[intel] Bug #13636: Allow recursive buffer mapping in bufmgr_ttm.

2 files changed, 19 insertions, 3 deletions

diff --git a/src/mesa/drivers/dri/common/dri_bufmgr_fake.c b/src/mesa/drivers/dri/common/dri_bufmgr_fake.c
index 7212ee84ab1..8f67798a085 100644
--- a/src/mesa/drivers/dri/common/dri_bufmgr_fake.c
+++ b/src/mesa/drivers/dri/common/dri_bufmgr_fake.c
@@ -712,7 +712,10 @@ dri_fake_bo_map(dri_bo *bo, GLboolean write_enable)
    if (bo_fake->is_static)
       return 0;
 
-   /* Allow recursive mapping, which is used internally in relocation. */
+   /* Allow recursive mapping.  Mesa may recursively map buffers with
+    * nested display loops, and it is used internally in bufmgr_fake
+    * for relocation.
+    */
    if (bo_fake->map_count++ != 0)
       return 0;
 
diff --git a/src/mesa/drivers/dri/intel/intel_bufmgr_ttm.c b/src/mesa/drivers/dri/intel/intel_bufmgr_ttm.c
index e55073b2ef0..fb65e66555a 100644
--- a/src/mesa/drivers/dri/intel/intel_bufmgr_ttm.c
+++ b/src/mesa/drivers/dri/intel/intel_bufmgr_ttm.c
@@ -101,6 +101,7 @@ typedef struct _dri_bo_ttm {
     dri_bo bo;
 
     int refcount;
+    unsigned int map_count;
     drmBO drm_bo;
     const char *name;
 
@@ -338,7 +339,7 @@ dri_ttm_alloc(dri_bufmgr *bufmgr, const char *name,
     uint64_t flags;
     unsigned int hint;
 
-    ttm_buf = malloc(sizeof(*ttm_buf));
+    ttm_buf = calloc(1, sizeof(*ttm_buf));
     if (!ttm_buf)
 	return NULL;
 
@@ -401,7 +402,7 @@ intel_ttm_bo_create_from_handle(dri_bufmgr *bufmgr, const char *name,
     dri_bo_ttm *ttm_buf;
     int ret;
 
-    ttm_buf = malloc(sizeof(*ttm_buf));
+    ttm_buf = calloc(1, sizeof(*ttm_buf));
     if (!ttm_buf)
 	return NULL;
 
@@ -451,6 +452,8 @@ dri_ttm_bo_unreference(dri_bo *buf)
     if (--ttm_buf->refcount == 0) {
 	int ret;
 
+	assert(ttm_buf->map_count == 0);
+
 	if (ttm_buf->reloc_buf_data) {
 	    int i;
 
@@ -499,6 +502,12 @@ dri_ttm_bo_map(dri_bo *buf, GLboolean write_enable)
     if (write_enable)
 	flags |= DRM_BO_FLAG_WRITE;
 
+    /* Allow recursive mapping. Mesa may recursively map buffers with
+     * nested display loops.
+     */
+    if (ttm_buf->map_count++ != 0)
+	return 0;
+
     assert(buf->virtual == NULL);
 
     DBG("bo_map: %p (%s)\n", &ttm_buf->bo, ttm_buf->name);
@@ -528,6 +537,10 @@ dri_ttm_bo_unmap(dri_bo *buf)
     if (buf == NULL)
 	return 0;
 
+    assert(ttm_buf->map_count != 0);
+    if (--ttm_buf->map_count != 0)
+	return 0;
+
     bufmgr_ttm = (dri_bufmgr_ttm *)buf->bufmgr;
 
     assert(buf->virtual != NULL);