);
+	}
+
+	/* flatten all the LPI states in the entire hierarchy */
+	flatten_lpi_states(pr, info, NULL, max_leaf_depth);
+
+	pr->power.count = fl_scnt;
+	for (i = 0; i <= max_leaf_depth; i++)
+		kfree(info[i].lpix);
+	kfree(info);
+
+	/* Tell driver that _LPI is supported. */
+	pr->flags.has_lpi = 1;
+	pr->flags.power = 1;
+
+	return 0;
+}
+
+/**
+ * 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_processor_lpi *lpi;
+
+	pr = __this_cpu_read(processors);
+
+	if (unlikely(!pr))
+		return -EINVAL;
+
+	lpi = &pr->power.lpi_states[index];
+	if (lpi->entry_method == ACPI_CSTATE_FFH)
+		/* Call into architectural FFH based C-state */
+		return acpi_processor_ffh_lpi_enter(lpi, index);
 	return -EINVAL;
 }
 
+static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
+{
+	int i;
+	struct acpi_processor_lpi *lpi;
+	struct cpuidle_state *state;
+	struct cpuidle_driver *drv = &acpi_idle_driver;
+
+	for (i = 0; i < fl_scnt && 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;
+}
+
+#else
+static int acpi_processor_ffh_lpi_probe(unsigned int cpu) { return -ENODEV; }
+static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
+{
+	return -ENODEV;
+}
+
+static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
+{
+	return -EINVAL;
+}
 #endif
 
+/**
+ * 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)
+		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 (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)
+		return -EINVAL;
+
+	if (pr->flags.power == 0)
+		return -EINVAL;
+
+	if (!dev)
+		return -EINVAL;
+
+	dev->cpu = pr->id;
+	if (pr->flags.has_lpi)
+		return acpi_processor_ffh_lpi_probe(pr->id);
+	else
+		return acpi_processor_setup_cpuidle_cx(pr, dev);
+}
+
+static int acpi_processor_get_power_info(struct acpi_processor *pr)
+{
+	int ret = 0;
+
+	ret = acpi_processor_get_cstate_info(pr);
+	if (ret)
+		ret = acpi_processor_get_lpi_info(pr);
+	return ret;
+}
+
 int acpi_processor_hotplug(struct acpi_processor *pr)
 {
 	int ret = 0;
@@ -980,7 +1326,7 @@  int acpi_processor_hotplug(struct acpi_processor *pr)
 	cpuidle_disable_device(dev);
 	acpi_processor_get_power_info(pr);
 	if (pr->flags.power) {
-		acpi_processor_setup_cpuidle_cx(pr, dev);
+		acpi_processor_setup_cpuidle_dev(pr, dev);
 		ret = cpuidle_enable_device(dev);
 	}
 	cpuidle_resume_and_unlock();
@@ -988,7 +1334,7 @@  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;
@@ -1036,7 +1382,7 @@  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);
 			}
 		}
@@ -1093,7 +1439,7 @@  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
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 50f2423d31fa..f3006831d427 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -39,6 +39,7 @@ 
 #define ACPI_CSTATE_SYSTEMIO	0
 #define ACPI_CSTATE_FFH		1
 #define ACPI_CSTATE_HALT	2
+#define ACPI_CSTATE_INTEGER	3
 
 #define ACPI_CX_DESC_LEN	32
 
@@ -67,9 +68,25 @@  struct acpi_processor_cx {
 	char desc[ACPI_CX_DESC_LEN];
 };
 
+struct acpi_processor_lpi {
+	u32 min_residency;
+	u32 wake_latency; /* worst case */
+	u32 flags;
+	u32 arch_flags;
+	u32 res_cnt_freq;
+	u32 enable_parent_state;
+	u64 address;
+	u8 index;
+	u8 entry_method;
+	char desc[ACPI_CX_DESC_LEN];
+};
+
 struct acpi_processor_power {
 	int count;
-	struct acpi_processor_cx states[ACPI_PROCESSOR_MAX_POWER];
+	union {
+		struct acpi_processor_cx states[ACPI_PROCESSOR_MAX_POWER];
+		struct acpi_processor_lpi lpi_states[ACPI_PROCESSOR_MAX_POWER];
+	};
 	int timer_broadcast_on_state;
 };
 
@@ -189,6 +206,7 @@  struct acpi_processor_flags {
 	u8 bm_control:1;
 	u8 bm_check:1;
 	u8 has_cst:1;
+	u8 has_lpi:1;
 	u8 power_setup_done:1;
 	u8 bm_rld_set:1;
 	u8 need_hotplug_init:1;
@@ -272,6 +290,11 @@  static inline void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx
 }
 #endif
 
+#ifdef CONFIG_ARCH_SUPPORTS_ACPI_PROCESSOR_LPI
+int acpi_processor_ffh_lpi_probe(unsigned int cpu);
+int acpi_processor_ffh_lpi_enter(struct acpi_processor_lpi *lpi, int idx);
+#endif
+
 /* in processor_perflib.c */
 
 #ifdef CONFIG_CPU_FREQ
@@ -372,7 +395,7 @@  extern struct cpuidle_driver acpi_idle_driver;
 #ifdef CONFIG_ACPI_PROCESSOR_IDLE
 int acpi_processor_power_init(struct acpi_processor *pr);
 int acpi_processor_power_exit(struct acpi_processor *pr);
-int acpi_processor_cst_has_changed(struct acpi_processor *pr);
+int acpi_processor_power_state_has_changed(struct acpi_processor *pr);
 int acpi_processor_hotplug(struct acpi_processor *pr);
 #else
 static inline int acpi_processor_power_init(struct acpi_processor *pr)
@@ -385,7 +408,8 @@  static inline int acpi_processor_power_exit(struct acpi_processor *pr)
 	return -ENODEV;
 }
 
-static inline int acpi_processor_cst_has_changed(struct acpi_processor *pr)
+static inline int
+acpi_processor_power_state_has_changed(struct acpi_processor *pr)
 {
 	return -ENODEV;
 }
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 054833939995..962a63b266cc 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -380,8 +380,12 @@  acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context);
 #define OSC_SB_HOTPLUG_OST_SUPPORT		0x00000008
 #define OSC_SB_APEI_SUPPORT			0x00000010
 #define OSC_SB_CPC_SUPPORT			0x00000020
+#define OSC_SB_CPCV2_SUPPORT			0x00000040
+#define OSC_SB_PCLPI_SUPPORT			0x00000080
+#define OSC_SB_OSLPI_SUPPORT			0x00000100
 
 extern bool osc_sb_apei_support_acked;
+extern bool osc_pc_lpi_support_acked;
 
 /* PCI Host Bridge _OSC: Capabilities DWORD 2: Support Field */
 #define OSC_PCI_EXT_CONFIG_SUPPORT		0x00000001