[PATCH 2/2] drm/amdgpu: add new bo flag that indicates BOs don't need fallback

[Chunming Zhou]

user cases:
1. KFD wraps amdgpu_bo_create, they have no fallback case which is different
with amdgpu_gem_object_create.
since upstream branch has no amdgpu_amdkfd_gpuvm.c, which need KFD
guys add this flag to __alloc_memory_of_gpu:
+       flags |= AMDGPU_GEM_CREATE_NO_FALLBACK;
2. UMD can specify this flag for their allocation as well if they like.

Change-Id: Id3ac1a0bdd48633328d0b22c4c057fab4e94d0b3
Signed-off-by: Chunming Zhou <david1.zhou at amd.com>
Cc: felix.kuehling at amd.com
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c     | 3 ++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 3 ++-
 include/uapi/drm/amdgpu_drm.h              | 2 ++
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index dc34b50e6b29..d7d7ce1507ec 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -386,7 +386,8 @@ static int amdgpu_cs_bo_validate(struct amdgpu_cs_parser *p,
 	    bo->tbo.mem.start < adev->gmc.visible_vram_size >> PAGE_SHIFT)
 		p->bytes_moved_vis += ctx.bytes_moved;
 
-	if (unlikely(r == -ENOMEM) && domain != bo->allowed_domains) {
+	if (unlikely(r == -ENOMEM) && domain != bo->allowed_domains &&
+	    !(bo->flags & AMDGPU_GEM_CREATE_NO_FALLBACK)) {
 		domain = bo->allowed_domains;
 		goto retry;
 	}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index f04bfab1eebd..c70d745073b8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -420,7 +420,8 @@ static int amdgpu_bo_do_create(struct amdgpu_device *adev, unsigned long size,
 	r = ttm_bo_init_reserved(&adev->mman.bdev, &bo->tbo, size, type,
 				 &bo->placement, page_align, &ctx, acc_size,
 				 NULL, resv, &amdgpu_ttm_bo_destroy);
-	if (unlikely(r && r != -ERESTARTSYS) && type == ttm_bo_type_device) {
+	if (unlikely(r && r != -ERESTARTSYS) && type == ttm_bo_type_device &&
+	    !(flags & AMDGPU_GEM_CREATE_NO_FALLBACK)) {
 		if (flags & AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED) {
 			flags &= ~AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
 			goto retry;
diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
index 0087799962cf..80665715e651 100644
--- a/include/uapi/drm/amdgpu_drm.h
+++ b/include/uapi/drm/amdgpu_drm.h
@@ -98,6 +98,8 @@ extern "C" {
 #define AMDGPU_GEM_CREATE_VM_ALWAYS_VALID	(1 << 6)
 /* Flag that BO sharing will be explicitly synchronized */
 #define AMDGPU_GEM_CREATE_EXPLICIT_SYNC		(1 << 7)
+/* Flag that BO doesn't need fallback */
+#define AMDGPU_GEM_CREATE_NO_FALLBACK		(1 << 8)
 
 struct drm_amdgpu_gem_create_in  {
 	/** the requested memory size */
-- 
2.14.1