Merge back earlier cpuidle material for v4.1.

arch/arm/include/asm/cpuidle.h

 #ifndef __ASM_ARM_CPUIDLE_H
 #define __ASM_ARM_CPUIDLE_H
 
+#include <asm/proc-fns.h>
+
 #ifdef CONFIG_CPU_IDLE
 extern int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
 		struct cpuidle_driver *drv, int index);
@@ -25,4 +27,25 @@ static inline int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
  */
 #define ARM_CPUIDLE_WFI_STATE ARM_CPUIDLE_WFI_STATE_PWR(UINT_MAX)
 
+struct device_node;
+
+struct cpuidle_ops {
+	int (*suspend)(int cpu, unsigned long arg);
+	int (*init)(struct device_node *, int cpu);
+};
+
+struct of_cpuidle_method {
+	const char *method;
+	struct cpuidle_ops *ops;
+};
+
+#define CPUIDLE_METHOD_OF_DECLARE(name, _method, _ops)			\
+	static const struct of_cpuidle_method __cpuidle_method_of_table_##name \
+	__used __section(__cpuidle_method_of_table)			\
+	= { .method = _method, .ops = _ops }
+
+extern int arm_cpuidle_suspend(int index);
+
+extern int arm_cpuidle_init(int cpu);
+
 #endif

arch/arm/kernel/cpuidle.c

@@ -10,8 +10,28 @@
  */
 
 #include <linux/cpuidle.h>
-#include <asm/proc-fns.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <asm/cpuidle.h>
 
+extern struct of_cpuidle_method __cpuidle_method_of_table[];
+
+static const struct of_cpuidle_method __cpuidle_method_of_table_sentinel
+	__used __section(__cpuidle_method_of_table_end);
+
+static struct cpuidle_ops cpuidle_ops[NR_CPUS];
+
+/**
+ * arm_cpuidle_simple_enter() - a wrapper to cpu_do_idle()
+ * @dev: not used
+ * @drv: not used
+ * @index: not used
+ *
+ * A trivial wrapper to allow the cpu_do_idle function to be assigned as a
+ * cpuidle callback by matching the function signature.
+ *
+ * Returns the index passed as parameter
+ */
 int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
 		struct cpuidle_driver *drv, int index)
 {
@@ -19,3 +39,114 @@ int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
 
 	return index;
 }
+
+/**
+ * arm_cpuidle_suspend() - function to enter low power idle states
+ * @index: an integer used as an identifier for the low level PM callbacks
+ *
+ * This function calls the underlying arch specific low level PM code as
+ * registered at the init time.
+ *
+ * Returns -EOPNOTSUPP if no suspend callback is defined, the result of the
+ * callback otherwise.
+ */
+int arm_cpuidle_suspend(int index)
+{
+	int ret = -EOPNOTSUPP;
+	int cpu = smp_processor_id();
+
+	if (cpuidle_ops[cpu].suspend)
+		ret = cpuidle_ops[cpu].suspend(cpu, index);
+
+	return ret;
+}
+
+/**
+ * arm_cpuidle_get_ops() - find a registered cpuidle_ops by name
+ * @method: the method name
+ *
+ * Search in the __cpuidle_method_of_table array the cpuidle ops matching the
+ * method name.
+ *
+ * Returns a struct cpuidle_ops pointer, NULL if not found.
+ */
+static struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
+{
+	struct of_cpuidle_method *m = __cpuidle_method_of_table;
+
+	for (; m->method; m++)
+		if (!strcmp(m->method, method))
+			return m->ops;
+
+	return NULL;
+}
+
+/**
+ * arm_cpuidle_read_ops() - Initialize the cpuidle ops with the device tree
+ * @dn: a pointer to a struct device node corresponding to a cpu node
+ * @cpu: the cpu identifier
+ *
+ * Get the method name defined in the 'enable-method' property, retrieve the
+ * associated cpuidle_ops and do a struct copy. This copy is needed because all
+ * cpuidle_ops are tagged __initdata and will be unloaded after the init
+ * process.
+ *
+ * Return 0 on sucess, -ENOENT if no 'enable-method' is defined, -EOPNOTSUPP if
+ * no cpuidle_ops is registered for the 'enable-method'.
+ */
+static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
+{
+	const char *enable_method;
+	struct cpuidle_ops *ops;
+
+	enable_method = of_get_property(dn, "enable-method", NULL);
+	if (!enable_method)
+		return -ENOENT;
+
+	ops = arm_cpuidle_get_ops(enable_method);
+	if (!ops) {
+		pr_warn("%s: unsupported enable-method property: %s\n",
+			dn->full_name, enable_method);
+		return -EOPNOTSUPP;
+	}
+
+	cpuidle_ops[cpu] = *ops; /* structure copy */
+
+	pr_notice("cpuidle: enable-method property '%s'"
+		  " found operations\n", enable_method);
+
+	return 0;
+}
+
+/**
+ * arm_cpuidle_init() - Initialize cpuidle_ops for a specific cpu
+ * @cpu: the cpu to be initialized
+ *
+ * Initialize the cpuidle ops with the device for the cpu and then call
+ * the cpu's idle initialization callback. This may fail if the underlying HW
+ * is not operational.
+ *
+ * Returns:
+ *  0 on success,
+ *  -ENODEV if it fails to find the cpu node in the device tree,
+ *  -EOPNOTSUPP if it does not find a registered cpuidle_ops for this cpu,
+ *  -ENOENT if it fails to find an 'enable-method' property,
+ *  -ENXIO if the HW reports a failure or a misconfiguration,
+ *  -ENOMEM if the HW report an memory allocation failure 
+ */
+int __init arm_cpuidle_init(int cpu)
+{
+	struct device_node *cpu_node = of_cpu_device_node_get(cpu);
+	int ret;
+
+	if (!cpu_node)
+		return -ENODEV;
+
+	ret = arm_cpuidle_read_ops(cpu_node, cpu);
+	if (!ret && cpuidle_ops[cpu].init)
+		ret = cpuidle_ops[cpu].init(cpu_node, cpu);
+
+	of_node_put(cpu_node);
+
+	return ret;
+}

arch/arm/mach-davinci/cpuidle.c

@@ -17,7 +17,6 @@
 #include <linux/cpuidle.h>
 #include <linux/io.h>
 #include <linux/export.h>
-#include <asm/proc-fns.h>
 #include <asm/cpuidle.h>
 
 #include <mach/cpuidle.h>

arch/arm/mach-imx/cpuidle-imx6q.c

@@ -9,7 +9,6 @@
 #include <linux/cpuidle.h>
 #include <linux/module.h>
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 
 #include "common.h"
 #include "cpuidle.h"

arch/arm/mach-imx/cpuidle-imx6sl.c

@@ -9,7 +9,6 @@
 #include <linux/cpuidle.h>
 #include <linux/module.h>
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 
 #include "common.h"
 #include "cpuidle.h"

arch/arm/mach-imx/cpuidle-imx6sx.c

@@ -10,7 +10,6 @@
 #include <linux/cpu_pm.h>
 #include <linux/module.h>
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 #include <asm/suspend.h>
 
 #include "common.h"

arch/arm/mach-omap2/cpuidle44xx.c

@@ -17,7 +17,6 @@
 #include <linux/clockchips.h>
 
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 
 #include "common.h"
 #include "pm.h"

arch/arm/mach-s3c64xx/cpuidle.c

@@ -16,7 +16,7 @@
 #include <linux/export.h>
 #include <linux/time.h>
 
-#include <asm/proc-fns.h>
+#include <asm/cpuidle.h>
 
 #include <mach/map.h>
 

arch/arm/mach-tegra/cpuidle-tegra20.c

@@ -27,7 +27,6 @@
 #include <linux/module.h>
 
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
 

arch/arm/mach-tegra/cpuidle-tegra30.c

@@ -27,7 +27,6 @@
 #include <linux/module.h>
 
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
 

arch/arm64/configs/defconfig

@@ -48,7 +48,7 @@ CONFIG_CMDLINE="console=ttyAMA0"
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
 CONFIG_COMPAT=y
 CONFIG_CPU_IDLE=y
-CONFIG_ARM64_CPUIDLE=y
+CONFIG_ARM_CPUIDLE=y
 CONFIG_NET=y
 CONFIG_PACKET=y
 CONFIG_UNIX=y

arch/arm64/include/asm/cpuidle.h

@@ -4,10 +4,10 @@
 #include <asm/proc-fns.h>
 
 #ifdef CONFIG_CPU_IDLE
-extern int cpu_init_idle(unsigned int cpu);
+extern int arm_cpuidle_init(unsigned int cpu);
 extern int cpu_suspend(unsigned long arg);
 #else
-static inline int cpu_init_idle(unsigned int cpu)
+static inline int arm_cpuidle_init(unsigned int cpu)
 {
 	return -EOPNOTSUPP;
 }
@@ -17,5 +17,8 @@ static inline int cpu_suspend(unsigned long arg)
 	return -EOPNOTSUPP;
 }
 #endif
-
+static inline int arm_cpuidle_suspend(int index)
+{
+	return cpu_suspend(index);
+}
 #endif

arch/arm64/kernel/cpuidle.c

@@ -15,7 +15,7 @@
 #include <asm/cpuidle.h>
 #include <asm/cpu_ops.h>
 
-int cpu_init_idle(unsigned int cpu)
+int arm_cpuidle_init(unsigned int cpu)
 {
 	int ret = -EOPNOTSUPP;
 	struct device_node *cpu_node = of_cpu_device_node_get(cpu);

drivers/cpuidle/Kconfig

@@ -29,15 +29,10 @@ config DT_IDLE_STATES
 	bool
 
 menu "ARM CPU Idle Drivers"
-depends on ARM
+depends on ARM || ARM64
 source "drivers/cpuidle/Kconfig.arm"
 endmenu
 
-menu "ARM64 CPU Idle Drivers"
-depends on ARM64
-source "drivers/cpuidle/Kconfig.arm64"
-endmenu
-
 menu "MIPS CPU Idle Drivers"
 depends on MIPS
 source "drivers/cpuidle/Kconfig.mips"

drivers/cpuidle/Kconfig.arm

 #
 # ARM CPU Idle drivers
 #
+config ARM_CPUIDLE
+        bool "Generic ARM/ARM64 CPU idle Driver"
+        select DT_IDLE_STATES
+        help
+          Select this to enable generic cpuidle driver for ARM.
+          It provides a generic idle driver whose idle states are configured
+          at run-time through DT nodes. The CPUidle suspend backend is
+          initialized by calling the CPU operations init idle hook
+          provided by architecture code.
+
 config ARM_BIG_LITTLE_CPUIDLE
 	bool "Support for ARM big.LITTLE processors"
 	depends on ARCH_VEXPRESS_TC2_PM || ARCH_EXYNOS
-	depends on MCPM
+	depends on MCPM && !ARM64
 	select ARM_CPU_SUSPEND
 	select CPU_IDLE_MULTIPLE_DRIVERS
 	select DT_IDLE_STATES
@@ -16,51 +26,51 @@ config ARM_BIG_LITTLE_CPUIDLE
 
 config ARM_CLPS711X_CPUIDLE
 	bool "CPU Idle Driver for CLPS711X processors"
-	depends on ARCH_CLPS711X || COMPILE_TEST
+	depends on ARCH_CLPS711X && !ARM64 || COMPILE_TEST
 	help
 	  Select this to enable cpuidle on Cirrus Logic CLPS711X SOCs.
 
 config ARM_HIGHBANK_CPUIDLE
 	bool "CPU Idle Driver for Calxeda processors"
-	depends on ARM_PSCI
+	depends on ARM_PSCI && !ARM64
 	select ARM_CPU_SUSPEND
 	help
 	  Select this to enable cpuidle on Calxeda processors.
 
 config ARM_KIRKWOOD_CPUIDLE
 	bool "CPU Idle Driver for Marvell Kirkwood SoCs"
-	depends on MACH_KIRKWOOD
+	depends on MACH_KIRKWOOD && !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
+	depends on ARCH_ZYNQ && !ARM64
 	help
 	  Select this to enable cpuidle on Xilinx Zynq processors.
 
 config ARM_U8500_CPUIDLE
 	bool "Cpu Idle Driver for the ST-E u8500 processors"
-	depends on ARCH_U8500
+	depends on ARCH_U8500 && !ARM64
 	help
 	  Select this to enable cpuidle for ST-E u8500 processors
 
 config ARM_AT91_CPUIDLE
 	bool "Cpu Idle Driver for the AT91 processors"
 	default y
-	depends on ARCH_AT91
+	depends on ARCH_AT91 && !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
+	depends on ARCH_EXYNOS && !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
+	depends on ARCH_MVEBU && !ARM64
 	help
 	  Select this to enable cpuidle on Armada 370, 38x and XP processors.

drivers/cpuidle/Kconfig.arm64

-#
-# ARM64 CPU Idle drivers
-#
-
-config ARM64_CPUIDLE
-	bool "Generic ARM64 CPU idle Driver"
-	select DT_IDLE_STATES
-	help
-	  Select this to enable generic cpuidle driver for ARM64.
-	  It provides a generic idle driver whose idle states are configured
-	  at run-time through DT nodes. The CPUidle suspend backend is
-	  initialized by calling the CPU operations init idle hook
-	  provided by architecture code.

drivers/cpuidle/Makefile

@@ -17,15 +17,12 @@ obj-$(CONFIG_ARM_ZYNQ_CPUIDLE)		+= cpuidle-zynq.o
 obj-$(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
 
 ###############################################################################
 # MIPS drivers
 obj-$(CONFIG_MIPS_CPS_CPUIDLE)		+= cpuidle-cps.o
 
-###############################################################################
-# ARM64 drivers
-obj-$(CONFIG_ARM64_CPUIDLE)		+= cpuidle-arm64.o
-
 ###############################################################################
 # POWERPC drivers
 obj-$(CONFIG_PSERIES_CPUIDLE)		+= cpuidle-pseries.o

drivers/cpuidle/cpuidle-arm64.c → drivers/cpuidle/cpuidle-arm.c

 /*
- * ARM64 generic CPU idle driver.
+ * ARM/ARM64 generic CPU idle driver.
  *
  * Copyright (C) 2014 ARM Ltd.
  * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
@@ -9,7 +9,7 @@
  * published by the Free Software Foundation.
  */
 
-#define pr_fmt(fmt) "CPUidle arm64: " fmt
+#define pr_fmt(fmt) "CPUidle arm: " fmt
 
 #include <linux/cpuidle.h>
 #include <linux/cpumask.h>
@@ -17,13 +17,14 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/slab.h>
 
 #include <asm/cpuidle.h>
 
 #include "dt_idle_states.h"
 
 /*
- * arm64_enter_idle_state - Programs CPU to enter the specified state
+ * arm_enter_idle_state - Programs CPU to enter the specified state
  *
  * dev: cpuidle device
  * drv: cpuidle driver
@@ -32,8 +33,8 @@
  * Called from the CPUidle framework to program the device to the
  * specified target state selected by the governor.
  */
-static int arm64_enter_idle_state(struct cpuidle_device *dev,
-				  struct cpuidle_driver *drv, int idx)
+static int arm_enter_idle_state(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv, int idx)
 {
 	int ret;
 
@@ -49,7 +50,7 @@ static int arm64_enter_idle_state(struct cpuidle_device *dev,
 		 * call the CPU ops suspend protocol with idle index as a
 		 * parameter.
 		 */
-		ret = cpu_suspend(idx);
+		arm_cpuidle_suspend(idx);
 
 		cpu_pm_exit();
 	}
@@ -57,8 +58,8 @@ static int arm64_enter_idle_state(struct cpuidle_device *dev,
 	return ret ? -1 : idx;
 }
 
-static struct cpuidle_driver arm64_idle_driver = {
-	.name = "arm64_idle",
+static struct cpuidle_driver arm_idle_driver = {
+	.name = "arm_idle",
 	.owner = THIS_MODULE,
 	/*
 	 * State at index 0 is standby wfi and considered standard
@@ -68,32 +69,33 @@ static struct cpuidle_driver arm64_idle_driver = {
 	 * handler for idle state index 0.
 	 */
 	.states[0] = {
-		.enter                  = arm64_enter_idle_state,
+		.enter                  = arm_enter_idle_state,
 		.exit_latency           = 1,
 		.target_residency       = 1,
 		.power_usage		= UINT_MAX,
 		.name                   = "WFI",
-		.desc                   = "ARM64 WFI",
+		.desc                   = "ARM WFI",
 	}
 };
 
-static const struct of_device_id arm64_idle_state_match[] __initconst = {
+static const struct of_device_id arm_idle_state_match[] __initconst = {
 	{ .compatible = "arm,idle-state",
-	  .data = arm64_enter_idle_state },
+	  .data = arm_enter_idle_state },
 	{ },
 };
 
 /*
- * arm64_idle_init
+ * arm_idle_init
  *
- * Registers the arm64 specific cpuidle driver with the cpuidle
+ * Registers the arm specific cpuidle driver with the cpuidle
  * framework. It relies on core code to parse the idle states
  * and initialize them using driver data structures accordingly.
  */
-static int __init arm64_idle_init(void)
+static int __init arm_idle_init(void)
 {
 	int cpu, ret;
-	struct cpuidle_driver *drv = &arm64_idle_driver;
+	struct cpuidle_driver *drv = &arm_idle_driver;
+	struct cpuidle_device *dev;
 
 	/*
 	 * Initialize idle states data, starting at index 1.
@@ -101,22 +103,61 @@ static int __init arm64_idle_init(void)
 	 * let the driver initialization fail accordingly since there is no
 	 * reason to initialize the idle driver if only wfi is supported.
 	 */
-	ret = dt_init_idle_driver(drv, arm64_idle_state_match, 1);
+	ret = dt_init_idle_driver(drv, arm_idle_state_match, 1);
 	if (ret <= 0)
 		return ret ? : -ENODEV;
 
+	ret = cpuidle_register_driver(drv);
+	if (ret) {
+		pr_err("Failed to register cpuidle driver\n");
+		return ret;
+	}
+
 	/*
 	 * Call arch CPU operations in order to initialize
 	 * idle states suspend back-end specific data
 	 */
 	for_each_possible_cpu(cpu) {
-		ret = cpu_init_idle(cpu);
+		ret = arm_cpuidle_init(cpu);
+
+		/*
+		 * Skip the cpuidle device initialization if the reported
+		 * failure is a HW misconfiguration/breakage (-ENXIO).
+		 */
+		if (ret == -ENXIO)
+			continue;
+
 		if (ret) {
 			pr_err("CPU %d failed to init idle CPU ops\n", cpu);
-			return ret;
+			goto out_fail;
+		}
+
+		dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+		if (!dev) {
+			pr_err("Failed to allocate cpuidle device\n");
+			goto out_fail;
+		}
+		dev->cpu = cpu;
+
+		ret = cpuidle_register_device(dev);
+		if (ret) {
+			pr_err("Failed to register cpuidle device for CPU %d\n",
+			       cpu);
+			kfree(dev);
+			goto out_fail;
 		}
 	}
 
-	return cpuidle_register(drv, NULL);
+	return 0;
+out_fail:
+	while (--cpu >= 0) {
+		dev = per_cpu(cpuidle_devices, cpu);
+		cpuidle_unregister_device(dev);
+		kfree(dev);
+	}
+
+	cpuidle_unregister_driver(drv);
+
+	return ret;
 }
-device_initcall(arm64_idle_init);
+device_initcall(arm_idle_init);

drivers/cpuidle/cpuidle-at91.c

@@ -19,7 +19,6 @@
 #include <linux/cpuidle.h>
 #include <linux/io.h>
 #include <linux/export.h>
-#include <asm/proc-fns.h>
 #include <asm/cpuidle.h>
 
 #define AT91_MAX_STATES	2

drivers/cpuidle/cpuidle-exynos.c

@@ -19,7 +19,6 @@
 #include <linux/of.h>
 #include <linux/platform_data/cpuidle-exynos.h>
 
-#include <asm/proc-fns.h>
 #include <asm/suspend.h>
 #include <asm/cpuidle.h>
 

drivers/cpuidle/cpuidle-kirkwood.c

@@ -21,7 +21,6 @@
 #include <linux/cpuidle.h>
 #include <linux/io.h>
 #include <linux/export.h>
-#include <asm/proc-fns.h>
 #include <asm/cpuidle.h>
 
 #define KIRKWOOD_MAX_STATES	2

drivers/cpuidle/cpuidle-ux500.c

@@ -19,7 +19,6 @@
 #include <linux/platform_device.h>
 
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 
 static atomic_t master = ATOMIC_INIT(0);
 static DEFINE_SPINLOCK(master_lock);

drivers/cpuidle/cpuidle-zynq.c

@@ -28,7 +28,6 @@
 #include <linux/init.h>
 #include <linux/cpuidle.h>
 #include <linux/platform_device.h>
-#include <asm/proc-fns.h>
 #include <asm/cpuidle.h>
 
 #define ZYNQ_MAX_STATES		2

include/asm-generic/vmlinux.lds.h

@@ -167,6 +167,7 @@
 #define IOMMU_OF_TABLES()	OF_TABLE(CONFIG_OF_IOMMU, iommu)
 #define RESERVEDMEM_OF_TABLES()	OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem)
 #define CPU_METHOD_OF_TABLES()	OF_TABLE(CONFIG_SMP, cpu_method)
+#define CPUIDLE_METHOD_OF_TABLES() OF_TABLE(CONFIG_CPU_IDLE, cpuidle_method)
 #define EARLYCON_OF_TABLES()	OF_TABLE(CONFIG_SERIAL_EARLYCON, earlycon)
 
 #define KERNEL_DTB()							\
@@ -501,6 +502,7 @@
 	CLKSRC_OF_TABLES()						\
 	IOMMU_OF_TABLES()						\
 	CPU_METHOD_OF_TABLES()						\
+	CPUIDLE_METHOD_OF_TABLES()					\
 	KERNEL_DTB()							\
 	IRQCHIP_OF_MATCH_TABLE()					\
 	EARLYCON_OF_TABLES()