i915: Use struct_mutex to protect ring in GEM mode.

In the conversion for GEM, we had stopped using the hardware lock to protect
ring usage, since it was all internal to the DRM now.  However, some paths
weren't converted to using struct_mutex to prevent multiple threads from
concurrently working on the ring, in particular between the vblank swap handler
and ioctls.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 22 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index ea85d71cab04..d71c89f8802e 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -588,9 +588,15 @@ static int i915_quiescent(struct drm_device * dev)
 static int i915_flush_ioctl(struct drm_device *dev, void *data,
                             struct drm_file *file_priv)
 {
-        LOCK_TEST_WITH_RETURN(dev, file_priv);
+        int ret;
+
+        RING_LOCK_TEST_WITH_RETURN(dev, file_priv);
 
-        return i915_quiescent(dev);
+        mutex_lock(&dev->struct_mutex);
+        ret = i915_quiescent(dev);
+        mutex_unlock(&dev->struct_mutex);
+
+        return ret;
 }
 
 static int i915_batchbuffer(struct drm_device *dev, void *data,
@@ -611,14 +617,16 @@ static int i915_batchbuffer(struct drm_device *dev, void *data,
         DRM_DEBUG("i915 batchbuffer, start %x used %d cliprects %d\n",
                   batch->start, batch->used, batch->num_cliprects);
 
-        LOCK_TEST_WITH_RETURN(dev, file_priv);
+        RING_LOCK_TEST_WITH_RETURN(dev, file_priv);
 
         if (batch->num_cliprects && DRM_VERIFYAREA_READ(batch->cliprects,
                                                        batch->num_cliprects *
                                                        sizeof(struct drm_clip_rect)))
                 return -EFAULT;
 
+        mutex_lock(&dev->struct_mutex);
         ret = i915_dispatch_batchbuffer(dev, batch);
+        mutex_unlock(&dev->struct_mutex);
 
         sarea_priv->last_dispatch = (int)hw_status[5];
         return ret;
@@ -637,7 +645,7 @@ static int i915_cmdbuffer(struct drm_device *dev, void *data,
         DRM_DEBUG("i915 cmdbuffer, buf %p sz %d cliprects %d\n",
                   cmdbuf->buf, cmdbuf->sz, cmdbuf->num_cliprects);
 
-        LOCK_TEST_WITH_RETURN(dev, file_priv);
+        RING_LOCK_TEST_WITH_RETURN(dev, file_priv);
 
         if (cmdbuf->num_cliprects &&
             DRM_VERIFYAREA_READ(cmdbuf->cliprects,
@@ -647,7 +655,9 @@ static int i915_cmdbuffer(struct drm_device *dev, void *data,
                 return -EFAULT;
         }
 
+        mutex_lock(&dev->struct_mutex);
         ret = i915_dispatch_cmdbuffer(dev, cmdbuf);
+        mutex_unlock(&dev->struct_mutex);
         if (ret) {
                 DRM_ERROR("i915_dispatch_cmdbuffer failed\n");
                 return ret;
@@ -660,11 +670,17 @@ static int i915_cmdbuffer(struct drm_device *dev, void *data,
 static int i915_flip_bufs(struct drm_device *dev, void *data,
                           struct drm_file *file_priv)
 {
+        int ret;
+
         DRM_DEBUG("%s\n", __func__);
 
-        LOCK_TEST_WITH_RETURN(dev, file_priv);
+        RING_LOCK_TEST_WITH_RETURN(dev, file_priv);
 
-        return i915_dispatch_flip(dev);
+        mutex_lock(&dev->struct_mutex);
+        ret = i915_dispatch_flip(dev);
+        mutex_unlock(&dev->struct_mutex);
+
+        return ret;
 }
 
 static int i915_getparam(struct drm_device *dev, void *data,