Merge branch 'pm-cpuidle'

* pm-cpuidle:
  cpuidle: ACPI: fix 'return' with no value build warning
  intel_idle: Customize IceLake server support
  cpuidle: change enter_s2idle() prototype
  cpuidle: psci: Prevent domain idlestates until consumers are ready
  cpuidle: psci: Convert PM domain to platform driver
  cpuidle: psci: Fix error path via converting to a platform driver
  cpuidle: psci: Fail cpuidle registration if set OSI mode failed
  cpuidle: psci: Split into two separate build objects
  intel_idle: Eliminate redundant static variable

8 files changed, 204 insertions, 108 deletions

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 75534c5b5433..0c65a09aec1b 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -655,8 +655,8 @@ static int acpi_idle_enter(struct cpuidle_device *dev,
 	return index;
 }
 
-static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
-				   struct cpuidle_driver *drv, int index)
+static int acpi_idle_enter_s2idle(struct cpuidle_device *dev,
+				  struct cpuidle_driver *drv, int index)
 {
 	struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 
@@ -664,16 +664,18 @@ static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 		struct acpi_processor *pr = __this_cpu_read(processors);
 
 		if (unlikely(!pr))
-			return;
+			return 0;
 
 		if (pr->flags.bm_check) {
 			acpi_idle_enter_bm(pr, cx, false);
-			return;
+			return 0;
 		} else {
 			ACPI_FLUSH_CPU_CACHE();
 		}
 	}
 	acpi_idle_do_entry(cx);
+
+	return 0;
 }
 
 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
index 51a7e89085c0..0844fadc4be8 100644
--- a/drivers/cpuidle/Kconfig.arm
+++ b/drivers/cpuidle/Kconfig.arm
@@ -23,6 +23,16 @@ config ARM_PSCI_CPUIDLE
 	  It provides an idle driver that is capable of detecting and
 	  managing idle states through the PSCI firmware interface.
 
+config ARM_PSCI_CPUIDLE_DOMAIN
+	bool "PSCI CPU idle Domain"
+	depends on ARM_PSCI_CPUIDLE
+	depends on PM_GENERIC_DOMAINS_OF
+	default y
+	help
+	  Select this to enable the PSCI based CPUidle driver to use PM domains,
+	  which is needed to support the hierarchical DT based layout of the
+	  idle states.
+
 config ARM_BIG_LITTLE_CPUIDLE
 	bool "Support for ARM big.LITTLE processors"
 	depends on ARCH_VEXPRESS_TC2_PM || ARCH_EXYNOS || COMPILE_TEST
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index f07800cbb43f..26bbc5e74123 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -21,9 +21,8 @@ obj-$(CONFIG_ARM_U8500_CPUIDLE)         += cpuidle-ux500.o
 obj-$(CONFIG_ARM_AT91_CPUIDLE)          += cpuidle-at91.o
 obj-$(CONFIG_ARM_EXYNOS_CPUIDLE)        += cpuidle-exynos.o
 obj-$(CONFIG_ARM_CPUIDLE)		+= cpuidle-arm.o
-obj-$(CONFIG_ARM_PSCI_CPUIDLE)		+= cpuidle_psci.o
-cpuidle_psci-y				:= cpuidle-psci.o
-cpuidle_psci-$(CONFIG_PM_GENERIC_DOMAINS_OF) += cpuidle-psci-domain.o
+obj-$(CONFIG_ARM_PSCI_CPUIDLE)		+= cpuidle-psci.o
+obj-$(CONFIG_ARM_PSCI_CPUIDLE_DOMAIN)	+= cpuidle-psci-domain.o
 obj-$(CONFIG_ARM_TEGRA_CPUIDLE)		+= cpuidle-tegra.o
 obj-$(CONFIG_ARM_QCOM_SPM_CPUIDLE)	+= cpuidle-qcom-spm.o
 
diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
index 423f03bbeb74..b6e9649ab0da 100644
--- a/drivers/cpuidle/cpuidle-psci-domain.c
+++ b/drivers/cpuidle/cpuidle-psci-domain.c
@@ -12,6 +12,7 @@
 #include <linux/cpu.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
+#include <linux/platform_device.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 #include <linux/psci.h>
@@ -26,7 +27,7 @@ struct psci_pd_provider {
 };
 
 static LIST_HEAD(psci_pd_providers);
-static bool osi_mode_enabled __initdata;
+static bool psci_pd_allow_domain_state;
 
 static int psci_pd_power_off(struct generic_pm_domain *pd)
 {
@@ -36,6 +37,9 @@ static int psci_pd_power_off(struct generic_pm_domain *pd)
 	if (!state->data)
 		return 0;
 
+	if (!psci_pd_allow_domain_state)
+		return -EBUSY;
+
 	/* OSI mode is enabled, set the corresponding domain state. */
 	pd_state = state->data;
 	psci_set_domain_state(*pd_state);
@@ -43,8 +47,8 @@ static int psci_pd_power_off(struct generic_pm_domain *pd)
 	return 0;
 }
 
-static int __init psci_pd_parse_state_nodes(struct genpd_power_state *states,
-					int state_count)
+static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
+				     int state_count)
 {
 	int i, ret;
 	u32 psci_state, *psci_state_buf;
@@ -73,7 +77,7 @@ free_state:
 	return ret;
 }
 
-static int __init psci_pd_parse_states(struct device_node *np,
+static int psci_pd_parse_states(struct device_node *np,
 			struct genpd_power_state **states, int *state_count)
 {
 	int ret;
@@ -101,7 +105,7 @@ static void psci_pd_free_states(struct genpd_power_state *states,
 	kfree(states);
 }
 
-static int __init psci_pd_init(struct device_node *np)
+static int psci_pd_init(struct device_node *np)
 {
 	struct generic_pm_domain *pd;
 	struct psci_pd_provider *pd_provider;
@@ -168,7 +172,7 @@ out:
 	return ret;
 }
 
-static void __init psci_pd_remove(void)
+static void psci_pd_remove(void)
 {
 	struct psci_pd_provider *pd_provider, *it;
 	struct generic_pm_domain *genpd;
@@ -186,7 +190,7 @@ static void __init psci_pd_remove(void)
 	}
 }
 
-static int __init psci_pd_init_topology(struct device_node *np, bool add)
+static int psci_pd_init_topology(struct device_node *np, bool add)
 {
 	struct device_node *node;
 	struct of_phandle_args child, parent;
@@ -212,24 +216,33 @@ static int __init psci_pd_init_topology(struct device_node *np, bool add)
 	return 0;
 }
 
-static int __init psci_pd_add_topology(struct device_node *np)
+static int psci_pd_add_topology(struct device_node *np)
 {
 	return psci_pd_init_topology(np, true);
 }
 
-static void __init psci_pd_remove_topology(struct device_node *np)
+static void psci_pd_remove_topology(struct device_node *np)
 {
 	psci_pd_init_topology(np, false);
 }
 
-static const struct of_device_id psci_of_match[] __initconst = {
+static void psci_cpuidle_domain_sync_state(struct device *dev)
+{
+	/*
+	 * All devices have now been attached/probed to the PM domain topology,
+	 * hence it's fine to allow domain states to be picked.
+	 */
+	psci_pd_allow_domain_state = true;
+}
+
+static const struct of_device_id psci_of_match[] = {
 	{ .compatible = "arm,psci-1.0" },
 	{}
 };
 
-static int __init psci_idle_init_domains(void)
+static int psci_cpuidle_domain_probe(struct platform_device *pdev)
 {
-	struct device_node *np = of_find_matching_node(NULL, psci_of_match);
+	struct device_node *np = pdev->dev.of_node;
 	struct device_node *node;
 	int ret = 0, pd_count = 0;
 
@@ -238,7 +251,7 @@ static int __init psci_idle_init_domains(void)
 
 	/* Currently limit the hierarchical topology to be used in OSI mode. */
 	if (!psci_has_osi_support())
-		goto out;
+		return 0;
 
 	/*
 	 * Parse child nodes for the "#power-domain-cells" property and
@@ -257,7 +270,7 @@ static int __init psci_idle_init_domains(void)
 
 	/* Bail out if not using the hierarchical CPU topology. */
 	if (!pd_count)
-		goto out;
+		return 0;
 
 	/* Link genpd masters/subdomains to model the CPU topology. */
 	ret = psci_pd_add_topology(np);
@@ -272,10 +285,8 @@ static int __init psci_idle_init_domains(void)
 		goto remove_pd;
 	}
 
-	osi_mode_enabled = true;
-	of_node_put(np);
 	pr_info("Initialized CPU PM domain topology\n");
-	return pd_count;
+	return 0;
 
 put_node:
 	of_node_put(node);
@@ -283,19 +294,28 @@ remove_pd:
 	if (pd_count)
 		psci_pd_remove();
 	pr_err("failed to create CPU PM domains ret=%d\n", ret);
-out:
-	of_node_put(np);
 	return ret;
 }
+
+static struct platform_driver psci_cpuidle_domain_driver = {
+	.probe  = psci_cpuidle_domain_probe,
+	.driver = {
+		.name = "psci-cpuidle-domain",
+		.of_match_table = psci_of_match,
+		.sync_state = psci_cpuidle_domain_sync_state,
+	},
+};
+
+static int __init psci_idle_init_domains(void)
+{
+	return platform_driver_register(&psci_cpuidle_domain_driver);
+}
 subsys_initcall(psci_idle_init_domains);
 
-struct device __init *psci_dt_attach_cpu(int cpu)
+struct device *psci_dt_attach_cpu(int cpu)
 {
 	struct device *dev;
 
-	if (!osi_mode_enabled)
-		return NULL;
-
 	dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
 	if (IS_ERR_OR_NULL(dev))
 		return dev;
@@ -306,3 +326,11 @@ struct device __init *psci_dt_attach_cpu(int cpu)
 
 	return dev;
 }
+
+void psci_dt_detach_cpu(struct device *dev)
+{
+	if (IS_ERR_OR_NULL(dev))
+		return;
+
+	dev_pm_domain_detach(dev, false);
+}
diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
index 3806f911b61c..74463841805f 100644
--- a/drivers/cpuidle/cpuidle-psci.c
+++ b/drivers/cpuidle/cpuidle-psci.c
@@ -17,9 +17,11 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/platform_device.h>
 #include <linux/psci.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 
 #include <asm/cpuidle.h>
 
@@ -33,7 +35,7 @@ struct psci_cpuidle_data {
 
 static DEFINE_PER_CPU_READ_MOSTLY(struct psci_cpuidle_data, psci_cpuidle_data);
 static DEFINE_PER_CPU(u32, domain_state);
-static bool psci_cpuidle_use_cpuhp __initdata;
+static bool psci_cpuidle_use_cpuhp;
 
 void psci_set_domain_state(u32 state)
 {
@@ -104,7 +106,7 @@ static int psci_idle_cpuhp_down(unsigned int cpu)
 	return 0;
 }
 
-static void __init psci_idle_init_cpuhp(void)
+static void psci_idle_init_cpuhp(void)
 {
 	int err;
 
@@ -127,30 +129,13 @@ static int psci_enter_idle_state(struct cpuidle_device *dev,
 	return psci_enter_state(idx, state[idx]);
 }
 
-static struct cpuidle_driver psci_idle_driver __initdata = {
-	.name = "psci_idle",
-	.owner = THIS_MODULE,
-	/*
-	 * PSCI idle states relies on architectural WFI to
-	 * be represented as state index 0.
-	 */
-	.states[0] = {
-		.enter                  = psci_enter_idle_state,
-		.exit_latency           = 1,
-		.target_residency       = 1,
-		.power_usage		= UINT_MAX,
-		.name                   = "WFI",
-		.desc                   = "ARM WFI",
-	}
-};
-
-static const struct of_device_id psci_idle_state_match[] __initconst = {
+static const struct of_device_id psci_idle_state_match[] = {
 	{ .compatible = "arm,idle-state",
 	  .data = psci_enter_idle_state },
 	{ },
 };
 
-int __init psci_dt_parse_state_node(struct device_node *np, u32 *state)
+int psci_dt_parse_state_node(struct device_node *np, u32 *state)
 {
 	int err = of_property_read_u32(np, "arm,psci-suspend-param", state);
 
@@ -167,9 +152,9 @@ int __init psci_dt_parse_state_node(struct device_node *np, u32 *state)
 	return 0;
 }
 
-static int __init psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
-					    struct psci_cpuidle_data *data,
-					    unsigned int state_count, int cpu)
+static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
+				     struct psci_cpuidle_data *data,
+				     unsigned int state_count, int cpu)
 {
 	/* Currently limit the hierarchical topology to be used in OSI mode. */
 	if (!psci_has_osi_support())
@@ -190,9 +175,9 @@ static int __init psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
 	return 0;
 }
 
-static int __init psci_dt_cpu_init_idle(struct cpuidle_driver *drv,
-					struct device_node *cpu_node,
-					unsigned int state_count, int cpu)
+static int psci_dt_cpu_init_idle(struct device *dev, struct cpuidle_driver *drv,
+				 struct device_node *cpu_node,
+				 unsigned int state_count, int cpu)
 {
 	int i, ret = 0;
 	u32 *psci_states;
@@ -200,7 +185,8 @@ static int __init psci_dt_cpu_init_idle(struct cpuidle_driver *drv,
 	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
 
 	state_count++; /* Add WFI state too */
-	psci_states = kcalloc(state_count, sizeof(*psci_states), GFP_KERNEL);
+	psci_states = devm_kcalloc(dev, state_count, sizeof(*psci_states),
+				   GFP_KERNEL);
 	if (!psci_states)
 		return -ENOMEM;
 
@@ -213,32 +199,26 @@ static int __init psci_dt_cpu_init_idle(struct cpuidle_driver *drv,
 		of_node_put(state_node);
 
 		if (ret)
-			goto free_mem;
+			return ret;
 
 		pr_debug("psci-power-state %#x index %d\n", psci_states[i], i);
 	}
 
-	if (i != state_count) {
-		ret = -ENODEV;
-		goto free_mem;
-	}
+	if (i != state_count)
+		return -ENODEV;
 
 	/* Initialize optional data, used for the hierarchical topology. */
 	ret = psci_dt_cpu_init_topology(drv, data, state_count, cpu);
 	if (ret < 0)
-		goto free_mem;
+		return ret;
 
 	/* Idle states parsed correctly, store them in the per-cpu struct. */
 	data->psci_states = psci_states;
 	return 0;
-
-free_mem:
-	kfree(psci_states);
-	return ret;
 }
 
-static __init int psci_cpu_init_idle(struct cpuidle_driver *drv,
-				     unsigned int cpu, unsigned int state_count)
+static int psci_cpu_init_idle(struct device *dev, struct cpuidle_driver *drv,
+			      unsigned int cpu, unsigned int state_count)
 {
 	struct device_node *cpu_node;
 	int ret;
@@ -254,14 +234,22 @@ static __init int psci_cpu_init_idle(struct cpuidle_driver *drv,
 	if (!cpu_node)
 		return -ENODEV;
 
-	ret = psci_dt_cpu_init_idle(drv, cpu_node, state_count, cpu);
+	ret = psci_dt_cpu_init_idle(dev, drv, cpu_node, state_count, cpu);
 
 	of_node_put(cpu_node);
 
 	return ret;
 }
 
-static int __init psci_idle_init_cpu(int cpu)
+static void psci_cpu_deinit_idle(int cpu)
+{
+	struct psci_cpuidle_data *data = per_cpu_ptr(&psci_cpuidle_data, cpu);
+
+	psci_dt_detach_cpu(data->dev);
+	psci_cpuidle_use_cpuhp = false;
+}
+
+static int psci_idle_init_cpu(struct device *dev, int cpu)
 {
 	struct cpuidle_driver *drv;
 	struct device_node *cpu_node;
@@ -284,17 +272,26 @@ static int __init psci_idle_init_cpu(int cpu)
 	if (ret)
 		return ret;
 
-	drv = kmemdup(&psci_idle_driver, sizeof(*drv), GFP_KERNEL);
+	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
 	if (!drv)
 		return -ENOMEM;
 
+	drv->name = "psci_idle";
+	drv->owner = THIS_MODULE;
 	drv->cpumask = (struct cpumask *)cpumask_of(cpu);
 
 	/*
-	 * Initialize idle states data, starting at index 1, since
-	 * by default idle state 0 is the quiescent state reached
-	 * by the cpu by executing the wfi instruction.
-	 *
+	 * PSCI idle states relies on architectural WFI to be represented as
+	 * state index 0.
+	 */
+	drv->states[0].enter = psci_enter_idle_state;
+	drv->states[0].exit_latency = 1;
+	drv->states[0].target_residency = 1;
+	drv->states[0].power_usage = UINT_MAX;
+	strcpy(drv->states[0].name, "WFI");
+	strcpy(drv->states[0].desc, "ARM WFI");
+
+	/*
 	 * If no DT idle states are detected (ret == 0) let the driver
 	 * initialization fail accordingly since there is no reason to
 	 * initialize the idle driver if only wfi is supported, the
@@ -302,48 +299,45 @@ static int __init psci_idle_init_cpu(int cpu)
 	 * on idle entry.
 	 */
 	ret = dt_init_idle_driver(drv, psci_idle_state_match, 1);
-	if (ret <= 0) {
-		ret = ret ? : -ENODEV;
-		goto out_kfree_drv;
-	}
+	if (ret <= 0)
+		return ret ? : -ENODEV;
 
 	/*
 	 * Initialize PSCI idle states.
 	 */
-	ret = psci_cpu_init_idle(drv, cpu, ret);
+	ret = psci_cpu_init_idle(dev, drv, cpu, ret);
 	if (ret) {
 		pr_err("CPU %d failed to PSCI idle\n", cpu);
-		goto out_kfree_drv;
+		return ret;
 	}
 
 	ret = cpuidle_register(drv, NULL);
 	if (ret)
-		goto out_kfree_drv;
+		goto deinit;
 
 	cpuidle_cooling_register(drv);
 
 	return 0;
-
-out_kfree_drv:
-	kfree(drv);
+deinit:
+	psci_cpu_deinit_idle(cpu);
 	return ret;
 }
 
 /*
- * psci_idle_init - Initializes PSCI cpuidle driver
+ * psci_idle_probe - Initializes PSCI cpuidle driver
  *
  * Initializes PSCI cpuidle driver for all CPUs, if any CPU fails
  * to register cpuidle driver then rollback to cancel all CPUs
  * registration.
  */
-static int __init psci_idle_init(void)
+static int psci_cpuidle_probe(struct platform_device *pdev)
 {
 	int cpu, ret;
 	struct cpuidle_driver *drv;
 	struct cpuidle_device *dev;
 
 	for_each_possible_cpu(cpu) {
-		ret = psci_idle_init_cpu(cpu);
+		ret = psci_idle_init_cpu(&pdev->dev, cpu);
 		if (ret)
 			goto out_fail;
 	}
@@ -356,9 +350,34 @@ out_fail:
 		dev = per_cpu(cpuidle_devices, cpu);
 		drv = cpuidle_get_cpu_driver(dev);
 		cpuidle_unregister(drv);
-		kfree(drv);
+		psci_cpu_deinit_idle(cpu);
 	}
 
 	return ret;
 }
+
+static struct platform_driver psci_cpuidle_driver = {
+	.probe = psci_cpuidle_probe,
+	.driver = {
+		.name = "psci-cpuidle",
+	},
+};
+
+static int __init psci_idle_init(void)
+{
+	struct platform_device *pdev;
+	int ret;
+
+	ret = platform_driver_register(&psci_cpuidle_driver);
+	if (ret)
+		return ret;
+
+	pdev = platform_device_register_simple("psci-cpuidle", -1, NULL, 0);
+	if (IS_ERR(pdev)) {
+		platform_driver_unregister(&psci_cpuidle_driver);
+		return PTR_ERR(pdev);
+	}
+
+	return 0;
+}
 device_initcall(psci_idle_init);
diff --git a/drivers/cpuidle/cpuidle-psci.h b/drivers/cpuidle/cpuidle-psci.h
index 7299a04dd467..d8e925e84c27 100644
--- a/drivers/cpuidle/cpuidle-psci.h
+++ b/drivers/cpuidle/cpuidle-psci.h
@@ -3,15 +3,18 @@
 #ifndef __CPUIDLE_PSCI_H
 #define __CPUIDLE_PSCI_H
 
+struct device;
 struct device_node;
 
 void psci_set_domain_state(u32 state);
-int __init psci_dt_parse_state_node(struct device_node *np, u32 *state);
+int psci_dt_parse_state_node(struct device_node *np, u32 *state);
 
-#ifdef CONFIG_PM_GENERIC_DOMAINS_OF
-struct device __init *psci_dt_attach_cpu(int cpu);
+#ifdef CONFIG_ARM_PSCI_CPUIDLE_DOMAIN
+struct device *psci_dt_attach_cpu(int cpu);
+void psci_dt_detach_cpu(struct device *dev);
 #else
-static inline struct device __init *psci_dt_attach_cpu(int cpu) { return NULL; }
+static inline struct device *psci_dt_attach_cpu(int cpu) { return NULL; }
+static inline void psci_dt_detach_cpu(struct device *dev) { }
 #endif
 
 #endif /* __CPUIDLE_PSCI_H */
diff --git a/drivers/cpuidle/cpuidle-tegra.c b/drivers/cpuidle/cpuidle-tegra.c
index 150045849d78..a12fb141875a 100644
--- a/drivers/cpuidle/cpuidle-tegra.c
+++ b/drivers/cpuidle/cpuidle-tegra.c
@@ -253,11 +253,13 @@ static int tegra_cpuidle_enter(struct cpuidle_device *dev,
 	return err ? -1 : index;
 }
 
-static void tegra114_enter_s2idle(struct cpuidle_device *dev,
-				  struct cpuidle_driver *drv,
-				  int index)
+static int tegra114_enter_s2idle(struct cpuidle_device *dev,
+				 struct cpuidle_driver *drv,
+				 int index)
 {
 	tegra_cpuidle_enter(dev, drv, index);
+
+	return 0;
 }
 
 /*
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index f4495841bf68..fd0fa9e7900b 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -66,8 +66,6 @@ static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
 static unsigned long auto_demotion_disable_flags;
 static bool disable_promotion_to_c1e;
 
-static bool lapic_timer_always_reliable;
-
 struct idle_cpu {
 	struct cpuidle_state *state_table;
 
@@ -142,7 +140,7 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev,
 	if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
 		leave_mm(cpu);
 
-	if (!static_cpu_has(X86_FEATURE_ARAT) && !lapic_timer_always_reliable) {
+	if (!static_cpu_has(X86_FEATURE_ARAT)) {
 		/*
 		 * Switch over to one-shot tick broadcast if the target C-state
 		 * is deeper than C1.
@@ -175,13 +173,15 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev,
  * Invoked as a suspend-to-idle callback routine with frozen user space, frozen
  * scheduler tick and suspended scheduler clock on the target CPU.
  */
-static __cpuidle void intel_idle_s2idle(struct cpuidle_device *dev,
-					struct cpuidle_driver *drv, int index)
+static __cpuidle int intel_idle_s2idle(struct cpuidle_device *dev,
+				       struct cpuidle_driver *drv, int index)
 {
 	unsigned long eax = flg2MWAIT(drv->states[index].flags);
 	unsigned long ecx = 1; /* break on interrupt flag */
 
 	mwait_idle_with_hints(eax, ecx);
+
+	return 0;
 }
 
 /*
@@ -752,6 +752,35 @@ static struct cpuidle_state skx_cstates[] __initdata = {
 		.enter = NULL }
 };
 
+static struct cpuidle_state icx_cstates[] __initdata = {
+	{
+		.name = "C1",
+		.desc = "MWAIT 0x00",
+		.flags = MWAIT2flg(0x00),
+		.exit_latency = 1,
+		.target_residency = 1,
+		.enter = &intel_idle,
+		.enter_s2idle = intel_idle_s2idle, },
+	{
+		.name = "C1E",
+		.desc = "MWAIT 0x01",
+		.flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
+		.exit_latency = 4,
+		.target_residency = 4,
+		.enter = &intel_idle,
+		.enter_s2idle = intel_idle_s2idle, },
+	{
+		.name = "C6",
+		.desc = "MWAIT 0x20",
+		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 128,
+		.target_residency = 384,
+		.enter = &intel_idle,
+		.enter_s2idle = intel_idle_s2idle, },
+	{
+		.enter = NULL }
+};
+
 static struct cpuidle_state atom_cstates[] __initdata = {
 	{
 		.name = "C1E",
@@ -1056,6 +1085,12 @@ static const struct idle_cpu idle_cpu_skx __initconst = {
 	.use_acpi = true,
 };
 
+static const struct idle_cpu idle_cpu_icx __initconst = {
+	.state_table = icx_cstates,
+	.disable_promotion_to_c1e = true,
+	.use_acpi = true,
+};
+
 static const struct idle_cpu idle_cpu_avn __initconst = {
 	.state_table = avn_cstates,
 	.disable_promotion_to_c1e = true,
@@ -1110,6 +1145,7 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = {
 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE_L,		&idle_cpu_skl),
 	X86_MATCH_INTEL_FAM6_MODEL(KABYLAKE,		&idle_cpu_skl),
 	X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_X,		&idle_cpu_skx),
+	X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X,		&idle_cpu_icx),
 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNL,	&idle_cpu_knl),
 	X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNM,	&idle_cpu_knl),
 	X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT,	&idle_cpu_bxt),
@@ -1562,7 +1598,7 @@ static int intel_idle_cpu_online(unsigned int cpu)
 {
 	struct cpuidle_device *dev;
 
-	if (!lapic_timer_always_reliable)
+	if (!boot_cpu_has(X86_FEATURE_ARAT))
 		tick_broadcast_enable();
 
 	/*
@@ -1655,16 +1691,13 @@ static int __init intel_idle_init(void)
 		goto init_driver_fail;
 	}
 
-	if (boot_cpu_has(X86_FEATURE_ARAT))	/* Always Reliable APIC Timer */
-		lapic_timer_always_reliable = true;
-
 	retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
 				   intel_idle_cpu_online, NULL);
 	if (retval < 0)
 		goto hp_setup_fail;
 
 	pr_debug("Local APIC timer is reliable in %s\n",
-		 lapic_timer_always_reliable ? "all C-states" : "C1");
+		 boot_cpu_has(X86_FEATURE_ARAT) ? "all C-states" : "C1");
 
 	return 0;