Module Name: src
Committed By: riastradh
Date: Sun Dec 19 12:25:05 UTC 2021
Modified Files:
src/sys/external/bsd/common/include/asm: barrier.h
Log Message:
linux: Define mb/wmb/rmb for x86.
These are _not_ SMP barriers; on Linux they specifically mean
mfence/sfence/lfence. Although membar_sync and mb agree, and
membar_consumer and rmb agree, membar_producer and wmb _do not_ agree
on x86 -- Linux's wmb is specifically sfence, which is important only
for unusual memory types, whereas our membar_producer is limited to
ordinary memory.
To generate a diff of this commit:
cvs rdiff -u -r1.8 -r1.9 src/sys/external/bsd/common/include/asm/barrier.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/external/bsd/common/include/asm/barrier.h
diff -u src/sys/external/bsd/common/include/asm/barrier.h:1.8 src/sys/external/bsd/common/include/asm/barrier.h:1.9
--- src/sys/external/bsd/common/include/asm/barrier.h:1.8 Sun Dec 19 11:02:54 2021
+++ src/sys/external/bsd/common/include/asm/barrier.h Sun Dec 19 12:25:05 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: barrier.h,v 1.8 2021/12/19 11:02:54 riastradh Exp $ */
+/* $NetBSD: barrier.h,v 1.9 2021/12/19 12:25:05 riastradh Exp $ */
/*-
* Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -46,6 +46,11 @@
#define mb() __asm __volatile ("dsb sy" ::: "memory")
#define wmb() __asm __volatile ("dsb st" ::: "memory")
#define rmb() __asm __volatile ("dsb ld" ::: "memory")
+#elif defined(__x86_64__)
+#include <x86/cpufunc.h>
+#define mb() x86_mfence()
+#define wmb() x86_sfence()
+#define rmb() x86_lfence()
#else
#define mb membar_sync
#define wmb membar_producer
