drm/i915: Move GEM object domain management from struct_mutex to local

Use the per-object local lock to control the cache domain of the
individual GEM objects, not struct_mutex. This is a huge leap forward
for us in terms of object-level synchronisation; execbuffers are
coordinated using the ww_mutex and pread/pwrite is finally fully
serialised again.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528092956.14910-10-chris@chris-wilson.co.uk

1 files changed, 16 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index 80dcd879fc58..a2ac06a08715 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -765,8 +765,10 @@ static int intel_overlay_do_put_image(struct intel_overlay *overlay,
 
 	atomic_inc(&dev_priv->gpu_error.pending_fb_pin);
 
+	i915_gem_object_lock(new_bo);
 	vma = i915_gem_object_pin_to_display_plane(new_bo,
 						   0, NULL, PIN_MAPPABLE);
+	i915_gem_object_unlock(new_bo);
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
 		goto out_pin_section;
@@ -1305,15 +1307,20 @@ out_unlock:
 
 static int get_registers(struct intel_overlay *overlay, bool use_phys)
 {
+	struct drm_i915_private *i915 = overlay->i915;
 	struct drm_i915_gem_object *obj;
 	struct i915_vma *vma;
 	int err;
 
-	obj = i915_gem_object_create_stolen(overlay->i915, PAGE_SIZE);
+	mutex_lock(&i915->drm.struct_mutex);
+
+	obj = i915_gem_object_create_stolen(i915, PAGE_SIZE);
 	if (obj == NULL)
-		obj = i915_gem_object_create_internal(overlay->i915, PAGE_SIZE);
-	if (IS_ERR(obj))
-		return PTR_ERR(obj);
+		obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
+	if (IS_ERR(obj)) {
+		err = PTR_ERR(obj);
+		goto err_unlock;
+	}
 
 	vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, PIN_MAPPABLE);
 	if (IS_ERR(vma)) {
@@ -1334,10 +1341,13 @@ static int get_registers(struct intel_overlay *overlay, bool use_phys)
 	}
 
 	overlay->reg_bo = obj;
+	mutex_unlock(&i915->drm.struct_mutex);
 	return 0;
 
 err_put_bo:
 	i915_gem_object_put(obj);
+err_unlock:
+	mutex_unlock(&i915->drm.struct_mutex);
 	return err;
 }
 
@@ -1363,18 +1373,16 @@ void intel_overlay_setup(struct drm_i915_private *dev_priv)
 
 	INIT_ACTIVE_REQUEST(&overlay->last_flip);
 
-	mutex_lock(&dev_priv->drm.struct_mutex);
-
 	ret = get_registers(overlay, OVERLAY_NEEDS_PHYSICAL(dev_priv));
 	if (ret)
 		goto out_free;
 
+	i915_gem_object_lock(overlay->reg_bo);
 	ret = i915_gem_object_set_to_gtt_domain(overlay->reg_bo, true);
+	i915_gem_object_unlock(overlay->reg_bo);
 	if (ret)
 		goto out_reg_bo;
 
-	mutex_unlock(&dev_priv->drm.struct_mutex);
-
 	memset_io(overlay->regs, 0, sizeof(struct overlay_registers));
 	update_polyphase_filter(overlay->regs);
 	update_reg_attrs(overlay, overlay->regs);
@@ -1386,7 +1394,6 @@ void intel_overlay_setup(struct drm_i915_private *dev_priv)
 out_reg_bo:
 	i915_gem_object_put(overlay->reg_bo);
 out_free:
-	mutex_unlock(&dev_priv->drm.struct_mutex);
 	kfree(overlay);
 }