From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.micromemory.com (ip67-95-226-82.z226-95-67.customer.algx.net [67.95.226.82]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 76581DDF11 for ; Thu, 24 May 2007 02:13:50 +1000 (EST) Received: from [192.168.0.90] by micromemory.com (MDaemon PRO v9.5.6) with ESMTP id md50000412587.msg for ; Wed, 23 May 2007 09:13:46 -0700 Subject: Re: Porting RapidIO from ppc arch to powerpc arch in support of MPC8641D From: Phil Terry To: segher@kernel.crashing.org In-Reply-To: <0389b4398a09293e6b6e0e4304a81ebe@kernel.crashing.org> References: <1179862732.25914.40.camel@pterry-fc6.micromemory.com> <46B96294322F7D458F9648B60E15112C234AE6@zch01exm26.fsl.freescale.net> <0389b4398a09293e6b6e0e4304a81ebe@kernel.crashing.org> Content-Type: text/plain Date: Wed, 23 May 2007 09:13:42 -0700 Message-Id: <1179936822.11247.37.camel@pterry-fc6.micromemory.com> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org Reply-To: pterry@micromemory.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2007-05-23 at 18:00 +0200, Segher Boessenkool wrote: > >>> interrupts = <30 1 31 1 32 1 35 1 36 1 37 1 38 1>; > >>> > >> Do you really use all of this interrupts? In my test, three <32 2 35 2 > >> 36 2> are okay, and the sense is 2. > > > > I think we need to list all the interrupts possible from RIO, not just > > the > > ones the driver happens to use. > > Yes exactly; the device tree describes the hardware, not > the way that Linux (or any other OS) happens to use it. So a law is a bit like a BAR in PCI, its a configuration by software of the memory map determining which accesses are directed at the hardware. Unlike PCI its not something we can go around probing the hardware for and then doling out memory space to them. Its purely up to software as a whole to decide its system wide memory map. Its not that the device "needs" x amount of memory to work, its a case of for your application how much of your memory would you like this device to handle for you. Is this something the dts as a central, early boottime thing should be in charge of, ie telling the kernel how to organize its total memory map? Excuse the noobie questions but I haven't been able to work out the provenance of the open firmware stuff, and the resolution between the ppc32, ppc64, powerpc, apple, ibm, freescale, etc., camps on how this stuff should be used from the archives, too much noise to signal. Cheers Phil > > The same holds for the "law", "doorbells", and "mailboxes" > properties -- I have no clue whether those are hardware > properties or what else, you guys figure it out :-) > > > Segher > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@ozlabs.org > https://ozlabs.org/mailman/listinfo/linuxppc-dev > >