drm: Allow userspace to ask for universal plane list (v2)

Userspace clients which wish to receive all DRM planes (primary and
cursor planes in addition to the traditional overlay planes) may set the
DRM_CLIENT_CAP_UNIVERSAL_PLANES capability.

v2: Hide behind drm.universal_planes module option [suggested by
    Daniel Vetter]

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>

3 files changed, 27 insertions, 5 deletions

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 18321fb16e8c..d8b7099abece 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1959,6 +1959,7 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data,
 	struct drm_plane *plane;
 	uint32_t __user *plane_ptr;
 	int copied = 0, ret = 0;
+	unsigned num_planes;
 
 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
 		return -EINVAL;
@@ -1966,17 +1967,26 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data,
 	drm_modeset_lock_all(dev);
 	config = &dev->mode_config;
 
+	if (file_priv->universal_planes)
+		num_planes = config->num_total_plane;
+	else
+		num_planes = config->num_overlay_plane;
+
 	/*
 	 * This ioctl is called twice, once to determine how much space is
 	 * needed, and the 2nd time to fill it.
 	 */
-	if (config->num_overlay_plane &&
-	    (plane_resp->count_planes >= config->num_overlay_plane)) {
+	if (num_planes &&
+	    (plane_resp->count_planes >= num_planes)) {
 		plane_ptr = (uint32_t __user *)(unsigned long)plane_resp->plane_id_ptr;
 
 		list_for_each_entry(plane, &config->plane_list, head) {
-			/* Only advertise overlays to userspace for now. */
-			if (plane->type != DRM_PLANE_TYPE_OVERLAY)
+			/*
+			 * Unless userspace set the 'universal planes'
+			 * capability bit, only advertise overlays.
+			 */
+			if (plane->type != DRM_PLANE_TYPE_OVERLAY &&
+			    !file_priv->universal_planes)
 				continue;
 
 			if (put_user(plane->base.id, plane_ptr + copied)) {
@@ -1986,7 +1996,7 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data,
 			copied++;
 		}
 	}
-	plane_resp->count_planes = config->num_overlay_plane;
+	plane_resp->count_planes = num_planes;
 
 out:
 	drm_modeset_unlock_all(dev);
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index f4dc9b7a3831..93a42040bedb 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -328,6 +328,13 @@ drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
 			return -EINVAL;
 		file_priv->stereo_allowed = req->value;
 		break;
+	case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
+		if (!drm_universal_planes)
+			return -EINVAL;
+		if (req->value > 1)
+			return -EINVAL;
+		file_priv->universal_planes = req->value;
+		break;
 	default:
 		return -EINVAL;
 	}
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index fac6f9834257..4c24c3ac1efa 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -45,6 +45,10 @@ EXPORT_SYMBOL(drm_debug);
 unsigned int drm_rnodes = 0;	/* 1 to enable experimental render nodes API */
 EXPORT_SYMBOL(drm_rnodes);
 
+/* 1 to allow user space to request universal planes (experimental) */
+unsigned int drm_universal_planes = 0;
+EXPORT_SYMBOL(drm_universal_planes);
+
 unsigned int drm_vblank_offdelay = 5000;    /* Default to 5000 msecs. */
 EXPORT_SYMBOL(drm_vblank_offdelay);
 
@@ -68,6 +72,7 @@ MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
 
 module_param_named(debug, drm_debug, int, 0600);
 module_param_named(rnodes, drm_rnodes, int, 0600);
+module_param_named(universal_planes, drm_universal_planes, int, 0600);
 module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
 module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
 module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);