* . a system-wide notification callback using the dev_pm_qos_*_global_notifier
* API. The notification chain data is stored in a static variable.
*
- * Notes about the per-device constraint data struct allocation:
- * . The per-device constraints data struct ptr is stored into the device
+ * Note about the per-device constraint data struct allocation:
+ * . The per-device constraints data struct ptr is tored into the device
* dev_pm_info.
* . To minimize the data usage by the per-device constraints, the data struct
- * is only allocated at the first call to dev_pm_qos_add_request.
+ * is only allocated at the first call to dev_pm_qos_add_request.
* . The data is later free'd when the device is removed from the system.
- *
- * Notes about locking:
- * . The dev->power.lock lock protects the constraints list
- * (dev->power.constraints) allocation and free, as triggered by the
- * driver core code at device insertion and removal,
- * . A global lock dev_pm_qos_lock protects the constraints list entries
- * from any modification and the notifiers registration and unregistration.
- * . For both locks a spinlock is needed since this code can be called from
- * interrupt context or spinlock protected context.
+ * . A global mutex protects the constraints users from the data being
+ * allocated and free'd.
*/
#include <linux/pm_qos.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/device.h>
+#include <linux/mutex.h>
#include <linux/export.h>
#include "power.h"
-static DEFINE_SPINLOCK(dev_pm_qos_lock);
+static DEFINE_MUTEX(dev_pm_qos_mtx);
static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers);
* @dev: device to allocate data for
*
* Called at the first call to add_request, for constraint data allocation
- * Must be called with the dev_pm_qos_lock lock held
+ * Must be called with the dev_pm_qos_mtx mutex held
*/
static int dev_pm_qos_constraints_allocate(struct device *dev)
{
struct pm_qos_constraints *c;
struct blocking_notifier_head *n;
- unsigned long flags;
- c = kzalloc(sizeof(*c), GFP_ATOMIC);
+ c = kzalloc(sizeof(*c), GFP_KERNEL);
if (!c)
return -ENOMEM;
- n = kzalloc(sizeof(*n), GFP_ATOMIC);
+ n = kzalloc(sizeof(*n), GFP_KERNEL);
if (!n) {
kfree(c);
return -ENOMEM;
c->type = PM_QOS_MIN;
c->notifiers = n;
- spin_lock_irqsave(&dev->power.lock, flags);
+ spin_lock_irq(&dev->power.lock);
dev->power.constraints = c;
- spin_unlock_irqrestore(&dev->power.lock, flags);
+ spin_unlock_irq(&dev->power.lock);
return 0;
}
*/
void dev_pm_qos_constraints_init(struct device *dev)
{
- unsigned long flags;
-
- spin_lock_irqsave(&dev_pm_qos_lock, flags);
+ mutex_lock(&dev_pm_qos_mtx);
dev->power.constraints = NULL;
dev->power.power_state = PMSG_ON;
- spin_unlock_irqrestore(&dev_pm_qos_lock, flags);
+ mutex_unlock(&dev_pm_qos_mtx);
}
/**
{
struct dev_pm_qos_request *req, *tmp;
struct pm_qos_constraints *c;
- unsigned long flags;
/*
* If the device's PM QoS resume latency limit has been exposed to user
*/
dev_pm_qos_hide_latency_limit(dev);
- spin_lock_irqsave(&dev_pm_qos_lock, flags);
+ mutex_lock(&dev_pm_qos_mtx);
dev->power.power_state = PMSG_INVALID;
c = dev->power.constraints;
kfree(c);
out:
- spin_unlock_irqrestore(&dev_pm_qos_lock, flags);
+ mutex_unlock(&dev_pm_qos_mtx);
}
/**
s32 value)
{
int ret = 0;
- unsigned long flags;
if (!dev || !req) /*guard against callers passing in null */
return -EINVAL;
req->dev = dev;
- spin_lock_irqsave(&dev_pm_qos_lock, flags);
+ mutex_lock(&dev_pm_qos_mtx);
if (!dev->power.constraints) {
if (dev->power.power_state.event == PM_EVENT_INVALID) {
ret = apply_constraint(req, PM_QOS_ADD_REQ, value);
out:
- spin_unlock_irqrestore(&dev_pm_qos_lock, flags);
+ mutex_unlock(&dev_pm_qos_mtx);
return ret;
}
s32 new_value)
{
int ret = 0;
- unsigned long flags;
if (!req) /*guard against callers passing in null */
return -EINVAL;
"%s() called for unknown object\n", __func__))
return -EINVAL;
- spin_lock_irqsave(&dev_pm_qos_lock, flags);
+ mutex_lock(&dev_pm_qos_mtx);
if (req->dev->power.constraints) {
if (new_value != req->node.prio)
ret = -ENODEV;
}
- spin_unlock_irqrestore(&dev_pm_qos_lock, flags);
+ mutex_unlock(&dev_pm_qos_mtx);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_update_request);
int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
{
int ret = 0;
- unsigned long flags;
if (!req) /*guard against callers passing in null */
return -EINVAL;
"%s() called for unknown object\n", __func__))
return -EINVAL;
- spin_lock_irqsave(&dev_pm_qos_lock, flags);
+ mutex_lock(&dev_pm_qos_mtx);
if (req->dev->power.constraints) {
ret = apply_constraint(req, PM_QOS_REMOVE_REQ,
ret = -ENODEV;
}
- spin_unlock_irqrestore(&dev_pm_qos_lock, flags);
+ mutex_unlock(&dev_pm_qos_mtx);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_remove_request);
int dev_pm_qos_add_notifier(struct device *dev, struct notifier_block *notifier)
{
int ret = 0;
- unsigned long flags;
- spin_lock_irqsave(&dev_pm_qos_lock, flags);
+ mutex_lock(&dev_pm_qos_mtx);
if (!dev->power.constraints)
ret = dev->power.power_state.event != PM_EVENT_INVALID ?
ret = blocking_notifier_chain_register(
dev->power.constraints->notifiers, notifier);
- spin_unlock_irqrestore(&dev_pm_qos_lock, flags);
+ mutex_unlock(&dev_pm_qos_mtx);
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_add_notifier);
struct notifier_block *notifier)
{
int retval = 0;
- unsigned long flags;
- spin_lock_irqsave(&dev_pm_qos_lock, flags);
+ mutex_lock(&dev_pm_qos_mtx);
/* Silently return if the constraints object is not present. */
if (dev->power.constraints)
dev->power.constraints->notifiers,
notifier);
- spin_unlock_irqrestore(&dev_pm_qos_lock, flags);
+ mutex_unlock(&dev_pm_qos_mtx);
return retval;
}
EXPORT_SYMBOL_GPL(dev_pm_qos_remove_notifier);
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