[PCI] Make setup-bus.c aware of cardbus bridges.

Comments from rmk:

Make setup-bus.c properly aware of cardbus bridges.  We treat the
bus behind a cardbus bridge more or less like any other bus, except
we don't explicitly descend below.  We do, however, explicitly
reserve IO and memory space as we have done in the past.  Memory
space is doubed to 32MB as a measure to allow the Mobility
cardbus-pci stuff to work.  The amount of space reserved is now
specified by a couple of #defines at the top of the file.

This allows pci_bus_assign_resources() and pci_bus_size_bridges()
to be called for both root buses as well as cardbus secondary buses.

Comments from Ivan follows:

This patch combines your(rmk) cardbus changes (formerly pci-11)
and my "arbitrary resource layout" stuff. This + current bk works
on nautilus.

Most interesting feature: this can be used on partially
allocated PCI tree. For instance, i386 PCI code has always been
absolutely helpless wrt incorrectly initialized p2p bridges.
Now it can just call pci_assign_unassigned_resources() in the
end of PCI init and it would fix following problems:
- completely uninitialized bridge windows (with base and limit 0);
- erroneously "closed" windows;
- windows overlapping with something else.

drivers/pci/setup-bus.c

@@ -36,6 +36,13 @@
 
 #define ROUND_UP(x, a)		(((x) + (a) - 1) & ~((a) - 1))
 
+/*
+ * FIXME: IO should be max 256 bytes.  However, since we may
+ * have a P2P bridge below a cardbus bridge, we need 4K.
+ */
+#define CARDBUS_IO_SIZE		(4096)
+#define CARDBUS_MEM_SIZE	(32*1024*1024)
+
 static int __devinit
 pbus_assign_resources_sorted(struct pci_bus *bus)
 {
@@ -67,12 +74,67 @@ pbus_assign_resources_sorted(struct pci_bus *bus)
 	return found_vga;
 }
 
+static void __devinit
+pci_setup_cardbus(struct pci_bus *bus)
+{
+	struct pci_dev *bridge = bus->self;
+	struct pci_bus_region region;
+
+	printk("PCI: Bus %d, cardbus bridge: %s\n",
+		bus->number, bridge->slot_name);
+
+	pcibios_resource_to_bus(bridge, &region, bus->resource[0]);
+	if (bus->resource[0]->flags & IORESOURCE_IO) {
+		/*
+		 * The IO resource is allocated a range twice as large as it
+		 * would normally need.  This allows us to set both IO regs.
+		 */
+		printk("  IO window: %08lx-%08lx\n",
+			region.start, region.end);
+		pci_write_config_dword(bridge, PCI_CB_IO_BASE_0,
+					region.start);
+		pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_0,
+					region.end);
+	}
+
+	pcibios_resource_to_bus(bridge, &region, bus->resource[1]);
+	if (bus->resource[1]->flags & IORESOURCE_IO) {
+		printk("  IO window: %08lx-%08lx\n",
+			region.start, region.end);
+		pci_write_config_dword(bridge, PCI_CB_IO_BASE_1,
+					region.start);
+		pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_1,
+					region.end);
+	}
+
+	pcibios_resource_to_bus(bridge, &region, bus->resource[2]);
+	if (bus->resource[2]->flags & IORESOURCE_MEM) {
+		printk("  PREFETCH window: %08lx-%08lx\n",
+			region.start, region.end);
+		pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_0,
+					region.start);
+		pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_0,
+					region.end);
+	}
+
+	pcibios_resource_to_bus(bridge, &region, bus->resource[3]);
+	if (bus->resource[3]->flags & IORESOURCE_MEM) {
+		printk("  MEM window: %08lx-%08lx\n",
+			region.start, region.end);
+		pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_1,
+					region.start);
+		pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_1,
+					region.end);
+	}
+}
+
 /* Initialize bridges with base/limit values we have collected.
    PCI-to-PCI Bridge Architecture Specification rev. 1.1 (1998)
    requires that if there is no I/O ports or memory behind the
    bridge, corresponding range must be turned off by writing base
    value greater than limit to the bridge's base/limit registers.  */
-static void __devinit pci_setup_bridge(struct pci_bus *bus)
+static void __devinit
+pci_setup_bridge(struct pci_bus *bus)
 {
 	struct pci_dev *bridge = bus->self;
 	struct pci_bus_region region;
@@ -154,9 +216,6 @@ pci_bridge_check_ranges(struct pci_bus *bus)
 	struct pci_dev *bridge = bus->self;
 	struct resource *b_res;
 
-	if (!bridge || (bridge->class >> 8) != PCI_CLASS_BRIDGE_PCI)
-		return;
-
 	b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
 	b_res[1].flags |= IORESOURCE_MEM;
 
@@ -184,6 +243,26 @@ pci_bridge_check_ranges(struct pci_bus *bus)
 		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
 }
 
+/* Helper function for sizing routines: find first available
+   bus resource of a given type. Note: we intentionally skip
+   the bus resources which have already been assigned (that is,
+   have non-NULL parent resource). */
+static struct resource * __devinit
+find_free_bus_resource(struct pci_bus *bus, unsigned long type)
+{
+	int i;
+	struct resource *r;
+	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
+				  IORESOURCE_PREFETCH;
+
+	for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
+		r = bus->resource[i];
+		if (r && (r->flags & type_mask) == type && !r->parent)
+			return r;
+	}
+	return NULL;
+}
+
 /* Sizing the IO windows of the PCI-PCI bridge is trivial,
    since these windows have 4K granularity and the IO ranges
    of non-bridge PCI devices are limited to 256 bytes.
@@ -192,10 +271,10 @@ static void __devinit
 pbus_size_io(struct pci_bus *bus)
 {
 	struct pci_dev *dev;
-	struct resource *b_res = bus->resource[0];
+	struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
 	unsigned long size = 0, size1 = 0;
 
-	if (!(b_res->flags & IORESOURCE_IO))
+	if (!b_res)
  		return;
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
@@ -215,9 +294,6 @@ pbus_size_io(struct pci_bus *bus)
 			else
 				size1 += r_size;
 		}
-		/* ??? Reserve some resources for CardBus. */
-		if ((dev->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS)
-			size1 += 4*1024;
 	}
 /* To be fixed in 2.5: we should have sort of HAVE_ISA
    flag in the struct pci_bus. */
@@ -236,15 +312,17 @@ pbus_size_io(struct pci_bus *bus)
 
 /* Calculate the size of the bus and minimal alignment which
    guarantees that all child resources fit in this size. */
-static void __devinit
+static int __devinit
 pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long type)
 {
 	struct pci_dev *dev;
 	unsigned long min_align, align, size;
 	unsigned long aligns[12];	/* Alignments from 1Mb to 2Gb */
 	int order, max_order;
-	struct resource *b_res = (type & IORESOURCE_PREFETCH) ?
-				 bus->resource[2] : bus->resource[1];
+	struct resource *b_res = find_free_bus_resource(bus, type);
+
+	if (!b_res)
+		return 0;
 
 	memset(aligns, 0, sizeof(aligns));
 	max_order = 0;
@@ -280,11 +358,6 @@ pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long type)
 			if (order > max_order)
 				max_order = order;
 		}
-		/* ??? Reserve some resources for CardBus. */
-		if ((dev->class >> 8) == PCI_CLASS_BRIDGE_CARDBUS) {
-			size += 1UL << 24;		/* 16 Mb */
-			aligns[24 - 20] += 1UL << 24;
-		}
 	}
 
 	align = 0;
@@ -301,38 +374,111 @@ pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long type)
 	size = ROUND_UP(size, min_align);
 	if (!size) {
 		b_res->flags = 0;
-		return;
+		return 1;
 	}
 	b_res->start = min_align;
 	b_res->end = size + min_align - 1;
+	return 1;
+}
+
+static void __devinit
+pci_bus_size_cardbus(struct pci_bus *bus)
+{
+	struct pci_dev *bridge = bus->self;
+	struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
+	u16 ctrl;
+
+	/*
+	 * Reserve some resources for CardBus.  We reserve
+	 * a fixed amount of bus space for CardBus bridges.
+	 */
+	b_res[0].start = CARDBUS_IO_SIZE;
+	b_res[0].end = b_res[0].start + CARDBUS_IO_SIZE - 1;
+	b_res[0].flags |= IORESOURCE_IO;
+
+	b_res[1].start = CARDBUS_IO_SIZE;
+	b_res[1].end = b_res[1].start + CARDBUS_IO_SIZE - 1;
+	b_res[1].flags |= IORESOURCE_IO;
+
+	/*
+	 * Check whether prefetchable memory is supported
+	 * by this bridge.
+	 */
+	pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
+	if (!(ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0)) {
+		ctrl |= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
+		pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
+		pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
+	}
+
+	/*
+	 * If we have prefetchable memory support, allocate
+	 * two regions.  Otherwise, allocate one region of
+	 * twice the size.
+	 */
+	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
+		b_res[2].start = CARDBUS_MEM_SIZE;
+		b_res[2].end = b_res[2].start + CARDBUS_MEM_SIZE - 1;
+		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
+
+		b_res[3].start = CARDBUS_MEM_SIZE;
+		b_res[3].end = b_res[3].start + CARDBUS_MEM_SIZE - 1;
+		b_res[3].flags |= IORESOURCE_MEM;
+	} else {
+		b_res[3].start = CARDBUS_MEM_SIZE * 2;
+		b_res[3].end = b_res[3].start + CARDBUS_MEM_SIZE * 2 - 1;
+		b_res[3].flags |= IORESOURCE_MEM;
+	}
 }
 
 void __devinit
 pci_bus_size_bridges(struct pci_bus *bus)
 {
-	struct pci_bus *b;
-	unsigned long mask, type;
+	struct pci_dev *dev;
+	unsigned long mask, prefmask;
 
-	list_for_each_entry(b, &bus->children, node) {
+	list_for_each_entry(dev, &bus->devices, bus_list) {
+		struct pci_bus *b = dev->subordinate;
+		if (!b)
+			continue;
+
+		switch (dev->class >> 8) {
+		case PCI_CLASS_BRIDGE_CARDBUS:
+			pci_bus_size_cardbus(b);
+			break;
+
+		case PCI_CLASS_BRIDGE_PCI:
+		default:
 			pci_bus_size_bridges(b);
+			break;
+		}
 	}
 
 	/* The root bus? */
 	if (!bus->self)
 		return;
 
-	pci_bridge_check_ranges(bus);
+	switch (bus->self->class >> 8) {
+	case PCI_CLASS_BRIDGE_CARDBUS:
+		/* don't size cardbuses yet. */
+		break;
 
+	case PCI_CLASS_BRIDGE_PCI:
+		pci_bridge_check_ranges(bus);
+	default:
 		pbus_size_io(bus);
-
-	mask = type = IORESOURCE_MEM;
-	/* If the bridge supports prefetchable range, size it separately. */
-	if (bus->resource[2] &&
-	    bus->resource[2]->flags & IORESOURCE_PREFETCH) {
-		pbus_size_mem(bus, IORESOURCE_PREFETCH, IORESOURCE_PREFETCH);
-		mask |= IORESOURCE_PREFETCH;	/* Size non-prefetch only. */
+		/* If the bridge supports prefetchable range, size it
+		   separately. If it doesn't, or its prefetchable window
+		   has already been allocated by arch code, try
+		   non-prefetchable range for both types of PCI memory
+		   resources. */
+		mask = IORESOURCE_MEM;
+		prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;
+		if (pbus_size_mem(bus, prefmask, prefmask))
+			mask = prefmask; /* Success, size non-prefetch only. */
+		pbus_size_mem(bus, mask, IORESOURCE_MEM);
+		break;
 	}
-	pbus_size_mem(bus, mask, type);
 }
 EXPORT_SYMBOL(pci_bus_size_bridges);
 
@@ -351,9 +497,24 @@ pci_bus_assign_resources(struct pci_bus *bus)
 	}
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		b = dev->subordinate;
-		if (b) {
+		if (!b)
+			continue;
+
 		pci_bus_assign_resources(b);
+
+		switch (dev->class >> 8) {
+		case PCI_CLASS_BRIDGE_PCI:
 			pci_setup_bridge(b);
+			break;
+
+		case PCI_CLASS_BRIDGE_CARDBUS:
+			pci_setup_cardbus(b);
+			break;
+
+		default:
+			printk(KERN_INFO "PCI: not setting up bridge %s "
+			       "for bus %d\n", dev->slot_name, b->number);
+			break;
 		}
 	}
 }