drm/fbdev-shmem: Support struct drm_driver.fbdev_probe

Rework fbdev probing to support fbdev_probe in struct drm_driver
and reimplement the old fb_probe callback on top of it. Provide an
initializer macro for struct drm_driver that sets the callback
according to the kernel configuration.

This change allows the common fbdev client to run on top of SHMEM-
based DRM drivers.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240924071734.98201-50-tzimmermann@suse.de

2 files changed, 47 insertions, 24 deletions

diff --git a/drivers/gpu/drm/drm_fbdev_shmem.c b/drivers/gpu/drm/drm_fbdev_shmem.c
index 0c785007f11b..3bca333917d1 100644
--- a/drivers/gpu/drm/drm_fbdev_shmem.c
+++ b/drivers/gpu/drm/drm_fbdev_shmem.c
@@ -108,6 +108,40 @@ static struct page *drm_fbdev_shmem_get_page(struct fb_info *info, unsigned long
 static int drm_fbdev_shmem_helper_fb_probe(struct drm_fb_helper *fb_helper,
 					   struct drm_fb_helper_surface_size *sizes)
 {
+	return drm_fbdev_shmem_driver_fbdev_probe(fb_helper, sizes);
+}
+
+static int drm_fbdev_shmem_helper_fb_dirty(struct drm_fb_helper *helper,
+					   struct drm_clip_rect *clip)
+{
+	struct drm_device *dev = helper->dev;
+	int ret;
+
+	/* Call damage handlers only if necessary */
+	if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
+		return 0;
+
+	if (helper->fb->funcs->dirty) {
+		ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
+		if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct drm_fb_helper_funcs drm_fbdev_shmem_helper_funcs = {
+	.fb_probe = drm_fbdev_shmem_helper_fb_probe,
+	.fb_dirty = drm_fbdev_shmem_helper_fb_dirty,
+};
+
+/*
+ * struct drm_driver
+ */
+
+int drm_fbdev_shmem_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
+				       struct drm_fb_helper_surface_size *sizes)
+{
 	struct drm_client_dev *client = &fb_helper->client;
 	struct drm_device *dev = fb_helper->dev;
 	struct drm_client_buffer *buffer;
@@ -139,6 +173,7 @@ static int drm_fbdev_shmem_helper_fb_probe(struct drm_fb_helper *fb_helper,
 		goto err_drm_client_buffer_delete;
 	}
 
+	fb_helper->funcs = &drm_fbdev_shmem_helper_funcs;
 	fb_helper->buffer = buffer;
 	fb_helper->fb = fb;
 
@@ -182,30 +217,7 @@ err_drm_client_buffer_delete:
 	drm_client_framebuffer_delete(buffer);
 	return ret;
 }
-
-static int drm_fbdev_shmem_helper_fb_dirty(struct drm_fb_helper *helper,
-					   struct drm_clip_rect *clip)
-{
-	struct drm_device *dev = helper->dev;
-	int ret;
-
-	/* Call damage handlers only if necessary */
-	if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
-		return 0;
-
-	if (helper->fb->funcs->dirty) {
-		ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
-		if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))
-			return ret;
-	}
-
-	return 0;
-}
-
-static const struct drm_fb_helper_funcs drm_fbdev_shmem_helper_funcs = {
-	.fb_probe = drm_fbdev_shmem_helper_fb_probe,
-	.fb_dirty = drm_fbdev_shmem_helper_fb_dirty,
-};
+EXPORT_SYMBOL(drm_fbdev_shmem_driver_fbdev_probe);
 
 /*
  * struct drm_client_funcs
diff --git a/include/drm/drm_fbdev_shmem.h b/include/drm/drm_fbdev_shmem.h
index fb43cadd1950..3a5d1efa9d55 100644
--- a/include/drm/drm_fbdev_shmem.h
+++ b/include/drm/drm_fbdev_shmem.h
@@ -4,12 +4,23 @@
 #define DRM_FBDEV_SHMEM_H
 
 struct drm_device;
+struct drm_fb_helper;
+struct drm_fb_helper_surface_size;
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION
+int drm_fbdev_shmem_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
+				       struct drm_fb_helper_surface_size *sizes);
+
+#define DRM_FBDEV_SHMEM_DRIVER_OPS \
+	.fbdev_probe = drm_fbdev_shmem_driver_fbdev_probe
+
 void drm_fbdev_shmem_setup(struct drm_device *dev, unsigned int preferred_bpp);
 #else
 static inline void drm_fbdev_shmem_setup(struct drm_device *dev, unsigned int preferred_bpp)
 { }
+
+#define DRM_FBDEV_SHMEM_DRIVER_OPS \
+	.fbdev_probe = NULL
 #endif
 
 #endif