[Intel-gfx] [PATCH v3 09/14] drm/i915: Store the execution priority on the context

[Chris Wilson]

In order to support userspace defining different levels of importance to
different contexts, and in particular the preferred order of execution,
store a priority value on each context. By default, the kernel's
context, which is used for idling and other background tasks, is given
minimum priority (all user contexts will execute first).

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_drv.h         | 1 +
 drivers/gpu/drm/i915/i915_gem_context.c | 1 +
 drivers/gpu/drm/i915/i915_gem_request.c | 2 +-
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index ab4ad5522cf5..fb3e850f5d3a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -936,6 +936,7 @@ struct i915_gem_context {
 	/* Unique identifier for this context, used by the hw for tracking */
 	unsigned int hw_id;
 	u32 user_handle;
+	int priority; /* greater priorities are serviced first */
 
 	u32 ggtt_alignment;
 
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 6dd475735f0a..1f94b8d6d83d 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -476,6 +476,7 @@ int i915_gem_context_init(struct drm_device *dev)
 		return PTR_ERR(ctx);
 	}
 
+	ctx->priority = I915_PRIORITY_MIN; /* lowest priority; idle task */
 	dev_priv->kernel_context = ctx;
 
 	DRM_DEBUG_DRIVER("%s context support initialized\n",
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 13574a1e29b1..b9b5253cf3cd 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -867,7 +867,7 @@ void __i915_add_request(struct drm_i915_gem_request *request, bool flush_caches)
 	 * run at the earliest possible convenience.
 	 */
 	if (engine->schedule)
-		engine->schedule(request, 0);
+		engine->schedule(request, request->ctx->priority);
 
 	local_bh_disable();
 	i915_sw_fence_commit(&request->submit);
-- 
2.10.2