Date: Wed, 1 Jan 2014 22:51:19 +0000 (UTC) From: Marcel Moolenaar <marcel@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r260175 - head/sys/ia64/include Message-ID: <201401012251.s01MpJFM074443@svn.freebsd.org>
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Author: marcel Date: Wed Jan 1 22:51:19 2014 New Revision: 260175 URL: http://svnweb.freebsd.org/changeset/base/260175 Log: Implement atomic_swap_<type>. The operation was documented and implemented partially (both from a type and architecture perspective) on 2013-08-21 and got used in ZFS with revision 260150 (zfeature.c) and since ZFS is supported on ia64, the lack of having atomic_swap became problem. Modified: head/sys/ia64/include/atomic.h Modified: head/sys/ia64/include/atomic.h ============================================================================== --- head/sys/ia64/include/atomic.h Wed Jan 1 22:49:37 2014 (r260174) +++ head/sys/ia64/include/atomic.h Wed Jan 1 22:51:19 2014 (r260175) @@ -386,4 +386,32 @@ atomic_fetchadd_long(volatile u_long *p, return (value); } +/* + * <type> atomic_swap_<type>(volatile <type> *p, <type> v); + */ + +static __inline uint32_t +atomic_swap_32(volatile uint32_t *p, uint32_t v) +{ + uint32_t r; + + __asm __volatile ("xchg4 %0 = %3, %2;;" : "=r"(r), "=m"(*p) : + "r"(v), "m"(*p) : "memory"); + return (r); +} + +static __inline uint64_t +atomic_swap_64(volatile uint64_t *p, uint64_t v) +{ + uint64_t r; + + __asm __volatile ("xchg8 %0 = %3, %2;;" : "=r"(r), "=m"(*p) : + "r"(v), "m"(*p) : "memory"); + return (r); +} + +#define atomic_swap_int atomic_swap_32 +#define atomic_swap_long atomic_swap_64 +#define atomic_swap_ptr atomic_swap_64 + #endif /* ! _MACHINE_ATOMIC_H_ */
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