From 34896620422eefe1bad998ed4b48117426ad81f9 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 11 Feb 2020 23:52:35 +0100 Subject: PM: QoS: Drop debugfs interface After commit c3082a674f46 ("PM: QoS: Get rid of unused flags") the only global PM QoS class in use is PM_QOS_CPU_DMA_LATENCY and the existing PM QoS debugfs interface has become overly complicated (as it takes other potentially possible PM QoS classes that are not there any more into account). It is also not particularly useful (the "type" of the PM_QOS_CPU_DMA_LATENCY is known, its aggregate value can be read from /dev/cpu_dma_latency and the number of requests in the queue does not really matter) and there are no known users depending on it. Moreover, there are dedicated trace events that can be used for tracking PM QoS usage with much higher precision. For these reasons, drop the PM QoS debugfs interface altogether. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson --- kernel/power/qos.c | 73 ++---------------------------------------------------- 1 file changed, 2 insertions(+), 71 deletions(-) (limited to 'kernel') diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 83edf8698118..d932fa42e8e4 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -137,69 +137,6 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) c->target_value = value; } -static int pm_qos_debug_show(struct seq_file *s, void *unused) -{ - struct pm_qos_object *qos = (struct pm_qos_object *)s->private; - struct pm_qos_constraints *c; - struct pm_qos_request *req; - char *type; - unsigned long flags; - int tot_reqs = 0; - int active_reqs = 0; - - if (IS_ERR_OR_NULL(qos)) { - pr_err("%s: bad qos param!\n", __func__); - return -EINVAL; - } - c = qos->constraints; - if (IS_ERR_OR_NULL(c)) { - pr_err("%s: Bad constraints on qos?\n", __func__); - return -EINVAL; - } - - /* Lock to ensure we have a snapshot */ - spin_lock_irqsave(&pm_qos_lock, flags); - if (plist_head_empty(&c->list)) { - seq_puts(s, "Empty!\n"); - goto out; - } - - switch (c->type) { - case PM_QOS_MIN: - type = "Minimum"; - break; - case PM_QOS_MAX: - type = "Maximum"; - break; - case PM_QOS_SUM: - type = "Sum"; - break; - default: - type = "Unknown"; - } - - plist_for_each_entry(req, &c->list, node) { - char *state = "Default"; - - if ((req->node).prio != c->default_value) { - active_reqs++; - state = "Active"; - } - tot_reqs++; - seq_printf(s, "%d: %d: %s\n", tot_reqs, - (req->node).prio, state); - } - - seq_printf(s, "Type=%s, Value=%d, Requests: active=%d / total=%d\n", - type, pm_qos_get_value(c), active_reqs, tot_reqs); - -out: - spin_unlock_irqrestore(&pm_qos_lock, flags); - return 0; -} - -DEFINE_SHOW_ATTRIBUTE(pm_qos_debug); - /** * pm_qos_update_target - manages the constraints list and calls the notifiers * if needed @@ -529,15 +466,12 @@ 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, struct dentry *d) +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; - debugfs_create_file(qos->name, S_IRUGO, d, (void *)qos, - &pm_qos_debug_fops); - return misc_register(&qos->pm_qos_power_miscdev); } @@ -631,14 +565,11 @@ static int __init pm_qos_power_init(void) { int ret = 0; int i; - struct dentry *d; BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); - d = debugfs_create_dir("pm_qos", NULL); - for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) { - ret = register_pm_qos_misc(pm_qos_array[i], d); + ret = register_pm_qos_misc(pm_qos_array[i]); if (ret < 0) { pr_err("%s: %s setup failed\n", __func__, pm_qos_array[i]->name); -- cgit v1.2.3 From 5a7ea52b6faec6f8877e49645a80349b2d970f0a Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 11 Feb 2020 23:58:17 +0100 Subject: PM: QoS: Drop pm_qos_update_request_timeout() The pm_qos_update_request_timeout() function is not called from anywhere, so drop it along with the work member in struct pm_qos_request needed by it. Also drop the useless pm_qos_update_request_timeout trace event that is only triggered by that function (so it never triggers at all) and update the trace events documentation accordingly. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- Documentation/trace/events-power.rst | 2 -- include/linux/pm_qos.h | 4 --- include/trace/events/power.h | 24 ------------------ kernel/power/qos.c | 48 ------------------------------------ 4 files changed, 78 deletions(-) (limited to 'kernel') diff --git a/Documentation/trace/events-power.rst b/Documentation/trace/events-power.rst index 2ef318962e29..eec7453a168e 100644 --- a/Documentation/trace/events-power.rst +++ b/Documentation/trace/events-power.rst @@ -78,11 +78,9 @@ target/flags update. pm_qos_add_request "pm_qos_class=%s value=%d" pm_qos_update_request "pm_qos_class=%s value=%d" pm_qos_remove_request "pm_qos_class=%s value=%d" - pm_qos_update_request_timeout "pm_qos_class=%s value=%d, timeout_us=%ld" The first parameter gives the QoS class name (e.g. "CPU_DMA_LATENCY"). The second parameter is value to be added/updated/removed. -The third parameter is timeout value in usec. :: pm_qos_update_target "action=%s prev_value=%d curr_value=%d" diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 19eafca5680e..4747bdb6bed2 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -8,7 +8,6 @@ #include #include #include -#include enum { PM_QOS_RESERVED = 0, @@ -43,7 +42,6 @@ enum pm_qos_flags_status { struct pm_qos_request { struct plist_node node; int pm_qos_class; - struct delayed_work work; /* for pm_qos_update_request_timeout */ }; struct pm_qos_flags_request { @@ -149,8 +147,6 @@ 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_update_request_timeout(struct pm_qos_request *req, - s32 new_value, unsigned long timeout_us); void pm_qos_remove_request(struct pm_qos_request *req); int pm_qos_request(int pm_qos_class); diff --git a/include/trace/events/power.h b/include/trace/events/power.h index 7457e238e1b7..ecf39daabf16 100644 --- a/include/trace/events/power.h +++ b/include/trace/events/power.h @@ -404,30 +404,6 @@ DEFINE_EVENT(pm_qos_request, pm_qos_remove_request, TP_ARGS(pm_qos_class, value) ); -TRACE_EVENT(pm_qos_update_request_timeout, - - TP_PROTO(int pm_qos_class, s32 value, unsigned long timeout_us), - - TP_ARGS(pm_qos_class, value, timeout_us), - - TP_STRUCT__entry( - __field( int, pm_qos_class ) - __field( s32, value ) - __field( unsigned long, timeout_us ) - ), - - TP_fast_assign( - __entry->pm_qos_class = pm_qos_class; - __entry->value = value; - __entry->timeout_us = timeout_us; - ), - - TP_printk("pm_qos_class=%s value=%d, timeout_us=%ld", - __print_symbolic(__entry->pm_qos_class, - { PM_QOS_CPU_DMA_LATENCY, "CPU_DMA_LATENCY" }), - __entry->value, __entry->timeout_us) -); - DECLARE_EVENT_CLASS(pm_qos_update, TP_PROTO(enum pm_qos_req_action action, int prev_value, int curr_value), diff --git a/kernel/power/qos.c b/kernel/power/qos.c index d932fa42e8e4..67dab7f330e4 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -295,21 +295,6 @@ static void __pm_qos_update_request(struct pm_qos_request *req, &req->node, PM_QOS_UPDATE_REQ, new_value); } -/** - * pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout - * @work: work struct for the delayed work (timeout) - * - * This cancels the timeout request by falling back to the default at timeout. - */ -static void pm_qos_work_fn(struct work_struct *work) -{ - struct pm_qos_request *req = container_of(to_delayed_work(work), - struct pm_qos_request, - work); - - __pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE); -} - /** * pm_qos_add_request - inserts new qos request into the list * @req: pointer to a preallocated handle @@ -334,7 +319,6 @@ void pm_qos_add_request(struct pm_qos_request *req, return; } req->pm_qos_class = pm_qos_class; - INIT_DELAYED_WORK(&req->work, pm_qos_work_fn); trace_pm_qos_add_request(pm_qos_class, value); pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, &req->node, PM_QOS_ADD_REQ, value); @@ -362,40 +346,10 @@ void pm_qos_update_request(struct pm_qos_request *req, return; } - cancel_delayed_work_sync(&req->work); __pm_qos_update_request(req, new_value); } EXPORT_SYMBOL_GPL(pm_qos_update_request); -/** - * pm_qos_update_request_timeout - modifies an existing qos request temporarily. - * @req : handle to list element holding a pm_qos request to use - * @new_value: defines the temporal qos request - * @timeout_us: the effective duration of this qos request in usecs. - * - * After timeout_us, this qos request is cancelled automatically. - */ -void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value, - unsigned long timeout_us) -{ - if (!req) - return; - if (WARN(!pm_qos_request_active(req), - "%s called for unknown object.", __func__)) - return; - - cancel_delayed_work_sync(&req->work); - - trace_pm_qos_update_request_timeout(req->pm_qos_class, - new_value, timeout_us); - 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); - - schedule_delayed_work(&req->work, usecs_to_jiffies(timeout_us)); -} - /** * pm_qos_remove_request - modifies an existing qos request * @req: handle to request list element @@ -415,8 +369,6 @@ void pm_qos_remove_request(struct pm_qos_request *req) return; } - cancel_delayed_work_sync(&req->work); - trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE); pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, &req->node, PM_QOS_REMOVE_REQ, -- cgit v1.2.3 From 87ad7356799622b69478076cd99df7a5024992cb Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 11 Feb 2020 23:58:26 +0100 Subject: PM: QoS: Drop the PM_QOS_SUM QoS type The PM_QOS_SUM QoS type is not used, so drop it along with the code referring to it in pm_qos_get_value() and the related local variables in there. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- include/linux/pm_qos.h | 1 - kernel/power/qos.c | 9 --------- 2 files changed, 10 deletions(-) (limited to 'kernel') diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 4747bdb6bed2..48bfb96a9360 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -53,7 +53,6 @@ enum pm_qos_type { PM_QOS_UNITIALIZED, PM_QOS_MAX, /* return the largest value */ PM_QOS_MIN, /* return the smallest value */ - PM_QOS_SUM /* return the sum */ }; /* diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 67dab7f330e4..a6be7faa1974 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -101,9 +101,6 @@ static const struct file_operations pm_qos_power_fops = { /* unlocked internal variant */ static inline int pm_qos_get_value(struct pm_qos_constraints *c) { - struct plist_node *node; - int total_value = 0; - if (plist_head_empty(&c->list)) return c->no_constraint_value; @@ -114,12 +111,6 @@ static inline int pm_qos_get_value(struct pm_qos_constraints *c) case PM_QOS_MAX: return plist_last(&c->list)->prio; - case PM_QOS_SUM: - plist_for_each(node, &c->list) - total_value += node->prio; - - return total_value; - default: /* runtime check for not using enum */ BUG(); -- cgit v1.2.3 From 7b35370b2ebc2608ba0f2e0ecb996fa7f38e9731 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 11 Feb 2020 23:58:33 +0100 Subject: PM: QoS: Clean up pm_qos_update_target() and pm_qos_update_flags() Clean up the pm_qos_update_target() function: * Update its kerneldoc comment. * Drop the redundant ret local variable from it. * Reorder definitions of local variables in it. * Update a comment in it. Also update the kerneldoc comment of pm_qos_update_flags() (e.g. notifiers are not called by it any more) and add one emtpy line to its body (for more visual clarity). No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- kernel/power/qos.c | 56 ++++++++++++++++++++++++++++-------------------------- 1 file changed, 29 insertions(+), 27 deletions(-) (limited to 'kernel') diff --git a/kernel/power/qos.c b/kernel/power/qos.c index a6be7faa1974..6a36809d6160 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -129,24 +129,30 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 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 + * pm_qos_update_target - Update a list of PM QoS constraint requests. + * @c: List of PM QoS requests. + * @node: Target list entry. + * @action: Action to carry out (add, update or remove). + * @value: New request value for the target list entry. * - * This function returns 1 if the aggregated constraint value has changed, 0 - * otherwise. + * Update the given list of PM QoS constraint requests, @c, by carrying an + * @action involving the @node list entry and @value on it. + * + * The recognized values of @action are PM_QOS_ADD_REQ (store @value in @node + * and add it to the list), PM_QOS_UPDATE_REQ (remove @node from the list, store + * @value in it and add it to the list again), and PM_QOS_REMOVE_REQ (remove + * @node from the list, ignore @value). + * + * Return: 1 if the aggregate 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, new_value; - int ret; + unsigned long flags; spin_lock_irqsave(&pm_qos_lock, flags); + prev_value = pm_qos_get_value(c); if (value == PM_QOS_DEFAULT_VALUE) new_value = c->default_value; @@ -159,9 +165,8 @@ int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, 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 + * To change the list, atomically remove, reinit with new value + * and add, then see if the aggregate has changed. */ plist_del(node, &c->list); /* fall through */ @@ -180,16 +185,14 @@ int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, spin_unlock_irqrestore(&pm_qos_lock, flags); trace_pm_qos_update_target(action, prev_value, curr_value); - if (prev_value != curr_value) { - ret = 1; - if (c->notifiers) - blocking_notifier_call_chain(c->notifiers, - (unsigned long)curr_value, - NULL); - } else { - ret = 0; - } - return ret; + + if (prev_value == curr_value) + return 0; + + if (c->notifiers) + blocking_notifier_call_chain(c->notifiers, curr_value, NULL); + + return 1; } /** @@ -211,14 +214,12 @@ static void pm_qos_flags_remove_req(struct pm_qos_flags *pqf, /** * pm_qos_update_flags - Update a set of PM QoS flags. - * @pqf: Set of flags to update. + * @pqf: Set of PM QoS flags to update. * @req: Request to add to the set, to modify, or to remove from the set. * @action: Action to take on the set. * @val: Value of the request to add or modify. * - * Update the given set of PM QoS flags and call notifiers if the aggregate - * value has changed. Returns 1 if the aggregate constraint value has changed, - * 0 otherwise. + * Return: 1 if the aggregate constraint value has changed, 0 otherwise. */ bool pm_qos_update_flags(struct pm_qos_flags *pqf, struct pm_qos_flags_request *req, @@ -254,6 +255,7 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf, spin_unlock_irqrestore(&pm_qos_lock, irqflags); trace_pm_qos_update_flags(action, prev_value, curr_value); + return prev_value != curr_value; } -- cgit v1.2.3 From dcd70ca1a3bf33aa5cf53aa6f72b8e51afb1ac48 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 11 Feb 2020 23:58:39 +0100 Subject: PM: QoS: Clean up pm_qos_read_value() and pm_qos_get/set_value() Move the definition of pm_qos_read_value() before the one of pm_qos_get_value() and add a kerneldoc comment to it (as it is not static). Also replace the BUG() in pm_qos_get_value() with WARN() (to prevent the kernel from crashing if an unknown PM QoS type is used by mistake) and drop the comment next to it that is not necessary any more. Additionally, drop the unnecessary inline modifier from the header of pm_qos_set_value(). Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- kernel/power/qos.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 6a36809d6160..f09eca5ffe07 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -98,8 +98,16 @@ static const struct file_operations pm_qos_power_fops = { .llseek = noop_llseek, }; -/* unlocked internal variant */ -static inline int pm_qos_get_value(struct pm_qos_constraints *c) +/** + * pm_qos_read_value - Return the current effective constraint value. + * @c: List of PM QoS constraint requests. + */ +s32 pm_qos_read_value(struct pm_qos_constraints *c) +{ + return c->target_value; +} + +static int pm_qos_get_value(struct pm_qos_constraints *c) { if (plist_head_empty(&c->list)) return c->no_constraint_value; @@ -112,18 +120,12 @@ static inline int pm_qos_get_value(struct pm_qos_constraints *c) return plist_last(&c->list)->prio; default: - /* runtime check for not using enum */ - BUG(); + WARN(1, "Unknown PM QoS type in %s\n", __func__); return PM_QOS_DEFAULT_VALUE; } } -s32 pm_qos_read_value(struct pm_qos_constraints *c) -{ - return c->target_value; -} - -static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) +static void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) { c->target_value = value; } -- cgit v1.2.3 From 63cffc05348ea1fe65aa99e80ed330e33bf54220 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 11 Feb 2020 23:59:22 +0100 Subject: PM: QoS: Drop iterations over global QoS classes After commit c3082a674f46 ("PM: QoS: Get rid of unused flags") the only global PM QoS class in use is PM_QOS_CPU_DMA_LATENCY, so it does not really make sense to iterate over global QoS classes anywhere, since there is only one. Remove iterations over global QoS classes from the code and use PM_QOS_CPU_DMA_LATENCY as the target class directly where needed. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- kernel/power/qos.c | 52 ++++++++++++++-------------------------------------- 1 file changed, 14 insertions(+), 38 deletions(-) (limited to 'kernel') diff --git a/kernel/power/qos.c b/kernel/power/qos.c index f09eca5ffe07..57ff542a4f9d 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -412,7 +412,8 @@ 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 */ +/* User space interface to global PM QoS via misc device. */ + static int register_pm_qos_misc(struct pm_qos_object *qos) { qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR; @@ -422,35 +423,18 @@ static int register_pm_qos_misc(struct pm_qos_object *qos) 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 = PM_QOS_CPU_DMA_LATENCY; - 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; + struct pm_qos_request *req; - pm_qos_class = find_pm_qos_object_by_minor(iminor(inode)); - if (pm_qos_class >= PM_QOS_CPU_DMA_LATENCY) { - struct pm_qos_request *req = kzalloc(sizeof(*req), GFP_KERNEL); - if (!req) - return -ENOMEM; + 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; + pm_qos_add_request(req, PM_QOS_CPU_DMA_LATENCY, PM_QOS_DEFAULT_VALUE); + filp->private_data = req; - return 0; - } - return -EPERM; + return 0; } static int pm_qos_power_release(struct inode *inode, struct file *filp) @@ -464,7 +448,6 @@ static int pm_qos_power_release(struct inode *inode, struct file *filp) return 0; } - static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) { @@ -507,26 +490,19 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, return count; } - static int __init pm_qos_power_init(void) { - int ret = 0; - int i; + int ret; BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); - for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) { - ret = register_pm_qos_misc(pm_qos_array[i]); - if (ret < 0) { - pr_err("%s: %s setup failed\n", - __func__, pm_qos_array[i]->name); - return ret; - } - } + ret = register_pm_qos_misc(pm_qos_array[PM_QOS_CPU_DMA_LATENCY]); + if (ret < 0) + pr_err("%s: %s setup failed\n", __func__, + pm_qos_array[PM_QOS_CPU_DMA_LATENCY]->name); return ret; } - late_initcall(pm_qos_power_init); /* Definitions related to the frequency QoS below. */ -- cgit v1.2.3 From 299a229830a29a2d691ac17b27964c7d820f16a6 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 12 Feb 2020 00:00:12 +0100 Subject: PM: QoS: Clean up misc device file operations Reorder the code to avoid using extra function header declarations for the pm_qos_power_*() family of functions and drop those declarations. Also clean up the internals of those functions to consolidate checks, avoid using redundant local variables and similar. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- kernel/power/qos.c | 62 +++++++++++++++++++++++------------------------------- 1 file changed, 26 insertions(+), 36 deletions(-) (limited to 'kernel') diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 57ff542a4f9d..9f67584d4466 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -83,21 +83,6 @@ static struct pm_qos_object *pm_qos_array[] = { &cpu_dma_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, -}; - /** * pm_qos_read_value - Return the current effective constraint value. * @c: List of PM QoS constraint requests. @@ -414,15 +399,6 @@ EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); /* User space interface to global PM QoS via misc device. */ -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 pm_qos_power_open(struct inode *inode, struct file *filp) { struct pm_qos_request *req; @@ -439,9 +415,10 @@ 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 *req; + struct pm_qos_request *req = filp->private_data; + + filp->private_data = NULL; - req = filp->private_data; pm_qos_remove_request(req); kfree(req); @@ -449,15 +426,13 @@ static int pm_qos_power_release(struct inode *inode, struct file *filp) } static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, - size_t count, loff_t *f_pos) + size_t count, loff_t *f_pos) { - s32 value; - unsigned long flags; struct pm_qos_request *req = filp->private_data; + unsigned long flags; + s32 value; - if (!req) - return -EINVAL; - if (!pm_qos_request_active(req)) + if (!req || !pm_qos_request_active(req)) return -EINVAL; spin_lock_irqsave(&pm_qos_lock, flags); @@ -468,10 +443,9 @@ static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, } static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, - size_t count, loff_t *f_pos) + size_t count, loff_t *f_pos) { s32 value; - struct pm_qos_request *req; if (count == sizeof(s32)) { if (copy_from_user(&value, buf, sizeof(s32))) @@ -484,12 +458,28 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, return ret; } - req = filp->private_data; - pm_qos_update_request(req, value); + pm_qos_update_request(filp->private_data, value); return count; } +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, +}; + +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 __init pm_qos_power_init(void) { int ret; -- cgit v1.2.3 From 02c92a378940ba1a46b6b7ad277f1b07f8093dbc Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 12 Feb 2020 00:01:18 +0100 Subject: PM: QoS: Redefine struct pm_qos_request and drop struct pm_qos_object First, change the definition of struct pm_qos_request so that it contains a struct pm_qos_constraints pointer (called "qos") instead of a PM QoS class number (in preparation for dropping the PM QoS classes concept altogether going forward) and move its definition (along with the definition of struct pm_qos_flags_request that does not change) after the definition of struct pm_qos_constraints. Next, drop the definition of struct pm_qos_object and the null_pm_qos and cpu_dma_pm_qos variables of that type along with pm_qos_array[] holding pointers to them and change the code to refer to the pm_qos_constraints structure directly or to use the new qos pointer in struct pm_qos_request for that instead of going through pm_qos_array[] to access it. Also update kerneldoc comments that mention pm_qos_class to refer to PM_QOS_CPU_DMA_LATENCY directly instead. Finally, drop register_pm_qos_misc(), introduce cpu_latency_qos_miscdev (with the name field set to "cpu_dma_latency") to implement the CPU latency QoS interface in /dev/ and register it directly from pm_qos_power_init(). After these changes the notion of PM QoS classes remains only in the API (in the form of redundant function parameters that are ignored) and in the definitions of PM QoS trace events. While at it, some redundant local variables are dropped etc. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- include/linux/pm_qos.h | 20 ++++---- kernel/power/qos.c | 121 +++++++++++++++++-------------------------------- 2 files changed, 51 insertions(+), 90 deletions(-) (limited to 'kernel') diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 48bfb96a9360..bef110aa80cc 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -39,16 +39,6 @@ enum pm_qos_flags_status { #define PM_QOS_FLAG_NO_POWER_OFF (1 << 0) -struct pm_qos_request { - struct plist_node node; - int pm_qos_class; -}; - -struct pm_qos_flags_request { - struct list_head node; - s32 flags; /* Do not change to 64 bit */ -}; - enum pm_qos_type { PM_QOS_UNITIALIZED, PM_QOS_MAX, /* return the largest value */ @@ -69,6 +59,16 @@ struct pm_qos_constraints { struct blocking_notifier_head *notifiers; }; +struct pm_qos_request { + struct plist_node node; + struct pm_qos_constraints *qos; +}; + +struct pm_qos_flags_request { + struct list_head node; + s32 flags; /* Do not change to 64 bit */ +}; + struct pm_qos_flags { struct list_head list; s32 effective_flags; /* Do not change to 64 bit */ diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 9f67584d4466..952c5f55e23c 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -54,16 +54,8 @@ * 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 */ -struct pm_qos_object { - struct pm_qos_constraints *constraints; - struct miscdevice pm_qos_power_miscdev; - char *name; -}; - 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_constraints cpu_dma_constraints = { .list = PLIST_HEAD_INIT(cpu_dma_constraints.list), @@ -73,15 +65,6 @@ static struct pm_qos_constraints cpu_dma_constraints = { .type = PM_QOS_MIN, .notifiers = &cpu_dma_lat_notifier, }; -static struct pm_qos_object cpu_dma_pm_qos = { - .constraints = &cpu_dma_constraints, - .name = "cpu_dma_latency", -}; - -static struct pm_qos_object *pm_qos_array[] = { - &null_pm_qos, - &cpu_dma_pm_qos, -}; /** * pm_qos_read_value - Return the current effective constraint value. @@ -248,46 +231,34 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf, /** * pm_qos_request - returns current system wide qos expectation - * @pm_qos_class: identification of which qos value is requested + * @pm_qos_class: Ignored. * * 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]->constraints); + return pm_qos_read_value(&cpu_dma_constraints); } EXPORT_SYMBOL_GPL(pm_qos_request); int pm_qos_request_active(struct pm_qos_request *req) { - return req->pm_qos_class != 0; + return req->qos == &cpu_dma_constraints; } EXPORT_SYMBOL_GPL(pm_qos_request_active); -static void __pm_qos_update_request(struct pm_qos_request *req, - s32 new_value) -{ - trace_pm_qos_update_request(req->pm_qos_class, new_value); - - 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); -} - /** * pm_qos_add_request - inserts new qos request into the list * @req: pointer to a preallocated handle - * @pm_qos_class: identifies which list of qos request to use + * @pm_qos_class: Ignored. * @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 + * This function inserts a new entry in the PM_QOS_CPU_DMA_LATENCY list of + * requested QoS performance characteristics. It recomputes the aggregate QoS + * expectations for the PM_QOS_CPU_DMA_LATENCY list and initializes the @req * handle. Caller needs to save this handle for later use in updates and * removal. */ - void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class, s32 value) { @@ -298,10 +269,11 @@ void pm_qos_add_request(struct pm_qos_request *req, WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); return; } - req->pm_qos_class = pm_qos_class; - trace_pm_qos_add_request(pm_qos_class, value); - pm_qos_update_target(pm_qos_array[pm_qos_class]->constraints, - &req->node, PM_QOS_ADD_REQ, value); + + 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); } EXPORT_SYMBOL_GPL(pm_qos_add_request); @@ -310,13 +282,12 @@ EXPORT_SYMBOL_GPL(pm_qos_add_request); * @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. + * Updates an existing qos request for the PM_QOS_CPU_DMA_LATENCY list along + * with updating the target PM_QOS_CPU_DMA_LATENCY value. * * Attempts are made to make this code callable on hot code paths. */ -void pm_qos_update_request(struct pm_qos_request *req, - s32 new_value) +void pm_qos_update_request(struct pm_qos_request *req, s32 new_value) { if (!req) /*guard against callers passing in null */ return; @@ -326,7 +297,12 @@ void pm_qos_update_request(struct pm_qos_request *req, return; } - __pm_qos_update_request(req, new_value); + trace_pm_qos_update_request(PM_QOS_CPU_DMA_LATENCY, new_value); + + if (new_value == req->node.prio) + return; + + pm_qos_update_target(req->qos, &req->node, PM_QOS_UPDATE_REQ, new_value); } EXPORT_SYMBOL_GPL(pm_qos_update_request); @@ -335,7 +311,7 @@ EXPORT_SYMBOL_GPL(pm_qos_update_request); * @req: handle to request list element * * Will remove pm qos request from the list of constraints and - * recompute the current target value for the pm_qos_class. Call this + * recompute the current target value for PM_QOS_CPU_DMA_LATENCY. Call this * on slow code paths. */ void pm_qos_remove_request(struct pm_qos_request *req) @@ -349,9 +325,9 @@ void pm_qos_remove_request(struct pm_qos_request *req) return; } - trace_pm_qos_remove_request(req->pm_qos_class, PM_QOS_DEFAULT_VALUE); - pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints, - &req->node, PM_QOS_REMOVE_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); memset(req, 0, sizeof(*req)); } @@ -359,41 +335,31 @@ 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. + * @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_class target value. + * upon changes to the PM_QOS_CPU_DMA_LATENCY 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]->constraints->notifiers, - notifier); - - return retval; + 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: identifies which qos target changes are notified. + * @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_class target value. + * upon changes to the PM_QOS_CPU_DMA_LATENCY 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]->constraints->notifiers, - notifier); - - return retval; + return blocking_notifier_chain_unregister(cpu_dma_constraints.notifiers, + notifier); } EXPORT_SYMBOL_GPL(pm_qos_remove_notifier); @@ -436,7 +402,7 @@ static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, return -EINVAL; spin_lock_irqsave(&pm_qos_lock, flags); - value = pm_qos_get_value(pm_qos_array[req->pm_qos_class]->constraints); + value = pm_qos_get_value(&cpu_dma_constraints); spin_unlock_irqrestore(&pm_qos_lock, flags); return simple_read_from_buffer(buf, count, f_pos, &value, sizeof(s32)); @@ -471,25 +437,20 @@ static const struct file_operations pm_qos_power_fops = { .llseek = noop_llseek, }; -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 struct miscdevice cpu_latency_qos_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = "cpu_dma_latency", + .fops = &pm_qos_power_fops, +}; static int __init pm_qos_power_init(void) { int ret; - BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES); - - ret = register_pm_qos_misc(pm_qos_array[PM_QOS_CPU_DMA_LATENCY]); + ret = misc_register(&cpu_latency_qos_miscdev); if (ret < 0) pr_err("%s: %s setup failed\n", __func__, - pm_qos_array[PM_QOS_CPU_DMA_LATENCY]->name); + cpu_latency_qos_miscdev.name); return ret; } -- cgit v1.2.3 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 --- drivers/cpuidle/cpuidle.c | 40 +--------------------------------------- include/linux/pm_qos.h | 2 -- kernel/power/qos.c | 47 +++++++++++------------------------------------ 3 files changed, 12 insertions(+), 77 deletions(-) (limited to 'kernel') diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index de81298051b3..c149d9e20dfd 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -736,53 +736,15 @@ int cpuidle_register(struct cpuidle_driver *drv, } EXPORT_SYMBOL_GPL(cpuidle_register); -#ifdef CONFIG_SMP - -/* - * This function gets called when a part of the kernel has a new latency - * requirement. This means we need to get all processors out of their C-state, - * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that - * wakes them all right up. - */ -static int cpuidle_latency_notify(struct notifier_block *b, - unsigned long l, void *v) -{ - wake_up_all_idle_cpus(); - return NOTIFY_OK; -} - -static struct notifier_block cpuidle_latency_notifier = { - .notifier_call = cpuidle_latency_notify, -}; - -static inline void latency_notifier_init(struct notifier_block *n) -{ - pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n); -} - -#else /* CONFIG_SMP */ - -#define latency_notifier_init(x) do { } while (0) - -#endif /* CONFIG_SMP */ - /** * cpuidle_init - core initializer */ static int __init cpuidle_init(void) { - int ret; - if (cpuidle_disabled()) return -ENODEV; - ret = cpuidle_add_interface(cpu_subsys.dev_root); - if (ret) - return ret; - - latency_notifier_init(&cpuidle_latency_notifier); - - return 0; + return cpuidle_add_interface(cpu_subsys.dev_root); } module_param(off, int, 0444); diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index bef110aa80cc..cb57e5918a25 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -149,8 +149,6 @@ void pm_qos_update_request(struct pm_qos_request *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 *req); s32 pm_qos_read_value(struct pm_qos_constraints *c); 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 From 2552d3520132a22834e0be85c51168a7a798608c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 12 Feb 2020 00:04:31 +0100 Subject: PM: QoS: Rename things related to the CPU latency QoS First, rename PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE to PM_QOS_CPU_LATENCY_DEFAULT_VALUE and update all of the code referring to it accordingly. Next, rename cpu_dma_constraints to cpu_latency_constraints, move the definition of it closer to the functions referring to it and update all of them accordingly. [While at it, add a comment to mark the start of the code related to the CPU latency QoS.] Finally, rename the pm_qos_power_*() family of functions and pm_qos_power_fops to cpu_latency_qos_*() and cpu_latency_qos_fops, respectively, and update the definition of cpu_latency_qos_miscdev. [While at it, update the miscdev interface code start comment.] No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Acked-by: Greg Kroah-Hartman Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- drivers/tty/serial/8250/8250_omap.c | 6 ++-- drivers/tty/serial/omap-serial.c | 6 ++-- include/linux/pm_qos.h | 2 +- kernel/power/qos.c | 56 +++++++++++++++++++------------------ 4 files changed, 36 insertions(+), 34 deletions(-) (limited to 'kernel') diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 6f343ca08440..19f8d2f9e7ba 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -1222,8 +1222,8 @@ static int omap8250_probe(struct platform_device *pdev) DEFAULT_CLK_SPEED); } - priv->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE; - priv->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE; + priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; + priv->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; pm_qos_add_request(&priv->pm_qos_request, PM_QOS_CPU_DMA_LATENCY, priv->latency); INIT_WORK(&priv->qos_work, omap8250_uart_qos_work); @@ -1445,7 +1445,7 @@ static int omap8250_runtime_suspend(struct device *dev) if (up->dma && up->dma->rxchan) omap_8250_rx_dma_flush(up); - priv->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE; + priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; schedule_work(&priv->qos_work); return 0; diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 48017cec7f2f..ce2558767eee 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -1722,8 +1722,8 @@ static int serial_omap_probe(struct platform_device *pdev) DEFAULT_CLK_SPEED); } - up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE; - up->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE; + up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; + up->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; pm_qos_add_request(&up->pm_qos_request, PM_QOS_CPU_DMA_LATENCY, up->latency); INIT_WORK(&up->qos_work, serial_omap_uart_qos_work); @@ -1869,7 +1869,7 @@ static int serial_omap_runtime_suspend(struct device *dev) serial_omap_enable_wakeup(up, true); - up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE; + up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; schedule_work(&up->qos_work); return 0; diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index cb57e5918a25..a3e0bfc6c470 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -28,7 +28,7 @@ enum pm_qos_flags_status { #define PM_QOS_LATENCY_ANY S32_MAX #define PM_QOS_LATENCY_ANY_NS ((s64)PM_QOS_LATENCY_ANY * NSEC_PER_USEC) -#define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) +#define PM_QOS_CPU_LATENCY_DEFAULT_VALUE (2000 * USEC_PER_SEC) #define PM_QOS_RESUME_LATENCY_DEFAULT_VALUE PM_QOS_LATENCY_ANY #define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT PM_QOS_LATENCY_ANY #define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT_NS PM_QOS_LATENCY_ANY_NS diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 201b43bc6457..a6bf53e9db17 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -56,14 +56,6 @@ */ static DEFINE_SPINLOCK(pm_qos_lock); -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, -}; - /** * pm_qos_read_value - Return the current effective constraint value. * @c: List of PM QoS constraint requests. @@ -227,6 +219,16 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf, return prev_value != curr_value; } +/* Definitions related to the CPU latency QoS. */ + +static struct pm_qos_constraints cpu_latency_constraints = { + .list = PLIST_HEAD_INIT(cpu_latency_constraints.list), + .target_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE, + .default_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE, + .no_constraint_value = PM_QOS_CPU_LATENCY_DEFAULT_VALUE, + .type = PM_QOS_MIN, +}; + /** * pm_qos_request - returns current system wide qos expectation * @pm_qos_class: Ignored. @@ -235,13 +237,13 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf, */ int pm_qos_request(int pm_qos_class) { - return pm_qos_read_value(&cpu_dma_constraints); + return pm_qos_read_value(&cpu_latency_constraints); } EXPORT_SYMBOL_GPL(pm_qos_request); int pm_qos_request_active(struct pm_qos_request *req) { - return req->qos == &cpu_dma_constraints; + return req->qos == &cpu_latency_constraints; } EXPORT_SYMBOL_GPL(pm_qos_request_active); @@ -278,7 +280,7 @@ 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; + req->qos = &cpu_latency_constraints; cpu_latency_qos_update(req, PM_QOS_ADD_REQ, value); } EXPORT_SYMBOL_GPL(pm_qos_add_request); @@ -338,9 +340,9 @@ void pm_qos_remove_request(struct pm_qos_request *req) } EXPORT_SYMBOL_GPL(pm_qos_remove_request); -/* User space interface to global PM QoS via misc device. */ +/* User space interface to the CPU latency QoS via misc device. */ -static int pm_qos_power_open(struct inode *inode, struct file *filp) +static int cpu_latency_qos_open(struct inode *inode, struct file *filp) { struct pm_qos_request *req; @@ -354,7 +356,7 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp) return 0; } -static int pm_qos_power_release(struct inode *inode, struct file *filp) +static int cpu_latency_qos_release(struct inode *inode, struct file *filp) { struct pm_qos_request *req = filp->private_data; @@ -366,8 +368,8 @@ static int pm_qos_power_release(struct inode *inode, struct file *filp) return 0; } -static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, - size_t count, loff_t *f_pos) +static ssize_t cpu_latency_qos_read(struct file *filp, char __user *buf, + size_t count, loff_t *f_pos) { struct pm_qos_request *req = filp->private_data; unsigned long flags; @@ -377,14 +379,14 @@ static ssize_t pm_qos_power_read(struct file *filp, char __user *buf, return -EINVAL; spin_lock_irqsave(&pm_qos_lock, flags); - value = pm_qos_get_value(&cpu_dma_constraints); + value = pm_qos_get_value(&cpu_latency_constraints); 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) +static ssize_t cpu_latency_qos_write(struct file *filp, const char __user *buf, + size_t count, loff_t *f_pos) { s32 value; @@ -404,21 +406,21 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf, return count; } -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, +static const struct file_operations cpu_latency_qos_fops = { + .write = cpu_latency_qos_write, + .read = cpu_latency_qos_read, + .open = cpu_latency_qos_open, + .release = cpu_latency_qos_release, .llseek = noop_llseek, }; static struct miscdevice cpu_latency_qos_miscdev = { .minor = MISC_DYNAMIC_MINOR, .name = "cpu_dma_latency", - .fops = &pm_qos_power_fops, + .fops = &cpu_latency_qos_fops, }; -static int __init pm_qos_power_init(void) +static int __init cpu_latency_qos_init(void) { int ret; @@ -429,7 +431,7 @@ static int __init pm_qos_power_init(void) return ret; } -late_initcall(pm_qos_power_init); +late_initcall(cpu_latency_qos_init); /* Definitions related to the frequency QoS below. */ -- cgit v1.2.3 From 333eed7d20069e2d80446f5fdf9ac3868b55e7b9 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 12 Feb 2020 00:06:17 +0100 Subject: PM: QoS: Simplify definitions of CPU latency QoS trace events Modify the definitions of the CPU latency QoS trace events to take one argument (since PM_QOS_CPU_DMA_LATENCY is always passed as the pm_qos_class argument to them) and update the documentation of them accordingly (while at it, make it explicitly mention CPU latency QoS and relocate it after the device PM QoS trace events documentation). The names and output format of the trace events do not change to preserve user space compatibility. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- Documentation/trace/events-power.rst | 19 ++++++++++--------- include/trace/events/power.h | 35 +++++++++++++++++------------------ kernel/power/qos.c | 16 ++++++++-------- 3 files changed, 35 insertions(+), 35 deletions(-) (limited to 'kernel') diff --git a/Documentation/trace/events-power.rst b/Documentation/trace/events-power.rst index eec7453a168e..f45bf11fa88d 100644 --- a/Documentation/trace/events-power.rst +++ b/Documentation/trace/events-power.rst @@ -73,14 +73,6 @@ The second parameter is the power domain target state. ================ The PM QoS events are used for QoS add/update/remove request and for target/flags update. -:: - - pm_qos_add_request "pm_qos_class=%s value=%d" - pm_qos_update_request "pm_qos_class=%s value=%d" - pm_qos_remove_request "pm_qos_class=%s value=%d" - -The first parameter gives the QoS class name (e.g. "CPU_DMA_LATENCY"). -The second parameter is value to be added/updated/removed. :: pm_qos_update_target "action=%s prev_value=%d curr_value=%d" @@ -90,7 +82,7 @@ The first parameter gives the QoS action name (e.g. "ADD_REQ"). The second parameter is the previous QoS value. The third parameter is the current QoS value to update. -And, there are also events used for device PM QoS add/update/remove request. +There are also events used for device PM QoS add/update/remove request. :: dev_pm_qos_add_request "device=%s type=%s new_value=%d" @@ -101,3 +93,12 @@ The first parameter gives the device name which tries to add/update/remove QoS requests. The second parameter gives the request type (e.g. "DEV_PM_QOS_RESUME_LATENCY"). The third parameter is value to be added/updated/removed. + +And, there are events used for CPU latency QoS add/update/remove request. +:: + + pm_qos_add_request "value=%d" + pm_qos_update_request "value=%d" + pm_qos_remove_request "value=%d" + +The parameter is the value to be added/updated/removed. diff --git a/include/trace/events/power.h b/include/trace/events/power.h index ecf39daabf16..af5018aa9517 100644 --- a/include/trace/events/power.h +++ b/include/trace/events/power.h @@ -359,51 +359,50 @@ DEFINE_EVENT(power_domain, power_domain_target, ); /* - * The pm qos events are used for pm qos update + * CPU latency QoS events used for global CPU latency QoS list updates */ -DECLARE_EVENT_CLASS(pm_qos_request, +DECLARE_EVENT_CLASS(cpu_latency_qos_request, - TP_PROTO(int pm_qos_class, s32 value), + TP_PROTO(s32 value), - TP_ARGS(pm_qos_class, value), + TP_ARGS(value), TP_STRUCT__entry( - __field( int, pm_qos_class ) __field( s32, value ) ), TP_fast_assign( - __entry->pm_qos_class = pm_qos_class; __entry->value = value; ), - TP_printk("pm_qos_class=%s value=%d", - __print_symbolic(__entry->pm_qos_class, - { PM_QOS_CPU_DMA_LATENCY, "CPU_DMA_LATENCY" }), + TP_printk("CPU_DMA_LATENCY value=%d", __entry->value) ); -DEFINE_EVENT(pm_qos_request, pm_qos_add_request, +DEFINE_EVENT(cpu_latency_qos_request, pm_qos_add_request, - TP_PROTO(int pm_qos_class, s32 value), + TP_PROTO(s32 value), - TP_ARGS(pm_qos_class, value) + TP_ARGS(value) ); -DEFINE_EVENT(pm_qos_request, pm_qos_update_request, +DEFINE_EVENT(cpu_latency_qos_request, pm_qos_update_request, - TP_PROTO(int pm_qos_class, s32 value), + TP_PROTO(s32 value), - TP_ARGS(pm_qos_class, value) + TP_ARGS(value) ); -DEFINE_EVENT(pm_qos_request, pm_qos_remove_request, +DEFINE_EVENT(cpu_latency_qos_request, pm_qos_remove_request, - TP_PROTO(int pm_qos_class, s32 value), + TP_PROTO(s32 value), - TP_ARGS(pm_qos_class, value) + TP_ARGS(value) ); +/* + * General PM QoS events used for updates of PM QoS request lists + */ DECLARE_EVENT_CLASS(pm_qos_update, TP_PROTO(enum pm_qos_req_action action, int prev_value, int curr_value), diff --git a/kernel/power/qos.c b/kernel/power/qos.c index a6bf53e9db17..afac7010e0f2 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -247,8 +247,8 @@ 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) +static void cpu_latency_qos_apply(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) @@ -278,10 +278,10 @@ void pm_qos_add_request(struct pm_qos_request *req, return; } - trace_pm_qos_add_request(PM_QOS_CPU_DMA_LATENCY, value); + trace_pm_qos_add_request(value); req->qos = &cpu_latency_constraints; - cpu_latency_qos_update(req, PM_QOS_ADD_REQ, value); + cpu_latency_qos_apply(req, PM_QOS_ADD_REQ, value); } EXPORT_SYMBOL_GPL(pm_qos_add_request); @@ -305,12 +305,12 @@ void pm_qos_update_request(struct pm_qos_request *req, s32 new_value) return; } - trace_pm_qos_update_request(PM_QOS_CPU_DMA_LATENCY, new_value); + trace_pm_qos_update_request(new_value); if (new_value == req->node.prio) return; - cpu_latency_qos_update(req, PM_QOS_UPDATE_REQ, new_value); + cpu_latency_qos_apply(req, PM_QOS_UPDATE_REQ, new_value); } EXPORT_SYMBOL_GPL(pm_qos_update_request); @@ -333,9 +333,9 @@ void pm_qos_remove_request(struct pm_qos_request *req) return; } - trace_pm_qos_remove_request(PM_QOS_CPU_DMA_LATENCY, PM_QOS_DEFAULT_VALUE); + trace_pm_qos_remove_request(PM_QOS_DEFAULT_VALUE); - cpu_latency_qos_update(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); + cpu_latency_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); memset(req, 0, sizeof(*req)); } EXPORT_SYMBOL_GPL(pm_qos_remove_request); -- cgit v1.2.3 From e033b6c175a32870a2f7cd3741c0d48c858c2d04 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 12 Feb 2020 00:07:01 +0100 Subject: PM: QoS: Adjust pm_qos_request() signature and reorder pm_qos.h Change the return type of pm_qos_request() to be the same as the one of pm_qos_read_value() called by it internally and stop exporting it to modules (because its only caller, cpuidle, is not modular). Also move the pm_qos_read_value() header away from the CPU latency QoS API function headers in pm_qos.h (because it technically does not belong to that API). No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- include/linux/pm_qos.h | 6 +++--- kernel/power/qos.c | 3 +-- 2 files changed, 4 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index a3e0bfc6c470..3c4bee29ecda 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -137,20 +137,20 @@ static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req) return req->dev != NULL; } +s32 pm_qos_read_value(struct pm_qos_constraints *c); int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node, enum pm_qos_req_action action, int value); bool pm_qos_update_flags(struct pm_qos_flags *pqf, struct pm_qos_flags_request *req, enum pm_qos_req_action action, s32 val); + 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 *req); - -int pm_qos_request(int pm_qos_class); +s32 pm_qos_request(int pm_qos_class); int pm_qos_request_active(struct pm_qos_request *req); -s32 pm_qos_read_value(struct pm_qos_constraints *c); #ifdef CONFIG_PM enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask); diff --git a/kernel/power/qos.c b/kernel/power/qos.c index afac7010e0f2..7bb55aca03bb 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -235,11 +235,10 @@ static struct pm_qos_constraints cpu_latency_constraints = { * * This function returns the current target value. */ -int pm_qos_request(int pm_qos_class) +s32 pm_qos_request(int pm_qos_class) { return pm_qos_read_value(&cpu_latency_constraints); } -EXPORT_SYMBOL_GPL(pm_qos_request); int pm_qos_request_active(struct pm_qos_request *req) { -- cgit v1.2.3 From 67b06ba01857ed077e1a66bfa139156e7c68bab2 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 12 Feb 2020 00:35:04 +0100 Subject: PM: QoS: Drop PM_QOS_CPU_DMA_LATENCY and rename related functions Drop the PM QoS classes enum including PM_QOS_CPU_DMA_LATENCY, drop the wrappers around pm_qos_request(), pm_qos_request_active(), and pm_qos_add/update/remove_request() introduced previously, rename these functions, respectively, to cpu_latency_qos_limit(), cpu_latency_qos_request_active(), and cpu_latency_qos_add/update/remove_request(), and update their kerneldoc comments. [While at it, drop some useless comments from these functions.] No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- include/linux/pm_qos.h | 47 +++--------------------- kernel/power/qos.c | 98 +++++++++++++++++++++++++------------------------- 2 files changed, 54 insertions(+), 91 deletions(-) (limited to 'kernel') diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 63d39e66f95d..e0ca4d780457 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -9,14 +9,6 @@ #include #include -enum { - PM_QOS_RESERVED = 0, - PM_QOS_CPU_DMA_LATENCY, - - /* insert new class ID */ - PM_QOS_NUM_CLASSES, -}; - enum pm_qos_flags_status { PM_QOS_FLAGS_UNDEFINED = -1, PM_QOS_FLAGS_NONE, @@ -144,40 +136,11 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf, struct pm_qos_flags_request *req, enum pm_qos_req_action action, s32 val); -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 *req); -s32 pm_qos_request(int pm_qos_class); -int pm_qos_request_active(struct pm_qos_request *req); - -static inline void cpu_latency_qos_add_request(struct pm_qos_request *req, - s32 value) -{ - pm_qos_add_request(req, PM_QOS_CPU_DMA_LATENCY, value); -} - -static inline void cpu_latency_qos_update_request(struct pm_qos_request *req, - s32 new_value) -{ - pm_qos_update_request(req, new_value); -} - -static inline void cpu_latency_qos_remove_request(struct pm_qos_request *req) -{ - pm_qos_remove_request(req); -} - -static inline bool cpu_latency_qos_request_active(struct pm_qos_request *req) -{ - return pm_qos_request_active(req); -} - -static inline s32 cpu_latency_qos_limit(void) -{ - return pm_qos_request(PM_QOS_CPU_DMA_LATENCY); -} +s32 cpu_latency_qos_limit(void); +bool cpu_latency_qos_request_active(struct pm_qos_request *req); +void cpu_latency_qos_add_request(struct pm_qos_request *req, s32 value); +void cpu_latency_qos_update_request(struct pm_qos_request *req, s32 new_value); +void cpu_latency_qos_remove_request(struct pm_qos_request *req); #ifdef CONFIG_PM enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask); diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 7bb55aca03bb..7374c76f409a 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -230,21 +230,25 @@ static struct pm_qos_constraints cpu_latency_constraints = { }; /** - * pm_qos_request - returns current system wide qos expectation - * @pm_qos_class: Ignored. - * - * This function returns the current target value. + * cpu_latency_qos_limit - Return current system-wide CPU latency QoS limit. */ -s32 pm_qos_request(int pm_qos_class) +s32 cpu_latency_qos_limit(void) { return pm_qos_read_value(&cpu_latency_constraints); } -int pm_qos_request_active(struct pm_qos_request *req) +/** + * cpu_latency_qos_request_active - Check the given PM QoS request. + * @req: PM QoS request to check. + * + * Return: 'true' if @req has been added to the CPU latency QoS list, 'false' + * otherwise. + */ +bool cpu_latency_qos_request_active(struct pm_qos_request *req) { return req->qos == &cpu_latency_constraints; } -EXPORT_SYMBOL_GPL(pm_qos_request_active); +EXPORT_SYMBOL_GPL(cpu_latency_qos_request_active); static void cpu_latency_qos_apply(struct pm_qos_request *req, enum pm_qos_req_action action, s32 value) @@ -255,25 +259,24 @@ static void cpu_latency_qos_apply(struct pm_qos_request *req, } /** - * pm_qos_add_request - inserts new qos request into the list - * @req: pointer to a preallocated handle - * @pm_qos_class: Ignored. - * @value: defines the qos request + * cpu_latency_qos_add_request - Add new CPU latency QoS request. + * @req: Pointer to a preallocated handle. + * @value: Requested constraint value. + * + * Use @value to initialize the request handle pointed to by @req, insert it as + * a new entry to the CPU latency QoS list and recompute the effective QoS + * constraint for that list. * - * This function inserts a new entry in the PM_QOS_CPU_DMA_LATENCY list of - * requested QoS performance characteristics. It recomputes the aggregate QoS - * expectations for the PM_QOS_CPU_DMA_LATENCY list and initializes the @req - * handle. Caller needs to save this handle for later use in updates and - * removal. + * Callers need to save the handle for later use in updates and removal of the + * QoS request represented by it. */ -void pm_qos_add_request(struct pm_qos_request *req, - int pm_qos_class, s32 value) +void cpu_latency_qos_add_request(struct pm_qos_request *req, s32 value) { - if (!req) /*guard against callers passing in null */ + if (!req) return; - if (pm_qos_request_active(req)) { - WARN(1, KERN_ERR "pm_qos_add_request() called for already added request\n"); + if (cpu_latency_qos_request_active(req)) { + WARN(1, KERN_ERR "%s called for already added request\n", __func__); return; } @@ -282,25 +285,24 @@ void pm_qos_add_request(struct pm_qos_request *req, req->qos = &cpu_latency_constraints; cpu_latency_qos_apply(req, PM_QOS_ADD_REQ, value); } -EXPORT_SYMBOL_GPL(pm_qos_add_request); +EXPORT_SYMBOL_GPL(cpu_latency_qos_add_request); /** - * pm_qos_update_request - modifies an existing qos request - * @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_CPU_DMA_LATENCY list along - * with updating the target PM_QOS_CPU_DMA_LATENCY value. + * cpu_latency_qos_update_request - Modify existing CPU latency QoS request. + * @req : QoS request to update. + * @new_value: New requested constraint value. * - * Attempts are made to make this code callable on hot code paths. + * Use @new_value to update the QoS request represented by @req in the CPU + * latency QoS list along with updating the effective constraint value for that + * list. */ -void pm_qos_update_request(struct pm_qos_request *req, s32 new_value) +void cpu_latency_qos_update_request(struct pm_qos_request *req, s32 new_value) { - if (!req) /*guard against callers passing in null */ + if (!req) return; - if (!pm_qos_request_active(req)) { - WARN(1, KERN_ERR "pm_qos_update_request() called for unknown object\n"); + if (!cpu_latency_qos_request_active(req)) { + WARN(1, KERN_ERR "%s called for unknown object\n", __func__); return; } @@ -311,24 +313,22 @@ void pm_qos_update_request(struct pm_qos_request *req, s32 new_value) cpu_latency_qos_apply(req, PM_QOS_UPDATE_REQ, new_value); } -EXPORT_SYMBOL_GPL(pm_qos_update_request); +EXPORT_SYMBOL_GPL(cpu_latency_qos_update_request); /** - * pm_qos_remove_request - modifies an existing qos request - * @req: handle to request list element + * cpu_latency_qos_remove_request - Remove existing CPU latency QoS request. + * @req: QoS request to remove. * - * Will remove pm qos request from the list of constraints and - * recompute the current target value for PM_QOS_CPU_DMA_LATENCY. Call this - * on slow code paths. + * Remove the CPU latency QoS request represented by @req from the CPU latency + * QoS list along with updating the effective constraint value for that list. */ -void pm_qos_remove_request(struct pm_qos_request *req) +void cpu_latency_qos_remove_request(struct pm_qos_request *req) { - if (!req) /*guard against callers passing in null */ + if (!req) return; - /* silent return to keep pcm code cleaner */ - if (!pm_qos_request_active(req)) { - WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown object\n"); + if (!cpu_latency_qos_request_active(req)) { + WARN(1, KERN_ERR "%s called for unknown object\n", __func__); return; } @@ -337,7 +337,7 @@ void pm_qos_remove_request(struct pm_qos_request *req) cpu_latency_qos_apply(req, PM_QOS_REMOVE_REQ, PM_QOS_DEFAULT_VALUE); memset(req, 0, sizeof(*req)); } -EXPORT_SYMBOL_GPL(pm_qos_remove_request); +EXPORT_SYMBOL_GPL(cpu_latency_qos_remove_request); /* User space interface to the CPU latency QoS via misc device. */ @@ -349,7 +349,7 @@ static int cpu_latency_qos_open(struct inode *inode, struct file *filp) if (!req) return -ENOMEM; - pm_qos_add_request(req, PM_QOS_CPU_DMA_LATENCY, PM_QOS_DEFAULT_VALUE); + cpu_latency_qos_add_request(req, PM_QOS_DEFAULT_VALUE); filp->private_data = req; return 0; @@ -361,7 +361,7 @@ static int cpu_latency_qos_release(struct inode *inode, struct file *filp) filp->private_data = NULL; - pm_qos_remove_request(req); + cpu_latency_qos_remove_request(req); kfree(req); return 0; @@ -374,7 +374,7 @@ static ssize_t cpu_latency_qos_read(struct file *filp, char __user *buf, unsigned long flags; s32 value; - if (!req || !pm_qos_request_active(req)) + if (!req || !cpu_latency_qos_request_active(req)) return -EINVAL; spin_lock_irqsave(&pm_qos_lock, flags); @@ -400,7 +400,7 @@ static ssize_t cpu_latency_qos_write(struct file *filp, const char __user *buf, return ret; } - pm_qos_update_request(filp->private_data, value); + cpu_latency_qos_update_request(filp->private_data, value); return count; } -- cgit v1.2.3 From fe52de36dc5d60960230cabec88c357113d9c32a Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 12 Feb 2020 00:35:39 +0100 Subject: PM: QoS: Update file information comments Update the file information comments in include/linux/pm_qos.h and kernel/power/qos.c by adding titles along with copyright and authors information to them and changing the qos.c description to better reflect its contents (outdated information is dropped from it in particular). Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- include/linux/pm_qos.h | 15 +++++++++++---- kernel/power/qos.c | 34 ++++++++++++---------------------- 2 files changed, 23 insertions(+), 26 deletions(-) (limited to 'kernel') diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index e0ca4d780457..df065db3f57a 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -1,10 +1,17 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _LINUX_PM_QOS_H -#define _LINUX_PM_QOS_H -/* interface for the pm_qos_power infrastructure of the linux kernel. +/* + * Definitions related to Power Management Quality of Service (PM QoS). + * + * Copyright (C) 2020 Intel Corporation * - * Mark Gross + * Authors: + * Mark Gross + * Rafael J. Wysocki */ + +#ifndef _LINUX_PM_QOS_H +#define _LINUX_PM_QOS_H + #include #include #include diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 7374c76f409a..ef73573db43d 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -1,31 +1,21 @@ // SPDX-License-Identifier: GPL-2.0-only /* - * This module exposes the interface to kernel space for specifying - * QoS dependencies. It provides infrastructure for registration of: + * Power Management Quality of Service (PM QoS) support base. * - * Dependents on a QoS value : register requests - * Watchers of QoS value : get notified when target QoS value changes + * Copyright (C) 2020 Intel Corporation * - * 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. + * Authors: + * Mark Gross + * Rafael J. Wysocki * - * 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) + * Provided here is an interface for specifying PM QoS dependencies. It allows + * entities depending on QoS constraints to register their requests which are + * aggregated as appropriate to produce effective constraints (target values) + * that can be monitored by entities needing to respect them, either by polling + * or through a built-in notification mechanism. * - * 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 + * In addition to the basic functionality, more specific interfaces for managing + * global CPU latency QoS requests and frequency QoS requests are provided. */ /*#define DEBUG*/ -- cgit v1.2.3 From 814d51f8889bc4afa75f647eeffd5ff0a5620e8d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 12 Feb 2020 00:37:11 +0100 Subject: PM: QoS: Make CPU latency QoS depend on CONFIG_CPU_IDLE Because cpuidle is the only user of the effective constraint coming from the CPU latency QoS, add #ifdef CONFIG_CPU_IDLE around that code to avoid building it unnecessarily. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Amit Kucheria Tested-by: Amit Kucheria --- include/linux/pm_qos.h | 13 +++++++++++++ kernel/power/qos.c | 2 ++ 2 files changed, 15 insertions(+) (limited to 'kernel') diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index df065db3f57a..4a69d4af3ff8 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -143,11 +143,24 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf, struct pm_qos_flags_request *req, enum pm_qos_req_action action, s32 val); +#ifdef CONFIG_CPU_IDLE s32 cpu_latency_qos_limit(void); bool cpu_latency_qos_request_active(struct pm_qos_request *req); void cpu_latency_qos_add_request(struct pm_qos_request *req, s32 value); void cpu_latency_qos_update_request(struct pm_qos_request *req, s32 new_value); void cpu_latency_qos_remove_request(struct pm_qos_request *req); +#else +static inline s32 cpu_latency_qos_limit(void) { return INT_MAX; } +static inline bool cpu_latency_qos_request_active(struct pm_qos_request *req) +{ + return false; +} +static inline void cpu_latency_qos_add_request(struct pm_qos_request *req, + s32 value) {} +static inline void cpu_latency_qos_update_request(struct pm_qos_request *req, + s32 new_value) {} +static inline void cpu_latency_qos_remove_request(struct pm_qos_request *req) {} +#endif #ifdef CONFIG_PM enum pm_qos_flags_status __dev_pm_qos_flags(struct device *dev, s32 mask); diff --git a/kernel/power/qos.c b/kernel/power/qos.c index ef73573db43d..32927682bcc4 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -209,6 +209,7 @@ bool pm_qos_update_flags(struct pm_qos_flags *pqf, return prev_value != curr_value; } +#ifdef CONFIG_CPU_IDLE /* Definitions related to the CPU latency QoS. */ static struct pm_qos_constraints cpu_latency_constraints = { @@ -421,6 +422,7 @@ static int __init cpu_latency_qos_init(void) return ret; } late_initcall(cpu_latency_qos_init); +#endif /* CONFIG_CPU_IDLE */ /* Definitions related to the frequency QoS below. */ -- cgit v1.2.3 From a534e924c58d2e7c07509521e87d059dd029dca1 Mon Sep 17 00:00:00 2001 From: Qian Cai Date: Tue, 25 Feb 2020 20:58:13 -0500 Subject: PM: QoS: annotate data races in pm_qos_*_value() The target_value field in struct pm_qos_constraints is used for lockless access to the effective constraint value of a given QoS list, so the readers of it cannot expect it to always reflect the most recent effective constraint value. However, they can and do expect it to be equal to a valid effective constraint value computed at a certain time in the past (event though it may not be the most recent one), so add READ|WRITE_ONCE() annotations around the target_value accesses to prevent the compiler from possibly causing that expectation to be unmet by generating code in an exceptionally convoluted way. Signed-off-by: Qian Cai [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki --- kernel/power/qos.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/power/qos.c b/kernel/power/qos.c index 32927682bcc4..db0bed2cae26 100644 --- a/kernel/power/qos.c +++ b/kernel/power/qos.c @@ -52,7 +52,7 @@ static DEFINE_SPINLOCK(pm_qos_lock); */ s32 pm_qos_read_value(struct pm_qos_constraints *c) { - return c->target_value; + return READ_ONCE(c->target_value); } static int pm_qos_get_value(struct pm_qos_constraints *c) @@ -75,7 +75,7 @@ static int pm_qos_get_value(struct pm_qos_constraints *c) static void pm_qos_set_value(struct pm_qos_constraints *c, s32 value) { - c->target_value = value; + WRITE_ONCE(c->target_value, value); } /** -- cgit v1.2.3