drm/etnaviv: submit support for in-fences

Loosely based on commit f0a42bb ("drm/msm: submit support for
in-fences"). Unfortunately, struct drm_etnaviv_gem_submit doesn't have
a flags field yet, so we have to extend the structure and trust that
drm_ioctl will clear the flags for us if an older userspace only submits
part of the struct.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Sumit Semwal <sumit.semwal@linaro.org>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

drivers/gpu/drm/etnaviv/Kconfig

@@ -5,6 +5,7 @@ config DRM_ETNAVIV
 	depends on ARCH_MXC || ARCH_DOVE || (ARM && COMPILE_TEST)
 	depends on MMU
 	select SHMEM
+	select SYNC_FILE
 	select TMPFS
 	select IOMMU_API
 	select IOMMU_SUPPORT

drivers/gpu/drm/etnaviv/etnaviv_gem.h

@@ -107,6 +107,7 @@ struct etnaviv_gem_submit {
 	u32 fence;
 	unsigned int nr_bos;
 	struct etnaviv_gem_submit_bo bos[0];
+	u32 flags;
 };
 
 int etnaviv_gem_wait_bo(struct etnaviv_gpu *gpu, struct drm_gem_object *obj,

drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c

@@ -14,7 +14,9 @@
  * this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/dma-fence-array.h>
 #include <linux/reservation.h>
+#include <linux/sync_file.h>
 #include "etnaviv_cmdbuf.h"
 #include "etnaviv_drv.h"
 #include "etnaviv_gpu.h"
@@ -169,8 +171,10 @@ static int submit_fence_sync(const struct etnaviv_gem_submit *submit)
 	for (i = 0; i < submit->nr_bos; i++) {
 		struct etnaviv_gem_object *etnaviv_obj = submit->bos[i].obj;
 		bool write = submit->bos[i].flags & ETNA_SUBMIT_BO_WRITE;
+		bool explicit = !(submit->flags & ETNA_SUBMIT_NO_IMPLICIT);
 
-		ret = etnaviv_gpu_fence_sync_obj(etnaviv_obj, context, write);
+		ret = etnaviv_gpu_fence_sync_obj(etnaviv_obj, context, write,
+						 explicit);
 		if (ret)
 			break;
 	}
@@ -303,6 +307,7 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 	struct etnaviv_gem_submit *submit;
 	struct etnaviv_cmdbuf *cmdbuf;
 	struct etnaviv_gpu *gpu;
+	struct dma_fence *in_fence = NULL;
 	void *stream;
 	int ret;
 
@@ -326,6 +331,11 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 		return -EINVAL;
 	}
 
+	if (args->flags & ~ETNA_SUBMIT_FLAGS) {
+		DRM_ERROR("invalid flags: 0x%x\n", args->flags);
+		return -EINVAL;
+	}
+
 	/*
 	 * Copy the command submission and bo array to kernel space in
 	 * one go, and do this outside of any locks.
@@ -371,6 +381,8 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 		goto err_submit_cmds;
 	}
 
+	submit->flags = args->flags;
+
 	ret = submit_lookup_objects(submit, file, bos, args->nr_bos);
 	if (ret)
 		goto err_submit_objects;
@@ -385,6 +397,24 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 		goto err_submit_objects;
 	}
 
+	if (args->flags & ETNA_SUBMIT_FENCE_FD_IN) {
+		in_fence = sync_file_get_fence(args->fence_fd);
+		if (!in_fence) {
+			ret = -EINVAL;
+			goto err_submit_objects;
+		}
+
+		/*
+		 * Wait if the fence is from a foreign context, or if the fence
+		 * array contains any fence from a foreign context.
+		 */
+		if (!dma_fence_match_context(in_fence, gpu->fence_context)) {
+			ret = dma_fence_wait(in_fence, true);
+			if (ret)
+				goto err_submit_objects;
+		}
+	}
+
 	ret = submit_fence_sync(submit);
 	if (ret)
 		goto err_submit_objects;
@@ -419,6 +449,8 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void *data,
 		flush_workqueue(priv->wq);
 
 err_submit_objects:
+	if (in_fence)
+		dma_fence_put(in_fence);
 	submit_cleanup(submit);
 
 err_submit_cmds:

drivers/gpu/drm/etnaviv/etnaviv_gpu.c

@@ -1077,7 +1077,7 @@ static struct dma_fence *etnaviv_gpu_fence_alloc(struct etnaviv_gpu *gpu)
 }
 
 int etnaviv_gpu_fence_sync_obj(struct etnaviv_gem_object *etnaviv_obj,
-	unsigned int context, bool exclusive)
+	unsigned int context, bool exclusive, bool explicit)
 {
 	struct reservation_object *robj = etnaviv_obj->resv;
 	struct reservation_object_list *fobj;
@@ -1090,6 +1090,9 @@ int etnaviv_gpu_fence_sync_obj(struct etnaviv_gem_object *etnaviv_obj,
 			return ret;
 	}
 
+	if (explicit)
+		return 0;
+
 	/*
 	 * If we have any shared fences, then the exclusive fence
 	 * should be ignored as it will already have been signalled.

drivers/gpu/drm/etnaviv/etnaviv_gpu.h

@@ -183,7 +183,7 @@ int etnaviv_gpu_debugfs(struct etnaviv_gpu *gpu, struct seq_file *m);
 #endif
 
 int etnaviv_gpu_fence_sync_obj(struct etnaviv_gem_object *etnaviv_obj,
-	unsigned int context, bool exclusive);
+	unsigned int context, bool exclusive, bool implicit);
 
 void etnaviv_gpu_retire(struct etnaviv_gpu *gpu);
 int etnaviv_gpu_wait_fence_interruptible(struct etnaviv_gpu *gpu,

include/uapi/drm/etnaviv_drm.h

@@ -154,6 +154,10 @@ struct drm_etnaviv_gem_submit_bo {
  * one or more cmdstream buffers.  This allows for conditional execution
  * (context-restore), and IB buffers needed for per tile/bin draw cmds.
  */
+#define ETNA_SUBMIT_NO_IMPLICIT         0x0001
+#define ETNA_SUBMIT_FENCE_FD_IN         0x0002
+#define ETNA_SUBMIT_FLAGS		(ETNA_SUBMIT_NO_IMPLICIT | \
+					 ETNA_SUBMIT_FENCE_FD_IN)
 #define ETNA_PIPE_3D      0x00
 #define ETNA_PIPE_2D      0x01
 #define ETNA_PIPE_VG      0x02
@@ -167,6 +171,8 @@ struct drm_etnaviv_gem_submit {
 	__u64 bos;            /* in, ptr to array of submit_bo's */
 	__u64 relocs;         /* in, ptr to array of submit_reloc's */
 	__u64 stream;         /* in, ptr to cmdstream */
+	__u32 flags;          /* in, mask of ETNA_SUBMIT_x */
+	__s32 fence_fd;       /* in, fence fd (see ETNA_SUBMIT_FENCE_FD_IN) */
 };
 
 /* The normal way to synchronize with the GPU is just to CPU_PREP on