[v3,20/23] drm/fb-helper: Set flag in struct drm_fb_helper for leaking physical addresses

Commit Message

Thomas Zimmermann Nov. 3, 2022, 3:14 p.m. UTC

Uncouple the parameter drm_leak_fbdev_smem from the implementation by
setting a flag in struct drm_fb_helper. This will help to move the
generic fbdev emulation into its own source file, while keeping the
parameter in drm_fb_helper.c. No functional changes.

Signed-off-by: Thomas Zimmermann <[e-mail]>
---
 drivers/gpu/drm/drm_fb_helper.c | 10 +++++++---
 include/drm/drm_fb_helper.h     |  2 ++
 2 files changed, 9 insertions(+), 3 deletions(-)

Comments

Javier Martinez Canillas Nov. 4, 2022, 10:37 a.m. UTC | #1

On 11/3/22 16:14, Thomas Zimmermann wrote:
> Uncouple the parameter drm_leak_fbdev_smem from the implementation by
> setting a flag in struct drm_fb_helper. This will help to move the
> generic fbdev emulation into its own source file, while keeping the
> parameter in drm_fb_helper.c. No functional changes.
> 
> Signed-off-by: Thomas Zimmermann <[e-mail]>
> ---

Reviewed-by: Javier Martinez Canillas <[e-mail]>

Patch

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 95f389433c4a6..105d9c8fe3250 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -74,7 +74,7 @@  MODULE_PARM_DESC(drm_fbdev_overalloc,
  * considered as a broken and legacy behaviour from a modern fbdev device.
  */
 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
-static bool drm_leak_fbdev_smem = false;
+static bool drm_leak_fbdev_smem;
 module_param_unsafe(drm_leak_fbdev_smem, bool, 0600);
 MODULE_PARM_DESC(drm_leak_fbdev_smem,
 		 "Allow unsafe leaking fbdev physical smem address [default=false]");
@@ -1968,6 +1968,10 @@  static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
 		sizes.surface_height = config->max_height;
 	}
 
+#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
+	fb_helper->hint_leak_smem_start = drm_leak_fbdev_smem;
+#endif
+
 	/* push down into drivers */
 	ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
 	if (ret < 0)
@@ -2165,7 +2169,7 @@  __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper,
 	info->var.pixclock = 0;
 	/* Shamelessly allow physical address leaking to userspace */
 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
-	if (!drm_leak_fbdev_smem)
+	if (!fb_helper->hint_leak_smem_start)
 #endif
 		/* don't leak any physical addresses to userspace */
 		info->flags |= FBINFO_HIDE_SMEM_START;
@@ -2564,7 +2568,7 @@  static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
 		 * case.
 		 */
 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
-		if (drm_leak_fbdev_smem && fbi->fix.smem_start == 0 &&
+		if (fb_helper->hint_leak_smem_start && fbi->fix.smem_start == 0 &&
 		    !drm_WARN_ON_ONCE(dev, map.is_iomem))
 			fbi->fix.smem_start =
 				page_to_phys(virt_to_page(fbi->screen_buffer));
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 6581183618b89..3dfb5d1093871 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -199,6 +199,8 @@  struct drm_fb_helper {
 	 * See also: @deferred_setup
 	 */
 	int preferred_bpp;
+
+	bool hint_leak_smem_start;
 };
 
 static inline struct drm_fb_helper *