Messages in this thread | | | Subject | Re: Multiple MSI | From | Benjamin Herrenschmidt <> | Date | Thu, 03 Jul 2008 19:17:00 +1000 |
| |
> Some years ago, we had discussions about getting rid of IRQ numbers > altogether, or at least the requirement to have device drivers know > about them. Does anyone remember what happened to that idea?
I think it's not totally dead. Last I heard, someone (jgarzik ?) was slowly, bit by bit, removing the dependencies on the irq argument on irq handlers which is one step in the direction.
> I think the concept was that you pass around struct irq_desc pointers > that may or may not be dynamically allocated by the interrupt controller > code.
Yup. There are still a few hard dependencies on numbers left and right tho. The main issue is old userspace tied to the layout of things like /proc/interrupts though I'd be happy to special case the 16 "legacy" interrupts (like we do on powerpc in our remapping layer) and only show these here ...
> Another simplification that should really help here is encapsulating > request_irq() per subsystem so that you can do something like > > int my_irq(struct pci_dev *dev); > err = pci_request_irq(pci_dev, &my_irq, IRQF_SHARED); > > Most PCI drivers should be trivial to convert to this model. If you want > to have multiple MSI/MSI-X interrupts for one PCI device with this model, > you'd need to introduce the number back as an offset, I guess.
Might indeed be a good idea.
Cheers, Ben.
| |