drm: Add dirty ioctl and property

This commit adds a ioctl and property to allow userspace
to notify the kernel that a framebuffer has changed. Instead
of snooping the command stream this allows finer grained
tracking of which areas have changed.

The primary user for this functionality is virtual hardware
like the vmware svga device, but also Xen hardware likes to
be notify. There is also real hardware like DisplayLink and
DisplayPort that might take advantage of this ioctl.

Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/include/drm/drm_mode.h b/include/drm/drm_mode.h
index 09ca6adf4dd5..43009bc2e757 100644
--- a/include/drm/drm_mode.h
+++ b/include/drm/drm_mode.h
@@ -75,6 +75,11 @@
 #define DRM_MODE_DITHERING_OFF  0
 #define DRM_MODE_DITHERING_ON   1
 
+/* Dirty info options */
+#define DRM_MODE_DIRTY_OFF      0
+#define DRM_MODE_DIRTY_ON       1
+#define DRM_MODE_DIRTY_ANNOTATE 2
+
 struct drm_mode_modeinfo {
         __u32 clock;
         __u16 hdisplay, hsync_start, hsync_end, htotal, hskew;
@@ -222,6 +227,45 @@ struct drm_mode_fb_cmd {
         __u32 handle;
 };
 
+#define DRM_MODE_FB_DIRTY_ANNOTATE_COPY 0x01
+#define DRM_MODE_FB_DIRTY_ANNOTATE_FILL 0x02
+#define DRM_MODE_FB_DIRTY_FLAGS         0x03
+
+/*
+ * Mark a region of a framebuffer as dirty.
+ *
+ * Some hardware does not automatically update display contents
+ * as a hardware or software draw to a framebuffer. This ioctl
+ * allows userspace to tell the kernel and the hardware what
+ * regions of the framebuffer have changed.
+ *
+ * The kernel or hardware is free to update more then just the
+ * region specified by the clip rects. The kernel or hardware
+ * may also delay and/or coalesce several calls to dirty into a
+ * single update.
+ *
+ * Userspace may annotate the updates, the annotates are a
+ * promise made by the caller that the change is either a copy
+ * of pixels or a fill of a single color in the region specified.
+ *
+ * If the DRM_MODE_FB_DIRTY_ANNOTATE_COPY flag is given then
+ * the number of updated regions are half of num_clips given,
+ * where the clip rects are paired in src and dst. The width and
+ * height of each one of the pairs must match.
+ *
+ * If the DRM_MODE_FB_DIRTY_ANNOTATE_FILL flag is given the caller
+ * promises that the region specified of the clip rects is filled
+ * completely with a single color as given in the color argument.
+ */
+
+struct drm_mode_fb_dirty_cmd {
+        __u32 fb_id;
+        __u32 flags;
+        __u32 color;
+        __u32 num_clips;
+        __u64 clips_ptr;
+};
+
 struct drm_mode_mode_cmd {
         __u32 connector_id;
         struct drm_mode_modeinfo mode;