- U1copy_from_user needs PREAMBLE since it uses
  explicit ASI_BLK_AIUS references.
- Need to use EX_RETVAL() in U1memcpy.S
- U1memcpy.S can load one 64-bit word too
  many, passing the source buffer boundary
  and thus potentially causing exceptions.
Signed-off-by: David S. Miller <davem@redhat.com>