arm64: adjust el0_sync so that a function can be called

Backport of the following patch to 3.14 LSK:

commit 6ab6463aeb5fbc75fa3227befb508fc33b34dbf1
Author: Larry Bassel <larry.bassel@linaro.org>
Date:   Fri May 30 20:34:14 2014 +0100

    arm64: adjust el0_sync so that a function can be called

    To implement the context tracker properly on arm64,
    a function call needs to be made after debugging and
    interrupts are turned on, but before the lr is changed
    to point to ret_to_user(). If the function call
    is made after the lr is changed the function will not
    return to the correct place.

    For similar reasons, defer the setting of x0 so that
    it doesn't need to be saved around the function call
    (save far_el1 in x26 temporarily instead).

    Acked-by: Will Deacon <will.deacon@arm.com>
    Reviewed-by: Kevin Hilman <khilman@linaro.org>
    Tested-by: Kevin Hilman <khilman@linaro.org>
    Signed-off-by: Larry Bassel <larry.bassel@linaro.org>
    Signed-off-by: Will Deacon <will.deacon@arm.com>
    Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Signed-off-by: Larry Bassel <larry.bassel@linaro.org>

0 files changed, 0 insertions, 0 deletions