From: Sinan Kaya <okaya@codeaurora.org>
To: Steve Wise <swise@opengridcomputing.com>,
netdev@vger.kernel.org, timur@codeaurora.org,
sulrich@codeaurora.org
Cc: linux-arm-msm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
'Steve Wise' <swise@chelsio.com>,
'Doug Ledford' <dledford@redhat.com>,
'Jason Gunthorpe' <jgg@ziepe.ca>,
linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
'Michael Werner' <werner@chelsio.com>,
'Casey Leedom' <leedom@chelsio.com>
Subject: Re: [PATCH v3 18/18] infiniband: cxgb4: Eliminate duplicate barriers on weakly-ordered archs
Date: Sat, 17 Mar 2018 00:03:05 -0400 [thread overview]
Message-ID: <71e37a55-537b-d75a-cfde-f188b7cfce8e@codeaurora.org> (raw)
In-Reply-To: <740c7d45-450e-c9b3-ceed-7bc7fcefbc5a@codeaurora.org>
On 3/16/2018 11:40 PM, Sinan Kaya wrote:
> I'll change writel_relaxed() with __raw_writel() in the series like you suggested
> and also look at your other comments.
I spoke too soon.
Now that I realized, code needs to follow one of the following patterns for correctness
1)
wmb()
writel()/writel_relaxed()
or
2)
wmb()
__raw_wrltel()
mmiowb()
but definitely not
wmb()
__raw_wrltel()
Since #1 == #2, I'll stick to my current implementation of writel_relaxed()
Changing writel() to writel_relaxed() or __raw_writel() isn't enough. PowerPC needs mmiowb()
for correctness. ARM's mmiowb() implementation is empty.
So, there is no one size fits all solution with the current state of affairs.
--
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
next prev parent reply other threads:[~2018-03-17 4:03 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-16 16:16 [PATCH v3 00/18] Eliminate duplicate barriers on weakly-ordered archs Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 01/18] i40e/i40evf: " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 02/18] ixgbe: eliminate " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 03/18] igbvf: " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 04/18] igb: " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 05/18] ixgbevf: keep writel() closer to wmb() Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 06/18] ixgbevf: eliminate duplicate barriers on weakly-ordered archs Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 07/18] drivers: net: cxgb: Eliminate " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 08/18] scsi: hpsa: " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 09/18] fm10k: " Sinan Kaya
2018-03-16 16:30 ` [Intel-wired-lan] " Alexander Duyck
2018-03-16 16:33 ` Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 10/18] net: qla3xxx: " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 11/18] qlcnic: " Sinan Kaya
2018-03-19 20:10 ` Chopra, Manish
2018-03-16 16:16 ` [PATCH v3 12/18] bnx2x: " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 13/18] net: cxgb4/cxgb4vf: " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 14/18] net: cxgb3: " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 15/18] RDMA/bnxt_re: " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 16/18] IB/mlx4: " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 17/18] RDMA/i40iw: " Sinan Kaya
2018-03-16 16:16 ` [PATCH v3 18/18] infiniband: cxgb4: " Sinan Kaya
2018-03-16 21:05 ` Steve Wise
2018-03-16 21:46 ` Sinan Kaya
2018-03-16 23:05 ` Steve Wise
2018-03-17 3:40 ` Sinan Kaya
2018-03-17 4:03 ` Sinan Kaya [this message]
2018-03-17 4:25 ` Sinan Kaya
2018-03-17 4:30 ` Timur Tabi
2018-03-17 13:23 ` Steve Wise
2018-03-17 13:27 ` David Miller
2018-03-17 15:05 ` Jason Gunthorpe
2018-03-17 18:30 ` Sinan Kaya
2018-03-19 1:48 ` Jason Gunthorpe
2018-03-16 22:13 ` Jason Gunthorpe
2018-03-16 23:04 ` Steve Wise
2018-03-17 4:08 ` Timur Tabi
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