From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 7 Feb 2011 19:30:53 +1100 From: David Gibson To: Dave Kleikamp Subject: Re: [PATCH V2 4/6] powerpc/44x: don't use tlbivax on AMP systems Message-ID: <20110207083053.GB28943@yookeroo> References: <1296586126-32765-1-git-send-email-shaggy@linux.vnet.ibm.com> <1296586126-32765-5-git-send-email-shaggy@linux.vnet.ibm.com> <20110202230844.GG3032@yookeroo> <1296690839.12290.108.camel@shaggy-w500> <20110203050351.GK3032@yookeroo> <1296774957.14077.23.camel@shaggy-w500> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1296774957.14077.23.camel@shaggy-w500> Cc: linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Feb 03, 2011 at 05:15:57PM -0600, Dave Kleikamp wrote: > On Thu, 2011-02-03 at 16:03 +1100, David Gibson wrote: > > On Wed, Feb 02, 2011 at 05:53:59PM -0600, Dave Kleikamp wrote: > > > On Thu, 2011-02-03 at 10:08 +1100, David Gibson wrote: > > > > On Tue, Feb 01, 2011 at 12:48:44PM -0600, Dave Kleikamp wrote: > > > > > Since other OS's may be running on the other cores don't use tlbivax > > > > > > > > [snip] > > > > > +#ifdef CONFIG_44x > > > > > +void __init early_init_mmu_44x(void) > > > > > +{ > > > > > + unsigned long root = of_get_flat_dt_root(); > > > > > + if (of_flat_dt_is_compatible(root, "ibm,47x-AMP")) > > > > > + amp = 1; > > > > > +} > > > > > +#endif /* CONFIG_44x */ > > > > > > > > A test against a hardcoded compatible string seems a nasty way to do > > > > this. Maybe we should define a new boolean property for the root > > > > node. > > > > > > I'm not crazy about this string, but I needed something in the device > > > tree to key off of. Freescale has something similar (i.e. > > > MPC8572DS-CAMP), so I chose to follow their example. I'd be happy to > > > replace it with a boolean property. Any objection to just using > > > "amp"? > > > > Bit too short, I think. I'd suggest either spelling out > > 'asymmetric-multiprocessor' or 'cooperative-partition' (a more > > accurate term, IMO). > > I could be wrong, but I thought the A stands for Asynchronous, not > Asymmetric. I thought Asymmetric means that different types of tasks > run on the secondary processors, as on the Cell. Yeah, I thought so too, but Freescale at least seem to use it this way. 'Asynchronous' would make even less sense. > Anyway, going with > 'cooperative-partition' would avoid that confusion. > > Shaggy -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson