x86/amd-iommu: attach devices to pre-allocated domains early

commit be831297 upstream.

For some devices the ACPI table may define unity map
requirements which must me met when the IOMMU is enabled. So
we need to attach devices to their domains as early as
possible so that these mappings are in place when needed.
This patch assigns the domains right after they are
allocated. Otherwise this can result in I/O page faults
before a driver binds to a device and BIOS is still using
it.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

arch/x86/kernel/amd_iommu.c

@@ -2047,10 +2047,10 @@ static void prealloc_protection_domains(void)
 	struct pci_dev *dev = NULL;
 	struct dma_ops_domain *dma_dom;
 	struct amd_iommu *iommu;
-	u16 devid;
+	u16 devid, __devid;
 
 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
-		devid = calc_devid(dev->bus->number, dev->devfn);
+		__devid = devid = calc_devid(dev->bus->number, dev->devfn);
 		if (devid > amd_iommu_last_bdf)
 			continue;
 		devid = amd_iommu_alias_table[devid];
@@ -2065,6 +2065,10 @@ static void prealloc_protection_domains(void)
 		init_unity_mappings_for_device(dma_dom, devid);
 		dma_dom->target_dev = devid;
 
+		attach_device(iommu, &dma_dom->domain, devid);
+		if (__devid != devid)
+			attach_device(iommu, &dma_dom->domain, __devid);
+
 		list_add_tail(&dma_dom->list, &iommu_pd_list);
 	}
 }