[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20100710151111.GD10080@8bytes.org>
Date: Sat, 10 Jul 2010 17:11:11 +0200
From: Joerg Roedel <joro@...tes.org>
To: Zach Pfeffer <zpfeffer@...eaurora.org>
Cc: Andi Kleen <andi@...stfloor.org>,
Daniel Walker <dwalker@...eaurora.org>,
Randy Dunlap <randy.dunlap@...cle.com>, mel@....ul.ie,
linux-mm@...ck.org, linux-kernel@...r.kernel.org,
linux-arm-msm@...r.kernel.org, linux-omap@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org
Subject: Re: [RFC 3/3] mm: iommu: The Virtual Contiguous Memory Manager
On Thu, Jul 01, 2010 at 11:17:34PM -0700, Zach Pfeffer wrote:
> Andi Kleen wrote:
> > Hmm? dma_map_* does not change any CPU mappings. It only sets up
> > DMA mapping(s).
>
> Sure, but I was saying that iommu_map() doesn't just set up the IOMMU
> mappings, its sets up both the iommu and kernel buffer mappings.
What do you mean by kernel buffer mappings?
> > That assumes that all the IOMMUs on the system support the same page table
> > format, right?
>
> Actually no. Since the VCMM abstracts a page-table as a Virtual
> Contiguous Region (VCM) a VCM can be associated with any device,
> regardless of their individual page table format.
The IOMMU-API abstracts a page-table as a domain which can also be
associated with any device (behind an iommu).
Joerg
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists