[PATCH 10/11] drm/i915: Introduce context->enter() and context->exit()

[Chris Wilson]

We wish to start segregating the power management into different control
domains, both with respect to the hardware and the user interface. The
first step is that at the lowest level flow of requests, we want to
process a context event (and not a global GEM operation). In this patch,
we introduce the context callbacks that in future patches will be
redirected to per-engine interfaces leading to global operations as
required.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_context.c       | 19 ++++++++++++++++
 drivers/gpu/drm/i915/gt/intel_context.h       | 13 +++++++++++
 drivers/gpu/drm/i915/gt/intel_context_types.h |  3 +++
 drivers/gpu/drm/i915/gt/intel_lrc.c           |  3 +++
 drivers/gpu/drm/i915/gt/intel_ringbuffer.c    |  3 +++
 drivers/gpu/drm/i915/i915_request.c           | 22 ++++---------------
 6 files changed, 45 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index ebd1e5919a4a..4681f294a897 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -266,3 +266,22 @@ int __init i915_global_context_init(void)
 	i915_global_register(&global.base);
 	return 0;
 }
+
+int __intel_context_enter(struct intel_context *ce)
+{
+	struct drm_i915_private *i915 = ce->gem_context->i915;
+
+	if (!i915->gt.active_requests++)
+		i915_gem_unpark(i915);
+
+	return 0;
+}
+
+void __intel_context_exit(struct intel_context *ce)
+{
+	struct drm_i915_private *i915 = ce->gem_context->i915;
+
+	GEM_BUG_ON(!i915->gt.active_requests);
+	if (!--i915->gt.active_requests)
+		i915_gem_park(i915);
+}
diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index ebc861b1a49e..a9a2810d9389 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -73,6 +73,19 @@ static inline void __intel_context_pin(struct intel_context *ce)
 
 void intel_context_unpin(struct intel_context *ce);
 
+int __intel_context_enter(struct intel_context *ce);
+void __intel_context_exit(struct intel_context *ce);
+
+static inline int intel_context_enter(struct intel_context *ce)
+{
+	return ce->ops->enter(ce);
+}
+
+static inline void intel_context_exit(struct intel_context *ce)
+{
+	return ce->ops->exit(ce);
+}
+
 static inline struct intel_context *intel_context_get(struct intel_context *ce)
 {
 	kref_get(&ce->ref);
diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index 9ec4f787c908..eb9505cf06a4 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -25,6 +25,9 @@ struct intel_context_ops {
 	int (*pin)(struct intel_context *ce);
 	void (*unpin)(struct intel_context *ce);
 
+	int (*enter)(struct intel_context *ce);
+	void (*exit)(struct intel_context *ce);
+
 	void (*reset)(struct intel_context *ce);
 	void (*destroy)(struct kref *kref);
 };
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 23c400e44fb8..af4f29a4dd2d 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1404,6 +1404,9 @@ static const struct intel_context_ops execlists_context_ops = {
 	.pin = execlists_context_pin,
 	.unpin = execlists_context_unpin,
 
+	.enter = __intel_context_enter,
+	.exit = __intel_context_exit,
+
 	.reset = execlists_context_reset,
 	.destroy = execlists_context_destroy,
 };
diff --git a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
index bcc842b8bbe7..5788e5ab818f 100644
--- a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
@@ -1516,6 +1516,9 @@ static const struct intel_context_ops ring_context_ops = {
 	.pin = ring_context_pin,
 	.unpin = ring_context_unpin,
 
+	.enter = __intel_context_enter,
+	.exit = __intel_context_exit,
+
 	.reset = ring_context_reset,
 	.destroy = ring_context_destroy,
 };
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index b74711bc3279..ab170affd266 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -129,19 +129,6 @@ i915_request_remove_from_client(struct i915_request *request)
 	spin_unlock(&file_priv->mm.lock);
 }
 
-static void reserve_gt(struct drm_i915_private *i915)
-{
-	if (!i915->gt.active_requests++)
-		i915_gem_unpark(i915);
-}
-
-static void unreserve_gt(struct drm_i915_private *i915)
-{
-	GEM_BUG_ON(!i915->gt.active_requests);
-	if (!--i915->gt.active_requests)
-		i915_gem_park(i915);
-}
-
 static void advance_ring(struct i915_request *request)
 {
 	struct intel_ring *ring = request->ring;
@@ -299,11 +286,10 @@ static void i915_request_retire(struct i915_request *request)
 
 	i915_request_remove_from_client(request);
 
-	intel_context_unpin(request->hw_context);
-
 	__retire_engine_upto(request->engine, request);
 
-	unreserve_gt(request->i915);
+	intel_context_unpin(request->hw_context);
+	intel_context_exit(request->hw_context);
 
 	i915_sched_node_fini(&request->sched);
 	i915_request_put(request);
@@ -632,7 +618,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	if (IS_ERR(ce))
 		return ERR_CAST(ce);
 
-	reserve_gt(i915);
+	intel_context_enter(ce);
 	mutex_lock(&ce->ring->timeline->mutex);
 
 	/* Move our oldest request to the slab-cache (if not in use!) */
@@ -768,7 +754,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	kmem_cache_free(global.slab_requests, rq);
 err_unreserve:
 	mutex_unlock(&ce->ring->timeline->mutex);
-	unreserve_gt(i915);
+	intel_context_exit(ce);
 	intel_context_unpin(ce);
 	return ERR_PTR(ret);
 }
-- 
2.20.1