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From: Scott Wood <oss@buserror.net>
To: Christophe Leroy <christophe.leroy@c-s.fr>, Benjamin Herrenschmidt
 <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Michael
 Ellerman <mpe@ellerman.id.au>, Zhao Qiang <qiang.zhao@nxp.com>, "David
 S.Miller" <davem@davemloft.net>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
 stable@vger.kernel.org
Date: Thu, 11 Aug 2016 18:29:59 -0500
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Subject: Re: [PATCH] soc: fsl/qe: fix Oops on CPM1 (and likely CPM2)
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On Mon, 2016-08-08 at 18:08 +0200, Christophe Leroy wrote:
> Commit 0e6e01ff694ee ("CPM/QE: use genalloc to manage CPM/QE muram")
> has changed the way muram is managed.
> genalloc uses kmalloc(), hence requires the SLAB to be up and running.
> 
> On powerpc 8xx, cpm_reset() is called early during startup.
> cpm_reset() then calls cpm_muram_init() before SLAB is available,
> hence the following Oops.
> 
> cpm_reset() cannot be called during initcalls because the CPM is
> needed for console
> 
> This patch splits cpm_muram_init() in two parts. The first part,
> related to mappings, is kept as cpm_muram_init()
> The second part is named cpm_muram_pool_init() and is called
> the first time cpm_muram_alloc() is used

Why do you need to split it, versus calling the full cpm_muram_init() on
demand?

-Scott