As there are more and more complicated interactions between the different
backing stores and userspace, push the control into the backends rather
than accumulate them all inside the ioctl handlers.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20201105154934.16022-1-chris@chris-wilson.co.uk