drm/mgag200: Replace VRAM helpers with SHMEM helpers

The VRAM helpers managed the framebuffer memory for mgag200. This came
with several problems, as some MGA device require the scanout address
to be located at VRAM offset 0. It's incompatible with the page-flip
semantics of DRM's atomic modesettting. With atomic modesetting, old and
new framebuffers have to be located in VRAM at the same time. So at least
one of them has to reside at a non-0 offset.

This patch replaces VRAM helpers with SHMEM helpers. GEM SHMEM buffers
reside in system memory, and are shadow-copied into VRAM during page
flips. The shadow copy always starts at VRAM offset 0.

v2:
	* revert dev->pdev changes

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: John Donnelly <John.p.donnelly@oracle.com>
Acked-by: Emil Velikov <emil.velikov@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200515083233.32036-16-tzimmermann@suse.de

1 files changed, 35 insertions, 23 deletions

diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index b50c1beb7b7b..0155d4eb5fa6 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -14,6 +14,8 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_atomic_state_helper.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_format_helper.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_plane_helper.h>
@@ -1574,6 +1576,26 @@ 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_device *dev = mdev->dev;
+	void *vmap;
+
+	vmap = drm_gem_shmem_vmap(fb->obj[0]);
+	if (drm_WARN_ON(dev, !vmap))
+		return; /* BUG: SHMEM BO should always be vmapped */
+
+	drm_fb_memcpy_dstclip(mdev->vram, vmap, fb, clip);
+
+	drm_gem_shmem_vunmap(fb->obj[0], vmap);
+
+	/* Always scanout image at VRAM offset 0 */
+	mgag200_set_startadd(mdev, (u32)0);
+	mgag200_set_offset(mdev, fb);
+}
+
+static void
 mgag200_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
 				   struct drm_crtc_state *crtc_state,
 				   struct drm_plane_state *plane_state)
@@ -1583,14 +1605,12 @@ 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_gem_vram_object *gbo;
-	s64 gpu_addr;
-
-	gbo = drm_gem_vram_of_gem(fb->obj[0]);
-
-	gpu_addr = drm_gem_vram_offset(gbo);
-	if (drm_WARN_ON_ONCE(dev, gpu_addr < 0))
-		return; /* BUG: BO should have been pinned to VRAM. */
+	struct drm_rect fullscreen = {
+		.x1 = 0,
+		.x2 = fb->width,
+		.y1 = 0,
+		.y2 = fb->height,
+	};
 
 	mga_crtc_prepare(crtc);
 
@@ -1606,6 +1626,8 @@ mgag200_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
 		mgag200_g200ev_set_hiprilvl(mdev);
 
 	mga_crtc_commit(crtc);
+
+	mgag200_handle_damage(mdev, fb, &fullscreen);
 }
 
 static void
@@ -1646,20 +1668,13 @@ mgag200_simple_display_pipe_update(struct drm_simple_display_pipe *pipe,
 	struct mga_device *mdev = to_mga_device(dev);
 	struct drm_plane_state *state = plane->state;
 	struct drm_framebuffer *fb = state->fb;
-	struct drm_gem_vram_object *gbo;
-	s64 gpu_addr;
+	struct drm_rect damage;
 
 	if (!fb)
 		return;
 
-	gbo = drm_gem_vram_of_gem(fb->obj[0]);
-
-	gpu_addr = drm_gem_vram_offset(gbo);
-	if (drm_WARN_ON_ONCE(dev, gpu_addr < 0))
-		return; /* BUG: BO should have been pinned to VRAM. */
-
-	mgag200_set_startadd(mdev, (unsigned long)gpu_addr);
-	mgag200_set_offset(mdev, fb);
+	if (drm_atomic_helper_damage_merged(old_state, state, &damage))
+		mgag200_handle_damage(mdev, fb, &damage);
 }
 
 static const struct drm_simple_display_pipe_funcs
@@ -1669,8 +1684,7 @@ 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_vram_simple_display_pipe_prepare_fb,
-	.cleanup_fb = drm_gem_vram_simple_display_pipe_cleanup_fb,
+	.prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
 };
 
 static const uint32_t mgag200_simple_display_pipe_formats[] = {
@@ -1689,8 +1703,7 @@ static const uint64_t mgag200_simple_display_pipe_fmtmods[] = {
  */
 
 static const struct drm_mode_config_funcs mgag200_mode_config_funcs = {
-	.fb_create     = drm_gem_fb_create,
-	.mode_valid    = drm_vram_helper_mode_valid,
+	.fb_create     = drm_gem_fb_create_with_dirty,
 	.atomic_check  = drm_atomic_helper_check,
 	.atomic_commit = drm_atomic_helper_commit,
 };
@@ -1729,7 +1742,6 @@ int mgag200_modeset_init(struct mga_device *mdev)
 	dev->mode_config.max_height = MGAG200_MAX_FB_HEIGHT;
 
 	dev->mode_config.preferred_depth = mgag200_preferred_depth(mdev);
-	dev->mode_config.prefer_shadow = 1;
 
 	dev->mode_config.fb_base = mdev->mc.vram_base;