Merge branch 'pm-cpuidle'
* pm-cpuidle:
cpuidle: Fix ARCH_NEEDS_CPU_IDLE_COUPLED dependency warning
cpuidle: Comment the driver's framework code
cpuidle: simplify multiple driver support
ARM: zynq: Add cpuidle support
cpuidle: improve governor Kconfig options
diff --git a/MAINTAINERS b/MAINTAINERS
index 95911af..1ad3d8c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1311,6 +1311,7 @@
T: git git://git.xilinx.com/linux-xlnx.git
S: Supported
F: arch/arm/mach-zynq/
+F: drivers/cpuidle/cpuidle-zynq.c
ARM64 PORT (AARCH64 ARCHITECTURE)
M: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index c4cc27e..81de5d9 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -1,7 +1,9 @@
-config CPU_IDLE
+menuconfig CPU_IDLE
bool "CPU idle PM support"
default y if ACPI || PPC_PSERIES
+ select CPU_IDLE_GOV_LADDER if (!NO_HZ && !NO_HZ_IDLE)
+ select CPU_IDLE_GOV_MENU if (NO_HZ || NO_HZ_IDLE)
help
CPU idle is a generic framework for supporting software-controlled
idle processor power management. It includes modular cross-platform
@@ -9,9 +11,10 @@
If you're using an ACPI-enabled platform, you should say Y here.
+if CPU_IDLE
+
config CPU_IDLE_MULTIPLE_DRIVERS
bool "Support multiple cpuidle drivers"
- depends on CPU_IDLE
default n
help
Allows the cpuidle framework to use different drivers for each CPU.
@@ -19,24 +22,26 @@
states. If unsure say N.
config CPU_IDLE_GOV_LADDER
- bool
- depends on CPU_IDLE
+ bool "Ladder governor (for periodic timer tick)"
default y
config CPU_IDLE_GOV_MENU
- bool
- depends on CPU_IDLE && NO_HZ
+ bool "Menu governor (for tickless system)"
default y
-config ARCH_NEEDS_CPU_IDLE_COUPLED
- def_bool n
-
-if CPU_IDLE
-
config CPU_IDLE_CALXEDA
bool "CPU Idle Driver for Calxeda processors"
depends on ARCH_HIGHBANK
help
Select this to enable cpuidle on Calxeda processors.
+config CPU_IDLE_ZYNQ
+ bool "CPU Idle Driver for Xilinx Zynq processors"
+ depends on ARCH_ZYNQ
+ help
+ Select this to enable cpuidle on Xilinx Zynq processors.
+
endif
+
+config ARCH_NEEDS_CPU_IDLE_COUPLED
+ def_bool n
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 0d8bd55..8767a7b 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -7,3 +7,4 @@
obj-$(CONFIG_CPU_IDLE_CALXEDA) += cpuidle-calxeda.o
obj-$(CONFIG_ARCH_KIRKWOOD) += cpuidle-kirkwood.o
+obj-$(CONFIG_CPU_IDLE_ZYNQ) += cpuidle-zynq.o
diff --git a/drivers/cpuidle/cpuidle-zynq.c b/drivers/cpuidle/cpuidle-zynq.c
new file mode 100644
index 0000000..38e03a1
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-zynq.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2012-2013 Xilinx
+ *
+ * CPU idle support for Xilinx Zynq
+ *
+ * based on arch/arm/mach-at91/cpuidle.c
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * The cpu idle uses wait-for-interrupt and RAM self refresh in order
+ * to implement two idle states -
+ * #1 wait-for-interrupt
+ * #2 wait-for-interrupt and RAM self refresh
+ *
+ * Maintainer: Michal Simek <michal.simek@xilinx.com>
+ */
+
+#include <linux/init.h>
+#include <linux/cpu_pm.h>
+#include <linux/cpuidle.h>
+#include <linux/of.h>
+#include <asm/proc-fns.h>
+#include <asm/cpuidle.h>
+
+#define ZYNQ_MAX_STATES 2
+
+/* Actual code that puts the SoC in different idle states */
+static int zynq_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{
+ /* Devices must be stopped here */
+ cpu_pm_enter();
+
+ /* Add code for DDR self refresh start */
+ cpu_do_idle();
+
+ /* Add code for DDR self refresh stop */
+ cpu_pm_exit();
+
+ return index;
+}
+
+static struct cpuidle_driver zynq_idle_driver = {
+ .name = "zynq_idle",
+ .owner = THIS_MODULE,
+ .states = {
+ ARM_CPUIDLE_WFI_STATE,
+ {
+ .enter = zynq_enter_idle,
+ .exit_latency = 10,
+ .target_residency = 10000,
+ .flags = CPUIDLE_FLAG_TIME_VALID |
+ CPUIDLE_FLAG_TIMER_STOP,
+ .name = "RAM_SR",
+ .desc = "WFI and RAM Self Refresh",
+ },
+ },
+ .safe_state_index = 0,
+ .state_count = ZYNQ_MAX_STATES,
+};
+
+/* Initialize CPU idle by registering the idle states */
+static int __init zynq_cpuidle_init(void)
+{
+ if (!of_machine_is_compatible("xlnx,zynq-7000"))
+ return -ENODEV;
+
+ pr_info("Xilinx Zynq CpuIdle Driver started\n");
+
+ return cpuidle_register(&zynq_idle_driver, NULL);
+}
+
+device_initcall(zynq_cpuidle_init);
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index c3a93fe..fdc432f 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -466,7 +466,7 @@
int cpu;
struct cpuidle_device *device;
- for_each_possible_cpu(cpu) {
+ for_each_cpu(cpu, drv->cpumask) {
device = &per_cpu(cpuidle_dev, cpu);
cpuidle_unregister_device(device);
}
@@ -498,7 +498,7 @@
return ret;
}
- for_each_possible_cpu(cpu) {
+ for_each_cpu(cpu, drv->cpumask) {
device = &per_cpu(cpuidle_dev, cpu);
device->cpu = cpu;
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index 8dfaaae..3ac499d 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -18,182 +18,249 @@
DEFINE_SPINLOCK(cpuidle_driver_lock);
-static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu);
-static struct cpuidle_driver * __cpuidle_get_cpu_driver(int cpu);
-
-static void cpuidle_setup_broadcast_timer(void *arg)
-{
- int cpu = smp_processor_id();
- clockevents_notify((long)(arg), &cpu);
-}
-
-static void __cpuidle_driver_init(struct cpuidle_driver *drv, int cpu)
-{
- int i;
-
- drv->refcnt = 0;
-
- for (i = drv->state_count - 1; i >= 0 ; i--) {
-
- if (!(drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP))
- continue;
-
- drv->bctimer = 1;
- on_each_cpu_mask(get_cpu_mask(cpu), cpuidle_setup_broadcast_timer,
- (void *)CLOCK_EVT_NOTIFY_BROADCAST_ON, 1);
- break;
- }
-}
-
-static int __cpuidle_register_driver(struct cpuidle_driver *drv, int cpu)
-{
- if (!drv || !drv->state_count)
- return -EINVAL;
-
- if (cpuidle_disabled())
- return -ENODEV;
-
- if (__cpuidle_get_cpu_driver(cpu))
- return -EBUSY;
-
- __cpuidle_driver_init(drv, cpu);
-
- __cpuidle_set_cpu_driver(drv, cpu);
-
- return 0;
-}
-
-static void __cpuidle_unregister_driver(struct cpuidle_driver *drv, int cpu)
-{
- if (drv != __cpuidle_get_cpu_driver(cpu))
- return;
-
- if (!WARN_ON(drv->refcnt > 0))
- __cpuidle_set_cpu_driver(NULL, cpu);
-
- if (drv->bctimer) {
- drv->bctimer = 0;
- on_each_cpu_mask(get_cpu_mask(cpu), cpuidle_setup_broadcast_timer,
- (void *)CLOCK_EVT_NOTIFY_BROADCAST_OFF, 1);
- }
-}
-
#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
static DEFINE_PER_CPU(struct cpuidle_driver *, cpuidle_drivers);
-static void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu)
-{
- per_cpu(cpuidle_drivers, cpu) = drv;
-}
-
+/**
+ * __cpuidle_get_cpu_driver - return the cpuidle driver tied to a CPU.
+ * @cpu: the CPU handled by the driver
+ *
+ * Returns a pointer to struct cpuidle_driver or NULL if no driver has been
+ * registered for @cpu.
+ */
static struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
{
return per_cpu(cpuidle_drivers, cpu);
}
-static void __cpuidle_unregister_all_cpu_driver(struct cpuidle_driver *drv)
+/**
+ * __cpuidle_unset_driver - unset per CPU driver variables.
+ * @drv: a valid pointer to a struct cpuidle_driver
+ *
+ * For each CPU in the driver's CPU mask, unset the registered driver per CPU
+ * variable. If @drv is different from the registered driver, the corresponding
+ * variable is not cleared.
+ */
+static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)
{
int cpu;
- for_each_present_cpu(cpu)
- __cpuidle_unregister_driver(drv, cpu);
+
+ for_each_cpu(cpu, drv->cpumask) {
+
+ if (drv != __cpuidle_get_cpu_driver(cpu))
+ continue;
+
+ per_cpu(cpuidle_drivers, cpu) = NULL;
+ }
}
-static int __cpuidle_register_all_cpu_driver(struct cpuidle_driver *drv)
+/**
+ * __cpuidle_set_driver - set per CPU driver variables the the given driver.
+ * @drv: a valid pointer to a struct cpuidle_driver
+ *
+ * For each CPU in the driver's cpumask, unset the registered driver per CPU
+ * to @drv.
+ *
+ * Returns 0 on success, -EBUSY if the CPUs have driver(s) already.
+ */
+static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)
{
- int ret = 0;
- int i, cpu;
+ int cpu;
- for_each_present_cpu(cpu) {
- ret = __cpuidle_register_driver(drv, cpu);
- if (ret)
- break;
- }
+ for_each_cpu(cpu, drv->cpumask) {
- if (ret)
- for_each_present_cpu(i) {
- if (i == cpu)
- break;
- __cpuidle_unregister_driver(drv, i);
+ if (__cpuidle_get_cpu_driver(cpu)) {
+ __cpuidle_unset_driver(drv);
+ return -EBUSY;
}
+ per_cpu(cpuidle_drivers, cpu) = drv;
+ }
- return ret;
+ return 0;
}
-int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu)
-{
- int ret;
-
- spin_lock(&cpuidle_driver_lock);
- ret = __cpuidle_register_driver(drv, cpu);
- spin_unlock(&cpuidle_driver_lock);
-
- return ret;
-}
-
-void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu)
-{
- spin_lock(&cpuidle_driver_lock);
- __cpuidle_unregister_driver(drv, cpu);
- spin_unlock(&cpuidle_driver_lock);
-}
-
-/**
- * cpuidle_register_driver - registers a driver
- * @drv: the driver
- */
-int cpuidle_register_driver(struct cpuidle_driver *drv)
-{
- int ret;
-
- spin_lock(&cpuidle_driver_lock);
- ret = __cpuidle_register_all_cpu_driver(drv);
- spin_unlock(&cpuidle_driver_lock);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(cpuidle_register_driver);
-
-/**
- * cpuidle_unregister_driver - unregisters a driver
- * @drv: the driver
- */
-void cpuidle_unregister_driver(struct cpuidle_driver *drv)
-{
- spin_lock(&cpuidle_driver_lock);
- __cpuidle_unregister_all_cpu_driver(drv);
- spin_unlock(&cpuidle_driver_lock);
-}
-EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);
-
#else
static struct cpuidle_driver *cpuidle_curr_driver;
-static inline void __cpuidle_set_cpu_driver(struct cpuidle_driver *drv, int cpu)
-{
- cpuidle_curr_driver = drv;
-}
-
+/**
+ * __cpuidle_get_cpu_driver - return the global cpuidle driver pointer.
+ * @cpu: ignored without the multiple driver support
+ *
+ * Return a pointer to a struct cpuidle_driver object or NULL if no driver was
+ * previously registered.
+ */
static inline struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
{
return cpuidle_curr_driver;
}
/**
+ * __cpuidle_set_driver - assign the global cpuidle driver variable.
+ * @drv: pointer to a struct cpuidle_driver object
+ *
+ * Returns 0 on success, -EBUSY if the driver is already registered.
+ */
+static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)
+{
+ if (cpuidle_curr_driver)
+ return -EBUSY;
+
+ cpuidle_curr_driver = drv;
+
+ return 0;
+}
+
+/**
+ * __cpuidle_unset_driver - unset the global cpuidle driver variable.
+ * @drv: a pointer to a struct cpuidle_driver
+ *
+ * Reset the global cpuidle variable to NULL. If @drv does not match the
+ * registered driver, do nothing.
+ */
+static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)
+{
+ if (drv == cpuidle_curr_driver)
+ cpuidle_curr_driver = NULL;
+}
+
+#endif
+
+/**
+ * cpuidle_setup_broadcast_timer - enable/disable the broadcast timer
+ * @arg: a void pointer used to match the SMP cross call API
+ *
+ * @arg is used as a value of type 'long' with on of the two values:
+ * - CLOCK_EVT_NOTIFY_BROADCAST_ON
+ * - CLOCK_EVT_NOTIFY_BROADCAST_OFF
+ *
+ * Set the broadcast timer notification for the current CPU. This function
+ * is executed per CPU by an SMP cross call. It not supposed to be called
+ * directly.
+ */
+static void cpuidle_setup_broadcast_timer(void *arg)
+{
+ int cpu = smp_processor_id();
+ clockevents_notify((long)(arg), &cpu);
+}
+
+/**
+ * __cpuidle_driver_init - initialize the driver's internal data
+ * @drv: a valid pointer to a struct cpuidle_driver
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+static int __cpuidle_driver_init(struct cpuidle_driver *drv)
+{
+ int i;
+
+ drv->refcnt = 0;
+
+ /*
+ * Use all possible CPUs as the default, because if the kernel boots
+ * with some CPUs offline and then we online one of them, the CPU
+ * notifier has to know which driver to assign.
+ */
+ if (!drv->cpumask)
+ drv->cpumask = (struct cpumask *)cpu_possible_mask;
+
+ /*
+ * Look for the timer stop flag in the different states, so that we know
+ * if the broadcast timer has to be set up. The loop is in the reverse
+ * order, because usually on of the the deeper states has this flag set.
+ */
+ for (i = drv->state_count - 1; i >= 0 ; i--) {
+
+ if (!(drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP))
+ continue;
+
+ drv->bctimer = 1;
+ break;
+ }
+
+ return 0;
+}
+
+/**
+ * __cpuidle_register_driver: register the driver
+ * @drv: a valid pointer to a struct cpuidle_driver
+ *
+ * Do some sanity checks, initialize the driver, assign the driver to the
+ * global cpuidle driver variable(s) and set up the broadcast timer if the
+ * cpuidle driver has some states that shut down the local timer.
+ *
+ * Returns 0 on success, a negative error code otherwise:
+ * * -EINVAL if the driver pointer is NULL or no idle states are available
+ * * -ENODEV if the cpuidle framework is disabled
+ * * -EBUSY if the driver is already assigned to the global variable(s)
+ */
+static int __cpuidle_register_driver(struct cpuidle_driver *drv)
+{
+ int ret;
+
+ if (!drv || !drv->state_count)
+ return -EINVAL;
+
+ if (cpuidle_disabled())
+ return -ENODEV;
+
+ ret = __cpuidle_driver_init(drv);
+ if (ret)
+ return ret;
+
+ ret = __cpuidle_set_driver(drv);
+ if (ret)
+ return ret;
+
+ if (drv->bctimer)
+ on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,
+ (void *)CLOCK_EVT_NOTIFY_BROADCAST_ON, 1);
+
+ return 0;
+}
+
+/**
+ * __cpuidle_unregister_driver - unregister the driver
+ * @drv: a valid pointer to a struct cpuidle_driver
+ *
+ * Check if the driver is no longer in use, reset the global cpuidle driver
+ * variable(s) and disable the timer broadcast notification mechanism if it was
+ * in use.
+ *
+ */
+static void __cpuidle_unregister_driver(struct cpuidle_driver *drv)
+{
+ if (WARN_ON(drv->refcnt > 0))
+ return;
+
+ if (drv->bctimer) {
+ drv->bctimer = 0;
+ on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,
+ (void *)CLOCK_EVT_NOTIFY_BROADCAST_OFF, 1);
+ }
+
+ __cpuidle_unset_driver(drv);
+}
+
+/**
* cpuidle_register_driver - registers a driver
- * @drv: the driver
+ * @drv: a pointer to a valid struct cpuidle_driver
+ *
+ * Register the driver under a lock to prevent concurrent attempts to
+ * [un]register the driver from occuring at the same time.
+ *
+ * Returns 0 on success, a negative error code (returned by
+ * __cpuidle_register_driver()) otherwise.
*/
int cpuidle_register_driver(struct cpuidle_driver *drv)
{
- int ret, cpu;
+ int ret;
- cpu = get_cpu();
spin_lock(&cpuidle_driver_lock);
- ret = __cpuidle_register_driver(drv, cpu);
+ ret = __cpuidle_register_driver(drv);
spin_unlock(&cpuidle_driver_lock);
- put_cpu();
return ret;
}
@@ -201,23 +268,24 @@
/**
* cpuidle_unregister_driver - unregisters a driver
- * @drv: the driver
+ * @drv: a pointer to a valid struct cpuidle_driver
+ *
+ * Unregisters the cpuidle driver under a lock to prevent concurrent attempts
+ * to [un]register the driver from occuring at the same time. @drv has to
+ * match the currently registered driver.
*/
void cpuidle_unregister_driver(struct cpuidle_driver *drv)
{
- int cpu;
-
- cpu = get_cpu();
spin_lock(&cpuidle_driver_lock);
- __cpuidle_unregister_driver(drv, cpu);
+ __cpuidle_unregister_driver(drv);
spin_unlock(&cpuidle_driver_lock);
- put_cpu();
}
EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);
-#endif
/**
- * cpuidle_get_driver - return the current driver
+ * cpuidle_get_driver - return the driver tied to the current CPU.
+ *
+ * Returns a struct cpuidle_driver pointer, or NULL if no driver is registered.
*/
struct cpuidle_driver *cpuidle_get_driver(void)
{
@@ -233,7 +301,11 @@
EXPORT_SYMBOL_GPL(cpuidle_get_driver);
/**
- * cpuidle_get_cpu_driver - return the driver tied with a cpu
+ * cpuidle_get_cpu_driver - return the driver registered for a CPU.
+ * @dev: a valid pointer to a struct cpuidle_device
+ *
+ * Returns a struct cpuidle_driver pointer, or NULL if no driver is registered
+ * for the CPU associated with @dev.
*/
struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev)
{
@@ -244,6 +316,14 @@
}
EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver);
+/**
+ * cpuidle_driver_ref - get a reference to the driver.
+ *
+ * Increment the reference counter of the cpuidle driver associated with
+ * the current CPU.
+ *
+ * Returns a pointer to the driver, or NULL if the current CPU has no driver.
+ */
struct cpuidle_driver *cpuidle_driver_ref(void)
{
struct cpuidle_driver *drv;
@@ -257,6 +337,12 @@
return drv;
}
+/**
+ * cpuidle_driver_unref - puts down the refcount for the driver
+ *
+ * Decrement the reference counter of the cpuidle driver associated with
+ * the current CPU.
+ */
void cpuidle_driver_unref(void)
{
struct cpuidle_driver *drv = cpuidle_get_driver();
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index 8f04062..0bc4b74 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -111,6 +111,9 @@
struct cpuidle_state states[CPUIDLE_STATE_MAX];
int state_count;
int safe_state_index;
+
+ /* the driver handles the cpus in cpumask */
+ struct cpumask *cpumask;
};
#ifdef CONFIG_CPU_IDLE
@@ -135,9 +138,6 @@
extern int cpuidle_play_dead(void);
extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev);
-extern int cpuidle_register_cpu_driver(struct cpuidle_driver *drv, int cpu);
-extern void cpuidle_unregister_cpu_driver(struct cpuidle_driver *drv, int cpu);
-
#else
static inline void disable_cpuidle(void) { }
static inline int cpuidle_idle_call(void) { return -ENODEV; }