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Message-ID: <1386356996.7375.120.camel@snotra.buserror.net>
Subject: Re: [PATCH] powerpc 8xx: Loading kernels over 8Mbytes without
 CONFIG_PIN_TLB
From: Scott Wood <scottwood@freescale.com>
To: Christophe Leroy <christophe.leroy@c-s.fr>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>, <linux-kernel@vger.kernel.org>,
        <linuxppc-dev@lists.ozlabs.org>
Date: Fri, 6 Dec 2013 13:09:56 -0600
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On Wed, 2013-11-27 at 12:04 +0100, Christophe Leroy wrote:
> Today, the only way to load kernels whose size is greater than 8Mbytes is to
> activate CONFIG_PIN_TLB. Otherwise, the physical memory initially mapped is
> limited to 8Mbytes. This patch sets up 24 Mbytes of initial memory regardless
> of whether CONFIG_PIN_TLB is active or not. It allows to load "big" kernels
> (for instance when activating CONFIG_LOCKDEP_SUPPORT) without having
> to activate CONFIG_PIN_TLB.

So, what happens on boards with less than 24M memory present?  Even if
you avoid explicitly referencing those addresses, what if there is a
speculative access -- or does 8xx not do that?

-Scott