Date: Mon, 6 Aug 2018 08:40:02 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r337374 - head/sys/compat/linuxkpi/common/include/asm Message-ID: <201808060840.w768e2gl023307@repo.freebsd.org>
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Author: hselasky Date: Mon Aug 6 08:40:02 2018 New Revision: 337374 URL: https://svnweb.freebsd.org/changeset/base/337374 Log: Implement atomic_long_cmpxchg() function in the LinuxKPI. Submitted by: Johannes Lundberg <johalun0@gmail.com> MFC after: 1 week Sponsored by: Mellanox Technologies Modified: head/sys/compat/linuxkpi/common/include/asm/atomic-long.h Modified: head/sys/compat/linuxkpi/common/include/asm/atomic-long.h ============================================================================== --- head/sys/compat/linuxkpi/common/include/asm/atomic-long.h Mon Aug 6 08:35:16 2018 (r337373) +++ head/sys/compat/linuxkpi/common/include/asm/atomic-long.h Mon Aug 6 08:40:02 2018 (r337374) @@ -81,6 +81,21 @@ atomic_long_xchg(atomic_long_t *v, long val) return atomic_swap_long(&v->counter, val); } +static inline long +atomic_long_cmpxchg(atomic_long_t *v, long old, long new) +{ + long ret = old; + + for (;;) { + if (atomic_cmpset_long(&v->counter, old, new)) + break; + ret = READ_ONCE(v->counter); + if (ret != old) + break; + } + return (ret); +} + static inline int atomic_long_add_unless(atomic_long_t *v, long a, long u) {
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