From: Robert Hancock <hancockr@shaw.ca>
To: "V.Radhakrishnan" <rk@atr-labs.com>
Cc: Sanka Piyaratna <cesanka@yahoo.com>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
linux-kernel@vger.kernel.org
Subject: Re: PCIe device driver question
Date: Wed, 30 Jul 2008 13:21:29 -0600 [thread overview]
Message-ID: <4890BF39.6060608@shaw.ca> (raw)
In-Reply-To: <fa.42mxuHHJP7XQmYeyxNoEC/NFUHA@ifi.uio.no>
V.Radhakrishnan wrote:
>>> am testing this in an X86_64 architecture machine with 4 GB of RAM. I
>>> am able to successfully dma data into any memory (dma) address >
>>> 0x0000_0001_0000_0000.
>
> How can you DMA "successfully" into this address which is > 4 GB when
> you have only 4 GB RAM ? Or am I missing something ?
The MMIO and other reserved memory space at the top of the 32-bit memory
space will cause the top part of memory to be relocated above 4GB.
next parent reply other threads:[~2008-07-30 19:21 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <fa.PmBLCqOb4Xo53y3W9hAdnsU50Og@ifi.uio.no>
[not found] ` <fa.42mxuHHJP7XQmYeyxNoEC/NFUHA@ifi.uio.no>
2008-07-30 19:21 ` Robert Hancock [this message]
2008-07-31 13:11 ` V.Radhakrishnan
2008-07-31 17:37 ` Robert Hancock
2008-07-31 18:47 ` V.Radhakrishnan
2008-07-31 18:52 ` Robert Hancock
2008-07-31 20:47 ` V.Radhakrishnan
2008-07-31 9:58 Sanka Piyaratna
-- strict thread matches above, loose matches on Subject: below --
2008-07-30 22:55 Sanka Piyaratna
2008-07-31 8:44 ` Robert Hancock
[not found] <fa.+kKL98uFtvbcX3ymh2HlJuUDVwY@ifi.uio.no>
2008-07-30 19:24 ` Robert Hancock
2008-07-30 16:09 Sanka Piyaratna
2008-07-30 16:51 ` V.Radhakrishnan
2008-07-30 16:55 ` Alan Cox
2008-07-30 16:00 Sanka Piyaratna
2008-07-30 15:47 ` Alan Cox
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