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@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
---
arch/mips/include/asm/cmpxchg.h | 59 ++++++++++++++++++++++-------------------
1 file changed, 32 insertions(+), 27 deletions(-)
diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h
index e9c1e97bc29d..516cb66f066b 100644
--- a/arch/mips/include/asm/cmpxchg.h
+++ b/arch/mips/include/asm/cmpxchg.h
@@ -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; \
- \
- 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; \
- } \
+ __typeof__(*(ptr)) __res; \
\
- 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) \
({ \
--
2.13.1
