From: Andrew Morton <akpm@digeo.com>
To: imran.badr@cavium.com
Cc: root@chaos.analogic.com, "'David S. Miller'" <davem@redhat.com>,
phillips@arcor.de, linux-kernel@vger.kernel.org
Subject: Re: Calculating kernel logical address ..
Date: Mon, 09 Sep 2002 11:08:33 -0700 [thread overview]
Message-ID: <3D7CE3A1.6A17D428@digeo.com> (raw)
In-Reply-To: 019f01c25826$c553f310$9e10a8c0@IMRANPC
Imran Badr wrote:
>
> The virt_to_bus() macro would work only for kernel logical addresses. I am
> trying to find a portable way to figure out the kernel logical address of a
> user buffer so that I could use virt_to_bus() for DMA. The user address is
> mmap'ed from kmalloc'ed buffer in the mmap() entry of my driver. Now when
> the user wants to send this data to the PCI device, it makes an ioctl call
> and give the user address to the driver. Now driver has to figure out the
> kernel logical address for DMA.
>
You can obtain this info by walking the user's pagetables with
get_user_pages(). That give `struct page' pointers, with which
all things are possible.
next prev parent reply other threads:[~2002-09-09 18:04 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-09-09 17:06 Calculating kernel logical address Imran Badr
2002-09-09 17:29 ` Richard B. Johnson
2002-09-09 17:23 ` David S. Miller
2002-09-09 17:34 ` Martin J. Bligh
2002-09-09 17:40 ` Daniel Phillips
2002-09-09 17:31 ` Imran Badr
2002-09-09 18:00 ` Richard B. Johnson
2002-09-09 18:12 ` Imran Badr
2002-09-09 18:27 ` Daniel Phillips
2002-09-09 18:41 ` Imran Badr
2002-09-09 21:55 ` Alan Cox
2002-09-09 22:52 ` Imran Badr
2002-09-09 23:09 ` Alan Cox
2002-09-09 18:13 ` Jesse Barnes
2002-09-09 18:25 ` Daniel Phillips
2002-09-09 19:40 ` Andrew Morton
2002-09-09 20:41 ` Daniel Phillips
2002-09-10 6:43 ` Jens Axboe
2002-09-10 7:12 ` Andrew Morton
2002-09-09 18:42 ` Andrew Morton
2002-09-10 7:03 ` Gerd Knorr
2002-09-09 18:16 ` Kurt Ferreira
2002-09-09 18:17 ` David S. Miller
2002-09-09 18:17 ` Daniel Phillips
2002-09-09 18:43 ` Richard B. Johnson
2002-09-09 18:50 ` Daniel Phillips
2002-09-09 18:57 ` Richard B. Johnson
2002-09-09 18:08 ` Andrew Morton [this message]
2002-09-09 18:23 ` Daniel Phillips
2002-09-09 18:49 ` Imran Badr
2002-09-09 18:46 ` David S. Miller
2002-09-09 19:06 ` Daniel Phillips
2002-09-09 19:14 ` Andrew Morton
2002-09-09 19:23 ` Imran Badr
-- strict thread matches above, loose matches on Subject: below --
2002-09-09 21:19 Manfred Spraul
2002-09-09 21:47 ` Andrew Morton
2002-09-10 17:01 ` Manfred Spraul
2002-09-09 21:02 Manfred Spraul
2002-09-09 21:07 ` Imran Badr
2002-09-06 15:44 Manfred Spraul
2002-09-06 17:13 ` Imran Badr
2002-09-07 1:57 ` Daniel Phillips
2002-09-06 3:23 side-by-side Re: BYTE Unix Benchmarks Version 3.6 Daniel Phillips
2002-09-06 3:34 ` Calculating kernel logical address Imran Badr
2002-09-07 1:44 ` Daniel Phillips
2002-09-08 0:01 ` David S. Miller
2002-09-08 18:44 ` Daniel Phillips
2002-09-09 5:00 ` David S. Miller
2002-09-09 5:17 ` Daniel Phillips
2002-09-09 5:28 ` David S. Miller
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