Merge branches 'acpi-processor', 'acpi-cppc', 'acpi-apei' and 'acpi-sleep'

* acpi-processor:
  ACPI: enable ACPI_PROCESSOR_IDLE on ARM64
  arm64: add support for ACPI Low Power Idle(LPI)
  drivers: firmware: psci: initialise idle states using ACPI LPI
  cpuidle: introduce CPU_PM_CPU_IDLE_ENTER macro for ARM{32, 64}
  arm64: cpuidle: drop __init section marker to arm_cpuidle_init
  ACPI / processor_idle: Add support for Low Power Idle(LPI) states
  ACPI / processor_idle: introduce ACPI_PROCESSOR_CSTATE

* acpi-cppc:
  mailbox: pcc: Add PCC request and free channel declarations
  ACPI / CPPC: Prevent cpc_desc_ptr points to the invalid data
  ACPI: CPPC: Return error if _CPC is invalid on a CPU

* acpi-apei:
  ACPI / APEI: Add Boot Error Record Table (BERT) support
  ACPI / einj: Make error paths more talkative
  ACPI / einj: Convert EINJ_PFX to proper pr_fmt

* acpi-sleep:
  ACPI: Execute _PTS before system reboot

Documentation/kernel-parameters.txt

@@ -582,6 +582,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 
 	bootmem_debug	[KNL] Enable bootmem allocator debug messages.
 
+	bert_disable	[ACPI]
+			Disable BERT OS support on buggy BIOSes.
+
 	bttv.card=	[HW,V4L] bttv (bt848 + bt878 based grabber cards)
 	bttv.radio=	Most important insmod options are available as
 			kernel args too.

arch/arm64/kernel/cpuidle.c

@@ -9,13 +9,16 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/acpi.h>
+#include <linux/cpuidle.h>
+#include <linux/cpu_pm.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 
 #include <asm/cpuidle.h>
 #include <asm/cpu_ops.h>
 
-int __init arm_cpuidle_init(unsigned int cpu)
+int arm_cpuidle_init(unsigned int cpu)
 {
 	int ret = -EOPNOTSUPP;
 
@@ -39,3 +42,18 @@ int arm_cpuidle_suspend(int index)
 
 	return cpu_ops[cpu]->cpu_suspend(index);
 }
+
+#ifdef CONFIG_ACPI
+
+#include <acpi/processor.h>
+
+int acpi_processor_ffh_lpi_probe(unsigned int cpu)
+{
+	return arm_cpuidle_init(cpu);
+}
+
+int acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
+{
+	return CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, lpi->index);
+}
+#endif

drivers/acpi/Kconfig

@@ -213,6 +213,10 @@ config ACPI_CPU_FREQ_PSS
 	bool
 	select THERMAL
 
+config ACPI_PROCESSOR_CSTATE
+	def_bool y
+	depends on IA64 || X86
+
 config ACPI_PROCESSOR_IDLE
 	bool
 	select CPU_IDLE
@@ -234,7 +238,7 @@ config ACPI_CPPC_LIB
 config ACPI_PROCESSOR
 	tristate "Processor"
 	depends on X86 || IA64 || ARM64
-	select ACPI_PROCESSOR_IDLE if X86 || IA64
+	select ACPI_PROCESSOR_IDLE
 	select ACPI_CPU_FREQ_PSS if X86 || IA64
 	default y
 	help

drivers/acpi/apei/Makefile

@@ -3,4 +3,4 @@ obj-$(CONFIG_ACPI_APEI_GHES)	+= ghes.o
 obj-$(CONFIG_ACPI_APEI_EINJ)	+= einj.o
 obj-$(CONFIG_ACPI_APEI_ERST_DEBUG) += erst-dbg.o
 
-apei-y := apei-base.o hest.o erst.o
+apei-y := apei-base.o hest.o erst.o bert.o

drivers/acpi/apei/apei-internal.h

@@ -1,6 +1,6 @@
 /*
  * apei-internal.h - ACPI Platform Error Interface internal
- * definations.
+ * definitions.
  */
 
 #ifndef APEI_INTERNAL_H

drivers/acpi/apei/bert.c

@@ -0,0 +1,150 @@
+/*
+ * APEI Boot Error Record Table (BERT) support
+ *
+ * Copyright 2011 Intel Corp.
+ *   Author: Huang Ying <ying.huang@intel.com>
+ *
+ * Under normal circumstances, when a hardware error occurs, the error
+ * handler receives control and processes the error. This gives OSPM a
+ * chance to process the error condition, report it, and optionally attempt
+ * recovery. In some cases, the system is unable to process an error.
+ * For example, system firmware or a management controller may choose to
+ * reset the system or the system might experience an uncontrolled crash
+ * or reset.The boot error source is used to report unhandled errors that
+ * occurred in a previous boot. This mechanism is described in the BERT
+ * table.
+ *
+ * For more information about BERT, please refer to ACPI Specification
+ * version 4.0, section 17.3.1
+ *
+ * This file is licensed under GPLv2.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <linux/io.h>
+
+#include "apei-internal.h"
+
+#undef pr_fmt
+#define pr_fmt(fmt) "BERT: " fmt
+
+static int bert_disable;
+
+static void __init bert_print_all(struct acpi_bert_region *region,
+				  unsigned int region_len)
+{
+	struct acpi_hest_generic_status *estatus =
+		(struct acpi_hest_generic_status *)region;
+	int remain = region_len;
+	u32 estatus_len;
+
+	if (!estatus->block_status)
+		return;
+
+	while (remain > sizeof(struct acpi_bert_region)) {
+		if (cper_estatus_check(estatus)) {
+			pr_err(FW_BUG "Invalid error record.\n");
+			return;
+		}
+
+		estatus_len = cper_estatus_len(estatus);
+		if (remain < estatus_len) {
+			pr_err(FW_BUG "Truncated status block (length: %u).\n",
+			       estatus_len);
+			return;
+		}
+
+		pr_info_once("Error records from previous boot:\n");
+
+		cper_estatus_print(KERN_INFO HW_ERR, estatus);
+
+		/*
+		 * Because the boot error source is "one-time polled" type,
+		 * clear Block Status of current Generic Error Status Block,
+		 * once it's printed.
+		 */
+		estatus->block_status = 0;
+
+		estatus = (void *)estatus + estatus_len;
+		/* No more error records. */
+		if (!estatus->block_status)
+			return;
+
+		remain -= estatus_len;
+	}
+}
+
+static int __init setup_bert_disable(char *str)
+{
+	bert_disable = 1;
+
+	return 0;
+}
+__setup("bert_disable", setup_bert_disable);
+
+static int __init bert_check_table(struct acpi_table_bert *bert_tab)
+{
+	if (bert_tab->header.length < sizeof(struct acpi_table_bert) ||
+	    bert_tab->region_length < sizeof(struct acpi_bert_region))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int __init bert_init(void)
+{
+	struct acpi_bert_region *boot_error_region;
+	struct acpi_table_bert *bert_tab;
+	unsigned int region_len;
+	acpi_status status;
+	int rc = 0;
+
+	if (acpi_disabled)
+		return 0;
+
+	if (bert_disable) {
+		pr_info("Boot Error Record Table support is disabled.\n");
+		return 0;
+	}
+
+	status = acpi_get_table(ACPI_SIG_BERT, 0, (struct acpi_table_header **)&bert_tab);
+	if (status == AE_NOT_FOUND)
+		return 0;
+
+	if (ACPI_FAILURE(status)) {
+		pr_err("get table failed, %s.\n", acpi_format_exception(status));
+		return -EINVAL;
+	}
+
+	rc = bert_check_table(bert_tab);
+	if (rc) {
+		pr_err(FW_BUG "table invalid.\n");
+		return rc;
+	}
+
+	region_len = bert_tab->region_length;
+	if (!request_mem_region(bert_tab->address, region_len, "APEI BERT")) {
+		pr_err("Can't request iomem region <%016llx-%016llx>.\n",
+		       (unsigned long long)bert_tab->address,
+		       (unsigned long long)bert_tab->address + region_len - 1);
+		return -EIO;
+	}
+
+	boot_error_region = ioremap_cache(bert_tab->address, region_len);
+	if (boot_error_region) {
+		bert_print_all(boot_error_region, region_len);
+		iounmap(boot_error_region);
+	} else {
+		rc = -ENOMEM;
+	}
+
+	release_mem_region(bert_tab->address, region_len);
+
+	return rc;
+}
+
+late_initcall(bert_init);

drivers/acpi/apei/einj.c

@@ -33,7 +33,8 @@
 
 #include "apei-internal.h"
 
-#define EINJ_PFX "EINJ: "
+#undef pr_fmt
+#define pr_fmt(fmt) "EINJ: " fmt
 
 #define SPIN_UNIT		100			/* 100ns */
 /* Firmware should respond within 1 milliseconds */
@@ -179,8 +180,7 @@ static int einj_get_available_error_type(u32 *type)
 static int einj_timedout(u64 *t)
 {
 	if ((s64)*t < SPIN_UNIT) {
-		pr_warning(FW_WARN EINJ_PFX
-			   "Firmware does not respond in time\n");
+		pr_warning(FW_WARN "Firmware does not respond in time\n");
 		return 1;
 	}
 	*t -= SPIN_UNIT;
@@ -307,8 +307,7 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
 	r = request_mem_region(trigger_paddr, sizeof(*trigger_tab),
 			       "APEI EINJ Trigger Table");
 	if (!r) {
-		pr_err(EINJ_PFX
-	"Can not request [mem %#010llx-%#010llx] for Trigger table\n",
+		pr_err("Can not request [mem %#010llx-%#010llx] for Trigger table\n",
 		       (unsigned long long)trigger_paddr,
 		       (unsigned long long)trigger_paddr +
 			    sizeof(*trigger_tab) - 1);
@@ -316,13 +315,12 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
 	}
 	trigger_tab = ioremap_cache(trigger_paddr, sizeof(*trigger_tab));
 	if (!trigger_tab) {
-		pr_err(EINJ_PFX "Failed to map trigger table!\n");
+		pr_err("Failed to map trigger table!\n");
 		goto out_rel_header;
 	}
 	rc = einj_check_trigger_header(trigger_tab);
 	if (rc) {
-		pr_warning(FW_BUG EINJ_PFX
-			   "The trigger error action table is invalid\n");
+		pr_warning(FW_BUG "Invalid trigger error action table.\n");
 		goto out_rel_header;
 	}
 
@@ -336,8 +334,7 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
 			       table_size - sizeof(*trigger_tab),
 			       "APEI EINJ Trigger Table");
 	if (!r) {
-		pr_err(EINJ_PFX
-"Can not request [mem %#010llx-%#010llx] for Trigger Table Entry\n",
+		pr_err("Can not request [mem %#010llx-%#010llx] for Trigger Table Entry\n",
 		       (unsigned long long)trigger_paddr + sizeof(*trigger_tab),
 		       (unsigned long long)trigger_paddr + table_size - 1);
 		goto out_rel_header;
@@ -345,7 +342,7 @@ static int __einj_error_trigger(u64 trigger_paddr, u32 type,
 	iounmap(trigger_tab);
 	trigger_tab = ioremap_cache(trigger_paddr, table_size);
 	if (!trigger_tab) {
-		pr_err(EINJ_PFX "Failed to map trigger table!\n");
+		pr_err("Failed to map trigger table!\n");
 		goto out_rel_entry;
 	}
 	trigger_entry = (struct acpi_whea_header *)
@@ -695,34 +692,42 @@ static int __init einj_init(void)
 	struct dentry *fentry;
 	struct apei_exec_context ctx;
 
-	if (acpi_disabled)
+	if (acpi_disabled) {
+		pr_warn("ACPI disabled.\n");
 		return -ENODEV;
+	}
 
 	status = acpi_get_table(ACPI_SIG_EINJ, 0,
 				(struct acpi_table_header **)&einj_tab);
-	if (status == AE_NOT_FOUND)
+	if (status == AE_NOT_FOUND) {
+		pr_warn("EINJ table not found.\n");
 		return -ENODEV;
+	}
 	else if (ACPI_FAILURE(status)) {
-		const char *msg = acpi_format_exception(status);
-		pr_err(EINJ_PFX "Failed to get table, %s\n", msg);
+		pr_err("Failed to get EINJ table: %s\n",
+				acpi_format_exception(status));
 		return -EINVAL;
 	}
 
 	rc = einj_check_table(einj_tab);
 	if (rc) {
-		pr_warning(FW_BUG EINJ_PFX "EINJ table is invalid\n");
+		pr_warn(FW_BUG "Invalid EINJ table.n");
 		return -EINVAL;
 	}
 
 	rc = -ENOMEM;
 	einj_debug_dir = debugfs_create_dir("einj", apei_get_debugfs_dir());
-	if (!einj_debug_dir)
+	if (!einj_debug_dir) {
+		pr_err("Error creating debugfs node.\n");
 		goto err_cleanup;
+	}
+
 	fentry = debugfs_create_file("available_error_type", S_IRUSR,
 				     einj_debug_dir, NULL,
 				     &available_error_type_fops);
 	if (!fentry)
 		goto err_cleanup;
+
 	fentry = debugfs_create_file("error_type", S_IRUSR | S_IWUSR,
 				     einj_debug_dir, NULL, &error_type_fops);
 	if (!fentry)
@@ -735,14 +740,22 @@ static int __init einj_init(void)
 	apei_resources_init(&einj_resources);
 	einj_exec_ctx_init(&ctx);
 	rc = apei_exec_collect_resources(&ctx, &einj_resources);
-	if (rc)
+	if (rc) {
+		pr_err("Error collecting EINJ resources.\n");
 		goto err_fini;
+	}
+
 	rc = apei_resources_request(&einj_resources, "APEI EINJ");
-	if (rc)
+	if (rc) {
+		pr_err("Error requesting memory/port resources.\n");
 		goto err_fini;
+	}
+
 	rc = apei_exec_pre_map_gars(&ctx);
-	if (rc)
+	if (rc) {
+		pr_err("Error pre-mapping GARs.\n");
 		goto err_release;
+	}
 
 	rc = -ENOMEM;
 	einj_param = einj_get_parameter_address();
@@ -787,7 +800,7 @@ static int __init einj_init(void)
 			goto err_unmap;
 	}
 
-	pr_info(EINJ_PFX "Error INJection is initialized.\n");
+	pr_info("Error INJection is initialized.\n");
 
 	return 0;
 
@@ -798,6 +811,7 @@ err_unmap:
 			sizeof(struct einj_parameter);
 
 		acpi_os_unmap_iomem(einj_param, size);
+		pr_err("Error creating param extension debugfs nodes.\n");
 	}
 	apei_exec_post_unmap_gars(&ctx);
 err_release:
@@ -805,6 +819,7 @@ err_release:
 err_fini:
 	apei_resources_fini(&einj_resources);
 err_cleanup:
+	pr_err("Error creating primary debugfs nodes.\n");
 	debugfs_remove_recursive(einj_debug_dir);
 
 	return rc;

drivers/acpi/bus.c

@@ -300,6 +300,14 @@ 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)
 {
@@ -320,6 +328,7 @@ 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;
@@ -327,9 +336,12 @@ 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 */

drivers/acpi/cppc_acpi.c

@@ -299,8 +299,10 @@ int acpi_get_psd_map(struct cpudata **all_cpu_data)
 			continue;
 
 		cpc_ptr = per_cpu(cpc_desc_ptr, i);
-		if (!cpc_ptr)
-			continue;
+		if (!cpc_ptr) {
+			retval = -EFAULT;
+			goto err_ret;
+		}
 
 		pdomain = &(cpc_ptr->domain_info);
 		cpumask_set_cpu(i, pr->shared_cpu_map);
@@ -322,8 +324,10 @@ int acpi_get_psd_map(struct cpudata **all_cpu_data)
 				continue;
 
 			match_cpc_ptr = per_cpu(cpc_desc_ptr, j);
-			if (!match_cpc_ptr)
-				continue;
+			if (!match_cpc_ptr) {
+				retval = -EFAULT;
+				goto err_ret;
+			}
 
 			match_pdomain = &(match_cpc_ptr->domain_info);
 			if (match_pdomain->domain != pdomain->domain)
@@ -353,8 +357,10 @@ int acpi_get_psd_map(struct cpudata **all_cpu_data)
 				continue;
 
 			match_cpc_ptr = per_cpu(cpc_desc_ptr, j);
-			if (!match_cpc_ptr)
-				continue;
+			if (!match_cpc_ptr) {
+				retval = -EFAULT;
+				goto err_ret;
+			}
 
 			match_pdomain = &(match_cpc_ptr->domain_info);
 			if (match_pdomain->domain != pdomain->domain)
@@ -595,9 +601,6 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 	/* Store CPU Logical ID */
 	cpc_ptr->cpu_id = pr->id;
 
-	/* Plug it into this CPUs CPC descriptor. */
-	per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr;
-
 	/* Parse PSD data for this CPU */
 	ret = acpi_get_psd(cpc_ptr, handle);
 	if (ret)
@@ -610,6 +613,9 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 			goto out_free;
 	}
 
+	/* Plug PSD data into this CPUs CPC descriptor. */
+	per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr;
+
 	/* Everything looks okay */
 	pr_debug("Parsed CPC struct for CPU: %d\n", pr->id);
 

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;

drivers/acpi/processor_idle.c

@@ -59,6 +59,12 @@ module_param(latency_factor, uint, 0644);
 
 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
 
+struct cpuidle_driver acpi_idle_driver = {
+	.name =		"acpi_idle",
+	.owner =	THIS_MODULE,
+};
+
+#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
 static
 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
 
@@ -297,7 +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;
 
@@ -570,7 +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;
@@ -804,36 +809,12 @@ static void acpi_idle_enter_freeze(struct cpuidle_device *dev,
 	acpi_idle_do_entry(cx);
 }
 
-struct cpuidle_driver acpi_idle_driver = {
-	.name =		"acpi_idle",
-	.owner =	THIS_MODULE,
-};
-
-/**
- * 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;
 
@@ -856,31 +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;
 
@@ -892,7 +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;
@@ -925,6 +888,450 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
 	return 0;
 }
 
+static inline void acpi_processor_cstate_first_run_checks(void)
+{
+	acpi_status status;
+	static int first_run;
+
+	if (first_run)
+		return;
+	dmi_check_system(processor_power_dmi_table);
+	max_cstate = acpi_processor_cstate_check(max_cstate);
+	if (max_cstate < ACPI_C_STATES_MAX)
+		pr_notice("ACPI: processor limited to max C-state %d\n",
+			  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"));
+	}
+}
+#else
+
+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_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_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;
@@ -933,18 +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();
@@ -952,7 +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;
@@ -961,9 +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;
 
@@ -1000,7 +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);
 			}
 		}
@@ -1015,35 +1416,16 @@ static int acpi_processor_registered;
 
 int acpi_processor_power_init(struct acpi_processor *pr)
 {
-	acpi_status status;
 	int retval;
 	struct cpuidle_device *dev;
-	static int first_run;
 
 	if (disabled_by_idle_boot_param())
 		return 0;
 
-	if (!first_run) {
-		dmi_check_system(processor_power_dmi_table);
-		max_cstate = acpi_processor_cstate_check(max_cstate);
-		if (max_cstate < ACPI_C_STATES_MAX)
-			printk(KERN_NOTICE
-			       "ACPI: processor limited to max C-state %d\n",
-			       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"));
-		}
-	}
+	acpi_processor_cstate_first_run_checks();
 
-	acpi_processor_get_power_info(pr);
-	pr->flags.power_setup_done = 1;
+	if (!acpi_processor_get_power_info(pr))
+		pr->flags.power_setup_done = 1;
 
 	/*
 	 * Install the idle handler if processor power management is supported.
@@ -1066,7 +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

drivers/acpi/sleep.c

@@ -47,15 +47,32 @@ static void acpi_sleep_tts_switch(u32 acpi_state)
 	}
 }
 
-static int tts_notify_reboot(struct notifier_block *this,
+static void acpi_sleep_pts_switch(u32 acpi_state)
+{
+	acpi_status status;
+
+	status = acpi_execute_simple_method(NULL, "\\_PTS", acpi_state);
+	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+		/*
+		 * OS can't evaluate the _PTS object correctly. Some warning
+		 * message will be printed. But it won't break anything.
+		 */
+		printk(KERN_NOTICE "Failure in evaluating _PTS object\n");
+	}
+}
+
+static int sleep_notify_reboot(struct notifier_block *this,
 			unsigned long code, void *x)
 {
 	acpi_sleep_tts_switch(ACPI_STATE_S5);
+
+	acpi_sleep_pts_switch(ACPI_STATE_S5);
+
 	return NOTIFY_DONE;
 }
 
-static struct notifier_block tts_notifier = {
-	.notifier_call	= tts_notify_reboot,
+static struct notifier_block sleep_notifier = {
+	.notifier_call	= sleep_notify_reboot,
 	.next		= NULL,
 	.priority	= 0,
 };
@@ -899,9 +916,9 @@ int __init acpi_sleep_init(void)
 	pr_info(PREFIX "(supports%s)\n", supported);
 
 	/*
-	 * Register the tts_notifier to reboot notifier list so that the _TTS
-	 * object can also be evaluated when the system enters S5.
+	 * Register the sleep_notifier to reboot notifier list so that the _TTS
+	 * and _PTS object can also be evaluated when the system enters S5.
 	 */
-	register_reboot_notifier(&tts_notifier);
+	register_reboot_notifier(&sleep_notifier);
 	return 0;
 }

drivers/cpuidle/cpuidle-arm.c

@@ -36,26 +36,12 @@
 static int arm_enter_idle_state(struct cpuidle_device *dev,
 				struct cpuidle_driver *drv, int idx)
 {
-	int ret;
-
-	if (!idx) {
-		cpu_do_idle();
-		return idx;
-	}
-
-	ret = cpu_pm_enter();
-	if (!ret) {
-		/*
-		 * Pass idle state index to cpu_suspend which in turn will
-		 * call the CPU ops suspend protocol with idle index as a
-		 * parameter.
-		 */
-		ret = arm_cpuidle_suspend(idx);
-
-		cpu_pm_exit();
-	}
-
-	return ret ? -1 : idx;
+	/*
+	 * Pass idle state index to arm_cpuidle_suspend which in turn
+	 * will call the CPU ops suspend protocol with idle index as a
+	 * parameter.
+	 */
+	return CPU_PM_CPU_IDLE_ENTER(arm_cpuidle_suspend, idx);
 }
 
 static struct cpuidle_driver arm_idle_driver = {

drivers/firmware/psci.c

@@ -13,6 +13,7 @@
 
 #define pr_fmt(fmt) "psci: " fmt
 
+#include <linux/acpi.h>
 #include <linux/arm-smccc.h>
 #include <linux/cpuidle.h>
 #include <linux/errno.h>
@@ -256,13 +257,6 @@ static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
 	u32 *psci_states;
 	struct device_node *state_node;
 
-	/*
-	 * If the PSCI cpu_suspend function hook has not been initialized
-	 * idle states must not be enabled, so bail out
-	 */
-	if (!psci_ops.cpu_suspend)
-		return -EOPNOTSUPP;
-
 	/* Count idle states */
 	while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
 					      count))) {
@@ -310,11 +304,69 @@ free_mem:
 	return ret;
 }
 
+#ifdef CONFIG_ACPI
+#include <acpi/processor.h>
+
+static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu)
+{
+	int i, count;
+	u32 *psci_states;
+	struct acpi_lpi_state *lpi;
+	struct acpi_processor *pr = per_cpu(processors, cpu);
+
+	if (unlikely(!pr || !pr->flags.has_lpi))
+		return -EINVAL;
+
+	count = pr->power.count - 1;
+	if (count <= 0)
+		return -ENODEV;
+
+	psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
+	if (!psci_states)
+		return -ENOMEM;
+
+	for (i = 0; i < count; i++) {
+		u32 state;
+
+		lpi = &pr->power.lpi_states[i + 1];
+		/*
+		 * Only bits[31:0] represent a PSCI power_state while
+		 * bits[63:32] must be 0x0 as per ARM ACPI FFH Specification
+		 */
+		state = lpi->address;
+		if (!psci_power_state_is_valid(state)) {
+			pr_warn("Invalid PSCI power state %#x\n", state);
+			kfree(psci_states);
+			return -EINVAL;
+		}
+		psci_states[i] = state;
+	}
+	/* Idle states parsed correctly, initialize per-cpu pointer */
+	per_cpu(psci_power_state, cpu) = psci_states;
+	return 0;
+}
+#else
+static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu)
+{
+	return -EINVAL;
+}
+#endif
+
 int psci_cpu_init_idle(unsigned int cpu)
 {
 	struct device_node *cpu_node;
 	int ret;
 
+	/*
+	 * If the PSCI cpu_suspend function hook has not been initialized
+	 * idle states must not be enabled, so bail out
+	 */
+	if (!psci_ops.cpu_suspend)
+		return -EOPNOTSUPP;
+
+	if (!acpi_disabled)
+		return psci_acpi_cpu_init_idle(cpu);
+
 	cpu_node = of_get_cpu_node(cpu, NULL);
 	if (!cpu_node)
 		return -ENODEV;

include/acpi/cppc_acpi.h

@@ -15,10 +15,9 @@
 #define _CPPC_ACPI_H
 
 #include <linux/acpi.h>
-#include <linux/mailbox_controller.h>
-#include <linux/mailbox_client.h>
 #include <linux/types.h>
 
+#include <acpi/pcc.h>
 #include <acpi/processor.h>
 
 /* Only support CPPCv2 for now. */
@@ -130,8 +129,4 @@ extern int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls);
 extern int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps);
 extern int acpi_get_psd_map(struct cpudata **);
 
-/* Methods to interact with the PCC mailbox controller. */
-extern struct mbox_chan *
-	pcc_mbox_request_channel(struct mbox_client *, unsigned int);
-
 #endif /* _CPPC_ACPI_H*/

include/acpi/pcc.h

@@ -0,0 +1,29 @@
+/*
+ * PCC (Platform Communications Channel) methods
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#ifndef _PCC_H
+#define _PCC_H
+
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+
+#ifdef CONFIG_PCC
+extern struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
+						  int subspace_id);
+extern void pcc_mbox_free_channel(struct mbox_chan *chan);
+#else
+static inline struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
+							 int subspace_id)
+{
+	return NULL;
+}
+static inline void pcc_mbox_free_channel(struct mbox_chan *chan) { }
+#endif
+
+#endif /* _PCC_H */

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_lpi_state {
+	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_lpi_state 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;
@@ -242,7 +260,7 @@ extern int acpi_processor_get_performance_info(struct acpi_processor *pr);
 DECLARE_PER_CPU(struct acpi_processor *, processors);
 extern struct acpi_processor_errata errata;
 
-#ifdef ARCH_HAS_POWER_INIT
+#if defined(ARCH_HAS_POWER_INIT) && defined(CONFIG_ACPI_PROCESSOR_CSTATE)
 void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,
 					unsigned int cpu);
 int acpi_processor_ffh_cstate_probe(unsigned int cpu,
@@ -372,7 +390,7 @@ 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 +403,7 @@ 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;
 }

include/linux/acpi.h

@@ -457,8 +457,12 @@ 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_confirmed;
 
 /* PCI Host Bridge _OSC: Capabilities DWORD 2: Support Field */
 #define OSC_PCI_EXT_CONFIG_SUPPORT		0x00000001

include/linux/cpuidle.h

@@ -252,4 +252,22 @@ static inline int cpuidle_register_governor(struct cpuidle_governor *gov)
 #define CPUIDLE_DRIVER_STATE_START	0
 #endif
 
+#define CPU_PM_CPU_IDLE_ENTER(low_level_idle_enter, idx)	\
+({								\
+	int __ret;						\
+								\
+	if (!idx) {						\
+		cpu_do_idle();					\
+		return idx;					\
+	}							\
+								\
+	__ret = cpu_pm_enter();					\
+	if (!__ret) {						\
+		__ret = low_level_idle_enter(idx);		\
+		cpu_pm_exit();					\
+	}							\
+								\
+	__ret ? -1 : idx;					\
+})
+
 #endif /* _LINUX_CPUIDLE_H */