drm/nouveau: Add unlocked variants of nouveau_channel_get/put.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

2 files changed, 26 insertions, 13 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_channel.c b/drivers/gpu/drm/nouveau/nouveau_channel.c
index c46a6f641964..38929fd3f4e3 100644
--- a/drivers/gpu/drm/nouveau/nouveau_channel.c
+++ b/drivers/gpu/drm/nouveau/nouveau_channel.c
@@ -238,33 +238,39 @@ nouveau_channel_alloc(struct drm_device *dev, struct nouveau_channel **chan_ret,
 }
 
 struct nouveau_channel *
+nouveau_channel_get_unlocked(struct nouveau_channel *ref)
+{
+        if (likely(ref && atomic_inc_not_zero(&ref->refcount)))
+                return ref;
+
+        return NULL;
+}
+
+struct nouveau_channel *
 nouveau_channel_get(struct drm_device *dev, struct drm_file *file_priv, int id)
 {
         struct drm_nouveau_private *dev_priv = dev->dev_private;
-        struct nouveau_channel *chan = ERR_PTR(-ENODEV);
+        struct nouveau_channel *chan;
         unsigned long flags;
 
         spin_lock_irqsave(&dev_priv->channels.lock, flags);
-        chan = dev_priv->channels.ptr[id];
+        chan = nouveau_channel_get_unlocked(dev_priv->channels.ptr[id]);
+        spin_unlock_irqrestore(&dev_priv->channels.lock, flags);
 
-        if (unlikely(!chan || (file_priv && chan->file_priv != file_priv))) {
-                spin_unlock_irqrestore(&dev_priv->channels.lock, flags);
+        if (unlikely(!chan))
                 return ERR_PTR(-EINVAL);
-        }
 
-        if (unlikely(!atomic_inc_not_zero(&chan->refcount))) {
-                spin_unlock_irqrestore(&dev_priv->channels.lock, flags);
+        if (unlikely(file_priv && chan->file_priv != file_priv)) {
+                nouveau_channel_put_unlocked(&chan);
                 return ERR_PTR(-EINVAL);
         }
 
-        spin_unlock_irqrestore(&dev_priv->channels.lock, flags);
-
         mutex_lock(&chan->mutex);
         return chan;
 }
 
 void
-nouveau_channel_put(struct nouveau_channel **pchan)
+nouveau_channel_put_unlocked(struct nouveau_channel **pchan)
 {
         struct nouveau_channel *chan = *pchan;
         struct drm_device *dev = chan->dev;
@@ -274,9 +280,6 @@ nouveau_channel_put(struct nouveau_channel **pchan)
         unsigned long flags;
         int ret;
 
-        /* unlock the channel */
-        mutex_unlock(&chan->mutex);
-
         /* decrement the refcount, and we're done if there's still refs */
         if (likely(!atomic_dec_and_test(&chan->refcount))) {
                 *pchan = NULL;
@@ -348,6 +351,13 @@ nouveau_channel_put(struct nouveau_channel **pchan)
         kfree(chan);
 }
 
+void
+nouveau_channel_put(struct nouveau_channel **pchan)
+{
+        mutex_unlock(&(*pchan)->mutex);
+        nouveau_channel_put_unlocked(pchan);
+}
+
 /* cleans up all the fifos from file_priv */
 void
 nouveau_channel_cleanup(struct drm_device *dev, struct drm_file *file_priv)
diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index 198dabebafb2..e6708be58bcf 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -803,7 +803,10 @@ extern int  nouveau_channel_alloc(struct drm_device *dev,
                                   struct drm_file *file_priv,
                                   uint32_t fb_ctxdma, uint32_t tt_ctxdma);
 extern struct nouveau_channel *
+nouveau_channel_get_unlocked(struct nouveau_channel *);
+extern struct nouveau_channel *
 nouveau_channel_get(struct drm_device *, struct drm_file *, int id);
+extern void nouveau_channel_put_unlocked(struct nouveau_channel **);
 extern void nouveau_channel_put(struct nouveau_channel **);
 
 /* nouveau_object.c */