2 files changed, 24 insertions, 2 deletions

diff --git a/arch/x86/include/asm/xen/swiotlb-xen.h b/arch/x86/include/asm/xen/swiotlb-xen.h
index 1be1ab7d6a41..ee52fcac6f72 100644
--- a/arch/x86/include/asm/xen/swiotlb-xen.h
+++ b/arch/x86/include/asm/xen/swiotlb-xen.h
@@ -5,10 +5,12 @@
 extern int xen_swiotlb;
 extern int __init pci_xen_swiotlb_detect(void);
 extern void __init pci_xen_swiotlb_init(void);
+extern int pci_xen_swiotlb_init_late(void);
 #else
 #define xen_swiotlb (0)
 static inline int __init pci_xen_swiotlb_detect(void) { return 0; }
 static inline void __init pci_xen_swiotlb_init(void) { }
+static inline int pci_xen_swiotlb_init_late(void) { return -ENXIO; }
 #endif
 
 #endif /* _ASM_X86_SWIOTLB_XEN_H */
diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
index 1c1722761eec..b152640d8388 100644
--- a/arch/x86/xen/pci-swiotlb-xen.c
+++ b/arch/x86/xen/pci-swiotlb-xen.c
@@ -12,7 +12,7 @@
 #include <asm/iommu.h>
 #include <asm/dma.h>
 #endif
-
+#include <linux/export.h>
 int xen_swiotlb __read_mostly;
 
 static struct dma_map_ops xen_swiotlb_dma_ops = {
@@ -69,13 +69,33 @@ int __init pci_xen_swiotlb_detect(void)
 void __init pci_xen_swiotlb_init(void)
 {
         if (xen_swiotlb) {
-                xen_swiotlb_init(1);
+                xen_swiotlb_init(1, true /* early */);
                 dma_ops = &xen_swiotlb_dma_ops;
 
                 /* Make sure ACS will be enabled */
                 pci_request_acs();
         }
 }
+
+int pci_xen_swiotlb_init_late(void)
+{
+        int rc;
+
+        if (xen_swiotlb)
+                return 0;
+
+        rc = xen_swiotlb_init(1, false /* late */);
+        if (rc)
+                return rc;
+
+        dma_ops = &xen_swiotlb_dma_ops;
+        /* Make sure ACS will be enabled */
+        pci_request_acs();
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
+
 IOMMU_INIT_FINISH(pci_xen_swiotlb_detect,
                   0,
                   pci_xen_swiotlb_init,