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

Thomas Zimmermann
2022-11-03T15:17:56Z

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>
---
drivers/gpu/drm/drm_fb_helper.c | 10 +++++++---
include/drm/drm_fb_helper.h | 2 ++
2 files changed, 9 insertions(+), 3 deletions(-)

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 *
--
2.38.0