From: Bas Vermeulen <bvermeul@blackstar.xs4all.nl>
To: Catalin Marinas <catalin.marinas@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: NOMMU - How to reserve 1 MB in top of memory in a clean way
Date: Wed, 06 Apr 2005 17:16:04 +0200 [thread overview]
Message-ID: <1112800564.2687.40.camel@laptop.blackstar.nl> (raw)
In-Reply-To: <tnxzmwc9gun.fsf@arm.com>
On Wed, 2005-04-06 at 15:26, Catalin Marinas wrote:
> Bas Vermeulen <bvermeul@blackstar.xs4all.nl> wrote:
> > I am currently working on the bfinnommu linux port for the BlackFin 533.
> > I need to grab the top 1 MB of memory so I can give it out to drivers
> > that need non-cached memory for DMA operations.
>
> I did this long time ago (on a 2.4 kernel), trying to avoid a hardware
> problem. I re-ordered the zones so that ZONE_DMA came after
> ZONE_NORMAL. Since the DMA memory was quite small (less than 1MB), I
> also put a "break" before "case ZONE_DMA" in the
> build_zonelists_node() functions to avoid the allocation fallback.
This will put me in the zone of 'it ain't ever going to be integrated'.
I'd preferrably find a solution without changing the zones. My ideal
solution would be grabbing pages before they are assigned to a zone, or
at least for the zone to recognize them as used.
Bas Vermeulen
next prev parent reply other threads:[~2005-04-06 15:16 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-04-06 9:50 Bas Vermeulen
2005-04-06 13:26 ` Catalin Marinas
2005-04-06 14:53 ` Richard B. Johnson
2005-04-06 15:05 ` Catalin Marinas
2005-04-06 15:13 ` Bas Vermeulen
2005-04-06 15:16 ` Bas Vermeulen [this message]
2005-04-06 15:56 ` Catalin Marinas
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