[PATCH v2 07/20] arm64: introduce CONFIG_ARM64_LSE_ATOMICS as fallback to ll/sc atomics

[Catalin Marinas]

On Fri, Jul 24, 2015 at 11:41:58AM +0100, Will Deacon wrote:
> In order to patch in the new atomic instructions at runtime, we need to
> generate wrappers around the out-of-line exclusive load/store atomics.
> 
> This patch adds a new Kconfig option, CONFIG_ARM64_LSE_ATOMICS. which
> causes our atomic functions to branch to the out-of-line ll/sc
> implementations. To avoid the register spill overhead of the PCS, the
> out-of-line functions are compiled with specific compiler flags to
> force out-of-line save/restore of any registers that are usually
> caller-saved.
> 
> Signed-off-by: Will Deacon <will.deacon at arm.com>

Slightly easier to read now ;).

Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>