Date: Mon, 23 May 2016 16:19:51 +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: r300517 - head/sys/compat/linuxkpi/common/include/asm Message-ID: <201605231619.u4NGJpki088309@repo.freebsd.org>
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Author: hselasky Date: Mon May 23 16:19:51 2016 New Revision: 300517 URL: https://svnweb.freebsd.org/changeset/base/300517 Log: Implement "atomic_long_add_unless()" in the LinuxKPI and fix the implementation of "atomic_long_inc_not_zero()". Found by: ngie @ 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 May 23 16:12:11 2016 (r300516) +++ head/sys/compat/linuxkpi/common/include/asm/atomic-long.h Mon May 23 16:19:51 2016 (r300517) @@ -41,7 +41,7 @@ typedef struct { #define atomic_long_add(i, v) atomic_long_add_return((i), (v)) #define atomic_long_inc_return(v) atomic_long_add_return(1, (v)) -#define atomic_long_inc_not_zero(v) atomic_long_inc_not_zero(v) +#define atomic_long_inc_not_zero(v) atomic_long_add_unless((v), 1, 0) static inline long atomic_long_add_return(long i, atomic_long_t *v) @@ -73,6 +73,21 @@ atomic_long_dec(atomic_long_t *v) return atomic_fetchadd_long(&v->counter, -1) - 1; } +static inline int +atomic_long_add_unless(atomic_long_t *v, long a, long u) +{ + long c; + + for (;;) { + c = atomic_long_read(v); + if (unlikely(c == u)) + break; + if (likely(atomic_cmpset_long(&v->counter, c, c + a))) + break; + } + return (c != u); +} + static inline long atomic_long_dec_and_test(atomic_long_t *v) {
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