From mboxrd@z Thu Jan  1 00:00:00 1970
From: "H. Peter Anvin" <hpa@zytor.com>
Date: Tue, 28 Jul 2015 21:06:21 +0000
Subject: Re: [PATCH 0/8] Use correctly the Xen memory terminologies in Linux
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References: <1438095769-2560-1-git-send-email-julien.grall@citrix.com>
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To: Julien Grall <julien.grall@citrix.com>, xen-devel@lists.xenproject.org
Cc: linux-fbdev@vger.kernel.org, x86@kernel.org, netdev@vger.kernel.org, Jiri Slaby <jslaby@suse.com>, Thomas Gleixner <tglx@linutronix.de>, Russell King <linux@arm.linux.org.uk>, linux-scsi@vger.kernel.org, Tomi Valkeinen <tomi.valkeinen@ti.com>, stefano.stabellini@eu.citrix.com, Ingo Molnar <mingo@redhat.com>, linux-input@vger.kernel.org, Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>, ian.campbell@citrix.com, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>, "James E.J. Bottomley" <JBottomley@odin.com>, Boris Ostrovsky <boris.ostrovsky@oracle.com>, linux-arm-kernel@lists.infradead.org, Juergen Gross <jgross@suse.com>, Wei Liu <wei.liu2@citrix.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Dmitry Torokhov <dmitry.torokhov@gmail.com>, linux-kernel@vger.kernel.org, David Vrabel <david.vrabel@citrix.com>, linux-api@vger.kernel.org, linuxppc-dev@lists.ozlabs.or

On 07/28/2015 08:02 AM, Julien Grall wrote:
> Hi all,
> 
> This patch series aims to use the memory terminologies described in
> include/linux/mm.h [1] for Linux xen code.
> 
> Linux is using mistakenly MFN when GFN is meant, I suspect this is because the
> first support of Xen was for PV. This has brought some misimplementation
> of memory helpers on ARM and make the developper confused about the expected
> behavior.
> 
> For instance, with pfn_to_mfn, we expect to get a MFN based on the name.
> Although, if we look at the implementation on x86, it's returning a GFN.
> Most of the callers are also using it this way.
> 
> The first 2 patches of this series is ARM related in order to remove
> PV specific helpers which should not be used and fixing the implementation of
> pfn_to_mfn.
> 
> The rest of the series is here rename most of the usage in the common code
> of MFN to GFN. I also took the opportunity to replace most of the call to
> pfn_to_gfn in the common code by page_to_gfn avoid construction such
> as pfn_to_gfn(page_to_pfn(...).
> 
> Note the one xen-blkfront will be dropped by 64K series [2], I can include it
> if necessary.
> 

Can we actually get some documentation for Xen before starting to change
names around?

	-hpa