Date: Fri, 26 Jun 2009 13:33:18 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Ingo Molnar <mingo@elte.hu>
Cc: "Pan, Jacob jun" <jacob.jun.pan@intel.com>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       "H. Peter Anvin" <hpa@linux.intel.com>
Subject: Re: [PATCH 3/9] x86/moorestown: add moorestown platform flags
Message-ID: <20090626133318.5b8de81b@lxorguk.ukuu.org.uk>
In-Reply-To: <20090626122254.GA9959@elte.hu>
References: <43F901BD926A4E43B106BF17856F07556412B7E2@orsmsx508.amr.corp.intel.com>
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	<20090626101310.4110a290@lxorguk.ukuu.org.uk>
	<20090626093859.GA12571@elte.hu>
	<20090626111603.758ec7fb@lxorguk.ukuu.org.uk>
	<20090626110429.GB12446@elte.hu>
	<20090626125653.5e30bae4@lxorguk.ukuu.org.uk>
	<20090626122254.GA9959@elte.hu>
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> That's a pretty bogus claim - on x86 a bootloader generally knows 
> very little about 'what it is running on'. We do most of the 
> enumeration in early platform code and retrieve information via 
> standard BIOS interfaces.

Stop thinking about existing x86 PC systems running grub for a bit.
Highly embedded systems usually boot from ROM firmware direct into the
kernel. They have a very good idea what they are running on because they
were flashed specifically for the device.

I'm not worried about PC/ISA v PC/MCA v Voyager v CBus v CompaqSMP v
Intel MP 1.4 SMP v PCI v PCI/X v PCI Express v OLPC v Voyager etc, we can
clearly tell all those apart via bus probing. But those are all basically
a PC.

> > How about "they tried other methods and they didn't work"
> 
> The thing is, you are trying to defend a v1 patch-set here that is 
> really indefensible: it's ugly and deficient in numerous smaller and 
> larger details. I outlined numerous deficiencies already - and i'll 
> review v2 too to see what else is there to fix.

No I'm trying to understand what you actually want the thing to look like.

Are we talking

/* Fixed struct not pointer for speed */
struct platform_ops platform_ops;
memcpy(platform_ops, platform_op_list[detect_platform_type()],
					sizeof(struct platform_ops));

platform->add_private_resources();
platform->timer_foo();
platfomr->timer_bar();

or

platform->init();
timer = platform->timer;

timer->begin()

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