drm/core: add ioctl to query device/driver capabilities

We're coming to see a need to have a set of generic capability checks in
the core DRM, in addition to the driver-specific ioctls that already
exist.

This patch defines an ioctl to do as such, but does not yet define any
capabilities.

[airlied: drop the driver callback for now.]

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

4 files changed, 21 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 0d04914eb058..93a112d45c1a 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -67,6 +67,7 @@ static struct drm_ioctl_desc drm_ioctls[] = {
         DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_getmap, 0),
         DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0),
         DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0),
+        DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, 0),
         DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
 
         DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_setunique, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 117490590f56..d6de9d042b76 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -268,6 +268,17 @@ int drm_getstats(struct drm_device *dev, void *data,
 }
 
 /**
+ * Get device/driver capabilities
+ */
+int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
+{
+        struct drm_get_cap *req = data;
+
+        req->value = 0;
+        return 0;
+}
+
+/**
  * Setversion ioctl.
  *
  * \param inode device inode.
diff --git a/include/drm/drm.h b/include/drm/drm.h
index 8598cc94e169..da4efd162d58 100644
--- a/include/drm/drm.h
+++ b/include/drm/drm.h
@@ -608,6 +608,12 @@ struct drm_gem_open {
         __u64 size;
 };
 
+/** DRM_IOCTL_GET_CAP ioctl argument type */
+struct drm_get_cap {
+        __u64 capability;
+        __u64 value;
+};
+
 #include "drm_mode.h"
 
 #define DRM_IOCTL_BASE                  'd'
@@ -628,6 +634,7 @@ struct drm_gem_open {
 #define DRM_IOCTL_GEM_CLOSE             DRM_IOW (0x09, struct drm_gem_close)
 #define DRM_IOCTL_GEM_FLINK             DRM_IOWR(0x0a, struct drm_gem_flink)
 #define DRM_IOCTL_GEM_OPEN              DRM_IOWR(0x0b, struct drm_gem_open)
+#define DRM_IOCTL_GET_CAP               DRM_IOWR(0x0c, struct drm_get_cap)
 
 #define DRM_IOCTL_SET_UNIQUE            DRM_IOW( 0x10, struct drm_unique)
 #define DRM_IOCTL_AUTH_MAGIC            DRM_IOW( 0x11, struct drm_auth)
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 52a2fd2f7789..835214761d4f 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1276,6 +1276,8 @@ extern int drm_getclient(struct drm_device *dev, void *data,
                          struct drm_file *file_priv);
 extern int drm_getstats(struct drm_device *dev, void *data,
                         struct drm_file *file_priv);
+extern int drm_getcap(struct drm_device *dev, void *data,
+                      struct drm_file *file_priv);
 extern int drm_setversion(struct drm_device *dev, void *data,
                           struct drm_file *file_priv);
 extern int drm_noop(struct drm_device *dev, void *data,