gallium: Unify reference counting.

The core reference counting code is centralized in p_refcnt.h.

This has some consequences related to struct pipe_buffer:

* The screen member of struct pipe_buffer must be initialized, or
  pipe_buffer_reference() will crash trying to destroy a buffer with reference
  count 0. u_simple_screen takes care of this, but I may have missed some of
  the drivers not using it.
* Except for rare exceptions deep in winsys code, buffers must always be
  allocated via pipe_buffer_create() or via screen->*buffer_create() rather
  than via winsys->*buffer_create().

3 files changed, 14 insertions, 27 deletions

diff --git a/src/gallium/winsys/drm/intel/gem/intel_be_batchbuffer.c b/src/gallium/winsys/drm/intel/gem/intel_be_batchbuffer.c
index 01374337852..d5e63c3bae5 100644
--- a/src/gallium/winsys/drm/intel/gem/intel_be_batchbuffer.c
+++ b/src/gallium/winsys/drm/intel/gem/intel_be_batchbuffer.c
@@ -114,10 +114,10 @@ intel_be_batchbuffer_flush(struct intel_be_batchbuffer *batch,
 
 	if (fence) {
 		if (*fence)
-			intel_be_fence_unreference(*fence);
+			intel_be_fence_reference(fence, NULL);
 
 		(*fence) = CALLOC_STRUCT(intel_be_fence);
-		(*fence)->refcount = 1;
+		pipe_reference_init(&(*fence)->reference, 1);
 		(*fence)->bo = NULL;
 	}
 }
diff --git a/src/gallium/winsys/drm/intel/gem/intel_be_device.c b/src/gallium/winsys/drm/intel/gem/intel_be_device.c
index 2e191a6d126..de13fb39c7e 100644
--- a/src/gallium/winsys/drm/intel/gem/intel_be_device.c
+++ b/src/gallium/winsys/drm/intel/gem/intel_be_device.c
@@ -51,8 +51,7 @@ intel_be_buffer_unmap(struct pipe_winsys *winsys,
 }
 
 static void
-intel_be_buffer_destroy(struct pipe_winsys *winsys,
-			struct pipe_buffer *buf)
+intel_be_buffer_destroy(struct pipe_buffer *buf)
 {
 	drm_intel_bo_unreference(intel_bo(buf));
 	free(buf);
@@ -72,7 +71,7 @@ intel_be_buffer_create(struct pipe_winsys *winsys,
 	if (!buffer)
 		return NULL;
 
-	buffer->base.refcount = 1;
+	pipe_reference_init(&buffer->base.reference, 1);
 	buffer->base.alignment = alignment;
 	buffer->base.usage = usage;
 	buffer->base.size = size;
@@ -115,7 +114,7 @@ intel_be_user_buffer_create(struct pipe_winsys *winsys, void *ptr, unsigned byte
 	if (!buffer)
 		return NULL;
 
-	buffer->base.refcount = 1;
+	pipe_reference_init(&buffer->base.reference, 1);
 	buffer->base.alignment = 0;
 	buffer->base.usage = 0;
 	buffer->base.size = bytes;
@@ -155,7 +154,7 @@ intel_be_buffer_from_handle(struct pipe_screen *screen,
 	if (!buffer->bo)
 		goto err;
 
-	buffer->base.refcount = 1;
+	pipe_reference_init(&buffer->base.reference, 1);
 	buffer->base.alignment = buffer->bo->align;
 	buffer->base.usage = PIPE_BUFFER_USAGE_GPU_READ |
 	                     PIPE_BUFFER_USAGE_GPU_WRITE |
@@ -215,15 +214,7 @@ intel_be_fence_refunref(struct pipe_winsys *sws,
 	struct intel_be_fence **p = (struct intel_be_fence **)ptr;
 	struct intel_be_fence *f = (struct intel_be_fence *)fence;
 
-	assert(p);
-
-	if (f)
-		intel_be_fence_reference(f);
-
-	if (*p)
-		intel_be_fence_unreference(*p);
-
-	*p = f;
+        intel_be_fence_reference(p, f);
 }
 
 static int
diff --git a/src/gallium/winsys/drm/intel/gem/intel_be_fence.h b/src/gallium/winsys/drm/intel/gem/intel_be_fence.h
index 0fe18f66f83..a8abb01a9ed 100644
--- a/src/gallium/winsys/drm/intel/gem/intel_be_fence.h
+++ b/src/gallium/winsys/drm/intel/gem/intel_be_fence.h
@@ -15,23 +15,19 @@
  */
 struct intel_be_fence
 {
-	uint32_t refcount;
+	struct pipe_reference reference;
 	drm_intel_bo *bo;
 };
 
 static INLINE void
-intel_be_fence_reference(struct intel_be_fence *f)
+intel_be_fence_reference(struct intel_be_fence **ptr, struct intel_be_fence *f)
 {
-	f->refcount++;
-}
+	struct intel_be_fence *old_fence = *ptr;
 
-static INLINE void
-intel_be_fence_unreference(struct intel_be_fence *f)
-{
-	if (!--f->refcount) {
-		if (f->bo)
-			drm_intel_bo_unreference(f->bo);
-		free(f);
+        if (pipe_reference((struct pipe_reference**)ptr, &f->reference)) {
+		if (old_fence->bo)
+			drm_intel_bo_unreference(old_fence->bo);
+		free(old_fence);
 	}
 }