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Date:   Thu, 27 Jan 2022 10:57:30 +0100
From:   "hch@lst.de" <hch@lst.de>
To:     "yangx.jy@fujitsu.com" <yangx.jy@fujitsu.com>
Cc:     Ira Weiny <ira.weiny@intel.com>, Jason Gunthorpe <jgg@nvidia.com>,
        "lizhijian@fujitsu.com" <lizhijian@fujitsu.com>,
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Subject: Re: [RFC PATCH v2 2/2] RDMA/rxe: Support RDMA Atomic Write
 operation
Message-ID: <20220127095730.GA14946@lst.de>
References: <20220113030350.2492841-3-yangx.jy@fujitsu.com> <20220117131624.GB7906@nvidia.com> <61E673EA.60900@fujitsu.com> <20220118123505.GF84788@nvidia.com> <7dfed756-42a7-b6f7-3473-1348479d30db@fujitsu.com> <20220119123635.GH84788@nvidia.com> <022be340-a49a-1e94-5fb8-1c77f06fecc2@cn.fujitsu.com> <20220121125837.GV84788@nvidia.com> <20220121160654.GC773547@iweiny-DESK2.sc.intel.com> <b3b322be-a718-5fb8-11e2-05ee783f1086@fujitsu.com>
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On Thu, Jan 27, 2022 at 09:37:59AM +0000, yangx.jy@fujitsu.com wrote:
> Do you mean we have to consider that some allocated pages come from high 
> memory?
>
> I think INFINIBAND_VIRT_DMA kconfig[1] has ensured that all allocated 
> pages have a kernel virtual address.

rxe and siw depend on INFINIBAND_VIRT_DMA which depends on !HIGHMEM,
so you don't need kmap here at all.

> In this case, is it OK to call page_address() directly?

Yes.