From ac7cd5e16df8696c39e29b03dfedf069a025b822 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Thu, 31 Mar 2022 08:11:01 +0100 Subject: x86/PCI: Handle PIRQ routing tables with no router device given PIRQ routing tables provided by the PCI BIOS usually specify the PCI vendor:device ID as well as the bus address of the device implementing the PIRQ router, e.g.: PCI: Interrupt Routing Table found at 0xc00fde10 [...] PCI: Attempting to find IRQ router for [8086:7000] pci 0000:00:07.0: PIIX/ICH IRQ router [8086:7000] however in some cases they do not, in which case we fail to match the router handler, e.g.: PCI: Interrupt Routing Table found at 0xc00fdae0 [...] PCI: Attempting to find IRQ router for [0000:0000] PCI: Interrupt router not found at 00:00 This is because we always match the vendor:device ID and the bus address literally, even if they are all zeros. Handle this case then and iterate over all PCI devices until we find a matching router handler if the vendor ID given by the routing table is the invalid value of zero: PCI: Attempting to find IRQ router for [0000:0000] PCI: Trying IRQ router for [1039:0496] pci 0000:00:05.0: SiS85C497 IRQ router [1039:0496] Signed-off-by: Maciej W. Rozycki Signed-off-by: Thomas Gleixner Tested-by: Nikolai Zhubr Link: https://lore.kernel.org/r/alpine.DEB.2.21.2203302018570.9038@angie.orcam.me.uk --- arch/x86/pci/irq.c | 64 +++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 44 insertions(+), 20 deletions(-) (limited to 'arch') diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c index ef97b260a556..d4ecf881c0c8 100644 --- a/arch/x86/pci/irq.c +++ b/arch/x86/pci/irq.c @@ -1175,10 +1175,32 @@ static struct pci_dev *pirq_router_dev; * chipset" ? */ +static bool __init pirq_try_router(struct irq_router *r, + struct irq_routing_table *rt, + struct pci_dev *dev) +{ + struct irq_router_handler *h; + + DBG(KERN_DEBUG "PCI: Trying IRQ router for [%04x:%04x]\n", + dev->vendor, dev->device); + + for (h = pirq_routers; h->vendor; h++) { + /* First look for a router match */ + if (rt->rtr_vendor == h->vendor && + h->probe(r, dev, rt->rtr_device)) + return true; + /* Fall back to a device match */ + if (dev->vendor == h->vendor && + h->probe(r, dev, dev->device)) + return true; + } + return false; +} + static void __init pirq_find_router(struct irq_router *r) { struct irq_routing_table *rt = pirq_table; - struct irq_router_handler *h; + struct pci_dev *dev; #ifdef CONFIG_PCI_BIOS if (!rt->signature) { @@ -1197,27 +1219,29 @@ static void __init pirq_find_router(struct irq_router *r) DBG(KERN_DEBUG "PCI: Attempting to find IRQ router for [%04x:%04x]\n", rt->rtr_vendor, rt->rtr_device); - pirq_router_dev = pci_get_domain_bus_and_slot(0, rt->rtr_bus, - rt->rtr_devfn); - if (!pirq_router_dev) { - DBG(KERN_DEBUG "PCI: Interrupt router not found at " - "%02x:%02x\n", rt->rtr_bus, rt->rtr_devfn); - return; + /* Use any vendor:device provided by the routing table or try all. */ + if (rt->rtr_vendor) { + dev = pci_get_domain_bus_and_slot(0, rt->rtr_bus, + rt->rtr_devfn); + if (dev && pirq_try_router(r, rt, dev)) + pirq_router_dev = dev; + } else { + dev = NULL; + for_each_pci_dev(dev) { + if (pirq_try_router(r, rt, dev)) { + pirq_router_dev = dev; + break; + } + } } - for (h = pirq_routers; h->vendor; h++) { - /* First look for a router match */ - if (rt->rtr_vendor == h->vendor && - h->probe(r, pirq_router_dev, rt->rtr_device)) - break; - /* Fall back to a device match */ - if (pirq_router_dev->vendor == h->vendor && - h->probe(r, pirq_router_dev, pirq_router_dev->device)) - break; - } - dev_info(&pirq_router_dev->dev, "%s IRQ router [%04x:%04x]\n", - pirq_router.name, - pirq_router_dev->vendor, pirq_router_dev->device); + if (pirq_router_dev) + dev_info(&pirq_router_dev->dev, "%s IRQ router [%04x:%04x]\n", + pirq_router.name, + pirq_router_dev->vendor, pirq_router_dev->device); + else + DBG(KERN_DEBUG "PCI: Interrupt router not found at " + "%02x:%02x\n", rt->rtr_bus, rt->rtr_devfn); /* The device remains referenced for the kernel lifetime */ } -- cgit v1.2.3