On 06/18/2018 02:46 PM, Greg Kurz wrote: > On Mon, 18 Jun 2018 13:31:26 +0200 > Cédric Le Goater <c...@kaod.org> wrote: > >> On 06/18/2018 11:54 AM, Greg Kurz wrote: >>> On Mon, 18 Jun 2018 10:56:55 +0200 >>> Cédric Le Goater <c...@kaod.org> wrote: >>> >>>> [ ... ] >>>> >>>>>>> This is 4 irqs per PHB, hence up to 32 PHBs. Cool, we're currently >>>>>>> limited to 31 PHBs. >>>>>>> >>>>>>>> +#define SPAPR_IRQ_MSI 0x1100 /* Offset of the dynamic range >>>>>>>> covered >>>>>>> >>>>>>> We only support dynamic MSIs with PCI, maybe rename to >>>>>>> SPAPR_IRQ_PCI_MSI ? >>>>>> >>>>>> hmm, no. We could have CAPI devices there. remember ? ;) >>>>>> >>>>> >>>>> Well... OpenCAPI devices are exposed to the OS as PCI devices, so I'm not >>>>> sure we need a CAPI specific range. >>>> >>>> yes. so this range is common to all devices doing dynamic allocation >>>> of IRQs. How should we call it ? >>>> >>>>>>>> + * by the bitmap allocator */ >>>>>>>> >>>>>>> >>>>>>> The range size is hence 1k (XICS_IRQS_SPAPR) for the time being. >>>>>> >>>>>> in fact we could this bogus limit and use spapr->irq_map_nr now. >>>>>> >>>>> >>>>> "we could *missing verb* this bogus limit"... so I'm not sure to >>>>> understand... >>>> >>>> oups. We could use spapr->irq_map_nr instead of XICS_IRQS_SPAPR when >>>> defining : >>>> >>>> _FDT(fdt_setprop_cell(fdt, bus_off, "ibm,pe-total-#msi", >>>> XICS_IRQS_SPAPR)); >>>> >>>> in spapr_pci.c >>>> >>> >>> Ah... yeah, I've always found weird that all PHBs advertise the same number >>> of available MSIs as the total number of irqs for the whole machine. And >>> putting spapr->irq_map_nr looks weird all the same if all PHBs rely on the >>> same bitmap actually. >>> >>> I'm thinking of doing the other way around: keep XICS_IRQS_SPAPR in >>> "ibm,pe-total-#msi" and have one XICS_IRQS_SPAPR sized bitmap per PHB. >> >> That could be the place where to put the msi allocator. >> > > Are you suggesting to move @irq_map and @irq_map_nr to sPAPRPHBState and > to have these setup during PHB realize ? I guess we could do that.
Hmm, I think it's better to keep it under the machine. We only need to define an IRQ number "quantity" per phb and not a specific IRQ number range. The claimed numbers can be machine wide numbers. C.
