[PATCH libdrm] amdgpu: Add context priority override function.

[Samuel Pitoiset]

Reviewed-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>

On 4/17/19 8:33 PM, Bas Nieuwenhuizen wrote:
> This way we can override the priority of a single context using a
> master fd.
>
> Since we cannot usefully create an amdgpu device of a master fd
> without the fd deduplication kicking in this takes a plain fd.
>
> This can be used by e.g. radv to get high priority contexts using
> a master fd from the primary node or a lease.
> ---
>   amdgpu/amdgpu-symbol-check |  1 +
>   amdgpu/amdgpu.h            | 15 +++++++++++++++
>   amdgpu/amdgpu_cs.c         | 25 +++++++++++++++++++++++++
>   3 files changed, 41 insertions(+)
>
> diff --git a/amdgpu/amdgpu-symbol-check b/amdgpu/amdgpu-symbol-check
> index 96a44b40..4d806922 100755
> --- a/amdgpu/amdgpu-symbol-check
> +++ b/amdgpu/amdgpu-symbol-check
> @@ -38,6 +38,7 @@ amdgpu_cs_create_syncobj2
>   amdgpu_cs_ctx_create
>   amdgpu_cs_ctx_create2
>   amdgpu_cs_ctx_free
> +amdgpu_cs_ctx_override_priority
>   amdgpu_cs_destroy_semaphore
>   amdgpu_cs_destroy_syncobj
>   amdgpu_cs_export_syncobj
> diff --git a/amdgpu/amdgpu.h b/amdgpu/amdgpu.h
> index d6de3b8d..3d838e08 100644
> --- a/amdgpu/amdgpu.h
> +++ b/amdgpu/amdgpu.h
> @@ -911,6 +911,21 @@ int amdgpu_cs_ctx_create(amdgpu_device_handle dev,
>   */
>   int amdgpu_cs_ctx_free(amdgpu_context_handle context);
>   
> +/**
> + * Override the submission priority for the given context using a master fd.
> + *
> + * \param   dev	       - \c [in] device handle
> + * \param   context    - \c [in] context handle for context id
> + * \param   master_fd  - \c [in] The master fd to authorize the override.
> + * \param   priority   - \c [in] The priority to assign to the context.
> + *
> + * \return 0 on success or a a negative Posix error code on failure.
> + */
> +int amdgpu_cs_ctx_override_priority(amdgpu_device_handle dev,
> +                                    amdgpu_context_handle context,
> +                                    int master_fd,
> +                                    unsigned priority);
> +
>   /**
>    * Query reset state for the specific GPU Context
>    *
> diff --git a/amdgpu/amdgpu_cs.c b/amdgpu/amdgpu_cs.c
> index 5bedf748..7ee844fb 100644
> --- a/amdgpu/amdgpu_cs.c
> +++ b/amdgpu/amdgpu_cs.c
> @@ -142,6 +142,31 @@ drm_public int amdgpu_cs_ctx_free(amdgpu_context_handle context)
>   	return r;
>   }
>   
> +drm_public int amdgpu_cs_ctx_override_priority(amdgpu_device_handle dev,
> +                                               amdgpu_context_handle context,
> +                                               int master_fd,
> +                                               unsigned priority)
> +{
> +	int r;
> +
> +	if (!dev || !context || master_fd < 0)
> +		return -EINVAL;
> +
> +	union drm_amdgpu_sched args;
> +	memset(&args, 0, sizeof(args));
> +
> +	args.in.op = AMDGPU_SCHED_OP_CONTEXT_PRIORITY_OVERRIDE;
> +	args.in.fd = dev->fd;
> +	args.in.priority = priority;
> +	args.in.ctx_id = context->id;
> +
> +	r = drmCommandWrite(master_fd, DRM_AMDGPU_SCHED, &args, sizeof(args));
> +	if (r)
> +		return r;
> +
> +	return 0;
> +}
> +
>   drm_public int amdgpu_cs_query_reset_state(amdgpu_context_handle context,
>   					   uint32_t *state, uint32_t *hangs)
>   {