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>

8 files changed, 74 insertions, 61 deletions

diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c
index 57a7e41..9f13b66 100644
--- a/drivers/net/e1000e/netdev.c
+++ b/drivers/net/e1000e/netdev.c
@@ -2901,10 +2901,10 @@ static void e1000_configure_rx(struct e1000_adapter *adapter)
 			 * dropped transactions.
 			 */
 			pm_qos_update_request(
-				adapter->netdev->pm_qos_req, 55);
+				&adapter->netdev->pm_qos_req, 55);
 		} else {
 			pm_qos_update_request(
-				adapter->netdev->pm_qos_req,
+				&adapter->netdev->pm_qos_req,
 				PM_QOS_DEFAULT_VALUE);
 		}
 	}
@@ -3196,9 +3196,9 @@ int e1000e_up(struct e1000_adapter *adapter)
 
 	/* DMA latency requirement to workaround early-receive/jumbo issue */
 	if (adapter->flags & FLAG_HAS_ERT)
-		adapter->netdev->pm_qos_req =
-			pm_qos_add_request(PM_QOS_CPU_DMA_LATENCY,
-				       PM_QOS_DEFAULT_VALUE);
+		pm_qos_add_request(&adapter->netdev->pm_qos_req,
+				   PM_QOS_CPU_DMA_LATENCY,
+				   PM_QOS_DEFAULT_VALUE);
 
 	/* hardware has been reset, we need to reload some things */
 	e1000_configure(adapter);
@@ -3263,11 +3263,8 @@ void e1000e_down(struct e1000_adapter *adapter)
 	e1000_clean_tx_ring(adapter);
 	e1000_clean_rx_ring(adapter);
 
-	if (adapter->flags & FLAG_HAS_ERT) {
-		pm_qos_remove_request(
-			      adapter->netdev->pm_qos_req);
-		adapter->netdev->pm_qos_req = NULL;
-	}
+	if (adapter->flags & FLAG_HAS_ERT)
+		pm_qos_remove_request(&adapter->netdev->pm_qos_req);
 
 	/*
 	 * TODO: for power management, we could drop the link and
diff --git a/drivers/net/igbvf/netdev.c b/drivers/net/igbvf/netdev.c
index 5e2b2a8..add6197 100644
--- a/drivers/net/igbvf/netdev.c
+++ b/drivers/net/igbvf/netdev.c
@@ -48,7 +48,7 @@
 #define DRV_VERSION "1.0.0-k0"
 char igbvf_driver_name[] = "igbvf";
 const char igbvf_driver_version[] = DRV_VERSION;
-struct pm_qos_request_list *igbvf_driver_pm_qos_req;
+static struct pm_qos_request_list igbvf_driver_pm_qos_req;
 static const char igbvf_driver_string[] =
 				"Intel(R) Virtual Function Network Driver";
 static const char igbvf_copyright[] = "Copyright (c) 2009 Intel Corporation.";
@@ -2902,8 +2902,8 @@ static int __init igbvf_init_module(void)
 	printk(KERN_INFO "%s\n", igbvf_copyright);
 
 	ret = pci_register_driver(&igbvf_driver);
-	igbvf_driver_pm_qos_req = pm_qos_add_request(PM_QOS_CPU_DMA_LATENCY,
-	                       PM_QOS_DEFAULT_VALUE);
+	pm_qos_add_request(&igbvf_driver_pm_qos_req, PM_QOS_CPU_DMA_LATENCY,
+			   PM_QOS_DEFAULT_VALUE);
 
 	return ret;
 }
@@ -2918,8 +2918,7 @@ module_init(igbvf_init_module);
 static void __exit igbvf_exit_module(void)
 {
 	pci_unregister_driver(&igbvf_driver);
-	pm_qos_remove_request(igbvf_driver_pm_qos_req);
-	igbvf_driver_pm_qos_req = NULL;
+	pm_qos_remove_request(&igbvf_driver_pm_qos_req);
 }
 module_exit(igbvf_exit_module);
 
diff --git a/drivers/net/wireless/ipw2x00/ipw2100.c b/drivers/net/wireless/ipw2x00/ipw2100.c
index 0bd4dfa..7f0d98b 100644
--- a/drivers/net/wireless/ipw2x00/ipw2100.c
+++ b/drivers/net/wireless/ipw2x00/ipw2100.c
@@ -174,7 +174,7 @@ that only one external action is invoked at a time.
 #define DRV_DESCRIPTION	"Intel(R) PRO/Wireless 2100 Network Driver"
 #define DRV_COPYRIGHT	"Copyright(c) 2003-2006 Intel Corporation"
 
-struct pm_qos_request_list *ipw2100_pm_qos_req;
+struct pm_qos_request_list ipw2100_pm_qos_req;
 
 /* Debugging stuff */
 #ifdef CONFIG_IPW2100_DEBUG
@@ -1741,7 +1741,7 @@ static int ipw2100_up(struct ipw2100_priv *priv, int deferred)
 	/* the ipw2100 hardware really doesn't want power management delays
 	 * longer than 175usec
 	 */
-	pm_qos_update_request(ipw2100_pm_qos_req, 175);
+	pm_qos_update_request(&ipw2100_pm_qos_req, 175);
 
 	/* If the interrupt is enabled, turn it off... */
 	spin_lock_irqsave(&priv->low_lock, flags);
@@ -1889,7 +1889,7 @@ static void ipw2100_down(struct ipw2100_priv *priv)
 	ipw2100_disable_interrupts(priv);
 	spin_unlock_irqrestore(&priv->low_lock, flags);
 
-	pm_qos_update_request(ipw2100_pm_qos_req, PM_QOS_DEFAULT_VALUE);
+	pm_qos_update_request(&ipw2100_pm_qos_req, PM_QOS_DEFAULT_VALUE);
 
 	/* We have to signal any supplicant if we are disassociating */
 	if (associated)
@@ -6669,8 +6669,8 @@ static int __init ipw2100_init(void)
 	if (ret)
 		goto out;
 
-	ipw2100_pm_qos_req = pm_qos_add_request(PM_QOS_CPU_DMA_LATENCY,
-			PM_QOS_DEFAULT_VALUE);
+	pm_qos_add_request(&ipw2100_pm_qos_req, PM_QOS_CPU_DMA_LATENCY,
+			   PM_QOS_DEFAULT_VALUE);
 #ifdef CONFIG_IPW2100_DEBUG
 	ipw2100_debug_level = debug;
 	ret = driver_create_file(&ipw2100_pci_driver.driver,
@@ -6692,7 +6692,7 @@ static void __exit ipw2100_exit(void)
 			   &driver_attr_debug_level);
 #endif
 	pci_unregister_driver(&ipw2100_pci_driver);
-	pm_qos_remove_request(ipw2100_pm_qos_req);
+	pm_qos_remove_request(&ipw2100_pm_qos_req);
 }
 
 module_init(ipw2100_init);
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index b21e405..2f22119 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -779,7 +779,7 @@ struct net_device {
 	 */
 	char			name[IFNAMSIZ];
 
-	struct pm_qos_request_list *pm_qos_req;
+	struct pm_qos_request_list pm_qos_req;
 
 	/* device name hash chain */
 	struct hlist_node	name_hlist;
diff --git a/include/linux/pm_qos_params.h b/include/linux/pm_qos_params.h
index 8ba440e..77cbddb 100644
--- a/include/linux/pm_qos_params.h
+++ b/include/linux/pm_qos_params.h
@@ -1,8 +1,10 @@
+#ifndef _LINUX_PM_QOS_PARAMS_H
+#define _LINUX_PM_QOS_PARAMS_H
 /* interface for the pm_qos_power infrastructure of the linux kernel.
  *
  * Mark Gross <mgross@linux.intel.com>
  */
-#include <linux/list.h>
+#include <linux/plist.h>
 #include <linux/notifier.h>
 #include <linux/miscdevice.h>
 
@@ -14,9 +16,12 @@
 #define PM_QOS_NUM_CLASSES 4
 #define PM_QOS_DEFAULT_VALUE -1
 
-struct pm_qos_request_list;
+struct pm_qos_request_list {
+	struct plist_node list;
+	int pm_qos_class;
+};
 
-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 *l, int pm_qos_class, s32 value);
 void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req,
 		s32 new_value);
 void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req);
@@ -24,4 +29,6 @@ void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_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_list *req);
 
+#endif
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index dd76cde..6e3a297 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -366,7 +366,7 @@ struct snd_pcm_substream {
 	int number;
 	char name[32];			/* substream name */
 	int stream;			/* stream (direction) */
-	struct pm_qos_request_list *latency_pm_qos_req; /* pm_qos request */
+	struct pm_qos_request_list latency_pm_qos_req; /* pm_qos request */
 	size_t buffer_bytes_max;	/* limit ring buffer size */
 	struct snd_dma_buffer dma_buffer;
 	unsigned int dma_buf_id;
diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index db8e51d..996a4de 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;
 }
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 303ac04..a3b2a64 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -451,13 +451,11 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream,
 	snd_pcm_timer_resolution_change(substream);
 	runtime->status->state = SNDRV_PCM_STATE_SETUP;
 
-	if (substream->latency_pm_qos_req) {
-		pm_qos_remove_request(substream->latency_pm_qos_req);
-		substream->latency_pm_qos_req = NULL;
-	}
+	if (pm_qos_request_active(&substream->latency_pm_qos_req))
+		pm_qos_remove_request(&substream->latency_pm_qos_req);
 	if ((usecs = period_to_usecs(runtime)) >= 0)
-		substream->latency_pm_qos_req = pm_qos_add_request(
-					PM_QOS_CPU_DMA_LATENCY, usecs);
+		pm_qos_add_request(&substream->latency_pm_qos_req,
+				   PM_QOS_CPU_DMA_LATENCY, usecs);
 	return 0;
  _error:
 	/* hardware might be unuseable from this time,
@@ -512,8 +510,7 @@ static int snd_pcm_hw_free(struct snd_pcm_substream *substream)
 	if (substream->ops->hw_free)
 		result = substream->ops->hw_free(substream);
 	runtime->status->state = SNDRV_PCM_STATE_OPEN;
-	pm_qos_remove_request(substream->latency_pm_qos_req);
-	substream->latency_pm_qos_req = NULL;
+	pm_qos_remove_request(&substream->latency_pm_qos_req);
 	return result;
 }