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Date:	Thu, 12 Oct 2006 13:37:51 +0100
From:	Thiemo Seufer <ths@networkno.de>
To:	Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc:	Atsushi Nemoto <anemo@mba.ocn.ne.jp>, ralf@linux-mips.org,
	linux-mips@linux-mips.org, fbuihuu@gmail.com
Subject: Re: [PATCH 1/5] Make __pa() uses CPHYSADDR() if really needed
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References: <452CFC95.1080806@innova-card.com> <20061012.003007.08076055.anemo@mba.ocn.ne.jp> <452D1567.1050706@innova-card.com> <20061012.190559.96685979.nemoto@toshiba-tops.co.jp> <452E2BB2.2090601@innova-card.com>
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Franck Bui-Huu wrote:
> Atsushi Nemoto wrote:
> > On Wed, 11 Oct 2006 18:01:43 +0200, Franck Bui-Huu <vagabon.xyz@gmail.com> wrote:
> >>> __pa() is used in many place indirectly via virt_to_page().
> >> what about make virt_to_page() use virt_to_phys() instead ?
> > 
> > No objection for virt_to_phys(), but I found other __pa() usages in
> > kernel.
> > 
> > drivers/char/mem.c:       && addr >= __pa(high_memory);
> > drivers/char/mem.c:     return addr >= __pa(high_memory);
> > drivers/char/mem.c:     if (addr + count > __pa(high_memory))
> > drivers/char/mem.c:     pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT;
> > 
> > So __pa() should handle >512MB address unless we change all __pa() usages.
> 
> weird, I really thought that __pa() shouldn't be used by drivers...
> Let see what people on lkml think about this usage, you'll be CC'ed
> if you want to.

I guess /dev/mem is allowed to as an exception.


Thiemo