drm/msm: Add MSM_SUBMIT_BO_NO_IMPLICIT

In cases where implicit sync is used, it is still useful (for things
like sub-allocation, etc) to allow userspace to opt-out of implicit
sync on per-BO basis.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/514216/
Link: https://lore.kernel.org/r/20221206192123.661448-1-robdclark@gmail.com

drivers/gpu/drm/msm/msm_drv.c

@@ -45,9 +45,10 @@
  * - 1.7.0 - Add MSM_PARAM_SUSPENDS to access suspend count
  * - 1.8.0 - Add MSM_BO_CACHED_COHERENT for supported GPUs (a6xx)
  * - 1.9.0 - Add MSM_SUBMIT_FENCE_SN_IN
+ * - 1.10.0 - Add MSM_SUBMIT_BO_NO_IMPLICIT
  */
 #define MSM_VERSION_MAJOR	1
-#define MSM_VERSION_MINOR	9
+#define MSM_VERSION_MINOR	10
 #define MSM_VERSION_PATCHLEVEL	0
 
 static const struct drm_mode_config_funcs mode_config_funcs = {

drivers/gpu/drm/msm/msm_gem_submit.c

@@ -334,9 +334,20 @@ static int submit_fence_sync(struct msm_gem_submit *submit, bool no_implicit)
 		if (ret)
 			return ret;
 
+		/* If userspace has determined that explicit fencing is
+		 * used, it can disable implicit sync on the entire
+		 * submit:
+		 */
 		if (no_implicit)
 			continue;
 
+		/* Otherwise userspace can ask for implicit sync to be
+		 * disabled on specific buffers.  This is useful for internal
+		 * usermode driver managed buffers, suballocation, etc.
+		 */
+		if (submit->bos[i].flags & MSM_SUBMIT_BO_NO_IMPLICIT)
+			continue;
+
 		ret = drm_sched_job_add_implicit_dependencies(&submit->base,
 							      obj,
 							      write);

include/uapi/drm/msm_drm.h

@@ -222,10 +222,12 @@ struct drm_msm_gem_submit_cmd {
 #define MSM_SUBMIT_BO_READ             0x0001
 #define MSM_SUBMIT_BO_WRITE            0x0002
 #define MSM_SUBMIT_BO_DUMP             0x0004
+#define MSM_SUBMIT_BO_NO_IMPLICIT      0x0008
 
 #define MSM_SUBMIT_BO_FLAGS            (MSM_SUBMIT_BO_READ | \
 					MSM_SUBMIT_BO_WRITE | \
-					MSM_SUBMIT_BO_DUMP)
+					MSM_SUBMIT_BO_DUMP | \
+					MSM_SUBMIT_BO_NO_IMPLICIT)
 
 struct drm_msm_gem_submit_bo {
 	__u32 flags;          /* in, mask of MSM_SUBMIT_BO_x */