From: James Bottomley <James.Bottomley@SteelEye.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: "Ju, Seokmann" <Seokmann.Ju@lsil.com>,
"Ju, Seokmann" <Seokmann.Ju@engenio.com>,
linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org
Subject: Re: Question: how to map SCSI data DMA address to virtual address?
Date: Thu, 02 Mar 2006 11:22:12 -0600 [thread overview]
Message-ID: <1141320132.3238.20.camel@mulgrave.il.steeleye.com> (raw)
In-Reply-To: <20060302170915.GA31316@infradead.org>
On Thu, 2006-03-02 at 17:09 +0000, Christoph Hellwig wrote:
> For each sg list entry do something like:
>
> buffer = kmap_atomic(sg->page, KM_USER0) + sg->offset;
> <access buffer>
> kunmap_atomic(buffer - sg->offset, KM_USER0);
Remember too that the data might not necessarily be valid without a
flush depending on where it has come from (or where it is going). See
the dma_sync_sg_for_device/cpu.
James
next prev parent reply other threads:[~2006-03-02 17:22 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-02 16:53 Question: how to map SCSI data DMA address to virtual address? Ju, Seokmann
2006-03-02 16:58 ` Arjan van de Ven
2006-03-02 17:09 ` linux-os (Dick Johnson)
2006-03-02 18:49 ` Jens Axboe
2006-03-02 20:03 ` linux-os (Dick Johnson)
2006-03-02 20:14 ` Jens Axboe
2006-03-02 17:09 ` Christoph Hellwig
2006-03-02 17:22 ` James Bottomley [this message]
-- strict thread matches above, loose matches on Subject: below --
2006-03-02 17:04 Ju, Seokmann
2006-03-02 17:21 Ju, Seokmann
2006-03-02 21:04 Ju, Seokmann
2006-03-02 21:32 ` linux-os (Dick Johnson)
2006-03-02 21:42 ` James Bottomley
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1141320132.3238.20.camel@mulgrave.il.steeleye.com \
--to=james.bottomley@steeleye.com \
--cc=Seokmann.Ju@engenio.com \
--cc=Seokmann.Ju@lsil.com \
--cc=hch@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox