From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Daney Subject: Re: [PATCH v6 4/5] MIPS: Octeon: Setup irq_domains for interrupts. Date: Sat, 03 Mar 2012 21:09:32 -0800 Message-ID: <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> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4F527285.1020500-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Rob Herring Cc: "linux-mips-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org" , David Daney , "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "ralf-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org" , Rob Herring List-Id: devicetree@vger.kernel.org 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. > > Ultimately, for DT boot you should use of_irq_init to scan the dts, and > then create a linear domain for each interrupt controller node. You may > need to decide on linear vs. legacy at runtime based on having a DT node > pointer or not. Perhaps, but we need to take the first step before gradually arriving at some Ultimate Solution. We will also need to handle irq controllers with 2^20 sparsely populated hwirq values, so linear domains will probably be out of the question there. David Daney