UPSTREAM: drm/fbdev-ttm: Support struct drm_driver.fbdev_probe

[ Upstream commit c7c1b9e ]

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 TTM-
based DRM drivers.

Change-Id: I61a1939a5260a5aaf97226dc90e97bd055a37159
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240924071734.98201-65-tzimmermann@suse.de
Stable-dep-of: 6b481ab ("drm/nouveau: select FW caching")
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit dad0617)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

Author: Thomas Zimmermann

drivers/gpu/drm/drm_fbdev_ttm.c

@@ -71,71 +71,7 @@ static const struct fb_ops drm_fbdev_ttm_fb_ops = {
 static int drm_fbdev_ttm_helper_fb_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;
-	struct fb_info *info;
-	size_t screen_size;
-	void *screen_buffer;
-	u32 format;
-	int ret;
-
-	drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
-		    sizes->surface_width, sizes->surface_height,
-		    sizes->surface_bpp);
-
-	format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp,
-					     sizes->surface_depth);
-	buffer = drm_client_framebuffer_create(client, sizes->surface_width,
-					       sizes->surface_height, format);
-	if (IS_ERR(buffer))
-		return PTR_ERR(buffer);
-
-	fb_helper->buffer = buffer;
-	fb_helper->fb = buffer->fb;
-
-	screen_size = buffer->gem->size;
-	screen_buffer = vzalloc(screen_size);
-	if (!screen_buffer) {
-		ret = -ENOMEM;
-		goto err_drm_client_framebuffer_delete;
-	}
-
-	info = drm_fb_helper_alloc_info(fb_helper);
-	if (IS_ERR(info)) {
-		ret = PTR_ERR(info);
-		goto err_vfree;
-	}
-
-	drm_fb_helper_fill_info(info, fb_helper, sizes);
-
-	info->fbops = &drm_fbdev_ttm_fb_ops;
-
-	/* screen */
-	info->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
-	info->screen_buffer = screen_buffer;
-	info->fix.smem_len = screen_size;
-
-	/* deferred I/O */
-	fb_helper->fbdefio.delay = HZ / 20;
-	fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
-
-	info->fbdefio = &fb_helper->fbdefio;
-	ret = fb_deferred_io_init(info);
-	if (ret)
-		goto err_drm_fb_helper_release_info;
-
-	return 0;
-
-err_drm_fb_helper_release_info:
-	drm_fb_helper_release_info(fb_helper);
-err_vfree:
-	vfree(screen_buffer);
-err_drm_client_framebuffer_delete:
-	fb_helper->fb = NULL;
-	fb_helper->buffer = NULL;
-	drm_client_framebuffer_delete(buffer);
-	return ret;
+	return drm_fbdev_ttm_driver_fbdev_probe(fb_helper, sizes);
 }
 
 static void drm_fbdev_ttm_damage_blit_real(struct drm_fb_helper *fb_helper,
@@ -240,6 +176,82 @@ static const struct drm_fb_helper_funcs drm_fbdev_ttm_helper_funcs = {
 	.fb_dirty = drm_fbdev_ttm_helper_fb_dirty,
 };
 
+/*
+ * struct drm_driver
+ */
+
+int drm_fbdev_ttm_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;
+	struct fb_info *info;
+	size_t screen_size;
+	void *screen_buffer;
+	u32 format;
+	int ret;
+
+	drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
+		    sizes->surface_width, sizes->surface_height,
+		    sizes->surface_bpp);
+
+	format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp,
+					     sizes->surface_depth);
+	buffer = drm_client_framebuffer_create(client, sizes->surface_width,
+					       sizes->surface_height, format);
+	if (IS_ERR(buffer))
+		return PTR_ERR(buffer);
+
+	fb_helper->funcs = &drm_fbdev_ttm_helper_funcs;
+	fb_helper->buffer = buffer;
+	fb_helper->fb = buffer->fb;
+
+	screen_size = buffer->gem->size;
+	screen_buffer = vzalloc(screen_size);
+	if (!screen_buffer) {
+		ret = -ENOMEM;
+		goto err_drm_client_framebuffer_delete;
+	}
+
+	info = drm_fb_helper_alloc_info(fb_helper);
+	if (IS_ERR(info)) {
+		ret = PTR_ERR(info);
+		goto err_vfree;
+	}
+
+	drm_fb_helper_fill_info(info, fb_helper, sizes);
+
+	info->fbops = &drm_fbdev_ttm_fb_ops;
+
+	/* screen */
+	info->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
+	info->screen_buffer = screen_buffer;
+	info->fix.smem_len = screen_size;
+
+	/* deferred I/O */
+	fb_helper->fbdefio.delay = HZ / 20;
+	fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io;
+
+	info->fbdefio = &fb_helper->fbdefio;
+	ret = fb_deferred_io_init(info);
+	if (ret)
+		goto err_drm_fb_helper_release_info;
+
+	return 0;
+
+err_drm_fb_helper_release_info:
+	drm_fb_helper_release_info(fb_helper);
+err_vfree:
+	vfree(screen_buffer);
+err_drm_client_framebuffer_delete:
+	fb_helper->fb = NULL;
+	fb_helper->buffer = NULL;
+	drm_client_framebuffer_delete(buffer);
+	return ret;
+}
+EXPORT_SYMBOL(drm_fbdev_ttm_driver_fbdev_probe);
+
 static void drm_fbdev_ttm_client_unregister(struct drm_client_dev *client)
 {
 	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);

include/drm/drm_fbdev_ttm.h

@@ -3,11 +3,24 @@
 #ifndef DRM_FBDEV_TTM_H
 #define DRM_FBDEV_TTM_H
 
+#include <linux/stddef.h>
+
 struct drm_device;
+struct drm_fb_helper;
+struct drm_fb_helper_surface_size;
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION
+int drm_fbdev_ttm_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
+				     struct drm_fb_helper_surface_size *sizes);
+
+#define DRM_FBDEV_TTM_DRIVER_OPS \
+	.fbdev_probe = drm_fbdev_ttm_driver_fbdev_probe
+
 void drm_fbdev_ttm_setup(struct drm_device *dev, unsigned int preferred_bpp);
 #else
+#define DRM_FBDEV_TTM_DRIVER_OPS \
+	.fbdev_probe = NULL
+
 static inline void drm_fbdev_ttm_setup(struct drm_device *dev, unsigned int preferred_bpp)
 { }
 #endif