arm64: fix unreachable code issue with cmpxchg

On arm64 build with clang, sometimes the __cmpxchg_mb is not inlined
when CONFIG_OPTIMIZE_INLINING is set.
Clang then fails a compile-time assertion, because it cannot tell at
compile time what the size of the argument is:

mm/memcontrol.o: In function `__cmpxchg_mb':
memcontrol.c:(.text+0x1a4c): undefined reference to `__compiletime_assert_175'
memcontrol.c:(.text+0x1a4c): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `__compiletime_assert_175'

Mark all of the cmpxchg() style functions as __always_inline to
ensure that the compiler can see the result.

Acked-by: Nick Desaulniers <[email protected]>
Reported-by: Nathan Chancellor <[email protected]>
Link: https://github.com/ClangBuiltLinux/linux/issues/648
Reviewed-by: Nathan Chancellor <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
Reviewed-by: Andrew Murray <[email protected]>
Tested-by: Andrew Murray <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Will Deacon <[email protected]>

0 files changed, 0 insertions, 0 deletions