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Diffstat (limited to 'roms/skiboot/include/cmpxchg.h')
-rw-r--r-- | roms/skiboot/include/cmpxchg.h | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/roms/skiboot/include/cmpxchg.h b/roms/skiboot/include/cmpxchg.h new file mode 100644 index 000000000..0304e9134 --- /dev/null +++ b/roms/skiboot/include/cmpxchg.h @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later +/* Copyright 2017 IBM Corp. */ + +#ifndef __CMPXCHG_H +#define __CMPXCHG_H + +#ifndef __TEST__ +/* + * Bare cmpxchg, no barriers. + */ +static inline uint32_t __cmpxchg32(uint32_t *mem, uint32_t old, uint32_t new) +{ + uint32_t prev; + + asm volatile( + "# __cmpxchg32 \n" + "1: lwarx %0,0,%2 \n" + " cmpw %0,%3 \n" + " bne- 2f \n" + " stwcx. %4,0,%2 \n" + " bne- 1b \n" + "2: \n" + + : "=&r"(prev), "+m"(*mem) + : "r"(mem), "r"(old), "r"(new) + : "cr0"); + + return prev; +} + +static inline uint64_t __cmpxchg64(uint64_t *mem, uint64_t old, uint64_t new) +{ + uint64_t prev; + + asm volatile( + "# __cmpxchg64 \n" + "1: ldarx %0,0,%2 \n" + " cmpd %0,%3 \n" + " bne- 2f \n" + " stdcx. %4,0,%2 \n" + " bne- 1b \n" + "2: \n" + + : "=&r"(prev), "+m"(*mem) + : "r"(mem), "r"(old), "r"(new) + : "cr0"); + + return prev; +} + +static inline uint32_t cmpxchg32(uint32_t *mem, uint32_t old, uint32_t new) +{ + uint32_t prev; + + sync(); + prev = __cmpxchg32(mem, old,new); + sync(); + + return prev; +} +#endif /* __TEST_ */ + +#endif /* __CMPXCHG_H */ + + |