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From: Balbir Singh <bsingharora@gmail.com>
Date: Wed, 18 Jan 2017 07:23:45 +0530
To: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>,
 Michael Ellerman <mpe@ellerman.id.au>,
 Benjamin Herrenschmidt <benh@kernel.crashing.org>,
 Paul Mackerras <paulus@samba.org>, linuxppc-dev@lists.ozlabs.org,
 "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
 Alistair Popple <apopple@au1.ibm.com>
Subject: Re: [PATCH v5 4/4] powerpc/mm: unstub radix__vmemmap_remove_mapping()
Message-ID: <20170118015345.GA18959@localhost.localdomain>
References: <1484593666-8001-1-git-send-email-arbab@linux.vnet.ibm.com>
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On Tue, Jan 17, 2017 at 12:36:53PM -0600, Reza Arbab wrote:
> On Tue, Jan 17, 2017 at 12:55:13PM +0530, Balbir Singh wrote:
> > On Mon, Jan 16, 2017 at 01:07:46PM -0600, Reza Arbab wrote:
> > > Use remove_pagetable() and friends for radix vmemmap removal.
> > > 
> > > We do not require the special-case handling of vmemmap done in the x86
> > > versions of these functions. This is because vmemmap_free() has already
> > > freed the mapped pages, and calls us with an aligned address range.
> > > 
> > > So, add a few failsafe WARNs, but otherwise the code to remove physical
> > > mappings is already sufficient for vmemmap.
> > 
> > I wonder if we really need them?
> 
> Not sure what the guideline is for a "this shouldn't happen" WARN. It could
> save us some grief, should our vmemmap code ever start calling with an
> unaligned range, like it does on x86.
>

Fair enough

Acked-by: Balbir Singh <bsingharora@gmail.com>