[PATCH v3 4/7] drm/mgag200: Move vmap out of commit tail

From: Thomas Zimmermann <tzimmermann@suse.de>
To: daniel@ffwll.ch, airlied@linux.ie,
	maarten.lankhorst@linux.intel.com, mripard@kernel.org,
	kraxel@redhat.com, hdegoede@redhat.com, sean@poorly.run,
	sam@ravnborg.org, noralf@tronnes.org
Cc: Thomas Zimmermann <tzimmermann@suse.de>,
	dri-devel@lists.freedesktop.org,
	virtualization@lists.linux-foundation.org
Subject: [PATCH v3 4/7] drm/mgag200: Move vmap out of commit tail
Date: Mon,  8 Feb 2021 12:55:35 +0100	[thread overview]
Message-ID: <20210208115538.6430-5-tzimmermann@suse.de> (raw)
In-Reply-To: <20210208115538.6430-1-tzimmermann@suse.de>

Vmap operations may acquire the dmabuf reservation lock, which is not
allowed within atomic commit-tail functions. Therefore move vmap and
vunmap from the damage handler into prepare_fb and cleanup_fb callbacks.

The mapping is provided as GEM shadow-buffered plane. The functions in
the commit tail use the pre-established mapping for damage handling.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
---
 drivers/gpu/drm/mgag200/mgag200_mode.c | 23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index c3dfde8cad25..cece3e57fb27 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -17,6 +17,7 @@
 #include <drm/drm_damage_helper.h>
 #include <drm/drm_format_helper.h>
 #include <drm/drm_fourcc.h>
+#include <drm/drm_gem_atomic_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_plane_helper.h>
 #include <drm/drm_print.h>
@@ -1549,22 +1550,12 @@ mgag200_simple_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
 
 static void
 mgag200_handle_damage(struct mga_device *mdev, struct drm_framebuffer *fb,
-		      struct drm_rect *clip)
+		      struct drm_rect *clip, const struct dma_buf_map *map)
 {
-	struct drm_device *dev = &mdev->base;
-	struct dma_buf_map map;
-	void *vmap;
-	int ret;
-
-	ret = drm_gem_shmem_vmap(fb->obj[0], &map);
-	if (drm_WARN_ON(dev, ret))
-		return; /* BUG: SHMEM BO should always be vmapped */
-	vmap = map.vaddr; /* TODO: Use mapping abstraction properly */
+	void *vmap = map->vaddr; /* TODO: Use mapping abstraction properly */
 
 	drm_fb_memcpy_dstclip(mdev->vram, vmap, fb, clip);
 
-	drm_gem_shmem_vunmap(fb->obj[0], &map);
-
 	/* Always scanout image at VRAM offset 0 */
 	mgag200_set_startadd(mdev, (u32)0);
 	mgag200_set_offset(mdev, fb);
@@ -1580,6 +1571,7 @@ mgag200_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
 	struct mga_device *mdev = to_mga_device(dev);
 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
 	struct drm_framebuffer *fb = plane_state->fb;
+	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
 	struct drm_rect fullscreen = {
 		.x1 = 0,
 		.x2 = fb->width,
@@ -1608,7 +1600,7 @@ mgag200_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
 	mga_crtc_load_lut(crtc);
 	mgag200_enable_display(mdev);
 
-	mgag200_handle_damage(mdev, fb, &fullscreen);
+	mgag200_handle_damage(mdev, fb, &fullscreen, &shadow_plane_state->map[0]);
 }
 
 static void
@@ -1649,6 +1641,7 @@ mgag200_simple_display_pipe_update(struct drm_simple_display_pipe *pipe,
 	struct drm_device *dev = plane->dev;
 	struct mga_device *mdev = to_mga_device(dev);
 	struct drm_plane_state *state = plane->state;
+	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
 	struct drm_framebuffer *fb = state->fb;
 	struct drm_rect damage;
 
@@ -1656,7 +1649,7 @@ mgag200_simple_display_pipe_update(struct drm_simple_display_pipe *pipe,
 		return;
 
 	if (drm_atomic_helper_damage_merged(old_state, state, &damage))
-		mgag200_handle_damage(mdev, fb, &damage);
+		mgag200_handle_damage(mdev, fb, &damage, &shadow_plane_state->map[0]);
 }
 
 static const struct drm_simple_display_pipe_funcs
@@ -1666,7 +1659,7 @@ mgag200_simple_display_pipe_funcs = {
 	.disable    = mgag200_simple_display_pipe_disable,
 	.check	    = mgag200_simple_display_pipe_check,
 	.update	    = mgag200_simple_display_pipe_update,
-	.prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
+	DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
 };
 
 static const uint32_t mgag200_simple_display_pipe_formats[] = {
-- 
2.30.0

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