Date: Thu, 16 Aug 2018 08:10:11 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r337896 - stable/11/sys/compat/linuxkpi/common/include/asm Message-ID: <201808160810.w7G8ABQT016122@repo.freebsd.org>
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Author: hselasky Date: Thu Aug 16 08:10:11 2018 New Revision: 337896 URL: https://svnweb.freebsd.org/changeset/base/337896 Log: MFC r337374: Implement atomic_long_cmpxchg() function in the LinuxKPI. Submitted by: Johannes Lundberg <johalun0@gmail.com> Sponsored by: Mellanox Technologies Modified: stable/11/sys/compat/linuxkpi/common/include/asm/atomic-long.h Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/compat/linuxkpi/common/include/asm/atomic-long.h ============================================================================== --- stable/11/sys/compat/linuxkpi/common/include/asm/atomic-long.h Thu Aug 16 08:09:26 2018 (r337895) +++ stable/11/sys/compat/linuxkpi/common/include/asm/atomic-long.h Thu Aug 16 08:10:11 2018 (r337896) @@ -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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