[PATCH 3/4] drm/radeon: add DONT_SYNC flag to CS relocs

[Christian König]

From: Christian König <christian.koenig at amd.com>

This allows userspace to explicitly don't sync submission to
different rings as long as all uses stay in the same client.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/radeon/radeon.h     |  3 +++
 drivers/gpu/drm/radeon/radeon_cs.c  | 23 ++++++++++++++++++++++-
 drivers/gpu/drm/radeon/radeon_gem.c |  1 +
 drivers/gpu/drm/radeon/radeon_ttm.c |  3 +++
 include/uapi/drm/radeon_drm.h       |  2 ++
 5 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index c0f7773..740a0b2 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -478,6 +478,8 @@ struct radeon_bo {
 	u32				tiling_flags;
 	u32				pitch;
 	int				surface_reg;
+	struct drm_file			*last_user;
+	struct radeon_fence		*last_sync;
 	struct radeon_fence		*written;
 	/* list of all virtual address to which this bo
 	 * is associated to
@@ -1018,6 +1020,7 @@ struct radeon_cs_reloc {
 	unsigned			allowed_domains;
 	uint32_t			tiling_flags;
 	uint32_t			handle;
+	uint32_t			flags;
 	bool				written;
 };
 
diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index 3aa7e48..11e4789 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -166,6 +166,7 @@ static int radeon_cs_parser_relocs(struct radeon_cs_parser *p)
 
 		p->relocs[i].tv.bo = &p->relocs[i].robj->tbo;
 		p->relocs[i].handle = r->handle;
+		p->relocs[i].flags = r->flags;
 		p->relocs[i].written = !!r->write_domain;
 
 		radeon_cs_buckets_add(&buckets, &p->relocs[i].tv.head,
@@ -236,6 +237,14 @@ static void radeon_cs_sync_rings(struct radeon_cs_parser *p)
 		if (!bo)
 			continue;
 
+		/* always sync to the last operation
+		   the clients doesn't know about */
+		radeon_semaphore_sync_to(p->ib.presync, bo->last_sync);
+
+		if (bo->last_user == p->filp &&
+		    reloc->flags & RADEON_RELOC_DONT_SYNC)
+			continue;
+
 		fence = bo->tbo.sync_obj;
 
 		if (bo->written && radeon_fence_signaled(bo->written))
@@ -421,7 +430,19 @@ static void radeon_cs_parser_fini(struct radeon_cs_parser *parser, int error, bo
 			struct radeon_cs_reloc *reloc = &parser->relocs[i];
 			struct radeon_bo *bo = reloc->robj;
 
-			if (!bo || !reloc->written)
+			if (!bo)
+				continue;
+
+			/* if the client changes remember that and always serialize
+			   all operations from different clients */
+			if (bo->last_user != parser->filp && bo->tbo.sync_obj) {
+				struct radeon_fence *fence = bo->tbo.sync_obj;
+				radeon_fence_unref(&bo->last_sync);
+				bo->last_sync = radeon_fence_ref(fence);
+			}
+			bo->last_user = parser->filp;
+
+			if (!reloc->written)
 				continue;
 
 			radeon_fence_unref(&bo->written);
diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
index bfd7e1b..c73dbc1 100644
--- a/drivers/gpu/drm/radeon/radeon_gem.c
+++ b/drivers/gpu/drm/radeon/radeon_gem.c
@@ -259,6 +259,7 @@ int radeon_gem_create_ioctl(struct drm_device *dev, void *data,
 		r = radeon_gem_handle_lockup(rdev, r);
 		return r;
 	}
+	gem_to_radeon_bo(gobj)->last_user = filp;
 	r = drm_gem_handle_create(filp, gobj, &handle);
 	/* drop reference from allocate - handle holds it now */
 	drm_gem_object_unreference_unlocked(gobj);
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index 76be612..a4f964f 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -273,6 +273,9 @@ static int radeon_move_blit(struct ttm_buffer_object *bo,
 			&fence);
 
 	if (!r) {
+		rbo->last_user = NULL;
+		radeon_fence_unref(&rbo->last_sync);
+		rbo->last_sync = radeon_fence_ref(fence);
 		radeon_fence_unref(&rbo->written);
 		rbo->written = radeon_fence_ref(fence);
 	}
diff --git a/include/uapi/drm/radeon_drm.h b/include/uapi/drm/radeon_drm.h
index 509b2d7..5bd3f68 100644
--- a/include/uapi/drm/radeon_drm.h
+++ b/include/uapi/drm/radeon_drm.h
@@ -944,6 +944,8 @@ struct drm_radeon_cs_chunk {
 };
 
 /* drm_radeon_cs_reloc.flags */
+#define RADEON_RELOC_PRIO_MASK		(0xf << 0)
+#define RADEON_RELOC_DONT_SYNC		(1 << 4)
 
 struct drm_radeon_cs_reloc {
 	uint32_t		handle;
-- 
1.9.1