linux-kernel - Re: [PATCH 0/9] TI DMM-TILER driver

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]

Message-Id: <201012161843.48262.arnd@arndb.de>
Date:	Thu, 16 Dec 2010 18:43:48 +0100
From:	Arnd Bergmann <arnd@...db.de>
To:	David Sin <davidsin@...com>
Cc:	linux-arm-kernel@...ts.infradead.org,
	dri-devel@...ts.freedesktop.org, Greg KH <greg@...ah.com>,
	Russell King <rmk@....linux.org.uk>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org, linux-omap@...r.kernel.org
Subject: Re: [PATCH 0/9] TI DMM-TILER driver

On Thursday 16 December 2010 18:37:38 David Sin wrote:
> I'm not sure exactly how DRM/GEM works..  What functionality do you think is 
> overlapping?  The main feature, aside from reduced page accesses, of the DMM 
> hw block is to provide physically contiguous 2 dimensional memory blocks for 
> image and video processing.  This hw sits between the interconnect and the 
> ext memory interface in the OMAP, and contains an MMU-like address traslator 
> for "virtually" physically contiguous memory and sdram pages.

As far as I can tell, both DMM and GEM at a high level manage objects
in video memory. The IOMMU that you have on the Omap hardware seems
to resemble the GART that sits between PC-style video cards and main
memory.

I don't know any details, but google quickly finds
http://lwn.net/Articles/283798/ with a description of the
initial GEM design. My main thought when looking over the
DMM code was that this should not be tied too closely to a
specific hardware, and GEM seems to be an existing abstraction
that may fit what you need.

	Arnd
--
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/