1 files changed, 23 insertions, 25 deletions

diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index 0afe32be4c85..dfdec524d1b7 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -24,11 +24,12 @@
  * requirement 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 mgross@linux.intel.com
+ * Mark Gross <mgross@linux.intel.com>
  */
 
 #include <linux/pm_qos_params.h>
 #include <linux/sched.h>
+#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
 #include <linux/time.h>
@@ -42,7 +43,7 @@
 #include <linux/uaccess.h>
 
 /*
- * locking rule: all changes to target_value or requirements or notifiers lists
+ * locking rule: all changes to requirements 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
  */
@@ -65,7 +66,7 @@ struct pm_qos_object {
         struct miscdevice pm_qos_power_miscdev;
         char *name;
         s32 default_value;
-        s32 target_value;
+        atomic_t target_value;
         s32 (*comparitor)(s32, s32);
 };
 
@@ -76,7 +77,7 @@ static struct pm_qos_object cpu_dma_pm_qos = {
         .notifiers = &cpu_dma_lat_notifier,
         .name = "cpu_dma_latency",
         .default_value = 2000 * USEC_PER_SEC,
-        .target_value = 2000 * USEC_PER_SEC,
+        .target_value = ATOMIC_INIT(2000 * USEC_PER_SEC),
         .comparitor = min_compare
 };
 
@@ -86,7 +87,7 @@ static struct pm_qos_object network_lat_pm_qos = {
         .notifiers = &network_lat_notifier,
         .name = "network_latency",
         .default_value = 2000 * USEC_PER_SEC,
-        .target_value = 2000 * USEC_PER_SEC,
+        .target_value = ATOMIC_INIT(2000 * USEC_PER_SEC),
         .comparitor = min_compare
 };
 
@@ -98,7 +99,7 @@ static struct pm_qos_object network_throughput_pm_qos = {
         .notifiers = &network_throughput_notifier,
         .name = "network_throughput",
         .default_value = 0,
-        .target_value = 0,
+        .target_value = ATOMIC_INIT(0),
         .comparitor = max_compare
 };
 
@@ -149,11 +150,11 @@ static void update_target(int target)
                 extreme_value = pm_qos_array[target]->comparitor(
                                 extreme_value, node->value);
         }
-        if (pm_qos_array[target]->target_value != extreme_value) {
+        if (atomic_read(&pm_qos_array[target]->target_value) != extreme_value) {
                 call_notifier = 1;
-                pm_qos_array[target]->target_value = extreme_value;
+                atomic_set(&pm_qos_array[target]->target_value, extreme_value);
                 pr_debug(KERN_ERR "new target for qos %d is %d\n", target,
-                        pm_qos_array[target]->target_value);
+                        atomic_read(&pm_qos_array[target]->target_value));
         }
         spin_unlock_irqrestore(&pm_qos_lock, flags);
 
@@ -192,14 +193,7 @@ static int find_pm_qos_object_by_minor(int minor)
  */
 int pm_qos_requirement(int pm_qos_class)
 {
-        int ret_val;
-        unsigned long flags;
-
-        spin_lock_irqsave(&pm_qos_lock, flags);
-        ret_val = pm_qos_array[pm_qos_class]->target_value;
-        spin_unlock_irqrestore(&pm_qos_lock, flags);
-
-        return ret_val;
+        return atomic_read(&pm_qos_array[pm_qos_class]->target_value);
 }
 EXPORT_SYMBOL_GPL(pm_qos_requirement);
 
@@ -210,8 +204,8 @@ EXPORT_SYMBOL_GPL(pm_qos_requirement);
  * @value: defines the qos request
  *
  * This function inserts a new entry in the pm_qos_class list of requested qos
- * performance charactoistics.  It recomputes the agregate QoS expectations for
- * the pm_qos_class of parrameters.
+ * performance characteristics.  It recomputes the aggregate QoS expectations
+ * for the pm_qos_class of parameters.
  */
 int pm_qos_add_requirement(int pm_qos_class, char *name, s32 value)
 {
@@ -249,10 +243,10 @@ EXPORT_SYMBOL_GPL(pm_qos_add_requirement);
  * @name: identifies the request
  * @value: defines the qos request
  *
- * Updates an existing qos requierement for the pm_qos_class of parameters along
+ * Updates an existing qos requirement for the pm_qos_class of parameters along
  * with updating the target pm_qos_class value.
  *
- * If the named request isn't in the lest then no change is made.
+ * If the named request isn't in the list then no change is made.
  */
 int pm_qos_update_requirement(int pm_qos_class, char *name, s32 new_value)
 {
@@ -286,7 +280,7 @@ EXPORT_SYMBOL_GPL(pm_qos_update_requirement);
  * @pm_qos_class: identifies which list of qos request to us
  * @name: identifies the request
  *
- * Will remove named qos request from pm_qos_class list of parrameters and
+ * Will remove named qos request from pm_qos_class list of parameters and
  * recompute the current target value for the pm_qos_class.
  */
 void pm_qos_remove_requirement(int pm_qos_class, char *name)
@@ -318,7 +312,7 @@ EXPORT_SYMBOL_GPL(pm_qos_remove_requirement);
  * @notifier: notifier block managed by caller.
  *
  * will register the notifier into a notification chain that gets called
- * uppon changes to the pm_qos_class target value.
+ * upon changes to the pm_qos_class target value.
  */
  int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier)
 {
@@ -337,7 +331,7 @@ EXPORT_SYMBOL_GPL(pm_qos_add_notifier);
  * @notifier: notifier block to be removed.
  *
  * will remove the notifier from the notification chain that gets called
- * uppon changes to the pm_qos_class target value.
+ * upon changes to the pm_qos_class target value.
  */
 int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
 {
@@ -358,15 +352,19 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp)
         int ret;
         long pm_qos_class;
 
+        lock_kernel();
         pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
         if (pm_qos_class >= 0) {
                 filp->private_data = (void *)pm_qos_class;
                 sprintf(name, "process_%d", current->pid);
                 ret = pm_qos_add_requirement(pm_qos_class, name,
                                         PM_QOS_DEFAULT_VALUE);
-                if (ret >= 0)
+                if (ret >= 0) {
+                        unlock_kernel();
                         return 0;
+                }
         }
+        unlock_kernel();
 
         return -EPERM;
 }