linux-kernel - Re: [PATCH 1/5] dma: create dma_generic_alloc/free

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 26 Oct 2009 20:26:39 -0600
From:	Alex Williamson <alex.williamson@...com>
To:	Paul Mundt <lethal@...ux-sh.org>
Cc:	dwmw2@...radead.org, iommu@...ts.linux-foundation.org,
	linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org
Subject: Re: [PATCH 1/5] dma: create dma_generic_alloc/free_coherent()

On Tue, 2009-10-27 at 09:57 +0900, Paul Mundt wrote:
> On Mon, Oct 26, 2009 at 05:24:58PM -0600, Alex Williamson wrote:
> > Move dma_generic_alloc_coherent() out of x86 code and create
> > corresponding dma_generic_free_coherent() for symmetry.  These
> > can then be used by IOMMU drivers attempting to implement
> > passthrough mode.
> > 
> Except that dma_generic_alloc_coherent() is only "generic" for platforms
> with consistent DMA. Everyone else will need a cacheflush and potentially
> a remap. It's not even obvious from looking at the consistent DMA
> platforms that they'll be able to use it out of the box due to expecting
> something other than page_address(), which all suggests that this is
> better off remaining an x86-only routine.
> 
> This is also making changes to the DMA-API without any documentation
> updates and without consulting with any other architecture people.

Ok, thanks for the feedback.  Let's forget this patch and I'll see how
amenable David is to doing something within intel-iommu since it only
supports platforms with consistent DMA.  Thanks,

Alex

--
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/