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ARM: cpuidle: Unify the ARM64/ARM DT approach

PATCH In review Daniel Lezcano 3 participants 31 messages Mar 20, 2015 – Mar 25, 2015

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#0 lore raw

v3 cover ARM: cpuidle: Unify the ARM64/ARM DT approach

There is a big number of cpuidle drivers for the ARM architecture.

These drivers have been cleaned up and grouped into the drivers/cpuidle directory to keep track of the changes more easily and ensure the code is following the same scheme across the drivers.

That had the benefit of simplifying the code and factor out a lot of common parts. Beside that, as the drivers belong to the 'drivers' directory, we had to split the arch specific bits and the generic code in order to keep everything self contained. The platform driver paradigm was used for this purpose.

Unfortunately, this approach is now no longer accepted and a different solution must be provided to reach the same goal: one example is the Qualcomm cpuidle driver upstreaming attempt.

In the meantime, ARM64 developed a generic cpuidle driver based on DT definition.

The DT definition provides an 'enable-method' to specify one of the cpu operations (PSCI, ...).

This patchset unify this driver with ARM32, using the same DT definition.

Thanks with this patchset we can use the 'enable-method' to specify a cpu operations, hence get rid of the platform driver approach and go further in the cpuidle driver flexibility via the DT.

Changelog:

V3:
* Fixed unroll loop when failing to register the device
* Removed the per cpu cpuidle_device
* Remove goto statement in the registration path
* Fixed a compilation failure with allyesconfig on arm64

V2:
* Used smp_operations style for cpuidle_ops
* Fixed some nits in the comments
* Added a patch to change the name of the functions
* Added per cpu device registration patch

Daniel Lezcano (8):
ARM: cpuidle: Remove duplicate header inclusion
ARM: cpuidle: Add a cpuidle ops structure to be used for DT
ARM64: cpuidle: Replace cpu_suspend by the common ARM/ARM64 function
ARM64: cpuidle: Rename cpu_init_idle to a common function name
ARM64: cpuidle: Remove arm64 reference
ARM: cpuidle: Enable the ARM64 driver for both ARM32/ARM64
ARM: cpuidle: Register per cpuidle device
ARM: cpuidle: Change function name to be consistent with x86

 arch/arm/include/asm/cpuidle.h                     | 23 +++++++
 arch/arm/kernel/cpuidle.c                          | 74 +++++++++++++++++++-
 arch/arm/mach-davinci/cpuidle.c                    |  1 -
 arch/arm/mach-imx/cpuidle-imx6q.c                  |  1 -
 arch/arm/mach-imx/cpuidle-imx6sl.c                 |  1 -
 arch/arm/mach-imx/cpuidle-imx6sx.c                 |  1 -
 arch/arm/mach-omap2/cpuidle44xx.c                  |  1 -
 arch/arm/mach-s3c64xx/cpuidle.c                    |  2 +-
 arch/arm/mach-tegra/cpuidle-tegra20.c              |  1 -
 arch/arm/mach-tegra/cpuidle-tegra30.c              |  1 -
 arch/arm64/include/asm/cpuidle.h                   |  9 ++-
 arch/arm64/kernel/cpuidle.c                        |  2 +-
 drivers/cpuidle/Kconfig                            |  7 +-
 drivers/cpuidle/Kconfig.arm                        | 12 +++-
 drivers/cpuidle/Kconfig.arm64                      | 13 ----
 drivers/cpuidle/Makefile                           |  5 +-
 drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} | 80 ++++++++++++++++------
 drivers/cpuidle/cpuidle-at91.c                     |  1 -
 drivers/cpuidle/cpuidle-exynos.c                   |  1 -
 drivers/cpuidle/cpuidle-kirkwood.c                 |  1 -
 drivers/cpuidle/cpuidle-ux500.c                    |  1 -
 drivers/cpuidle/cpuidle-zynq.c                     |  1 -
 include/asm-generic/vmlinux.lds.h                  |  2 +
 23 files changed, 178 insertions(+), 63 deletions(-)
 delete mode 100644 drivers/cpuidle/Kconfig.arm64
 rename drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} (57%)
Signature · 1 line
1.9.1
#1 lore raw

PATCH v3 1/8 ARM: cpuidle: Remove duplicate header inclusion

The cpu_do_idle() function is always used by the cpuidle drivers.

That led to have each driver including cpuidle.h and proc-fns.h, they are always paired. That makes a lot of duplicate headers inclusion. Instead of including both in each .c file, move the proc-fns.h header inclusion in the cpuidle.h header file directly, so we can save some line of code.

---
 arch/arm/include/asm/cpuidle.h        | 2 ++
 arch/arm/kernel/cpuidle.c             | 2 +-
 arch/arm/mach-davinci/cpuidle.c       | 1 -
 arch/arm/mach-imx/cpuidle-imx6q.c     | 1 -
 arch/arm/mach-imx/cpuidle-imx6sl.c    | 1 -
 arch/arm/mach-imx/cpuidle-imx6sx.c    | 1 -
 arch/arm/mach-omap2/cpuidle44xx.c     | 1 -
 arch/arm/mach-s3c64xx/cpuidle.c       | 2 +-
 arch/arm/mach-tegra/cpuidle-tegra20.c | 1 -
 arch/arm/mach-tegra/cpuidle-tegra30.c | 1 -
 drivers/cpuidle/cpuidle-at91.c        | 1 -
 drivers/cpuidle/cpuidle-exynos.c      | 1 -
 drivers/cpuidle/cpuidle-kirkwood.c    | 1 -
 drivers/cpuidle/cpuidle-ux500.c       | 1 -
 drivers/cpuidle/cpuidle-zynq.c        | 1 -
 15 files changed, 4 insertions(+), 14 deletions(-)
arch/arm/include/asm/cpuidle.h +2 -0
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);
arch/arm/kernel/cpuidle.c +1 -1
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)
arch/arm/mach-davinci/cpuidle.c +0 -1
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>
arch/arm/mach-imx/cpuidle-imx6q.c +0 -1
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"
arch/arm/mach-imx/cpuidle-imx6sl.c +0 -1
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"
arch/arm/mach-imx/cpuidle-imx6sx.c +0 -1
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"
arch/arm/mach-omap2/cpuidle44xx.c +0 -1
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"
arch/arm/mach-s3c64xx/cpuidle.c +1 -1
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>
 
arch/arm/mach-tegra/cpuidle-tegra20.c +0 -1
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>
 
arch/arm/mach-tegra/cpuidle-tegra30.c +0 -1
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>
 
drivers/cpuidle/cpuidle-at91.c +0 -1
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
drivers/cpuidle/cpuidle-exynos.c +0 -1
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>
 
drivers/cpuidle/cpuidle-kirkwood.c +0 -1
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
drivers/cpuidle/cpuidle-ux500.c +0 -1
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);
drivers/cpuidle/cpuidle-zynq.c +0 -1
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
Signature · 1 line
1.9.1
#2 lore raw

PATCH v3 2/8 ARM: cpuidle: Add a cpuidle ops structure to be used for DT

In reply to Daniel Lezcano

The current state of the different cpuidle drivers is the different PM operations are passed via the platform_data using the platform driver paradigm.

This approach allowed to split the low level PM code from the arch specific and the generic cpuidle code.

Unfortunately there are complaints about this approach as, in the context of the single kernel image, we have multiple drivers loaded in memory for nothing and the platform driver is not adequate for cpuidle.

This patch provides a common interface via cpuidle ops for all new cpuidle driver and a definition for the device tree.

It will allow with the next patches to a have a common definition with ARM64 and share the same cpuidle driver.

The code is optimized to use the __init section intensively in order to reduce the memory footprint after the driver is initialized and unify the function names with ARM64.

---
 arch/arm/include/asm/cpuidle.h    | 21 ++++++++++++
 arch/arm/kernel/cpuidle.c         | 72 +++++++++++++++++++++++++++++++++++++++
 arch/arm64/include/asm/cpuidle.h  |  5 ++-
 include/asm-generic/vmlinux.lds.h |  2 ++
 4 files changed, 99 insertions(+), 1 deletion(-)
arch/arm/include/asm/cpuidle.h +21 -0
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
arch/arm/kernel/cpuidle.c +72 -0

83 lines not on this page · raw message

arch/arm64/include/asm/cpuidle.h +4 -1
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
include/asm-generic/vmlinux.lds.h +2 -0
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()
Signature · 1 line
1.9.1
Acked-by on v3 2/8
#3 lore raw

Re: [PATCH V3 2/8] ARM: cpuidle: Add a cpuidle ops structure to be used for DT

Quoted 17 lines · Daniel Lezcano

The current state of the different cpuidle drivers is the different PM operations are passed via the platform_data using the platform driver paradigm.

This approach allowed to split the low level PM code from the arch specific and the generic cpuidle code.

Unfortunately there are complaints about this approach as, in the context of the single kernel image, we have multiple drivers loaded in memory for nothing and the platform driver is not adequate for cpuidle.

This patch provides a common interface via cpuidle ops for all new cpuidle driver and a definition for the device tree.

It will allow with the next patches to a have a common definition with ARM64 and share the same cpuidle driver.

Quoted 7 lines

The code is optimized to use the __init section intensively in order to reduce the memory footprint after the driver is initialized and unify the function names with ARM64.

Thanks for moving to OF tables. We can merge smp ops and cpuidle ops later on.

Signature · 2 lines
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
#4 lore raw

PATCH v3 3/8 ARM64: cpuidle: Replace cpu_suspend by the common ARM/ARM64 function

In reply to Daniel Lezcano

Call the common ARM/ARM64 'arm_cpuidle_suspend' instead of cpu_suspend function which is specific to ARM64.

---
 drivers/cpuidle/cpuidle-arm64.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/cpuidle/cpuidle-arm64.c +1 -1
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();
 	}
Signature · 1 line
1.9.1
#5 lore raw

PATCH v3 4/8 ARM64: cpuidle: Rename cpu_init_idle to a common function name

In reply to Daniel Lezcano

With this change the cpuidle-arm64.c file calls the same function name for both ARM and ARM64.

---
 arch/arm64/include/asm/cpuidle.h | 4 ++--
 arch/arm64/kernel/cpuidle.c      | 2 +-
 drivers/cpuidle/cpuidle-arm64.c  | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)
arch/arm64/include/asm/cpuidle.h +2 -2
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;
 }
arch/arm64/kernel/cpuidle.c +1 -1
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);
drivers/cpuidle/cpuidle-arm64.c +1 -1
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;
Signature · 1 line
1.9.1
Acked-by on v3 4/8
#6 lore raw

Re: [PATCH V3 4/8] ARM64: cpuidle: Rename cpu_init_idle to a common function name

Quoted 6 lines · Daniel Lezcano

With this change the cpuidle-arm64.c file calls the same function name for both ARM and ARM64.

Quoted 53 lines
---
 arch/arm64/include/asm/cpuidle.h | 4 ++--
 arch/arm64/kernel/cpuidle.c      | 2 +-
 drivers/cpuidle/cpuidle-arm64.c  | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)
arch/arm64/include/asm/cpuidle.h +2 -2
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;
 }
arch/arm64/kernel/cpuidle.c +1 -1
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);
drivers/cpuidle/cpuidle-arm64.c +1 -1
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;
Signature · 1 line
1.9.1
#7 lore raw

PATCH v3 5/8 ARM64: cpuidle: Remove arm64 reference

In reply to Daniel Lezcano

In the next patch, this driver will be common across ARM/ARM64. Remove all refs to ARM64 as it will be shared with ARM32.

---
 drivers/cpuidle/cpuidle-arm64.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)
drivers/cpuidle/cpuidle-arm64.c +17 -17
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);
Signature · 1 line
1.9.1
Acked-by on v3 5/8
#8 lore raw

Re: [PATCH V3 5/8] ARM64: cpuidle: Remove arm64 reference

Quoted 6 lines · Daniel Lezcano

In the next patch, this driver will be common across ARM/ARM64. Remove all refs to ARM64 as it will be shared with ARM32.

Quoted 115 lines
---
 drivers/cpuidle/cpuidle-arm64.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)
drivers/cpuidle/cpuidle-arm64.c +17 -17
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);
Signature · 1 line
1.9.1
#9 lore raw

PATCH v3 6/8 ARM: cpuidle: Enable the ARM64 driver for both ARM32/ARM64

In reply to Daniel Lezcano

ARM32 and ARM64 have the same DT definitions and the same approaches.

The generic ARM cpuidle driver can be put in common for those two architectures.

---
 drivers/cpuidle/Kconfig                            |  7 +------
 drivers/cpuidle/Kconfig.arm                        | 12 +++++++++++-
 drivers/cpuidle/Kconfig.arm64                      | 13 -------------
 drivers/cpuidle/Makefile                           |  5 +----
 drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} |  0
 5 files changed, 13 insertions(+), 24 deletions(-)
 delete mode 100644 drivers/cpuidle/Kconfig.arm64
 rename drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} (100%)
drivers/cpuidle/Kconfig +1 -6
index c5029c1..8c7930b 100644
@@ -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 +11 -1
index 8e07c94..1f067bd 100644
@@ -14,6 +14,16 @@ config ARM_BIG_LITTLE_CPUIDLE
 	  define different C-states for little and big cores through the
 	  multiple CPU idle drivers infrastructure.
 
+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_CLPS711X_CPUIDLE
 	bool "CPU Idle Driver for CLPS711X processors"
 	depends on ARCH_CLPS711X || COMPILE_TEST
@@ -54,7 +64,7 @@ config ARM_AT91_CPUIDLE
 
 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
drivers/cpuidle/Kconfig.arm64 deleted +0 -13
deleted file mode 100644
index 6effb36..0000000
@@ -1,13 +0,0 @@
-#
-# 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 +1 -4
index 4d177b9..3ba81b1 100644
@@ -17,16 +17,13 @@ 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
 obj-$(CONFIG_POWERNV_CPUIDLE)		+= cpuidle-powernv.o
drivers/cpuidle/cpuidle-arm.c renamed from drivers/cpuidle/cpuidle-arm64.c +0 -0
similarity index 100%
rename from drivers/cpuidle/cpuidle-arm64.c
rename to drivers/cpuidle/cpuidle-arm.c
Signature · 1 line
1.9.1
Acked-by on v3 6/8
#10 lore raw

Re: [PATCH V3 6/8] ARM: cpuidle: Enable the ARM64 driver for both ARM32/ARM64

Quoted 23 lines · Daniel Lezcano

ARM32 and ARM64 have the same DT definitions and the same approaches.

The generic ARM cpuidle driver can be put in common for those two architectures.

---
 drivers/cpuidle/Kconfig                            |  7 +------
 drivers/cpuidle/Kconfig.arm                        | 12 +++++++++++-
 drivers/cpuidle/Kconfig.arm64                      | 13 -------------
 drivers/cpuidle/Makefile                           |  5 +----
 drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} |  0
 5 files changed, 13 insertions(+), 24 deletions(-)
 delete mode 100644 drivers/cpuidle/Kconfig.arm64
 rename drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} (100%)
drivers/cpuidle/Kconfig +0 -0
index c5029c1..8c7930b 100644

drivers/cpuidle/Kconfig config DT_IDLE_STATES · line 33

Quoted 6 lines
drivers/cpuidle/Kconfig +1 -1
@@ -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"

Risk here is pulling in arm drivers on arm64, maybe it is better to add a guard in Kconfig.arm to prevent pulling in ARM drivers (on ARM64) instead of just doing that for Exynos.

Quoted 15 lines
drivers/cpuidle/Kconfig +0 -5
 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 +0 -0
index 8e07c94..1f067bd 100644

drivers/cpuidle/Kconfig.arm config ARM_BIG_LITTLE_CPUIDLE · line 17

Quoted 4 lines
drivers/cpuidle/Kconfig.arm +1 -0
@@ -14,6 +14,16 @@ config ARM_BIG_LITTLE_CPUIDLE
 	  define different C-states for little and big cores through the
 	  multiple CPU idle drivers infrastructure.
 
+config ARM_CPUIDLE

You have to update the arm64 defconfig.

drivers/cpuidle/Kconfig.arm config ARM_BIG_LITTLE_CPUIDLE · line 29

Quoted 12 lines
drivers/cpuidle/Kconfig.arm +9 -0
+	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_CLPS711X_CPUIDLE
 	bool "CPU Idle Driver for CLPS711X processors"
 	depends on ARCH_CLPS711X || COMPILE_TEST

This for instance gets pulled in on allmodconfig on arm64, which is not useful and possibly noxious.

drivers/cpuidle/Kconfig.arm config ARM_AT91_CPUIDLE · line 67

Quoted 6 lines
drivers/cpuidle/Kconfig.arm +1 -1
@@ -54,7 +64,7 @@ config ARM_AT91_CPUIDLE
 
 config ARM_EXYNOS_CPUIDLE
 	bool "Cpu Idle Driver for the Exynos processors"
-	depends on ARCH_EXYNOS
+	depends on ARCH_EXYNOS && !ARM64

I would add a guard for all ARM drivers to prevent pulling them in on ARM64.

With the above changes:

Quoted 52 lines
drivers/cpuidle/Kconfig.arm +0 -0
 	select ARCH_NEEDS_CPU_IDLE_COUPLED if SMP
 	help
 	  Select this to enable cpuidle for Exynos processors
drivers/cpuidle/Kconfig.arm64 deleted +0 -13
deleted file mode 100644
index 6effb36..0000000
@@ -1,13 +0,0 @@
-#
-# 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 +1 -4
index 4d177b9..3ba81b1 100644
@@ -17,16 +17,13 @@ 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
 obj-$(CONFIG_POWERNV_CPUIDLE)		+= cpuidle-powernv.o
drivers/cpuidle/cpuidle-arm.c renamed from drivers/cpuidle/cpuidle-arm64.c +0 -0
similarity index 100%
rename from drivers/cpuidle/cpuidle-arm64.c
rename to drivers/cpuidle/cpuidle-arm.c
Signature · 1 line
1.9.1
#11 lore raw

PATCH v3 7/8 ARM: cpuidle: Register per cpuidle device

In reply to Daniel Lezcano

Some architectures have some cpus which does not support idle states.

Let the underlying low level code to return -ENXIO when it is not possible to set an idle state.

---
 drivers/cpuidle/cpuidle-arm.c | 42 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 40 insertions(+), 2 deletions(-)
drivers/cpuidle/cpuidle-arm.c +40 -2
index 1c94b88..e4a6eba 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 +107,54 @@ 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);
+
+		/* This cpu does not support any idle states */
+		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);
Signature · 1 line
1.9.1
#12 lore raw

Re: [PATCH V3 7/8] ARM: cpuidle: Register per cpuidle device

Quoted 4 lines · Daniel Lezcano

Some architectures have some cpus which does not support idle states.

Let the underlying low level code to return -ENXIO when it is not possible to set an idle state.

Well, this is getting interesting. We are parsing possible CPUs to detect if they have common idle states in DT. If a CPU does not support idle states, the cpu node for that CPU should not define any idle state.

The approach above will work with my heterogenous system patch, since the respective CPUidle driver mask will be created by parsing the DT idle states.

http://www.spinics.net/lists/arm-kernel/msg403190.html

In current approach if a "possible " CPU does not have idle states, we do not init CPUidle at all.

So, to cut a long story short, what does "a cpu does not support idle states" mean ?

Does it mean that firmware defines idle states for that CPU in DT but initializing them fail ?

I am fine with this patch, but we need to define -ENXIO return properly.

Quoted 34 lines
---
 drivers/cpuidle/cpuidle-arm.c | 42 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 40 insertions(+), 2 deletions(-)
drivers/cpuidle/cpuidle-arm.c +6 -0
index 1c94b88..e4a6eba 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 +107,54 @@ 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;

drivers/cpuidle/cpuidle-arm.c static int __init arm_idle_init(void) · line 123

Quoted 10 lines
drivers/cpuidle/cpuidle-arm.c +4 -0
+	}
+
 	/*
 	 * 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);
+
+		/* This cpu does not support any idle states */

We need to define what this means. If it means a cpu with no idle states in its cpu node the parsing would not even get here since to init the driver all possible cpus have to have the *same* idle states to function at present.

Lorenzo

Quoted 43 lines
drivers/cpuidle/cpuidle-arm.c +30 -2
+		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);
Signature · 1 line
1.9.1
#13 lore raw

Re: [PATCH V3 7/8] ARM: cpuidle: Register per cpuidle device

Quoted 20 lines · Lorenzo Pieralisi
Quoted 4 lines · Daniel Lezcano

Some architectures have some cpus which does not support idle states.

Let the underlying low level code to return -ENXIO when it is not possible to set an idle state.

Well, this is getting interesting. We are parsing possible CPUs to detect if they have common idle states in DT. If a CPU does not support idle states, the cpu node for that CPU should not define any idle state.

The approach above will work with my heterogenous system patch, since the respective CPUidle driver mask will be created by parsing the DT idle states.

http://www.spinics.net/lists/arm-kernel/msg403190.html

In current approach if a "possible " CPU does not have idle states, we do not init CPUidle at all.

Quoted 7 lines

So, to cut a long story short, what does "a cpu does not support idle states" mean ?

Does it mean that firmware defines idle states for that CPU in DT but initializing them fail ?

I am fine with this patch, but we need to define -ENXIO return properly.

Ok, I think that needs more discussion.

I will drop this patch from my patchset as we agreed on the other patches and resubmit.

-- Daniel

Signature · 5 lines
  <http://www.linaro.org/> Linaro.org ? Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
#14 lore raw

Re: [PATCH V3 7/8] ARM: cpuidle: Register per cpuidle device

In reply to Lorenzo Pieralisi
Quoted 20 lines · Lorenzo Pieralisi
Quoted 4 lines · Daniel Lezcano

Some architectures have some cpus which does not support idle states.

Let the underlying low level code to return -ENXIO when it is not possible to set an idle state.

Well, this is getting interesting. We are parsing possible CPUs to detect if they have common idle states in DT. If a CPU does not support idle states, the cpu node for that CPU should not define any idle state.

The approach above will work with my heterogenous system patch, since the respective CPUidle driver mask will be created by parsing the DT idle states.

http://www.spinics.net/lists/arm-kernel/msg403190.html

In current approach if a "possible " CPU does not have idle states, we do not init CPUidle at all.

Quoted 7 lines

So, to cut a long story short, what does "a cpu does not support idle states" mean ?

Does it mean that firmware defines idle states for that CPU in DT but initializing them fail ?

I am fine with this patch, but we need to define -ENXIO return properly.

Ok, so after discussing with Lina, it appears my change log is not correct.

In Qcom's platform, each core has a SPM. The device associated with this SPM is initialized before the cpuidle framework. If there is an error in the initialization (eg. error in the DT), the system continues to boot but in degraded mode as some SPM may not be correctly initialized. In this case, the EXNIO tells the cpuidle driver to not initialize the cpuidle device as the associated SPM is not operational. That prevents the system to crash and allows to handle the error gracefully.

Quoted 94 lines
Quoted 33 lines
---
  drivers/cpuidle/cpuidle-arm.c | 42 ++++++++++++++++++++++++++++++++++++++++--
  1 file changed, 40 insertions(+), 2 deletions(-)
drivers/cpuidle/cpuidle-arm.c +6 -0
index 1c94b88..e4a6eba 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 +107,54 @@ 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;

drivers/cpuidle/cpuidle-arm.c static int __init arm_idle_init(void) · line 123

Quoted 10 lines
drivers/cpuidle/cpuidle-arm.c +4 -0
+	}
+
  	/*
  	 * 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);
+
+		/* This cpu does not support any idle states */

We need to define what this means. If it means a cpu with no idle states in its cpu node the parsing would not even get here since to init the driver all possible cpus have to have the *same* idle states to function at present.

Lorenzo

Quoted 43 lines
drivers/cpuidle/cpuidle-arm.c +30 -3
+		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);
--

1.9.1

Signature · 5 lines
  <http://www.linaro.org/> Linaro.org ? Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
#15 lore raw

Re: [PATCH V3 7/8] ARM: cpuidle: Register per cpuidle device

Quoted 31 lines · Daniel Lezcano
Quoted 20 lines · Lorenzo Pieralisi
Quoted 4 lines · Daniel Lezcano

Some architectures have some cpus which does not support idle states.

Let the underlying low level code to return -ENXIO when it is not possible to set an idle state.

Well, this is getting interesting. We are parsing possible CPUs to detect if they have common idle states in DT. If a CPU does not support idle states, the cpu node for that CPU should not define any idle state.

The approach above will work with my heterogenous system patch, since the respective CPUidle driver mask will be created by parsing the DT idle states.

http://www.spinics.net/lists/arm-kernel/msg403190.html

In current approach if a "possible " CPU does not have idle states, we do not init CPUidle at all.

Quoted 7 lines

So, to cut a long story short, what does "a cpu does not support idle states" mean ?

Does it mean that firmware defines idle states for that CPU in DT but initializing them fail ?

I am fine with this patch, but we need to define -ENXIO return properly.

Ok, so after discussing with Lina, it appears my change log is not correct.

Quoted 7 lines

In Qcom's platform, each core has a SPM. The device associated with this SPM is initialized before the cpuidle framework. If there is an error in the initialization (eg. error in the DT), the system continues to boot but in degraded mode as some SPM may not be correctly initialized. In this case, the EXNIO tells the cpuidle driver to not initialize the cpuidle device as the associated SPM is not operational. That prevents the system to crash and allows to handle the error gracefully.

This makes more sense. I think that the whole cpu init idle code should be moved to arch code along with the DT idle states parsing, now we parse DT idle states in two code paths and that's prone to error, but I think that can be done later.

Lorenzo

Quoted 104 lines
Quoted 94 lines
Quoted 33 lines
---
  drivers/cpuidle/cpuidle-arm.c | 42 ++++++++++++++++++++++++++++++++++++++++--
  1 file changed, 40 insertions(+), 2 deletions(-)
drivers/cpuidle/cpuidle-arm.c +6 -0
index 1c94b88..e4a6eba 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 +107,54 @@ 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;

drivers/cpuidle/cpuidle-arm.c static int __init arm_idle_init(void) · line 123

Quoted 10 lines
drivers/cpuidle/cpuidle-arm.c +4 -0
+	}
+
  	/*
  	 * 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);
+
+		/* This cpu does not support any idle states */

We need to define what this means. If it means a cpu with no idle states in its cpu node the parsing would not even get here since to init the driver all possible cpus have to have the *same* idle states to function at present.

Lorenzo

Quoted 43 lines
drivers/cpuidle/cpuidle-arm.c +30 -3
+		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);
--

1.9.1

Signature · 5 lines
  <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
#16 lore raw

PATCH v4 1/1 ARM: cpuidle: Register per cpuidle device

On some platforms, the low level PM code may not be initialized correctly for a specific cpu. In this case, the EXNIO tells the cpuidle driver to not initialize the cpuidle device as the associated low level PM is not operational.

That prevents the system to crash and allows to handle the error gracefully.

For example, on Qcom's platform, each core has a SPM. The device associated with this SPM is initialized before the cpuidle framework. If there is an error in the initialization (eg. error in the DT), the system continues to boot but in degraded mode as some SPM may not be correctly initialized.

---
 drivers/cpuidle/cpuidle-arm.c | 46 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)
drivers/cpuidle/cpuidle-arm.c +44 -2
index 1c94b88..a7a01ce 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 +107,58 @@ 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);
+
+		/* 
+		 * Do not register the cpuidle device. This situation could
+		 * happen when the low level PM was not able to initialize
+		 * for any reaon.
+		 */
+		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);
Signature · 1 line
1.9.1
Acked-by on v4 1/1
#17 lore raw

Re: [PATCH V4] ARM: cpuidle: Register per cpuidle device

Quoted 2 lines · Daniel Lezcano

On some platforms, the low level PM code may not be initialized correctly for a specific cpu. In this case, the EXNIO tells the cpuidle driver to not

"-ENXIO", but honestly these sentences should be rewritten, I understand what you mean, but for someone who has not reviewed the code before this log means precious little.

"If the cpuidle init cpu operation returns -ENXIO, therefore reporting HW failure or misconfiguration, the CPUidle driver skips the respective cpuidle device initialization because the associated platform back-end HW is not operational".

Quoted 45 lines

initialize the cpuidle device as the associated low level PM is not operational.

That prevents the system to crash and allows to handle the error gracefully.

For example, on Qcom's platform, each core has a SPM. The device associated with this SPM is initialized before the cpuidle framework. If there is an error in the initialization (eg. error in the DT), the system continues to boot but in degraded mode as some SPM may not be correctly initialized.

---
 drivers/cpuidle/cpuidle-arm.c | 46 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)
drivers/cpuidle/cpuidle-arm.c +8 -0
index 1c94b88..a7a01ce 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 +107,58 @@ 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;
+	}
+
 	/*

drivers/cpuidle/cpuidle-arm.c static int __init arm_idle_init(void) · line 126

Quoted 10 lines
drivers/cpuidle/cpuidle-arm.c +5 -0
 	 * 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);
+
+		/* 
+		 * Do not register the cpuidle device. This situation could
+		 * happen when the low level PM was not able to initialize
+		 * for any reaon.

s/reaon/reason. I disagree, it is not for *any* reason. Something like:

/*
* Skip the cpuidle device initialization if the reported failure
* is a HW misconfiguration/breakage (-ENXIO).
*/

arm_cpuidle_init() should be documented in this respect.

Quoted 30 lines
drivers/cpuidle/cpuidle-arm.c +23 -2
+		 */
+		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) {

drivers/cpuidle/cpuidle-arm.c static int __init arm_idle_init(void) · line 164

Quoted 10 lines
drivers/cpuidle/cpuidle-arm.c +8 -0
+		dev = per_cpu(cpuidle_devices, cpu);
+		cpuidle_unregister_device(dev);
+		kfree(dev);
+	}
+
+	cpuidle_unregister_driver(drv);
+
+	return ret;
 }
 device_initcall(arm_idle_init);

With the changes requested:

#18 lore raw

PATCH v5 1/2 ARM: cpuidle: Register per cpuidle device

If the cpuidle init cpu operation returns -ENXIO, therefore reporting HW failure or misconfiguration, the CPUidle driver skips the respective cpuidle device initialization because the associated platform back-end HW is not operational.

That prevents the system to crash and allows to handle the error gracefully.

For example, on Qcom's platform, each core has a SPM. The device associated with this SPM is initialized before the cpuidle framework. If there is an error in the initialization (eg. error in the DT), the system continues to boot but in degraded mode as some SPM may not be correctly initialized.

---
 drivers/cpuidle/cpuidle-arm.c | 45 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 43 insertions(+), 2 deletions(-)
drivers/cpuidle/cpuidle-arm.c +43 -2
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);
Signature · 1 line
1.9.1
#19 lore raw

PATCH 2/2 ARM: cpuidle: Document the code

Add kernel-doc format documentation in the code.

---
 arch/arm/kernel/cpuidle.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
arch/arm/kernel/cpuidle.c +58 -0
index 2b0dae3..9219613 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 struct device node corresponding to a cpu node
+ * @cpu: the cpu identifier
+ *
+ * Get the method name defined in the 'enabled-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 enabled-method is defined, -EOPNOTSUPP if
+ * no cpuidle_ops is registered for the enabled-method.
+ */
 static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
 {
 	const char *enable_method;
@@ -75,6 +118,21 @@ 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 a enabled-method property,
+ *  -ENXIO if the HW reports a failure or a misconfiguration
+ */
 int __init arm_cpuidle_init(int cpu)
 {
 	struct device_node *cpu_node = of_cpu_device_node_get(cpu);
Signature · 1 line
1.9.1
Acked-by on v1 2/2
#20 lore raw

Re: [PATCH 2/2] ARM: cpuidle: Document the code

Quoted 12 lines · Daniel Lezcano

Add kernel-doc format documentation in the code.

---
 arch/arm/kernel/cpuidle.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
arch/arm/kernel/cpuidle.c +0 -0
index 2b0dae3..9219613 100644

arch/arm/kernel/cpuidle.c static const struct of_cpuidle_method __cpuidle_method_of_table_sentinel · line 24

Quoted 4 lines
arch/arm/kernel/cpuidle.c +1 -0
@@ -21,6 +21,17 @@ static const struct of_cpuidle_method __cpuidle_method_of_table_sentinel
 
 static struct cpuidle_ops cpuidle_ops[NR_CPUS];
 
+/*

You miss a star here to comply with kernel-doc (comment valid throughout the patch for all functions).

Quoted 47 lines
arch/arm/kernel/cpuidle.c +29 -0
+ * 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;

arch/arm/kernel/cpuidle.c static struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method) · line 86

Quoted 6 lines
arch/arm/kernel/cpuidle.c +3 -0
@@ -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 struct device node corresponding to a cpu node

It is a pointer, not a struct.

Quoted 20 lines
arch/arm/kernel/cpuidle.c +13 -0
+ * @cpu: the cpu identifier
+ *
+ * Get the method name defined in the 'enabled-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 enabled-method is defined, -EOPNOTSUPP if
+ * no cpuidle_ops is registered for the enabled-method.
+ */
 static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
 {
 	const char *enable_method;
@@ -75,6 +118,21 @@ 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

arch/arm/kernel/cpuidle.c static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu) · line 133

Quoted 10 lines
arch/arm/kernel/cpuidle.c +10 -0
+ *
+ * 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 a enabled-method property,

Ultra-nit: "an enabled-method"

arch/arm/kernel/cpuidle.c static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu) · line 134

Quoted 1 line
arch/arm/kernel/cpuidle.c +1 -0
+ *  -ENXIO if the HW reports a failure or a misconfiguration

-ENOMEM is missing.

Apart from these ultraminor changes (and thanks for putting it together):

Quoted 8 lines
arch/arm/kernel/cpuidle.c +1 -0
+ */
 int __init arm_cpuidle_init(int cpu)
 {
 	struct device_node *cpu_node = of_cpu_device_node_get(cpu);
Signature · 1 line
1.9.1
#21 lore raw

Re: [PATCH 2/2] ARM: cpuidle: Document the code

Quoted 1 line · Lorenzo Pieralisi

On Tue, Mar 24, 2015 at 09:54:02AM +0000, Daniel Lezcano wrote:

[...]

Quoted 14 lines
Quoted 9 lines

+/*
+ * 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:

Quoted 4 lines
+ *  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 a enabled-method property,
Quoted 1 line

Ultra-nit: "an enabled-method"

Bah, I cannot see the wood for the trees anymore. "an enable-method".

Lorenzo

#22 lore raw

Re: [PATCH 2/2] ARM: cpuidle: Document the code

In reply to Lorenzo Pieralisi
Quoted 5 lines · Lorenzo Pieralisi
Quoted 4 lines · Daniel Lezcano

Add kernel-doc format documentation in the code.

---

[ ... ]

Quoted 8 lines
Quoted 5 lines

+ * 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 a enabled-method property,

Ultra-nit: "an enabled-method"

Quoted 9 lines
Quoted 1 line

+ * -ENXIO if the HW reports a failure or a misconfiguration

-ENOMEM is missing.

Apart from these ultraminor changes (and thanks for putting it together):

Thanks for review Lorenzo. I fixed the comment and pushed in my tree for 4.1.

-- Daniel

Signature · 5 lines
  <http://www.linaro.org/> Linaro.org ? Open source software for ARM SoCs

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Acked-by on v5 1/2
#23 lore raw

Re: [PATCH V5 1/2] ARM: cpuidle: Register per cpuidle device

In reply to Daniel Lezcano
Quoted 5 lines · Daniel Lezcano

If the cpuidle init cpu operation returns -ENXIO, therefore reporting HW failure or misconfiguration, the CPUidle driver skips the respective cpuidle device initialization because the associated platform back-end HW is not operational.

Quoted 8 lines

That prevents the system to crash and allows to handle the error gracefully.

For example, on Qcom's platform, each core has a SPM. The device associated with this SPM is initialized before the cpuidle framework. If there is an error in the initialization (eg. error in the DT), the system continues to boot but in degraded mode as some SPM may not be correctly initialized.

Quoted 88 lines
---
 drivers/cpuidle/cpuidle-arm.c | 45 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 43 insertions(+), 2 deletions(-)
drivers/cpuidle/cpuidle-arm.c +43 -2
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);
Signature · 1 line
1.9.1
#24 lore raw

PATCH v3 8/8 ARM: cpuidle: Change function name to be consistent with x86

In reply to Daniel Lezcano

Change the functions name:
arm_cpuidle_suspend => arm_idle
arm_cpuidle_init => arm_idle_cpu_init

---
 arch/arm/include/asm/cpuidle.h   | 4 ++--
 arch/arm/kernel/cpuidle.c        | 4 ++--
 arch/arm64/include/asm/cpuidle.h | 6 +++---
 arch/arm64/kernel/cpuidle.c      | 2 +-
 drivers/cpuidle/cpuidle-arm.c    | 4 ++--
 5 files changed, 10 insertions(+), 10 deletions(-)
arch/arm/include/asm/cpuidle.h +2 -2
index 0f84249..5f547c0 100644
@@ -44,8 +44,8 @@ struct of_cpuidle_method {
 	__used __section(__cpuidle_method_of_table)			\
 	= { .method = _method, .ops = _ops }
 
-extern int arm_cpuidle_suspend(int index);
+extern int arm_idle(int index);
 
-extern int arm_cpuidle_init(int cpu);
+extern int arm_idle_cpu_init(int cpu);
 
 #endif
arch/arm/kernel/cpuidle.c +2 -2
index 7b42a40..05a2c3e 100644
@@ -29,7 +29,7 @@ int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
 	return index;
 }
 
-int arm_cpuidle_suspend(int index)
+int arm_idle(int index)
 {
 	int ret = -EOPNOTSUPP;
 	int cpu = smp_processor_id();
@@ -75,7 +75,7 @@ static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
 	return 0;
 }
 
-int __init arm_cpuidle_init(int cpu)
+int __init arm_idle_cpu_init(int cpu)
 {
 	int ret = -EOPNOTSUPP;
 	struct device_node *cpu_node = of_cpu_device_node_get(cpu);
arch/arm64/include/asm/cpuidle.h +3 -3
index 141b2fc..e9c0dc4e 100644
@@ -4,10 +4,10 @@
 #include <asm/proc-fns.h>
 
 #ifdef CONFIG_CPU_IDLE
-extern int arm_cpuidle_init(unsigned int cpu);
+extern int arm_idle_cpu_init(unsigned int cpu);
 extern int cpu_suspend(unsigned long arg);
 #else
-static inline int arm_cpuidle_init(unsigned int cpu)
+static inline int arm_idle_cpu_init(unsigned int cpu)
 {
 	return -EOPNOTSUPP;
 }
@@ -17,7 +17,7 @@ static inline int cpu_suspend(unsigned long arg)
 	return -EOPNOTSUPP;
 }
 #endif
-static inline int arm_cpuidle_suspend(int index)
+static inline int arm_idle(int index)
 {
 	return cpu_suspend(index);
 }
arch/arm64/kernel/cpuidle.c +1 -1
index a78143a..b6b4fcf 100644
@@ -15,7 +15,7 @@
 #include <asm/cpuidle.h>
 #include <asm/cpu_ops.h>
 
-int arm_cpuidle_init(unsigned int cpu)
+int arm_idle_cpu_init(unsigned int cpu)
 {
 	int ret = -EOPNOTSUPP;
 	struct device_node *cpu_node = of_cpu_device_node_get(cpu);
drivers/cpuidle/cpuidle-arm.c +2 -2
index e4a6eba..37c732d 100644
@@ -50,7 +50,7 @@ static int arm_enter_idle_state(struct cpuidle_device *dev,
 		 * call the CPU ops suspend protocol with idle index as a
 		 * parameter.
 		 */
-		arm_cpuidle_suspend(idx);
+		arm_idle(idx);
 
 		cpu_pm_exit();
 	}
@@ -118,7 +118,7 @@ static int __init arm_idle_init(void)
 	 * idle states suspend back-end specific data
 	 */
 	for_each_possible_cpu(cpu) {
-		ret = arm_cpuidle_init(cpu);
+		ret = arm_idle_cpu_init(cpu);
 
 		/* This cpu does not support any idle states */
 		if (ret == -ENXIO)
Signature · 1 line
1.9.1
#25 lore raw

Re: [PATCH V3 8/8] ARM: cpuidle: Change function name to be consistent with x86

Quoted 5 lines · Daniel Lezcano

Change the functions name:
arm_cpuidle_suspend => arm_idle
arm_cpuidle_init => arm_idle_cpu_init

I think you can drop this patch, unless we have a compelling reason to have same names with x86, sorry for the churn.

Lorenzo

Quoted 110 lines
---
 arch/arm/include/asm/cpuidle.h   | 4 ++--
 arch/arm/kernel/cpuidle.c        | 4 ++--
 arch/arm64/include/asm/cpuidle.h | 6 +++---
 arch/arm64/kernel/cpuidle.c      | 2 +-
 drivers/cpuidle/cpuidle-arm.c    | 4 ++--
 5 files changed, 10 insertions(+), 10 deletions(-)
arch/arm/include/asm/cpuidle.h +2 -2
index 0f84249..5f547c0 100644
@@ -44,8 +44,8 @@ struct of_cpuidle_method {
 	__used __section(__cpuidle_method_of_table)			\
 	= { .method = _method, .ops = _ops }
 
-extern int arm_cpuidle_suspend(int index);
+extern int arm_idle(int index);
 
-extern int arm_cpuidle_init(int cpu);
+extern int arm_idle_cpu_init(int cpu);
 
 #endif
arch/arm/kernel/cpuidle.c +2 -2
index 7b42a40..05a2c3e 100644
@@ -29,7 +29,7 @@ int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
 	return index;
 }
 
-int arm_cpuidle_suspend(int index)
+int arm_idle(int index)
 {
 	int ret = -EOPNOTSUPP;
 	int cpu = smp_processor_id();
@@ -75,7 +75,7 @@ static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
 	return 0;
 }
 
-int __init arm_cpuidle_init(int cpu)
+int __init arm_idle_cpu_init(int cpu)
 {
 	int ret = -EOPNOTSUPP;
 	struct device_node *cpu_node = of_cpu_device_node_get(cpu);
arch/arm64/include/asm/cpuidle.h +3 -3
index 141b2fc..e9c0dc4e 100644
@@ -4,10 +4,10 @@
 #include <asm/proc-fns.h>
 
 #ifdef CONFIG_CPU_IDLE
-extern int arm_cpuidle_init(unsigned int cpu);
+extern int arm_idle_cpu_init(unsigned int cpu);
 extern int cpu_suspend(unsigned long arg);
 #else
-static inline int arm_cpuidle_init(unsigned int cpu)
+static inline int arm_idle_cpu_init(unsigned int cpu)
 {
 	return -EOPNOTSUPP;
 }
@@ -17,7 +17,7 @@ static inline int cpu_suspend(unsigned long arg)
 	return -EOPNOTSUPP;
 }
 #endif
-static inline int arm_cpuidle_suspend(int index)
+static inline int arm_idle(int index)
 {
 	return cpu_suspend(index);
 }
arch/arm64/kernel/cpuidle.c +1 -1
index a78143a..b6b4fcf 100644
@@ -15,7 +15,7 @@
 #include <asm/cpuidle.h>
 #include <asm/cpu_ops.h>
 
-int arm_cpuidle_init(unsigned int cpu)
+int arm_idle_cpu_init(unsigned int cpu)
 {
 	int ret = -EOPNOTSUPP;
 	struct device_node *cpu_node = of_cpu_device_node_get(cpu);
drivers/cpuidle/cpuidle-arm.c +2 -2
index e4a6eba..37c732d 100644
@@ -50,7 +50,7 @@ static int arm_enter_idle_state(struct cpuidle_device *dev,
 		 * call the CPU ops suspend protocol with idle index as a
 		 * parameter.
 		 */
-		arm_cpuidle_suspend(idx);
+		arm_idle(idx);
 
 		cpu_pm_exit();
 	}
@@ -118,7 +118,7 @@ static int __init arm_idle_init(void)
 	 * idle states suspend back-end specific data
 	 */
 	for_each_possible_cpu(cpu) {
-		ret = arm_cpuidle_init(cpu);
+		ret = arm_idle_cpu_init(cpu);
 
 		/* This cpu does not support any idle states */
 		if (ret == -ENXIO)
Signature · 1 line
1.9.1
#26 lore raw
In reply to Daniel Lezcano

Hi Daniel,

Quoted 18 lines · Daniel Lezcano

There is a big number of cpuidle drivers for the ARM architecture.

These drivers have been cleaned up and grouped into the drivers/cpuidle directory to keep track of the changes more easily and ensure the code is following the same scheme across the drivers.

That had the benefit of simplifying the code and factor out a lot of common parts. Beside that, as the drivers belong to the 'drivers' directory, we had to split the arch specific bits and the generic code in order to keep everything self contained. The platform driver paradigm was used for this purpose.

Unfortunately, this approach is now no longer accepted and a different solution must be provided to reach the same goal: one example is the Qualcomm cpuidle driver upstreaming attempt.

In the meantime, ARM64 developed a generic cpuidle driver based on DT definition.

Quoted 8 lines

The DT definition provides an 'enable-method' to specify one of the cpu operations (PSCI, ...).

This patchset unify this driver with ARM32, using the same DT definition.

Thanks with this patchset we can use the 'enable-method' to specify a cpu operations, hence get rid of the platform driver approach and go further in the cpuidle driver flexibility via the DT.

I had a look and the series seems fine, if you have a branch I can pull from I will test on arm64 and add the required tags.

Thank you,
Lorenzo

#27 lore raw
Quoted 24 lines · Lorenzo Pieralisi

Hi Daniel,

Quoted 21 lines · Daniel Lezcano

There is a big number of cpuidle drivers for the ARM architecture.

These drivers have been cleaned up and grouped into the drivers/cpuidle directory to keep track of the changes more easily and ensure the code is following the same scheme across the drivers.

That had the benefit of simplifying the code and factor out a lot of common parts. Beside that, as the drivers belong to the 'drivers' directory, we had to split the arch specific bits and the generic code in order to keep everything self contained. The platform driver paradigm was used for this purpose.

Unfortunately, this approach is now no longer accepted and a different solution must be provided to reach the same goal: one example is the Qualcomm cpuidle driver upstreaming attempt.

In the meantime, ARM64 developed a generic cpuidle driver based on DT definition.

The DT definition provides an 'enable-method' to specify one of the cpu operations (PSCI, ...).

Quoted 8 lines
Quoted 5 lines

This patchset unify this driver with ARM32, using the same DT definition.

Thanks with this patchset we can use the 'enable-method' to specify a cpu operations, hence get rid of the platform driver approach and go further in the cpuidle driver flexibility via the DT.

I had a look and the series seems fine, if you have a branch I can pull from I will test on arm64 and add the required tags.

Yes, sure.

http://git.linaro.org/git-ro/people/daniel.lezcano/linux.git cpuidle/4.1

Thanks !

-- Daniel

Signature · 5 lines
  <http://www.linaro.org/> Linaro.org ? Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
#28 lore raw
In reply to Daniel Lezcano
Quoted 18 lines · Daniel Lezcano

There is a big number of cpuidle drivers for the ARM architecture.

These drivers have been cleaned up and grouped into the drivers/cpuidle directory to keep track of the changes more easily and ensure the code is following the same scheme across the drivers.

That had the benefit of simplifying the code and factor out a lot of common parts. Beside that, as the drivers belong to the 'drivers' directory, we had to split the arch specific bits and the generic code in order to keep everything self contained. The platform driver paradigm was used for this purpose.

Unfortunately, this approach is now no longer accepted and a different solution must be provided to reach the same goal: one example is the Qualcomm cpuidle driver upstreaming attempt.

In the meantime, ARM64 developed a generic cpuidle driver based on DT definition.

Quoted 8 lines

The DT definition provides an 'enable-method' to specify one of the cpu operations (PSCI, ...).

This patchset unify this driver with ARM32, using the same DT definition.

Thanks with this patchset we can use the 'enable-method' to specify a cpu operations, hence get rid of the platform driver approach and go further in the cpuidle driver flexibility via the DT.

I tested the series on arm64 FVP models, next week I will do it on Juno to cover arm64, but I do not expect any changes compared to FVP since the arm64 arch interface is identical (which is the goal BTW).

I will add the tag accordingly.

Lorenzo

Quoted 56 lines

Changelog:

V3:
* Fixed unroll loop when failing to register the device
* Removed the per cpu cpuidle_device
* Remove goto statement in the registration path
* Fixed a compilation failure with allyesconfig on arm64

V2:
* Used smp_operations style for cpuidle_ops
* Fixed some nits in the comments
* Added a patch to change the name of the functions
* Added per cpu device registration patch

Daniel Lezcano (8):
ARM: cpuidle: Remove duplicate header inclusion
ARM: cpuidle: Add a cpuidle ops structure to be used for DT
ARM64: cpuidle: Replace cpu_suspend by the common ARM/ARM64 function
ARM64: cpuidle: Rename cpu_init_idle to a common function name
ARM64: cpuidle: Remove arm64 reference
ARM: cpuidle: Enable the ARM64 driver for both ARM32/ARM64
ARM: cpuidle: Register per cpuidle device
ARM: cpuidle: Change function name to be consistent with x86

 arch/arm/include/asm/cpuidle.h                     | 23 +++++++
 arch/arm/kernel/cpuidle.c                          | 74 +++++++++++++++++++-
 arch/arm/mach-davinci/cpuidle.c                    |  1 -
 arch/arm/mach-imx/cpuidle-imx6q.c                  |  1 -
 arch/arm/mach-imx/cpuidle-imx6sl.c                 |  1 -
 arch/arm/mach-imx/cpuidle-imx6sx.c                 |  1 -
 arch/arm/mach-omap2/cpuidle44xx.c                  |  1 -
 arch/arm/mach-s3c64xx/cpuidle.c                    |  2 +-
 arch/arm/mach-tegra/cpuidle-tegra20.c              |  1 -
 arch/arm/mach-tegra/cpuidle-tegra30.c              |  1 -
 arch/arm64/include/asm/cpuidle.h                   |  9 ++-
 arch/arm64/kernel/cpuidle.c                        |  2 +-
 drivers/cpuidle/Kconfig                            |  7 +-
 drivers/cpuidle/Kconfig.arm                        | 12 +++-
 drivers/cpuidle/Kconfig.arm64                      | 13 ----
 drivers/cpuidle/Makefile                           |  5 +-
 drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} | 80 ++++++++++++++++------
 drivers/cpuidle/cpuidle-at91.c                     |  1 -
 drivers/cpuidle/cpuidle-exynos.c                   |  1 -
 drivers/cpuidle/cpuidle-kirkwood.c                 |  1 -
 drivers/cpuidle/cpuidle-ux500.c                    |  1 -
 drivers/cpuidle/cpuidle-zynq.c                     |  1 -
 include/asm-generic/vmlinux.lds.h                  |  2 +
 23 files changed, 178 insertions(+), 63 deletions(-)
 delete mode 100644 drivers/cpuidle/Kconfig.arm64
 rename drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} (57%)
Signature · 1 line
1.9.1
Tested-by on the v3 series
#29 lore raw
In reply to Daniel Lezcano
Quoted 18 lines · Daniel Lezcano

There is a big number of cpuidle drivers for the ARM architecture.

These drivers have been cleaned up and grouped into the drivers/cpuidle directory to keep track of the changes more easily and ensure the code is following the same scheme across the drivers.

That had the benefit of simplifying the code and factor out a lot of common parts. Beside that, as the drivers belong to the 'drivers' directory, we had to split the arch specific bits and the generic code in order to keep everything self contained. The platform driver paradigm was used for this purpose.

Unfortunately, this approach is now no longer accepted and a different solution must be provided to reach the same goal: one example is the Qualcomm cpuidle driver upstreaming attempt.

In the meantime, ARM64 developed a generic cpuidle driver based on DT definition.

Quoted 8 lines

The DT definition provides an 'enable-method' to specify one of the cpu operations (PSCI, ...).

This patchset unify this driver with ARM32, using the same DT definition.

Thanks with this patchset we can use the 'enable-method' to specify a cpu operations, hence get rid of the platform driver approach and go further in the cpuidle driver flexibility via the DT.

Tested on arm64 Juno and FVP models.

Quoted 56 lines

Changelog:

V3:
* Fixed unroll loop when failing to register the device
* Removed the per cpu cpuidle_device
* Remove goto statement in the registration path
* Fixed a compilation failure with allyesconfig on arm64

V2:
* Used smp_operations style for cpuidle_ops
* Fixed some nits in the comments
* Added a patch to change the name of the functions
* Added per cpu device registration patch

Daniel Lezcano (8):
ARM: cpuidle: Remove duplicate header inclusion
ARM: cpuidle: Add a cpuidle ops structure to be used for DT
ARM64: cpuidle: Replace cpu_suspend by the common ARM/ARM64 function
ARM64: cpuidle: Rename cpu_init_idle to a common function name
ARM64: cpuidle: Remove arm64 reference
ARM: cpuidle: Enable the ARM64 driver for both ARM32/ARM64
ARM: cpuidle: Register per cpuidle device
ARM: cpuidle: Change function name to be consistent with x86

 arch/arm/include/asm/cpuidle.h                     | 23 +++++++
 arch/arm/kernel/cpuidle.c                          | 74 +++++++++++++++++++-
 arch/arm/mach-davinci/cpuidle.c                    |  1 -
 arch/arm/mach-imx/cpuidle-imx6q.c                  |  1 -
 arch/arm/mach-imx/cpuidle-imx6sl.c                 |  1 -
 arch/arm/mach-imx/cpuidle-imx6sx.c                 |  1 -
 arch/arm/mach-omap2/cpuidle44xx.c                  |  1 -
 arch/arm/mach-s3c64xx/cpuidle.c                    |  2 +-
 arch/arm/mach-tegra/cpuidle-tegra20.c              |  1 -
 arch/arm/mach-tegra/cpuidle-tegra30.c              |  1 -
 arch/arm64/include/asm/cpuidle.h                   |  9 ++-
 arch/arm64/kernel/cpuidle.c                        |  2 +-
 drivers/cpuidle/Kconfig                            |  7 +-
 drivers/cpuidle/Kconfig.arm                        | 12 +++-
 drivers/cpuidle/Kconfig.arm64                      | 13 ----
 drivers/cpuidle/Makefile                           |  5 +-
 drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} | 80 ++++++++++++++++------
 drivers/cpuidle/cpuidle-at91.c                     |  1 -
 drivers/cpuidle/cpuidle-exynos.c                   |  1 -
 drivers/cpuidle/cpuidle-kirkwood.c                 |  1 -
 drivers/cpuidle/cpuidle-ux500.c                    |  1 -
 drivers/cpuidle/cpuidle-zynq.c                     |  1 -
 include/asm-generic/vmlinux.lds.h                  |  2 +
 23 files changed, 178 insertions(+), 63 deletions(-)
 delete mode 100644 drivers/cpuidle/Kconfig.arm64
 rename drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} (57%)
Signature · 1 line
1.9.1
author Applied
#30 lore raw
Quoted 22 lines · Lorenzo Pieralisi
Quoted 21 lines · Daniel Lezcano

There is a big number of cpuidle drivers for the ARM architecture.

These drivers have been cleaned up and grouped into the drivers/cpuidle directory to keep track of the changes more easily and ensure the code is following the same scheme across the drivers.

That had the benefit of simplifying the code and factor out a lot of common parts. Beside that, as the drivers belong to the 'drivers' directory, we had to split the arch specific bits and the generic code in order to keep everything self contained. The platform driver paradigm was used for this purpose.

Unfortunately, this approach is now no longer accepted and a different solution must be provided to reach the same goal: one example is the Qualcomm cpuidle driver upstreaming attempt.

In the meantime, ARM64 developed a generic cpuidle driver based on DT definition.

The DT definition provides an 'enable-method' to specify one of the cpu operations (PSCI, ...).

Quoted 7 lines
Quoted 5 lines

This patchset unify this driver with ARM32, using the same DT definition.

Thanks with this patchset we can use the 'enable-method' to specify a cpu operations, hence get rid of the platform driver approach and go further in the cpuidle driver flexibility via the DT.

Tested on arm64 Juno and FVP models.

Thanks Lorenzo for testing the patches.

I applied the series to my tree for 4.1.

-- Daniel

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Changelog:

V3:
* Fixed unroll loop when failing to register the device
* Removed the per cpu cpuidle_device
* Remove goto statement in the registration path
* Fixed a compilation failure with allyesconfig on arm64

V2:
* Used smp_operations style for cpuidle_ops
* Fixed some nits in the comments
* Added a patch to change the name of the functions
* Added per cpu device registration patch

Daniel Lezcano (8):
ARM: cpuidle: Remove duplicate header inclusion
ARM: cpuidle: Add a cpuidle ops structure to be used for DT
ARM64: cpuidle: Replace cpu_suspend by the common ARM/ARM64 function
ARM64: cpuidle: Rename cpu_init_idle to a common function name
ARM64: cpuidle: Remove arm64 reference
ARM: cpuidle: Enable the ARM64 driver for both ARM32/ARM64
ARM: cpuidle: Register per cpuidle device
ARM: cpuidle: Change function name to be consistent with x86

  arch/arm/include/asm/cpuidle.h                     | 23 +++++++
  arch/arm/kernel/cpuidle.c                          | 74 +++++++++++++++++++-
  arch/arm/mach-davinci/cpuidle.c                    |  1 -
  arch/arm/mach-imx/cpuidle-imx6q.c                  |  1 -
  arch/arm/mach-imx/cpuidle-imx6sl.c                 |  1 -
  arch/arm/mach-imx/cpuidle-imx6sx.c                 |  1 -
  arch/arm/mach-omap2/cpuidle44xx.c                  |  1 -
  arch/arm/mach-s3c64xx/cpuidle.c                    |  2 +-
  arch/arm/mach-tegra/cpuidle-tegra20.c              |  1 -
  arch/arm/mach-tegra/cpuidle-tegra30.c              |  1 -
  arch/arm64/include/asm/cpuidle.h                   |  9 ++-
  arch/arm64/kernel/cpuidle.c                        |  2 +-
  drivers/cpuidle/Kconfig                            |  7 +-
  drivers/cpuidle/Kconfig.arm                        | 12 +++-
  drivers/cpuidle/Kconfig.arm64                      | 13 ----
  drivers/cpuidle/Makefile                           |  5 +-
  drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} | 80 ++++++++++++++++------
  drivers/cpuidle/cpuidle-at91.c                     |  1 -
  drivers/cpuidle/cpuidle-exynos.c                   |  1 -
  drivers/cpuidle/cpuidle-kirkwood.c                 |  1 -
  drivers/cpuidle/cpuidle-ux500.c                    |  1 -
  drivers/cpuidle/cpuidle-zynq.c                     |  1 -
  include/asm-generic/vmlinux.lds.h                  |  2 +
  23 files changed, 178 insertions(+), 63 deletions(-)

delete mode 100644 drivers/cpuidle/Kconfig.arm64 rename drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} (57%)

--
1.9.1

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