From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 09 Mar 2012 06:57:20 +0100 (CET) Received: from mail-iy0-f177.google.com ([209.85.210.177]:63652 "EHLO mail-iy0-f177.google.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S1903554Ab2CIF5O (ORCPT ); Fri, 9 Mar 2012 06:57:14 +0100 Received: by iaky10 with SMTP id y10so2163019iak.36 for ; Thu, 08 Mar 2012 21:57:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=sender:from:subject:to:cc:in-reply-to:references:date:message-id :x-gm-message-state; bh=1eFwJkmi3K14bhFU7Tr2XdRcewgUhCTmu79I16XM5ag=; b=BM/wU7oPLpsqp2Br27K1ukdtzH/W+Zq5idoYujB1XF2BG4S2bKj7SVeKExJiPvqp61 oZKFWaDZMPcTvVGRDU3eFHb/zZ6Kg0fVwNJ7g/1kCXM1J/0ROoQQf+NuRckU6/9fRwSt /w4JSZWqeEbAlCROz3itGtacM/LEpOUGQMRcxyChtYPdbWEA8GqCZiJxs2F6vDb2dJIi oG25vZKqSInw4ch24hJPH9QPCdoDQBN52VaGd0dVfLElEcg49k3VqEDCd8r119Keb51U XhGcjgsWkTBEDH24hZ9Wr0+yoL81ykoQZr0FN/tPR+vRyAyDo1CFiaM7VkfTXm603uq5 gppQ== Received: by 10.42.73.136 with SMTP id s8mr1228750icj.10.1331272627746; Thu, 08 Mar 2012 21:57:07 -0800 (PST) Received: from localhost (S0106d8b37715ee14.cg.shawcable.net. [68.146.14.168]) by mx.google.com with ESMTPS id k3sm697737igq.1.2012.03.08.21.57.05 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 08 Mar 2012 21:57:06 -0800 (PST) Received: by localhost (Postfix, from userid 1000) id 465823E0901; Thu, 8 Mar 2012 22:57:04 -0700 (MST) From: Grant Likely Subject: Re: [PATCH v6 4/5] MIPS: Octeon: Setup irq_domains for interrupts. To: David Daney , Rob Herring Cc: David Daney , David Daney , "linux-mips@linux-mips.org" , "ralf@linux-mips.org" , "devicetree-discuss@lists.ozlabs.org" , Rob Herring , "linux-kernel@vger.kernel.org" In-Reply-To: <4F52F90C.5060306@gmail.com> References: <1330563422-14078-1-git-send-email-ddaney.cavm@gmail.com> <1330563422-14078-5-git-send-email-ddaney.cavm@gmail.com> <4F50D7C2.7080204@gmail.com> <4F510B8E.3070201@cavium.com> <20120302190744.571E03E1C63@localhost> <4F511FB0.5070901@cavium.com> <4F527285.1020500@gmail.com> <4F52F90C.5060306@gmail.com> Date: Thu, 08 Mar 2012 22:57:04 -0700 Message-Id: <20120309055704.465823E0901@localhost> X-Gm-Message-State: ALoCoQnV8Dehe6wBl+naPpriFXIU+p4HNF1Mi3ACE6aNCnkHagjSGIY2bwHZ8/DgRLeA1EBHS0cY X-archive-position: 32622 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: grant.likely@secretlab.ca Precedence: bulk X-list: linux-mips Return-Path: On Sat, 03 Mar 2012 21:09:32 -0800, David Daney wrote: > On 03/03/2012 11:35 AM, Rob Herring wrote: > > On 03/02/2012 01:29 PM, David Daney wrote: > >> On 03/02/2012 11:07 AM, Grant Likely wrote: > >>> +static void __init octeon_irq_set_ciu_mapping(unsigned int irq, > >>> + unsigned int line, > >>> + unsigned int bit, > >>> + struct irq_domain *domain, > >>> struct irq_chip *chip, > >>> irq_flow_handler_t handler) > >>> { > >>> + struct irq_data *irqd; > >>> union octeon_ciu_chip_data cd; > >>> > >>> irq_set_chip_and_handler(irq, chip, handler); > >>> - > >>> cd.l = 0; > >>> cd.s.line = line; > >>> cd.s.bit = bit; > >>> > >>> irq_set_chip_data(irq, cd.p); > >>> octeon_irq_ciu_to_irq[line][bit] = irq; > >>> + > >>> + irqd = irq_get_irq_data(irq); > >>> + irqd->hwirq = line<< 6 | bit; > >>> + irqd->domain = domain; > >>>>> I think the domain code will set these. > >>>> It is my understanding that the domain code only does this for: > >>>> > >>>> o irq_domain_add_legacy() > >>>> > >>>> o irq_create_direct_mapping() > >>>> > >>>> o irq_create_mapping() > >>>> > >>>> We use none of those. So I do it here. > >>>> > >>>> If there is a better way, I am open to suggestions. > >>> irq_create_mapping is called by irq_create_of_mapping() which is > >>> in turn called by irq_of_parse_and-map(). irq_domain always > >>> manages the hwirq and domain values. Driver code cannot manipulate > >>> them manually. > >>> > >> I really must be missing something. > >> > >> Given: > >> > >> 1) I must have a mapping between hwirq and irq that I control so that > >> non-OF code using the OCTEON_IRQ_* constants continues to work. > > Those defines are what you need to work to get rid of. > > We are not starting from a blank slate here. There is a lot of in-tree > code using these symbols. We cannot make them disappear with wishful > thinking. > > The first step is a switch to irq_domains using the existing mappings. > > After we do that, I have patches to transition some drivers to use the > OF mapping via irq_domains. After those are merged, we can work toward > getting rid of OCTEON_IRQ_*. But I think it must be the last step in > the process, not the first. > > > >> 2) irq_create_mapping() will allocate a random irq value if none is > >> already assigned to the hwirq. > >> > >> Therefore: To avoid having random irq values assigned, I must manually > >> assign them. > >> > > So you should be using legacy domain if you need to maintain fixed hwirq > > to linux irq numbers. "linear" is a bit confusing as it doesn't mean > > linear 1:1 irq number assignment, but linear search. > > My reading of Grant's code in linux-next directly contradicts this > statement. There is no code in irqdomain.c, that I can see, that allows > me to have an arbitrary mapping of irq <--> hwirq values. There are 4 kinds of mappings available; legacy, linear, radix and nomap. Ignore nomap and radix; you don't want them. legacy maps a contiguous range of hwirq numbers to a contiguous range of linux irq numbers. To preserve the exising #define mappings but still add DT support, this is the one that you want. The downside is that it requires all the irq_descs to be allocated ahead of time (which probably isn't a problem for you). The linear map has a linear reverse map lookup table that allows arbitrary irq <--> hwirq mappings. This mapping is preferred, but it doesn't work if you need to preserve #defined irq mappings. g.