1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 796828fce34c..90938c7a74c1 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -3029,6 +3029,34 @@ static void __init iommu_exit_mempool(void)
 
 }
 
+static void quirk_ioat_snb_local_iommu(struct pci_dev *pdev)
+{
+        struct dmar_drhd_unit *drhd;
+        u32 vtbar;
+        int rc;
+
+        /* We know that this device on this chipset has its own IOMMU.
+         * If we find it under a different IOMMU, then the BIOS is lying
+         * to us. Hope that the IOMMU for this device is actually
+         * disabled, and it needs no translation...
+         */
+        rc = pci_bus_read_config_dword(pdev->bus, PCI_DEVFN(0, 0), 0xb0, &vtbar);
+        if (rc) {
+                /* "can't" happen */
+                dev_info(&pdev->dev, "failed to run vt-d quirk\n");
+                return;
+        }
+        vtbar &= 0xffff0000;
+
+        /* we know that the this iommu should be at offset 0xa000 from vtbar */
+        drhd = dmar_find_matched_drhd_unit(pdev);
+        if (WARN_TAINT_ONCE(!drhd || drhd->reg_base_addr - vtbar != 0xa000,
+                            TAINT_FIRMWARE_WORKAROUND,
+                            "BIOS assigned incorrect VT-d unit for Intel(R) QuickData Technology device\n"))
+                pdev->dev.archdata.iommu = DUMMY_DEVICE_DOMAIN_INFO;
+}
+DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SNB, quirk_ioat_snb_local_iommu);
+
 static void __init init_no_remapping_devices(void)
 {
         struct dmar_drhd_unit *drhd;