Date: Mon, 25 Jan 2021 22:42:36 GMT From: Mateusz Guzik <mjg@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 054ce2b03710 - main - atomic: add stub atomic_load_consume_ptr Message-ID: <202101252242.10PMgaWJ026291@gitrepo.freebsd.org>
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The branch main has been updated by mjg: URL: https://cgit.FreeBSD.org/src/commit/?id=054ce2b0371042c0dbc4b3ab1d7e7795ad75d51e commit 054ce2b0371042c0dbc4b3ab1d7e7795ad75d51e Author: Mateusz Guzik <mjg@FreeBSD.org> AuthorDate: 2021-01-25 20:09:41 +0000 Commit: Mateusz Guzik <mjg@FreeBSD.org> CommitDate: 2021-01-25 22:40:15 +0000 atomic: add stub atomic_load_consume_ptr --- sys/sys/_cscan_atomic.h | 5 +++++ sys/sys/atomic_common.h | 8 ++++++++ 2 files changed, 13 insertions(+) diff --git a/sys/sys/_cscan_atomic.h b/sys/sys/_cscan_atomic.h index 3bd9455102b1..aed96580e1e4 100644 --- a/sys/sys/_cscan_atomic.h +++ b/sys/sys/_cscan_atomic.h @@ -236,6 +236,11 @@ void kcsan_atomic_thread_fence_seq_cst(void); __retptr; \ }) #define atomic_load_acq_ptr kcsan_atomic_load_acq_ptr +#define atomic_load_consume_ptr(x) ({ \ + __typeof(*x) __retptr; \ + __retptr = (void *)kcsan_atomic_load_acq_ptr((volatile uintptr_t *)(x));\ + __retptr; \ +}) #define atomic_readandclear_ptr kcsan_atomic_readandclear_ptr #define atomic_set_ptr kcsan_atomic_set_ptr #define atomic_set_acq_ptr kcsan_atomic_set_acq_ptr diff --git a/sys/sys/atomic_common.h b/sys/sys/atomic_common.h index 4c29d132c369..48f0a8b8939c 100644 --- a/sys/sys/atomic_common.h +++ b/sys/sys/atomic_common.h @@ -70,4 +70,12 @@ (*(volatile uint64_t *)(p) = (uint64_t)(v)) #endif +/* + * Currently all architectures provide acquire and release fences on their own, + * but they don't provide consume. Kludge below allows relevant code to stop + * openly resorting to the stronger acquire fence, to be sorted out. + */ +#define atomic_load_consume_ptr(p) \ + ((__typeof(*p)) atomic_load_acq_ptr((uintptr_t *)p)) + #endif
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