iommu/amd: Fix unity mapping initialization race

[cascardo/linux.git] / drivers / iommu / amd_iommu_init.c

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 9e00341..59741ea 100644 (file)
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1107,13 +1107,13 @@ static int __init init_iommu_from_acpi(struct amd_iommu *iommu,
                                break;
                        }
 
+                       devid = e->devid;
                        DUMP_printk("  DEV_ACPI_HID(%s[%s])\t\tdevid: %02x:%02x.%x\n",
                                    hid, uid,
                                    PCI_BUS_NUM(devid),
                                    PCI_SLOT(devid),
                                    PCI_FUNC(devid));
 
-                       devid  = e->devid;
                        flags = e->flags;
 
                        ret = add_acpi_hid_device(hid, uid, &devid, false);
@@ -1568,13 +1568,23 @@ static int __init amd_iommu_init_pci(void)
                        break;
        }
 
+       /*
+        * Order is important here to make sure any unity map requirements are
+        * fulfilled. The unity mappings are created and written to the device
+        * table during the amd_iommu_init_api() call.
+        *
+        * After that we call init_device_table_dma() to make sure any
+        * uninitialized DTE will block DMA, and in the end we flush the caches
+        * of all IOMMUs to make sure the changes to the device table are
+        * active.
+        */
+       ret = amd_iommu_init_api();
+
        init_device_table_dma();
 
        for_each_iommu(iommu)
                iommu_flush_all_caches(iommu);
 
-       ret = amd_iommu_init_api();
-
        if (!ret)
                print_iommu_info();