drm/i915/overlay: Switch to using i915_active tracking

Remove the raw i915_active_request tracking in favour of the higher
level i915_active tracking for the sole purpose of making the lockless
transition easier in later patches.
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/20190812174804.26180-2-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/display/intel_overlay.c

@@ -191,7 +191,8 @@ struct intel_overlay {
 	struct overlay_registers __iomem *regs;
 	u32 flip_addr;
 	/* flip handling */
-	struct i915_active_request last_flip;
+	struct i915_active last_flip;
+	void (*flip_complete)(struct intel_overlay *ovl);
 };
 
 static void i830_overlay_clock_gating(struct drm_i915_private *dev_priv,
@@ -217,30 +218,25 @@ static void i830_overlay_clock_gating(struct drm_i915_private *dev_priv,
 				  PCI_DEVFN(0, 0), I830_CLOCK_GATE, val);
 }
 
-static void intel_overlay_submit_request(struct intel_overlay *overlay,
-					 struct i915_request *rq,
-					 i915_active_retire_fn retire)
+static struct i915_request *
+alloc_request(struct intel_overlay *overlay, void (*fn)(struct intel_overlay *))
 {
-	GEM_BUG_ON(i915_active_request_peek(&overlay->last_flip,
-					    &overlay->i915->drm.struct_mutex));
-	i915_active_request_set_retire_fn(&overlay->last_flip, retire,
-					  &overlay->i915->drm.struct_mutex);
-	__i915_active_request_set(&overlay->last_flip, rq);
-	i915_request_add(rq);
-}
+	struct i915_request *rq;
+	int err;
 
-static int intel_overlay_do_wait_request(struct intel_overlay *overlay,
-					 struct i915_request *rq,
-					 i915_active_retire_fn retire)
-{
-	intel_overlay_submit_request(overlay, rq, retire);
-	return i915_active_request_retire(&overlay->last_flip,
-					  &overlay->i915->drm.struct_mutex);
-}
+	overlay->flip_complete = fn;
 
-static struct i915_request *alloc_request(struct intel_overlay *overlay)
-{
-	return i915_request_create(overlay->context);
+	rq = i915_request_create(overlay->context);
+	if (IS_ERR(rq))
+		return rq;
+
+	err = i915_active_ref(&overlay->last_flip, rq->fence.context, rq);
+	if (err) {
+		i915_request_add(rq);
+		return ERR_PTR(err);
+	}
+
+	return rq;
 }
 
 /* overlay needs to be disable in OCMD reg */
@@ -252,7 +248,7 @@ static int intel_overlay_on(struct intel_overlay *overlay)
 
 	WARN_ON(overlay->active);
 
-	rq = alloc_request(overlay);
+	rq = alloc_request(overlay, NULL);
 	if (IS_ERR(rq))
 		return PTR_ERR(rq);
 
@@ -273,7 +269,9 @@ static int intel_overlay_on(struct intel_overlay *overlay)
 	*cs++ = MI_NOOP;
 	intel_ring_advance(rq, cs);
 
-	return intel_overlay_do_wait_request(overlay, rq, NULL);
+	i915_request_add(rq);
+
+	return i915_active_wait(&overlay->last_flip);
 }
 
 static void intel_overlay_flip_prepare(struct intel_overlay *overlay,
@@ -317,7 +315,7 @@ static int intel_overlay_continue(struct intel_overlay *overlay,
 	if (tmp & (1 << 17))
 		DRM_DEBUG("overlay underrun, DOVSTA: %x\n", tmp);
 
-	rq = alloc_request(overlay);
+	rq = alloc_request(overlay, NULL);
 	if (IS_ERR(rq))
 		return PTR_ERR(rq);
 
@@ -332,8 +330,7 @@ static int intel_overlay_continue(struct intel_overlay *overlay,
 	intel_ring_advance(rq, cs);
 
 	intel_overlay_flip_prepare(overlay, vma);
-
-	intel_overlay_submit_request(overlay, rq, NULL);
+	i915_request_add(rq);
 
 	return 0;
 }
@@ -354,20 +351,13 @@ static void intel_overlay_release_old_vma(struct intel_overlay *overlay)
 }
 
 static void
-intel_overlay_release_old_vid_tail(struct i915_active_request *active,
-				   struct i915_request *rq)
+intel_overlay_release_old_vid_tail(struct intel_overlay *overlay)
 {
-	struct intel_overlay *overlay =
-		container_of(active, typeof(*overlay), last_flip);
-
 	intel_overlay_release_old_vma(overlay);
 }
 
-static void intel_overlay_off_tail(struct i915_active_request *active,
-				   struct i915_request *rq)
+static void intel_overlay_off_tail(struct intel_overlay *overlay)
 {
-	struct intel_overlay *overlay =
-		container_of(active, typeof(*overlay), last_flip);
 	struct drm_i915_private *dev_priv = overlay->i915;
 
 	intel_overlay_release_old_vma(overlay);
@@ -380,6 +370,16 @@ static void intel_overlay_off_tail(struct i915_active_request *active,
 		i830_overlay_clock_gating(dev_priv, true);
 }
 
+static void
+intel_overlay_last_flip_retire(struct i915_active *active)
+{
+	struct intel_overlay *overlay =
+		container_of(active, typeof(*overlay), last_flip);
+
+	if (overlay->flip_complete)
+		overlay->flip_complete(overlay);
+}
+
 /* overlay needs to be disabled in OCMD reg */
 static int intel_overlay_off(struct intel_overlay *overlay)
 {
@@ -394,7 +394,7 @@ static int intel_overlay_off(struct intel_overlay *overlay)
 	 * of the hw. Do it in both cases */
 	flip_addr |= OFC_UPDATE;
 
-	rq = alloc_request(overlay);
+	rq = alloc_request(overlay, intel_overlay_off_tail);
 	if (IS_ERR(rq))
 		return PTR_ERR(rq);
 
@@ -417,17 +417,16 @@ static int intel_overlay_off(struct intel_overlay *overlay)
 	intel_ring_advance(rq, cs);
 
 	intel_overlay_flip_prepare(overlay, NULL);
+	i915_request_add(rq);
 
-	return intel_overlay_do_wait_request(overlay, rq,
-					     intel_overlay_off_tail);
+	return i915_active_wait(&overlay->last_flip);
 }
 
 /* recover from an interruption due to a signal
  * We have to be careful not to repeat work forever an make forward progess. */
 static int intel_overlay_recover_from_interrupt(struct intel_overlay *overlay)
 {
-	return i915_active_request_retire(&overlay->last_flip,
-					  &overlay->i915->drm.struct_mutex);
+	return i915_active_wait(&overlay->last_flip);
 }
 
 /* Wait for pending overlay flip and release old frame.
@@ -437,43 +436,40 @@ static int intel_overlay_recover_from_interrupt(struct intel_overlay *overlay)
 static int intel_overlay_release_old_vid(struct intel_overlay *overlay)
 {
 	struct drm_i915_private *dev_priv = overlay->i915;
+	struct i915_request *rq;
 	u32 *cs;
-	int ret;
 
 	lockdep_assert_held(&dev_priv->drm.struct_mutex);
 
-	/* Only wait if there is actually an old frame to release to
+	/*
+	 * Only wait if there is actually an old frame to release to
 	 * guarantee forward progress.
 	 */
 	if (!overlay->old_vma)
 		return 0;
 
-	if (I915_READ(GEN2_ISR) & I915_OVERLAY_PLANE_FLIP_PENDING_INTERRUPT) {
-		/* synchronous slowpath */
-		struct i915_request *rq;
+	if (!(I915_READ(GEN2_ISR) & I915_OVERLAY_PLANE_FLIP_PENDING_INTERRUPT)) {
+		intel_overlay_release_old_vid_tail(overlay);
+		return 0;
+	}
 
-		rq = alloc_request(overlay);
-		if (IS_ERR(rq))
-			return PTR_ERR(rq);
+	rq = alloc_request(overlay, intel_overlay_release_old_vid_tail);
+	if (IS_ERR(rq))
+		return PTR_ERR(rq);
 
-		cs = intel_ring_begin(rq, 2);
-		if (IS_ERR(cs)) {
-			i915_request_add(rq);
-			return PTR_ERR(cs);
-		}
+	cs = intel_ring_begin(rq, 2);
+	if (IS_ERR(cs)) {
+		i915_request_add(rq);
+		return PTR_ERR(cs);
+	}
 
-		*cs++ = MI_WAIT_FOR_EVENT | MI_WAIT_FOR_OVERLAY_FLIP;
-		*cs++ = MI_NOOP;
-		intel_ring_advance(rq, cs);
+	*cs++ = MI_WAIT_FOR_EVENT | MI_WAIT_FOR_OVERLAY_FLIP;
+	*cs++ = MI_NOOP;
+	intel_ring_advance(rq, cs);
 
-		ret = intel_overlay_do_wait_request(overlay, rq,
-						    intel_overlay_release_old_vid_tail);
-		if (ret)
-			return ret;
-	} else
-		intel_overlay_release_old_vid_tail(&overlay->last_flip, NULL);
+	i915_request_add(rq);
 
-	return 0;
+	return i915_active_wait(&overlay->last_flip);
 }
 
 void intel_overlay_reset(struct drm_i915_private *dev_priv)
@@ -1375,7 +1371,9 @@ void intel_overlay_setup(struct drm_i915_private *dev_priv)
 	overlay->contrast = 75;
 	overlay->saturation = 146;
 
-	INIT_ACTIVE_REQUEST(&overlay->last_flip);
+	i915_active_init(dev_priv,
+			 &overlay->last_flip,
+			 NULL, intel_overlay_last_flip_retire);
 
 	ret = get_registers(overlay, OVERLAY_NEEDS_PHYSICAL(dev_priv));
 	if (ret)
@@ -1409,6 +1407,7 @@ void intel_overlay_cleanup(struct drm_i915_private *dev_priv)
 	WARN_ON(overlay->active);
 
 	i915_gem_object_put(overlay->reg_bo);
+	i915_active_fini(&overlay->last_flip);
 
 	kfree(overlay);
 }

drivers/gpu/drm/i915/i915_active.h

@@ -89,25 +89,6 @@ int __must_check
 i915_active_request_set(struct i915_active_request *active,
 			struct i915_request *rq);
 
-/**
- * i915_active_request_set_retire_fn - updates the retirement callback
- * @active - the active tracker
- * @fn - the routine called when the request is retired
- * @mutex - struct_mutex used to guard retirements
- *
- * i915_active_request_set_retire_fn() updates the function pointer that
- * is called when the final request associated with the @active tracker
- * is retired.
- */
-static inline void
-i915_active_request_set_retire_fn(struct i915_active_request *active,
-				  i915_active_retire_fn fn,
-				  struct mutex *mutex)
-{
-	lockdep_assert_held(mutex);
-	active->retire = fn ?: i915_active_retire_noop;
-}
-
 /**
  * i915_active_request_raw - return the active request
  * @active - the active tracker