[Intel-gfx] [PATCH v2 6/6] drm/i915/execlists: Don't allocate scratch

[Michał Winiarski]

We're no longer using it on execlists platforms. There's no point in
allocating it.

v2: Move scratch init to legacy ring submission backend. (Chris)

Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_engine_cs.c  |  2 --
 drivers/gpu/drm/i915/gt/intel_gt.c         | 17 +++++------------
 drivers/gpu/drm/i915/gt/intel_gt.h         |  2 +-
 drivers/gpu/drm/i915/gt/intel_ringbuffer.c |  5 +++++
 drivers/gpu/drm/i915/i915_gem.c            |  2 --
 5 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index f451d5076bde..a4e5aceff678 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -669,8 +669,6 @@ static int measure_breadcrumb_dw(struct intel_engine_cs *engine)
 	struct measure_breadcrumb *frame;
 	int dw = -ENOMEM;
 
-	GEM_BUG_ON(!engine->gt->scratch);
-
 	frame = kzalloc(sizeof(*frame), GFP_KERNEL);
 	if (!frame)
 		return -ENOMEM;
diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index eef9bdae8ebb..e67a6cabc81d 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -322,13 +322,17 @@ void intel_gt_driver_register(struct intel_gt *gt)
 		intel_gpu_ips_init(gt->i915);
 }
 
-static int intel_gt_init_scratch(struct intel_gt *gt, unsigned int size)
+int intel_gt_init_scratch(struct intel_gt *gt, unsigned int size)
 {
 	struct drm_i915_private *i915 = gt->i915;
 	struct drm_i915_gem_object *obj;
 	struct i915_vma *vma;
 	int ret;
 
+	/* Created lazily - submission backend calls us at its init time */
+	if (gt->scratch)
+		return 0;
+
 	obj = i915_gem_object_create_stolen(i915, size);
 	if (!obj)
 		obj = i915_gem_object_create_internal(i915, size);
@@ -361,17 +365,6 @@ static void intel_gt_fini_scratch(struct intel_gt *gt)
 	i915_vma_unpin_and_release(&gt->scratch, 0);
 }
 
-int intel_gt_init(struct intel_gt *gt)
-{
-	int err;
-
-	err = intel_gt_init_scratch(gt, IS_GEN(gt->i915, 2) ? SZ_256K : SZ_4K);
-	if (err)
-		return err;
-
-	return 0;
-}
-
 void intel_gt_driver_remove(struct intel_gt *gt)
 {
 	GEM_BUG_ON(gt->awake);
diff --git a/drivers/gpu/drm/i915/gt/intel_gt.h b/drivers/gpu/drm/i915/gt/intel_gt.h
index e6ab0bff0efb..b9ed8ea3706e 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt.h
@@ -30,7 +30,7 @@ static inline struct intel_gt *huc_to_gt(struct intel_huc *huc)
 void intel_gt_init_early(struct intel_gt *gt, struct drm_i915_private *i915);
 void intel_gt_init_hw_early(struct drm_i915_private *i915);
 int __must_check intel_gt_init_hw(struct intel_gt *gt);
-int intel_gt_init(struct intel_gt *gt);
+int intel_gt_init_scratch(struct intel_gt *gt, unsigned int size);
 void intel_gt_driver_register(struct intel_gt *gt);
 
 void intel_gt_driver_unregister(struct intel_gt *gt);
diff --git a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
index 0747b8c9f768..64d22239df8a 100644
--- a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
@@ -2315,6 +2315,11 @@ int intel_ring_submission_init(struct intel_engine_cs *engine)
 	struct intel_ring *ring;
 	int err;
 
+	err = intel_gt_init_scratch(engine->gt,
+				    IS_GEN(engine->i915, 2) ? SZ_256K : SZ_4K);
+	if (err)
+		goto err;
+
 	timeline = intel_timeline_create(engine->gt, engine->status_page.vma);
 	if (IS_ERR(timeline)) {
 		err = PTR_ERR(timeline);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e2897a666225..09d387f4d46b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1337,8 +1337,6 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
 		goto err_unlock;
 	}
 
-	intel_gt_init(&dev_priv->gt);
-
 	ret = intel_engines_setup(dev_priv);
 	if (ret) {
 		GEM_BUG_ON(ret == -EIO);
-- 
2.21.0