Date: Tue, 9 Mar 2021 05:55:15 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: f279cbcbdf76 - releng/13.0 - atomic: add atomic_interrupt_fence() Message-ID: <202103090555.1295tFLk020222@gitrepo.freebsd.org>
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The branch releng/13.0 has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=f279cbcbdf765cb1f3e419605efeb3c397b6c806 commit f279cbcbdf765cb1f3e419605efeb3c397b6c806 Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2021-02-23 22:12:29 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2021-03-09 05:54:33 +0000 atomic: add atomic_interrupt_fence() Approved by: re (gjb) (cherry picked from commit e2494f7561c852951d8ac567314f5e12f19ee7af) --- share/man/man9/atomic.9 | 13 ++++++++++++- sys/sys/atomic_common.h | 2 ++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/share/man/man9/atomic.9 b/share/man/man9/atomic.9 index 39a4fa9c6f96..397a8fcd6b18 100644 --- a/share/man/man9/atomic.9 +++ b/share/man/man9/atomic.9 @@ -22,7 +22,7 @@ .\" .\" $FreeBSD$ .\" -.Dd August 18, 2019 +.Dd February 24, 2021 .Dt ATOMIC 9 .Os .Sh NAME @@ -31,6 +31,7 @@ .Nm atomic_cmpset , .Nm atomic_fcmpset , .Nm atomic_fetchadd , +.Nm atomic_interrupt_fence , .Nm atomic_load , .Nm atomic_readandclear , .Nm atomic_set , @@ -59,6 +60,8 @@ .Fc .Ft <type> .Fn atomic_fetchadd_<type> "volatile <type> *p" "<type> v" +.Ft void +.Fn atomic_interrupt_fence "void" .Ft <type> .Fn atomic_load_[acq_]<type> "volatile <type> *p" .Ft <type> @@ -292,6 +295,14 @@ release stores, by separating access from ordering, they can sometimes facilitate more efficient implementations of synchronization primitives. For example, they can be used to avoid executing a memory barrier until a memory access shows that some condition is satisfied. +.Ss Interrupt Fence Operations +The +.Fn atomic_interrupt_fence() +function establishes ordering between its call location and any interrupt +handler executing on the same CPU. +It is modeled after the similar C11 function +.Fn atomic_signal_fence() , +and adapted for the kernel environment. .Ss Multiple Processors In multiprocessor systems, the atomicity of the atomic operations on memory depends on support for cache coherence in the underlying architecture. diff --git a/sys/sys/atomic_common.h b/sys/sys/atomic_common.h index 48f0a8b8939c..403b3de8a092 100644 --- a/sys/sys/atomic_common.h +++ b/sys/sys/atomic_common.h @@ -78,4 +78,6 @@ #define atomic_load_consume_ptr(p) \ ((__typeof(*p)) atomic_load_acq_ptr((uintptr_t *)p)) +#define atomic_interrupt_fence() __compiler_membar() + #endif
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