[PATCH v3] drm/amdgpu: Add AMDGPU_CHUNK_ID_SCHEDULED_DEPENDENCIES

[Koenig, Christian]

Am 01.02.19 um 22:41 schrieb Andrey Grodzovsky:
> New chunk for dependency on start of job's execution instead on
> the end. This is used for GPU deadlock prevention when
> userspace uses mid-IB fences to wait for mid-IB work on other rings.
>
> v2: Fix typo in AMDGPU_CHUNK_ID_SCHEDULED_DEPENDENCIES
> v3: Bump KMS version
>
> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
> Suggested-by: Christian Koenig <Christian.Koenig at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c  | 12 +++++++++++-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c |  3 ++-
>   include/uapi/drm/amdgpu_drm.h           |  1 +
>   3 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> index 1c49b82..3f21eca 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> @@ -214,6 +214,7 @@ static int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, union drm_amdgpu_cs
>   		case AMDGPU_CHUNK_ID_DEPENDENCIES:
>   		case AMDGPU_CHUNK_ID_SYNCOBJ_IN:
>   		case AMDGPU_CHUNK_ID_SYNCOBJ_OUT:
> +		case AMDGPU_CHUNK_ID_SCHEDULED_DEPENDENCIES:
>   			break;
>   
>   		default:
> @@ -1090,6 +1091,14 @@ static int amdgpu_cs_process_fence_dep(struct amdgpu_cs_parser *p,
>   
>   		fence = amdgpu_ctx_get_fence(ctx, entity,
>   					     deps[i].handle);
> +
> +		if (chunk->chunk_id == AMDGPU_CHUNK_ID_SCHEDULED_DEPENDENCIES) {
> +			struct drm_sched_fence *s_fence = to_drm_sched_fence(fence);
> +
> +			dma_fence_put(fence);
> +			fence = dma_fence_get(&s_fence->scheduled);

You need to change the order here or otherwise the dma_fence_put could 
destroy the fence we want.

Apart from that looks really good to me,
Christian.

> +		}
> +
>   		if (IS_ERR(fence)) {
>   			r = PTR_ERR(fence);
>   			amdgpu_ctx_put(ctx);
> @@ -1177,7 +1186,8 @@ static int amdgpu_cs_dependencies(struct amdgpu_device *adev,
>   
>   		chunk = &p->chunks[i];
>   
> -		if (chunk->chunk_id == AMDGPU_CHUNK_ID_DEPENDENCIES) {
> +		if (chunk->chunk_id == AMDGPU_CHUNK_ID_DEPENDENCIES ||
> +		    chunk->chunk_id == AMDGPU_CHUNK_ID_SCHEDULED_DEPENDENCIES) {
>   			r = amdgpu_cs_process_fence_dep(p, chunk);
>   			if (r)
>   				return r;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index c806f98..1158a6f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -71,9 +71,10 @@
>    * - 3.25.0 - Add support for sensor query info (stable pstate sclk/mclk).
>    * - 3.26.0 - GFX9: Process AMDGPU_IB_FLAG_TC_WB_NOT_INVALIDATE.
>    * - 3.27.0 - Add new chunk to to AMDGPU_CS to enable BO_LIST creation.
> + * - 3.28.0 - Add AMDGPU_CHUNK_ID_SCHEDULED_DEPENDENCIES
>    */
>   #define KMS_DRIVER_MAJOR	3
> -#define KMS_DRIVER_MINOR	27
> +#define KMS_DRIVER_MINOR	28
>   #define KMS_DRIVER_PATCHLEVEL	0
>   
>   int amdgpu_vram_limit = 0;
> diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
> index faaad04..43d03a2 100644
> --- a/include/uapi/drm/amdgpu_drm.h
> +++ b/include/uapi/drm/amdgpu_drm.h
> @@ -526,6 +526,7 @@ struct drm_amdgpu_gem_va {
>   #define AMDGPU_CHUNK_ID_SYNCOBJ_IN      0x04
>   #define AMDGPU_CHUNK_ID_SYNCOBJ_OUT     0x05
>   #define AMDGPU_CHUNK_ID_BO_HANDLES      0x06
> +#define AMDGPU_CHUNK_ID_SCHEDULED_DEPENDENCIES	0x07
>   
>   struct drm_amdgpu_cs_chunk {
>   	__u32		chunk_id;