From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Hollis Blanchard <hollisb@us.ibm.com>
Cc: linuxppc-dev@ozlabs.org, yanok@emcraft.com,
kvm-ppc@vger.kernel.org, dwg@au1.ibm.com
Subject: Re: [PATCH] [v3] powerpc/4xx: work around CHIP11 errata in a more PAGE_SIZE-friendly way
Date: Wed, 12 Nov 2008 15:37:43 +1100 [thread overview]
Message-ID: <1226464663.13515.1.camel@pasglop> (raw)
In-Reply-To: <700c59731cf97778d3a4.1226448406@localhost.localdomain>
On Tue, 2008-11-11 at 18:06 -0600, Hollis Blanchard wrote:
> The current CHIP11 errata truncates the device tree memory node, and subtracts
> (hardcoded) 4096 bytes. This breaks kernels with larger PAGE_SIZE, since the
> bootmem allocator assumes that total memory is a multiple of PAGE_SIZE.
>
> Instead, use a device tree memory reservation to reserve only the 256 bytes
> actually affected by the errata, leaving the total memory size unaltered.
>
> Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
While I prefer this approach, won't it break kexec ?
I don't understand why we don't just have a bit of code in the kernel
itself that reserve that page on 44x at boot time and be done with it.
It's like we are trying to be too smart and over-engineer the solution.
Cheers,
Ben.
next prev parent reply other threads:[~2008-11-12 4:38 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-12 0:06 [PATCH] [v3] powerpc/4xx: work around CHIP11 errata in a more PAGE_SIZE-friendly way Hollis Blanchard
2008-11-12 0:09 ` David Gibson
2008-11-12 4:37 ` Benjamin Herrenschmidt [this message]
2008-11-12 11:31 ` Josh Boyer
2008-11-12 11:52 ` Benjamin Herrenschmidt
2008-11-12 15:11 ` Hollis Blanchard
2008-11-12 20:44 ` Benjamin Herrenschmidt
2008-11-12 20:53 ` Josh Boyer
2008-11-13 19:54 ` Hollis Blanchard
-- strict thread matches above, loose matches on Subject: below --
2008-11-14 17:25 Milton Miller
2008-11-14 17:29 ` Milton Miller
2008-11-14 22:09 ` Hollis Blanchard
2008-11-18 20:33 ` Hollis Blanchard
2008-11-24 20:07 ` Hollis Blanchard
2008-11-25 0:10 ` Michael Ellerman
2008-11-25 17:10 ` Milton Miller
2008-11-25 21:17 ` Hollis Blanchard
2008-11-25 21:53 ` Hollis Blanchard
2008-11-25 23:43 ` Michael Ellerman
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