[PATCHv5 13/14] drm: Allow userspace to ask for universal plane list (v2)

[Matt Roper]

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 at intel.com>
---
 drivers/gpu/drm/drm_crtc.c  | 20 +++++++++++++++-----
 drivers/gpu/drm/drm_ioctl.c |  7 +++++++
 drivers/gpu/drm/drm_stub.c  |  5 +++++
 include/drm/drmP.h          |  6 ++++++
 include/uapi/drm/drm.h      |  8 ++++++++
 5 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 18321fb..d8b7099 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 f4dc9b7..93a4204 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 fac6f98..4c24c3a 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);
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 9e347fa..52d100c 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -409,6 +409,11 @@ struct drm_file {
 	unsigned is_master :1;
 	/* true when the client has asked us to expose stereo 3D mode flags */
 	unsigned stereo_allowed :1;
+	/*
+	 * true if client understands CRTC primary planes and cursor planes
+	 * in the plane list
+	 */
+	unsigned universal_planes:1;
 
 	struct pid *pid;
 	kuid_t uid;
@@ -1412,6 +1417,7 @@ extern void drm_put_dev(struct drm_device *dev);
 extern void drm_unplug_dev(struct drm_device *dev);
 extern unsigned int drm_debug;
 extern unsigned int drm_rnodes;
+extern unsigned int drm_universal_planes;
 
 extern unsigned int drm_vblank_offdelay;
 extern unsigned int drm_timestamp_precision;
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index ec6b259..9abbeb9 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -646,6 +646,14 @@ struct drm_get_cap {
  */
 #define DRM_CLIENT_CAP_STEREO_3D	1
 
+/**
+ * DRM_CLIENT_CAP_UNIVERSAL_PLANES
+ *
+ * If set to 1, the DRM core will expose all planes (overlay, primary, and
+ * cursor) to userspace.
+ */
+#define DRM_CLIENT_CAP_UNIVERSAL_PLANES  2
+
 /** DRM_IOCTL_SET_CLIENT_CAP ioctl argument type */
 struct drm_set_client_cap {
 	__u64 capability;
-- 
1.8.5.1