- Initial checkin of the freebios2 tree

git-svn-id: svn://svn.coreboot.org/coreboot/trunk@784 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

1 files changed, 670 insertions, 0 deletions

diff --git a/src/devices/pci_device.c b/src/devices/pci_device.c
new file mode 100644
index 0000000000..2b309a9ae1
--- /dev/null
+++ b/src/devices/pci_device.c
@@ -0,0 +1,670 @@
+/*
+ *      PCI Bus Services, see include/linux/pci.h for further explanation.
+ *
+ *      Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
+ *      David Mosberger-Tang
+ *
+ *      Copyright 1997 -- 1999 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
+ *	
+ *	Copyright 2003 -- Eric Biederman <ebiederman@lnxi.com>
+ */
+
+#include <console/console.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <bitops.h>
+#include <pci.h>
+#include <pci_ids.h>
+#include <string.h>
+
+static unsigned int pci_scan_bridge(struct device *bus, unsigned int max);
+
+/** Given a device and register, read the size of the BAR for that register. 
+ * @param dev       Pointer to the device structure
+ * @param resource  Pointer to the resource structure
+ * @param index     Address of the pci configuration register
+ */
+static void pci_get_resource(struct device *dev, struct resource *resource, unsigned long index)
+{
+	uint32_t addr, size, base;
+	unsigned long type;
+
+	/* Initialize the resources to nothing */
+	resource->base = 0;
+	resource->size = 0;
+	resource->align = 0;
+	resource->gran = 0;
+	resource->limit = 0;
+	resource->flags = 0;
+	resource->index = index;
+
+	pci_read_config_dword(dev, index, &addr);
+	if (addr == 0xffffffffUL)
+		return;
+
+	/* FIXME: more consideration for 64-bit PCI devices,
+	 * we currently detect their size but otherwise
+	 * treat them as 32-bit resources
+	 */
+	/* get the size */
+	pci_write_config_dword(dev, index, ~0);
+	pci_read_config_dword(dev,  index, &size);
+
+	/* get the minimum value the bar can be set to */
+	pci_write_config_dword(dev, index, 0);
+	pci_read_config_dword(dev, index, &base);
+
+	/* restore addr */
+	pci_write_config_dword(dev, index, addr);
+
+	/*
+	 * some broken hardware has read-only registers that do not 
+	 * really size correctly. You can tell this if addr == size
+	 * Example: the acer m7229 has BARs 1-4 normally read-only. 
+	 * so BAR1 at offset 0x10 reads 0x1f1. If you size that register
+	 * by writing 0xffffffff to it, it will read back as 0x1f1 -- a 
+	 * violation of the spec. 
+	 * We catch this case and ignore it by settting size and type to 0.
+	 * This incidentally catches the common case where registers 
+	 * read back as 0 for both address and size. 
+	 */
+	if ((addr == size) && (addr == base)) {
+		if (size != 0) {
+			printk_debug(
+				"PCI: %02x:%02x.%01x register %02x(%08x), read-only ignoring it\n",
+				dev->bus->secondary,
+				PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn), 
+				index, addr);
+		}
+		resource->flags = 0;
+	}
+	/* Now compute the actual size, See PCI Spec 6.2.5.1 ...  */
+	else if (size & PCI_BASE_ADDRESS_SPACE_IO) {
+		type = size & (~PCI_BASE_ADDRESS_IO_MASK);
+		/* BUG! Top 16 bits can be zero (or not) 
+		 * So set them to 0xffff so they go away ...
+		 */
+		resource->size = (~((size | 0xffff0000) & PCI_BASE_ADDRESS_IO_MASK)) +1;
+		resource->align = log2(resource->size);
+		resource->gran = resource->align;
+		resource->flags = IORESOURCE_IO;
+		resource->limit = 0xffff;
+	} 
+	else {
+		/* A Memory mapped base address */
+		type = size & (~PCI_BASE_ADDRESS_MEM_MASK);
+		resource->size = (~(size &PCI_BASE_ADDRESS_MEM_MASK)) +1;
+		resource->align = log2(resource->size);
+		resource->gran = resource->align;
+		resource->flags = IORESOURCE_MEM;
+		if (type & PCI_BASE_ADDRESS_MEM_PREFETCH) {
+			resource->flags |= IORESOURCE_PREFETCH;
+		}
+		type &= PCI_BASE_ADDRESS_MEM_TYPE_MASK;
+		if (type == PCI_BASE_ADDRESS_MEM_TYPE_32) {
+			/* 32bit limit */
+			resource->limit = 0xffffffffUL;
+		}
+		else if (type == PCI_BASE_ADDRESS_MEM_TYPE_1M) {
+			/* 1MB limit */
+			resource->limit = 0x000fffffUL;
+		}
+		else if (type == PCI_BASE_ADDRESS_MEM_TYPE_64) {
+			unsigned long index_hi;
+			/* 64bit limit 
+			 * For now just treat this as a 32bit limit
+			 */
+			index_hi = index + 4;
+			resource->limit = 0xffffffffUL;
+			resource->flags |= IORESOURCE_PCI64;
+			pci_read_config_dword( dev, index_hi, &addr);
+			/* get the extended size */
+			pci_write_config_dword(dev, index_hi, 0xffffffffUL);
+			pci_read_config_dword( dev, index_hi, &size);
+
+			/* get the minimum value the bar can be set to */
+			pci_write_config_dword(dev, index_hi, 0);
+			pci_read_config_dword(dev,  index_hi, &base);
+
+			/* restore addr */
+			pci_write_config_dword(dev, index_hi, addr);
+			
+			if ((size == 0xffffffff) && (base == 0)) {
+				/* Clear the top half of the bar */
+				pci_write_config_dword(dev, index_hi, 0);
+			}
+			else {
+				printk_err("PCI: %02x:%02x.%01x Unable to handle 64-bit address\n",
+					dev->bus->secondary, 
+					PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
+				resource->flags = IORESOURCE_PCI64;
+			}
+		} 
+		else {
+			/* Invalid value */
+			resource->flags = 0;
+		}
+	}
+	/* dev->size holds the flags... */
+	return;
+}
+
+/** Read the base address registers for a given device. 
+ * @param dev Pointer to the dev structure
+ * @param howmany How many registers to read (6 for device, 2 for bridge)
+ */
+static void pci_read_bases(struct device *dev, unsigned int howmany)
+{
+	unsigned int reg;
+	unsigned long index;
+
+	reg = dev->resources;
+	for(index = PCI_BASE_ADDRESS_0; 
+	    (reg < MAX_RESOURCES) && (index < PCI_BASE_ADDRESS_0 + (howmany << 2)); ) {
+		struct resource *resource;
+		resource = &dev->resource[reg];
+		pci_get_resource(dev, resource, index);
+		reg += (resource->flags & (IORESOURCE_IO | IORESOURCE_MEM))? 1:0;
+		index += (resource->flags & IORESOURCE_PCI64)?8:4;
+	}
+	dev->resources = reg;
+}
+
+
+static void pci_bridge_read_bases(struct device *dev)
+{
+	unsigned int reg = dev->resources;
+
+	/* FIXME handle bridges without some of the optional resources */
+
+	/* Initialize the io space constraints on the current bus */
+	dev->resource[reg].base  = 0;
+	dev->resource[reg].size  = 0;
+	dev->resource[reg].align = log2(PCI_IO_BRIDGE_ALIGN);
+	dev->resource[reg].gran  = log2(PCI_IO_BRIDGE_ALIGN);
+	dev->resource[reg].limit = 0xffffUL;
+	dev->resource[reg].flags = IORESOURCE_IO | IORESOURCE_PCI_BRIDGE;
+	dev->resource[reg].index = PCI_IO_BASE;
+	compute_allocate_resource(dev, &dev->resource[reg],
+		IORESOURCE_IO, IORESOURCE_IO);
+	reg++;
+
+	/* Initiliaze the prefetchable memory constraints on the current bus */
+	dev->resource[reg].base = 0;
+	dev->resource[reg].size = 0;
+	dev->resource[reg].align = log2(PCI_MEM_BRIDGE_ALIGN);
+	dev->resource[reg].gran  = log2(PCI_MEM_BRIDGE_ALIGN);
+	dev->resource[reg].limit = 0xffffffffUL;
+	dev->resource[reg].flags = IORESOURCE_MEM | IORESOURCE_PREFETCH | IORESOURCE_PCI_BRIDGE;
+	dev->resource[reg].index = PCI_PREF_MEMORY_BASE;
+	compute_allocate_resource(dev, &dev->resource[reg],
+		IORESOURCE_MEM | IORESOURCE_PREFETCH, 
+		IORESOURCE_MEM | IORESOURCE_PREFETCH);
+	reg++;
+
+	/* Initialize the memory resources on the current bus */
+	dev->resource[reg].base = 0;
+	dev->resource[reg].size = 0;
+	dev->resource[reg].align = log2(PCI_MEM_BRIDGE_ALIGN);
+	dev->resource[reg].gran  = log2(PCI_MEM_BRIDGE_ALIGN);
+	dev->resource[reg].limit = 0xffffffffUL;
+	dev->resource[reg].flags = IORESOURCE_MEM | IORESOURCE_PCI_BRIDGE;
+	dev->resource[reg].index = PCI_MEMORY_BASE;
+	compute_allocate_resource(dev, &dev->resource[reg],
+		IORESOURCE_MEM | IORESOURCE_PREFETCH, 
+		IORESOURCE_MEM);
+	reg++;
+
+	dev->resources = reg;
+}
+
+
+static void pci_dev_read_resources(struct device *dev)
+{
+	uint32_t addr;
+	dev->resources = 0;
+	memset(&dev->resource[0], 0, sizeof(dev->resource));
+	pci_read_bases(dev, 6);
+	pci_read_config_dword(dev, PCI_ROM_ADDRESS, &addr);
+	dev->rom_address = (addr == 0xffffffff)? 0 : addr;
+}
+
+static void pci_bus_read_resources(struct device *dev)
+{
+	uint32_t addr;
+	dev->resources = 0;
+	memset(&dev->resource[0], 0, sizeof(dev->resource));
+	pci_bridge_read_bases(dev);
+	pci_read_bases(dev, 2);
+	
+	pci_read_config_dword(dev, PCI_ROM_ADDRESS1, &addr);
+	dev->rom_address = (addr == 0xffffffff)? 0 : addr;
+
+}
+
+
+static void pci_set_resource(struct device *dev, struct resource *resource)
+{
+	unsigned long base, limit;
+	unsigned long bridge_align = PCI_MEM_BRIDGE_ALIGN;
+	unsigned char buf[10];
+	
+	/* Make certain the resource has actually been set */
+	if (!(resource->flags & IORESOURCE_SET)) {
+#if 1
+		printk_err("ERROR: %02x:%02x.%01x %02x not allocated\n",
+			dev->bus->secondary,
+			PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn), 
+			resource->index);
+#endif
+		return;
+	}
+
+	/* Only handle PCI memory and IO resources for now */
+	if (!(resource->flags & (IORESOURCE_MEM |IORESOURCE_IO)))
+		return;
+	
+	if (resource->flags & IORESOURCE_MEM) {
+		dev->command |= PCI_COMMAND_MEMORY;
+		bridge_align = PCI_MEM_BRIDGE_ALIGN;
+	}
+	if (resource->flags & IORESOURCE_IO) {
+		dev->command |= PCI_COMMAND_IO;
+		bridge_align = PCI_IO_BRIDGE_ALIGN;
+	}
+	if (resource->flags & IORESOURCE_PCI_BRIDGE) {
+		dev->command |= PCI_COMMAND_MASTER;
+	}
+	/* Get the base address */
+	base = resource->base;
+	
+	/* Get the limit (rounded up) */
+	limit = base + ((resource->size + bridge_align - 1UL) & ~(bridge_align -1)) -1UL;
+	
+	if (!(resource->flags & IORESOURCE_PCI_BRIDGE)) {
+		/*
+		 * some chipsets allow us to set/clear the IO bit. 
+		 * (e.g. VIA 82c686a.) So set it to be safe)
+		 */
+		limit = base + resource->size -1;
+		if (resource->flags & IORESOURCE_IO) {
+			base |= PCI_BASE_ADDRESS_SPACE_IO;
+		}
+		pci_write_config_dword(dev, resource->index, base & 0xffffffff);
+		if (resource->flags & IORESOURCE_PCI64) {
+			/* FIXME handle real 64bit base addresses */
+			pci_write_config_dword(dev, resource->index + 4, 0);
+		}
+	}
+	else if (resource->index == PCI_IO_BASE) {
+		/* set the IO ranges
+		 * WARNING: we don't really do 32-bit addressing for IO yet! 
+		 */
+		compute_allocate_resource(dev, resource, 
+			IORESOURCE_IO, IORESOURCE_IO);
+		pci_write_config_byte(dev, PCI_IO_BASE,  base >> 8);
+		pci_write_config_byte(dev, PCI_IO_LIMIT, limit >> 8);
+	}
+	else if (resource->index == PCI_MEMORY_BASE) {
+		/* set the memory range
+		 */
+		compute_allocate_resource(dev, resource,
+			IORESOURCE_MEM | IORESOURCE_PREFETCH, 
+			IORESOURCE_MEM);
+		pci_write_config_word(dev, PCI_MEMORY_BASE, base >> 16);
+		pci_write_config_word(dev, PCI_MEMORY_LIMIT, limit >> 16);
+	}
+	else if (resource->index == PCI_PREF_MEMORY_BASE) {
+		/* set the prefetchable memory range
+		 * WARNING: we don't really do 64-bit addressing for prefetchable memory yet!
+		 */
+		compute_allocate_resource(dev, resource,
+			IORESOURCE_MEM | IORESOURCE_PREFETCH, 
+			IORESOURCE_MEM | IORESOURCE_PREFETCH);
+		pci_write_config_word(dev, PCI_PREF_MEMORY_BASE,  base >> 16);
+		pci_write_config_word(dev, PCI_PREF_MEMORY_LIMIT, limit >> 16);
+	}
+	else {
+		printk_err("ERROR: invalid resource->index %x\n",
+			resource->index);
+	}
+	buf[0] = '\0';
+	if (resource->flags & IORESOURCE_PCI_BRIDGE) {
+		sprintf(buf, "bus %d ", dev->secondary);
+	}
+	
+	printk_debug(
+		"PCI: %02x:%02x.%01x %02x <- [0x%08lx - 0x%08lx] %s%s\n",
+		dev->bus->secondary, 
+		PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn), 
+		resource->index, 
+		resource->base, limit,
+		buf,
+		(resource->flags & IORESOURCE_IO)? "io":
+		(resource->flags & IORESOURCE_PREFETCH)? "prefmem": "mem");
+	return;
+}
+
+static void pci_dev_set_resources(struct device *dev)
+{
+	struct resource *resource, *last;
+	uint8_t line;
+
+	last = &dev->resource[dev->resources];
+
+	for(resource = &dev->resource[0]; resource < last; resource++) {
+		pci_set_resource(dev, resource);
+	}
+	if (dev->children) {
+		assign_resources(dev);
+	}
+
+	/* set a default latency timer */
+	pci_write_config_byte(dev, PCI_LATENCY_TIMER, 0x40);
+
+	/* set a default secondary latency timer */
+	if ((dev->hdr_type & 0x7f) == PCI_HEADER_TYPE_BRIDGE) {
+		pci_write_config_byte(dev, PCI_SEC_LATENCY_TIMER, 0x40);
+	}
+
+	/* zero the irq settings */
+	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &line);
+	if (line) {
+		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, 0);
+	}
+	/* set the cache line size, so far 64 bytes is good for everyone */
+	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, 64 >> 2);
+}
+
+struct device_operations default_pci_ops_dev = {
+	.read_resources = pci_dev_read_resources,
+	.set_resources = pci_dev_set_resources,
+	.init = 0,
+	.scan_bus = 0,
+};
+struct device_operations default_pci_ops_bus = {
+	.read_resources = pci_bus_read_resources,
+	.set_resources = pci_dev_set_resources,
+	.init = 0,
+	.scan_bus = pci_scan_bridge,
+};
+static void set_pci_ops(struct device *dev)
+{
+	struct pci_driver *driver;
+	if (dev->ops) {
+		return;
+	}
+	/* Look through the list of setup drivers and find one for
+	 * this pci device 
+	 */
+	for(driver = &pci_drivers[0]; driver != &epci_drivers[0]; driver++) {
+		if ((driver->vendor == dev->vendor) &&
+			(driver->device = dev->device)) {
+			dev->ops = driver->ops;
+			break;
+		}
+	}
+	/* If I don't have a specific driver use the default operations */
+	switch(dev->hdr_type & 0x7f) {	/* header type */
+	case PCI_HEADER_TYPE_NORMAL:	/* standard header */
+		if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI)
+			goto bad;
+		dev->ops = &default_pci_ops_dev;
+		break;
+	case PCI_HEADER_TYPE_BRIDGE:
+		if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
+			goto bad;
+		dev->ops = &default_pci_ops_bus;
+		break;
+	default:
+	bad:
+		printk_err("PCI: %02x:%02x.%01x [%04x/%04x/%06x] has unknown header "
+			"type %02x, ignoring.\n",
+			dev->bus->secondary, 
+			PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn), 
+			dev->vendor, dev->device, 
+			dev->class >> 8, dev->hdr_type);
+	}
+	return;
+}
+
+/**
+ * Given a bus and a devfn number, find the device structure
+ * @param bus The bus structure
+ * @param devfn a device/function number
+ * @return pointer to the device structure
+ */
+static struct device *pci_scan_get_dev(struct device **list, unsigned int devfn)
+{
+	struct device *dev = 0;
+	for(; *list; list = &(*list)->sibling) {
+		if ((*list)->devfn == devfn) {
+			/* Unlink from the list */
+			dev = *list;
+			*list = (*list)->sibling;
+			dev->sibling = 0;
+			break;
+		}
+	}
+	return dev;
+}
+
+
+/** Scan the pci bus devices and bridges.
+ * @param pci_bus pointer to the bus structure
+ * @param max current bus number
+ * @return The maximum bus number found, after scanning all subordinate busses
+ */
+unsigned int pci_scan_bus(struct device *bus, unsigned int max)
+{
+	unsigned int devfn;
+	struct device *dev, **bus_last;
+	struct device *old_devices;
+	struct device *child;
+
+	printk_debug("PCI: pci_scan_bus for bus %d\n", bus->secondary);
+
+	old_devices = bus->children;
+	bus->children = 0;
+	bus_last = &bus->children;
+
+	post_code(0x24);
+	
+
+	/* probe all devices on this bus with some optimization for non-existance and 
+	   single funcion devices */
+	for (devfn = 0; devfn < 0xff; devfn++) {
+		struct device dummy;
+		uint32_t id, class;
+		uint8_t cmd, tmp, hdr_type;
+
+		/* First thing setup the device structure */
+		dev = pci_scan_get_dev(&old_devices, devfn);
+	
+		dummy.bus = bus;
+		dummy.devfn = devfn;
+		pci_read_config_dword(&dummy, PCI_VENDOR_ID, &id);
+		/* some broken boards return 0 if a slot is empty: */
+		if (!dev &&
+			(id == 0xffffffff || id == 0x00000000 || 
+			 id == 0x0000ffff || id == 0xffff0000)) {
+			printk_spew("PCI: devfn 0x%x, bad id 0x%x\n", devfn, id);
+			if (PCI_FUNC(devfn) == 0x00) {
+				/* if this is a function 0 device and it is not present,
+				   skip to next device */
+				devfn += 0x07;
+			}
+			/* multi function device, skip to next function */
+			continue;
+		}
+		pci_read_config_byte(&dummy, PCI_HEADER_TYPE, &hdr_type);
+		pci_read_config_dword(&dummy, PCI_CLASS_REVISION, &class);
+
+		if (!dev) {
+			if ((dev = malloc(sizeof(*dev))) == 0) {
+				printk_err("PCI: out of memory.\n");
+				continue;
+			}
+			memset(dev, 0, sizeof(*dev));
+		}
+
+		dev->bus = bus;
+		dev->devfn = devfn;
+		dev->vendor = id & 0xffff;
+		dev->device = (id >> 16) & 0xffff;
+		dev->hdr_type = hdr_type;
+		/* class code, the upper 3 bytes of PCI_CLASS_REVISION */
+		dev->class = class >> 8;
+
+		/* non-destructively determine if device can be a master: */
+		pci_read_config_byte(dev, PCI_COMMAND, &cmd);
+		pci_write_config_byte(dev, PCI_COMMAND, cmd | PCI_COMMAND_MASTER);
+		pci_read_config_byte(dev, PCI_COMMAND, &tmp);
+
+		dev->master = ((tmp & PCI_COMMAND_MASTER) != 0);
+		pci_write_config_byte(dev, PCI_COMMAND, cmd);
+
+		/* Look at the vendor and device id, or at least the 
+		 * header type and class and figure out which set of configuration
+		 * methods to use.
+		 */
+		set_pci_ops(dev);
+		/* Kill the device if we don't have some pci operations for it */
+		if (!dev->ops) {
+			free(dev);
+			continue;
+		}
+		printk_debug("PCI: %02x:%02x.%01x [%04x/%04x]\n", 
+			bus->secondary, PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn), 
+			dev->vendor, dev->device);
+
+		/* Put it into the global device chain. */
+		append_device(dev);
+
+		/* Now insert it into the list of devices held by the parent bus. */
+		*bus_last = dev;
+		bus_last = &dev->sibling;
+
+		if (PCI_FUNC(devfn) == 0x00 && (hdr_type & 0x80) != 0x80) {
+			/* if this is not a multi function device, don't waste time probe
+			   another function. Skip to next device. */
+			devfn += 0x07;
+		}
+	}
+	post_code(0x25);
+
+	for(child = bus->children; child; child = child->sibling) {
+		if (!child->ops->scan_bus)
+			continue;
+		max = child->ops->scan_bus(child, max);
+		
+	}
+	/*
+	 * We've scanned the bus and so we know all about what's on
+	 * the other side of any bridges that may be on this bus plus
+	 * any devices.
+	 *
+	 * Return how far we've got finding sub-buses.
+	 */
+	printk_debug("PCI: pci_scan_bus returning with max=%02x\n", max);
+	post_code(0x55);
+	return max;
+}
+
+/** Scan the bus, first for bridges and next for devices. 
+ * @param pci_bus pointer to the bus structure
+ * @return The maximum bus number found, after scanning all subordinate busses
+ */
+static unsigned int pci_scan_bridge(struct device *bus, unsigned int max)
+{
+	uint32_t buses;
+	uint16_t cr;
+	/* Set up the primary, secondary and subordinate bus numbers. We have
+	 * no idea how many buses are behind this bridge yet, so we set the
+	 * subordinate bus number to 0xff for the moment 
+	 */
+	bus->secondary = ++max;
+	bus->subordinate = 0xff;
+	
+	/* Clear all status bits and turn off memory, I/O and master enables. */
+	pci_read_config_word(bus, PCI_COMMAND, &cr);
+	pci_write_config_word(bus, PCI_COMMAND, 0x0000);
+	pci_write_config_word(bus, PCI_STATUS, 0xffff);
+
+	/*
+	 * Read the existing primary/secondary/subordinate bus
+	 * number configuration.
+	 */
+	pci_read_config_dword(bus, PCI_PRIMARY_BUS, &buses);
+
+	/* Configure the bus numbers for this bridge: the configuration
+	 * transactions will not be propagated by the bridge if it is not
+	 * correctly configured 
+	 */
+	buses &= 0xff000000;
+	buses |= (((unsigned int) (bus->bus->secondary) << 0) |
+		((unsigned int) (bus->secondary) << 8) |
+		((unsigned int) (bus->subordinate) << 16));
+	pci_write_config_dword(bus, PCI_PRIMARY_BUS, buses);
+	
+	/* Now we can scan all subordinate buses i.e. the bus hehind the bridge */
+	max = pci_scan_bus(bus, max);
+	
+	/* We know the number of buses behind this bridge. Set the subordinate
+	 *  bus number to its real value 
+	 */
+	bus->subordinate = max;
+	buses = (buses & 0xff00ffff) |
+		((unsigned int) (bus->subordinate) << 16);
+	pci_write_config_dword(bus, PCI_PRIMARY_BUS, buses);
+	pci_write_config_word(bus, PCI_COMMAND, cr);
+		
+	return max;
+}
+
+
+static void pci_root_read_resources(struct device *bus)
+{
+	int res = 0;
+	/* Initialize the system wide io space constraints */
+	bus->resource[res].base  = 0x400;
+	bus->resource[res].size  = 0;
+	bus->resource[res].align = 0;
+	bus->resource[res].gran  = 0;
+	bus->resource[res].limit = 0xffffUL;
+	bus->resource[res].flags = IORESOURCE_IO;
+	bus->resource[res].index = PCI_IO_BASE;
+	compute_allocate_resource(bus, &bus->resource[res], 
+		IORESOURCE_IO, IORESOURCE_IO);
+	res++;
+
+	/* Initialize the system wide memory resources constraints */
+	bus->resource[res].base  = 0;
+	bus->resource[res].size  = 0;
+	bus->resource[res].align = 0;
+	bus->resource[res].gran  = 0;
+	bus->resource[res].limit = 0xffffffffUL;
+	bus->resource[res].flags = IORESOURCE_MEM;
+	bus->resource[res].index = PCI_MEMORY_BASE;
+	compute_allocate_resource(bus, &bus->resource[res], 
+		IORESOURCE_MEM, IORESOURCE_MEM);
+	res++;
+
+	bus->resources = res;
+}
+static void pci_root_set_resources(struct device *bus)
+{
+	compute_allocate_resource(bus,
+		&bus->resource[0], IORESOURCE_IO, IORESOURCE_IO);
+	compute_allocate_resource(bus, 
+		&bus->resource[1], IORESOURCE_MEM, IORESOURCE_MEM);
+	assign_resources(bus);
+}
+
+struct device_operations default_pci_ops_root = {
+	.read_resources = pci_root_read_resources,
+	.set_resources = pci_root_set_resources,
+	.init = 0,
+	.scan_bus = pci_scan_bus,
+};
+