tree 4f01ced816504d892db9bbeb9da05a020e1f82df
parent df115f3ee9ea703e1209392cd08f8d6783244721
author Paul Burton <paul.burton@imgtec.com> 1432481504 +0100
committer Ralf Baechle <ralf@linux-mips.org> 1434916460 +0200

MIPS: Optimise non-EVA kernel user memory accesses

Commits ac1d8590d3ae (MIPS: asm: uaccess: Use EVA instructions
wrappers), 05c6516005c4 (MIPS: asm: uaccess: Add EVA support to
copy_{in, to,from}_user) & e3a9b07a9caf (MIPS: asm: uaccess: Add EVA
support for str*_user operations) added checks to various user memory
access functions & macros in order to determine whether to perform
standard memory accesses or their EVA userspace equivalents. In kernels
built without support for EVA these checks are entirely redundant. Avoid
emitting them & allow the compiler to optimise out the EVA userspace
code in such kernels by checking config_enabled(CONFIG_EVA).

This reduces the size of a malta_defconfig kernel built using GCC 4.9.2
by approximately 33KB (from 5995072 to 5962304 bytes).

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/10165/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>