diff options
| author | Paul Burton <paul.burton@imgtec.com> | 2017-06-10 02:26:38 +0200 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2017-06-29 02:42:25 +0200 |
| commit | 8263db4d7768448cb06adbbdd14c613a1ea09830 (patch) | |
| tree | 7191e01be77bf903f87fb730e519152dcd8a5c58 /arch | |
| parent | MIPS: cmpxchg: Drop __xchg_u{32,64} functions (diff) | |
| download | linux-8263db4d7768448cb06adbbdd14c613a1ea09830.tar.xz linux-8263db4d7768448cb06adbbdd14c613a1ea09830.zip | |
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>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/mips/include/asm/cmpxchg.h | 59 |
1 files 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) \ ({ \ |