Merge branch 'pm-cpuidle'

* pm-cpuidle: (27 commits)
  intel_idle: Clean up irtl_2_usec()
  intel_idle: Move 3 functions closer to their callers
  intel_idle: Annotate initialization code and data structures
  intel_idle: Move and clean up intel_idle_cpuidle_devices_uninit()
  intel_idle: Rearrange intel_idle_cpuidle_driver_init()
  intel_idle: Clean up NULL pointer check in intel_idle_init()
  intel_idle: Fold intel_idle_probe() into intel_idle_init()
  intel_idle: Eliminate __setup_broadcast_timer()
  cpuidle: fix cpuidle_find_deepest_state() kerneldoc warnings
  cpuidle: sysfs: fix warnings when compiling with W=1
  cpuidle: coupled: fix warnings when compiling with W=1
  Documentation: admin-guide: PM: Add intel_idle document
  cpuidle: arm: Enable compile testing for some of drivers
  cpuidle: Drop unused cpuidle_driver_ref/unref() functions
  intel_idle: Use ACPI _CST on server systems
  intel_idle: Add module parameter to prevent ACPI _CST from being used
  intel_idle: Allow ACPI _CST to be used for selected known processors
  cpuidle: Allow idle states to be disabled by default
  intel_idle: Use ACPI _CST for processor models without C-state tables
  intel_idle: Refactor intel_idle_cpuidle_driver_init()
  ...

11 files changed, 564 insertions, 377 deletions

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 002838d23b86..cc57bab146b5 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -241,6 +241,7 @@ config ACPI_CPU_FREQ_PSS
 
 config ACPI_PROCESSOR_CSTATE
 	def_bool y
+	depends on ACPI_PROCESSOR
 	depends on IA64 || X86
 
 config ACPI_PROCESSOR_IDLE
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 2c4dda0787e8..5379bc3f275d 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -705,3 +705,185 @@ void __init acpi_processor_init(void)
 	acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
 	acpi_scan_add_handler(&processor_container_handler);
 }
+
+#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
+/**
+ * acpi_processor_claim_cst_control - Request _CST control from the platform.
+ */
+bool acpi_processor_claim_cst_control(void)
+{
+	static bool cst_control_claimed;
+	acpi_status status;
+
+	if (!acpi_gbl_FADT.cst_control || cst_control_claimed)
+		return true;
+
+	status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
+				    acpi_gbl_FADT.cst_control, 8);
+	if (ACPI_FAILURE(status)) {
+		pr_warn("ACPI: Failed to claim processor _CST control\n");
+		return false;
+	}
+
+	cst_control_claimed = true;
+	return true;
+}
+EXPORT_SYMBOL_GPL(acpi_processor_claim_cst_control);
+
+/**
+ * acpi_processor_evaluate_cst - Evaluate the processor _CST control method.
+ * @handle: ACPI handle of the processor object containing the _CST.
+ * @cpu: The numeric ID of the target CPU.
+ * @info: Object write the C-states information into.
+ *
+ * Extract the C-state information for the given CPU from the output of the _CST
+ * control method under the corresponding ACPI processor object (or processor
+ * device object) and populate @info with it.
+ *
+ * If any ACPI_ADR_SPACE_FIXED_HARDWARE C-states are found, invoke
+ * acpi_processor_ffh_cstate_probe() to verify them and update the
+ * cpu_cstate_entry data for @cpu.
+ */
+int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
+				struct acpi_processor_power *info)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *cst;
+	acpi_status status;
+	u64 count;
+	int last_index = 0;
+	int i, ret = 0;
+
+	status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
+	if (ACPI_FAILURE(status)) {
+		acpi_handle_debug(handle, "No _CST\n");
+		return -ENODEV;
+	}
+
+	cst = buffer.pointer;
+
+	/* There must be at least 2 elements. */
+	if (!cst || cst->type != ACPI_TYPE_PACKAGE || cst->package.count < 2) {
+		acpi_handle_warn(handle, "Invalid _CST output\n");
+		ret = -EFAULT;
+		goto end;
+	}
+
+	count = cst->package.elements[0].integer.value;
+
+	/* Validate the number of C-states. */
+	if (count < 1 || count != cst->package.count - 1) {
+		acpi_handle_warn(handle, "Inconsistent _CST data\n");
+		ret = -EFAULT;
+		goto end;
+	}
+
+	for (i = 1; i <= count; i++) {
+		union acpi_object *element;
+		union acpi_object *obj;
+		struct acpi_power_register *reg;
+		struct acpi_processor_cx cx;
+
+		/*
+		 * If there is not enough space for all C-states, skip the
+		 * excess ones and log a warning.
+		 */
+		if (last_index >= ACPI_PROCESSOR_MAX_POWER - 1) {
+			acpi_handle_warn(handle,
+					 "No room for more idle states (limit: %d)\n",
+					 ACPI_PROCESSOR_MAX_POWER - 1);
+			break;
+		}
+
+		memset(&cx, 0, sizeof(cx));
+
+		element = &cst->package.elements[i];
+		if (element->type != ACPI_TYPE_PACKAGE)
+			continue;
+
+		if (element->package.count != 4)
+			continue;
+
+		obj = &element->package.elements[0];
+
+		if (obj->type != ACPI_TYPE_BUFFER)
+			continue;
+
+		reg = (struct acpi_power_register *)obj->buffer.pointer;
+
+		obj = &element->package.elements[1];
+		if (obj->type != ACPI_TYPE_INTEGER)
+			continue;
+
+		cx.type = obj->integer.value;
+		/*
+		 * There are known cases in which the _CST output does not
+		 * contain C1, so if the type of the first state found is not
+		 * C1, leave an empty slot for C1 to be filled in later.
+		 */
+		if (i == 1 && cx.type != ACPI_STATE_C1)
+			last_index = 1;
+
+		cx.address = reg->address;
+		cx.index = last_index + 1;
+
+		if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
+			if (!acpi_processor_ffh_cstate_probe(cpu, &cx, reg)) {
+				/*
+				 * In the majority of cases _CST describes C1 as
+				 * a FIXED_HARDWARE C-state, but if the command
+				 * line forbids using MWAIT, use CSTATE_HALT for
+				 * C1 regardless.
+				 */
+				if (cx.type == ACPI_STATE_C1 &&
+				    boot_option_idle_override == IDLE_NOMWAIT) {
+					cx.entry_method = ACPI_CSTATE_HALT;
+					snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
+				} else {
+					cx.entry_method = ACPI_CSTATE_FFH;
+				}
+			} else if (cx.type == ACPI_STATE_C1) {
+				/*
+				 * In the special case of C1, FIXED_HARDWARE can
+				 * be handled by executing the HLT instruction.
+				 */
+				cx.entry_method = ACPI_CSTATE_HALT;
+				snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
+			} else {
+				continue;
+			}
+		} else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
+			cx.entry_method = ACPI_CSTATE_SYSTEMIO;
+			snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
+				 cx.address);
+		} else {
+			continue;
+		}
+
+		if (cx.type == ACPI_STATE_C1)
+			cx.valid = 1;
+
+		obj = &element->package.elements[2];
+		if (obj->type != ACPI_TYPE_INTEGER)
+			continue;
+
+		cx.latency = obj->integer.value;
+
+		obj = &element->package.elements[3];
+		if (obj->type != ACPI_TYPE_INTEGER)
+			continue;
+
+		memcpy(&info->states[++last_index], &cx, sizeof(cx));
+	}
+
+	acpi_handle_info(handle, "Found %d idle states\n", last_index);
+
+	info->count = last_index;
+
+      end:
+	kfree(buffer.pointer);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_processor_evaluate_cst);
+#endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 2ae95df2e74f..dcc289e30166 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -299,164 +299,24 @@ static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 
 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 {
-	acpi_status status;
-	u64 count;
-	int current_count;
-	int i, ret = 0;
-	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *cst;
+	int ret;
 
 	if (nocst)
 		return -ENODEV;
 
-	current_count = 0;
-
-	status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
-	if (ACPI_FAILURE(status)) {
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
-		return -ENODEV;
-	}
-
-	cst = buffer.pointer;
-
-	/* There must be at least 2 elements */
-	if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
-		pr_err("not enough elements in _CST\n");
-		ret = -EFAULT;
-		goto end;
-	}
-
-	count = cst->package.elements[0].integer.value;
+	ret = acpi_processor_evaluate_cst(pr->handle, pr->id, &pr->power);
+	if (ret)
+		return ret;
 
-	/* Validate number of power states. */
-	if (count < 1 || count != cst->package.count - 1) {
-		pr_err("count given by _CST is not valid\n");
-		ret = -EFAULT;
-		goto end;
-	}
+	/*
+	 * It is expected that there will be at least 2 states, C1 and
+	 * something else (C2 or C3), so fail if that is not the case.
+	 */
+	if (pr->power.count < 2)
+		return -EFAULT;
 
-	/* Tell driver that at least _CST is supported. */
 	pr->flags.has_cst = 1;
-
-	for (i = 1; i <= count; i++) {
-		union acpi_object *element;
-		union acpi_object *obj;
-		struct acpi_power_register *reg;
-		struct acpi_processor_cx cx;
-
-		memset(&cx, 0, sizeof(cx));
-
-		element = &(cst->package.elements[i]);
-		if (element->type != ACPI_TYPE_PACKAGE)
-			continue;
-
-		if (element->package.count != 4)
-			continue;
-
-		obj = &(element->package.elements[0]);
-
-		if (obj->type != ACPI_TYPE_BUFFER)
-			continue;
-
-		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;
-
-		/* There should be an easy way to extract an integer... */
-		obj = &(element->package.elements[1]);
-		if (obj->type != ACPI_TYPE_INTEGER)
-			continue;
-
-		cx.type = obj->integer.value;
-		/*
-		 * Some buggy BIOSes won't list C1 in _CST -
-		 * Let acpi_processor_get_power_info_default() handle them later
-		 */
-		if (i == 1 && cx.type != ACPI_STATE_C1)
-			current_count++;
-
-		cx.address = reg->address;
-		cx.index = current_count + 1;
-
-		cx.entry_method = ACPI_CSTATE_SYSTEMIO;
-		if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
-			if (acpi_processor_ffh_cstate_probe
-					(pr->id, &cx, reg) == 0) {
-				cx.entry_method = ACPI_CSTATE_FFH;
-			} else if (cx.type == ACPI_STATE_C1) {
-				/*
-				 * C1 is a special case where FIXED_HARDWARE
-				 * can be handled in non-MWAIT way as well.
-				 * In that case, save this _CST entry info.
-				 * Otherwise, ignore this info and continue.
-				 */
-				cx.entry_method = ACPI_CSTATE_HALT;
-				snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
-			} else {
-				continue;
-			}
-			if (cx.type == ACPI_STATE_C1 &&
-			    (boot_option_idle_override == IDLE_NOMWAIT)) {
-				/*
-				 * In most cases the C1 space_id obtained from
-				 * _CST object is FIXED_HARDWARE access mode.
-				 * But when the option of idle=halt is added,
-				 * the entry_method type should be changed from
-				 * CSTATE_FFH to CSTATE_HALT.
-				 * When the option of idle=nomwait is added,
-				 * the C1 entry_method type should be
-				 * CSTATE_HALT.
-				 */
-				cx.entry_method = ACPI_CSTATE_HALT;
-				snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
-			}
-		} else {
-			snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
-				 cx.address);
-		}
-
-		if (cx.type == ACPI_STATE_C1) {
-			cx.valid = 1;
-		}
-
-		obj = &(element->package.elements[2]);
-		if (obj->type != ACPI_TYPE_INTEGER)
-			continue;
-
-		cx.latency = obj->integer.value;
-
-		obj = &(element->package.elements[3]);
-		if (obj->type != ACPI_TYPE_INTEGER)
-			continue;
-
-		current_count++;
-		memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
-
-		/*
-		 * We support total ACPI_PROCESSOR_MAX_POWER - 1
-		 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
-		 */
-		if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
-			pr_warn("Limiting number of power states to max (%d)\n",
-				ACPI_PROCESSOR_MAX_POWER);
-			pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
-			break;
-		}
-	}
-
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
-			  current_count));
-
-	/* Validate number of power states discovered */
-	if (current_count < 2)
-		ret = -EFAULT;
-
-      end:
-	kfree(buffer.pointer);
-
-	return ret;
+	return 0;
 }
 
 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
@@ -909,7 +769,6 @@ static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 
 static inline void acpi_processor_cstate_first_run_checks(void)
 {
-	acpi_status status;
 	static int first_run;
 
 	if (first_run)
@@ -921,13 +780,10 @@ static inline void acpi_processor_cstate_first_run_checks(void)
 			  max_cstate);
 	first_run++;
 
-	if (acpi_gbl_FADT.cst_control && !nocst) {
-		status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
-					    acpi_gbl_FADT.cst_control, 8);
-		if (ACPI_FAILURE(status))
-			ACPI_EXCEPTION((AE_INFO, status,
-					"Notifying BIOS of _CST ability failed"));
-	}
+	if (nocst)
+		return;
+
+	acpi_processor_claim_cst_control();
 }
 #else
 
diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
index a224d33dda7f..62272ecfa771 100644
--- a/drivers/cpuidle/Kconfig.arm
+++ b/drivers/cpuidle/Kconfig.arm
@@ -25,7 +25,7 @@ config ARM_PSCI_CPUIDLE
 
 config ARM_BIG_LITTLE_CPUIDLE
 	bool "Support for ARM big.LITTLE processors"
-	depends on ARCH_VEXPRESS_TC2_PM || ARCH_EXYNOS
+	depends on ARCH_VEXPRESS_TC2_PM || ARCH_EXYNOS || COMPILE_TEST
 	depends on MCPM && !ARM64
 	select ARM_CPU_SUSPEND
 	select CPU_IDLE_MULTIPLE_DRIVERS
@@ -51,13 +51,13 @@ config ARM_HIGHBANK_CPUIDLE
 
 config ARM_KIRKWOOD_CPUIDLE
 	bool "CPU Idle Driver for Marvell Kirkwood SoCs"
-	depends on MACH_KIRKWOOD && !ARM64
+	depends on (MACH_KIRKWOOD || COMPILE_TEST) && !ARM64
 	help
 	  This adds the CPU Idle driver for Marvell Kirkwood SoCs.
 
 config ARM_ZYNQ_CPUIDLE
 	bool "CPU Idle Driver for Xilinx Zynq processors"
-	depends on ARCH_ZYNQ && !ARM64
+	depends on (ARCH_ZYNQ || COMPILE_TEST) && !ARM64
 	help
 	  Select this to enable cpuidle on Xilinx Zynq processors.
 
@@ -70,19 +70,19 @@ config ARM_U8500_CPUIDLE
 config ARM_AT91_CPUIDLE
 	bool "Cpu Idle Driver for the AT91 processors"
 	default y
-	depends on ARCH_AT91 && !ARM64
+	depends on (ARCH_AT91 || COMPILE_TEST) && !ARM64
 	help
 	  Select this to enable cpuidle for AT91 processors.
 
 config ARM_EXYNOS_CPUIDLE
 	bool "Cpu Idle Driver for the Exynos processors"
-	depends on ARCH_EXYNOS && !ARM64
+	depends on (ARCH_EXYNOS || COMPILE_TEST) && !ARM64
 	select ARCH_NEEDS_CPU_IDLE_COUPLED if SMP
 	help
 	  Select this to enable cpuidle for Exynos processors.
 
 config ARM_MVEBU_V7_CPUIDLE
 	bool "CPU Idle Driver for mvebu v7 family processors"
-	depends on ARCH_MVEBU && !ARM64
+	depends on (ARCH_MVEBU || COMPILE_TEST) && !ARM64
 	help
 	  Select this to enable cpuidle on Armada 370, 38x and XP processors.
diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c
index b607278df25b..04003b90dc49 100644
--- a/drivers/cpuidle/coupled.c
+++ b/drivers/cpuidle/coupled.c
@@ -89,6 +89,7 @@
  * @coupled_cpus: mask of cpus that are part of the coupled set
  * @requested_state: array of requested states for cpus in the coupled set
  * @ready_waiting_counts: combined count of cpus  in ready or waiting loops
+ * @abort_barrier: synchronisation point for abort cases
  * @online_count: count of cpus that are online
  * @refcnt: reference count of cpuidle devices that are using this struct
  * @prevent: flag to prevent coupled idle while a cpu is hotplugging
@@ -338,7 +339,7 @@ static void cpuidle_coupled_poke(int cpu)
 
 /**
  * cpuidle_coupled_poke_others - wake up all other cpus that may be waiting
- * @dev: struct cpuidle_device for this cpu
+ * @this_cpu: target cpu
  * @coupled: the struct coupled that contains the current cpu
  *
  * Calls cpuidle_coupled_poke on all other online cpus.
@@ -355,7 +356,7 @@ static void cpuidle_coupled_poke_others(int this_cpu,
 
 /**
  * cpuidle_coupled_set_waiting - mark this cpu as in the wait loop
- * @dev: struct cpuidle_device for this cpu
+ * @cpu: target cpu
  * @coupled: the struct coupled that contains the current cpu
  * @next_state: the index in drv->states of the requested state for this cpu
  *
@@ -376,7 +377,7 @@ static int cpuidle_coupled_set_waiting(int cpu,
 
 /**
  * cpuidle_coupled_set_not_waiting - mark this cpu as leaving the wait loop
- * @dev: struct cpuidle_device for this cpu
+ * @cpu: target cpu
  * @coupled: the struct coupled that contains the current cpu
  *
  * Removes the requested idle state for the specified cpuidle device.
@@ -412,7 +413,7 @@ static void cpuidle_coupled_set_done(int cpu, struct cpuidle_coupled *coupled)
 
 /**
  * cpuidle_coupled_clear_pokes - spin until the poke interrupt is processed
- * @cpu - this cpu
+ * @cpu: this cpu
  *
  * Turns on interrupts and spins until any outstanding poke interrupts have
  * been processed and the poke bit has been cleared.
diff --git a/drivers/cpuidle/cpuidle-clps711x.c b/drivers/cpuidle/cpuidle-clps711x.c
index 6e36740f5719..fc22c59b6c73 100644
--- a/drivers/cpuidle/cpuidle-clps711x.c
+++ b/drivers/cpuidle/cpuidle-clps711x.c
@@ -37,10 +37,7 @@ static struct cpuidle_driver clps711x_idle_driver = {
 
 static int __init clps711x_cpuidle_probe(struct platform_device *pdev)
 {
-	struct resource *res;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	clps711x_halt = devm_ioremap_resource(&pdev->dev, res);
+	clps711x_halt = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(clps711x_halt))
 		return PTR_ERR(clps711x_halt);
 
diff --git a/drivers/cpuidle/cpuidle-kirkwood.c b/drivers/cpuidle/cpuidle-kirkwood.c
index d23d8f468c12..511c4f46027a 100644
--- a/drivers/cpuidle/cpuidle-kirkwood.c
+++ b/drivers/cpuidle/cpuidle-kirkwood.c
@@ -55,10 +55,7 @@ static struct cpuidle_driver kirkwood_idle_driver = {
 /* Initialize CPU idle by registering the idle states */
 static int kirkwood_cpuidle_probe(struct platform_device *pdev)
 {
-	struct resource *res;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	ddr_operation_base = devm_ioremap_resource(&pdev->dev, res);
+	ddr_operation_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(ddr_operation_base))
 		return PTR_ERR(ddr_operation_base);
 
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index 33d19c8eb027..de81298051b3 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -121,6 +121,9 @@ void cpuidle_use_deepest_state(u64 latency_limit_ns)
  * cpuidle_find_deepest_state - Find the deepest available idle state.
  * @drv: cpuidle driver for the given CPU.
  * @dev: cpuidle device for the given CPU.
+ * @latency_limit_ns: Idle state exit latency limit
+ *
+ * Return: the index of the deepest available idle state.
  */
 int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
 			       struct cpuidle_device *dev,
@@ -572,10 +575,14 @@ static int __cpuidle_register_device(struct cpuidle_device *dev)
 	if (!try_module_get(drv->owner))
 		return -EINVAL;
 
-	for (i = 0; i < drv->state_count; i++)
+	for (i = 0; i < drv->state_count; i++) {
 		if (drv->states[i].flags & CPUIDLE_FLAG_UNUSABLE)
 			dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_DRIVER;
 
+		if (drv->states[i].flags & CPUIDLE_FLAG_OFF)
+			dev->states_usage[i].disable |= CPUIDLE_STATE_DISABLED_BY_USER;
+	}
+
 	per_cpu(cpuidle_devices, dev->cpu) = dev;
 	list_add(&dev->device_list, &cpuidle_detected_devices);
 
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index ce6a5f80fb83..4070e573bf43 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -155,8 +155,6 @@ static void __cpuidle_driver_init(struct cpuidle_driver *drv)
 {
 	int i;
 
-	drv->refcnt = 0;
-
 	/*
 	 * Use all possible CPUs as the default, because if the kernel boots
 	 * with some CPUs offline and then we online one of them, the CPU
@@ -240,9 +238,6 @@ static int __cpuidle_register_driver(struct cpuidle_driver *drv)
  */
 static void __cpuidle_unregister_driver(struct cpuidle_driver *drv)
 {
-	if (WARN_ON(drv->refcnt > 0))
-		return;
-
 	if (drv->bctimer) {
 		drv->bctimer = 0;
 		on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,
@@ -350,47 +345,6 @@ struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev)
 EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver);
 
 /**
- * cpuidle_driver_ref - get a reference to the driver.
- *
- * Increment the reference counter of the cpuidle driver associated with
- * the current CPU.
- *
- * Returns a pointer to the driver, or NULL if the current CPU has no driver.
- */
-struct cpuidle_driver *cpuidle_driver_ref(void)
-{
-	struct cpuidle_driver *drv;
-
-	spin_lock(&cpuidle_driver_lock);
-
-	drv = cpuidle_get_driver();
-	if (drv)
-		drv->refcnt++;
-
-	spin_unlock(&cpuidle_driver_lock);
-	return drv;
-}
-
-/**
- * cpuidle_driver_unref - puts down the refcount for the driver
- *
- * Decrement the reference counter of the cpuidle driver associated with
- * the current CPU.
- */
-void cpuidle_driver_unref(void)
-{
-	struct cpuidle_driver *drv;
-
-	spin_lock(&cpuidle_driver_lock);
-
-	drv = cpuidle_get_driver();
-	if (drv && !WARN_ON(drv->refcnt <= 0))
-		drv->refcnt--;
-
-	spin_unlock(&cpuidle_driver_lock);
-}
-
-/**
  * cpuidle_driver_state_disabled - Disable or enable an idle state
  * @drv: cpuidle driver owning the state
  * @idx: State index
diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
index 38ef770be90d..cdeedbf02646 100644
--- a/drivers/cpuidle/sysfs.c
+++ b/drivers/cpuidle/sysfs.c
@@ -142,6 +142,7 @@ static struct attribute_group cpuidle_attr_group = {
 
 /**
  * cpuidle_add_interface - add CPU global sysfs attributes
+ * @dev: the target device
  */
 int cpuidle_add_interface(struct device *dev)
 {
@@ -153,6 +154,7 @@ int cpuidle_add_interface(struct device *dev)
 
 /**
  * cpuidle_remove_interface - remove CPU global sysfs attributes
+ * @dev: the target device
  */
 void cpuidle_remove_interface(struct device *dev)
 {
@@ -327,6 +329,14 @@ static ssize_t store_state_disable(struct cpuidle_state *state,
 	return size;
 }
 
+static ssize_t show_state_default_status(struct cpuidle_state *state,
+					  struct cpuidle_state_usage *state_usage,
+					  char *buf)
+{
+	return sprintf(buf, "%s\n",
+		       state->flags & CPUIDLE_FLAG_OFF ? "disabled" : "enabled");
+}
+
 define_one_state_ro(name, show_state_name);
 define_one_state_ro(desc, show_state_desc);
 define_one_state_ro(latency, show_state_exit_latency);
@@ -337,6 +347,7 @@ define_one_state_ro(time, show_state_time);
 define_one_state_rw(disable, show_state_disable, store_state_disable);
 define_one_state_ro(above, show_state_above);
 define_one_state_ro(below, show_state_below);
+define_one_state_ro(default_status, show_state_default_status);
 
 static struct attribute *cpuidle_state_default_attrs[] = {
 	&attr_name.attr,
@@ -349,6 +360,7 @@ static struct attribute *cpuidle_state_default_attrs[] = {
 	&attr_disable.attr,
 	&attr_above.attr,
 	&attr_below.attr,
+	&attr_default_status.attr,
 	NULL
 };
 
@@ -615,7 +627,7 @@ static struct kobj_type ktype_driver_cpuidle = {
 
 /**
  * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
- * @device: the target device
+ * @dev: the target device
  */
 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 {
@@ -646,7 +658,7 @@ static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 
 /**
  * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
- * @device: the target device
+ * @dev: the target device
  */
 static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
 {
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 75fd2a7b0842..9f38ff02a7b8 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -41,6 +41,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/acpi.h>
 #include <linux/kernel.h>
 #include <linux/cpuidle.h>
 #include <linux/tick.h>
@@ -79,6 +80,7 @@ struct idle_cpu {
 	unsigned long auto_demotion_disable_flags;
 	bool byt_auto_demotion_disable_flag;
 	bool disable_promotion_to_c1e;
+	bool use_acpi;
 };
 
 static const struct idle_cpu *icpu;
@@ -90,6 +92,11 @@ static void intel_idle_s2idle(struct cpuidle_device *dev,
 static struct cpuidle_state *cpuidle_state_table;
 
 /*
+ * Enable this state by default even if the ACPI _CST does not list it.
+ */
+#define CPUIDLE_FLAG_ALWAYS_ENABLE	BIT(15)
+
+/*
  * Set this flag for states where the HW flushes the TLB for us
  * and so we don't need cross-calls to keep it consistent.
  * If this flag is set, SW flushes the TLB, so even if the
@@ -124,7 +131,7 @@ static struct cpuidle_state nehalem_cstates[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 20,
 		.enter = &intel_idle,
@@ -161,7 +168,7 @@ static struct cpuidle_state snb_cstates[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 20,
 		.enter = &intel_idle,
@@ -296,7 +303,7 @@ static struct cpuidle_state ivb_cstates[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 20,
 		.enter = &intel_idle,
@@ -341,7 +348,7 @@ static struct cpuidle_state ivt_cstates[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 80,
 		.enter = &intel_idle,
@@ -378,7 +385,7 @@ static struct cpuidle_state ivt_cstates_4s[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 250,
 		.enter = &intel_idle,
@@ -415,7 +422,7 @@ static struct cpuidle_state ivt_cstates_8s[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 500,
 		.enter = &intel_idle,
@@ -452,7 +459,7 @@ static struct cpuidle_state hsw_cstates[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 20,
 		.enter = &intel_idle,
@@ -520,7 +527,7 @@ static struct cpuidle_state bdw_cstates[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 20,
 		.enter = &intel_idle,
@@ -589,7 +596,7 @@ static struct cpuidle_state skl_cstates[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 20,
 		.enter = &intel_idle,
@@ -658,7 +665,7 @@ static struct cpuidle_state skx_cstates[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 20,
 		.enter = &intel_idle,
@@ -808,7 +815,7 @@ static struct cpuidle_state bxt_cstates[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 20,
 		.enter = &intel_idle,
@@ -869,7 +876,7 @@ static struct cpuidle_state dnv_cstates[] = {
 	{
 		.name = "C1E",
 		.desc = "MWAIT 0x01",
-		.flags = MWAIT2flg(0x01),
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
 		.exit_latency = 10,
 		.target_residency = 20,
 		.enter = &intel_idle,
@@ -944,37 +951,19 @@ static void intel_idle_s2idle(struct cpuidle_device *dev,
 	mwait_idle_with_hints(eax, ecx);
 }
 
-static void __setup_broadcast_timer(bool on)
-{
-	if (on)
-		tick_broadcast_enable();
-	else
-		tick_broadcast_disable();
-}
-
-static void auto_demotion_disable(void)
-{
-	unsigned long long msr_bits;
-
-	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
-	msr_bits &= ~(icpu->auto_demotion_disable_flags);
-	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
-}
-static void c1e_promotion_disable(void)
-{
-	unsigned long long msr_bits;
-
-	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
-	msr_bits &= ~0x2;
-	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
-}
-
 static const struct idle_cpu idle_cpu_nehalem = {
 	.state_table = nehalem_cstates,
 	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
 	.disable_promotion_to_c1e = true,
 };
 
+static const struct idle_cpu idle_cpu_nhx = {
+	.state_table = nehalem_cstates,
+	.auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
+	.disable_promotion_to_c1e = true,
+	.use_acpi = true,
+};
+
 static const struct idle_cpu idle_cpu_atom = {
 	.state_table = atom_cstates,
 };
@@ -993,6 +982,12 @@ static const struct idle_cpu idle_cpu_snb = {
 	.disable_promotion_to_c1e = true,
 };
 
+static const struct idle_cpu idle_cpu_snx = {
+	.state_table = snb_cstates,
+	.disable_promotion_to_c1e = true,
+	.use_acpi = true,
+};
+
 static const struct idle_cpu idle_cpu_byt = {
 	.state_table = byt_cstates,
 	.disable_promotion_to_c1e = true,
@@ -1013,6 +1008,7 @@ static const struct idle_cpu idle_cpu_ivb = {
 static const struct idle_cpu idle_cpu_ivt = {
 	.state_table = ivt_cstates,
 	.disable_promotion_to_c1e = true,
+	.use_acpi = true,
 };
 
 static const struct idle_cpu idle_cpu_hsw = {
@@ -1020,11 +1016,23 @@ static const struct idle_cpu idle_cpu_hsw = {
 	.disable_promotion_to_c1e = true,
 };
 
+static const struct idle_cpu idle_cpu_hsx = {
+	.state_table = hsw_cstates,
+	.disable_promotion_to_c1e = true,
+	.use_acpi = true,
+};
+
 static const struct idle_cpu idle_cpu_bdw = {
 	.state_table = bdw_cstates,
 	.disable_promotion_to_c1e = true,
 };
 
+static const struct idle_cpu idle_cpu_bdx = {
+	.state_table = bdw_cstates,
+	.disable_promotion_to_c1e = true,
+	.use_acpi = true,
+};
+
 static const struct idle_cpu idle_cpu_skl = {
 	.state_table = skl_cstates,
 	.disable_promotion_to_c1e = true,
@@ -1033,15 +1041,18 @@ static const struct idle_cpu idle_cpu_skl = {
 static const struct idle_cpu idle_cpu_skx = {
 	.state_table = skx_cstates,
 	.disable_promotion_to_c1e = true,
+	.use_acpi = true,
 };
 
 static const struct idle_cpu idle_cpu_avn = {
 	.state_table = avn_cstates,
 	.disable_promotion_to_c1e = true,
+	.use_acpi = true,
 };
 
 static const struct idle_cpu idle_cpu_knl = {
 	.state_table = knl_cstates,
+	.use_acpi = true,
 };
 
 static const struct idle_cpu idle_cpu_bxt = {
@@ -1052,20 +1063,21 @@ static const struct idle_cpu idle_cpu_bxt = {
 static const struct idle_cpu idle_cpu_dnv = {
 	.state_table = dnv_cstates,
 	.disable_promotion_to_c1e = true,
+	.use_acpi = true,
 };
 
 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
-	INTEL_CPU_FAM6(NEHALEM_EP,		idle_cpu_nehalem),
+	INTEL_CPU_FAM6(NEHALEM_EP,		idle_cpu_nhx),
 	INTEL_CPU_FAM6(NEHALEM,			idle_cpu_nehalem),
 	INTEL_CPU_FAM6(NEHALEM_G,		idle_cpu_nehalem),
 	INTEL_CPU_FAM6(WESTMERE,		idle_cpu_nehalem),
-	INTEL_CPU_FAM6(WESTMERE_EP,		idle_cpu_nehalem),
-	INTEL_CPU_FAM6(NEHALEM_EX,		idle_cpu_nehalem),
+	INTEL_CPU_FAM6(WESTMERE_EP,		idle_cpu_nhx),
+	INTEL_CPU_FAM6(NEHALEM_EX,		idle_cpu_nhx),
 	INTEL_CPU_FAM6(ATOM_BONNELL,		idle_cpu_atom),
 	INTEL_CPU_FAM6(ATOM_BONNELL_MID,	idle_cpu_lincroft),
-	INTEL_CPU_FAM6(WESTMERE_EX,		idle_cpu_nehalem),
+	INTEL_CPU_FAM6(WESTMERE_EX,		idle_cpu_nhx),
 	INTEL_CPU_FAM6(SANDYBRIDGE,		idle_cpu_snb),
-	INTEL_CPU_FAM6(SANDYBRIDGE_X,		idle_cpu_snb),
+	INTEL_CPU_FAM6(SANDYBRIDGE_X,		idle_cpu_snx),
 	INTEL_CPU_FAM6(ATOM_SALTWELL,		idle_cpu_atom),
 	INTEL_CPU_FAM6(ATOM_SILVERMONT,		idle_cpu_byt),
 	INTEL_CPU_FAM6(ATOM_SILVERMONT_MID,	idle_cpu_tangier),
@@ -1073,14 +1085,14 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = {
 	INTEL_CPU_FAM6(IVYBRIDGE,		idle_cpu_ivb),
 	INTEL_CPU_FAM6(IVYBRIDGE_X,		idle_cpu_ivt),
 	INTEL_CPU_FAM6(HASWELL,			idle_cpu_hsw),
-	INTEL_CPU_FAM6(HASWELL_X,		idle_cpu_hsw),
+	INTEL_CPU_FAM6(HASWELL_X,		idle_cpu_hsx),
 	INTEL_CPU_FAM6(HASWELL_L,		idle_cpu_hsw),
 	INTEL_CPU_FAM6(HASWELL_G,		idle_cpu_hsw),
 	INTEL_CPU_FAM6(ATOM_SILVERMONT_D,	idle_cpu_avn),
 	INTEL_CPU_FAM6(BROADWELL,		idle_cpu_bdw),
 	INTEL_CPU_FAM6(BROADWELL_G,		idle_cpu_bdw),
-	INTEL_CPU_FAM6(BROADWELL_X,		idle_cpu_bdw),
-	INTEL_CPU_FAM6(BROADWELL_D,		idle_cpu_bdw),
+	INTEL_CPU_FAM6(BROADWELL_X,		idle_cpu_bdx),
+	INTEL_CPU_FAM6(BROADWELL_D,		idle_cpu_bdx),
 	INTEL_CPU_FAM6(SKYLAKE_L,		idle_cpu_skl),
 	INTEL_CPU_FAM6(SKYLAKE,			idle_cpu_skl),
 	INTEL_CPU_FAM6(KABYLAKE_L,		idle_cpu_skl),
@@ -1095,76 +1107,169 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = {
 	{}
 };
 
-/*
- * intel_idle_probe()
+#define INTEL_CPU_FAM6_MWAIT \
+	{ X86_VENDOR_INTEL, 6, X86_MODEL_ANY, X86_FEATURE_MWAIT, 0 }
+
+static const struct x86_cpu_id intel_mwait_ids[] __initconst = {
+	INTEL_CPU_FAM6_MWAIT,
+	{}
+};
+
+static bool __init intel_idle_max_cstate_reached(int cstate)
+{
+	if (cstate + 1 > max_cstate) {
+		pr_info("max_cstate %d reached\n", max_cstate);
+		return true;
+	}
+	return false;
+}
+
+#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
+#include <acpi/processor.h>
+
+static bool no_acpi __read_mostly;
+module_param(no_acpi, bool, 0444);
+MODULE_PARM_DESC(no_acpi, "Do not use ACPI _CST for building the idle states list");
+
+static struct acpi_processor_power acpi_state_table __initdata;
+
+/**
+ * intel_idle_cst_usable - Check if the _CST information can be used.
+ *
+ * Check if all of the C-states listed by _CST in the max_cstate range are
+ * ACPI_CSTATE_FFH, which means that they should be entered via MWAIT.
  */
-static int __init intel_idle_probe(void)
+static bool __init intel_idle_cst_usable(void)
 {
-	unsigned int eax, ebx, ecx;
-	const struct x86_cpu_id *id;
+	int cstate, limit;
 
-	if (max_cstate == 0) {
-		pr_debug("disabled\n");
-		return -EPERM;
-	}
+	limit = min_t(int, min_t(int, CPUIDLE_STATE_MAX, max_cstate + 1),
+		      acpi_state_table.count);
 
-	id = x86_match_cpu(intel_idle_ids);
-	if (!id) {
-		if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
-		    boot_cpu_data.x86 == 6)
-			pr_debug("does not run on family %d model %d\n",
-				 boot_cpu_data.x86, boot_cpu_data.x86_model);
-		return -ENODEV;
+	for (cstate = 1; cstate < limit; cstate++) {
+		struct acpi_processor_cx *cx = &acpi_state_table.states[cstate];
+
+		if (cx->entry_method != ACPI_CSTATE_FFH)
+			return false;
 	}
 
-	if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
-		pr_debug("Please enable MWAIT in BIOS SETUP\n");
-		return -ENODEV;
+	return true;
+}
+
+static bool __init intel_idle_acpi_cst_extract(void)
+{
+	unsigned int cpu;
+
+	if (no_acpi) {
+		pr_debug("Not allowed to use ACPI _CST\n");
+		return false;
 	}
 
-	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
-		return -ENODEV;
+	for_each_possible_cpu(cpu) {
+		struct acpi_processor *pr = per_cpu(processors, cpu);
 
-	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
+		if (!pr)
+			continue;
 
-	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
-	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
-	    !mwait_substates)
-			return -ENODEV;
+		if (acpi_processor_evaluate_cst(pr->handle, cpu, &acpi_state_table))
+			continue;
 
-	pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
+		acpi_state_table.count++;
 
-	icpu = (const struct idle_cpu *)id->driver_data;
-	cpuidle_state_table = icpu->state_table;
+		if (!intel_idle_cst_usable())
+			continue;
 
-	pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
-		 boot_cpu_data.x86_model);
+		if (!acpi_processor_claim_cst_control()) {
+			acpi_state_table.count = 0;
+			return false;
+		}
 
-	return 0;
+		return true;
+	}
+
+	pr_debug("ACPI _CST not found or not usable\n");
+	return false;
 }
 
-/*
- * intel_idle_cpuidle_devices_uninit()
- * Unregisters the cpuidle devices.
- */
-static void intel_idle_cpuidle_devices_uninit(void)
+static void __init intel_idle_init_cstates_acpi(struct cpuidle_driver *drv)
 {
-	int i;
-	struct cpuidle_device *dev;
+	int cstate, limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
+
+	/*
+	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
+	 * the interesting states are ACPI_CSTATE_FFH.
+	 */
+	for (cstate = 1; cstate < limit; cstate++) {
+		struct acpi_processor_cx *cx;
+		struct cpuidle_state *state;
 
-	for_each_online_cpu(i) {
-		dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
-		cpuidle_unregister_device(dev);
+		if (intel_idle_max_cstate_reached(cstate))
+			break;
+
+		cx = &acpi_state_table.states[cstate];
+
+		state = &drv->states[drv->state_count++];
+
+		snprintf(state->name, CPUIDLE_NAME_LEN, "C%d_ACPI", cstate);
+		strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
+		state->exit_latency = cx->latency;
+		/*
+		 * For C1-type C-states use the same number for both the exit
+		 * latency and target residency, because that is the case for
+		 * C1 in the majority of the static C-states tables above.
+		 * For the other types of C-states, however, set the target
+		 * residency to 3 times the exit latency which should lead to
+		 * a reasonable balance between energy-efficiency and
+		 * performance in the majority of interesting cases.
+		 */
+		state->target_residency = cx->latency;
+		if (cx->type > ACPI_STATE_C1)
+			state->target_residency *= 3;
+
+		state->flags = MWAIT2flg(cx->address);
+		if (cx->type > ACPI_STATE_C2)
+			state->flags |= CPUIDLE_FLAG_TLB_FLUSHED;
+
+		state->enter = intel_idle;
+		state->enter_s2idle = intel_idle_s2idle;
 	}
 }
 
+static bool __init intel_idle_off_by_default(u32 mwait_hint)
+{
+	int cstate, limit;
+
+	/*
+	 * If there are no _CST C-states, do not disable any C-states by
+	 * default.
+	 */
+	if (!acpi_state_table.count)
+		return false;
+
+	limit = min_t(int, CPUIDLE_STATE_MAX, acpi_state_table.count);
+	/*
+	 * If limit > 0, intel_idle_cst_usable() has returned 'true', so all of
+	 * the interesting states are ACPI_CSTATE_FFH.
+	 */
+	for (cstate = 1; cstate < limit; cstate++) {
+		if (acpi_state_table.states[cstate].address == mwait_hint)
+			return false;
+	}
+	return true;
+}
+#else /* !CONFIG_ACPI_PROCESSOR_CSTATE */
+static inline bool intel_idle_acpi_cst_extract(void) { return false; }
+static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { }
+static inline bool intel_idle_off_by_default(u32 mwait_hint) { return false; }
+#endif /* !CONFIG_ACPI_PROCESSOR_CSTATE */
+
 /*
  * ivt_idle_state_table_update(void)
  *
  * Tune IVT multi-socket targets
  * Assumption: num_sockets == (max_package_num + 1)
  */
-static void ivt_idle_state_table_update(void)
+static void __init ivt_idle_state_table_update(void)
 {
 	/* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
 	int cpu, package_num, num_sockets = 1;
@@ -1187,15 +1292,17 @@ static void ivt_idle_state_table_update(void)
 	/* else, 1 and 2 socket systems use default ivt_cstates */
 }
 
-/*
- * Translate IRTL (Interrupt Response Time Limit) MSR to usec
+/**
+ * irtl_2_usec - IRTL to microseconds conversion.
+ * @irtl: IRTL MSR value.
+ *
+ * Translate the IRTL (Interrupt Response Time Limit) MSR value to microseconds.
  */
-
-static unsigned int irtl_ns_units[] = {
-	1, 32, 1024, 32768, 1048576, 33554432, 0, 0 };
-
-static unsigned long long irtl_2_usec(unsigned long long irtl)
+static unsigned long long __init irtl_2_usec(unsigned long long irtl)
 {
+	static const unsigned int irtl_ns_units[] __initconst = {
+		1, 32, 1024, 32768, 1048576, 33554432, 0, 0
+	};
 	unsigned long long ns;
 
 	if (!irtl)
@@ -1203,15 +1310,16 @@ static unsigned long long irtl_2_usec(unsigned long long irtl)
 
 	ns = irtl_ns_units[(irtl >> 10) & 0x7];
 
-	return div64_u64((irtl & 0x3FF) * ns, 1000);
+	return div_u64((irtl & 0x3FF) * ns, NSEC_PER_USEC);
 }
+
 /*
  * bxt_idle_state_table_update(void)
  *
  * On BXT, we trust the IRTL to show the definitive maximum latency
  * We use the same value for target_residency.
  */
-static void bxt_idle_state_table_update(void)
+static void __init bxt_idle_state_table_update(void)
 {
 	unsigned long long msr;
 	unsigned int usec;
@@ -1258,7 +1366,7 @@ static void bxt_idle_state_table_update(void)
  * On SKL-H (model 0x5e) disable C8 and C9 if:
  * C10 is enabled and SGX disabled
  */
-static void sklh_idle_state_table_update(void)
+static void __init sklh_idle_state_table_update(void)
 {
 	unsigned long long msr;
 	unsigned int eax, ebx, ecx, edx;
@@ -1294,16 +1402,28 @@ static void sklh_idle_state_table_update(void)
 	skl_cstates[5].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C8-SKL */
 	skl_cstates[6].flags |= CPUIDLE_FLAG_UNUSABLE;	/* C9-SKL */
 }
-/*
- * intel_idle_state_table_update()
- *
- * Update the default state_table for this CPU-id
- */
 
-static void intel_idle_state_table_update(void)
+static bool __init intel_idle_verify_cstate(unsigned int mwait_hint)
 {
-	switch (boot_cpu_data.x86_model) {
+	unsigned int mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint) + 1;
+	unsigned int num_substates = (mwait_substates >> mwait_cstate * 4) &
+					MWAIT_SUBSTATE_MASK;
+
+	/* Ignore the C-state if there are NO sub-states in CPUID for it. */
+	if (num_substates == 0)
+		return false;
+
+	if (mwait_cstate > 2 && !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
+		mark_tsc_unstable("TSC halts in idle states deeper than C2");
 
+	return true;
+}
+
+static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
+{
+	int cstate;
+
+	switch (boot_cpu_data.x86_model) {
 	case INTEL_FAM6_IVYBRIDGE_X:
 		ivt_idle_state_table_update();
 		break;
@@ -1315,62 +1435,36 @@ static void intel_idle_state_table_update(void)
 		sklh_idle_state_table_update();
 		break;
 	}
-}
-
-/*
- * intel_idle_cpuidle_driver_init()
- * allocate, initialize cpuidle_states
- */
-static void __init intel_idle_cpuidle_driver_init(void)
-{
-	int cstate;
-	struct cpuidle_driver *drv = &intel_idle_driver;
-
-	intel_idle_state_table_update();
-
-	cpuidle_poll_state_init(drv);
-	drv->state_count = 1;
 
 	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
-		int num_substates, mwait_hint, mwait_cstate;
+		unsigned int mwait_hint;
 
-		if ((cpuidle_state_table[cstate].enter == NULL) &&
-		    (cpuidle_state_table[cstate].enter_s2idle == NULL))
+		if (intel_idle_max_cstate_reached(cstate))
 			break;
 
-		if (cstate + 1 > max_cstate) {
-			pr_info("max_cstate %d reached\n", max_cstate);
+		if (!cpuidle_state_table[cstate].enter &&
+		    !cpuidle_state_table[cstate].enter_s2idle)
 			break;
-		}
-
-		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
-		mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint);
-
-		/* number of sub-states for this state in CPUID.MWAIT */
-		num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4))
-					& MWAIT_SUBSTATE_MASK;
-
-		/* if NO sub-states for this state in CPUID, skip it */
-		if (num_substates == 0)
-			continue;
 
-		/* if state marked as disabled, skip it */
+		/* If marked as unusable, skip this state. */
 		if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {
 			pr_debug("state %s is disabled\n",
 				 cpuidle_state_table[cstate].name);
 			continue;
 		}
 
+		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
+		if (!intel_idle_verify_cstate(mwait_hint))
+			continue;
 
-		if (((mwait_cstate + 1) > 2) &&
-			!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
-			mark_tsc_unstable("TSC halts in idle"
-					" states deeper than C2");
+		/* Structure copy. */
+		drv->states[drv->state_count] = cpuidle_state_table[cstate];
 
-		drv->states[drv->state_count] =	/* structure copy */
-			cpuidle_state_table[cstate];
+		if (icpu->use_acpi && intel_idle_off_by_default(mwait_hint) &&
+		    !(cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_ALWAYS_ENABLE))
+			drv->states[drv->state_count].flags |= CPUIDLE_FLAG_OFF;
 
-		drv->state_count += 1;
+		drv->state_count++;
 	}
 
 	if (icpu->byt_auto_demotion_disable_flag) {
@@ -1379,6 +1473,38 @@ static void __init intel_idle_cpuidle_driver_init(void)
 	}
 }
 
+/*
+ * intel_idle_cpuidle_driver_init()
+ * allocate, initialize cpuidle_states
+ */
+static void __init intel_idle_cpuidle_driver_init(struct cpuidle_driver *drv)
+{
+	cpuidle_poll_state_init(drv);
+	drv->state_count = 1;
+
+	if (icpu)
+		intel_idle_init_cstates_icpu(drv);
+	else
+		intel_idle_init_cstates_acpi(drv);
+}
+
+static void auto_demotion_disable(void)
+{
+	unsigned long long msr_bits;
+
+	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
+	msr_bits &= ~(icpu->auto_demotion_disable_flags);
+	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
+}
+
+static void c1e_promotion_disable(void)
+{
+	unsigned long long msr_bits;
+
+	rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
+	msr_bits &= ~0x2;
+	wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
+}
 
 /*
  * intel_idle_cpu_init()
@@ -1397,6 +1523,9 @@ static int intel_idle_cpu_init(unsigned int cpu)
 		return -EIO;
 	}
 
+	if (!icpu)
+		return 0;
+
 	if (icpu->auto_demotion_disable_flags)
 		auto_demotion_disable();
 
@@ -1411,7 +1540,7 @@ static int intel_idle_cpu_online(unsigned int cpu)
 	struct cpuidle_device *dev;
 
 	if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
-		__setup_broadcast_timer(true);
+		tick_broadcast_enable();
 
 	/*
 	 * Some systems can hotplug a cpu at runtime after
@@ -1425,23 +1554,74 @@ static int intel_idle_cpu_online(unsigned int cpu)
 	return 0;
 }
 
+/**
+ * intel_idle_cpuidle_devices_uninit - Unregister all cpuidle devices.
+ */
+static void __init intel_idle_cpuidle_devices_uninit(void)
+{
+	int i;
+
+	for_each_online_cpu(i)
+		cpuidle_unregister_device(per_cpu_ptr(intel_idle_cpuidle_devices, i));
+}
+
 static int __init intel_idle_init(void)
 {
+	const struct x86_cpu_id *id;
+	unsigned int eax, ebx, ecx;
 	int retval;
 
 	/* Do not load intel_idle at all for now if idle= is passed */
 	if (boot_option_idle_override != IDLE_NO_OVERRIDE)
 		return -ENODEV;
 
-	retval = intel_idle_probe();
-	if (retval)
-		return retval;
+	if (max_cstate == 0) {
+		pr_debug("disabled\n");
+		return -EPERM;
+	}
+
+	id = x86_match_cpu(intel_idle_ids);
+	if (id) {
+		if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
+			pr_debug("Please enable MWAIT in BIOS SETUP\n");
+			return -ENODEV;
+		}
+	} else {
+		id = x86_match_cpu(intel_mwait_ids);
+		if (!id)
+			return -ENODEV;
+	}
+
+	if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
+		return -ENODEV;
+
+	cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
+
+	if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
+	    !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
+	    !mwait_substates)
+			return -ENODEV;
+
+	pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
+
+	icpu = (const struct idle_cpu *)id->driver_data;
+	if (icpu) {
+		cpuidle_state_table = icpu->state_table;
+		if (icpu->use_acpi)
+			intel_idle_acpi_cst_extract();
+	} else if (!intel_idle_acpi_cst_extract()) {
+		return -ENODEV;
+	}
+
+	pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
+		 boot_cpu_data.x86_model);
 
 	intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
-	if (intel_idle_cpuidle_devices == NULL)
+	if (!intel_idle_cpuidle_devices)
 		return -ENOMEM;
 
-	intel_idle_cpuidle_driver_init();
+	intel_idle_cpuidle_driver_init(&intel_idle_driver);
+
 	retval = cpuidle_register_driver(&intel_idle_driver);
 	if (retval) {
 		struct cpuidle_driver *drv = cpuidle_get_driver();