3 files changed, 90 insertions, 0 deletions

diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index 89022a74faee..b37cb0a9826e 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -384,6 +384,27 @@ acpi_pci_free_irq(struct acpi_prt_entry *entry,
         return irq;
 }
 
+#ifdef CONFIG_X86_IO_APIC
+extern int noioapicquirk;
+
+static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
+{
+        struct pci_bus *bus_it;
+
+        for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
+                if (!bus_it->self)
+                        return 0;
+
+                printk(KERN_INFO "vendor=%04x device=%04x\n", bus_it->self->vendor,
+                                bus_it->self->device);
+
+                if (bus_it->self->irq_reroute_variant)
+                        return bus_it->self->irq_reroute_variant;
+        }
+        return 0;
+}
+#endif /* CONFIG_X86_IO_APIC */
+
 /*
  * acpi_pci_irq_lookup
  * success: return IRQ >= 0
@@ -413,6 +434,41 @@ acpi_pci_irq_lookup(struct pci_bus *bus,
         }
 
         ret = func(entry, triggering, polarity, link);
+
+#ifdef CONFIG_X86_IO_APIC
+        /*
+         * Some chipsets (e.g. intel 6700PXH) generate a legacy INTx when the
+         * IRQ entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel
+         * does during interrupt handling). When this INTx generation cannot be
+         * disabled, we reroute these interrupts to their legacy equivalent to
+         * get rid of spurious interrupts.
+         */
+        if (!noioapicquirk) {
+                switch (bridge_has_boot_interrupt_variant(bus)) {
+                case 0:
+                        /* no rerouting necessary */
+                        break;
+
+                case INTEL_IRQ_REROUTE_VARIANT:
+                        /*
+                         * Remap according to INTx routing table in 6700PXH
+                         * specs, intel order number 302628-002, section
+                         * 2.15.2. Other chipsets (80332, ...) have the same
+                         * mapping and are handled here as well.
+                         */
+                        printk(KERN_INFO "pci irq %d -> rerouted to legacy "
+                                         "irq %d\n", ret, (ret % 4) + 16);
+                        ret = (ret % 4) + 16;
+                        break;
+
+                default:
+                        printk(KERN_INFO "not rerouting irq %d to legacy irq: "
+                                         "unknown mapping\n", ret);
+                        break;
+                }
+        }
+#endif /* CONFIG_X86_IO_APIC */
+
         return ret;
 }
 
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index eb97564316d0..ac634ae2eb08 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -1365,6 +1365,34 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,	0x260b, quirk_intel_pcie_pm);
 
 #ifdef CONFIG_X86_IO_APIC
 /*
+ * Boot interrupts on some chipsets cannot be turned off. For these chipsets,
+ * remap the original interrupt in the linux kernel to the boot interrupt, so
+ * that a PCI device's interrupt handler is installed on the boot interrupt
+ * line instead.
+ */
+static void quirk_reroute_to_boot_interrupts_intel(struct pci_dev *dev)
+{
+        int i;
+
+        if (noioapicquirk)
+                return;
+
+        dev->irq_reroute_variant = INTEL_IRQ_REROUTE_VARIANT;
+
+        printk(KERN_INFO "PCI quirk: reroute interrupts for 0x%04x:0x%04x\n",
+                        dev->vendor, dev->device);
+        return;
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_80333_0,    quirk_reroute_to_boot_interrupts_intel);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_80333_1,    quirk_reroute_to_boot_interrupts_intel);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_ESB2_0,     quirk_reroute_to_boot_interrupts_intel);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_PXH_0,      quirk_reroute_to_boot_interrupts_intel);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_PXH_1,      quirk_reroute_to_boot_interrupts_intel);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_PXHV,       quirk_reroute_to_boot_interrupts_intel);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_80332_0,    quirk_reroute_to_boot_interrupts_intel);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_80332_1,    quirk_reroute_to_boot_interrupts_intel);
+
+/*
  * On some chipsets we can disable the generation of legacy INTx boot
  * interrupts.
  */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d18b1dd49fab..6755cf5ac109 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -117,6 +117,11 @@ enum pci_dev_flags {
         PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG = (__force pci_dev_flags_t) 1,
 };
 
+enum pci_irq_reroute_variant {
+        INTEL_IRQ_REROUTE_VARIANT = 1,
+        MAX_IRQ_REROUTE_VARIANTS = 3
+};
+
 typedef unsigned short __bitwise pci_bus_flags_t;
 enum pci_bus_flags {
         PCI_BUS_FLAGS_NO_MSI   = (__force pci_bus_flags_t) 1,
@@ -194,6 +199,7 @@ struct pci_dev {
         unsigned int    no_d1d2:1;   /* only allow d0 or d3 */
         unsigned int    block_ucfg_access:1;    /* userspace config space access is blocked */
         unsigned int    broken_parity_status:1; /* Device generates false positive parity */
+        unsigned int    irq_reroute_variant:2;  /* device needs IRQ rerouting variant */
         unsigned int    msi_enabled:1;
         unsigned int    msix_enabled:1;
         unsigned int    is_managed:1;