From ea3b40b3035c304dc2121b76fdc6b3c2f9d4c9ba Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 5 Aug 2016 15:40:41 +0100
Subject: [PATCH] drm/amdgpu, drm/radeon, drm/nouveau: Export fences to third
 parties via dma-buf

All three drivers manage their own fence objects on a ttm reservation to
handle internal scheduling. Add that fence to the dma-buf reservation
object as well, so third parties can also schedule using the shared bo
in a completely hackish fashion.
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 11 +++++++++++
 drivers/gpu/drm/drm_gem.c                  | 15 +++++++++++++++
 drivers/gpu/drm/nouveau/nouveau_bo.c       | 10 ++++++++++
 drivers/gpu/drm/radeon/radeon_object.c     | 11 +++++++++++
 include/drm/drm_gem.h                      |  2 ++
 5 files changed, 49 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 6f0873c75a25..a4c711d0851c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -673,4 +673,15 @@ void amdgpu_bo_fence(struct amdgpu_bo *bo, struct fence *fence,
 		reservation_object_add_shared_fence(resv, fence);
 	else
 		reservation_object_add_excl_fence(resv, fence);
+
+	resv = drm_gem_object_get_resv(&bo->gem_base);
+	if (resv) {
+		/* XXX deadlock with caller? */
+		ww_mutex_lock(&resv->lock, NULL);
+		if (shared)
+			reservation_object_add_shared_fence(resv, fence);
+		else
+			reservation_object_add_excl_fence(resv, fence);
+		ww_mutex_unlock(&resv->lock);
+	}
 }
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 9134ae134667..c3f9c3d07d3e 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1004,3 +1004,18 @@ int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 	return ret;
 }
 EXPORT_SYMBOL(drm_gem_mmap);
+
+struct reservation_object *drm_gem_object_get_resv(struct drm_gem_object *obj)
+{
+	struct dma_buf *dma_buf;
+
+	if (obj->dma_buf)
+		dma_buf = obj->dma_buf;
+	else if (obj->import_attach)
+		dma_buf = obj->import_attach->dmabuf;
+	else
+		return NULL;
+
+	return dma_buf->resv;
+}
+EXPORT_SYMBOL(drm_gem_object_get_resv);
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 528bdeffb339..73d586ec08ec 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1551,6 +1551,16 @@ nouveau_bo_fence(struct nouveau_bo *nvbo, struct nouveau_fence *fence, bool excl
 		reservation_object_add_excl_fence(resv, &fence->base);
 	else if (fence)
 		reservation_object_add_shared_fence(resv, &fence->base);
+
+	resv = drm_gem_object_get_resv(&nvbo->gem);
+	if (resv) {
+		ww_mutex_lock(&resv->lock, NULL);
+		if (exclusive)
+			reservation_object_add_excl_fence(resv, &fence->base);
+		else if (fence)
+			reservation_object_add_shared_fence(resv, &fence->base);
+		ww_mutex_unlock(&resv->lock);
+	}
 }
 
 struct ttm_bo_driver nouveau_bo_driver = {
diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
index be30861afae9..294c10988c15 100644
--- a/drivers/gpu/drm/radeon/radeon_object.c
+++ b/drivers/gpu/drm/radeon/radeon_object.c
@@ -860,4 +860,15 @@ void radeon_bo_fence(struct radeon_bo *bo, struct radeon_fence *fence,
 		reservation_object_add_shared_fence(resv, &fence->base);
 	else
 		reservation_object_add_excl_fence(resv, &fence->base);
+
+	resv = drm_gem_object_get_resv(&bo->gem_base);
+	if (resv) {
+		/* XXX deadlock with caller? */
+		ww_mutex_lock(&resv->lock, NULL);
+		if (shared)
+			reservation_object_add_shared_fence(resv, &fence->base);
+		else
+			reservation_object_add_excl_fence(resv, &fence->base);
+		ww_mutex_unlock(&resv->lock);
+	}
 }
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index f06f6c53f476..a5055b667eca 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -228,4 +228,6 @@ int drm_gem_dumb_destroy(struct drm_file *file,
 			 struct drm_device *dev,
 			 uint32_t handle);
 
+struct reservation_object *drm_gem_object_get_resv(struct drm_gem_object *obj);
+
 #endif /* __DRM_GEM_H__ */
-- 
2.8.1