3 files changed, 13 insertions, 28 deletions
diff --git a/arch/x86/include/asm/xen/swiotlb-xen.h b/arch/x86/include/asm/xen/swiotlb-xen.h
index 77a2d19cc990..abde0f44df57 100644
--- a/arch/x86/include/asm/xen/swiotlb-xen.h
+++ b/arch/x86/include/asm/xen/swiotlb-xen.h
@@ -2,12 +2,6 @@
 #ifndef _ASM_X86_SWIOTLB_XEN_H
 #define _ASM_X86_SWIOTLB_XEN_H
 
-#ifdef CONFIG_SWIOTLB_XEN
-extern int pci_xen_swiotlb_init_late(void);
-#else
-static inline int pci_xen_swiotlb_init_late(void) { return -ENXIO; }
-#endif
-
 int xen_swiotlb_fixup(void *buf, unsigned long nslabs);
 int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
 				unsigned int address_bits,
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index de6be0a3965e..f323d83e40a7 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -72,9 +72,15 @@ static inline void __init pci_swiotlb_detect(void)
 #endif /* CONFIG_SWIOTLB */
 
 #ifdef CONFIG_SWIOTLB_XEN
+static bool xen_swiotlb_enabled(void)
+{
+	return xen_initial_domain() || x86_swiotlb_enable ||
+		(IS_ENABLED(CONFIG_XEN_PCIDEV_FRONTEND) && xen_pv_pci_possible);
+}
+
 static void __init pci_xen_swiotlb_init(void)
 {
-	if (!xen_initial_domain() && !x86_swiotlb_enable)
+	if (!xen_swiotlb_enabled())
 		return;
 	x86_swiotlb_enable = true;
 	x86_swiotlb_flags |= SWIOTLB_ANY;
@@ -83,27 +89,6 @@ static void __init pci_xen_swiotlb_init(void)
 	if (IS_ENABLED(CONFIG_PCI))
 		pci_request_acs();
 }
-
-int pci_xen_swiotlb_init_late(void)
-{
-	if (dma_ops == &xen_swiotlb_dma_ops)
-		return 0;
-
-	/* we can work with the default swiotlb */
-	if (!io_tlb_default_mem.nslabs) {
-		int rc = swiotlb_init_late(swiotlb_size_or_default(),
-					   GFP_KERNEL, xen_swiotlb_fixup);
-		if (rc < 0)
-			return rc;
-	}
-
-	/* XXX: this switches the dma ops under live devices! */
-	dma_ops = &xen_swiotlb_dma_ops;
-	if (IS_ENABLED(CONFIG_PCI))
-		pci_request_acs();
-	return 0;
-}
-EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
 #else
 static inline void __init pci_xen_swiotlb_init(void)
 {
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 50c998b844fb..b3e37961065a 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -44,6 +44,9 @@ struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
 /* Number of pages released from the initial allocation. */
 unsigned long xen_released_pages;
 
+/* Memory map would allow PCI passthrough. */
+bool xen_pv_pci_possible;
+
 /* E820 map used during setting up memory. */
 static struct e820_table xen_e820_table __initdata;
 
@@ -814,6 +817,9 @@ char * __init xen_memory_setup(void)
 		chunk_size = size;
 		type = xen_e820_table.entries[i].type;
 
+		if (type == E820_TYPE_RESERVED)
+			xen_pv_pci_possible = true;
+
 		if (type == E820_TYPE_RAM) {
 			if (addr < mem_end) {
 				chunk_size = min(size, mem_end - addr);