src/patches/suse-2.6.27.25/patches.arch/x86-acpi-reroute-PCI-interrupt-to-legacy-boot-interrupt.patch

   1 From: Stefan Assmann <sassmann@suse.de>
   2 Subject: pci, acpi: reroute PCI interrupt to legacy boot interrupt equivalent
   3
   4 Some chipsets (e.g. intel 6700PXH) generate a legacy INTx when the
   5 IRQ entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel
   6 does during interrupt handling). On chipsets where this INTx generation
   7 cannot be disabled, we reroute the valid interrupts to their legacy
   8 equivalent to get rid of spurious interrupts that might otherwise bring
   9 down (vital) interrupt lines through spurious interrupt detection in
  10 note_interrupt().
  11
  12 This patch benefited from discussions with Alexander Graf, Torsten Duwe,
  13 Ihno Krumreich, Daniel Gollub, Hannes Reinecke. The conclusions we drew
  14 and the patch itself are the authors' responsibility alone.
  15
  16 Signed-off-by: Stefan Assmann <sassmann@suse.de>
  17 Signed-off-by: Olaf Dabrunz <od@suse.de>
  18 Signed-off-by: Ingo Molnar <mingo@elte.hu>
  19 ---
  20  drivers/acpi/pci_irq.c |   56 +++++++++++++++++++++++++++++++++++++++++++++++++
  21  drivers/pci/quirks.c   |   26 ++++++++++++++++++++++
  22  include/linux/pci.h    |    6 +++++
  23  3 files changed, 88 insertions(+)
  24
  25 --- a/drivers/acpi/pci_irq.c
  26 +++ b/drivers/acpi/pci_irq.c
  27 @@ -384,6 +384,27 @@ acpi_pci_free_irq(struct acpi_prt_entry
  28         return irq;
  29  }
  30
  31 +#ifdef CONFIG_X86_IO_APIC
  32 +extern int noioapicquirk;
  33 +
  34 +static int bridge_has_boot_interrupt_variant(struct pci_bus *bus)
  35 +{
  36 +       struct pci_bus *bus_it;
  37 +
  38 +       for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) {
  39 +               if (!bus_it->self)
  40 +                       return 0;
  41 +
  42 +               printk(KERN_INFO "vendor=%04x device=%04x\n", bus_it->self->vendor,
  43 +                               bus_it->self->device);
  44 +
  45 +               if (bus_it->self->irq_reroute_variant)
  46 +                       return bus_it->self->irq_reroute_variant;
  47 +       }
  48 +       return 0;
  49 +}
  50 +#endif /* CONFIG_X86_IO_APIC */
  51 +
  52  /*
  53   * acpi_pci_irq_lookup
  54   * success: return IRQ >= 0
  55 @@ -413,6 +434,41 @@ acpi_pci_irq_lookup(struct pci_bus *bus,
  56         }
  57
  58         ret = func(entry, triggering, polarity, link);
  59 +
  60 +#ifdef CONFIG_X86_IO_APIC
  61 +       /*
  62 +        * Some chipsets (e.g. intel 6700PXH) generate a legacy INTx when the
  63 +        * IRQ entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel
  64 +        * does during interrupt handling). When this INTx generation cannot be
  65 +        * disabled, we reroute these interrupts to their legacy equivalent to
  66 +        * get rid of spurious interrupts.
  67 +        */
  68 +        if (!noioapicquirk) {
  69 +               switch (bridge_has_boot_interrupt_variant(bus)) {
  70 +               case 0:
  71 +                       /* no rerouting necessary */
  72 +                       break;
  73 +
  74 +               case INTEL_IRQ_REROUTE_VARIANT:
  75 +                       /*
  76 +                        * Remap according to INTx routing table in 6700PXH
  77 +                        * specs, intel order number 302628-002, section
  78 +                        * 2.15.2. Other chipsets (80332, ...) have the same
  79 +                        * mapping and are handled here as well.
  80 +                        */
  81 +                       printk(KERN_INFO "pci irq %d -> rerouted to legacy "
  82 +                                        "irq %d\n", ret, (ret % 4) + 16);
  83 +                       ret = (ret % 4) + 16;
  84 +                       break;
  85 +
  86 +               default:
  87 +                       printk(KERN_INFO "not rerouting irq %d to legacy irq: "
  88 +                                        "unknown mapping\n", ret);
  89 +                       break;
  90 +               }
  91 +       }
  92 +#endif /* CONFIG_X86_IO_APIC */
  93 +
  94         return ret;
  95  }
  96
  97 --- a/drivers/pci/quirks.c
  98 +++ b/drivers/pci/quirks.c
  99 @@ -1425,6 +1425,32 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_IN
 100
 101  #ifdef CONFIG_X86_IO_APIC
 102  /*
 103 + * Boot interrupts on some chipsets cannot be turned off. For these chipsets,
 104 + * remap the original interrupt in the linux kernel to the boot interrupt, so
 105 + * that a PCI device's interrupt handler is installed on the boot interrupt
 106 + * line instead.
 107 + */
 108 +static void quirk_reroute_to_boot_interrupts_intel(struct pci_dev *dev)
 109 +{
 110 +       if (noioapicquirk)
 111 +               return;
 112 +
 113 +       dev->irq_reroute_variant = INTEL_IRQ_REROUTE_VARIANT;
 114 +
 115 +       printk(KERN_INFO "PCI quirk: reroute interrupts for 0x%04x:0x%04x\n",
 116 +                       dev->vendor, dev->device);
 117 +       return;
 118 +}
 119 +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_80333_0,    quirk_reroute_to_boot_interrupts_intel);
 120 +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_80333_1,    quirk_reroute_to_boot_interrupts_intel);
 121 +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_ESB2_0,     quirk_reroute_to_boot_interrupts_intel);
 122 +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_PXH_0,      quirk_reroute_to_boot_interrupts_intel);
 123 +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_PXH_1,      quirk_reroute_to_boot_interrupts_intel);
 124 +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_PXHV,       quirk_reroute_to_boot_interrupts_intel);
 125 +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_80332_0,    quirk_reroute_to_boot_interrupts_intel);
 126 +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL,   PCI_DEVICE_ID_INTEL_80332_1,    quirk_reroute_to_boot_interrupts_intel);
 127 +
 128 +/*
 129   * On some chipsets we can disable the generation of legacy INTx boot
 130   * interrupts.
 131   */
 132 --- a/include/linux/pci.h
 133 +++ b/include/linux/pci.h
 134 @@ -133,6 +133,11 @@ enum pci_dev_flags {
 135         PCI_DEV_FLAGS_NO_D3 = (__force pci_dev_flags_t) 2,
 136  };
 137
 138 +enum pci_irq_reroute_variant {
 139 +       INTEL_IRQ_REROUTE_VARIANT = 1,
 140 +       MAX_IRQ_REROUTE_VARIANTS = 3
 141 +};
 142 +
 143  typedef unsigned short __bitwise pci_bus_flags_t;
 144  enum pci_bus_flags {
 145         PCI_BUS_FLAGS_NO_MSI   = (__force pci_bus_flags_t) 1,
 146 @@ -217,6 +222,7 @@ struct pci_dev {
 147         unsigned int    no_msi:1;       /* device may not use msi */
 148         unsigned int    block_ucfg_access:1;    /* userspace config space access is blocked */
 149         unsigned int    broken_parity_status:1; /* Device generates false positive parity */
 150 +       unsigned int    irq_reroute_variant:2;  /* device needs IRQ rerouting variant */
 151         unsigned int    msi_enabled:1;
 152         unsigned int    msix_enabled:1;
 153         unsigned int    is_managed:1;