From mboxrd@z Thu Jan  1 00:00:00 1970
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: [PATCH 01/35] lmb: prepare x86 to use lmb to replace early_res
Date: Tue, 18 May 2010 08:02:29 +1000
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To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai <yinghai.lu@oracle.com>, Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>, Andrew Morton <akpm@linux-foundation.org>, David Miller <davem@davemloft.net>, Linus Torvalds <torvalds@linux-foundation.org>, Johannes Weiner <hannes@cmpxchg.org>, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org

On Mon, 2010-05-17 at 11:03 -0700, H. Peter Anvin wrote:
> On 05/14/2010 01:09 AM, Benjamin Herrenschmidt wrote:
> > 
> > No. That is not the point. Read the rest of my email !
> > 
> > We need to -sanitize- those errors. _Maybe_ exposing LMB_ERROR is the
> > right way to do so, but in that case, we need to make -all- function use
> > the same error code. Right now, some fail with 0 and some with
> > LMB_ERROR.
> > 
> 
> Using errnos like the rest of the kernel seems like the right thing to
> do, IMO.

Maybe. The allocator/find functions return a physical address. If we all
agree that a physical address between -PAGE_SIZE and 0 is never valid,
then we can overlay the negative errno codes like we do for pointers.

I'll have a look at that, it shouldn't be very hard.

Cheers,
Ben.