950-0907-drm-vc4-crtc-Move-the-BO-Handling-out-of-Common-Page.patch

From 99c7b8eabae7a6a6e6c5f53f3a9d0996b24e10b3 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Mon, 2 May 2022 15:27:36 +0200
Subject: [PATCH] drm/vc4: crtc: Move the BO Handling out of Common
 Page-Flip Handler

The function vc4_async_page_flip() handles asynchronous page-flips in
the vc4 driver.

However, it mixes some generic code with code that should only be run on
older generations that have the GPU handled by the vc4 driver.

Let's split the generic part out of vc4_async_page_flip() and into a
common function that we be reusable by an handler made for the BCM2711.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_crtc.c | 75 ++++++++++++++++++++++------------
 1 file changed, 48 insertions(+), 27 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -912,40 +912,19 @@ static int vc4_async_set_fence_cb(struct
 	return 0;
 }
 
-/* Implements async (non-vblank-synced) page flips.
- *
- * The page flip ioctl needs to return immediately, so we grab the
- * modeset semaphore on the pipe, and queue the address update for
- * when V3D is done with the BO being flipped to.
- */
-static int vc4_async_page_flip(struct drm_crtc *crtc,
-			       struct drm_framebuffer *fb,
-			       struct drm_pending_vblank_event *event,
-			       uint32_t flags)
+static int
+vc4_async_page_flip_common(struct drm_crtc *crtc,
+			   struct drm_framebuffer *fb,
+			   struct drm_pending_vblank_event *event,
+			   uint32_t flags)
 {
 	struct drm_device *dev = crtc->dev;
 	struct drm_plane *plane = crtc->primary;
-	int ret = 0;
 	struct vc4_async_flip_state *flip_state;
-	struct drm_gem_cma_object *cma_bo = drm_fb_cma_get_gem_obj(fb, 0);
-	struct vc4_bo *bo = to_vc4_bo(&cma_bo->base);
-
-	/* Increment the BO usecnt here, so that we never end up with an
-	 * unbalanced number of vc4_bo_{dec,inc}_usecnt() calls when the
-	 * plane is later updated through the non-async path.
-	 * FIXME: we should move to generic async-page-flip when it's
-	 * available, so that we can get rid of this hand-made prepare_fb()
-	 * logic.
-	 */
-	ret = vc4_bo_inc_usecnt(bo);
-	if (ret)
-		return ret;
 
 	flip_state = kzalloc(sizeof(*flip_state), GFP_KERNEL);
-	if (!flip_state) {
-		vc4_bo_dec_usecnt(bo);
+	if (!flip_state)
 		return -ENOMEM;
-	}
 
 	drm_framebuffer_get(fb);
 	flip_state->fb = fb;
@@ -978,6 +957,48 @@ static int vc4_async_page_flip(struct dr
 	return 0;
 }
 
+/* Implements async (non-vblank-synced) page flips.
+ *
+ * The page flip ioctl needs to return immediately, so we grab the
+ * modeset semaphore on the pipe, and queue the address update for
+ * when V3D is done with the BO being flipped to.
+ */
+static int vc4_async_page_flip(struct drm_crtc *crtc,
+			       struct drm_framebuffer *fb,
+			       struct drm_pending_vblank_event *event,
+			       uint32_t flags)
+{
+	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct drm_gem_cma_object *cma_bo = drm_fb_cma_get_gem_obj(fb, 0);
+	struct vc4_bo *bo = to_vc4_bo(&cma_bo->base);
+	int ret;
+
+	if (WARN_ON_ONCE(vc4->is_vc5))
+		return -ENODEV;
+
+	/*
+	 * Increment the BO usecnt here, so that we never end up with an
+	 * unbalanced number of vc4_bo_{dec,inc}_usecnt() calls when the
+	 * plane is later updated through the non-async path.
+	 *
+	 * FIXME: we should move to generic async-page-flip when
+	 * it's available, so that we can get rid of this
+	 * hand-made prepare_fb() logic.
+	 */
+	ret = vc4_bo_inc_usecnt(bo);
+	if (ret)
+		return ret;
+
+	ret = vc4_async_page_flip_common(crtc, fb, event, flags);
+	if (ret) {
+		vc4_bo_dec_usecnt(bo);
+		return ret;
+	}
+
+	return 0;
+}
+
 int vc4_page_flip(struct drm_crtc *crtc,
 		  struct drm_framebuffer *fb,
 		  struct drm_pending_vblank_event *event,