diff --git a/MAINTAINERS b/MAINTAINERS index 95911afa818f..1ad3d8c3ed83 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1311,6 +1311,7 @@ W: http://wiki.xilinx.com 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 diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig index c4cc27e5c8a5..81de5d96749b 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 @@ config CPU_IDLE 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 @@ config CPU_IDLE_MULTIPLE_DRIVERS 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 0d8bd55e776f..8767a7b3eb91 100644 --- a/drivers/cpuidle/Makefile +++ b/drivers/cpuidle/Makefile @@ -7,3 +7,4 @@ obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o obj-$(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 000000000000..38e03a183591 --- /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 . + * + * 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 + */ + +#include +#include +#include +#include +#include +#include + +#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 c3a93fece819..fdc432f18022 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -466,7 +466,7 @@ void cpuidle_unregister(struct cpuidle_driver *drv) 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 @@ int cpuidle_register(struct cpuidle_driver *drv, 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 8dfaaae94444..3ac499d5a207 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 @@ EXPORT_SYMBOL_GPL(cpuidle_register_driver); /** * 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 @@ struct cpuidle_driver *cpuidle_get_driver(void) 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 @@ struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev) } 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 @@ struct cpuidle_driver *cpuidle_driver_ref(void) 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 8f0406230a0a..0bc4b74668e9 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -111,6 +111,9 @@ struct cpuidle_driver { 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 void cpuidle_disable_device(struct cpuidle_device *dev); 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; }