I think we should do it differently because this interface will be mostly unused by open source userspace in its current form.

Let's set the workload hint in drm_amdgpu_ctx_in::flags, and that will be immutable for the lifetime of the context. No other interface is needed.

Marek

On Mon, Sep 26, 2022 at 5:41 PM Shashank Sharma <shashank.sharma@amd.com> wrote:
Allow the user to specify a workload hint to the kernel.
We can use these to tweak the dpm heuristics to better match
the workload for improved performance.

V3: Create only set() workload UAPI (Christian)

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Shashank Sharma <shashank.sharma@amd.com>
---
 include/uapi/drm/amdgpu_drm.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
index c2c9c674a223..23d354242699 100644
--- a/include/uapi/drm/amdgpu_drm.h
+++ b/include/uapi/drm/amdgpu_drm.h
@@ -212,6 +212,7 @@ union drm_amdgpu_bo_list {
 #define AMDGPU_CTX_OP_QUERY_STATE2     4
 #define AMDGPU_CTX_OP_GET_STABLE_PSTATE        5
 #define AMDGPU_CTX_OP_SET_STABLE_PSTATE        6
+#define AMDGPU_CTX_OP_SET_WORKLOAD_PROFILE     7

 /* GPU reset status */
 #define AMDGPU_CTX_NO_RESET            0
@@ -252,6 +253,17 @@ union drm_amdgpu_bo_list {
 #define AMDGPU_CTX_STABLE_PSTATE_MIN_MCLK  3
 #define AMDGPU_CTX_STABLE_PSTATE_PEAK  4

+/* GPU workload hints, flag bits 8-15 */
+#define AMDGPU_CTX_WORKLOAD_HINT_SHIFT     8
+#define AMDGPU_CTX_WORKLOAD_HINT_MASK      (0xff << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_NONE      (0 << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_3D        (1 << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_VIDEO     (2 << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_VR        (3 << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_COMPUTE   (4 << AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+#define AMDGPU_CTX_WORKLOAD_HINT_MAX      AMDGPU_CTX_WORKLOAD_HINT_COMPUTE
+#define AMDGPU_CTX_WORKLOAD_INDEX(n)      (n >> AMDGPU_CTX_WORKLOAD_HINT_SHIFT)
+
 struct drm_amdgpu_ctx_in {
        /** AMDGPU_CTX_OP_* */
        __u32   op;
@@ -281,6 +293,11 @@ union drm_amdgpu_ctx_out {
                        __u32   flags;
                        __u32   _pad;
                } pstate;
+
+               struct {
+                       __u32   flags;
+                       __u32   _pad;
+               } workload;
 };

 union drm_amdgpu_ctx {
--
2.34.1