: ARM cpuidle changes for 4.1

index af319ac..348dc81 100644
@@ -1,6 +1,8 @@
 #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);

index 89545f6..45969f8 100644
@@ -10,7 +10,7 @@
  */
 
 #include <linux/cpuidle.h>
-#include <asm/proc-fns.h>
+#include <asm/cpuidle.h>
 
 int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
 		struct cpuidle_driver *drv, int index)

index e365c1b..306ebc5 100644
@@ -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>

index d76d086..8e21ccc 100644
@@ -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"

index 7d92e65..5742a9f 100644
@@ -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"

index 5a36722..2c9f1a8 100644
@@ -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"

index 01e398a..7622dbb 100644
@@ -17,7 +17,6 @@
 #include <linux/clockchips.h>
 
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 
 #include "common.h"
 #include "pm.h"

index 2eb0724..93aa8cb 100644
@@ -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>
 

index 4f25a7c..e22b0d9 100644
@@ -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>
 

index f8815ed..a2400ab4 100644
@@ -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>
 

index aae7bfc..f2446c7 100644
@@ -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

index 26f5f29..0c06ea2 100644
@@ -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>
 

index cea0a6c..d23d8f4 100644
@@ -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

index 66f81e4..8bf895c 100644
@@ -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);

index 002b8c9..543292b 100644
@@ -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

index 348dc81..0f84249 100644
@@ -27,4 +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

83 lines not on this page · raw message

index c60643f..460a38b 100644
@@ -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

index ac78910..91c0930 100644
@@ -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()

index 39a2c62..0cea244 100644
@@ -49,7 +49,7 @@ 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();
 	}

index 460a38b..141b2fc 100644
@@ -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;
 }

index 5c08966..a78143a 100644
@@ -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);

index 0cea244..6ef291c7 100644
@@ -110,7 +110,7 @@ static int __init arm64_idle_init(void)
 	 * idle states suspend back-end specific data
 	 */
 	for_each_possible_cpu(cpu) {
-		ret = cpu_init_idle(cpu);
+		ret = arm_cpuidle_init(cpu);
 		if (ret) {
 			pr_err("CPU %d failed to init idle CPU ops\n", cpu);
 			return ret;

index 6ef291c7..1c94b88 100644
@@ -1,5 +1,5 @@
 /*
- * ARM64 generic CPU idle driver.
+ * ARM/ARM64 generic CPU idle driver.
  *
  * Copyright (C) 2014 ARM Ltd.
  * Author: Lorenzo Pieralisi <[email protected]>

@@ -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>

@@ -23,7 +23,7 @@
 #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 +32,8 @@
  * 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;
 

@@ -57,8 +57,8 @@ 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 +68,32 @@ 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;
 
 	/*
 	 * Initialize idle states data, starting at index 1.

@@ -101,7 +101,7 @@ 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;
 

@@ -119,4 +119,4 @@ static int __init arm64_idle_init(void)
 
 	return cpuidle_register(drv, NULL);
 }
-device_initcall(arm64_idle_init);
+device_initcall(arm_idle_init);

122 lines not on this page · raw message

122 lines not on this page · raw message

index 1c94b88..545069d 100644
@@ -17,6 +17,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/slab.h>
 
 #include <asm/cpuidle.h>
 

@@ -94,6 +95,7 @@ static int __init arm_idle_init(void)
 {
 	int cpu, ret;
 	struct cpuidle_driver *drv = &arm_idle_driver;
+	struct cpuidle_device *dev;
 
 	/*
 	 * Initialize idle states data, starting at index 1.

@@ -105,18 +107,57 @@ static int __init arm_idle_init(void)
 	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 = 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(arm_idle_init);

index 2b0dae3..318da33 100644
@@ -21,6 +21,17 @@ static const struct of_cpuidle_method __cpuidle_method_of_table_sentinel
 
 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)
 {

@@ -29,6 +40,16 @@ 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;

@@ -40,6 +61,15 @@ int arm_cpuidle_suspend(int 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;

@@ -51,6 +81,19 @@ static struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
 	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;

@@ -75,6 +118,22 @@ static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
 	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);