diff options
| -rw-r--r-- | arch/sparc/include/asm/cmpxchg_64.h | 49 |
1 files changed, 39 insertions, 10 deletions
diff --git a/arch/sparc/include/asm/cmpxchg_64.h b/arch/sparc/include/asm/cmpxchg_64.h index 000f7d7a2d4a..4028f4f1e561 100644 --- a/arch/sparc/include/asm/cmpxchg_64.h +++ b/arch/sparc/include/asm/cmpxchg_64.h @@ -6,6 +6,17 @@ #ifndef __ARCH_SPARC64_CMPXCHG__ #define __ARCH_SPARC64_CMPXCHG__ +static inline unsigned long +__cmpxchg_u32(volatile int *m, int old, int new) +{ + __asm__ __volatile__("cas [%2], %3, %0" + : "=&r" (new) + : "0" (new), "r" (m), "r" (old) + : "memory"); + + return new; +} + static inline unsigned long xchg32(__volatile__ unsigned int *m, unsigned int val) { unsigned long tmp1, tmp2; @@ -44,10 +55,38 @@ static inline unsigned long xchg64(__volatile__ unsigned long *m, unsigned long void __xchg_called_with_bad_pointer(void); +/* + * Use 4 byte cas instruction to achieve 2 byte xchg. Main logic + * here is to get the bit shift of the byte we are interested in. + * The XOR is handy for reversing the bits for big-endian byte order. + */ +static inline unsigned long +xchg16(__volatile__ unsigned short *m, unsigned short val) +{ + unsigned long maddr = (unsigned long)m; + int bit_shift = (((unsigned long)m & 2) ^ 2) << 3; + unsigned int mask = 0xffff << bit_shift; + unsigned int *ptr = (unsigned int *) (maddr & ~2); + unsigned int old32, new32, load32; + + /* Read the old value */ + load32 = *ptr; + + do { + old32 = load32; + new32 = (load32 & (~mask)) | val << bit_shift; + load32 = __cmpxchg_u32(ptr, old32, new32); + } while (load32 != old32); + + return (load32 & mask) >> bit_shift; +} + static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr, int size) { switch (size) { + case 2: + return xchg16(ptr, x); case 4: return xchg32(ptr, x); case 8: @@ -65,16 +104,6 @@ static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr, #include <asm-generic/cmpxchg-local.h> -static inline unsigned long -__cmpxchg_u32(volatile int *m, int old, int new) -{ - __asm__ __volatile__("cas [%2], %3, %0" - : "=&r" (new) - : "0" (new), "r" (m), "r" (old) - : "memory"); - - return new; -} static inline unsigned long __cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new) |