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| author | Stephan Günther <moepi@moepi.net> | 2018-12-16 15:08:21 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-26 11:32:42 +0300 |
| commit | 868152e4ca97b12ae651c4e7cad4ce66cb7529a0 (patch) | |
| tree | c52f9384924a629958c304634eccdd008f667ac0 /drivers/scsi/mpt3sas | |
| parent | 6fa75685aa3ade4de264c06c26aa7b90cdec34f3 (diff) | |
| download | linux-868152e4ca97b12ae651c4e7cad4ce66cb7529a0.tar.xz | |
scsi: mpt3sas: fix memory ordering on 64bit writes
[ Upstream commit 23c3828aa2f84edec7020c7397a22931e7a879e1 ]
With commit 09c2f95ad404 ("scsi: mpt3sas: Swap I/O memory read value back
to cpu endianness"), 64bit writes in _base_writeq() were rewritten to use
__raw_writeq() instad of writeq().
This introduced a bug apparent on powerpc64 systems such as the Raptor
Talos II that causes the HBA to drop from the PCIe bus under heavy load and
being reinitialized after a couple of seconds.
It can easily be triggered on affacted systems by using something like
fio --name=random-write --iodepth=4 --rw=randwrite --bs=4k --direct=0 \
--size=128M --numjobs=64 --end_fsync=1
fio --name=random-write --iodepth=4 --rw=randwrite --bs=64k --direct=0 \
--size=128M --numjobs=64 --end_fsync=1
a couple of times. In my case I tested it on both a ZFS raidz2 and a btrfs
raid6 using LSI 9300-8i and 9400-8i controllers.
The fix consists in resembling the write ordering of writeq() by adding a
mandatory write memory barrier before device access and a compiler barrier
afterwards. The additional MMIO barrier is superfluous.
Signed-off-by: Stephan Günther <moepi@moepi.net>
Reported-by: Matt Corallo <linux@bluematt.me>
Acked-by: Sreekanth Reddy <Sreekanth.Reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/scsi/mpt3sas')
| -rw-r--r-- | drivers/scsi/mpt3sas/mpt3sas_base.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c index 59d7844ee022..b59bba3e6516 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_base.c +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c @@ -3344,8 +3344,9 @@ _base_mpi_ep_writeq(__u64 b, volatile void __iomem *addr, static inline void _base_writeq(__u64 b, volatile void __iomem *addr, spinlock_t *writeq_lock) { + wmb(); __raw_writeq(b, addr); - mmiowb(); + barrier(); } #else static inline void |