drm: dumb scanout create/mmap for intel/radeon (v3)

This is just an idea that might or might not be a good idea,
it basically adds two ioctls to create a dumb and map a dumb buffer
suitable for scanout. The handle can be passed to the KMS ioctls to create
a framebuffer.

It looks to me like it would be useful in the following cases:
a) in development drivers - we can always provide a shadowfb fallback.
b) libkms users - we can clean up libkms a lot and avoid linking
to libdrm_*.
c) plymouth via libkms is a lot easier.

Userspace bits would be just calls + mmaps. We could probably
mark these handles somehow as not being suitable for acceleartion
so as top stop people who are dumber than dumb.

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

1 files changed, 12 insertions, 0 deletions

diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index fe29aadb129d..3cbe7a02d2aa 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -880,6 +880,17 @@ struct drm_driver {
         /* vga arb irq handler */
         void (*vgaarb_irq)(struct drm_device *dev, bool state);
 
+        /* dumb alloc support */
+        int (*dumb_create)(struct drm_file *file_priv,
+                           struct drm_device *dev,
+                           struct drm_mode_create_dumb *args);
+        int (*dumb_map_offset)(struct drm_file *file_priv,
+                               struct drm_device *dev, uint32_t handle,
+                               uint64_t *offset);
+        int (*dumb_destroy)(struct drm_file *file_priv,
+                            struct drm_device *dev,
+                            uint32_t handle);
+
         /* Driver private ops for this object */
         struct vm_operations_struct *gem_vm_ops;
 
@@ -1544,6 +1555,7 @@ drm_gem_object_unreference_unlocked(struct drm_gem_object *obj)
 int drm_gem_handle_create(struct drm_file *file_priv,
                           struct drm_gem_object *obj,
                           u32 *handlep);
+int drm_gem_handle_delete(struct drm_file *filp, u32 handle);
 
 static inline void
 drm_gem_object_handle_reference(struct drm_gem_object *obj)