From e8db0be1245de16a6cc6365506abc392c3c212d4 Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Thu, 25 Aug 2011 15:35:03 +0200 Subject: PM QoS: Move and rename the implementation files The PM QoS implementation files are better named kernel/power/qos.c and include/linux/pm_qos.h. The PM QoS support is compiled under the CONFIG_PM option. Signed-off-by: Jean Pihet Acked-by: markgross Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki --- arch/arm/mach-msm/clock.c | 2 +- drivers/acpi/processor_idle.c | 2 +- drivers/cpuidle/cpuidle.c | 2 +- drivers/cpuidle/governors/ladder.c | 2 +- drivers/cpuidle/governors/menu.c | 2 +- drivers/media/video/via-camera.c | 2 +- drivers/net/e1000e/netdev.c | 2 +- drivers/net/wireless/ipw2x00/ipw2100.c | 2 +- include/linux/netdevice.h | 2 +- include/linux/pm_qos.h | 61 +++++ include/linux/pm_qos_params.h | 38 --- include/sound/pcm.h | 2 +- kernel/Makefile | 2 +- kernel/pm_qos_params.c | 481 --------------------------------- kernel/power/Makefile | 2 +- kernel/power/qos.c | 481 +++++++++++++++++++++++++++++++++ net/mac80211/main.c | 2 +- net/mac80211/mlme.c | 2 +- net/mac80211/scan.c | 2 +- sound/core/pcm_native.c | 2 +- 20 files changed, 558 insertions(+), 535 deletions(-) create mode 100644 include/linux/pm_qos.h delete mode 100644 include/linux/pm_qos_params.h delete mode 100644 kernel/pm_qos_params.c create mode 100644 kernel/power/qos.c diff --git a/arch/arm/mach-msm/clock.c b/arch/arm/mach-msm/clock.c index 22a537669624..d9145dfc2a3b 100644 --- a/arch/arm/mach-msm/clock.c +++ b/arch/arm/mach-msm/clock.c @@ -18,7 +18,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 431ab11c8c1b..2e69e09ff03e 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -37,7 +37,7 @@ #include #include #include /* need_resched() */ -#include +#include #include #include #include diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index d4c542372886..0df014110097 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -12,7 +12,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c index 12c98900dcf8..f62fde21e962 100644 --- a/drivers/cpuidle/governors/ladder.c +++ b/drivers/cpuidle/governors/ladder.c @@ -14,7 +14,7 @@ #include #include -#include +#include #include #include diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index c47f3d09c1ee..3600f1955e48 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -12,7 +12,7 @@ #include #include -#include +#include #include #include #include diff --git a/drivers/media/video/via-camera.c b/drivers/media/video/via-camera.c index 85d3048c1d67..b3ca3893f3de 100644 --- a/drivers/media/video/via-camera.c +++ b/drivers/media/video/via-camera.c @@ -21,7 +21,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c index 2198e615f241..07031af38964 100644 --- a/drivers/net/e1000e/netdev.c +++ b/drivers/net/e1000e/netdev.c @@ -47,7 +47,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/drivers/net/wireless/ipw2x00/ipw2100.c b/drivers/net/wireless/ipw2x00/ipw2100.c index 3774dd034746..aaab76ce6020 100644 --- a/drivers/net/wireless/ipw2x00/ipw2100.c +++ b/drivers/net/wireless/ipw2x00/ipw2100.c @@ -161,7 +161,7 @@ that only one external action is invoked at a time. #include #include #include -#include +#include #include diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index ddee79bb8f15..f72ac6b972b7 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -31,7 +31,7 @@ #include #ifdef __KERNEL__ -#include +#include #include #include #include diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h new file mode 100644 index 000000000000..7ba675413b08 --- /dev/null +++ b/include/linux/pm_qos.h @@ -0,0 +1,61 @@ +#ifndef _LINUX_PM_QOS_H +#define _LINUX_PM_QOS_H +/* interface for the pm_qos_power infrastructure of the linux kernel. + * + * Mark Gross + */ +#include +#include +#include + +#define PM_QOS_RESERVED 0 +#define PM_QOS_CPU_DMA_LATENCY 1 +#define PM_QOS_NETWORK_LATENCY 2 +#define PM_QOS_NETWORK_THROUGHPUT 3 + +#define PM_QOS_NUM_CLASSES 4 +#define PM_QOS_DEFAULT_VALUE -1 + +#define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) +#define PM_QOS_NETWORK_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) +#define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0 + +struct pm_qos_request_list { + struct plist_node list; + int pm_qos_class; +}; + +#ifdef CONFIG_PM +void pm_qos_add_request(struct pm_qos_request_list *l, + int pm_qos_class, s32 value); +void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req, + s32 new_value); +void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req); + +int pm_qos_request(int pm_qos_class); +int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier); +int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier); +int pm_qos_request_active(struct pm_qos_request_list *req); +#else +static inline void pm_qos_add_request(struct pm_qos_request_list *l, + int pm_qos_class, s32 value) + { return; } +static inline void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req, + s32 new_value) + { return; } +static inline void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req) + { return; } + +static inline int pm_qos_request(int pm_qos_class) + { return 0; } +static inline int pm_qos_add_notifier(int pm_qos_class, + struct notifier_block *notifier) + { return 0; } +static inline int pm_qos_remove_notifier(int pm_qos_class, + struct notifier_block *notifier) + { return 0; } +static inline int pm_qos_request_active(struct pm_qos_request_list *req) + { return 0; } +#endif + +#endif diff --git a/include/linux/pm_qos_params.h b/include/linux/pm_qos_params.h deleted file mode 100644 index a7d87f911cab..000000000000 --- a/include/linux/pm_qos_params.h +++ /dev/null @@ -1,38 +0,0 @@ -#ifndef _LINUX_PM_QOS_PARAMS_H -#define _LINUX_PM_QOS_PARAMS_H -/* interface for the pm_qos_power infrastructure of the linux kernel. - * - * Mark Gross - */ -#include -#include -#include - -#define PM_QOS_RESERVED 0 -#define PM_QOS_CPU_DMA_LATENCY 1 -#define PM_QOS_NETWORK_LATENCY 2 -#define PM_QOS_NETWORK_THROUGHPUT 3 - -#define PM_QOS_NUM_CLASSES 4 -#define PM_QOS_DEFAULT_VALUE -1 - -#define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) -#define PM_QOS_NETWORK_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) -#define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0 - -struct pm_qos_request_list { - struct plist_node list; - int pm_qos_class; -}; - -void pm_qos_add_request(struct pm_qos_request_list *l, int pm_qos_class, s32 value); -void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req, - s32 new_value); -void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req); - -int pm_qos_request(int pm_qos_class); -int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier); -int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier); -int pm_qos_request_active(struct pm_qos_request_list *req); - -#endif diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 57e71fa33f7c..666ee91e8a2e 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -29,7 +29,7 @@ #include #include #include -#include +#include #define snd_pcm_substream_chip(substream) ((substream)->private_data) #define snd_pcm_chip(pcm) ((pcm)->private_data) diff --git a/kernel/Makefile b/kernel/Makefile index eca595e2fd52..2da48d3515eb 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -9,7 +9,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o \ rcupdate.o extable.o params.o posix-timers.o \ kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \ hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \ - notifier.o ksysfs.o pm_qos_params.o sched_clock.o cred.o \ + notifier.o ksysfs.o sched_clock.o cred.o \ async.o range.o obj-y += groups.o diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c deleted file mode 100644 index 37f05d0f0793..000000000000 --- a/kernel/pm_qos_params.c +++ /dev/null @@ -1,481 +0,0 @@ -/* - * This module exposes the interface to kernel space for specifying - * QoS dependencies. It provides infrastructure for registration of: - * - * Dependents on a QoS value : register requests - * Watchers of QoS value : get notified when target QoS value changes - * - * This QoS design is best effort based. Dependents register their QoS needs. - * Watchers register to keep track of the current QoS needs of the system. - * - * There are 3 basic classes of QoS parameter: latency, timeout, throughput - * each have defined units: - * latency: usec - * timeout: usec <-- currently not used. - * throughput: kbs (kilo byte / sec) - * - * There are lists of pm_qos_objects each one wrapping requests, notifiers - * - * User mode requests on a QOS parameter register themselves to the - * subsystem by opening the device node /dev/... and writing there request to - * the node. As long as the process holds a file handle open to the node the - * client continues to be accounted for. Upon file release the usermode - * request is removed and a new qos target is computed. This way when the - * request that the application has is cleaned up when closes the file - * pointer or exits the pm_qos_object will get an opportunity to clean up. - * - * Mark Gross - */ - -/*#define DEBUG*/ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include - -/* - * locking rule: all changes to requests or notifiers lists - * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock - * held, taken with _irqsave. One lock to rule them all - */ -enum pm_qos_type { - PM_QOS_MAX, /* return the largest value */ - PM_QOS_MIN /* return the smallest value */ -}; - -/* - * Note: The lockless read path depends on the CPU accessing - * target_value atomically. Atomic access is only guaranteed on all CPU - * types linux supports for 32 bit quantites - */ -struct pm_qos_object { - struct plist_head requests; - struct blocking_notifier_head *notifiers; - struct miscdevice pm_qos_power_miscdev; - char *name; - s32 target_value; /* Do not change to 64 bit */ - s32 default_value; - enum pm_qos_type type; -}; - -static DEFINE_SPINLOCK(pm_qos_lock); - -static struct pm_qos_object null_pm_qos; -static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); -static struct pm_qos_object cpu_dma_pm_qos = { - .requests = PLIST_HEAD_INIT(cpu_dma_pm_qos.requests), - .notifiers = &cpu_dma_lat_notifier, - .name = "cpu_dma_latency", - .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, - .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, - .type = PM_QOS_MIN, -}; - -static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); -static struct pm_qos_object network_lat_pm_qos = { - .requests = PLIST_HEAD_INIT(network_lat_pm_qos.requests), - .notifiers = &network_lat_notifier, - .name = "network_latency", - .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, - .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, - .type = PM_QOS_MIN -}; - - -static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); -static struct pm_qos_object network_throughput_pm_qos = { - .requests = PLIST_HEAD_INIT(network_throughput_pm_qos.requests), - .notifiers = &network_throughput_notifier, - .name = "network_throughput", - .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, - .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, - .type = PM_QOS_MAX, -}; - - -static struct pm_qos_object *pm_qos_array[] = { - &null_pm_qos, - &cpu_dma_pm_qos, - &network_lat_pm_qos, - &network_throughput_pm_qos -}; - -static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, - size_t count, loff_t *f_pos); -static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, - size_t count, loff_t *f_pos); -static int pm_qos_power_open(struct inode *inode, struct file *filp); -static int pm_qos_power_release(struct inode *inode, struct file *filp); - -static const struct file_operations pm_qos_power_fops = { - .write = pm_qos_power_write, - .read = pm_qos_power_read, - .open = pm_qos_power_open, - .release = pm_qos_power_release, - .llseek = noop_llseek, -}; - -/* unlocked internal variant */ -static inline int pm_qos_get_value(struct pm_qos_object *o) -{ - if (plist_head_empty(&o->requests)) - return o->default_value; - - switch (o->type) { - case PM_QOS_MIN: - return plist_first(&o->requests)->prio; - - case PM_QOS_MAX: - return plist_last(&o->requests)->prio; - - default: - /* runtime check for not using enum */ - BUG(); - } -} - -static inline s32 pm_qos_read_value(struct pm_qos_object *o) -{ - return o->target_value; -} - -static inline void pm_qos_set_value(struct pm_qos_object *o, s32 value) -{ - o->target_value = value; -} - -static void update_target(struct pm_qos_object *o, struct plist_node *node, - int del, int value) -{ - unsigned long flags; - int prev_value, curr_value; - - spin_lock_irqsave(&pm_qos_lock, flags); - prev_value = pm_qos_get_value(o); - /* PM_QOS_DEFAULT_VALUE is a signal that the value is unchanged */ - if (value != PM_QOS_DEFAULT_VALUE) { - /* - * to change the list, we atomically remove, reinit - * with new value and add, then see if the extremal - * changed - */ - plist_del(node, &o->requests); - plist_node_init(node, value); - plist_add(node, &o->requests); - } else if (del) { - plist_del(node, &o->requests); - } else { - plist_add(node, &o->requests); - } - curr_value = pm_qos_get_value(o); - pm_qos_set_value(o, curr_value); - spin_unlock_irqrestore(&pm_qos_lock, flags); - - if (prev_value != curr_value) - blocking_notifier_call_chain(o->notifiers, - (unsigned long)curr_value, - NULL); -} - -static int register_pm_qos_misc(struct pm_qos_object *qos) -{ - qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; - qos->pm_qos_power_miscdev.name = qos->name; - qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; - - return misc_register(&qos->pm_qos_power_miscdev); -} - -static int find_pm_qos_object_by_minor(int minor) -{ - int pm_qos_class; - - for (pm_qos_class = 0; - pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) { - if (minor == - pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor) - return pm_qos_class; - } - return -1; -} - -/** - * pm_qos_request - returns current system wide qos expectation - * @pm_qos_class: identification of which qos value is requested - * - * This function returns the current target value. - */ -int pm_qos_request(int pm_qos_class) -{ - return pm_qos_read_value(pm_qos_array[pm_qos_class]); -} -EXPORT_SYMBOL_GPL(pm_qos_request); - -int pm_qos_request_active(struct pm_qos_request_list *req) -{ - return req->pm_qos_class != 0; -} -EXPORT_SYMBOL_GPL(pm_qos_request_active); - -/** - * pm_qos_add_request - inserts new qos request into the list - * @dep: pointer to a preallocated handle - * @pm_qos_class: identifies which list of qos request to use - * @value: defines the qos request - * - * This function inserts a new entry in the pm_qos_class list of requested qos - * performance characteristics. It recomputes the aggregate QoS expectations - * for the pm_qos_class of parameters and initializes the pm_qos_request_list - * handle. Caller needs to save this handle for later use in updates and - * removal. - */ - -void pm_qos_add_request(struct pm_qos_request_list *dep, - int pm_qos_class, s32 value) -{ - struct pm_qos_object *o = pm_qos_array[pm_qos_class]; - int new_value; - - if (pm_qos_request_active(dep)) { - WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); - return; - } - if (value == PM_QOS_DEFAULT_VALUE) - new_value = o->default_value; - else - new_value = value; - plist_node_init(&dep->list, new_value); - dep->pm_qos_class = pm_qos_class; - update_target(o, &dep->list, 0, PM_QOS_DEFAULT_VALUE); -} -EXPORT_SYMBOL_GPL(pm_qos_add_request); - -/** - * pm_qos_update_request - modifies an existing qos request - * @pm_qos_req : handle to list element holding a pm_qos request to use - * @value: defines the qos request - * - * Updates an existing qos request for the pm_qos_class of parameters along - * with updating the target pm_qos_class value. - * - * Attempts are made to make this code callable on hot code paths. - */ -void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req, - s32 new_value) -{ - s32 temp; - struct pm_qos_object *o; - - if (!pm_qos_req) /*guard against callers passing in null */ - return; - - if (!pm_qos_request_active(pm_qos_req)) { - WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); - return; - } - - o = pm_qos_array[pm_qos_req->pm_qos_class]; - - if (new_value == PM_QOS_DEFAULT_VALUE) - temp = o->default_value; - else - temp = new_value; - - if (temp != pm_qos_req->list.prio) - update_target(o, &pm_qos_req->list, 0, temp); -} -EXPORT_SYMBOL_GPL(pm_qos_update_request); - -/** - * pm_qos_remove_request - modifies an existing qos request - * @pm_qos_req: handle to request list element - * - * Will remove pm qos request from the list of requests and - * recompute the current target value for the pm_qos_class. Call this - * on slow code paths. - */ -void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req) -{ - struct pm_qos_object *o; - - if (pm_qos_req == NULL) - return; - /* silent return to keep pcm code cleaner */ - - if (!pm_qos_request_active(pm_qos_req)) { - WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n"); - return; - } - - o = pm_qos_array[pm_qos_req->pm_qos_class]; - update_target(o, &pm_qos_req->list, 1, PM_QOS_DEFAULT_VALUE); - memset(pm_qos_req, 0, sizeof(*pm_qos_req)); -} -EXPORT_SYMBOL_GPL(pm_qos_remove_request); - -/** - * pm_qos_add_notifier - sets notification entry for changes to target value - * @pm_qos_class: identifies which qos target changes should be notified. - * @notifier: notifier block managed by caller. - * - * will register the notifier into a notification chain that gets called - * upon changes to the pm_qos_class target value. - */ -int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) -{ - int retval; - - retval = blocking_notifier_chain_register( - pm_qos_array[pm_qos_class]->notifiers, notifier); - - return retval; -} -EXPORT_SYMBOL_GPL(pm_qos_add_notifier); - -/** - * pm_qos_remove_notifier - deletes notification entry from chain. - * @pm_qos_class: identifies which qos target changes are notified. - * @notifier: notifier block to be removed. - * - * will remove the notifier from the notification chain that gets called - * upon changes to the pm_qos_class target value. - */ -int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) -{ - int retval; - - retval = blocking_notifier_chain_unregister( - pm_qos_array[pm_qos_class]->notifiers, notifier); - - return retval; -} -EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); - -static int pm_qos_power_open(struct inode *inode, struct file *filp) -{ - long pm_qos_class; - - pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); - if (pm_qos_class >= 0) { - struct pm_qos_request_list *req = kzalloc(sizeof(*req), GFP_KERNEL); - if (!req) - return -ENOMEM; - - pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); - filp->private_data = req; - - if (filp->private_data) - return 0; - } - return -EPERM; -} - -static int pm_qos_power_release(struct inode *inode, struct file *filp) -{ - struct pm_qos_request_list *req; - - req = filp->private_data; - pm_qos_remove_request(req); - kfree(req); - - return 0; -} - - -static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, - size_t count, loff_t *f_pos) -{ - s32 value; - unsigned long flags; - struct pm_qos_object *o; - struct pm_qos_request_list *pm_qos_req = filp->private_data; - - if (!pm_qos_req) - return -EINVAL; - if (!pm_qos_request_active(pm_qos_req)) - return -EINVAL; - - o = pm_qos_array[pm_qos_req->pm_qos_class]; - spin_lock_irqsave(&pm_qos_lock, flags); - value = pm_qos_get_value(o); - spin_unlock_irqrestore(&pm_qos_lock, flags); - - return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); -} - -static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, - size_t count, loff_t *f_pos) -{ - s32 value; - struct pm_qos_request_list *pm_qos_req; - - if (count == sizeof(s32)) { - if (copy_from_user(&value, buf, sizeof(s32))) - return -EFAULT; - } else if (count <= 11) { /* ASCII perhaps? */ - char ascii_value[11]; - unsigned long int ulval; - int ret; - - if (copy_from_user(ascii_value, buf, count)) - return -EFAULT; - - if (count > 10) { - if (ascii_value[10] == '\n') - ascii_value[10] = '\0'; - else - return -EINVAL; - } else { - ascii_value[count] = '\0'; - } - ret = strict_strtoul(ascii_value, 16, &ulval); - if (ret) { - pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret); - return -EINVAL; - } - value = (s32)lower_32_bits(ulval); - } else { - return -EINVAL; - } - - pm_qos_req = filp->private_data; - pm_qos_update_request(pm_qos_req, value); - - return count; -} - - -static int __init pm_qos_power_init(void) -{ - int ret = 0; - - ret = register_pm_qos_misc(&cpu_dma_pm_qos); - if (ret < 0) { - printk(KERN_ERR "pm_qos_param: cpu_dma_latency setup failed\n"); - return ret; - } - ret = register_pm_qos_misc(&network_lat_pm_qos); - if (ret < 0) { - printk(KERN_ERR "pm_qos_param: network_latency setup failed\n"); - return ret; - } - ret = register_pm_qos_misc(&network_throughput_pm_qos); - if (ret < 0) - printk(KERN_ERR - "pm_qos_param: network_throughput setup failed\n"); - - return ret; -} - -late_initcall(pm_qos_power_init); diff --git a/kernel/power/Makefile b/kernel/power/Makefile index c5ebc6a90643..ad6bdd8b401a 100644 --- a/kernel/power/Makefile +++ b/kernel/power/Makefile @@ -1,7 +1,7 @@ ccflags-$(CONFIG_PM_DEBUG) := -DDEBUG -obj-$(CONFIG_PM) += main.o +obj-$(CONFIG_PM) += main.o qos.o obj-$(CONFIG_PM_SLEEP) += console.o obj-$(CONFIG_FREEZER) += process.o obj-$(CONFIG_SUSPEND) += suspend.o diff --git a/kernel/power/qos.c b/kernel/power/qos.c new file mode 100644 index 000000000000..61b47384329e --- /dev/null +++ b/kernel/power/qos.c @@ -0,0 +1,481 @@ +/* + * This module exposes the interface to kernel space for specifying + * QoS dependencies. It provides infrastructure for registration of: + * + * Dependents on a QoS value : register requests + * Watchers of QoS value : get notified when target QoS value changes + * + * This QoS design is best effort based. Dependents register their QoS needs. + * Watchers register to keep track of the current QoS needs of the system. + * + * There are 3 basic classes of QoS parameter: latency, timeout, throughput + * each have defined units: + * latency: usec + * timeout: usec <-- currently not used. + * throughput: kbs (kilo byte / sec) + * + * There are lists of pm_qos_objects each one wrapping requests, notifiers + * + * User mode requests on a QOS parameter register themselves to the + * subsystem by opening the device node /dev/... and writing there request to + * the node. As long as the process holds a file handle open to the node the + * client continues to be accounted for. Upon file release the usermode + * request is removed and a new qos target is computed. This way when the + * request that the application has is cleaned up when closes the file + * pointer or exits the pm_qos_object will get an opportunity to clean up. + * + * Mark Gross + */ + +/*#define DEBUG*/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/* + * locking rule: all changes to requests or notifiers lists + * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock + * held, taken with _irqsave. One lock to rule them all + */ +enum pm_qos_type { + PM_QOS_MAX, /* return the largest value */ + PM_QOS_MIN /* return the smallest value */ +}; + +/* + * Note: The lockless read path depends on the CPU accessing + * target_value atomically. Atomic access is only guaranteed on all CPU + * types linux supports for 32 bit quantites + */ +struct pm_qos_object { + struct plist_head requests; + struct blocking_notifier_head *notifiers; + struct miscdevice pm_qos_power_miscdev; + char *name; + s32 target_value; /* Do not change to 64 bit */ + s32 default_value; + enum pm_qos_type type; +}; + +static DEFINE_SPINLOCK(pm_qos_lock); + +static struct pm_qos_object null_pm_qos; +static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); +static struct pm_qos_object cpu_dma_pm_qos = { + .requests = PLIST_HEAD_INIT(cpu_dma_pm_qos.requests), + .notifiers = &cpu_dma_lat_notifier, + .name = "cpu_dma_latency", + .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, + .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, + .type = PM_QOS_MIN, +}; + +static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); +static struct pm_qos_object network_lat_pm_qos = { + .requests = PLIST_HEAD_INIT(network_lat_pm_qos.requests), + .notifiers = &network_lat_notifier, + .name = "network_latency", + .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, + .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, + .type = PM_QOS_MIN +}; + + +static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); +static struct pm_qos_object network_throughput_pm_qos = { + .requests = PLIST_HEAD_INIT(network_throughput_pm_qos.requests), + .notifiers = &network_throughput_notifier, + .name = "network_throughput", + .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, + .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, + .type = PM_QOS_MAX, +}; + + +static struct pm_qos_object *pm_qos_array[] = { + &null_pm_qos, + &cpu_dma_pm_qos, + &network_lat_pm_qos, + &network_throughput_pm_qos +}; + +static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, + size_t count, loff_t *f_pos); +static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, + size_t count, loff_t *f_pos); +static int pm_qos_power_open(struct inode *inode, struct file *filp); +static int pm_qos_power_release(struct inode *inode, struct file *filp); + +static const struct file_operations pm_qos_power_fops = { + .write = pm_qos_power_write, + .read = pm_qos_power_read, + .open = pm_qos_power_open, + .release = pm_qos_power_release, + .llseek = noop_llseek, +}; + +/* unlocked internal variant */ +static inline int pm_qos_get_value(struct pm_qos_object *o) +{ + if (plist_head_empty(&o->requests)) + return o->default_value; + + switch (o->type) { + case PM_QOS_MIN: + return plist_first(&o->requests)->prio; + + case PM_QOS_MAX: + return plist_last(&o->requests)->prio; + + default: + /* runtime check for not using enum */ + BUG(); + } +} + +static inline s32 pm_qos_read_value(struct pm_qos_object *o) +{ + return o->target_value; +} + +static inline void pm_qos_set_value(struct pm_qos_object *o, s32 value) +{ + o->target_value = value; +} + +static void update_target(struct pm_qos_object *o, struct plist_node *node, + int del, int value) +{ + unsigned long flags; + int prev_value, curr_value; + + spin_lock_irqsave(&pm_qos_lock, flags); + prev_value = pm_qos_get_value(o); + /* PM_QOS_DEFAULT_VALUE is a signal that the value is unchanged */ + if (value != PM_QOS_DEFAULT_VALUE) { + /* + * to change the list, we atomically remove, reinit + * with new value and add, then see if the extremal + * changed + */ + plist_del(node, &o->requests); + plist_node_init(node, value); + plist_add(node, &o->requests); + } else if (del) { + plist_del(node, &o->requests); + } else { + plist_add(node, &o->requests); + } + curr_value = pm_qos_get_value(o); + pm_qos_set_value(o, curr_value); + spin_unlock_irqrestore(&pm_qos_lock, flags); + + if (prev_value != curr_value) + blocking_notifier_call_chain(o->notifiers, + (unsigned long)curr_value, + NULL); +} + +static int register_pm_qos_misc(struct pm_qos_object *qos) +{ + qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; + qos->pm_qos_power_miscdev.name = qos->name; + qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; + + return misc_register(&qos->pm_qos_power_miscdev); +} + +static int find_pm_qos_object_by_minor(int minor) +{ + int pm_qos_class; + + for (pm_qos_class = 0; + pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) { + if (minor == + pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor) + return pm_qos_class; + } + return -1; +} + +/** + * pm_qos_request - returns current system wide qos expectation + * @pm_qos_class: identification of which qos value is requested + * + * This function returns the current target value. + */ +int pm_qos_request(int pm_qos_class) +{ + return pm_qos_read_value(pm_qos_array[pm_qos_class]); +} +EXPORT_SYMBOL_GPL(pm_qos_request); + +int pm_qos_request_active(struct pm_qos_request_list *req) +{ + return req->pm_qos_class != 0; +} +EXPORT_SYMBOL_GPL(pm_qos_request_active); + +/** + * pm_qos_add_request - inserts new qos request into the list + * @dep: pointer to a preallocated handle + * @pm_qos_class: identifies which list of qos request to use + * @value: defines the qos request + * + * This function inserts a new entry in the pm_qos_class list of requested qos + * performance characteristics. It recomputes the aggregate QoS expectations + * for the pm_qos_class of parameters and initializes the pm_qos_request_list + * handle. Caller needs to save this handle for later use in updates and + * removal. + */ + +void pm_qos_add_request(struct pm_qos_request_list *dep, + int pm_qos_class, s32 value) +{ + struct pm_qos_object *o = pm_qos_array[pm_qos_class]; + int new_value; + + if (pm_qos_request_active(dep)) { + WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); + return; + } + if (value == PM_QOS_DEFAULT_VALUE) + new_value = o->default_value; + else + new_value = value; + plist_node_init(&dep->list, new_value); + dep->pm_qos_class = pm_qos_class; + update_target(o, &dep->list, 0, PM_QOS_DEFAULT_VALUE); +} +EXPORT_SYMBOL_GPL(pm_qos_add_request); + +/** + * pm_qos_update_request - modifies an existing qos request + * @pm_qos_req : handle to list element holding a pm_qos request to use + * @value: defines the qos request + * + * Updates an existing qos request for the pm_qos_class of parameters along + * with updating the target pm_qos_class value. + * + * Attempts are made to make this code callable on hot code paths. + */ +void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req, + s32 new_value) +{ + s32 temp; + struct pm_qos_object *o; + + if (!pm_qos_req) /*guard against callers passing in null */ + return; + + if (!pm_qos_request_active(pm_qos_req)) { + WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); + return; + } + + o = pm_qos_array[pm_qos_req->pm_qos_class]; + + if (new_value == PM_QOS_DEFAULT_VALUE) + temp = o->default_value; + else + temp = new_value; + + if (temp != pm_qos_req->list.prio) + update_target(o, &pm_qos_req->list, 0, temp); +} +EXPORT_SYMBOL_GPL(pm_qos_update_request); + +/** + * pm_qos_remove_request - modifies an existing qos request + * @pm_qos_req: handle to request list element + * + * Will remove pm qos request from the list of requests and + * recompute the current target value for the pm_qos_class. Call this + * on slow code paths. + */ +void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req) +{ + struct pm_qos_object *o; + + if (pm_qos_req == NULL) + return; + /* silent return to keep pcm code cleaner */ + + if (!pm_qos_request_active(pm_qos_req)) { + WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n"); + return; + } + + o = pm_qos_array[pm_qos_req->pm_qos_class]; + update_target(o, &pm_qos_req->list, 1, PM_QOS_DEFAULT_VALUE); + memset(pm_qos_req, 0, sizeof(*pm_qos_req)); +} +EXPORT_SYMBOL_GPL(pm_qos_remove_request); + +/** + * pm_qos_add_notifier - sets notification entry for changes to target value + * @pm_qos_class: identifies which qos target changes should be notified. + * @notifier: notifier block managed by caller. + * + * will register the notifier into a notification chain that gets called + * upon changes to the pm_qos_class target value. + */ +int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) +{ + int retval; + + retval = blocking_notifier_chain_register( + pm_qos_array[pm_qos_class]->notifiers, notifier); + + return retval; +} +EXPORT_SYMBOL_GPL(pm_qos_add_notifier); + +/** + * pm_qos_remove_notifier - deletes notification entry from chain. + * @pm_qos_class: identifies which qos target changes are notified. + * @notifier: notifier block to be removed. + * + * will remove the notifier from the notification chain that gets called + * upon changes to the pm_qos_class target value. + */ +int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) +{ + int retval; + + retval = blocking_notifier_chain_unregister( + pm_qos_array[pm_qos_class]->notifiers, notifier); + + return retval; +} +EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); + +static int pm_qos_power_open(struct inode *inode, struct file *filp) +{ + long pm_qos_class; + + pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); + if (pm_qos_class >= 0) { + struct pm_qos_request_list *req = kzalloc(sizeof(*req), GFP_KERNEL); + if (!req) + return -ENOMEM; + + pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE); + filp->private_data = req; + + if (filp->private_data) + return 0; + } + return -EPERM; +} + +static int pm_qos_power_release(struct inode *inode, struct file *filp) +{ + struct pm_qos_request_list *req; + + req = filp->private_data; + pm_qos_remove_request(req); + kfree(req); + + return 0; +} + + +static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, + size_t count, loff_t *f_pos) +{ + s32 value; + unsigned long flags; + struct pm_qos_object *o; + struct pm_qos_request_list *pm_qos_req = filp->private_data; + + if (!pm_qos_req) + return -EINVAL; + if (!pm_qos_request_active(pm_qos_req)) + return -EINVAL; + + o = pm_qos_array[pm_qos_req->pm_qos_class]; + spin_lock_irqsave(&pm_qos_lock, flags); + value = pm_qos_get_value(o); + spin_unlock_irqrestore(&pm_qos_lock, flags); + + return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); +} + +static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, + size_t count, loff_t *f_pos) +{ + s32 value; + struct pm_qos_request_list *pm_qos_req; + + if (count == sizeof(s32)) { + if (copy_from_user(&value, buf, sizeof(s32))) + return -EFAULT; + } else if (count <= 11) { /* ASCII perhaps? */ + char ascii_value[11]; + unsigned long int ulval; + int ret; + + if (copy_from_user(ascii_value, buf, count)) + return -EFAULT; + + if (count > 10) { + if (ascii_value[10] == '\n') + ascii_value[10] = '\0'; + else + return -EINVAL; + } else { + ascii_value[count] = '\0'; + } + ret = strict_strtoul(ascii_value, 16, &ulval); + if (ret) { + pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret); + return -EINVAL; + } + value = (s32)lower_32_bits(ulval); + } else { + return -EINVAL; + } + + pm_qos_req = filp->private_data; + pm_qos_update_request(pm_qos_req, value); + + return count; +} + + +static int __init pm_qos_power_init(void) +{ + int ret = 0; + + ret = register_pm_qos_misc(&cpu_dma_pm_qos); + if (ret < 0) { + printk(KERN_ERR "pm_qos_param: cpu_dma_latency setup failed\n"); + return ret; + } + ret = register_pm_qos_misc(&network_lat_pm_qos); + if (ret < 0) { + printk(KERN_ERR "pm_qos_param: network_latency setup failed\n"); + return ret; + } + ret = register_pm_qos_misc(&network_throughput_pm_qos); + if (ret < 0) + printk(KERN_ERR + "pm_qos_param: network_throughput setup failed\n"); + + return ret; +} + +late_initcall(pm_qos_power_init); diff --git a/net/mac80211/main.c b/net/mac80211/main.c index 866f269183cf..bb771e9f15bc 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -19,7 +19,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index d6470c7fd6ce..9604abc61a59 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -17,7 +17,7 @@ #include #include #include -#include +#include #include #include #include diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index 6f09eca01112..beefb0afefa1 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -14,7 +14,7 @@ #include #include -#include +#include #include #include #include diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 1c6be91dfb98..c74e228731ed 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -23,7 +23,7 @@ #include #include #include -#include +#include #include #include #include -- cgit v1.2.3-59-g8ed1b From cc74998618a66d34651c784dd02412614c3e81cc Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Thu, 25 Aug 2011 15:35:12 +0200 Subject: PM QoS: Minor clean-ups - Misc fixes to improve code readability: * rename struct pm_qos_request_list to struct pm_qos_request, * rename pm_qos_req parameter to req in internal code, consistenly use req in the API parameters, * update the in-kernel API callers to the new parameters names, * rename of fields names (requests, list, node, constraints) Signed-off-by: Jean Pihet Acked-by: markgross Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki --- drivers/media/video/via-camera.c | 2 +- drivers/net/wireless/ipw2x00/ipw2100.c | 2 +- include/linux/netdevice.h | 2 +- include/linux/pm_qos.h | 22 ++++----- include/sound/pcm.h | 2 +- kernel/power/qos.c | 88 +++++++++++++++++----------------- 6 files changed, 59 insertions(+), 59 deletions(-) diff --git a/drivers/media/video/via-camera.c b/drivers/media/video/via-camera.c index b3ca3893f3de..fba6c6458cf9 100644 --- a/drivers/media/video/via-camera.c +++ b/drivers/media/video/via-camera.c @@ -69,7 +69,7 @@ struct via_camera { struct mutex lock; enum viacam_opstate opstate; unsigned long flags; - struct pm_qos_request_list qos_request; + struct pm_qos_request qos_request; /* * GPIO info for power/reset management */ diff --git a/drivers/net/wireless/ipw2x00/ipw2100.c b/drivers/net/wireless/ipw2x00/ipw2100.c index aaab76ce6020..db35f99cac14 100644 --- a/drivers/net/wireless/ipw2x00/ipw2100.c +++ b/drivers/net/wireless/ipw2x00/ipw2100.c @@ -174,7 +174,7 @@ that only one external action is invoked at a time. #define DRV_DESCRIPTION "Intel(R) PRO/Wireless 2100 Network Driver" #define DRV_COPYRIGHT "Copyright(c) 2003-2006 Intel Corporation" -static struct pm_qos_request_list ipw2100_pm_qos_req; +static struct pm_qos_request ipw2100_pm_qos_req; /* Debugging stuff */ #ifdef CONFIG_IPW2100_DEBUG diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index f72ac6b972b7..f38ab5b7e768 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -964,7 +964,7 @@ struct net_device { */ char name[IFNAMSIZ]; - struct pm_qos_request_list pm_qos_req; + struct pm_qos_request pm_qos_req; /* device name hash chain */ struct hlist_node name_hlist; diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 7ba675413b08..6b0968f8bc6e 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -20,30 +20,30 @@ #define PM_QOS_NETWORK_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) #define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0 -struct pm_qos_request_list { - struct plist_node list; +struct pm_qos_request { + struct plist_node node; int pm_qos_class; }; #ifdef CONFIG_PM -void pm_qos_add_request(struct pm_qos_request_list *l, - int pm_qos_class, s32 value); -void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req, +void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, + s32 value); +void pm_qos_update_request(struct pm_qos_request *req, s32 new_value); -void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req); +void pm_qos_remove_request(struct pm_qos_request *req); int pm_qos_request(int pm_qos_class); int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier); -int pm_qos_request_active(struct pm_qos_request_list *req); +int pm_qos_request_active(struct pm_qos_request *req); #else -static inline void pm_qos_add_request(struct pm_qos_request_list *l, +static inline void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, s32 value) { return; } -static inline void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req, +static inline void pm_qos_update_request(struct pm_qos_request *req, s32 new_value) { return; } -static inline void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req) +static inline void pm_qos_remove_request(struct pm_qos_request *req) { return; } static inline int pm_qos_request(int pm_qos_class) @@ -54,7 +54,7 @@ static inline int pm_qos_add_notifier(int pm_qos_class, static inline int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) { return 0; } -static inline int pm_qos_request_active(struct pm_qos_request_list *req) +static inline int pm_qos_request_active(struct pm_qos_request *req) { return 0; } #endif diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 666ee91e8a2e..54cb079b7bf1 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -373,7 +373,7 @@ struct snd_pcm_substream { int number; char name[32]; /* substream name */ int stream; /* stream (direction) */ - struct pm_qos_request_list latency_pm_qos_req; /* pm_qos request */ + struct pm_qos_request latency_pm_qos_req; /* pm_qos request */ size_t buffer_bytes_max; /* limit ring buffer size */ struct snd_dma_buffer dma_buffer; unsigned int dma_buf_id; diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 61b47384329e..aa52c44e6080 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -45,7 +45,7 @@ #include /* - * locking rule: all changes to requests or notifiers lists + * locking rule: all changes to constraints or notifiers lists * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock * held, taken with _irqsave. One lock to rule them all */ @@ -60,7 +60,7 @@ enum pm_qos_type { * types linux supports for 32 bit quantites */ struct pm_qos_object { - struct plist_head requests; + struct plist_head constraints; struct blocking_notifier_head *notifiers; struct miscdevice pm_qos_power_miscdev; char *name; @@ -74,7 +74,7 @@ static DEFINE_SPINLOCK(pm_qos_lock); static struct pm_qos_object null_pm_qos; static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); static struct pm_qos_object cpu_dma_pm_qos = { - .requests = PLIST_HEAD_INIT(cpu_dma_pm_qos.requests), + .constraints = PLIST_HEAD_INIT(cpu_dma_pm_qos.constraints), .notifiers = &cpu_dma_lat_notifier, .name = "cpu_dma_latency", .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, @@ -84,7 +84,7 @@ static struct pm_qos_object cpu_dma_pm_qos = { static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); static struct pm_qos_object network_lat_pm_qos = { - .requests = PLIST_HEAD_INIT(network_lat_pm_qos.requests), + .constraints = PLIST_HEAD_INIT(network_lat_pm_qos.constraints), .notifiers = &network_lat_notifier, .name = "network_latency", .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, @@ -95,7 +95,7 @@ static struct pm_qos_object network_lat_pm_qos = { static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); static struct pm_qos_object network_throughput_pm_qos = { - .requests = PLIST_HEAD_INIT(network_throughput_pm_qos.requests), + .constraints = PLIST_HEAD_INIT(network_throughput_pm_qos.constraints), .notifiers = &network_throughput_notifier, .name = "network_throughput", .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, @@ -129,15 +129,15 @@ static const struct file_operations pm_qos_power_fops = { /* unlocked internal variant */ static inline int pm_qos_get_value(struct pm_qos_object *o) { - if (plist_head_empty(&o->requests)) + if (plist_head_empty(&o->constraints)) return o->default_value; switch (o->type) { case PM_QOS_MIN: - return plist_first(&o->requests)->prio; + return plist_first(&o->constraints)->prio; case PM_QOS_MAX: - return plist_last(&o->requests)->prio; + return plist_last(&o->constraints)->prio; default: /* runtime check for not using enum */ @@ -170,13 +170,13 @@ static void update_target(struct pm_qos_object *o, struct plist_node *node, * with new value and add, then see if the extremal * changed */ - plist_del(node, &o->requests); + plist_del(node, &o->constraints); plist_node_init(node, value); - plist_add(node, &o->requests); + plist_add(node, &o->constraints); } else if (del) { - plist_del(node, &o->requests); + plist_del(node, &o->constraints); } else { - plist_add(node, &o->requests); + plist_add(node, &o->constraints); } curr_value = pm_qos_get_value(o); pm_qos_set_value(o, curr_value); @@ -222,7 +222,7 @@ int pm_qos_request(int pm_qos_class) } EXPORT_SYMBOL_GPL(pm_qos_request); -int pm_qos_request_active(struct pm_qos_request_list *req) +int pm_qos_request_active(struct pm_qos_request *req) { return req->pm_qos_class != 0; } @@ -230,24 +230,24 @@ EXPORT_SYMBOL_GPL(pm_qos_request_active); /** * pm_qos_add_request - inserts new qos request into the list - * @dep: pointer to a preallocated handle + * @req: pointer to a preallocated handle * @pm_qos_class: identifies which list of qos request to use * @value: defines the qos request * * This function inserts a new entry in the pm_qos_class list of requested qos * performance characteristics. It recomputes the aggregate QoS expectations - * for the pm_qos_class of parameters and initializes the pm_qos_request_list + * for the pm_qos_class of parameters and initializes the pm_qos_request * handle. Caller needs to save this handle for later use in updates and * removal. */ -void pm_qos_add_request(struct pm_qos_request_list *dep, +void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, s32 value) { struct pm_qos_object *o = pm_qos_array[pm_qos_class]; int new_value; - if (pm_qos_request_active(dep)) { + if (pm_qos_request_active(req)) { WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); return; } @@ -255,15 +255,15 @@ void pm_qos_add_request(struct pm_qos_request_list *dep, new_value = o->default_value; else new_value = value; - plist_node_init(&dep->list, new_value); - dep->pm_qos_class = pm_qos_class; - update_target(o, &dep->list, 0, PM_QOS_DEFAULT_VALUE); + plist_node_init(&req->node, new_value); + req->pm_qos_class = pm_qos_class; + update_target(o, &req->node, 0, PM_QOS_DEFAULT_VALUE); } EXPORT_SYMBOL_GPL(pm_qos_add_request); /** * pm_qos_update_request - modifies an existing qos request - * @pm_qos_req : handle to list element holding a pm_qos request to use + * @req : handle to list element holding a pm_qos request to use * @value: defines the qos request * * Updates an existing qos request for the pm_qos_class of parameters along @@ -271,56 +271,56 @@ EXPORT_SYMBOL_GPL(pm_qos_add_request); * * Attempts are made to make this code callable on hot code paths. */ -void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req, +void pm_qos_update_request(struct pm_qos_request *req, s32 new_value) { s32 temp; struct pm_qos_object *o; - if (!pm_qos_req) /*guard against callers passing in null */ + if (!req) /*guard against callers passing in null */ return; - if (!pm_qos_request_active(pm_qos_req)) { + if (!pm_qos_request_active(req)) { WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); return; } - o = pm_qos_array[pm_qos_req->pm_qos_class]; + o = pm_qos_array[req->pm_qos_class]; if (new_value == PM_QOS_DEFAULT_VALUE) temp = o->default_value; else temp = new_value; - if (temp != pm_qos_req->list.prio) - update_target(o, &pm_qos_req->list, 0, temp); + if (temp != req->node.prio) + update_target(o, &req->node, 0, temp); } EXPORT_SYMBOL_GPL(pm_qos_update_request); /** * pm_qos_remove_request - modifies an existing qos request - * @pm_qos_req: handle to request list element + * @req: handle to request list element * - * Will remove pm qos request from the list of requests and + * Will remove pm qos request from the list of constraints and * recompute the current target value for the pm_qos_class. Call this * on slow code paths. */ -void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req) +void pm_qos_remove_request(struct pm_qos_request *req) { struct pm_qos_object *o; - if (pm_qos_req == NULL) + if (req == NULL) return; /* silent return to keep pcm code cleaner */ - if (!pm_qos_request_active(pm_qos_req)) { + if (!pm_qos_request_active(req)) { WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n"); return; } - o = pm_qos_array[pm_qos_req->pm_qos_class]; - update_target(o, &pm_qos_req->list, 1, PM_QOS_DEFAULT_VALUE); - memset(pm_qos_req, 0, sizeof(*pm_qos_req)); + o = pm_qos_array[req->pm_qos_class]; + update_target(o, &req->node, 1, PM_QOS_DEFAULT_VALUE); + memset(req, 0, sizeof(*req)); } EXPORT_SYMBOL_GPL(pm_qos_remove_request); @@ -368,7 +368,7 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp) pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); if (pm_qos_class >= 0) { - struct pm_qos_request_list *req = kzalloc(sizeof(*req), GFP_KERNEL); + struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL); if (!req) return -ENOMEM; @@ -383,7 +383,7 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp) static int pm_qos_power_release(struct inode *inode, struct file *filp) { - struct pm_qos_request_list *req; + struct pm_qos_request *req; req = filp->private_data; pm_qos_remove_request(req); @@ -399,14 +399,14 @@ static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, s32 value; unsigned long flags; struct pm_qos_object *o; - struct pm_qos_request_list *pm_qos_req = filp->private_data; + struct pm_qos_request *req = filp->private_data; - if (!pm_qos_req) + if (!req) return -EINVAL; - if (!pm_qos_request_active(pm_qos_req)) + if (!pm_qos_request_active(req)) return -EINVAL; - o = pm_qos_array[pm_qos_req->pm_qos_class]; + o = pm_qos_array[req->pm_qos_class]; spin_lock_irqsave(&pm_qos_lock, flags); value = pm_qos_get_value(o); spin_unlock_irqrestore(&pm_qos_lock, flags); @@ -418,7 +418,7 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos) { s32 value; - struct pm_qos_request_list *pm_qos_req; + struct pm_qos_request *req; if (count == sizeof(s32)) { if (copy_from_user(&value, buf, sizeof(s32))) @@ -449,8 +449,8 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, return -EINVAL; } - pm_qos_req = filp->private_data; - pm_qos_update_request(pm_qos_req, value); + req = filp->private_data; + pm_qos_update_request(req, value); return count; } -- cgit v1.2.3-59-g8ed1b From 4a31a33425a1eb92f6a0b9846f081842268361c8 Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Thu, 25 Aug 2011 15:35:20 +0200 Subject: PM QoS: Code reorganization Move around the PM QoS misc devices management code for better readability. Signed-off-by: Jean Pihet Acked-by: markgross Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki --- kernel/power/qos.c | 45 +++++++++++++++++++++++---------------------- 1 file changed, 23 insertions(+), 22 deletions(-) diff --git a/kernel/power/qos.c b/kernel/power/qos.c index aa52c44e6080..788c4cfe0cdb 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -188,28 +188,6 @@ static void update_target(struct pm_qos_object *o, struct plist_node *node, NULL); } -static int register_pm_qos_misc(struct pm_qos_object *qos) -{ - qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; - qos->pm_qos_power_miscdev.name = qos->name; - qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; - - return misc_register(&qos->pm_qos_power_miscdev); -} - -static int find_pm_qos_object_by_minor(int minor) -{ - int pm_qos_class; - - for (pm_qos_class = 0; - pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) { - if (minor == - pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor) - return pm_qos_class; - } - return -1; -} - /** * pm_qos_request - returns current system wide qos expectation * @pm_qos_class: identification of which qos value is requested @@ -362,6 +340,29 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) } EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); +/* User space interface to PM QoS classes via misc devices */ +static int register_pm_qos_misc(struct pm_qos_object *qos) +{ + qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; + qos->pm_qos_power_miscdev.name = qos->name; + qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops; + + return misc_register(&qos->pm_qos_power_miscdev); +} + +static int find_pm_qos_object_by_minor(int minor) +{ + int pm_qos_class; + + for (pm_qos_class = 0; + pm_qos_class < PM_QOS_NUM_CLASSES; pm_qos_class++) { + if (minor == + pm_qos_array[pm_qos_class]->pm_qos_power_miscdev.minor) + return pm_qos_class; + } + return -1; +} + static int pm_qos_power_open(struct inode *inode, struct file *filp) { long pm_qos_class; -- cgit v1.2.3-59-g8ed1b From 4e1779baaa542c83b459b0a56585e0c1a04c7782 Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Thu, 25 Aug 2011 15:35:27 +0200 Subject: PM QoS: Reorganize data structs In preparation for the per-device constratins support, re-organize the data strctures: - add a struct pm_qos_constraints which contains the constraints related data - update struct pm_qos_object contents to the PM QoS internal object data. Add a pointer to struct pm_qos_constraints - update the internal code to use the new data structs. Signed-off-by: Jean Pihet Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki --- include/linux/pm_qos.h | 19 +++++++++++ kernel/power/qos.c | 85 ++++++++++++++++++++++++-------------------------- 2 files changed, 60 insertions(+), 44 deletions(-) diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 6b0968f8bc6e..97723113ae92 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -25,6 +25,25 @@ struct pm_qos_request { int pm_qos_class; }; +enum pm_qos_type { + PM_QOS_UNITIALIZED, + PM_QOS_MAX, /* return the largest value */ + PM_QOS_MIN /* return the smallest value */ +}; + +/* + * Note: The lockless read path depends on the CPU accessing + * target_value atomically. Atomic access is only guaranteed on all CPU + * types linux supports for 32 bit quantites + */ +struct pm_qos_constraints { + struct plist_head list; + s32 target_value; /* Do not change to 64 bit */ + s32 default_value; + enum pm_qos_type type; + struct blocking_notifier_head *notifiers; +}; + #ifdef CONFIG_PM void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, s32 value); diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 788c4cfe0cdb..4a35fe50b777 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -49,58 +49,53 @@ * or pm_qos_object list and pm_qos_objects need to happen with pm_qos_lock * held, taken with _irqsave. One lock to rule them all */ -enum pm_qos_type { - PM_QOS_MAX, /* return the largest value */ - PM_QOS_MIN /* return the smallest value */ -}; - -/* - * Note: The lockless read path depends on the CPU accessing - * target_value atomically. Atomic access is only guaranteed on all CPU - * types linux supports for 32 bit quantites - */ struct pm_qos_object { - struct plist_head constraints; - struct blocking_notifier_head *notifiers; + struct pm_qos_constraints *constraints; struct miscdevice pm_qos_power_miscdev; char *name; - s32 target_value; /* Do not change to 64 bit */ - s32 default_value; - enum pm_qos_type type; }; static DEFINE_SPINLOCK(pm_qos_lock); static struct pm_qos_object null_pm_qos; + static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); -static struct pm_qos_object cpu_dma_pm_qos = { - .constraints = PLIST_HEAD_INIT(cpu_dma_pm_qos.constraints), - .notifiers = &cpu_dma_lat_notifier, - .name = "cpu_dma_latency", +static struct pm_qos_constraints cpu_dma_constraints = { + .list = PLIST_HEAD_INIT(cpu_dma_constraints.list), .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, .type = PM_QOS_MIN, + .notifiers = &cpu_dma_lat_notifier, +}; +static struct pm_qos_object cpu_dma_pm_qos = { + .constraints = &cpu_dma_constraints, }; static BLOCKING_NOTIFIER_HEAD(network_lat_notifier); -static struct pm_qos_object network_lat_pm_qos = { - .constraints = PLIST_HEAD_INIT(network_lat_pm_qos.constraints), - .notifiers = &network_lat_notifier, - .name = "network_latency", +static struct pm_qos_constraints network_lat_constraints = { + .list = PLIST_HEAD_INIT(network_lat_constraints.list), .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE, - .type = PM_QOS_MIN + .type = PM_QOS_MIN, + .notifiers = &network_lat_notifier, +}; +static struct pm_qos_object network_lat_pm_qos = { + .constraints = &network_lat_constraints, + .name = "network_latency", }; static BLOCKING_NOTIFIER_HEAD(network_throughput_notifier); -static struct pm_qos_object network_throughput_pm_qos = { - .constraints = PLIST_HEAD_INIT(network_throughput_pm_qos.constraints), - .notifiers = &network_throughput_notifier, - .name = "network_throughput", +static struct pm_qos_constraints network_tput_constraints = { + .list = PLIST_HEAD_INIT(network_tput_constraints.list), .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE, .type = PM_QOS_MAX, + .notifiers = &network_throughput_notifier, +}; +static struct pm_qos_object network_throughput_pm_qos = { + .constraints = &network_tput_constraints, + .name = "network_throughput", }; @@ -129,15 +124,15 @@ static const struct file_operations pm_qos_power_fops = { /* unlocked internal variant */ static inline int pm_qos_get_value(struct pm_qos_object *o) { - if (plist_head_empty(&o->constraints)) - return o->default_value; + if (plist_head_empty(&o->constraints->list)) + return o->constraints->default_value; - switch (o->type) { + switch (o->constraints->type) { case PM_QOS_MIN: - return plist_first(&o->constraints)->prio; + return plist_first(&o->constraints->list)->prio; case PM_QOS_MAX: - return plist_last(&o->constraints)->prio; + return plist_last(&o->constraints->list)->prio; default: /* runtime check for not using enum */ @@ -147,12 +142,12 @@ static inline int pm_qos_get_value(struct pm_qos_object *o) static inline s32 pm_qos_read_value(struct pm_qos_object *o) { - return o->target_value; + return o->constraints->target_value; } static inline void pm_qos_set_value(struct pm_qos_object *o, s32 value) { - o->target_value = value; + o->constraints->target_value = value; } static void update_target(struct pm_qos_object *o, struct plist_node *node, @@ -170,20 +165,20 @@ static void update_target(struct pm_qos_object *o, struct plist_node *node, * with new value and add, then see if the extremal * changed */ - plist_del(node, &o->constraints); + plist_del(node, &o->constraints->list); plist_node_init(node, value); - plist_add(node, &o->constraints); + plist_add(node, &o->constraints->list); } else if (del) { - plist_del(node, &o->constraints); + plist_del(node, &o->constraints->list); } else { - plist_add(node, &o->constraints); + plist_add(node, &o->constraints->list); } curr_value = pm_qos_get_value(o); pm_qos_set_value(o, curr_value); spin_unlock_irqrestore(&pm_qos_lock, flags); if (prev_value != curr_value) - blocking_notifier_call_chain(o->notifiers, + blocking_notifier_call_chain(o->constraints->notifiers, (unsigned long)curr_value, NULL); } @@ -230,7 +225,7 @@ void pm_qos_add_request(struct pm_qos_request *req, return; } if (value == PM_QOS_DEFAULT_VALUE) - new_value = o->default_value; + new_value = o->constraints->default_value; else new_value = value; plist_node_init(&req->node, new_value); @@ -266,7 +261,7 @@ void pm_qos_update_request(struct pm_qos_request *req, o = pm_qos_array[req->pm_qos_class]; if (new_value == PM_QOS_DEFAULT_VALUE) - temp = o->default_value; + temp = o->constraints->default_value; else temp = new_value; @@ -315,7 +310,8 @@ int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) int retval; retval = blocking_notifier_chain_register( - pm_qos_array[pm_qos_class]->notifiers, notifier); + pm_qos_array[pm_qos_class]->constraints->notifiers, + notifier); return retval; } @@ -334,7 +330,8 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) int retval; retval = blocking_notifier_chain_unregister( - pm_qos_array[pm_qos_class]->notifiers, notifier); + pm_qos_array[pm_qos_class]->constraints->notifiers, + notifier); return retval; } -- cgit v1.2.3-59-g8ed1b From abe98ec2d86279fe821c9051003a0abc43444f15 Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Thu, 25 Aug 2011 15:35:34 +0200 Subject: PM QoS: Generalize and export constraints management code In preparation for the per-device constratins support: - rename update_target to pm_qos_update_target - generalize and export pm_qos_update_target for usage by the upcoming per-device latency constraints framework: * operate on struct pm_qos_constraints for constraints management, * introduce an 'action' parameter for constraints add/update/remove, * the return value indicates if the aggregated constraint value has changed, - update the internal code to operate on struct pm_qos_constraints - add a NULL pointer check in the API functions Signed-off-by: Jean Pihet Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki --- include/linux/pm_qos.h | 14 ++++++ kernel/power/qos.c | 123 +++++++++++++++++++++++++++---------------------- 2 files changed, 81 insertions(+), 56 deletions(-) diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 97723113ae92..84aa15089896 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -44,7 +44,16 @@ struct pm_qos_constraints { struct blocking_notifier_head *notifiers; }; +/* Action requested to pm_qos_update_target */ +enum pm_qos_req_action { + PM_QOS_ADD_REQ, /* Add a new request */ + PM_QOS_UPDATE_REQ, /* Update an existing request */ + PM_QOS_REMOVE_REQ /* Remove an existing request */ +}; + #ifdef CONFIG_PM +int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, + enum pm_qos_req_action action, int value); void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, s32 value); void pm_qos_update_request(struct pm_qos_request *req, @@ -56,6 +65,11 @@ int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_request_active(struct pm_qos_request *req); #else +static inline int pm_qos_update_target(struct pm_qos_constraints *c, + struct plist_node *node, + enum pm_qos_req_action action, + int value) + { return 0; } static inline void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, s32 value) { return; } diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 4a35fe50b777..7c7cd181cabe 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -122,17 +122,17 @@ static const struct file_operations pm_qos_power_fops = { }; /* unlocked internal variant */ -static inline int pm_qos_get_value(struct pm_qos_object *o) +static inline int pm_qos_get_value(struct pm_qos_constraints *c) { - if (plist_head_empty(&o->constraints->list)) - return o->constraints->default_value; + if (plist_head_empty(&c->list)) + return c->default_value; - switch (o->constraints->type) { + switch (c->type) { case PM_QOS_MIN: - return plist_first(&o->constraints->list)->prio; + return plist_first(&c->list)->prio; case PM_QOS_MAX: - return plist_last(&o->constraints->list)->prio; + return plist_last(&c->list)->prio; default: /* runtime check for not using enum */ @@ -140,47 +140,73 @@ static inline int pm_qos_get_value(struct pm_qos_object *o) } } -static inline s32 pm_qos_read_value(struct pm_qos_object *o) +static inline s32 pm_qos_read_value(struct pm_qos_constraints *c) { - return o->constraints->target_value; + return c->target_value; } -static inline void pm_qos_set_value(struct pm_qos_object *o, s32 value) +static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) { - o->constraints->target_value = value; + c->target_value = value; } -static void update_target(struct pm_qos_object *o, struct plist_node *node, - int del, int value) +/** + * pm_qos_update_target - manages the constraints list and calls the notifiers + * if needed + * @c: constraints data struct + * @node: request to add to the list, to update or to remove + * @action: action to take on the constraints list + * @value: value of the request to add or update + * + * This function returns 1 if the aggregated constraint value has changed, 0 + * otherwise. + */ +int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, + enum pm_qos_req_action action, int value) { unsigned long flags; - int prev_value, curr_value; + int prev_value, curr_value, new_value; spin_lock_irqsave(&pm_qos_lock, flags); - prev_value = pm_qos_get_value(o); - /* PM_QOS_DEFAULT_VALUE is a signal that the value is unchanged */ - if (value != PM_QOS_DEFAULT_VALUE) { + prev_value = pm_qos_get_value(c); + if (value == PM_QOS_DEFAULT_VALUE) + new_value = c->default_value; + else + new_value = value; + + switch (action) { + case PM_QOS_REMOVE_REQ: + plist_del(node, &c->list); + break; + case PM_QOS_UPDATE_REQ: /* * to change the list, we atomically remove, reinit * with new value and add, then see if the extremal * changed */ - plist_del(node, &o->constraints->list); - plist_node_init(node, value); - plist_add(node, &o->constraints->list); - } else if (del) { - plist_del(node, &o->constraints->list); - } else { - plist_add(node, &o->constraints->list); + plist_del(node, &c->list); + case PM_QOS_ADD_REQ: + plist_node_init(node, new_value); + plist_add(node, &c->list); + break; + default: + /* no action */ + ; } - curr_value = pm_qos_get_value(o); - pm_qos_set_value(o, curr_value); + + curr_value = pm_qos_get_value(c); + pm_qos_set_value(c, curr_value); + spin_unlock_irqrestore(&pm_qos_lock, flags); - if (prev_value != curr_value) - blocking_notifier_call_chain(o->constraints->notifiers, + if (prev_value != curr_value) { + blocking_notifier_call_chain(c->notifiers, (unsigned long)curr_value, NULL); + return 1; + } else { + return 0; + } } /** @@ -191,7 +217,7 @@ static void update_target(struct pm_qos_object *o, struct plist_node *node, */ int pm_qos_request(int pm_qos_class) { - return pm_qos_read_value(pm_qos_array[pm_qos_class]); + return pm_qos_read_value(pm_qos_array[pm_qos_class]->constraints); } EXPORT_SYMBOL_GPL(pm_qos_request); @@ -217,20 +243,16 @@ EXPORT_SYMBOL_GPL(pm_qos_request_active); void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, s32 value) { - struct pm_qos_object *o = pm_qos_array[pm_qos_class]; - int new_value; + if (!req) /*guard against callers passing in null */ + return; if (pm_qos_request_active(req)) { WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); return; } - if (value == PM_QOS_DEFAULT_VALUE) - new_value = o->constraints->default_value; - else - new_value = value; - plist_node_init(&req->node, new_value); req->pm_qos_class = pm_qos_class; - update_target(o, &req->node, 0, PM_QOS_DEFAULT_VALUE); + pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, + &req->node, PM_QOS_ADD_REQ, value); } EXPORT_SYMBOL_GPL(pm_qos_add_request); @@ -247,9 +269,6 @@ EXPORT_SYMBOL_GPL(pm_qos_add_request); void pm_qos_update_request(struct pm_qos_request *req, s32 new_value) { - s32 temp; - struct pm_qos_object *o; - if (!req) /*guard against callers passing in null */ return; @@ -258,15 +277,10 @@ void pm_qos_update_request(struct pm_qos_request *req, return; } - o = pm_qos_array[req->pm_qos_class]; - - if (new_value == PM_QOS_DEFAULT_VALUE) - temp = o->constraints->default_value; - else - temp = new_value; - - if (temp != req->node.prio) - update_target(o, &req->node, 0, temp); + if (new_value != req->node.prio) + pm_qos_update_target( + pm_qos_array[req->pm_qos_class]->constraints, + &req->node, PM_QOS_UPDATE_REQ, new_value); } EXPORT_SYMBOL_GPL(pm_qos_update_request); @@ -280,9 +294,7 @@ EXPORT_SYMBOL_GPL(pm_qos_update_request); */ void pm_qos_remove_request(struct pm_qos_request *req) { - struct pm_qos_object *o; - - if (req == NULL) + if (!req) /*guard against callers passing in null */ return; /* silent return to keep pcm code cleaner */ @@ -291,8 +303,9 @@ void pm_qos_remove_request(struct pm_qos_request *req) return; } - o = pm_qos_array[req->pm_qos_class]; - update_target(o, &req->node, 1, PM_QOS_DEFAULT_VALUE); + pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, + &req->node, PM_QOS_REMOVE_REQ, + PM_QOS_DEFAULT_VALUE); memset(req, 0, sizeof(*req)); } EXPORT_SYMBOL_GPL(pm_qos_remove_request); @@ -396,7 +409,6 @@ static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, { s32 value; unsigned long flags; - struct pm_qos_object *o; struct pm_qos_request *req = filp->private_data; if (!req) @@ -404,9 +416,8 @@ static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, if (!pm_qos_request_active(req)) return -EINVAL; - o = pm_qos_array[req->pm_qos_class]; spin_lock_irqsave(&pm_qos_lock, flags); - value = pm_qos_get_value(o); + value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints); spin_unlock_irqrestore(&pm_qos_lock, flags); return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); -- cgit v1.2.3-59-g8ed1b From 91ff4cb803df6de9114351b9f2f0f39f397ee03e Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Thu, 25 Aug 2011 15:35:41 +0200 Subject: PM QoS: Implement per-device PM QoS constraints Implement the per-device PM QoS constraints by creating a device PM QoS API, which calls the PM QoS constraints management core code. The per-device latency constraints data strctures are stored in the device dev_pm_info struct. The device PM code calls the init and destroy of the per-device constraints data struct in order to support the dynamic insertion and removal of the devices in the system. To minimize the data usage by the per-device constraints, the data struct is only allocated at the first call to dev_pm_qos_add_request. The data is later free'd when the device is removed from the system. A global mutex protects the constraints users from the data being allocated and free'd. Signed-off-by: Jean Pihet Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki --- drivers/base/power/Makefile | 4 +- drivers/base/power/main.c | 3 + drivers/base/power/qos.c | 338 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/pm.h | 9 ++ include/linux/pm_qos.h | 42 ++++++ 5 files changed, 394 insertions(+), 2 deletions(-) create mode 100644 drivers/base/power/qos.c diff --git a/drivers/base/power/Makefile b/drivers/base/power/Makefile index 6488ce12f586..81676dd17900 100644 --- a/drivers/base/power/Makefile +++ b/drivers/base/power/Makefile @@ -1,4 +1,4 @@ -obj-$(CONFIG_PM) += sysfs.o generic_ops.o common.o +obj-$(CONFIG_PM) += sysfs.o generic_ops.o common.o qos.o obj-$(CONFIG_PM_SLEEP) += main.o wakeup.o obj-$(CONFIG_PM_RUNTIME) += runtime.o obj-$(CONFIG_PM_TRACE_RTC) += trace.o @@ -6,4 +6,4 @@ obj-$(CONFIG_PM_OPP) += opp.o obj-$(CONFIG_PM_GENERIC_DOMAINS) += domain.o obj-$(CONFIG_HAVE_CLK) += clock_ops.o -ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG \ No newline at end of file +ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index a85459126bc6..956443f86254 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -97,6 +98,7 @@ void device_pm_add(struct device *dev) dev_name(dev->parent)); list_add_tail(&dev->power.entry, &dpm_list); mutex_unlock(&dpm_list_mtx); + dev_pm_qos_constraints_init(dev); } /** @@ -107,6 +109,7 @@ void device_pm_remove(struct device *dev) { pr_debug("PM: Removing info for %s:%s\n", dev->bus ? dev->bus->name : "No Bus", dev_name(dev)); + dev_pm_qos_constraints_destroy(dev); complete_all(&dev->power.completion); mutex_lock(&dpm_list_mtx); list_del_init(&dev->power.entry); diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c new file mode 100644 index 000000000000..cc4c541398aa --- /dev/null +++ b/drivers/base/power/qos.c @@ -0,0 +1,338 @@ +/* + * Devices PM QoS constraints management + * + * Copyright (C) 2011 Texas Instruments, Inc. + * + * 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. + * + * + * This module exposes the interface to kernel space for specifying + * per-device PM QoS dependencies. It provides infrastructure for registration + * of: + * + * Dependents on a QoS value : register requests + * Watchers of QoS value : get notified when target QoS value changes + * + * This QoS design is best effort based. Dependents register their QoS needs. + * Watchers register to keep track of the current QoS needs of the system. + * + * Note about the per-device constraint data struct allocation: + * . The per-device constraints data struct ptr is tored into the device + * dev_pm_info. + * . To minimize the data usage by the per-device constraints, the data struct + * is only allocated at the first call to dev_pm_qos_add_request. + * . The data is later free'd when the device is removed from the system. + * . The constraints_state variable from dev_pm_info tracks the data struct + * allocation state: + * DEV_PM_QOS_NO_DEVICE: No device present or device removed, no data + * allocated, + * DEV_PM_QOS_DEVICE_PRESENT: Device present, data not allocated and will be + * allocated at the first call to dev_pm_qos_add_request, + * DEV_PM_QOS_ALLOCATED: Device present, data allocated. The per-device + * PM QoS constraints framework is operational and constraints can be + * added, updated or removed using the dev_pm_qos_* API. + * . A global mutex protects the constraints users from the data being + * allocated and free'd. + */ + +#include +#include +#include +#include +#include + + +static DEFINE_MUTEX(dev_pm_qos_mtx); + +/* + * dev_pm_qos_constraints_allocate + * @dev: device to allocate data for + * + * Called at the first call to add_request, for constraint data allocation + * Must be called with the dev_pm_qos_mtx mutex held + */ +static int dev_pm_qos_constraints_allocate(struct device *dev) +{ + struct pm_qos_constraints *c; + struct blocking_notifier_head *n; + + c = kzalloc(sizeof(*c), GFP_KERNEL); + if (!c) + return -ENOMEM; + + n = kzalloc(sizeof(*n), GFP_KERNEL); + if (!n) { + kfree(c); + return -ENOMEM; + } + BLOCKING_INIT_NOTIFIER_HEAD(n); + + dev->power.constraints = c; + plist_head_init(&dev->power.constraints->list); + dev->power.constraints->target_value = PM_QOS_DEV_LAT_DEFAULT_VALUE; + dev->power.constraints->default_value = PM_QOS_DEV_LAT_DEFAULT_VALUE; + dev->power.constraints->type = PM_QOS_MIN; + dev->power.constraints->notifiers = n; + dev->power.constraints_state = DEV_PM_QOS_ALLOCATED; + + return 0; +} + +/** + * dev_pm_qos_constraints_init + * @dev: target device + * + * Called from the device PM subsystem at device insertion + */ +void dev_pm_qos_constraints_init(struct device *dev) +{ + mutex_lock(&dev_pm_qos_mtx); + dev->power.constraints_state = DEV_PM_QOS_DEVICE_PRESENT; + mutex_unlock(&dev_pm_qos_mtx); +} + +/** + * dev_pm_qos_constraints_destroy + * @dev: target device + * + * Called from the device PM subsystem at device removal + */ +void dev_pm_qos_constraints_destroy(struct device *dev) +{ + struct dev_pm_qos_request *req, *tmp; + + mutex_lock(&dev_pm_qos_mtx); + + if (dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) { + /* Flush the constraints list for the device */ + plist_for_each_entry_safe(req, tmp, + &dev->power.constraints->list, + node) { + /* + * Update constraints list and call the per-device + * callbacks if needed + */ + pm_qos_update_target(req->dev->power.constraints, + &req->node, PM_QOS_REMOVE_REQ, + PM_QOS_DEFAULT_VALUE); + memset(req, 0, sizeof(*req)); + } + + kfree(dev->power.constraints->notifiers); + kfree(dev->power.constraints); + dev->power.constraints = NULL; + } + dev->power.constraints_state = DEV_PM_QOS_NO_DEVICE; + + mutex_unlock(&dev_pm_qos_mtx); +} + +/** + * dev_pm_qos_add_request - inserts new qos request into the list + * @dev: target device for the constraint + * @req: pointer to a preallocated handle + * @value: defines the qos request + * + * This function inserts a new entry in the device constraints list of + * requested qos performance characteristics. It recomputes the aggregate + * QoS expectations of parameters and initializes the dev_pm_qos_request + * handle. Caller needs to save this handle for later use in updates and + * removal. + * + * Returns 1 if the aggregated constraint value has changed, + * 0 if the aggregated constraint value has not changed, + * -EINVAL in case of wrong parameters, -ENODEV if the device has been + * removed from the system + */ +int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, + s32 value) +{ + int ret = 0; + + if (!dev || !req) /*guard against callers passing in null */ + return -EINVAL; + + if (dev_pm_qos_request_active(req)) { + WARN(1, KERN_ERR "dev_pm_qos_add_request() called for already " + "added request\n"); + return -EINVAL; + } + + mutex_lock(&dev_pm_qos_mtx); + req->dev = dev; + + /* Return if the device has been removed */ + if (req->dev->power.constraints_state == DEV_PM_QOS_NO_DEVICE) { + ret = -ENODEV; + goto out; + } + + /* + * Allocate the constraints data on the first call to add_request, + * i.e. only if the data is not already allocated and if the device has + * not been removed + */ + if (dev->power.constraints_state == DEV_PM_QOS_DEVICE_PRESENT) + ret = dev_pm_qos_constraints_allocate(dev); + + if (!ret) + ret = pm_qos_update_target(dev->power.constraints, &req->node, + PM_QOS_ADD_REQ, value); + +out: + mutex_unlock(&dev_pm_qos_mtx); + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_add_request); + +/** + * dev_pm_qos_update_request - modifies an existing qos request + * @req : handle to list element holding a dev_pm_qos request to use + * @new_value: defines the qos request + * + * Updates an existing dev PM qos request along with updating the + * target value. + * + * Attempts are made to make this code callable on hot code paths. + * + * Returns 1 if the aggregated constraint value has changed, + * 0 if the aggregated constraint value has not changed, + * -EINVAL in case of wrong parameters, -ENODEV if the device has been + * removed from the system + */ +int dev_pm_qos_update_request(struct dev_pm_qos_request *req, + s32 new_value) +{ + int ret = 0; + + if (!req) /*guard against callers passing in null */ + return -EINVAL; + + if (!dev_pm_qos_request_active(req)) { + WARN(1, KERN_ERR "dev_pm_qos_update_request() called for " + "unknown object\n"); + return -EINVAL; + } + + mutex_lock(&dev_pm_qos_mtx); + + if (req->dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) { + if (new_value != req->node.prio) + ret = pm_qos_update_target(req->dev->power.constraints, + &req->node, + PM_QOS_UPDATE_REQ, + new_value); + } else { + /* Return if the device has been removed */ + ret = -ENODEV; + } + + mutex_unlock(&dev_pm_qos_mtx); + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_update_request); + +/** + * dev_pm_qos_remove_request - modifies an existing qos request + * @req: handle to request list element + * + * Will remove pm qos request from the list of constraints and + * recompute the current target value. Call this on slow code paths. + * + * Returns 1 if the aggregated constraint value has changed, + * 0 if the aggregated constraint value has not changed, + * -EINVAL in case of wrong parameters, -ENODEV if the device has been + * removed from the system + */ +int dev_pm_qos_remove_request(struct dev_pm_qos_request *req) +{ + int ret = 0; + + if (!req) /*guard against callers passing in null */ + return -EINVAL; + + if (!dev_pm_qos_request_active(req)) { + WARN(1, KERN_ERR "dev_pm_qos_remove_request() called for " + "unknown object\n"); + return -EINVAL; + } + + mutex_lock(&dev_pm_qos_mtx); + + if (req->dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) { + ret = pm_qos_update_target(req->dev->power.constraints, + &req->node, PM_QOS_REMOVE_REQ, + PM_QOS_DEFAULT_VALUE); + memset(req, 0, sizeof(*req)); + } else { + /* Return if the device has been removed */ + ret = -ENODEV; + } + + mutex_unlock(&dev_pm_qos_mtx); + return ret; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request); + +/** + * dev_pm_qos_add_notifier - sets notification entry for changes to target value + * of per-device PM QoS constraints + * + * @dev: target device for the constraint + * @notifier: notifier block managed by caller. + * + * Will register the notifier into a notification chain that gets called + * upon changes to the target value for the device. + */ +int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier) +{ + int retval = 0; + + mutex_lock(&dev_pm_qos_mtx); + + /* Silently return if the device has been removed */ + if (dev->power.constraints_state != DEV_PM_QOS_ALLOCATED) + goto out; + + retval = blocking_notifier_chain_register( + dev->power.constraints->notifiers, + notifier); + +out: + mutex_unlock(&dev_pm_qos_mtx); + return retval; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier); + +/** + * dev_pm_qos_remove_notifier - deletes notification for changes to target value + * of per-device PM QoS constraints + * + * @dev: target device for the constraint + * @notifier: notifier block to be removed. + * + * Will remove the notifier from the notification chain that gets called + * upon changes to the target value. + */ +int dev_pm_qos_remove_notifier(struct device *dev, + struct notifier_block *notifier) +{ + int retval = 0; + + mutex_lock(&dev_pm_qos_mtx); + + /* Silently return if the device has been removed */ + if (dev->power.constraints_state != DEV_PM_QOS_ALLOCATED) + goto out; + + retval = blocking_notifier_chain_unregister( + dev->power.constraints->notifiers, + notifier); + +out: + mutex_unlock(&dev_pm_qos_mtx); + return retval; +} +EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier); diff --git a/include/linux/pm.h b/include/linux/pm.h index ed10f24d5259..d78187e9ca99 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -419,6 +419,13 @@ enum rpm_request { RPM_REQ_RESUME, }; +/* Per-device PM QoS constraints data struct state */ +enum dev_pm_qos_state { + DEV_PM_QOS_NO_DEVICE, /* No device present */ + DEV_PM_QOS_DEVICE_PRESENT, /* Device present, data not allocated */ + DEV_PM_QOS_ALLOCATED, /* Device present, data allocated */ +}; + struct wakeup_source; struct pm_domain_data { @@ -480,6 +487,8 @@ struct dev_pm_info { unsigned long accounting_timestamp; #endif struct pm_subsys_data *subsys_data; /* Owned by the subsystem. */ + struct pm_qos_constraints *constraints; + enum dev_pm_qos_state constraints_state; }; extern void update_pm_runtime_accounting(struct device *dev); diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 84aa15089896..f75f74dd9b90 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -19,12 +19,18 @@ #define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) #define PM_QOS_NETWORK_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) #define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0 +#define PM_QOS_DEV_LAT_DEFAULT_VALUE 0 struct pm_qos_request { struct plist_node node; int pm_qos_class; }; +struct dev_pm_qos_request { + struct plist_node node; + struct device *dev; +}; + enum pm_qos_type { PM_QOS_UNITIALIZED, PM_QOS_MAX, /* return the largest value */ @@ -51,6 +57,11 @@ enum pm_qos_req_action { PM_QOS_REMOVE_REQ /* Remove an existing request */ }; +static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req) +{ + return req->dev != 0; +} + #ifdef CONFIG_PM int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, enum pm_qos_req_action action, int value); @@ -64,6 +75,17 @@ int pm_qos_request(int pm_qos_class); int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_request_active(struct pm_qos_request *req); + +int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, + s32 value); +int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value); +int dev_pm_qos_remove_request(struct dev_pm_qos_request *req); +int dev_pm_qos_add_notifier(struct device *dev, + struct notifier_block *notifier); +int dev_pm_qos_remove_notifier(struct device *dev, + struct notifier_block *notifier); +void dev_pm_qos_constraints_init(struct device *dev); +void dev_pm_qos_constraints_destroy(struct device *dev); #else static inline int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, @@ -89,6 +111,26 @@ static inline int pm_qos_remove_notifier(int pm_qos_class, { return 0; } static inline int pm_qos_request_active(struct pm_qos_request *req) { return 0; } + +static inline int dev_pm_qos_add_request(struct device *dev, + struct dev_pm_qos_request *req, + s32 value) + { return 0; } +static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req, + s32 new_value) + { return 0; } +static inline int dev_pm_qos_remove_request(struct dev_pm_qos_request *req) + { return 0; } +static inline int dev_pm_qos_add_notifier(struct device *dev, + struct notifier_block *notifier) + { return 0; } +static inline int dev_pm_qos_remove_notifier(struct device *dev, + struct notifier_block *notifier) + { return 0; } +static inline void dev_pm_qos_constraints_init(struct device *dev) + { return; } +static inline void dev_pm_qos_constraints_destroy(struct device *dev) + { return; } #endif #endif -- cgit v1.2.3-59-g8ed1b From b66213cdb002b08b29603d488c451dfe25e2ca20 Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Thu, 25 Aug 2011 15:35:47 +0200 Subject: PM QoS: Add global notification mechanism for device constraints Add a global notification chain that gets called upon changes to the aggregated constraint value for any device. The notification callbacks are passing the full constraint request data in order for the callees to have access to it. The current use is for the platform low-level code to access the target device of the constraint. Signed-off-by: Jean Pihet Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki --- drivers/base/power/qos.c | 89 ++++++++++++++++++++++++++++++++++++++++-------- include/linux/pm_qos.h | 11 ++++++ kernel/power/qos.c | 2 +- 3 files changed, 87 insertions(+), 15 deletions(-) diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c index cc4c541398aa..8d0b81151c14 100644 --- a/drivers/base/power/qos.c +++ b/drivers/base/power/qos.c @@ -17,6 +17,12 @@ * * This QoS design is best effort based. Dependents register their QoS needs. * Watchers register to keep track of the current QoS needs of the system. + * Watchers can register different types of notification callbacks: + * . a per-device notification callback using the dev_pm_qos_*_notifier API. + * The notification chain data is stored in the per-device constraint + * data struct. + * . a system-wide notification callback using the dev_pm_qos_*_global_notifier + * API. The notification chain data is stored in a static variable. * * Note about the per-device constraint data struct allocation: * . The per-device constraints data struct ptr is tored into the device @@ -45,6 +51,36 @@ static DEFINE_MUTEX(dev_pm_qos_mtx); +static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers); + +/* + * apply_constraint + * @req: constraint request to apply + * @action: action to perform add/update/remove, of type enum pm_qos_req_action + * @value: defines the qos request + * + * Internal function to update the constraints list using the PM QoS core + * code and if needed call the per-device and the global notification + * callbacks + */ +static int apply_constraint(struct dev_pm_qos_request *req, + enum pm_qos_req_action action, int value) +{ + int ret, curr_value; + + ret = pm_qos_update_target(req->dev->power.constraints, + &req->node, action, value); + + if (ret) { + /* Call the global callbacks if needed */ + curr_value = pm_qos_read_value(req->dev->power.constraints); + blocking_notifier_call_chain(&dev_pm_notifiers, + (unsigned long)curr_value, + req); + } + + return ret; +} /* * dev_pm_qos_constraints_allocate @@ -111,12 +147,11 @@ void dev_pm_qos_constraints_destroy(struct device *dev) &dev->power.constraints->list, node) { /* - * Update constraints list and call the per-device + * Update constraints list and call the notification * callbacks if needed */ - pm_qos_update_target(req->dev->power.constraints, - &req->node, PM_QOS_REMOVE_REQ, - PM_QOS_DEFAULT_VALUE); + apply_constraint(req, PM_QOS_REMOVE_REQ, + PM_QOS_DEFAULT_VALUE); memset(req, 0, sizeof(*req)); } @@ -147,7 +182,7 @@ void dev_pm_qos_constraints_destroy(struct device *dev) * removed from the system */ int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, - s32 value) + s32 value) { int ret = 0; @@ -178,8 +213,7 @@ int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, ret = dev_pm_qos_constraints_allocate(dev); if (!ret) - ret = pm_qos_update_target(dev->power.constraints, &req->node, - PM_QOS_ADD_REQ, value); + ret = apply_constraint(req, PM_QOS_ADD_REQ, value); out: mutex_unlock(&dev_pm_qos_mtx); @@ -220,10 +254,8 @@ int dev_pm_qos_update_request(struct dev_pm_qos_request *req, if (req->dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) { if (new_value != req->node.prio) - ret = pm_qos_update_target(req->dev->power.constraints, - &req->node, - PM_QOS_UPDATE_REQ, - new_value); + ret = apply_constraint(req, PM_QOS_UPDATE_REQ, + new_value); } else { /* Return if the device has been removed */ ret = -ENODEV; @@ -262,9 +294,8 @@ int dev_pm_qos_remove_request(struct dev_pm_qos_request *req) mutex_lock(&dev_pm_qos_mtx); if (req->dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) { - ret = pm_qos_update_target(req->dev->power.constraints, - &req->node, PM_QOS_REMOVE_REQ, - PM_QOS_DEFAULT_VALUE); + ret = apply_constraint(req, PM_QOS_REMOVE_REQ, + PM_QOS_DEFAULT_VALUE); memset(req, 0, sizeof(*req)); } else { /* Return if the device has been removed */ @@ -336,3 +367,33 @@ out: return retval; } EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier); + +/** + * dev_pm_qos_add_global_notifier - sets notification entry for changes to + * target value of the PM QoS constraints for any device + * + * @notifier: notifier block managed by caller. + * + * Will register the notifier into a notification chain that gets called + * upon changes to the target value for any device. + */ +int dev_pm_qos_add_global_notifier(struct notifier_block *notifier) +{ + return blocking_notifier_chain_register(&dev_pm_notifiers, notifier); +} +EXPORT_SYMBOL_GPL(dev_pm_qos_add_global_notifier); + +/** + * dev_pm_qos_remove_global_notifier - deletes notification for changes to + * target value of PM QoS constraints for any device + * + * @notifier: notifier block to be removed. + * + * Will remove the notifier from the notification chain that gets called + * upon changes to the target value for any device. + */ +int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier) +{ + return blocking_notifier_chain_unregister(&dev_pm_notifiers, notifier); +} +EXPORT_SYMBOL_GPL(dev_pm_qos_remove_global_notifier); diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index f75f74dd9b90..ca7bd3f98cb4 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -75,6 +75,7 @@ int pm_qos_request(int pm_qos_class); int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_request_active(struct pm_qos_request *req); +s32 pm_qos_read_value(struct pm_qos_constraints *c); int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, s32 value); @@ -84,6 +85,8 @@ int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier); int dev_pm_qos_remove_notifier(struct device *dev, struct notifier_block *notifier); +int dev_pm_qos_add_global_notifier(struct notifier_block *notifier); +int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier); void dev_pm_qos_constraints_init(struct device *dev); void dev_pm_qos_constraints_destroy(struct device *dev); #else @@ -111,6 +114,8 @@ static inline int pm_qos_remove_notifier(int pm_qos_class, { return 0; } static inline int pm_qos_request_active(struct pm_qos_request *req) { return 0; } +static inline s32 pm_qos_read_value(struct pm_qos_constraints *c) + { return 0; } static inline int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, @@ -127,6 +132,12 @@ static inline int dev_pm_qos_add_notifier(struct device *dev, static inline int dev_pm_qos_remove_notifier(struct device *dev, struct notifier_block *notifier) { return 0; } +static inline int dev_pm_qos_add_global_notifier( + struct notifier_block *notifier) + { return 0; } +static inline int dev_pm_qos_remove_global_notifier( + struct notifier_block *notifier) + { return 0; } static inline void dev_pm_qos_constraints_init(struct device *dev) { return; } static inline void dev_pm_qos_constraints_destroy(struct device *dev) diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 7c7cd181cabe..1c1797dd1d1d 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -140,7 +140,7 @@ static inline int pm_qos_get_value(struct pm_qos_constraints *c) } } -static inline s32 pm_qos_read_value(struct pm_qos_constraints *c) +s32 pm_qos_read_value(struct pm_qos_constraints *c) { return c->target_value; } -- cgit v1.2.3-59-g8ed1b From 1a9a91525d806f2b3bd8b57b963755a96fd36ce2 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 29 Sep 2011 22:29:44 +0200 Subject: PM / QoS: Add function dev_pm_qos_read_value() (v3) To read the current PM QoS value for a given device we need to make sure that the device's power.constraints object won't be removed while we're doing that. For this reason, put the operation under dev->power.lock and acquire the lock around the initialization and removal of power.constraints. Moreover, since we're using the value of power.constraints to determine whether or not the object is present, the power.constraints_state field isn't necessary any more and may be removed. However, dev_pm_qos_add_request() needs to check if the device is being removed from the system before allocating a new PM QoS constraints object for it, so make it use the power.power_state field of struct device for this purpose. Signed-off-by: Rafael J. Wysocki --- drivers/base/power/main.c | 6 +- drivers/base/power/power.h | 10 ++- drivers/base/power/qos.c | 160 +++++++++++++++++++++++++-------------------- include/linux/pm.h | 10 +-- include/linux/pm_qos.h | 12 +++- 5 files changed, 114 insertions(+), 84 deletions(-) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 956443f86254..c6291ab725a3 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -22,7 +22,6 @@ #include #include #include -#include #include #include #include @@ -66,6 +65,7 @@ void device_pm_init(struct device *dev) spin_lock_init(&dev->power.lock); pm_runtime_init(dev); INIT_LIST_HEAD(&dev->power.entry); + dev->power.power_state = PMSG_INVALID; } /** @@ -97,8 +97,8 @@ void device_pm_add(struct device *dev) dev_warn(dev, "parent %s should not be sleeping\n", dev_name(dev->parent)); list_add_tail(&dev->power.entry, &dpm_list); - mutex_unlock(&dpm_list_mtx); dev_pm_qos_constraints_init(dev); + mutex_unlock(&dpm_list_mtx); } /** @@ -109,9 +109,9 @@ void device_pm_remove(struct device *dev) { pr_debug("PM: Removing info for %s:%s\n", dev->bus ? dev->bus->name : "No Bus", dev_name(dev)); - dev_pm_qos_constraints_destroy(dev); complete_all(&dev->power.completion); mutex_lock(&dpm_list_mtx); + dev_pm_qos_constraints_destroy(dev); list_del_init(&dev->power.entry); mutex_unlock(&dpm_list_mtx); device_wakeup_disable(dev); diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index f2a25f18fde7..9bf62323aaf3 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -1,3 +1,5 @@ +#include + #ifdef CONFIG_PM_RUNTIME extern void pm_runtime_init(struct device *dev); @@ -35,15 +37,21 @@ extern void device_pm_move_last(struct device *); static inline void device_pm_init(struct device *dev) { spin_lock_init(&dev->power.lock); + dev->power.power_state = PMSG_INVALID; pm_runtime_init(dev); } +static inline void device_pm_add(struct device *dev) +{ + dev_pm_qos_constraints_init(dev); +} + static inline void device_pm_remove(struct device *dev) { + dev_pm_qos_constraints_destroy(dev); pm_runtime_remove(dev); } -static inline void device_pm_add(struct device *dev) {} static inline void device_pm_move_before(struct device *deva, struct device *devb) {} static inline void device_pm_move_after(struct device *deva, diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c index 8d0b81151c14..91e061417382 100644 --- a/drivers/base/power/qos.c +++ b/drivers/base/power/qos.c @@ -30,15 +30,6 @@ * . To minimize the data usage by the per-device constraints, the data struct * is only allocated at the first call to dev_pm_qos_add_request. * . The data is later free'd when the device is removed from the system. - * . The constraints_state variable from dev_pm_info tracks the data struct - * allocation state: - * DEV_PM_QOS_NO_DEVICE: No device present or device removed, no data - * allocated, - * DEV_PM_QOS_DEVICE_PRESENT: Device present, data not allocated and will be - * allocated at the first call to dev_pm_qos_add_request, - * DEV_PM_QOS_ALLOCATED: Device present, data allocated. The per-device - * PM QoS constraints framework is operational and constraints can be - * added, updated or removed using the dev_pm_qos_* API. * . A global mutex protects the constraints users from the data being * allocated and free'd. */ @@ -51,8 +42,30 @@ static DEFINE_MUTEX(dev_pm_qos_mtx); + static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers); +/** + * dev_pm_qos_read_value - Get PM QoS constraint for a given device. + * @dev: Device to get the PM QoS constraint value for. + */ +s32 dev_pm_qos_read_value(struct device *dev) +{ + struct pm_qos_constraints *c; + unsigned long flags; + s32 ret = 0; + + spin_lock_irqsave(&dev->power.lock, flags); + + c = dev->power.constraints; + if (c) + ret = pm_qos_read_value(c); + + spin_unlock_irqrestore(&dev->power.lock, flags); + + return ret; +} + /* * apply_constraint * @req: constraint request to apply @@ -105,27 +118,31 @@ static int dev_pm_qos_constraints_allocate(struct device *dev) } BLOCKING_INIT_NOTIFIER_HEAD(n); + plist_head_init(&c->list); + c->target_value = PM_QOS_DEV_LAT_DEFAULT_VALUE; + c->default_value = PM_QOS_DEV_LAT_DEFAULT_VALUE; + c->type = PM_QOS_MIN; + c->notifiers = n; + + spin_lock_irq(&dev->power.lock); dev->power.constraints = c; - plist_head_init(&dev->power.constraints->list); - dev->power.constraints->target_value = PM_QOS_DEV_LAT_DEFAULT_VALUE; - dev->power.constraints->default_value = PM_QOS_DEV_LAT_DEFAULT_VALUE; - dev->power.constraints->type = PM_QOS_MIN; - dev->power.constraints->notifiers = n; - dev->power.constraints_state = DEV_PM_QOS_ALLOCATED; + spin_unlock_irq(&dev->power.lock); return 0; } /** - * dev_pm_qos_constraints_init + * dev_pm_qos_constraints_init - Initalize device's PM QoS constraints pointer. * @dev: target device * - * Called from the device PM subsystem at device insertion + * Called from the device PM subsystem during device insertion under + * device_pm_lock(). */ void dev_pm_qos_constraints_init(struct device *dev) { mutex_lock(&dev_pm_qos_mtx); - dev->power.constraints_state = DEV_PM_QOS_DEVICE_PRESENT; + dev->power.constraints = NULL; + dev->power.power_state = PMSG_ON; mutex_unlock(&dev_pm_qos_mtx); } @@ -133,34 +150,38 @@ void dev_pm_qos_constraints_init(struct device *dev) * dev_pm_qos_constraints_destroy * @dev: target device * - * Called from the device PM subsystem at device removal + * Called from the device PM subsystem on device removal under device_pm_lock(). */ void dev_pm_qos_constraints_destroy(struct device *dev) { struct dev_pm_qos_request *req, *tmp; + struct pm_qos_constraints *c; mutex_lock(&dev_pm_qos_mtx); - if (dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) { - /* Flush the constraints list for the device */ - plist_for_each_entry_safe(req, tmp, - &dev->power.constraints->list, - node) { - /* - * Update constraints list and call the notification - * callbacks if needed - */ - apply_constraint(req, PM_QOS_REMOVE_REQ, - PM_QOS_DEFAULT_VALUE); - memset(req, 0, sizeof(*req)); - } + dev->power.power_state = PMSG_INVALID; + c = dev->power.constraints; + if (!c) + goto out; - kfree(dev->power.constraints->notifiers); - kfree(dev->power.constraints); - dev->power.constraints = NULL; + /* Flush the constraints list for the device */ + plist_for_each_entry_safe(req, tmp, &c->list, node) { + /* + * Update constraints list and call the notification + * callbacks if needed + */ + apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); + memset(req, 0, sizeof(*req)); } - dev->power.constraints_state = DEV_PM_QOS_NO_DEVICE; + spin_lock_irq(&dev->power.lock); + dev->power.constraints = NULL; + spin_unlock_irq(&dev->power.lock); + + kfree(c->notifiers); + kfree(c); + + out: mutex_unlock(&dev_pm_qos_mtx); } @@ -178,8 +199,9 @@ void dev_pm_qos_constraints_destroy(struct device *dev) * * Returns 1 if the aggregated constraint value has changed, * 0 if the aggregated constraint value has not changed, - * -EINVAL in case of wrong parameters, -ENODEV if the device has been - * removed from the system + * -EINVAL in case of wrong parameters, -ENOMEM if there's not enough memory + * to allocate for data structures, -ENODEV if the device has just been removed + * from the system. */ int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, s32 value) @@ -195,28 +217,32 @@ int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, return -EINVAL; } - mutex_lock(&dev_pm_qos_mtx); req->dev = dev; - /* Return if the device has been removed */ - if (req->dev->power.constraints_state == DEV_PM_QOS_NO_DEVICE) { - ret = -ENODEV; - goto out; - } + mutex_lock(&dev_pm_qos_mtx); - /* - * Allocate the constraints data on the first call to add_request, - * i.e. only if the data is not already allocated and if the device has - * not been removed - */ - if (dev->power.constraints_state == DEV_PM_QOS_DEVICE_PRESENT) - ret = dev_pm_qos_constraints_allocate(dev); + if (!dev->power.constraints) { + if (dev->power.power_state.event == PM_EVENT_INVALID) { + /* The device has been removed from the system. */ + req->dev = NULL; + ret = -ENODEV; + goto out; + } else { + /* + * Allocate the constraints data on the first call to + * add_request, i.e. only if the data is not already + * allocated and if the device has not been removed. + */ + ret = dev_pm_qos_constraints_allocate(dev); + } + } if (!ret) ret = apply_constraint(req, PM_QOS_ADD_REQ, value); -out: + out: mutex_unlock(&dev_pm_qos_mtx); + return ret; } EXPORT_SYMBOL_GPL(dev_pm_qos_add_request); @@ -252,7 +278,7 @@ int dev_pm_qos_update_request(struct dev_pm_qos_request *req, mutex_lock(&dev_pm_qos_mtx); - if (req->dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) { + if (req->dev->power.constraints) { if (new_value != req->node.prio) ret = apply_constraint(req, PM_QOS_UPDATE_REQ, new_value); @@ -293,7 +319,7 @@ int dev_pm_qos_remove_request(struct dev_pm_qos_request *req) mutex_lock(&dev_pm_qos_mtx); - if (req->dev->power.constraints_state == DEV_PM_QOS_ALLOCATED) { + if (req->dev->power.constraints) { ret = apply_constraint(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); memset(req, 0, sizeof(*req)); @@ -323,15 +349,12 @@ int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier) mutex_lock(&dev_pm_qos_mtx); - /* Silently return if the device has been removed */ - if (dev->power.constraints_state != DEV_PM_QOS_ALLOCATED) - goto out; - - retval = blocking_notifier_chain_register( - dev->power.constraints->notifiers, - notifier); + /* Silently return if the constraints object is not present. */ + if (dev->power.constraints) + retval = blocking_notifier_chain_register( + dev->power.constraints->notifiers, + notifier); -out: mutex_unlock(&dev_pm_qos_mtx); return retval; } @@ -354,15 +377,12 @@ int dev_pm_qos_remove_notifier(struct device *dev, mutex_lock(&dev_pm_qos_mtx); - /* Silently return if the device has been removed */ - if (dev->power.constraints_state != DEV_PM_QOS_ALLOCATED) - goto out; - - retval = blocking_notifier_chain_unregister( - dev->power.constraints->notifiers, - notifier); + /* Silently return if the constraints object is not present. */ + if (dev->power.constraints) + retval = blocking_notifier_chain_unregister( + dev->power.constraints->notifiers, + notifier); -out: mutex_unlock(&dev_pm_qos_mtx); return retval; } diff --git a/include/linux/pm.h b/include/linux/pm.h index d78187e9ca99..62a876ec4d4e 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -326,6 +326,7 @@ extern struct dev_pm_ops generic_subsys_pm_ops; * requested by a driver. */ +#define PM_EVENT_INVALID (-1) #define PM_EVENT_ON 0x0000 #define PM_EVENT_FREEZE 0x0001 #define PM_EVENT_SUSPEND 0x0002 @@ -346,6 +347,7 @@ extern struct dev_pm_ops generic_subsys_pm_ops; #define PM_EVENT_AUTO_SUSPEND (PM_EVENT_AUTO | PM_EVENT_SUSPEND) #define PM_EVENT_AUTO_RESUME (PM_EVENT_AUTO | PM_EVENT_RESUME) +#define PMSG_INVALID ((struct pm_message){ .event = PM_EVENT_INVALID, }) #define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, }) #define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, }) #define PMSG_QUIESCE ((struct pm_message){ .event = PM_EVENT_QUIESCE, }) @@ -419,13 +421,6 @@ enum rpm_request { RPM_REQ_RESUME, }; -/* Per-device PM QoS constraints data struct state */ -enum dev_pm_qos_state { - DEV_PM_QOS_NO_DEVICE, /* No device present */ - DEV_PM_QOS_DEVICE_PRESENT, /* Device present, data not allocated */ - DEV_PM_QOS_ALLOCATED, /* Device present, data allocated */ -}; - struct wakeup_source; struct pm_domain_data { @@ -488,7 +483,6 @@ struct dev_pm_info { #endif struct pm_subsys_data *subsys_data; /* Owned by the subsystem. */ struct pm_qos_constraints *constraints; - enum dev_pm_qos_state constraints_state; }; extern void update_pm_runtime_accounting(struct device *dev); diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index ca7bd3f98cb4..83b0ea302a80 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -7,6 +7,7 @@ #include #include #include +#include #define PM_QOS_RESERVED 0 #define PM_QOS_CPU_DMA_LATENCY 1 @@ -77,6 +78,7 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_request_active(struct pm_qos_request *req); s32 pm_qos_read_value(struct pm_qos_constraints *c); +s32 dev_pm_qos_read_value(struct device *dev); int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, s32 value); int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value); @@ -117,6 +119,8 @@ static inline int pm_qos_request_active(struct pm_qos_request *req) static inline s32 pm_qos_read_value(struct pm_qos_constraints *c) { return 0; } +static inline s32 dev_pm_qos_read_value(struct device *dev) + { return 0; } static inline int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, s32 value) @@ -139,9 +143,13 @@ static inline int dev_pm_qos_remove_global_notifier( struct notifier_block *notifier) { return 0; } static inline void dev_pm_qos_constraints_init(struct device *dev) - { return; } +{ + dev->power.power_state = PMSG_ON; +} static inline void dev_pm_qos_constraints_destroy(struct device *dev) - { return; } +{ + dev->power.power_state = PMSG_INVALID; +} #endif #endif -- cgit v1.2.3-59-g8ed1b From e3cba3243eb853a052613c804dea033bc4c9cf2d Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Tue, 4 Oct 2011 21:54:45 +0200 Subject: PM / QoS: Update Documentation for the pm_qos and dev_pm_qos frameworks Update the documentation for the recently updated pm_qos API, kernel and user space. Add documentation for the per-device PM QoS (dev_pm_qos) framework API. Signed-off-by: Jean Pihet Signed-off-by: Rafael J. Wysocki --- Documentation/power/pm_qos_interface.txt | 92 ++++++++++++++++++++++++++++++-- 1 file changed, 87 insertions(+), 5 deletions(-) diff --git a/Documentation/power/pm_qos_interface.txt b/Documentation/power/pm_qos_interface.txt index bfed898a03fc..17e130a80347 100644 --- a/Documentation/power/pm_qos_interface.txt +++ b/Documentation/power/pm_qos_interface.txt @@ -4,14 +4,19 @@ This interface provides a kernel and user mode interface for registering performance expectations by drivers, subsystems and user space applications on one of the parameters. -Currently we have {cpu_dma_latency, network_latency, network_throughput} as the -initial set of pm_qos parameters. +Two different PM QoS frameworks are available: +1. PM QoS classes for cpu_dma_latency, network_latency, network_throughput. +2. the per-device PM QoS framework provides the API to manage the per-device latency +constraints. Each parameters have defined units: * latency: usec * timeout: usec * throughput: kbs (kilo bit / sec) + +1. PM QoS framework + The infrastructure exposes multiple misc device nodes one per implemented parameter. The set of parameters implement is defined by pm_qos_power_init() and pm_qos_params.h. This is done because having the available parameters @@ -23,14 +28,18 @@ an aggregated target value. The aggregated target value is updated with changes to the request list or elements of the list. Typically the aggregated target value is simply the max or min of the request values held in the parameter list elements. +Note: the aggregated target value is implemented as an atomic variable so that +reading the aggregated value does not require any locking mechanism. + From kernel mode the use of this interface is simple: -handle = pm_qos_add_request(param_class, target_value): -Will insert an element into the list for that identified PM_QOS class with the +void pm_qos_add_request(handle, param_class, target_value): +Will insert an element into the list for that identified PM QoS class with the target value. Upon change to this list the new target is recomputed and any registered notifiers are called only if the target value is now different. -Clients of pm_qos need to save the returned handle. +Clients of pm_qos need to save the returned handle for future use in other +pm_qos API functions. void pm_qos_update_request(handle, new_target_value): Will update the list element pointed to by the handle with the new target value @@ -42,6 +51,20 @@ Will remove the element. After removal it will update the aggregate target and call the notification tree if the target was changed as a result of removing the request. +int pm_qos_request(param_class): +Returns the aggregated value for a given PM QoS class. + +int pm_qos_request_active(handle): +Returns if the request is still active, i.e. it has not been removed from a +PM QoS class constraints list. + +int pm_qos_add_notifier(param_class, notifier): +Adds a notification callback function to the PM QoS class. The callback is +called when the aggregated value for the PM QoS class is changed. + +int pm_qos_remove_notifier(int param_class, notifier): +Removes the notification callback function for the PM QoS class. + From user mode: Only processes can register a pm_qos request. To provide for automatic @@ -63,4 +86,63 @@ To remove the user mode request for a target value simply close the device node. +2. PM QoS per-device latency framework + +For each device a list of performance requests is maintained along with +an aggregated target value. The aggregated target value is updated with +changes to the request list or elements of the list. Typically the +aggregated target value is simply the max or min of the request values held +in the parameter list elements. +Note: the aggregated target value is implemented as an atomic variable so that +reading the aggregated value does not require any locking mechanism. + + +From kernel mode the use of this interface is the following: + +int dev_pm_qos_add_request(device, handle, value): +Will insert an element into the list for that identified device with the +target value. Upon change to this list the new target is recomputed and any +registered notifiers are called only if the target value is now different. +Clients of dev_pm_qos need to save the handle for future use in other +dev_pm_qos API functions. + +int dev_pm_qos_update_request(handle, new_value): +Will update the list element pointed to by the handle with the new target value +and recompute the new aggregated target, calling the notification trees if the +target is changed. + +int dev_pm_qos_remove_request(handle): +Will remove the element. After removal it will update the aggregate target and +call the notification trees if the target was changed as a result of removing +the request. + +s32 dev_pm_qos_read_value(device): +Returns the aggregated value for a given device's constraints list. + + +Notification mechanisms: +The per-device PM QoS framework has 2 different and distinct notification trees: +a per-device notification tree and a global notification tree. + +int dev_pm_qos_add_notifier(device, notifier): +Adds a notification callback function for the device. +The callback is called when the aggregated value of the device constraints list +is changed. + +int dev_pm_qos_remove_notifier(device, notifier): +Removes the notification callback function for the device. + +int dev_pm_qos_add_global_notifier(notifier): +Adds a notification callback function in the global notification tree of the +framework. +The callback is called when the aggregated value for any device is changed. + +int dev_pm_qos_remove_global_notifier(notifier): +Removes the notification callback function from the global notification tree +of the framework. + + +From user mode: +No API for user space access to the per-device latency constraints is provided +yet - still under discussion. -- cgit v1.2.3-59-g8ed1b