override_for_missing_acs_capabilities.patch

   1 diff -rupN linux-3.15.old/Documentation/kernel-parameters.txt linux-3.15/Documentation/kernel-parameters.txt
   2 --- linux-3.15.old/Documentation/kernel-parameters.txt  2014-06-08 15:19:54.000000000 -0300
   3 +++ linux-3.15/Documentation/kernel-parameters.txt      2014-06-09 18:05:31.744055580 -0300
   4 @@ -2554,6 +2554,16 @@ bytes respectively. Such letter suffixes
   5                 nomsi   Do not use MSI for native PCIe PME signaling (this makes
   6                         all PCIe root ports use INTx for all services).
   7
   8 +       pcie_acs_override =
   9 +                       [PCIE] Override missing PCIe ACS support for:
  10 +               downstream
  11 +                       All downstream ports - full ACS capabilties
  12 +               multifunction
  13 +                       All multifunction devices - multifunction ACS subset
  14 +               id:nnnn:nnnn
  15 +                       Specfic device - full ACS capabilities
  16 +                       Specified as vid:did (vendor/device ID) in hex
  17 +
  18         pcmv=           [HW,PCMCIA] BadgePAD 4
  19
  20         pd_ignore_unused
  21 diff -rupN linux-3.15.old/drivers/pci/quirks.c linux-3.15/drivers/pci/quirks.c
  22 --- linux-3.15.old/drivers/pci/quirks.c 2014-06-08 15:19:54.000000000 -0300
  23 +++ linux-3.15/drivers/pci/quirks.c     2014-06-09 18:06:36.688743183 -0300
  24 @@ -3384,6 +3384,107 @@ struct pci_dev *pci_get_dma_source(struc
  25         return pci_dev_get(dev);
  26  }
  27
  28 +static bool acs_on_downstream;
  29 +static bool acs_on_multifunction;
  30 +
  31 +#define NUM_ACS_IDS 16
  32 +struct acs_on_id {
  33 +       unsigned short vendor;
  34 +       unsigned short device;
  35 +};
  36 +static struct acs_on_id acs_on_ids[NUM_ACS_IDS];
  37 +static u8 max_acs_id;
  38 +
  39 +static __init int pcie_acs_override_setup(char *p)
  40 +{
  41 +       if (!p)
  42 +               return -EINVAL;
  43 +
  44 +       while (*p) {
  45 +               if (!strncmp(p, "downstream", 10))
  46 +                       acs_on_downstream = true;
  47 +               if (!strncmp(p, "multifunction", 13))
  48 +                       acs_on_multifunction = true;
  49 +               if (!strncmp(p, "id:", 3)) {
  50 +                       char opt[5];
  51 +                       int ret;
  52 +                       long val;
  53 +
  54 +                       if (max_acs_id >= NUM_ACS_IDS - 1) {
  55 +                               pr_warn("Out of PCIe ACS override slots (%d)\n",
  56 +                                       NUM_ACS_IDS);
  57 +                               goto next;
  58 +                       }
  59 +
  60 +                       p += 3;
  61 +                       snprintf(opt, 5, "%s", p);
  62 +                       ret = kstrtol(opt, 16, &val);
  63 +                       if (ret) {
  64 +                               pr_warn("PCIe ACS ID parse error %d\n", ret);
  65 +                               goto next;
  66 +                       }
  67 +                       acs_on_ids[max_acs_id].vendor = val;
  68 +
  69 +                       p += strcspn(p, ":");
  70 +                       if (*p != ':') {
  71 +                               pr_warn("PCIe ACS invalid ID\n");
  72 +                               goto next;
  73 +                       }
  74 +
  75 +                       p++;
  76 +                       snprintf(opt, 5, "%s", p);
  77 +                       ret = kstrtol(opt, 16, &val);
  78 +                       if (ret) {
  79 +                               pr_warn("PCIe ACS ID parse error %d\n", ret);
  80 +                               goto next;
  81 +                       }
  82 +                       acs_on_ids[max_acs_id].device = val;
  83 +                       max_acs_id++;
  84 +               }
  85 +next:
  86 +               p += strcspn(p, ",");
  87 +               if (*p == ',')
  88 +                       p++;
  89 +       }
  90 +
  91 +       if (acs_on_downstream || acs_on_multifunction || max_acs_id)
  92 +               pr_warn("Warning: PCIe ACS overrides enabled; This may allow non-IOMMU protected peer-to-peer DMA\n");
  93 +
  94 +       return 0;
  95 +}
  96 +early_param("pcie_acs_override", pcie_acs_override_setup);
  97 +
  98 +static int pcie_acs_overrides(struct pci_dev *dev, u16 acs_flags)
  99 +{
 100 +       int i;
 101 +
 102 +       /* Never override ACS for legacy devices or devices with ACS caps */
 103 +       if (!pci_is_pcie(dev) ||
 104 +           pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS))
 105 +               return -ENOTTY;
 106 +
 107 +       for (i = 0; i < max_acs_id; i++)
 108 +               if (acs_on_ids[i].vendor == dev->vendor &&
 109 +                   acs_on_ids[i].device == dev->device)
 110 +                       return 1;
 111 +
 112 +       switch (pci_pcie_type(dev)) {
 113 +       case PCI_EXP_TYPE_DOWNSTREAM:
 114 +       case PCI_EXP_TYPE_ROOT_PORT:
 115 +               if (acs_on_downstream)
 116 +                       return 1;
 117 +               break;
 118 +       case PCI_EXP_TYPE_ENDPOINT:
 119 +       case PCI_EXP_TYPE_UPSTREAM:
 120 +       case PCI_EXP_TYPE_LEG_END:
 121 +       case PCI_EXP_TYPE_RC_END:
 122 +               if (acs_on_multifunction && dev->multifunction)
 123 +                       return 1;
 124 +       }
 125 +
 126 +       return -ENOTTY;
 127 +}
 128 +
 129  /*
 130   * AMD has indicated that the devices below do not support peer-to-peer
 131   * in any system where they are found in the southbridge with an AMD
 132 @@ -3483,6 +3584,7 @@ static int pci_quirk_intel_pch_acs(struc
 133         return acs_flags & ~flags ? 0 : 1;
 134  }
 135
 136 +
 137  static const struct pci_dev_acs_enabled {
 138         u16 vendor;
 139         u16 device;
 140 @@ -3495,6 +3597,7 @@ static const struct pci_dev_acs_enabled
 141         { PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_quirk_intel_pch_acs },
 142         { 0x19a2, 0x710, pci_quirk_mf_endpoint_acs }, /* Emulex BE3-R */
 143         { 0x10df, 0x720, pci_quirk_mf_endpoint_acs }, /* Emulex Skyhawk-R */
 144 +       { PCI_ANY_ID, PCI_ANY_ID, pcie_acs_overrides },
 145         { 0 }
 146  };
 147