[GIT PULL] : ARM cpuidle changes for 4.1

[GIT PULL] : ARM cpuidle changes for 4.1

[Daniel Lezcano]

Hi Rafael,

this PR request has the following content:

  - Removed the duplicate header inclusion (Daniel Lezcano).

  - Unified the generic cpuidle ARM driver with ARM64. Each platform can 
now define their 'enable-method' in the DT thus allowing to split the 
low level PM code from the generic cpuidle framework (Daniel Lezcano).

  - Allowed the generic ARM cpuidle driver to register per device and 
prevent to register the cpuidle device when the underlying hardware is 
misconfigured or an error occurs, thus allowing to fail gracefully 
(Daniel Lezcano).

Thanks !

   -- Daniel

The following changes since commit bc465aa9d045feb0e13b4a8f32cc33c1943f62d6:

   Linux 4.0-rc5 (2015-03-22 16:50:21 -0700)

are available in the git repository at:

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

for you to fetch changes up to 9a309d6fd213911321acbfe839e0bdb3a7a9f4bf:

   ARM: cpuidle: Document the code (2015-03-25 09:53:43 +0100)

----------------------------------------------------------------
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: Document the code

  arch/arm/include/asm/cpuidle.h                     |  23 
+++++++++++++++++++++++
  arch/arm/kernel/cpuidle.c                          | 133 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
  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/configs/defconfig                       |   2 +-
  arch/arm64/include/asm/cpuidle.h                   |   9 ++++++---
  arch/arm64/kernel/cpuidle.c                        |   2 +-
  drivers/cpuidle/Kconfig                            |   7 +------
  drivers/cpuidle/Kconfig.arm                        |  28 
+++++++++++++++++++---------
  drivers/cpuidle/Kconfig.arm64                      |  13 -------------
  drivers/cpuidle/Makefile                           |   5 +----
  drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} |  83 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------------------
  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 ++
  24 files changed, 249 insertions(+), 72 deletions(-)
  delete mode 100644 drivers/cpuidle/Kconfig.arm64
  rename drivers/cpuidle/{cpuidle-arm64.c => cpuidle-arm.c} (56%)

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[PATCH 1/8] ARM: cpuidle: Remove duplicate header inclusion

[Daniel Lezcano]

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.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 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(-)

diff --git a/arch/arm/include/asm/cpuidle.h b/arch/arm/include/asm/cpuidle.h
index af319ac..348dc81 100644
--- a/arch/arm/include/asm/cpuidle.h
+++ b/arch/arm/include/asm/cpuidle.h
@@ -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);
diff --git a/arch/arm/kernel/cpuidle.c b/arch/arm/kernel/cpuidle.c
index 89545f6..45969f8 100644
--- a/arch/arm/kernel/cpuidle.c
+++ b/arch/arm/kernel/cpuidle.c
@@ -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)
diff --git a/arch/arm/mach-davinci/cpuidle.c b/arch/arm/mach-davinci/cpuidle.c
index e365c1b..306ebc5 100644
--- a/arch/arm/mach-davinci/cpuidle.c
+++ b/arch/arm/mach-davinci/cpuidle.c
@@ -17,7 +17,6 @@
 #include <linux/cpuidle.h>
 #include <linux/io.h>
 #include <linux/export.h>
-#include <asm/proc-fns.h>
 #include <asm/cpuidle.h>
 
 #include <mach/cpuidle.h>
diff --git a/arch/arm/mach-imx/cpuidle-imx6q.c b/arch/arm/mach-imx/cpuidle-imx6q.c
index d76d086..8e21ccc 100644
--- a/arch/arm/mach-imx/cpuidle-imx6q.c
+++ b/arch/arm/mach-imx/cpuidle-imx6q.c
@@ -9,7 +9,6 @@
 #include <linux/cpuidle.h>
 #include <linux/module.h>
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 
 #include "common.h"
 #include "cpuidle.h"
diff --git a/arch/arm/mach-imx/cpuidle-imx6sl.c b/arch/arm/mach-imx/cpuidle-imx6sl.c
index 7d92e65..5742a9f 100644
--- a/arch/arm/mach-imx/cpuidle-imx6sl.c
+++ b/arch/arm/mach-imx/cpuidle-imx6sl.c
@@ -9,7 +9,6 @@
 #include <linux/cpuidle.h>
 #include <linux/module.h>
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 
 #include "common.h"
 #include "cpuidle.h"
diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c b/arch/arm/mach-imx/cpuidle-imx6sx.c
index 5a36722..2c9f1a8 100644
--- a/arch/arm/mach-imx/cpuidle-imx6sx.c
+++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
@@ -10,7 +10,6 @@
 #include <linux/cpu_pm.h>
 #include <linux/module.h>
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 #include <asm/suspend.h>
 
 #include "common.h"
diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c
index 01e398a..7622dbb 100644
--- a/arch/arm/mach-omap2/cpuidle44xx.c
+++ b/arch/arm/mach-omap2/cpuidle44xx.c
@@ -17,7 +17,6 @@
 #include <linux/clockchips.h>
 
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 
 #include "common.h"
 #include "pm.h"
diff --git a/arch/arm/mach-s3c64xx/cpuidle.c b/arch/arm/mach-s3c64xx/cpuidle.c
index 2eb0724..93aa8cb 100644
--- a/arch/arm/mach-s3c64xx/cpuidle.c
+++ b/arch/arm/mach-s3c64xx/cpuidle.c
@@ -16,7 +16,7 @@
 #include <linux/export.h>
 #include <linux/time.h>
 
-#include <asm/proc-fns.h>
+#include <asm/cpuidle.h>
 
 #include <mach/map.h>
 
diff --git a/arch/arm/mach-tegra/cpuidle-tegra20.c b/arch/arm/mach-tegra/cpuidle-tegra20.c
index 4f25a7c..e22b0d9 100644
--- a/arch/arm/mach-tegra/cpuidle-tegra20.c
+++ b/arch/arm/mach-tegra/cpuidle-tegra20.c
@@ -27,7 +27,6 @@
 #include <linux/module.h>
 
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
 
diff --git a/arch/arm/mach-tegra/cpuidle-tegra30.c b/arch/arm/mach-tegra/cpuidle-tegra30.c
index f8815ed..a2400ab4 100644
--- a/arch/arm/mach-tegra/cpuidle-tegra30.c
+++ b/arch/arm/mach-tegra/cpuidle-tegra30.c
@@ -27,7 +27,6 @@
 #include <linux/module.h>
 
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
 
diff --git a/drivers/cpuidle/cpuidle-at91.c b/drivers/cpuidle/cpuidle-at91.c
index aae7bfc..f2446c7 100644
--- a/drivers/cpuidle/cpuidle-at91.c
+++ b/drivers/cpuidle/cpuidle-at91.c
@@ -19,7 +19,6 @@
 #include <linux/cpuidle.h>
 #include <linux/io.h>
 #include <linux/export.h>
-#include <asm/proc-fns.h>
 #include <asm/cpuidle.h>
 
 #define AT91_MAX_STATES	2
diff --git a/drivers/cpuidle/cpuidle-exynos.c b/drivers/cpuidle/cpuidle-exynos.c
index 26f5f29..0c06ea2 100644
--- a/drivers/cpuidle/cpuidle-exynos.c
+++ b/drivers/cpuidle/cpuidle-exynos.c
@@ -19,7 +19,6 @@
 #include <linux/of.h>
 #include <linux/platform_data/cpuidle-exynos.h>
 
-#include <asm/proc-fns.h>
 #include <asm/suspend.h>
 #include <asm/cpuidle.h>
 
diff --git a/drivers/cpuidle/cpuidle-kirkwood.c b/drivers/cpuidle/cpuidle-kirkwood.c
index cea0a6c..d23d8f4 100644
--- a/drivers/cpuidle/cpuidle-kirkwood.c
+++ b/drivers/cpuidle/cpuidle-kirkwood.c
@@ -21,7 +21,6 @@
 #include <linux/cpuidle.h>
 #include <linux/io.h>
 #include <linux/export.h>
-#include <asm/proc-fns.h>
 #include <asm/cpuidle.h>
 
 #define KIRKWOOD_MAX_STATES	2
diff --git a/drivers/cpuidle/cpuidle-ux500.c b/drivers/cpuidle/cpuidle-ux500.c
index 66f81e4..8bf895c 100644
--- a/drivers/cpuidle/cpuidle-ux500.c
+++ b/drivers/cpuidle/cpuidle-ux500.c
@@ -19,7 +19,6 @@
 #include <linux/platform_device.h>
 
 #include <asm/cpuidle.h>
-#include <asm/proc-fns.h>
 
 static atomic_t master = ATOMIC_INIT(0);
 static DEFINE_SPINLOCK(master_lock);
diff --git a/drivers/cpuidle/cpuidle-zynq.c b/drivers/cpuidle/cpuidle-zynq.c
index 002b8c9..543292b 100644
--- a/drivers/cpuidle/cpuidle-zynq.c
+++ b/drivers/cpuidle/cpuidle-zynq.c
@@ -28,7 +28,6 @@
 #include <linux/init.h>
 #include <linux/cpuidle.h>
 #include <linux/platform_device.h>
-#include <asm/proc-fns.h>
 #include <asm/cpuidle.h>
 
 #define ZYNQ_MAX_STATES		2
-- 
1.9.1

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

[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.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Rob Herring <robherring2@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 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(-)

diff --git a/arch/arm/include/asm/cpuidle.h b/arch/arm/include/asm/cpuidle.h
index 348dc81..0f84249 100644
--- a/arch/arm/include/asm/cpuidle.h
+++ b/arch/arm/include/asm/cpuidle.h
@@ -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
diff --git a/arch/arm/kernel/cpuidle.c b/arch/arm/kernel/cpuidle.c
index 45969f8..2b0dae3 100644
--- a/arch/arm/kernel/cpuidle.c
+++ b/arch/arm/kernel/cpuidle.c
@@ -10,8 +10,17 @@
  */
 
 #include <linux/cpuidle.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 #include <asm/cpuidle.h>
 
+extern struct of_cpuidle_method __cpuidle_method_of_table[];
+
+static const struct of_cpuidle_method __cpuidle_method_of_table_sentinel
+	__used __section(__cpuidle_method_of_table_end);
+
+static struct cpuidle_ops cpuidle_ops[NR_CPUS];
+
 int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
 		struct cpuidle_driver *drv, int index)
 {
@@ -19,3 +28,66 @@ int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
 
 	return index;
 }
+
+int arm_cpuidle_suspend(int index)
+{
+	int ret = -EOPNOTSUPP;
+	int cpu = smp_processor_id();
+
+	if (cpuidle_ops[cpu].suspend)
+		ret = cpuidle_ops[cpu].suspend(cpu, index);
+
+	return ret;
+}
+
+static struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
+{
+	struct of_cpuidle_method *m = __cpuidle_method_of_table;
+
+	for (; m->method; m++)
+		if (!strcmp(m->method, method))
+			return m->ops;
+
+	return NULL;
+}
+
+static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
+{
+	const char *enable_method;
+	struct cpuidle_ops *ops;
+
+	enable_method = of_get_property(dn, "enable-method", NULL);
+	if (!enable_method)
+		return -ENOENT;
+
+	ops = arm_cpuidle_get_ops(enable_method);
+	if (!ops) {
+		pr_warn("%s: unsupported enable-method property: %s\n",
+			dn->full_name, enable_method);
+		return -EOPNOTSUPP;
+	}
+
+	cpuidle_ops[cpu] = *ops; /* structure copy */
+
+	pr_notice("cpuidle: enable-method property '%s'"
+		  " found operations\n", enable_method);
+
+	return 0;
+}
+
+int __init arm_cpuidle_init(int cpu)
+{
+	struct device_node *cpu_node = of_cpu_device_node_get(cpu);
+	int ret;
+
+	if (!cpu_node)
+		return -ENODEV;
+
+	ret = arm_cpuidle_read_ops(cpu_node, cpu);
+	if (!ret && cpuidle_ops[cpu].init)
+		ret = cpuidle_ops[cpu].init(cpu_node, cpu);
+
+	of_node_put(cpu_node);
+
+	return ret;
+}
diff --git a/arch/arm64/include/asm/cpuidle.h b/arch/arm64/include/asm/cpuidle.h
index c60643f..460a38b 100644
--- a/arch/arm64/include/asm/cpuidle.h
+++ b/arch/arm64/include/asm/cpuidle.h
@@ -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
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index ac78910..91c0930 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -167,6 +167,7 @@
 #define IOMMU_OF_TABLES()	OF_TABLE(CONFIG_OF_IOMMU, iommu)
 #define RESERVEDMEM_OF_TABLES()	OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem)
 #define CPU_METHOD_OF_TABLES()	OF_TABLE(CONFIG_SMP, cpu_method)
+#define CPUIDLE_METHOD_OF_TABLES() OF_TABLE(CONFIG_CPU_IDLE, cpuidle_method)
 #define EARLYCON_OF_TABLES()	OF_TABLE(CONFIG_SERIAL_EARLYCON, earlycon)
 
 #define KERNEL_DTB()							\
@@ -501,6 +502,7 @@
 	CLKSRC_OF_TABLES()						\
 	IOMMU_OF_TABLES()						\
 	CPU_METHOD_OF_TABLES()						\
+	CPUIDLE_METHOD_OF_TABLES()					\
 	KERNEL_DTB()							\
 	IRQCHIP_OF_MATCH_TABLE()					\
 	EARLYCON_OF_TABLES()
-- 
1.9.1

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

[Daniel Lezcano]

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

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Rob Herring <robherring2@gmail.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 drivers/cpuidle/cpuidle-arm64.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cpuidle/cpuidle-arm64.c b/drivers/cpuidle/cpuidle-arm64.c
index 39a2c62..0cea244 100644
--- a/drivers/cpuidle/cpuidle-arm64.c
+++ b/drivers/cpuidle/cpuidle-arm64.c
@@ -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();
 	}
-- 
1.9.1

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

[Daniel Lezcano]

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

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Rob Herring <robherring2@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 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(-)

diff --git a/arch/arm64/include/asm/cpuidle.h b/arch/arm64/include/asm/cpuidle.h
index 460a38b..141b2fc 100644
--- a/arch/arm64/include/asm/cpuidle.h
+++ b/arch/arm64/include/asm/cpuidle.h
@@ -4,10 +4,10 @@
 #include <asm/proc-fns.h>
 
 #ifdef CONFIG_CPU_IDLE
-extern int cpu_init_idle(unsigned int cpu);
+extern int arm_cpuidle_init(unsigned int cpu);
 extern int cpu_suspend(unsigned long arg);
 #else
-static inline int cpu_init_idle(unsigned int cpu)
+static inline int arm_cpuidle_init(unsigned int cpu)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/arch/arm64/kernel/cpuidle.c b/arch/arm64/kernel/cpuidle.c
index 5c08966..a78143a 100644
--- a/arch/arm64/kernel/cpuidle.c
+++ b/arch/arm64/kernel/cpuidle.c
@@ -15,7 +15,7 @@
 #include <asm/cpuidle.h>
 #include <asm/cpu_ops.h>
 
-int cpu_init_idle(unsigned int cpu)
+int arm_cpuidle_init(unsigned int cpu)
 {
 	int ret = -EOPNOTSUPP;
 	struct device_node *cpu_node = of_cpu_device_node_get(cpu);
diff --git a/drivers/cpuidle/cpuidle-arm64.c b/drivers/cpuidle/cpuidle-arm64.c
index 0cea244..6ef291c7 100644
--- a/drivers/cpuidle/cpuidle-arm64.c
+++ b/drivers/cpuidle/cpuidle-arm64.c
@@ -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;
-- 
1.9.1

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

[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.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Rob Herring <robherring2@gmail.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 drivers/cpuidle/cpuidle-arm64.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-arm64.c b/drivers/cpuidle/cpuidle-arm64.c
index 6ef291c7..1c94b88 100644
--- a/drivers/cpuidle/cpuidle-arm64.c
+++ b/drivers/cpuidle/cpuidle-arm64.c
@@ -1,5 +1,5 @@
 /*
- * ARM64 generic CPU idle driver.
+ * ARM/ARM64 generic CPU idle driver.
  *
  * Copyright (C) 2014 ARM Ltd.
  * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
@@ -9,7 +9,7 @@
  * published by the Free Software Foundation.
  */
 
-#define pr_fmt(fmt) "CPUidle arm64: " fmt
+#define pr_fmt(fmt) "CPUidle arm: " fmt
 
 #include <linux/cpuidle.h>
 #include <linux/cpumask.h>
@@ -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);
-- 
1.9.1

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

[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.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Acked-by: Rob Herring <robherring2@gmail.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 arch/arm64/configs/defconfig    |   2 +-
 drivers/cpuidle/Kconfig         |   7 +--
 drivers/cpuidle/Kconfig.arm     |  28 ++++++---
 drivers/cpuidle/Kconfig.arm64   |  13 -----
 drivers/cpuidle/Makefile        |   5 +-
 drivers/cpuidle/cpuidle-arm.c   | 122 ++++++++++++++++++++++++++++++++++++++++
 drivers/cpuidle/cpuidle-arm64.c | 122 ----------------------------------------
 7 files changed, 144 insertions(+), 155 deletions(-)
 delete mode 100644 drivers/cpuidle/Kconfig.arm64
 create mode 100644 drivers/cpuidle/cpuidle-arm.c
 delete mode 100644 drivers/cpuidle/cpuidle-arm64.c

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index be1f12a..af6a452 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -48,7 +48,7 @@ CONFIG_CMDLINE="console=ttyAMA0"
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
 CONFIG_COMPAT=y
 CONFIG_CPU_IDLE=y
-CONFIG_ARM64_CPUIDLE=y
+CONFIG_ARM_CPUIDLE=y
 CONFIG_NET=y
 CONFIG_PACKET=y
 CONFIG_UNIX=y
diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index c5029c1..8c7930b 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -29,15 +29,10 @@ config DT_IDLE_STATES
 	bool
 
 menu "ARM CPU Idle Drivers"
-depends on ARM
+depends on ARM || ARM64
 source "drivers/cpuidle/Kconfig.arm"
 endmenu
 
-menu "ARM64 CPU Idle Drivers"
-depends on ARM64
-source "drivers/cpuidle/Kconfig.arm64"
-endmenu
-
 menu "MIPS CPU Idle Drivers"
 depends on MIPS
 source "drivers/cpuidle/Kconfig.mips"
diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
index 8e07c94..21340e0 100644
--- a/drivers/cpuidle/Kconfig.arm
+++ b/drivers/cpuidle/Kconfig.arm
@@ -1,10 +1,20 @@
 #
 # ARM CPU Idle drivers
 #
+config ARM_CPUIDLE
+        bool "Generic ARM/ARM64 CPU idle Driver"
+        select DT_IDLE_STATES
+        help
+          Select this to enable generic cpuidle driver for ARM.
+          It provides a generic idle driver whose idle states are configured
+          at run-time through DT nodes. The CPUidle suspend backend is
+          initialized by calling the CPU operations init idle hook
+          provided by architecture code.
+
 config ARM_BIG_LITTLE_CPUIDLE
 	bool "Support for ARM big.LITTLE processors"
 	depends on ARCH_VEXPRESS_TC2_PM || ARCH_EXYNOS
-	depends on MCPM
+	depends on MCPM && !ARM64
 	select ARM_CPU_SUSPEND
 	select CPU_IDLE_MULTIPLE_DRIVERS
 	select DT_IDLE_STATES
@@ -16,51 +26,51 @@ config ARM_BIG_LITTLE_CPUIDLE
 
 config ARM_CLPS711X_CPUIDLE
 	bool "CPU Idle Driver for CLPS711X processors"
-	depends on ARCH_CLPS711X || COMPILE_TEST
+	depends on ARCH_CLPS711X && !ARM64 || COMPILE_TEST
 	help
 	  Select this to enable cpuidle on Cirrus Logic CLPS711X SOCs.
 
 config ARM_HIGHBANK_CPUIDLE
 	bool "CPU Idle Driver for Calxeda processors"
-	depends on ARM_PSCI
+	depends on ARM_PSCI && !ARM64
 	select ARM_CPU_SUSPEND
 	help
 	  Select this to enable cpuidle on Calxeda processors.
 
 config ARM_KIRKWOOD_CPUIDLE
 	bool "CPU Idle Driver for Marvell Kirkwood SoCs"
-	depends on MACH_KIRKWOOD
+	depends on MACH_KIRKWOOD && !ARM64
 	help
 	  This adds the CPU Idle driver for Marvell Kirkwood SoCs.
 
 config ARM_ZYNQ_CPUIDLE
 	bool "CPU Idle Driver for Xilinx Zynq processors"
-	depends on ARCH_ZYNQ
+	depends on ARCH_ZYNQ && !ARM64
 	help
 	  Select this to enable cpuidle on Xilinx Zynq processors.
 
 config ARM_U8500_CPUIDLE
 	bool "Cpu Idle Driver for the ST-E u8500 processors"
-	depends on ARCH_U8500
+	depends on ARCH_U8500 && !ARM64
 	help
 	  Select this to enable cpuidle for ST-E u8500 processors
 
 config ARM_AT91_CPUIDLE
 	bool "Cpu Idle Driver for the AT91 processors"
 	default y
-	depends on ARCH_AT91
+	depends on ARCH_AT91 && !ARM64
 	help
 	  Select this to enable cpuidle for AT91 processors
 
 config ARM_EXYNOS_CPUIDLE
 	bool "Cpu Idle Driver for the Exynos processors"
-	depends on ARCH_EXYNOS
+	depends on ARCH_EXYNOS && !ARM64
 	select ARCH_NEEDS_CPU_IDLE_COUPLED if SMP
 	help
 	  Select this to enable cpuidle for Exynos processors
 
 config ARM_MVEBU_V7_CPUIDLE
 	bool "CPU Idle Driver for mvebu v7 family processors"
-	depends on ARCH_MVEBU
+	depends on ARCH_MVEBU && !ARM64
 	help
 	  Select this to enable cpuidle on Armada 370, 38x and XP processors.
diff --git a/drivers/cpuidle/Kconfig.arm64 b/drivers/cpuidle/Kconfig.arm64
deleted file mode 100644
index 6effb36..0000000
--- a/drivers/cpuidle/Kconfig.arm64
+++ /dev/null
@@ -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.
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 4d177b9..3ba81b1 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -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
diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
new file mode 100644
index 0000000..1c94b88
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -0,0 +1,122 @@
+/*
+ * ARM/ARM64 generic CPU idle driver.
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) "CPUidle arm: " fmt
+
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <asm/cpuidle.h>
+
+#include "dt_idle_states.h"
+
+/*
+ * arm_enter_idle_state - Programs CPU to enter the specified state
+ *
+ * dev: cpuidle device
+ * drv: cpuidle driver
+ * idx: state index
+ *
+ * Called from the CPUidle framework to program the device to the
+ * specified target state selected by the governor.
+ */
+static int arm_enter_idle_state(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv, int idx)
+{
+	int ret;
+
+	if (!idx) {
+		cpu_do_idle();
+		return idx;
+	}
+
+	ret = cpu_pm_enter();
+	if (!ret) {
+		/*
+		 * Pass idle state index to cpu_suspend which in turn will
+		 * call the CPU ops suspend protocol with idle index as a
+		 * parameter.
+		 */
+		arm_cpuidle_suspend(idx);
+
+		cpu_pm_exit();
+	}
+
+	return ret ? -1 : idx;
+}
+
+static struct cpuidle_driver arm_idle_driver = {
+	.name = "arm_idle",
+	.owner = THIS_MODULE,
+	/*
+	 * State at index 0 is standby wfi and considered standard
+	 * on all ARM platforms. If in some platforms simple wfi
+	 * can't be used as "state 0", DT bindings must be implemented
+	 * to work around this issue and allow installing a special
+	 * handler for idle state index 0.
+	 */
+	.states[0] = {
+		.enter                  = arm_enter_idle_state,
+		.exit_latency           = 1,
+		.target_residency       = 1,
+		.power_usage		= UINT_MAX,
+		.name                   = "WFI",
+		.desc                   = "ARM WFI",
+	}
+};
+
+static const struct of_device_id arm_idle_state_match[] __initconst = {
+	{ .compatible = "arm,idle-state",
+	  .data = arm_enter_idle_state },
+	{ },
+};
+
+/*
+ * arm_idle_init
+ *
+ * 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 arm_idle_init(void)
+{
+	int cpu, ret;
+	struct cpuidle_driver *drv = &arm_idle_driver;
+
+	/*
+	 * Initialize idle states data, starting at index 1.
+	 * This driver is DT only, if no DT idle states are detected (ret == 0)
+	 * let the driver initialization fail accordingly since there is no
+	 * reason to initialize the idle driver if only wfi is supported.
+	 */
+	ret = dt_init_idle_driver(drv, arm_idle_state_match, 1);
+	if (ret <= 0)
+		return ret ? : -ENODEV;
+
+	/*
+	 * 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);
+		if (ret) {
+			pr_err("CPU %d failed to init idle CPU ops\n", cpu);
+			return ret;
+		}
+	}
+
+	return cpuidle_register(drv, NULL);
+}
+device_initcall(arm_idle_init);
diff --git a/drivers/cpuidle/cpuidle-arm64.c b/drivers/cpuidle/cpuidle-arm64.c
deleted file mode 100644
index 1c94b88..0000000
--- a/drivers/cpuidle/cpuidle-arm64.c
+++ /dev/null
@@ -1,122 +0,0 @@
-/*
- * ARM/ARM64 generic CPU idle driver.
- *
- * Copyright (C) 2014 ARM Ltd.
- * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#define pr_fmt(fmt) "CPUidle arm: " fmt
-
-#include <linux/cpuidle.h>
-#include <linux/cpumask.h>
-#include <linux/cpu_pm.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/of.h>
-
-#include <asm/cpuidle.h>
-
-#include "dt_idle_states.h"
-
-/*
- * arm_enter_idle_state - Programs CPU to enter the specified state
- *
- * dev: cpuidle device
- * drv: cpuidle driver
- * idx: state index
- *
- * Called from the CPUidle framework to program the device to the
- * specified target state selected by the governor.
- */
-static int arm_enter_idle_state(struct cpuidle_device *dev,
-				struct cpuidle_driver *drv, int idx)
-{
-	int ret;
-
-	if (!idx) {
-		cpu_do_idle();
-		return idx;
-	}
-
-	ret = cpu_pm_enter();
-	if (!ret) {
-		/*
-		 * Pass idle state index to cpu_suspend which in turn will
-		 * call the CPU ops suspend protocol with idle index as a
-		 * parameter.
-		 */
-		arm_cpuidle_suspend(idx);
-
-		cpu_pm_exit();
-	}
-
-	return ret ? -1 : idx;
-}
-
-static struct cpuidle_driver arm_idle_driver = {
-	.name = "arm_idle",
-	.owner = THIS_MODULE,
-	/*
-	 * State at index 0 is standby wfi and considered standard
-	 * on all ARM platforms. If in some platforms simple wfi
-	 * can't be used as "state 0", DT bindings must be implemented
-	 * to work around this issue and allow installing a special
-	 * handler for idle state index 0.
-	 */
-	.states[0] = {
-		.enter                  = arm_enter_idle_state,
-		.exit_latency           = 1,
-		.target_residency       = 1,
-		.power_usage		= UINT_MAX,
-		.name                   = "WFI",
-		.desc                   = "ARM WFI",
-	}
-};
-
-static const struct of_device_id arm_idle_state_match[] __initconst = {
-	{ .compatible = "arm,idle-state",
-	  .data = arm_enter_idle_state },
-	{ },
-};
-
-/*
- * arm_idle_init
- *
- * 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 arm_idle_init(void)
-{
-	int cpu, ret;
-	struct cpuidle_driver *drv = &arm_idle_driver;
-
-	/*
-	 * Initialize idle states data, starting at index 1.
-	 * This driver is DT only, if no DT idle states are detected (ret == 0)
-	 * let the driver initialization fail accordingly since there is no
-	 * reason to initialize the idle driver if only wfi is supported.
-	 */
-	ret = dt_init_idle_driver(drv, arm_idle_state_match, 1);
-	if (ret <= 0)
-		return ret ? : -ENODEV;
-
-	/*
-	 * 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);
-		if (ret) {
-			pr_err("CPU %d failed to init idle CPU ops\n", cpu);
-			return ret;
-		}
-	}
-
-	return cpuidle_register(drv, NULL);
-}
-device_initcall(arm_idle_init);
-- 
1.9.1

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

[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.

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.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 drivers/cpuidle/cpuidle-arm.c | 45 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 43 insertions(+), 2 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
index 1c94b88..545069d 100644
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -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);
-- 
1.9.1

[PATCH 8/8] ARM: cpuidle: Document the code

[Daniel Lezcano]

Add kernel-doc format documentation in the code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
---
 arch/arm/kernel/cpuidle.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/arch/arm/kernel/cpuidle.c b/arch/arm/kernel/cpuidle.c
index 2b0dae3..318da33 100644
--- a/arch/arm/kernel/cpuidle.c
+++ b/arch/arm/kernel/cpuidle.c
@@ -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);
-- 
1.9.1

Re: [GIT PULL] : ARM cpuidle changes for 4.1

[Rafael J. Wysocki]

On Wednesday, March 25, 2015 10:05:23 AM Daniel Lezcano wrote:
> 
> Hi Rafael,
> 
> this PR request has the following content:
> 
>   - Removed the duplicate header inclusion (Daniel Lezcano).
> 
>   - Unified the generic cpuidle ARM driver with ARM64. Each platform can 
> now define their 'enable-method' in the DT thus allowing to split the 
> low level PM code from the generic cpuidle framework (Daniel Lezcano).
> 
>   - Allowed the generic ARM cpuidle driver to register per device and 
> prevent to register the cpuidle device when the underlying hardware is 
> misconfigured or an error occurs, thus allowing to fail gracefully 
> (Daniel Lezcano).
> 
> Thanks !

Pulled, thanks!

Rafael

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

[Paul Bolle]

A few nits are all I spotted.

On Wed, 2015-03-25 at 10:07 +0100, Daniel Lezcano wrote:
> --- a/drivers/cpuidle/Kconfig.arm
> +++ b/drivers/cpuidle/Kconfig.arm

> +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.

Start with a tab instead of 8 spaces, please.

> --- /dev/null
> +++ b/drivers/cpuidle/cpuidle-arm.c

> +#include <linux/cpuidle.h>
> +#include <linux/cpumask.h>
> +#include <linux/cpu_pm.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>

Is this include actually needed? I haven't tried building this without
that include, but I spotted nothing obviously module related in this
file.

> +#include <linux/of.h>
> +
> +#include <asm/cpuidle.h>
> +
> +#include "dt_idle_states.h"

> +static struct cpuidle_driver arm_idle_driver = {
> +	.name = "arm_idle",
> +	.owner = THIS_MODULE,

Since this can only be built in, THIS_MODULE will (basically) be
equivalent to NULL according to include/linux/export.h. So I suppose
this line can be dropped.

> +	/*
> +	 * State at index 0 is standby wfi and considered standard
> +	 * on all ARM platforms. If in some platforms simple wfi
> +	 * can't be used as "state 0", DT bindings must be implemented
> +	 * to work around this issue and allow installing a special
> +	 * handler for idle state index 0.
> +	 */
> +	.states[0] = {
> +		.enter                  = arm_enter_idle_state,
> +		.exit_latency           = 1,
> +		.target_residency       = 1,
> +		.power_usage		= UINT_MAX,
> +		.name                   = "WFI",
> +		.desc                   = "ARM WFI",
> +	}
> +};

I did notice that these two nits are already present in
drivers/cpuidle/cpuidle-arm64.c. But since this patch is not just moving
that file's content around, you might as well look into those two nits.


Paul Bolle

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

[Daniel Lezcano]

On 03/25/2015 09:54 PM, Paul Bolle wrote:
> A few nits are all I spotted.
>
> On Wed, 2015-03-25 at 10:07 +0100, Daniel Lezcano wrote:
>> --- a/drivers/cpuidle/Kconfig.arm
>> +++ b/drivers/cpuidle/Kconfig.arm
>
>> +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.
>
> Start with a tab instead of 8 spaces, please.

Ok, I will send a fix for that on top of this patch.

>> --- /dev/null
>> +++ b/drivers/cpuidle/cpuidle-arm.c
>
>> +#include <linux/cpuidle.h>
>> +#include <linux/cpumask.h>
>> +#include <linux/cpu_pm.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>
> Is this include actually needed? I haven't tried building this without
> that include, but I spotted nothing obviously module related in this
> file.
>
>> +#include <linux/of.h>
>> +
>> +#include <asm/cpuidle.h>
>> +
>> +#include "dt_idle_states.h"
>
>> +static struct cpuidle_driver arm_idle_driver = {
>> +	.name = "arm_idle",
>> +	.owner = THIS_MODULE,
>
> Since this can only be built in, THIS_MODULE will (basically) be
> equivalent to NULL according to include/linux/export.h. So I suppose
> this line can be dropped.

Yeah, THIS_MODULE is present in all drivers. Very likely we can safely 
remove it.

>> +	/*
>> +	 * State at index 0 is standby wfi and considered standard
>> +	 * on all ARM platforms. If in some platforms simple wfi
>> +	 * can't be used as "state 0", DT bindings must be implemented
>> +	 * to work around this issue and allow installing a special
>> +	 * handler for idle state index 0.
>> +	 */
>> +	.states[0] = {
>> +		.enter                  = arm_enter_idle_state,
>> +		.exit_latency           = 1,
>> +		.target_residency       = 1,
>> +		.power_usage		= UINT_MAX,
>> +		.name                   = "WFI",
>> +		.desc                   = "ARM WFI",
>> +	}
>> +};
>
> I did notice that these two nits are already present in
> drivers/cpuidle/cpuidle-arm64.c. But since this patch is not just moving
> that file's content around, you might as well look into those two nits.

We can address the module code removal in a separate patchset as this is 
the case for all the drivers.


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