[PATCH 12/15] drm: add user fence support to drm_gem_plane_helper_prepare_fb

[Christian König]

Just handle them the same way as fences with the DMA_RESV_USAGE_WRITE
flag when the DRIVER_USER_FENCE flag is set.

Signed-off-by: Christian König <christian.koe...@amd.com>
---
 drivers/gpu/drm/drm_gem_atomic_helper.c | 68 ++++++++++++++++---------
 1 file changed, 45 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_atomic_helper.c 
b/drivers/gpu/drm/drm_gem_atomic_helper.c
index a5026f617739..75d04333ff2e 100644
--- a/drivers/gpu/drm/drm_gem_atomic_helper.c
+++ b/drivers/gpu/drm/drm_gem_atomic_helper.c
@@ -5,6 +5,7 @@
 
 #include <drm/drm_atomic_state_helper.h>
 #include <drm/drm_atomic_uapi.h>
+#include <drm/drm_drv.h>
 #include <drm/drm_gem.h>
 #include <drm/drm_gem_atomic_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
@@ -121,6 +122,40 @@
  * Plane Helpers
  */
 
+static int chain_fb_fences(struct drm_framebuffer *fb,
+                          enum dma_resv_usage usage,
+                          struct dma_fence **fence)
+{
+       size_t i;
+       int ret;
+
+       for (i = 0; i < fb->format->num_planes; ++i) {
+               struct drm_gem_object *obj = drm_gem_fb_get_obj(fb, i);
+               struct dma_fence *new;
+
+               if (WARN_ON_ONCE(!obj))
+                       continue;
+
+               ret = dma_resv_get_singleton(obj->resv, usage, &new);
+               if (ret)
+                       return ret;
+
+               if (new && *fence) {
+                       struct dma_fence_chain *chain = dma_fence_chain_alloc();
+
+                       if (!chain)
+                               return -ENOMEM;
+
+                       dma_fence_chain_init(chain, *fence, new, 1);
+                       *fence = &chain->base;
+
+               } else if (new) {
+                       *fence = new;
+               }
+       }
+       return 0;
+}
+
 /**
  * drm_gem_plane_helper_prepare_fb() - Prepare a GEM backed framebuffer
  * @plane: Plane
@@ -143,8 +178,6 @@ int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane,
                                    struct drm_plane_state *state)
 {
        struct dma_fence *fence = dma_fence_get(state->fence);
-       enum dma_resv_usage usage;
-       size_t i;
        int ret;
 
        if (!state->fb)
@@ -163,32 +196,21 @@ int drm_gem_plane_helper_prepare_fb(struct drm_plane 
*plane,
         * obeys both implicit and explicit fences for plane updates, then it
         * will break all the benefits of explicit fencing.
         */
-       usage = fence ? DMA_RESV_USAGE_KERNEL : DMA_RESV_USAGE_WRITE;
-
-       for (i = 0; i < state->fb->format->num_planes; ++i) {
-               struct drm_gem_object *obj = drm_gem_fb_get_obj(state->fb, i);
-               struct dma_fence *new;
-
-               if (WARN_ON_ONCE(!obj))
-                       continue;
-
-               ret = dma_resv_get_singleton(obj->resv, usage, &new);
+       if (fence) {
+               ret = chain_fb_fences(state->fb, DMA_RESV_USAGE_KERNEL, &fence);
                if (ret)
                        goto error;
 
-               if (new && fence) {
-                       struct dma_fence_chain *chain = dma_fence_chain_alloc();
+       } else {
+               ret = chain_fb_fences(state->fb, DMA_RESV_USAGE_WRITE, &fence);
+               if (ret)
+                       goto error;
 
-                       if (!chain) {
-                               ret = -ENOMEM;
+               if (drm_core_check_feature(plane->dev, DRIVER_USER_FENCE)) {
+                       ret = chain_fb_fences(state->fb, DMA_RESV_USAGE_USER,
+                                             &fence);
+                       if (ret)
                                goto error;
-                       }
-
-                       dma_fence_chain_init(chain, fence, new, 1);
-                       fence = &chain->base;
-
-               } else if (new) {
-                       fence = new;
                }
        }
 
-- 
2.25.1