diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 2b8ee90bb..400407c27 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3361,7 +3361,12 @@
 				reserved for hotplug bridge's IO window.
 				Default size is 256 bytes.
 		hpmemsize=nn[KMG]	The fixed amount of bus space which is
-				reserved for hotplug bridge's memory window.
+				reserved for hotplug bridge's MMIO window. If
+				hpmemprefsize is not specified, then the same
+				size is applied to hotplug bridge's MMIO_PREF
+				window. Default size is 2 megabytes.
+		hpmemprefsize=nn[KMG]	The fixed amount of bus space which is
+				reserved for hotplug bridge's MMIO_PREF window.
 				Default size is 2 megabytes.
 		hpbussize=nn	The minimum amount of additional bus numbers
 				reserved for buses below a hotplug bridge.
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 7c1b362f5..7c7b95aab 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -85,10 +85,12 @@ unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE;
 unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
 
 #define DEFAULT_HOTPLUG_IO_SIZE		(256)
-#define DEFAULT_HOTPLUG_MEM_SIZE	(2*1024*1024)
+#define DEFAULT_HOTPLUG_MMIO_SIZE	(2*1024*1024)
+#define DEFAULT_HOTPLUG_MMIO_PREF_SIZE	(2*1024*1024)
 /* pci=hpmemsize=nnM,hpiosize=nn can override this */
 unsigned long pci_hotplug_io_size  = DEFAULT_HOTPLUG_IO_SIZE;
-unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
+unsigned long pci_hotplug_mmio_size = DEFAULT_HOTPLUG_MMIO_SIZE;
+unsigned long pci_hotplug_mmio_pref_size = DEFAULT_HOTPLUG_MMIO_PREF_SIZE;
 
 #define DEFAULT_HOTPLUG_BUS_SIZE	1
 unsigned long pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE;
@@ -6211,6 +6213,8 @@ EXPORT_SYMBOL(pci_fixup_cardbus);
 
 static int __init pci_setup(char *str)
 {
+	bool mmio_pref_specified = false;
+
 	while (str) {
 		char *k = strchr(str, ',');
 		if (k)
@@ -6245,7 +6249,15 @@ static int __init pci_setup(char *str)
 			} else if (!strncmp(str, "hpiosize=", 9)) {
 				pci_hotplug_io_size = memparse(str + 9, &str);
 			} else if (!strncmp(str, "hpmemsize=", 10)) {
-				pci_hotplug_mem_size = memparse(str + 10, &str);
+				pci_hotplug_mmio_size =
+					memparse(str + 10, &str);
+				if (!mmio_pref_specified)
+					pci_hotplug_mmio_pref_size =
+						pci_hotplug_mmio_size;
+			} else if (!strncmp(str, "hpmemprefsize=", 14)) {
+				mmio_pref_specified = true;
+				pci_hotplug_mmio_pref_size =
+					memparse(str + 14, &str);
 			} else if (!strncmp(str, "hpbussize=", 10)) {
 				pci_hotplug_bus_size =
 					simple_strtoul(str + 10, &str, 0);
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index e7126cc0e..4386ca941 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1187,7 +1187,8 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 {
 	struct pci_dev *dev;
 	unsigned long mask, prefmask, type2 = 0, type3 = 0;
-	resource_size_t additional_mem_size = 0, additional_io_size = 0;
+	resource_size_t additional_io_size = 0, additional_mmio_size = 0,
+		additional_mmio_pref_size = 0;
 	struct resource *b_res;
 	int ret;
 
@@ -1221,7 +1222,8 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 		pci_bridge_check_ranges(bus);
 		if (bus->self->is_hotplug_bridge) {
 			additional_io_size  = pci_hotplug_io_size;
-			additional_mem_size = pci_hotplug_mem_size;
+			additional_mmio_size = pci_hotplug_mmio_size;
+			additional_mmio_pref_size = pci_hotplug_mmio_pref_size;
 		}
 		/* Fall through */
 	default:
@@ -1239,9 +1241,9 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 		if (b_res[2].flags & IORESOURCE_MEM_64) {
 			prefmask |= IORESOURCE_MEM_64;
 			ret = pbus_size_mem(bus, prefmask, prefmask,
-				  prefmask, prefmask,
-				  realloc_head ? 0 : additional_mem_size,
-				  additional_mem_size, realloc_head);
+				prefmask, prefmask,
+				realloc_head ? 0 : additional_mmio_pref_size,
+				additional_mmio_pref_size, realloc_head);
 
 			/*
 			 * If successful, all non-prefetchable resources
@@ -1263,9 +1265,9 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 		if (!type2) {
 			prefmask &= ~IORESOURCE_MEM_64;
 			ret = pbus_size_mem(bus, prefmask, prefmask,
-					 prefmask, prefmask,
-					 realloc_head ? 0 : additional_mem_size,
-					 additional_mem_size, realloc_head);
+				prefmask, prefmask,
+				realloc_head ? 0 : additional_mmio_pref_size,
+				additional_mmio_pref_size, realloc_head);
 
 			/*
 			 * If successful, only non-prefetchable resources
@@ -1274,7 +1276,8 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 			if (ret == 0)
 				mask = prefmask;
 			else
-				additional_mem_size += additional_mem_size;
+				additional_mmio_size +=
+					additional_mmio_pref_size;
 
 			type2 = type3 = IORESOURCE_MEM;
 		}
@@ -1295,8 +1298,8 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 		 * window.
 		 */
 		pbus_size_mem(bus, mask, IORESOURCE_MEM, type2, type3,
-				realloc_head ? 0 : additional_mem_size,
-				additional_mem_size, realloc_head);
+			realloc_head ? 0 : additional_mmio_size,
+			additional_mmio_size, realloc_head);
 		break;
 	}
 }
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 77448215e..7ab8f5b88 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1964,7 +1964,8 @@ extern u8 pci_dfl_cache_line_size;
 extern u8 pci_cache_line_size;
 
 extern unsigned long pci_hotplug_io_size;
-extern unsigned long pci_hotplug_mem_size;
+extern unsigned long pci_hotplug_mmio_size;
+extern unsigned long pci_hotplug_mmio_pref_size;
 extern unsigned long pci_hotplug_bus_size;
 
 /* Architecture-specific versions may override these (weak) */
