From: Matthew Wilcox <matthew@wil.cx>
To: Anil kumar <anils_r@yahoo.com>
Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org
Subject: Re: dma_pool_alloc restrict < 4GB address
Date: Wed, 12 Nov 2008 20:03:34 -0700 [thread overview]
Message-ID: <20081113030334.GW15439@parisc-linux.org> (raw)
In-Reply-To: <231988.14599.qm@web32401.mail.mud.yahoo.com>
On Wed, Nov 12, 2008 at 02:14:24PM -0800, Anil kumar wrote:
> Is there anyway to restrict the returned bus address(dma address) from dma_poll_alloc to < 4GB ?
> The function returns a dma address(of type dma_addr_t). Is there anyway I can ensure to restrict it to < 4B address.
> I guess we can do that in pci_alloc_consistent as by default it returns 32bit address.
dma_pool_alloc (as described in the documentation ...) allocates memory
using dma_alloc_coherent(). As long as you've set the coherent mask
to 32-bit (or left it alone, since it's 32-bit by default ...), you'll
get 32-bit dma addresses back.
--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
prev parent reply other threads:[~2008-11-13 3:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-12 22:14 dma_pool_alloc restrict < 4GB address Anil kumar
2008-11-13 3:03 ` Matthew Wilcox [this message]
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