Support alocation of GRU contexts that contain zero DSR or CBR resources. Some instructions do not require DSR resources. Contexts without CBR resources are useful for diagnostics. Signed-off-by: Jack Steiner <steiner@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>