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x86/PCI: Handle PIRQ routing tables with no router device given

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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 <macro@orcam.me.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nikolai Zhubr <zhubr.2@gmail.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2203302018570.9038@angie.orcam.me.uk
This commit is contained in:
Maciej W. Rozycki 2022-03-31 08:11:01 +01:00 committed by Thomas Gleixner
parent 5d64089aa4
commit ac7cd5e16d
1 changed files with 44 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
arch/x86/pci/irq.c
View File

@ -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 */
}