drm/fb-helper: Set flag in struct drm_fb_helper for leaking physical addresses

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 <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-21-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 95f3894..105d9c8 100644 (file)
--- 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 6581183..3dfb5d1 100644 (file)
--- 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 *