drm/amdgpu: Add command to override the context priority.

Given a master fd we can then override the priority of the context
in another fd.

Using these overrides was recommended by Christian instead of trying
to submit from a master fd, and I am adding a way to override a
single context instead of the entire process so we can only upgrade
a single Vulkan queue and not effectively the entire process.

Reused the flags field as it was checked to be 0 anyways, so nothing
used it. This is source-incompatible (due to the name change), but
ABI compatible.
Signed-off-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c

@@ -76,6 +76,39 @@ static int amdgpu_sched_process_priority_override(struct amdgpu_device *adev,
 	return 0;
 }
 
+static int amdgpu_sched_context_priority_override(struct amdgpu_device *adev,
+						  int fd,
+						  unsigned ctx_id,
+						  enum drm_sched_priority priority)
+{
+	struct file *filp = fget(fd);
+	struct amdgpu_fpriv *fpriv;
+	struct amdgpu_ctx *ctx;
+	int r;
+
+	if (!filp)
+		return -EINVAL;
+
+	r = amdgpu_file_to_fpriv(filp, &fpriv);
+	if (r) {
+		fput(filp);
+		return r;
+	}
+
+	ctx = amdgpu_ctx_get(fpriv, ctx_id);
+
+	if (!ctx) {
+		fput(filp);
+		return -EINVAL;
+	}
+
+	amdgpu_ctx_priority_override(ctx, priority);
+	amdgpu_ctx_put(ctx);
+	fput(filp);
+
+	return 0;
+}
+
 int amdgpu_sched_ioctl(struct drm_device *dev, void *data,
 		       struct drm_file *filp)
 {
@@ -85,7 +118,7 @@ int amdgpu_sched_ioctl(struct drm_device *dev, void *data,
 	int r;
 
 	priority = amdgpu_to_sched_priority(args->in.priority);
-	if (args->in.flags || priority == DRM_SCHED_PRIORITY_INVALID)
+	if (priority == DRM_SCHED_PRIORITY_INVALID)
 		return -EINVAL;
 
 	switch (args->in.op) {
@@ -94,6 +127,12 @@ int amdgpu_sched_ioctl(struct drm_device *dev, void *data,
 							   args->in.fd,
 							   priority);
 		break;
+	case AMDGPU_SCHED_OP_CONTEXT_PRIORITY_OVERRIDE:
+		r = amdgpu_sched_context_priority_override(adev,
+							   args->in.fd,
+							   args->in.ctx_id,
+							   priority);
+		break;
 	default:
 		DRM_ERROR("Invalid sched op specified: %d\n", args->in.op);
 		r = -EINVAL;

include/uapi/drm/amdgpu_drm.h

@@ -272,13 +272,14 @@ union drm_amdgpu_vm {
 
 /* sched ioctl */
 #define AMDGPU_SCHED_OP_PROCESS_PRIORITY_OVERRIDE	1
+#define AMDGPU_SCHED_OP_CONTEXT_PRIORITY_OVERRIDE	2
 
 struct drm_amdgpu_sched_in {
 	/* AMDGPU_SCHED_OP_* */
 	__u32	op;
 	__u32	fd;
 	__s32	priority;
-	__u32	flags;
+	__u32   ctx_id;
 };
 
 union drm_amdgpu_sched {