From 3a4a0042228a854d9b1073050620820b4a977e6e Mon Sep 17 00:00:00 2001 From: Rafael J. Wysocki Date: Wed, 12 Feb 2020 00:02:30 +0100 Subject: PM: QoS: Drop PM_QOS_CPU_DMA_LATENCY notifier chain Notice that pm_qos_remove_notifier() is not used at all and the only caller of pm_qos_add_notifier() is the cpuidle core, which only needs the PM_QOS_CPU_DMA_LATENCY notifier to invoke wake_up_all_idle_cpus() upon changes of the PM_QOS_CPU_DMA_LATENCY target value. First, to ensure that wake_up_all_idle_cpus() will be called whenever the PM_QOS_CPU_DMA_LATENCY target value changes, modify the pm_qos_add/update/remove_request() family of functions to check if the effective constraint for the PM_QOS_CPU_DMA_LATENCY has changed and call wake_up_all_idle_cpus() directly in that case. Next, drop the PM_QOS_CPU_DMA_LATENCY notifier from cpuidle as it is not necessary any more. Finally, drop both pm_qos_add_notifier() and pm_qos_remove_notifier(), as they have no callers now, along with cpu_dma_lat_notifier which is only used by them. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- kernel/power/qos.c | 47 +++++++++++------------------------------------ 1 file changed, 11 insertions(+), 36 deletions(-) (limited to 'kernel/power') diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 952c5f55e23c..201b43bc6457 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -56,14 +56,12 @@ */ static DEFINE_SPINLOCK(pm_qos_lock); -static BLOCKING_NOTIFIER_HEAD(cpu_dma_lat_notifier); 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, .no_constraint_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE, .type = PM_QOS_MIN, - .notifiers = &cpu_dma_lat_notifier, }; /** @@ -247,6 +245,14 @@ int pm_qos_request_active(struct pm_qos_request *req) } EXPORT_SYMBOL_GPL(pm_qos_request_active); +static void cpu_latency_qos_update(struct pm_qos_request *req, + enum pm_qos_req_action action, s32 value) +{ + int ret = pm_qos_update_target(req->qos, &req->node, action, value); + if (ret > 0) + wake_up_all_idle_cpus(); +} + /** * pm_qos_add_request - inserts new qos request into the list * @req: pointer to a preallocated handle @@ -273,7 +279,7 @@ void pm_qos_add_request(struct pm_qos_request *req, trace_pm_qos_add_request(PM_QOS_CPU_DMA_LATENCY, value); req->qos = &cpu_dma_constraints; - pm_qos_update_target(req->qos, &req->node, PM_QOS_ADD_REQ, value); + cpu_latency_qos_update(req, PM_QOS_ADD_REQ, value); } EXPORT_SYMBOL_GPL(pm_qos_add_request); @@ -302,7 +308,7 @@ void pm_qos_update_request(struct pm_qos_request *req, s32 new_value) if (new_value == req->node.prio) return; - pm_qos_update_target(req->qos, &req->node, PM_QOS_UPDATE_REQ, new_value); + cpu_latency_qos_update(req, PM_QOS_UPDATE_REQ, new_value); } EXPORT_SYMBOL_GPL(pm_qos_update_request); @@ -327,42 +333,11 @@ void pm_qos_remove_request(struct pm_qos_request *req) trace_pm_qos_remove_request(PM_QOS_CPU_DMA_LATENCY, PM_QOS_DEFAULT_VALUE); - pm_qos_update_target(req->qos, &req->node, PM_QOS_REMOVE_REQ, - PM_QOS_DEFAULT_VALUE); + cpu_latency_qos_update(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); memset(req, 0, sizeof(*req)); } EXPORT_SYMBOL_GPL(pm_qos_remove_request); -/** - * pm_qos_add_notifier - sets notification entry for changes to target value - * @pm_qos_class: Ignored. - * @notifier: notifier block managed by caller. - * - * will register the notifier into a notification chain that gets called - * upon changes to the PM_QOS_CPU_DMA_LATENCY target value. - */ -int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier) -{ - return blocking_notifier_chain_register(cpu_dma_constraints.notifiers, - notifier); -} -EXPORT_SYMBOL_GPL(pm_qos_add_notifier); - -/** - * pm_qos_remove_notifier - deletes notification entry from chain. - * @pm_qos_class: Ignored. - * @notifier: notifier block to be removed. - * - * will remove the notifier from the notification chain that gets called - * upon changes to the PM_QOS_CPU_DMA_LATENCY target value. - */ -int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier) -{ - return blocking_notifier_chain_unregister(cpu_dma_constraints.notifiers, - notifier); -} -EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); - /* User space interface to global PM QoS via misc device. */ static int pm_qos_power_open(struct inode *inode, struct file *filp) -- cgit v1.2.3