git: e0363a08dc45 - stable/12 - atomic: Add atomic_cmpset_masked to powerpc and use it
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Date: Thu, 07 Oct 2021 03:28:13 UTC
The branch stable/12 has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=e0363a08dc453be7b67f38d8a9663ff41dde94ee commit e0363a08dc453be7b67f38d8a9663ff41dde94ee Author: Justin Hibbits <jhibbits@FreeBSD.org> AuthorDate: 2019-11-15 04:33:07 +0000 Commit: Kyle Evans <kevans@FreeBSD.org> CommitDate: 2021-10-07 03:27:27 +0000 atomic: Add atomic_cmpset_masked to powerpc and use it Summary: This is a more optimal way of doing atomic_compset_masked() than the fallback in sys/_atomic_subword.h. There's also an override for _atomic_fcmpset_masked_word(), which may or may not be necessary, and is unused for powerpc. (cherry picked from commit d0bdb11139424b9dcfe3b73cd5a003055382de03) --- sys/powerpc/include/atomic.h | 32 ++++++++++++++++++++++++++++++++ sys/sys/_atomic_subword.h | 4 ++++ 2 files changed, 36 insertions(+) diff --git a/sys/powerpc/include/atomic.h b/sys/powerpc/include/atomic.h index 788e7520d7bc..2510160a402a 100644 --- a/sys/powerpc/include/atomic.h +++ b/sys/powerpc/include/atomic.h @@ -612,6 +612,38 @@ atomic_cmpset_short(volatile u_short *p, u_short cmpval, u_short newval) return (ret); } +#else +static __inline int +atomic_cmpset_masked(uint32_t *p, uint32_t cmpval, uint32_t newval, + uint32_t mask) +{ + int ret; + uint32_t tmp; + + __asm __volatile ( + "1:\tlwarx %2, 0, %2\n\t" /* load old value */ + "and %0, %2, %7\n\t" + "cmplw %4, %0\n\t" /* compare */ + "bne- 2f\n\t" /* exit if not equal */ + "andc %2, %2, %7\n\t" + "or %2, %2, %5\n\t" + "stwcx. %2, 0, %3\n\t" /* attempt to store */ + "bne- 1b\n\t" /* spin if failed */ + "li %0, 1\n\t" /* success - retval = 1 */ + "b 3f\n\t" /* we've succeeded */ + "2:\n\t" + "stwcx. %2, 0, %3\n\t" /* clear reservation (74xx) */ + "li %0, 0\n\t" /* failure - retval = 0 */ + "3:\n\t" + : "=&r" (ret), "=m" (*p), "+&r" (tmp) + : "r" (p), "r" (cmpval), "r" (newval), "m" (*p), + "r" (mask) + : "cr0", "memory"); + + return (ret); +} + +#define _atomic_cmpset_masked_word(a,o,v,m) atomic_cmpset_masked(a, o, v, m) #endif static __inline int diff --git a/sys/sys/_atomic_subword.h b/sys/sys/_atomic_subword.h index fd03ea6a6aed..08e54bf519a9 100644 --- a/sys/sys/_atomic_subword.h +++ b/sys/sys/_atomic_subword.h @@ -63,6 +63,7 @@ ((((__uintptr_t)(p) % 4)) * NBBY) #endif +#ifndef _atomic_cmpset_masked_word /* * Pass these bad boys a couple words and a mask of the bits you care about, * they'll loop until we either succeed or fail because of those bits rather @@ -92,7 +93,9 @@ _atomic_cmpset_masked_word(uint32_t *addr, uint32_t old, uint32_t val, return (ret); } +#endif +#ifndef _atomic_fcmpset_masked_word static __inline int _atomic_fcmpset_masked_word(uint32_t *addr, uint32_t *old, uint32_t val, uint32_t mask) @@ -108,6 +111,7 @@ _atomic_fcmpset_masked_word(uint32_t *addr, uint32_t *old, uint32_t val, *old = (*addr & ~mask) | *old; return (atomic_fcmpset_32(addr, old, (*old & ~mask) | val)); } +#endif static __inline int atomic_cmpset_8(__volatile uint8_t *addr, uint8_t old, uint8_t val)