Hi, In the course of adding PIRQ routing support for Nikolai's FinALi system I realised we need to have some infrastructure for the indirectly accessed configuration space implemented by some chipsets as well as Cyrix CPUs and also included with the Intel MP spec for the IMCR register via port I/O space locations 0x22/0x23. With that in place I implemented PIRQ support for the Intel PCEB/ESC combined EISA southbridge using the same scheme to access the relevant registers and for the final remaining Intel chipset of the era, that is the i420EX. While at it I chose to rewrite ELCR register accesses to avoid using magic numbers scattered across our code and use proper macros like with the remaining PIC registers, and while at it again I noticed and fixed a number of typos: s/ECLR/ELCR/. Since there are mechanical dependencies between the patches (except for typo fixes) I chose to send them as a series rather than individually, though 3/6 depends on: <https://lore.kernel.org/patchwork/patch/1452772/> necessarily as well, the fate of which is currently unclear to me. See individual change descriptions for details. Nikolai: for your system only 1/6 and 2/6 are required, though you are free to experiment with all the patches. Mind that 3/6 mechanically depends on the earlier change for the SIO PIRQ router referred above. In any case please use the debug patch for PCI code as well as the earlier patches for your other system and send the resulting bootstrap log for confirmation. Ideally this would be verified with PCI interrupt sharing, but for that you'd have to track down one or more multifunction option cards (USB 2.0 interfaces with legacy 1.1 functions or serial/parallel multi-I/O cards are good candidates, but of course there are more) or option devices with PCI-to-PCI bridges, and then actually use some of these devices as well. Any interrupt sharing will be reported, e.g.: pci 0000:00:07.0: SIO/PIIX/ICH IRQ router [8086:7000] pci 0000:00:11.0: PCI INT A -> PIRQ 63, mask deb8, excl 0c20 pci 0000:00:11.0: PCI INT A -> newirq 0 PCI: setting IRQ 11 as level-triggered pci 0000:00:11.0: found PCI INT A -> IRQ 11 pci 0000:00:11.0: sharing IRQ 11 with 0000:00:07.2 pci 0000:02:00.0: using bridge 0000:00:11.0 INT A to get INT A pci 0000:00:11.0: sharing IRQ 11 with 0000:02:00.0 pci 0000:02:01.0: using bridge 0000:00:11.0 INT B to get INT A pci 0000:02:02.0: using bridge 0000:00:11.0 INT C to get INT A pci 0000:03:00.0: using bridge 0000:00:11.0 INT A to get INT A pci 0000:00:11.0: sharing IRQ 11 with 0000:03:00.0 pci 0000:04:00.0: using bridge 0000:00:11.0 INT B to get INT A pci 0000:04:00.3: using bridge 0000:00:11.0 INT A to get INT D pci 0000:00:11.0: sharing IRQ 11 with 0000:04:00.3 pci 0000:06:05.0: using bridge 0000:00:11.0 INT D to get INT A pci 0000:06:08.0: using bridge 0000:00:11.0 INT C to get INT A pci 0000:06:08.1: using bridge 0000:00:11.0 INT D to get INT B pci 0000:06:08.2: using bridge 0000:00:11.0 INT A to get INT C pci 0000:00:11.0: sharing IRQ 11 with 0000:06:08.2 -- a lot of sharing and swizzling here. :) You'd most definitely need: <https://lore.kernel.org/patchwork/patch/1454747/> for that though, as I can't imagine PCI BIOS 2.1 PIRQ routers to commonly enumerate devices behind PCI-to-PCI bridges, given that they fail to cope with more complex bus topologies created by option devices in the first place. Maciej
