linux-kernel - RE: [PATCH 8/9] dspbridge: add map support for big buffers

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: <20100826215554N.fujita.tomonori@lab.ntt.co.jp>
Date:	Thu, 26 Aug 2010 21:56:45 +0900
From:	FUJITA Tomonori <fujita.tomonori@....ntt.co.jp>
To:	fernando.lugo@...com
Cc:	fujita.tomonori@....ntt.co.jp, linux-omap@...r.kernel.org,
	linux-kernel@...r.kernel.org, ohad@...ery.com,
	hiroshi.doyu@...ia.com, ameya.palande@...ia.com,
	felipe.contreras@...ia.com
Subject: RE: [PATCH 8/9] dspbridge: add map support for big buffers

On Thu, 26 Aug 2010 07:38:26 -0500
"Guzman Lugo, Fernando" <fernando.lugo@...com> wrote:

> >> due to a restriction in scatter gather lists, it can
> >> not be created a list for a buffer bigger than 1MB.
> >> This patch is spliting big mappings into 1MB mappings.
> >
> >I don't read the whole thread but the above description is incorrect.
> >
> >Why can't you use scatter gather chaining? You can create a scatter
> >list for a buffer larger than 1MB.
> 
> The thing is that ARM architecture does not support SG chaining. This patch should be
> seen like a workaround until it is fixed in iovmm module.

Fix iovmm module is easier than the workaround?

>From a quick look, arch/arm/plat-omap/iovmm.c does nothing wrong about
scatter gather chaining. arm/arm/mm/dma-mapping.c looks fine too about
it. Maybe just defining ARCH_HAS_SG_CHAIN works?
--
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/