mn10300: insert PCI root bus resources for the ASB2305 devel motherboard

Insert PCI root bus resources for the MN10300-based ASB2305 development
kit motherboard.  This is required because the CPU's window onto the PCI
bus address space is considerably smaller than the CPU's full address
space and non-PCI devices lie outside of the PCI window that we might want
to access.

Without this patch, the PCI root bus uses the platform-level bus
resources, and these are then confined to the PCI window, thus making
platform_device_add() reject devices outside of this window.

We also add a reservation for the PCI SRAM region.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/mn10300/unit-asb2305/pci.c

@@ -26,6 +26,29 @@ int pcibios_last_bus = -1;
 struct pci_bus *pci_root_bus;
 struct pci_ops *pci_root_ops;
 
+/*
+ * The accessible PCI window does not cover the entire CPU address space, but
+ * there are devices we want to access outside of that window, so we need to
+ * insert specific PCI bus resources instead of using the platform-level bus
+ * resources directly for the PCI root bus.
+ *
+ * These are configured and inserted by pcibios_init() and are attached to the
+ * root bus by pcibios_fixup_bus().
+ */
+static struct resource pci_ioport_resource = {
+	.name	= "PCI IO",
+	.start	= 0xbe000000,
+	.end	= 0xbe03ffff,
+	.flags	= IORESOURCE_IO,
+};
+
+static struct resource pci_iomem_resource = {
+	.name	= "PCI mem",
+	.start	= 0xb8000000,
+	.end	= 0xbbffffff,
+	.flags	= IORESOURCE_MEM,
+};
+
 /*
  * Functions for accessing PCI configuration space
  */
@@ -297,6 +320,7 @@ static int __init pci_check_direct(void)
 		printk(KERN_INFO "PCI: Using configuration ampci\n");
 		request_mem_region(0xBE040000, 256, "AMPCI bridge");
 		request_mem_region(0xBFFFFFF4, 12, "PCI ampci");
+		request_mem_region(0xBC000000, 32 * 1024 * 1024, "PCI SRAM");
 		return 0;
 	}
 
@@ -358,6 +382,11 @@ void __devinit pcibios_fixup_bus(struct pci_bus *bus)
 {
 	struct pci_dev *dev;
 
+	if (bus->number == 0) {
+		bus->resource[0] = &pci_ioport_resource;
+		bus->resource[1] = &pci_iomem_resource;
+	}
+
 	if (bus->self) {
 		pci_read_bridge_bases(bus);
 		pcibios_fixup_device_resources(bus->self);
@@ -380,6 +409,11 @@ static int __init pcibios_init(void)
 	iomem_resource.start	= 0xA0000000;
 	iomem_resource.end	= 0xDFFFFFFF;
 
+	if (insert_resource(&iomem_resource, &pci_iomem_resource) < 0)
+		panic("Unable to insert PCI IOMEM resource\n");
+	if (insert_resource(&ioport_resource, &pci_ioport_resource) < 0)
+		panic("Unable to insert PCI IOPORT resource\n");
+
 	if (!pci_probe)
 		return 0;
 
@@ -391,32 +425,11 @@ static int __init pcibios_init(void)
 	printk(KERN_INFO "PCI: Probing PCI hardware [mempage %08x]\n",
 	       MEM_PAGING_REG);
 
-	{
-#if 0
-		static struct pci_bus am33_root_bus = {
-			.children  = LIST_HEAD_INIT(am33_root_bus.children),
-			.devices   = LIST_HEAD_INIT(am33_root_bus.devices),
-			.number    = 0,
-			.secondary = 0,
-			.resource = { &ioport_resource, &iomem_resource },
-		};
-
-		am33_root_bus.ops = pci_root_ops;
-		list_add_tail(&am33_root_bus.node, &pci_root_buses);
-
-		am33_root_bus.subordinate = pci_do_scan_bus(0);
-
-		pci_root_bus = &am33_root_bus;
-#else
-		pci_root_bus = pci_scan_bus(0, &pci_direct_ampci, NULL);
-#endif
-	}
+	pci_root_bus = pci_scan_bus(0, &pci_direct_ampci, NULL);
 
 	pcibios_irq_init();
 	pcibios_fixup_irqs();
-#if 0
 	pcibios_resource_survey();
-#endif
 	return 0;
 }