Date: Wed, 12 Nov 2008 20:03:34 -0700
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
Message-ID: <20081113030334.GW15439@parisc-linux.org>
References: <231988.14599.qm@web32401.mail.mud.yahoo.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <231988.14599.qm@web32401.mail.mud.yahoo.com>
User-Agent: Mutt/1.5.13 (2006-08-11)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1076
Lines: 20

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."
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/