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From: "Michael S. Tsirkin" <mst@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	virtualization@lists.linux-foundation.org
Subject: [PATCH 08/34] asm-generic: smp_store_mb should use smp_mb
Date: Wed, 30 Dec 2015 15:24:47 +0200	[thread overview]
Message-ID: <1451473761-30019-9-git-send-email-mst@redhat.com> (raw)
In-Reply-To: <1451473761-30019-1-git-send-email-mst@redhat.com>

asm-generic variant of smp_store_mb() calls mb() which is stronger
than implied by both the name and the documentation.

smp_store_mb is only used by core kernel code at the moment, so
we know no one mis-uses it for an MMIO barrier.
Make it call smp_mb consistently before some arch-specific
code uses it as such by mistake.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/asm-generic/barrier.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h
index 538f8d1..987b2e0 100644
--- a/include/asm-generic/barrier.h
+++ b/include/asm-generic/barrier.h
@@ -93,7 +93,7 @@
 #endif	/* CONFIG_SMP */
 
 #ifndef smp_store_mb
-#define smp_store_mb(var, value)  do { WRITE_ONCE(var, value); mb(); } while (0)
+#define smp_store_mb(var, value)  do { WRITE_ONCE(var, value); smp_mb(); } while (0)
 #endif
 
 #ifndef smp_mb__before_atomic
-- 
MST

  parent reply	other threads:[~2015-12-30 13:24 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-30 13:24 [PATCH 00/34] arch: barrier cleanup + __smp_XXX barriers for virt Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 01/34] Documentation/memory-barriers.txt: document __smb_mb() Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 02/34] asm-generic: guard smp_store_release/load_acquire Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 03/34] ia64: rename nop->iosapic_nop Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 04/34] ia64: reuse asm-generic/barrier.h Michael S. Tsirkin
2015-12-30 16:41   ` Luck, Tony
2015-12-30 13:24 ` [PATCH 05/34] powerpc: " Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 06/34] s390: " Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 07/34] sparc: " Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin [this message]
2015-12-30 13:44   ` [PATCH 08/34] asm-generic: smp_store_mb should use smp_mb Arnd Bergmann
     [not found]   ` <5946017.BCmPrpGMuh@wuerfel>
2015-12-30 20:30     ` Michael S. Tsirkin
     [not found]     ` <20151230222703-mutt-send-email-mst@redhat.com>
2015-12-30 22:43       ` Arnd Bergmann
2015-12-30 13:24 ` [PATCH 09/34] arm: reuse asm-generic/barrier.h Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 10/34] arm64: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 11/34] metag: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 12/34] mips: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 13/34] x86/um: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 14/34] x86: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 15/34] asm-generic: add __smp_XXX wrappers Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 16/34] powerpc: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 17/34] arm64: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 18/34] arm: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 19/34] blackfin: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 20/34] ia64: " Michael S. Tsirkin
2015-12-30 16:43   ` Luck, Tony
2015-12-30 13:25 ` [PATCH 21/34] metag: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 22/34] mips: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 23/34] s390: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 24/34] sh: define __smp_XXX, fix smp_store_mb for !SMP Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 25/34] sparc: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 26/34] tile: " Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 27/34] xtensa: " Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 28/34] x86: " Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 29/34] Revert "virtio_ring: Update weak barriers to use dma_wmb/rmb" Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 30/34] virtio_ring: update weak barriers to use __smp_XXX Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 31/34] xenbus: use __smp_XXX barriers Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 32/34] xen/io: " Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 33/34] virtio: use __smp_load_acquire/__smp_store_release Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 34/34] virtio_ring: use __smp_store_mb Michael S. Tsirkin
2015-12-30 13:49 ` [PATCH 00/34] arch: barrier cleanup + __smp_XXX barriers for virt Arnd Bergmann
2015-12-30 21:45   ` [PATCH 00/34] arch: barrier cleanup + __smp_xxx " Michael S. Tsirkin
     [not found]   ` <20151230234521-mutt-send-email-mst@redhat.com>
2015-12-30 22:45     ` Arnd Bergmann
     [not found] ` <1451473761-30019-4-git-send-email-mst@redhat.com>
2015-12-30 16:39   ` [PATCH 03/34] ia64: rename nop->iosapic_nop Luck, Tony
     [not found] ` <1451473761-30019-8-git-send-email-mst@redhat.com>
2015-12-30 17:56   ` [PATCH 07/34] sparc: reuse asm-generic/barrier.h David Miller
     [not found]   ` <20151230.125603.75638711551088484.davem@davemloft.net>
2015-12-30 19:55     ` Michael S. Tsirkin
2015-12-30 20:47       ` David Miller
2015-12-30 20:46 ` [PATCH 00/34] arch: barrier cleanup + __smp_xxx barriers for virt David Miller
2015-12-30 21:36   ` Michael S. Tsirkin
     [not found]   ` <20151230224855-mutt-send-email-mst@redhat.com>
2015-12-30 21:59     ` David Miller
     [not found] ` <1451473761-30019-2-git-send-email-mst@redhat.com>
2016-01-04 11:08   ` [PATCH 01/34] Documentation/memory-barriers.txt: document __smb_mb() Stefano Stabellini
     [not found]   ` <alpine.DEB.2.02.1601041104290.19710@kaball.uk.xensource.com>
2016-01-04 11:27     ` Michael S. Tsirkin
     [not found] ` <1451473761-30019-32-git-send-email-mst@redhat.com>
2016-01-04 11:58   ` [PATCH 31/34] xenbus: use __smp_XXX barriers Stefano Stabellini
     [not found] ` <1451473761-30019-33-git-send-email-mst@redhat.com>
2016-01-04 11:59   ` [PATCH 32/34] xen/io: " Stefano Stabellini

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