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 --- kernel/power/qos.c | 123 +++++++++++++++++++++++++++++------------------------ 1 file changed, 67 insertions(+), 56 deletions(-) (limited to 'kernel/power') 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