From mboxrd@z Thu Jan  1 00:00:00 1970
From: linux@arm.linux.org.uk (Russell King - ARM Linux)
Date: Mon, 4 Feb 2013 15:11:32 +0000
Subject: [PATCHv2 1/2] ARM: dma-mapping: add support for CMA regions
 placed in highmem zone
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On Mon, Feb 04, 2013 at 03:42:26PM +0100, Michal Nazarewicz wrote:
> > On Mon, Feb 04, 2013 at 03:24:51PM +0100, Michal Nazarewicz wrote:
> >> Perhaps it should use lowmem_page_address() then?
> 
> On Mon, Feb 04 2013, Russell King - ARM Linux wrote:
> > It's well defined that page_address() will be non-NULL for lowmem pages.
> > There is nothing wrong with the above.
> 
> It would save on a branch and a function call though.

Depending on the size of struct page, if we care that much, we can probably
enable WANT_PAGE_VIRTUAL which'll make it even cheaper as it's just a
dereference.