[PATCH 19/23] dma-buf: add DMA_RESV_USAGE_KERNEL

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

Add an usage for kernel submissions. Waiting for those
are mandatory for dynamic DMA-bufs.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/dma-buf/st-dma-resv.c                |  2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c   |  2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c      |  2 +-
 drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c |  6 ++++--
 drivers/gpu/drm/i915/gem/i915_gem_clflush.c  |  2 +-
 drivers/gpu/drm/nouveau/nouveau_bo.c         |  4 ++--
 drivers/gpu/drm/radeon/radeon_uvd.c          |  2 +-
 drivers/gpu/drm/ttm/ttm_bo.c                 |  2 +-
 drivers/gpu/drm/ttm/ttm_bo_util.c            |  4 ++--
 drivers/gpu/drm/vmwgfx/vmwgfx_bo.c           |  2 +-
 drivers/gpu/drm/vmwgfx/vmwgfx_resource.c     |  2 +-
 drivers/infiniband/core/umem_dmabuf.c        |  2 +-
 include/linux/dma-resv.h                     | 22 ++++++++++++++++++++
 13 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/drivers/dma-buf/st-dma-resv.c b/drivers/dma-buf/st-dma-resv.c
index d0f7c2bfd4f0..062b57d63fa6 100644
--- a/drivers/dma-buf/st-dma-resv.c
+++ b/drivers/dma-buf/st-dma-resv.c
@@ -296,7 +296,7 @@ int dma_resv(void)
 	int r;
 
 	spin_lock_init(&fence_lock);
-	for (usage = DMA_RESV_USAGE_WRITE; usage <= DMA_RESV_USAGE_READ;
+	for (usage = DMA_RESV_USAGE_KERNEL; usage <= DMA_RESV_USAGE_READ;
 	     ++usage) {
 		r = subtests(tests, (void *)(unsigned long)usage);
 		if (r)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 7b506eb96a65..f3e6ef53c08e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -765,7 +765,7 @@ int amdgpu_bo_kmap(struct amdgpu_bo *bo, void **ptr)
 		return 0;
 	}
 
-	r = dma_resv_wait_timeout(bo->tbo.base.resv, DMA_RESV_USAGE_WRITE,
+	r = dma_resv_wait_timeout(bo->tbo.base.resv, DMA_RESV_USAGE_KERNEL,
 				  false, MAX_SCHEDULE_TIMEOUT);
 	if (r < 0)
 		return r;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c
index 33deb0df62fd..9e102080dad9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c
@@ -1163,7 +1163,7 @@ static int amdgpu_uvd_send_msg(struct amdgpu_ring *ring, struct amdgpu_bo *bo,
 
 	if (direct) {
 		r = dma_resv_wait_timeout(bo->tbo.base.resv,
-					  DMA_RESV_USAGE_WRITE, false,
+					  DMA_RESV_USAGE_KERNEL, false,
 					  msecs_to_jiffies(10));
 		if (r == 0)
 			r = -ETIMEDOUT;
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
index 0cc036d93afc..ab5249d55b32 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
@@ -185,9 +185,11 @@ static int submit_fence_sync(struct etnaviv_gem_submit *submit)
 			return ret;
 
 		if (submit->flags & ETNA_SUBMIT_NO_IMPLICIT)
-			continue;
+			usage = DMA_RESV_USAGE_KERNEL;
+		else
+			usage = dma_resv_usage_rw(bo->flags &
+						  ETNA_SUBMIT_BO_WRITE);
 
-		usage = dma_resv_usage_rw(bo->flags & ETNA_SUBMIT_BO_WRITE);
 		ret = dma_resv_get_fences(robj, usage, &bo->nr_shared,
 					  &bo->shared);
 		if (ret)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
index 887cb6b71ae4..9a7104251cb3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_clflush.c
@@ -115,7 +115,7 @@ bool i915_gem_clflush_object(struct drm_i915_gem_object *obj,
 						i915_fence_timeout(i915),
 						I915_FENCE_GFP);
 		dma_resv_add_fence(obj->base.resv, &clflush->base.dma,
-				   DMA_RESV_USAGE_WRITE);
+				   DMA_RESV_USAGE_KERNEL);
 		dma_fence_work_commit(&clflush->base);
 		/*
 		 * We must have successfully populated the pages(since we are
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 05076e530e7d..13deb6c70ba6 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -962,10 +962,10 @@ nouveau_bo_vm_cleanup(struct ttm_buffer_object *bo,
 	struct dma_fence *fence;
 	int ret;
 
-	ret = dma_resv_get_singleton(bo->base.resv, DMA_RESV_USAGE_WRITE,
+	ret = dma_resv_get_singleton(bo->base.resv, DMA_RESV_USAGE_KERNEL,
 				     &fence);
 	if (ret)
-		dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_WRITE,
+		dma_resv_wait_timeout(bo->base.resv, DMA_RESV_USAGE_KERNEL,
 				      false, MAX_SCHEDULE_TIMEOUT);
 
 	nv10_bo_put_tile_region(dev, *old_tile, fence);
diff --git a/drivers/gpu/drm/radeon/radeon_uvd.c b/drivers/gpu/drm/radeon/radeon_uvd.c
index 4000ad2f39ba..488e78889dd6 100644
--- a/drivers/gpu/drm/radeon/radeon_uvd.c
+++ b/drivers/gpu/drm/radeon/radeon_uvd.c
@@ -478,7 +478,7 @@ static int radeon_uvd_cs_msg(struct radeon_cs_parser *p, struct radeon_bo *bo,
 		return -EINVAL;
 	}
 
-	r = dma_resv_wait_timeout(bo->tbo.base.resv, DMA_RESV_USAGE_WRITE,
+	r = dma_resv_wait_timeout(bo->tbo.base.resv, DMA_RESV_USAGE_KERNEL,
 				  false, MAX_SCHEDULE_TIMEOUT);
 	if (r <= 0) {
 		DRM_ERROR("Failed waiting for UVD message (%d)!\n", r);
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 6014c363d6e6..0f0aa96fb051 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -762,7 +762,7 @@ static int ttm_bo_add_move_fence(struct ttm_buffer_object *bo,
 		return ret;
 	}
 
-	dma_resv_add_fence(bo->base.resv, fence, DMA_RESV_USAGE_WRITE);
+	dma_resv_add_fence(bo->base.resv, fence, DMA_RESV_USAGE_KERNEL);
 
 	ret = dma_resv_reserve_fences(bo->base.resv, 1);
 	if (unlikely(ret)) {
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 49689c7c8078..98e1c804519e 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -509,7 +509,7 @@ static int ttm_bo_move_to_ghost(struct ttm_buffer_object *bo,
 		return ret;
 
 	dma_resv_add_fence(&ghost_obj->base._resv, fence,
-			   DMA_RESV_USAGE_WRITE);
+			   DMA_RESV_USAGE_KERNEL);
 
 	/**
 	 * If we're not moving to fixed memory, the TTM object
@@ -563,7 +563,7 @@ int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
 	struct ttm_resource_manager *man = ttm_manager_type(bdev, new_mem->mem_type);
 	int ret = 0;
 
-	dma_resv_add_fence(bo->base.resv, fence, DMA_RESV_USAGE_WRITE);
+	dma_resv_add_fence(bo->base.resv, fence, DMA_RESV_USAGE_KERNEL);
 	if (!evict)
 		ret = ttm_bo_move_to_ghost(bo, fence, man->use_tt);
 	else if (!from->use_tt && pipeline)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
index bec50223efe5..408ede1f967f 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
@@ -759,7 +759,7 @@ void vmw_bo_fence_single(struct ttm_buffer_object *bo,
 	ret = dma_resv_reserve_fences(bo->base.resv, 1);
 	if (!ret)
 		dma_resv_add_fence(bo->base.resv, &fence->base,
-				   DMA_RESV_USAGE_WRITE);
+				   DMA_RESV_USAGE_KERNEL);
 	else
 		/* Last resort fallback when we are OOM */
 		dma_fence_wait(&fence->base, false);
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
index 39081dbf9ac8..f999fdd927df 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_resource.c
@@ -1167,7 +1167,7 @@ int vmw_resources_clean(struct vmw_buffer_object *vbo, pgoff_t start,
 			dma_fence_put(bo->moving);
 
 		return dma_resv_get_singleton(bo->base.resv,
-					      DMA_RESV_USAGE_WRITE,
+					      DMA_RESV_USAGE_KERNEL,
 					      &bo->moving);
 	}
 
diff --git a/drivers/infiniband/core/umem_dmabuf.c b/drivers/infiniband/core/umem_dmabuf.c
index f9901d273b8e..fce80a4a5147 100644
--- a/drivers/infiniband/core/umem_dmabuf.c
+++ b/drivers/infiniband/core/umem_dmabuf.c
@@ -68,7 +68,7 @@ int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
 	 * the migration.
 	 */
 	return dma_resv_wait_timeout(umem_dmabuf->attach->dmabuf->resv,
-				     DMA_RESV_USAGE_WRITE,
+				     DMA_RESV_USAGE_KERNEL,
 				     false, MAX_SCHEDULE_TIMEOUT);
 }
 EXPORT_SYMBOL(ib_umem_dmabuf_map_pages);
diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h
index ae0436d7e7b8..543e25d5116a 100644
--- a/include/linux/dma-resv.h
+++ b/include/linux/dma-resv.h
@@ -54,8 +54,30 @@ struct dma_resv_list;
  *
  * This enum describes the different use cases for a dma_resv object and
  * controls which fences are returned when queried.
+ *
+ * An important fact is that there is the order KERNEL<WRITE<READ and
+ * when the dma_resv object is asked for fences for one use case the fences
+ * for the lower use case are returned as well.
+ *
+ * For example when asking for WRITE fences then the KERNEL fences are returned
+ * as well. Similar when asked for READ fences then both WRITE and KERNEL
+ * fences are returned as well.
  */
 enum dma_resv_usage {
+	/**
+	 * @DMA_RESV_USAGE_KERNEL: For in kernel memory management only.
+	 *
+	 * This should only be used for things like copying or clearing memory
+	 * with a DMA hardware engine for the purpose of kernel memory
+	 * management.
+	 *
+         * Drivers *always* need to wait for those fences before accessing the
+	 * resource protected by the dma_resv object. The only exception for
+	 * that is when the resource is known to be locked down in place by
+	 * pinning it previously.
+	 */
+	DMA_RESV_USAGE_KERNEL,
+
 	/**
 	 * @DMA_RESV_USAGE_WRITE: Implicit write synchronization.
 	 *
-- 
2.25.1