>From: Marc Zyngier [mailto:marc.zyng...@arm.com] >Sent: Friday, December 18, 2015 1:21 PM
>> I need this for my per CPU irqs such timer and IPI which do not come >> from some external device but from CPUs. For these IRQs I am calling >> to irq_create_mapping() from my platform at arch/arc and at that point >> I got no irqdomain and using irq_find_host() is not good since I got >> no device_node (at most I can have DT root). >That's a problem. You should never do that for your timer (doing a request_irq >will do the right thing, and that's what your timer driver already does). Please be more specific, from all that I wrote what is the problem? When I use request_irq() it fail without the mapping and mapping fail without a domain. Never do what? What should I do then? >As for initializing your IPIs, they are usually outside of the IRQ space, so >you should handle them separately (and get your irqchip to initialize them). I am handling all my IRQs within same irqchip, which is the only one I have. So I am not sure what you expect here. Please be more elaborate. >> >> Another thing I'm not seeing here is where is the interrupt actually taken. >> This code only contains the EOI part, but not the ACK side, as well as the >> reverse lookup hwirq -> irq). Where is that code? >> >> ACK is an optional handler and is not needed by my platform. >> I will add comment that since my IRQs are EOI based I do not need an ACK. >What I'm talking about is not the irq_ack method that the irqchip can provide, >but the action your perform on your interrupt controller to extract the hwirq >number and find out what corresponding Linux interrupt has fired. >> >> I do not understand reverse lookup remark, where is it missing? >> Could you point me to an example for such reverse lookup? >See for example: >https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/irqchip/irq-sun4i.c#n136 >This is the function (sun4i_handle_irq) that is executed almost immediately >after the IRQ is asserted. The CPU reads the hwirq from the interrupt >controller, and use handle_domain_irq() to call the corresponding handler (by >doing a lookup in the domain). >I couldn't find out in your platform code where you are doing that. OK, this is seem much like exclusively ARM stuff. Note that I am working with ARC (seem alike) here and we do not define CONFIG_HANDLE_DOMAIN_IRQ and do not implement set_handle_irq(). So for ARC this reverse mapping is something we can leave without (maybe because we are kind of a legacy domain). Note that this patch is part of a set I introduce to ARC as a new platform. You can view my tree and the patch set at: https://github.com/EZchip/linux/commits/EZ-arc-for-next-basic-reviewd-DO-NOT-COMMENT -Noam -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
