sys-kernel/gentoo-sources: acs_override patch

Signed-off-by: Xian Wang <dev@xianwang.io>

1 files changed, 124 insertions, 0 deletions

diff --git a/sys-kernel/gentoo-sources/override_for_missing_acs_capabilities.patch b/sys-kernel/gentoo-sources/override_for_missing_acs_capabilities.patch
new file mode 100644
index 0000000..00f864e
--- /dev/null
+++ b/sys-kernel/gentoo-sources/override_for_missing_acs_capabilities.patch
@@ -0,0 +1,124 @@
+--- a/drivers/pci/quirks.c	2020-05-12 20:48:40.153152132 +0300
++++ b/drivers/pci/quirks.c	2020-05-13 15:59:18.477619314 +0300
+@@ -4695,6 +4695,111 @@
+ 		PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
+ }
+ 
++/*
++* PCIe ACS Override
++*/
++static bool acs_on_downstream;
++static bool acs_on_multifunction;
++
++#define NUM_ACS_IDS 16
++struct acs_on_id {
++	unsigned short vendor;
++	unsigned short device;
++};
++static struct acs_on_id acs_on_ids[NUM_ACS_IDS];
++static u8 max_acs_id;
++
++static __init int pcie_acs_override_setup(char *p)
++{
++       if (!p)
++               return -EINVAL;
++
++       while (*p) {
++               if (!strncmp(p, "downstream", 10))
++                       acs_on_downstream = true;
++               if (!strncmp(p, "multifunction", 13))
++                       acs_on_multifunction = true;
++               if (!strncmp(p, "id:", 3)) {
++                       char opt[5];
++                       int ret;
++                       long val;
++
++                       if (max_acs_id >= NUM_ACS_IDS - 1) {
++                               pr_warn("Out of PCIe ACS override slots (%d)\n",
++                                       NUM_ACS_IDS);
++                               goto next;
++                       }
++
++                       p += 3;
++                       snprintf(opt, 5, "%s", p);
++                       ret = kstrtol(opt, 16, &val);
++                       if (ret) {
++                               pr_warn("PCIe ACS ID parse error %d\n", ret);
++                               goto next;
++                       }
++                       acs_on_ids[max_acs_id].vendor = val;
++
++                       p += strcspn(p, ":");
++                       if (*p != ':') {
++                               pr_warn("PCIe ACS invalid ID\n");
++                               goto next;
++                       }
++
++                       p++;
++                       snprintf(opt, 5, "%s", p);
++                       ret = kstrtol(opt, 16, &val);
++                       if (ret) {
++                               pr_warn("PCIe ACS ID parse error %d\n", ret);
++                               goto next;
++                       }
++                       acs_on_ids[max_acs_id].device = val;
++                       max_acs_id++;
++               }
++next:
++               p += strcspn(p, ",");
++               if (*p == ',')
++                       p++;
++       }
++
++       if (acs_on_downstream || acs_on_multifunction || max_acs_id)
++               pr_warn("Warning: PCIe ACS overrides enabled; This may allow non-IOMMU protected peer-to-peer DMA\n");
++
++       return 0;
++}
++
++early_param("pcie_acs_override", pcie_acs_override_setup);
++
++static int pcie_acs_overrides(struct pci_dev *dev, u16 acs_flags)
++{
++       int i;
++
++       /* Never override ACS for legacy devices or devices with ACS caps */
++       if (!pci_is_pcie(dev) ||
++           pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS))
++               return -ENOTTY;
++
++       for (i = 0; i < max_acs_id; i++)
++               if (acs_on_ids[i].vendor == dev->vendor &&
++                   acs_on_ids[i].device == dev->device)
++                       return 1;
++
++       switch (pci_pcie_type(dev)) {
++       case PCI_EXP_TYPE_DOWNSTREAM:
++       case PCI_EXP_TYPE_ROOT_PORT:
++               if (acs_on_downstream)
++                       return 1;
++               break;
++       case PCI_EXP_TYPE_ENDPOINT:
++       case PCI_EXP_TYPE_UPSTREAM:
++       case PCI_EXP_TYPE_LEG_END:
++       case PCI_EXP_TYPE_RC_END:
++               if (acs_on_multifunction && dev->multifunction)
++                       return 1;
++       }
++
++       return -ENOTTY;
++}
++
+ static const struct pci_dev_acs_enabled {
+ 	u16 vendor;
+ 	u16 device;
+@@ -5001,6 +5001,8 @@
+ 	/* Zhaoxin Root/Downstream Ports */
+ 	{ PCI_VENDOR_ID_ZHAOXIN, PCI_ANY_ID, pci_quirk_zhaoxin_pcie_ports_acs },
+	/* Wangxun nics */
+	{ PCI_VENDOR_ID_WANGXUN, PCI_ANY_ID, pci_quirk_wangxun_nic_acs },
++	/* IOMMU ACS override patch */
++	{ PCI_ANY_ID, PCI_ANY_ID, pcie_acs_overrides },
+ 	{ 0 }
+ };
+