pm_qos: Get rid of the allocation in pm_qos_add_request()

All current users of pm_qos_add_request() have the ability to supply
the memory required by the pm_qos routines, so make them do this and
eliminate the kmalloc() with pm_qos_add_request().  This has the
double benefit of making the call never fail and allowing it to be
called from atomic context.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: mark gross <markgross@thegnar.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

1 files changed, 40 insertions, 27 deletions

diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index db8e51d7f392..996a4dec5f96 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -30,7 +30,6 @@
 /*#define DEBUG*/
 
 #include <linux/pm_qos_params.h>
-#include <linux/plist.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
@@ -49,11 +48,6 @@
  * 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_request_list {
-        struct plist_node list;
-        int pm_qos_class;
-};
-
 enum pm_qos_type {
         PM_QOS_MAX,             /* return the largest value */
         PM_QOS_MIN              /* return the smallest value */
@@ -210,6 +204,12 @@ int pm_qos_request(int pm_qos_class)
 }
 EXPORT_SYMBOL_GPL(pm_qos_request);
 
+int pm_qos_request_active(struct pm_qos_request_list *req)
+{
+        return req->pm_qos_class != 0;
+}
+EXPORT_SYMBOL_GPL(pm_qos_request_active);
+
 /**
  * pm_qos_add_request - inserts new qos request into the list
  * @pm_qos_class: identifies which list of qos request to us
@@ -221,25 +221,23 @@ EXPORT_SYMBOL_GPL(pm_qos_request);
  * element as a handle for use in updating and removal.  Call needs to save
  * this handle for later use.
  */
-struct pm_qos_request_list *pm_qos_add_request(int pm_qos_class, s32 value)
+void pm_qos_add_request(struct pm_qos_request_list *dep,
+                        int pm_qos_class, s32 value)
 {
-        struct pm_qos_request_list *dep;
-
-        dep = kzalloc(sizeof(struct pm_qos_request_list), GFP_KERNEL);
-        if (dep) {
-                struct pm_qos_object *o =  pm_qos_array[pm_qos_class];
-                int new_value;
-
-                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);
-        }
+        struct pm_qos_object *o =  pm_qos_array[pm_qos_class];
+        int new_value;
 
-        return dep;
+        if (pm_qos_request_active(dep)) {
+                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);
 }
 EXPORT_SYMBOL_GPL(pm_qos_add_request);
 
@@ -262,6 +260,11 @@ void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req,
         if (!pm_qos_req) /*guard against callers passing in null */
                 return;
 
+        if (!pm_qos_request_active(pm_qos_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)
@@ -290,9 +293,14 @@ void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req)
                 return;
                 /* silent return to keep pcm code cleaner */
 
+        if (!pm_qos_request_active(pm_qos_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);
-        kfree(pm_qos_req);
+        memset(pm_qos_req, 0, sizeof(*pm_qos_req));
 }
 EXPORT_SYMBOL_GPL(pm_qos_remove_request);
 
@@ -340,8 +348,12 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp)
 
         pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
         if (pm_qos_class >= 0) {
-                filp->private_data = (void *) pm_qos_add_request(pm_qos_class,
-                                PM_QOS_DEFAULT_VALUE);
+                struct pm_qos_request_list *req = kzalloc(GFP_KERNEL, sizeof(*req));
+                if (!req)
+                        return -ENOMEM;
+
+                pm_qos_add_request(req, pm_qos_class, PM_QOS_DEFAULT_VALUE);
+                filp->private_data = req;
 
                 if (filp->private_data)
                         return 0;
@@ -353,8 +365,9 @@ static int pm_qos_power_release(struct inode *inode, struct file *filp)
 {
         struct pm_qos_request_list *req;
 
-        req = (struct pm_qos_request_list *)filp->private_data;
+        req = filp->private_data;
         pm_qos_remove_request(req);
+        kfree(req);
 
         return 0;
 }