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Subject: Re: [PATCH v3 08/11] nvme-pci: Use PCI p2pmem subsystem to manage the
 CMB
To:     Logan Gunthorpe <logang@deltatee.com>,
        linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
        linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org,
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Cc:     Stephen Bates <sbates@raithlin.com>,
        Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
        Keith Busch <keith.busch@intel.com>,
        Sagi Grimberg <sagi@grimberg.me>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Jason Gunthorpe <jgg@mellanox.com>,
        Max Gurtovoy <maxg@mellanox.com>,
        Dan Williams <dan.j.williams@intel.com>,
        =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= <jglisse@redhat.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Alex Williamson <alex.williamson@redhat.com>
References: <20180312193525.2855-1-logang@deltatee.com>
 <20180312193525.2855-9-logang@deltatee.com>
 <4b08ec0b-76f4-4b67-a38b-5a1940c4c40d@codeaurora.org>
From:   Sinan Kaya <okaya@codeaurora.org>
Message-ID: <08950833-d199-fd2b-06f6-9e585c183b86@codeaurora.org>
Date:   Mon, 12 Mar 2018 21:58:21 -0400
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On 3/12/2018 9:55 PM, Sinan Kaya wrote:
> On 3/12/2018 3:35 PM, Logan Gunthorpe wrote:
>> -	if (nvmeq->sq_cmds_io)
> 
> I think you should keep the code as it is for the case where
> (!nvmeq->sq_cmds_is_io && nvmeq->sq_cmds_io)

Never mind. I misunderstood the code.


> 
> You are changing the behavior for NVMe drives with CMB buffers.
> You can change the if statement here with the statement above.
> 
>> -		memcpy_toio(&nvmeq->sq_cmds_io[tail], cmd, sizeof(*cmd));
>> -	else
>> -		memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd));
>> +	memcpy(&nvmeq->sq_cmds[tail], cmd, sizeof(*cmd));
>>  
> 
> 


-- 
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.