drm/msm: submit support for in-fences

Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/Kconfig

@@ -11,6 +11,7 @@ config DRM_MSM
 	select TMPFS
 	select QCOM_SCM
 	select SND_SOC_HDMI_CODEC if SND_SOC
+	select SYNC_FILE
 	default y
 	help
 	  DRM/KMS driver for MSM/snapdragon.

drivers/gpu/drm/msm/msm_gem_submit.c

@@ -15,6 +15,8 @@
  * this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/sync_file.h>
+
 #include "msm_drv.h"
 #include "msm_gpu.h"
 #include "msm_gem.h"
@@ -361,6 +363,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	struct msm_file_private *ctx = file->driver_priv;
 	struct msm_gem_submit *submit;
 	struct msm_gpu *gpu = priv->gpu;
+	struct fence *in_fence = NULL;
 	unsigned i;
 	int ret;
 
@@ -394,9 +397,32 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	if (ret)
 		goto out;
 
-	ret = submit_fence_sync(submit);
-	if (ret)
-		goto out;
+	if (args->flags & MSM_SUBMIT_FENCE_FD_IN) {
+		in_fence = sync_file_get_fence(args->fence_fd);
+
+		if (!in_fence) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		/* TODO if we get an array-fence due to userspace merging multiple
+		 * fences, we need a way to determine if all the backing fences
+		 * are from our own context..
+		 */
+
+		if (in_fence->context != gpu->fctx->context) {
+			ret = fence_wait(in_fence, true);
+			if (ret)
+				goto out;
+		}
+
+	}
+
+	if (!(args->fence & MSM_SUBMIT_NO_IMPLICIT)) {
+		ret = submit_fence_sync(submit);
+		if (ret)
+			goto out;
+	}
 
 	ret = submit_pin_objects(submit);
 	if (ret)
@@ -467,6 +493,8 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
 	args->fence = submit->fence->seqno;
 
 out:
+	if (in_fence)
+		fence_put(in_fence);
 	submit_cleanup(submit);
 	if (ret)
 		msm_gem_submit_free(submit);

include/uapi/drm/msm_drm.h

@@ -185,8 +185,12 @@ struct drm_msm_gem_submit_bo {
 };
 
 /* Valid submit ioctl flags: */
-/* to start, nothing.. */
-#define MSM_SUBMIT_FLAGS 0
+#define MSM_SUBMIT_NO_IMPLICIT   0x80000000 /* disable implicit sync */
+#define MSM_SUBMIT_FENCE_FD_IN   0x40000000 /* enable input fence_fd */
+#define MSM_SUBMIT_FLAGS                ( \
+		MSM_SUBMIT_NO_IMPLICIT   | \
+		MSM_SUBMIT_FENCE_FD_IN   | \
+		0)
 
 /* Each cmdstream submit consists of a table of buffers involved, and
  * one or more cmdstream buffers.  This allows for conditional execution
@@ -199,6 +203,7 @@ struct drm_msm_gem_submit {
 	__u32 nr_cmds;        /* in, number of submit_cmd's */
 	__u64 __user bos;     /* in, ptr to array of submit_bo's */
 	__u64 __user cmds;    /* in, ptr to array of submit_cmd's */
+	__s32 fence_fd;       /* in/out fence fd (see MSM_SUBMIT_FENCE_FD_IN) */
 };
 
 /* The normal way to synchronize with the GPU is just to CPU_PREP on