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MIPS: cmpxchg: Implement __cmpxchg() as a function 

Replace the macro definition of __cmpxchg() with an inline function,
which is easier to read & modify. The cmpxchg() & cmpxchg_local() macros
are adjusted to call the new __cmpxchg() function.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16353/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
hifive-unleashed-5.1
Paul Burton 2017-06-09 17:26:38 -07:00 committed by Ralf Baechle
parent 62c6081dca
commit 8263db4d77
1 changed files with 32 additions and 27 deletions
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59
arch/mips/include/asm/cmpxchg.h
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@ -34,7 +34,7 @@
*
* - Get an error at link-time due to the call to the missing function.
*/
extern void __cmpxchg_called_with_bad_pointer(void)
extern unsigned long __cmpxchg_called_with_bad_pointer(void)
__compiletime_error("Bad argument size for cmpxchg");
extern unsigned long __xchg_called_with_bad_pointer(void)
__compiletime_error("Bad argument size for xchg");
@ -137,38 +137,43 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
__ret; \
})
#define __cmpxchg(ptr, old, new, pre_barrier, post_barrier) \
static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
unsigned long new, unsigned int size)
{
switch (size) {
case 4:
return __cmpxchg_asm("ll", "sc", (volatile u32 *)ptr, old, new);
case 8:
/* lld/scd are only available for MIPS64 */
if (!IS_ENABLED(CONFIG_64BIT))
return __cmpxchg_called_with_bad_pointer();
return __cmpxchg_asm("lld", "scd", (volatile u64 *)ptr, old, new);
default:
return __cmpxchg_called_with_bad_pointer();
}
}
#define cmpxchg_local(ptr, old, new) \
((__typeof__(*(ptr))) \
__cmpxchg((ptr), \
(unsigned long)(__typeof__(*(ptr)))(old), \
(unsigned long)(__typeof__(*(ptr)))(new), \
sizeof(*(ptr))))
#define cmpxchg(ptr, old, new) \
({ \
__typeof__(ptr) __ptr = (ptr); \
__typeof__(*(ptr)) __old = (old); \
__typeof__(*(ptr)) __new = (new); \
__typeof__(*(ptr)) __res = 0; \
__typeof__(*(ptr)) __res; \
\
pre_barrier; \
\
switch (sizeof(*(__ptr))) { \
case 4: \
__res = __cmpxchg_asm("ll", "sc", __ptr, __old, __new); \
break; \
case 8: \
if (sizeof(long) == 8) { \
__res = __cmpxchg_asm("lld", "scd", __ptr, \
__old, __new); \
break; \
} \
default: \
__cmpxchg_called_with_bad_pointer(); \
break; \
} \
\
post_barrier; \
smp_mb__before_llsc(); \
__res = cmpxchg_local((ptr), (old), (new)); \
smp_llsc_mb(); \
\
__res; \
})
#define cmpxchg(ptr, old, new) __cmpxchg(ptr, old, new, smp_mb__before_llsc(), smp_llsc_mb())
#define cmpxchg_local(ptr, old, new) __cmpxchg(ptr, old, new, , )
#ifdef CONFIG_64BIT
#define cmpxchg64_local(ptr, o, n) \
({ \