[Intel-gfx] [PATCH] intel: Adding locks for drm objects synchronization.

[Rafal Sapala]

The changes make sure that members of the bufmgr_gem and bo_gem
name lists are sychronized between threads
when using the create from prime and create from name methods.

Signed-off-by: Rafal Sapala <rafal.a.sapala at intel.com>
---
 intel/intel_bufmgr_gem.c |   28 ++++++++++++++++++++++++----
 1 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
index 007a6d8..243f563 100644
--- a/intel/intel_bufmgr_gem.c
+++ b/intel/intel_bufmgr_gem.c
@@ -871,12 +871,14 @@ drm_intel_bo_gem_create_from_name(drm_intel_bufmgr *bufmgr,
 	 * alternating names for the front/back buffer a linear search
 	 * provides a sufficiently fast match.
 	 */
+	pthread_mutex_lock(&bufmgr_gem->lock);
 	for (list = bufmgr_gem->named.next;
 	     list != &bufmgr_gem->named;
 	     list = list->next) {
 		bo_gem = DRMLISTENTRY(drm_intel_bo_gem, list, name_list);
 		if (bo_gem->global_name == handle) {
 			drm_intel_gem_bo_reference(&bo_gem->bo);
+			pthread_mutex_unlock(&bufmgr_gem->lock);
 			return &bo_gem->bo;
 		}
 	}
@@ -889,6 +891,7 @@ drm_intel_bo_gem_create_from_name(drm_intel_bufmgr *bufmgr,
 	if (ret != 0) {
 		DBG("Couldn't reference %s handle 0x%08x: %s\n",
 		    name, handle, strerror(errno));
+		pthread_mutex_unlock(&bufmgr_gem->lock);
 		return NULL;
 	}
         /* Now see if someone has used a prime handle to get this
@@ -901,13 +904,16 @@ drm_intel_bo_gem_create_from_name(drm_intel_bufmgr *bufmgr,
 		bo_gem = DRMLISTENTRY(drm_intel_bo_gem, list, name_list);
 		if (bo_gem->gem_handle == open_arg.handle) {
 			drm_intel_gem_bo_reference(&bo_gem->bo);
+			pthread_mutex_unlock(&bufmgr_gem->lock);
 			return &bo_gem->bo;
 		}
 	}
 
 	bo_gem = calloc(1, sizeof(*bo_gem));
-	if (!bo_gem)
+	if (!bo_gem) {
+		pthread_mutex_unlock(&bufmgr_gem->lock);
 		return NULL;
+	}
 
 	bo_gem->bo.size = open_arg.size;
 	bo_gem->bo.offset = 0;
@@ -929,6 +935,7 @@ drm_intel_bo_gem_create_from_name(drm_intel_bufmgr *bufmgr,
 		       &get_tiling);
 	if (ret != 0) {
 		drm_intel_gem_bo_unreference(&bo_gem->bo);
+		pthread_mutex_unlock(&bufmgr_gem->lock);
 		return NULL;
 	}
 	bo_gem->tiling_mode = get_tiling.tiling_mode;
@@ -938,6 +945,7 @@ drm_intel_bo_gem_create_from_name(drm_intel_bufmgr *bufmgr,
 
 	DRMINITLISTHEAD(&bo_gem->vma_list);
 	DRMLISTADDTAIL(&bo_gem->name_list, &bufmgr_gem->named);
+	pthread_mutex_unlock(&bufmgr_gem->lock);
 	DBG("bo_create_from_handle: %d (%s)\n", handle, bo_gem->name);
 
 	return &bo_gem->bo;
@@ -2502,25 +2510,29 @@ drm_intel_bo_gem_create_from_prime(drm_intel_bufmgr *bufmgr, int prime_fd, int s
 	 * for named buffers, we must not create two bo's pointing at the same
 	 * kernel object
 	 */
+	pthread_mutex_lock(&bufmgr_gem->lock);
 	for (list = bufmgr_gem->named.next;
 	     list != &bufmgr_gem->named;
 	     list = list->next) {
 		bo_gem = DRMLISTENTRY(drm_intel_bo_gem, list, name_list);
 		if (bo_gem->gem_handle == handle) {
 			drm_intel_gem_bo_reference(&bo_gem->bo);
+			pthread_mutex_unlock(&bufmgr_gem->lock);
 			return &bo_gem->bo;
 		}
 	}
 
 	if (ret) {
 	  fprintf(stderr,"ret is %d %d\n", ret, errno);
+	  pthread_mutex_unlock(&bufmgr_gem->lock);
 		return NULL;
 	}
 
 	bo_gem = calloc(1, sizeof(*bo_gem));
-	if (!bo_gem)
+	if (!bo_gem) {
+		pthread_mutex_unlock(&bufmgr_gem->lock);
 		return NULL;
-
+	}
 	/* Determine size of bo.  The fd-to-handle ioctl really should
 	 * return the size, but it doesn't.  If we have kernel 3.12 or
 	 * later, we can lseek on the prime fd to get the size.  Older
@@ -2548,6 +2560,7 @@ drm_intel_bo_gem_create_from_prime(drm_intel_bufmgr *bufmgr, int prime_fd, int s
 
 	DRMINITLISTHEAD(&bo_gem->vma_list);
 	DRMLISTADDTAIL(&bo_gem->name_list, &bufmgr_gem->named);
+	pthread_mutex_unlock(&bufmgr_gem->lock);
 
 	VG_CLEAR(get_tiling);
 	get_tiling.handle = bo_gem->gem_handle;
@@ -2572,8 +2585,10 @@ drm_intel_bo_gem_export_to_prime(drm_intel_bo *bo, int *prime_fd)
 	drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
 	drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
 
+	pthread_mutex_lock(&bufmgr_gem->lock);
         if (DRMLISTEMPTY(&bo_gem->name_list))
                 DRMLISTADDTAIL(&bo_gem->name_list, &bufmgr_gem->named);
+	pthread_mutex_unlock(&bufmgr_gem->lock);
 
 	if (drmPrimeHandleToFD(bufmgr_gem->fd, bo_gem->gem_handle,
 			       DRM_CLOEXEC, prime_fd) != 0)
@@ -2597,15 +2612,20 @@ drm_intel_gem_bo_flink(drm_intel_bo *bo, uint32_t * name)
 		VG_CLEAR(flink);
 		flink.handle = bo_gem->gem_handle;
 
+		pthread_mutex_lock(&bufmgr_gem->lock);
+
 		ret = drmIoctl(bufmgr_gem->fd, DRM_IOCTL_GEM_FLINK, &flink);
-		if (ret != 0)
+		if (ret != 0) {
+			pthread_mutex_unlock(&bufmgr_gem->lock);
 			return -errno;
+		}
 
 		bo_gem->global_name = flink.name;
 		bo_gem->reusable = false;
 
                 if (DRMLISTEMPTY(&bo_gem->name_list))
                         DRMLISTADDTAIL(&bo_gem->name_list, &bufmgr_gem->named);
+		pthread_mutex_unlock(&bufmgr_gem->lock);
 	}
 
 	*name = bo_gem->global_name;
-- 
1.7.1

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