[PATCH v2 1/2] drm/nouveau: placeholders for staging ioctls

[Alexandre Courbot]

Reserve the 8 highest ioctls for "staging" features, i.e. ioctls that
may change or be dropped altogether and that thus should not be given a
definite number. This will allow us to experiment with experimental APIs
for a while before setting them in stone.

Staging ioctls are not expected to stay there for a long time, so we
limit their number. Besides, each staging ioctls needs to be explicitly
enabled through its own module option.

Signed-off-by: Alexandre Courbot <acourbot at nvidia.com>
---
 drm/nouveau/nouveau_drm.c          | 1 +
 drm/nouveau/uapi/drm/nouveau_drm.h | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/drm/nouveau/nouveau_drm.c b/drm/nouveau/nouveau_drm.c
index 63f1d39e8358..28860268cf38 100644
--- a/drm/nouveau/nouveau_drm.c
+++ b/drm/nouveau/nouveau_drm.c
@@ -896,6 +896,7 @@ nouveau_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(NOUVEAU_GEM_CPU_PREP, nouveau_gem_ioctl_cpu_prep, DRM_UNLOCKED|DRM_AUTH|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(NOUVEAU_GEM_CPU_FINI, nouveau_gem_ioctl_cpu_fini, DRM_UNLOCKED|DRM_AUTH|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(NOUVEAU_GEM_INFO, nouveau_gem_ioctl_info, DRM_UNLOCKED|DRM_AUTH|DRM_RENDER_ALLOW),
+	/* Staging ioctls */
 };
 
 long
diff --git a/drm/nouveau/uapi/drm/nouveau_drm.h b/drm/nouveau/uapi/drm/nouveau_drm.h
index 5507eead5863..4e7e21f41b5c 100644
--- a/drm/nouveau/uapi/drm/nouveau_drm.h
+++ b/drm/nouveau/uapi/drm/nouveau_drm.h
@@ -140,11 +140,14 @@ struct drm_nouveau_gem_cpu_fini {
 #define DRM_NOUVEAU_GEM_CPU_PREP       0x42
 #define DRM_NOUVEAU_GEM_CPU_FINI       0x43
 #define DRM_NOUVEAU_GEM_INFO           0x44
+/* range 0x98..DRM_COMMAND_END (8 entries) is reserved for staging, unstable ioctls */
+#define DRM_NOUVEAU_STAGING_IOCTL      0x58
 
 #define DRM_IOCTL_NOUVEAU_GEM_NEW            DRM_IOWR(DRM_COMMAND_BASE + DRM_NOUVEAU_GEM_NEW, struct drm_nouveau_gem_new)
 #define DRM_IOCTL_NOUVEAU_GEM_PUSHBUF        DRM_IOWR(DRM_COMMAND_BASE + DRM_NOUVEAU_GEM_PUSHBUF, struct drm_nouveau_gem_pushbuf)
 #define DRM_IOCTL_NOUVEAU_GEM_CPU_PREP       DRM_IOW (DRM_COMMAND_BASE + DRM_NOUVEAU_GEM_CPU_PREP, struct drm_nouveau_gem_cpu_prep)
 #define DRM_IOCTL_NOUVEAU_GEM_CPU_FINI       DRM_IOW (DRM_COMMAND_BASE + DRM_NOUVEAU_GEM_CPU_FINI, struct drm_nouveau_gem_cpu_fini)
 #define DRM_IOCTL_NOUVEAU_GEM_INFO           DRM_IOWR(DRM_COMMAND_BASE + DRM_NOUVEAU_GEM_INFO, struct drm_nouveau_gem_info)
+/* staging ioctls */
 
 #endif /* __NOUVEAU_DRM_H__ */
-- 
2.4.2