MIPS: include: Mark __cmpxchg as __always_inline

Commit ac7c3e4ff4 ("compiler: enable CONFIG_OPTIMIZE_INLINING
forcibly") allows compiler to uninline functions marked as 'inline'.
In cace of cmpxchg this would cause to reference function
__cmpxchg_called_with_bad_pointer, which is a error case
for catching bugs and will not happen for correct code, if
__cmpxchg is inlined.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
[paul.burton@mips.com: s/__cmpxchd/__cmpxchg in subject]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

arch/mips/include/asm/cmpxchg.h

@@ -153,7 +153,8 @@ static inline unsigned long __xchg(volatile void *ptr, unsigned long x,
 extern unsigned long __cmpxchg_small(volatile void *ptr, unsigned long old,
 				     unsigned long new, unsigned int size);
 
-static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
+static __always_inline
+unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
 			unsigned long new, unsigned int size)
 {
 	switch (size) {