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>

2 files changed, 105 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 32756e67dd5..4fe321dc900 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -125,6 +125,15 @@ static struct drm_prop_enum_list drm_tv_subconnector_enum_list[] =
 DRM_ENUM_NAME_FN(drm_get_tv_subconnector_name,
                  drm_tv_subconnector_enum_list)
 
+static struct drm_prop_enum_list drm_dirty_info_enum_list[] = {
+        { DRM_MODE_DIRTY_OFF,      "Off"      },
+        { DRM_MODE_DIRTY_ON,       "On"       },
+        { DRM_MODE_DIRTY_ANNOTATE, "Annotate" },
+};
+
+DRM_ENUM_NAME_FN(drm_get_dirty_info_name,
+                 drm_dirty_info_enum_list)
+
 struct drm_conn_prop_enum_list {
         int type;
         char *name;
@@ -802,6 +811,36 @@ int drm_mode_create_dithering_property(struct drm_device *dev)
 EXPORT_SYMBOL(drm_mode_create_dithering_property);
 
 /**
+ * drm_mode_create_dirty_property - create dirty property
+ * @dev: DRM device
+ *
+ * Called by a driver the first time it's needed, must be attached to desired
+ * connectors.
+ */
+int drm_mode_create_dirty_info_property(struct drm_device *dev)
+{
+        struct drm_property *dirty_info;
+        int i;
+
+        if (dev->mode_config.dirty_info_property)
+                return 0;
+
+        dirty_info =
+                drm_property_create(dev, DRM_MODE_PROP_ENUM |
+                                    DRM_MODE_PROP_IMMUTABLE,
+                                    "dirty",
+                                    ARRAY_SIZE(drm_dirty_info_enum_list));
+        for (i = 0; i < ARRAY_SIZE(drm_dirty_info_enum_list); i++)
+                drm_property_add_enum(dirty_info, i,
+                                      drm_dirty_info_enum_list[i].type,
+                                      drm_dirty_info_enum_list[i].name);
+        dev->mode_config.dirty_info_property = dirty_info;
+
+        return 0;
+}
+EXPORT_SYMBOL(drm_mode_create_dirty_info_property);
+
+/**
  * drm_mode_config_init - initialize DRM mode_configuration structure
  * @dev: DRM device
  *
@@ -1753,6 +1792,71 @@ out:
         return ret;
 }
 
+int drm_mode_dirtyfb_ioctl(struct drm_device *dev,
+                           void *data, struct drm_file *file_priv)
+{
+        struct drm_clip_rect __user *clips_ptr;
+        struct drm_clip_rect *clips = NULL;
+        struct drm_mode_fb_dirty_cmd *r = data;
+        struct drm_mode_object *obj;
+        struct drm_framebuffer *fb;
+        unsigned flags;
+        int num_clips;
+        int ret = 0;
+
+        mutex_lock(&dev->mode_config.mutex);
+        obj = drm_mode_object_find(dev, r->fb_id, DRM_MODE_OBJECT_FB);
+        if (!obj) {
+                DRM_ERROR("invalid framebuffer id\n");
+                ret = -EINVAL;
+                goto out_err1;
+        }
+        fb = obj_to_fb(obj);
+
+        num_clips = r->num_clips;
+        clips_ptr = (struct drm_clip_rect *)(unsigned long)r->clips_ptr;
+
+        if (!num_clips != !clips_ptr) {
+                ret = -EINVAL;
+                goto out_err1;
+        }
+
+        flags = DRM_MODE_FB_DIRTY_FLAGS & r->flags;
+
+        /* If userspace annotates copy, clips must come in pairs */
+        if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY && (num_clips % 2)) {
+                ret = -EINVAL;
+                goto out_err1;
+        }
+
+        if (num_clips && clips_ptr) {
+                clips = kzalloc(num_clips * sizeof(*clips), GFP_KERNEL);
+                if (!clips) {
+                        ret = -ENOMEM;
+                        goto out_err1;
+                }
+
+                ret = copy_from_user(clips, clips_ptr,
+                                     num_clips * sizeof(*clips));
+                if (ret)
+                        goto out_err2;
+        }
+
+        if (fb->funcs->dirty) {
+                ret = fb->funcs->dirty(fb, flags, r->color, clips, num_clips);
+        } else {
+                ret = -ENOSYS;
+                goto out_err2;
+        }
+
+out_err2:
+        kfree(clips);
+out_err1:
+        mutex_unlock(&dev->mode_config.mutex);
+        return ret;
+}
+
+
 /**
  * drm_fb_release - remove and free the FBs on this file
  * @filp: file * from the ioctl
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index bfaf59b02bd..ff2f1042cb4 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -146,6 +146,7 @@ static struct drm_ioctl_desc drm_ioctls[] = {
         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_MASTER|DRM_CONTROL_ALLOW),
         DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_MASTER|DRM_CONTROL_ALLOW),
         DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW),
+        DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW)
 };
 
 #define DRM_CORE_IOCTL_COUNT    ARRAY_SIZE( drm_ioctls )