linux-kernel - Re: [RFCv3 2/2] dma-buf: add helpers for sharing attacher constraints with dma-parms

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:	Tue, 3 Feb 2015 14:37:15 +0000
From:	Russell King - ARM Linux <linux@....linux.org.uk>
To:	Rob Clark <robdclark@...il.com>
Cc:	Sumit Semwal <sumit.semwal@...aro.org>,
	LKML <linux-kernel@...r.kernel.org>,
	"linux-media@...r.kernel.org" <linux-media@...r.kernel.org>,
	DRI mailing list <dri-devel@...ts.freedesktop.org>,
	Linaro MM SIG Mailman List <linaro-mm-sig@...ts.linaro.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	Linaro Kernel Mailman List <linaro-kernel@...ts.linaro.org>,
	Tomasz Stanislawski <stanislawski.tomasz@...glemail.com>,
	Robin Murphy <robin.murphy@....com>,
	Marek Szyprowski <m.szyprowski@...sung.com>,
	Daniel Vetter <daniel@...ll.ch>
Subject: Re: [RFCv3 2/2] dma-buf: add helpers for sharing attacher
 constraints with dma-parms

On Tue, Feb 03, 2015 at 09:04:03AM -0500, Rob Clark wrote:
> Since I'm stuck w/ an iommu, instead of built in mmu, my plan was to
> drop use of dma-mapping entirely (incl the current call to dma_map_sg,
> which I just need until we can use drm_cflush on arm), and
> attach/detach iommu domains directly to implement context switches.
> At that point, dma_addr_t really has no sensible meaning for me.

So how do you intend to import from a subsystem which only gives you
the dma_addr_t?

If you aren't passing system memory, you have no struct page.  You can't
fake up a struct page.  What this means is that struct scatterlist can't
represent it any other way.

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.
--
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/