PCI: Add "pci=hpmmiosize" and "pci=hpmmioprefsize" parameters

The existing "pci=hpmemsize=nn[KMG]" kernel parameter overrides the default
size of both the non-prefetchable and the prefetchable MMIO windows for
hotplug bridges.

Add "pci=hpmmiosize=nn[KMG]" to override the default size of only the
non-prefetchable MMIO window.

Add "pci=hpmmioprefsize=nn[KMG]" to override the default size of only the
prefetchable MMIO window.

Link: https://lore.kernel.org/r/SL2P216MB0187E4D0055791957B7E2660806B0@SL2P216MB0187.KORP216.PROD.OUTLOOK.COM
Signed-off-by: Nicholas Johnson <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Mika Westerberg <[email protected]>

Author: Nicholas-Johnson-opensource

Documentation/admin-guide/kernel-parameters.txt

@@ -3492,8 +3492,15 @@
 		hpiosize=nn[KMG]	The fixed amount of bus space which is
 				reserved for hotplug bridge's IO window.
 				Default size is 256 bytes.
+		hpmmiosize=nn[KMG]	The fixed amount of bus space which is
+				reserved for hotplug bridge's MMIO window.
+				Default size is 2 megabytes.
+		hpmmioprefsize=nn[KMG]	The fixed amount of bus space which is
+				reserved for hotplug bridge's MMIO_PREF window.
+				Default size is 2 megabytes.
 		hpmemsize=nn[KMG]	The fixed amount of bus space which is
-				reserved for hotplug bridge's memory window.
+				reserved for hotplug bridge's MMIO and
+				MMIO_PREF window.
 				Default size is 2 megabytes.
 		hpbussize=nn	The minimum amount of additional bus numbers
 				reserved for buses below a hotplug bridge.

drivers/pci/pci.c

@@ -85,10 +85,17 @@ 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)
-/* pci=hpmemsize=nnM,hpiosize=nn can override this */
+#define DEFAULT_HOTPLUG_MMIO_SIZE	(2*1024*1024)
+#define DEFAULT_HOTPLUG_MMIO_PREF_SIZE	(2*1024*1024)
+/* 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;
+/*
+ * pci=hpmmiosize=nnM overrides non-prefetchable MMIO size,
+ * pci=hpmmioprefsize=nnM overrides prefetchable MMIO size;
+ * pci=hpmemsize=nnM overrides both
+ */
+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;
@@ -6289,8 +6296,13 @@ static int __init pci_setup(char *str)
 				pcie_ecrc_get_policy(str + 5);
 			} else if (!strncmp(str, "hpiosize=", 9)) {
 				pci_hotplug_io_size = memparse(str + 9, &str);
+			} else if (!strncmp(str, "hpmmiosize=", 11)) {
+				pci_hotplug_mmio_size = memparse(str + 11, &str);
+			} else if (!strncmp(str, "hpmmioprefsize=", 15)) {
+				pci_hotplug_mmio_pref_size = memparse(str + 15, &str);
 			} else if (!strncmp(str, "hpmemsize=", 10)) {
-				pci_hotplug_mem_size = memparse(str + 10, &str);
+				pci_hotplug_mmio_size = memparse(str + 10, &str);
+				pci_hotplug_mmio_pref_size = pci_hotplug_mmio_size;
 			} else if (!strncmp(str, "hpbussize=", 10)) {
 				pci_hotplug_bus_size =
 					simple_strtoul(str + 10, &str, 0);

drivers/pci/pci.h

@@ -218,7 +218,8 @@ extern const struct device_type pci_dev_type;
 extern const struct attribute_group *pci_bus_groups[];
 
 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;
 
 /**

drivers/pci/setup-bus.c

@@ -1178,7 +1178,8 @@ 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;
 
@@ -1212,7 +1213,8 @@ 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:
@@ -1230,9 +1232,9 @@ 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
@@ -1254,9 +1256,9 @@ 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
@@ -1265,7 +1267,7 @@ 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;
 		}
@@ -1285,8 +1287,8 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 		 * prefetchable resource in a 64-bit prefetchable 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;
 	}
 }