arm64: update 32-bit kuser helpers to ARMv8
authorRobin Murphy <Robin.Murphy@arm.com>
Mon, 7 Oct 2013 17:30:34 +0000 (18:30 +0100)
committerCatalin Marinas <catalin.marinas@arm.com>
Mon, 28 Oct 2013 10:40:28 +0000 (10:40 +0000)
commitd0f38f9130b7683e39611c5a661349e301ee43c8
treee6ff01a9b14fd0214fd35c704f7da4dd9484bec9
parentc019de3de61387d224ba4738e3d196aa24c88844
arm64: update 32-bit kuser helpers to ARMv8

This patch updates the barrier semantics in the kuser helper functions
to take advantage of the ARMv8 additions to AArch32, which are
guaranteed to be available in situations where these functions will be
called.

Note that this slightly changes the cmpxchg functions in that they are
no longer necessarily full barriers if they return 1. However, the
documentation only states they include their own barriers "as needed",
not that they are obligated to act as a full barrier for the caller.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
CC: Matthew Leach <matthew.leach@arm.com>
CC: Dave Martin <dave.martin@arm.com>
CC: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arch/arm64/kernel/kuser32.S