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authorRafael J. Wysocki <rjw@sisk.pl>2011-10-07 23:17:07 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2011-10-07 23:17:07 +0200
commit9696cc90071e3660ec02a3728acdedb68afdce4c (patch)
tree99783d31dd42262c29346c92760f7896c3d81cb6 /kernel
parentc28b56b1d46b1bbb1be33c8f2632a88b0de1ef68 (diff)
parente3cba3243eb853a052613c804dea033bc4c9cf2d (diff)
Merge branch 'pm-qos' into pm-for-linus
* pm-qos: PM / QoS: Update Documentation for the pm_qos and dev_pm_qos frameworks PM / QoS: Add function dev_pm_qos_read_value() (v3) PM QoS: Add global notification mechanism for device constraints PM QoS: Implement per-device PM QoS constraints PM QoS: Generalize and export constraints management code PM QoS: Reorganize data structs PM QoS: Code reorganization PM QoS: Minor clean-ups PM QoS: Move and rename the implementation files
Diffstat (limited to 'kernel')
-rw-r--r--kernel/Makefile2
-rw-r--r--kernel/power/Makefile2
-rw-r--r--kernel/power/qos.c (renamed from kernel/pm_qos_params.c)273
3 files changed, 143 insertions, 134 deletions
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/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/pm_qos_params.c b/kernel/power/qos.c
index 37f05d0f0793..1c1797dd1d1d 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/power/qos.c
@@ -29,7 +29,7 @@
/*#define DEBUG*/
-#include <linux/pm_qos_params.h>
+#include <linux/pm_qos.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
@@ -45,62 +45,57 @@
#include <linux/uaccess.h>
/*
- * 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
*/
-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 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 = {
- .requests = PLIST_HEAD_INIT(cpu_dma_pm_qos.requests),
- .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 = {
- .requests = PLIST_HEAD_INIT(network_lat_pm_qos.requests),
- .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 = {
- .requests = PLIST_HEAD_INIT(network_throughput_pm_qos.requests),
- .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",
};
@@ -127,17 +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->requests))
- return o->default_value;
+ if (plist_head_empty(&c->list))
+ return c->default_value;
- switch (o->type) {
+ switch (c->type) {
case PM_QOS_MIN:
- return plist_first(&o->requests)->prio;
+ return plist_first(&c->list)->prio;
case PM_QOS_MAX:
- return plist_last(&o->requests)->prio;
+ return plist_last(&c->list)->prio;
default:
/* runtime check for not using enum */
@@ -145,69 +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)
+s32 pm_qos_read_value(struct pm_qos_constraints *c)
{
- return o->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->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->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);
+ 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->notifiers,
+ if (prev_value != curr_value) {
+ blocking_notifier_call_chain(c->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;
+ } else {
+ return 0;
}
- return -1;
}
/**
@@ -218,11 +217,11 @@ static int find_pm_qos_object_by_minor(int minor)
*/
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);
-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;
}
@@ -230,40 +229,36 @@ 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 (!req) /*guard against callers passing in null */
+ return;
- 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;
}
- 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);
+ req->pm_qos_class = pm_qos_class;
+ 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);
/**
* 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 +266,47 @@ 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];
-
- 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 (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);
/**
* 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) /*guard against callers passing in 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));
+ 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);
@@ -337,7 +323,8 @@ 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;
}
@@ -356,19 +343,43 @@ 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;
}
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;
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 +394,7 @@ 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);
@@ -398,17 +409,15 @@ 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];
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));
@@ -418,7 +427,7 @@ 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 +458,8 @@ 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;
}