On 03/03/2017 17:41, Marc Zyngier wrote: > On Fri, Mar 03 2017 at 11:26:27 am GMT, Mason <slash.tmp@xxxxxxx> wrote: >> On 01/03/2017 17:36, Marc Zyngier wrote: >> >>> Mason: while the kernel has generic support for dealing with MSI, there >>> is not standardization at the interrupt controller level, so you do have >>> to write your own driver, and wire it in the rest of the framework. >>> >>> I suggest you look at things like drivers/pci/host/pcie-altera-msi.c, >>> which has an extremely simple implementation. You can use this as a >>> starting point for your own driver. >> >> Thanks Marc, >> >> I'll have a close look at the Altera driver. >> >> I'm having a hard time understanding 3 different kinds of interrupts: >> >> 1. MSI (message-signalled interrupts) >> 2. legacy interrupts >> 3. custom interrupts > > [...] > >> I suppose the interrupt controller I'm supposed to write needs >> to handle all 3 types of interrupts? > > That's entirely up to you. INTx is the bare minimum. That's going to be a problem. Rev 1 of the PCIe controller does not support legacy interrupts at all. > MSI is what people > actually need. The rest has more to do with configuring your host > controller, but only you know about it (and I'm not really interested in > the gory details of how this particular HW works). I was under the impression that some of the error interrupts might be required for proper PCIe functionality. > I mentioned the Altera driver because it is a very simple example of an > MSI controller driver that uses the generic MSI domains. It doesn't care > about INTx, nor host controller management interrupts (that's handled > separately). OK, MSI support is all I need to start with, so I'll try my best to decipher the cryptic intc API, without melting my remaining neuron. Regards.
