path: root/arch/ppc/kernel/pci.c

/*
 * $Id: pci.c,v 1.64 1999/09/17 18:01:53 cort Exp $
 * Common pmac/prep/chrp pci routines. -- Cort
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/capability.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/bootmem.h>

#include <asm/processor.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/residual.h>
#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/gg2.h>
#include <asm/uaccess.h>

#include "pci.h"

#define DEBUG

#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif

unsigned long isa_io_base     = 0;
unsigned long isa_mem_base    = 0;
unsigned long pci_dram_offset = 0;

static u8* pci_to_OF_bus_map;

static void pcibios_fixup_resources(struct pci_dev* dev);
#ifdef CONFIG_ALL_PPC
static void pcibios_fixup_cardbus(struct pci_dev* dev);
#endif

/* By default, we don't re-assign bus numbers. We do this only on
 * some pmacs
 */
int pci_assign_all_busses;

struct pci_controller* hose_head;
struct pci_controller** hose_tail = &hose_head;

static int pci_bus_count;

struct pci_fixup pcibios_fixups[] = {
	{ PCI_FIXUP_HEADER,	PCI_ANY_ID,		PCI_ANY_ID,		pcibios_fixup_resources },
#ifdef CONFIG_ALL_PPC
	/* We should add per-machine fixup support in xxx_setup.c or xxx_pci.c */
	{ PCI_FIXUP_FINAL,	PCI_VENDOR_ID_TI, 	PCI_DEVICE_ID_TI_1211, 	pcibios_fixup_cardbus }, 
#endif /* CONFIG_ALL_PPC */
 	{ 0 }
};

void
pcibios_update_resource(struct pci_dev *dev, struct resource *root,
			     struct resource *res, int resource)
{
	u32 new, check;
	int reg;
	struct pci_controller* hose = dev->sysdata;
	
	new = res->start;
	if (hose && res->flags & IORESOURCE_MEM)
		new -= hose->pci_mem_offset;
	new |= (res->flags & PCI_REGION_FLAG_MASK);
	if (resource < 6) {
		reg = PCI_BASE_ADDRESS_0 + 4*resource;
	} else if (resource == PCI_ROM_RESOURCE) {
		res->flags |= PCI_ROM_ADDRESS_ENABLE;
		reg = dev->rom_base_reg;
	} else {
		/* Somebody might have asked allocation of a non-standard resource */
		return;
	}

	pci_write_config_dword(dev, reg, new);
	pci_read_config_dword(dev, reg, &check);
	if ((new ^ check) & ((new & PCI_BASE_ADDRESS_SPACE_IO) ? PCI_BASE_ADDRESS_IO_MASK : PCI_BASE_ADDRESS_MEM_MASK)) {
		printk(KERN_ERR "PCI: Error while updating region "
		       "%s/%d (%08x != %08x)\n", dev->slot_name, resource,
		       new, check);
	}
}

static void
pcibios_fixup_resources(struct pci_dev* dev)
{
	struct pci_controller* hose =
		(struct pci_controller *)dev->sysdata;
	int i;
	if (!hose) {
		printk("No hose for PCI dev %x.%x !\n", dev->bus->number, dev->devfn >> 3);
		return;
	}
	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
		struct resource *res = dev->resource + i;
		if (!res->start)
			continue;
		if ((res->flags & IORESOURCE_MEM) && hose->pci_mem_offset) {
			res->start += hose->pci_mem_offset;
			res->end += hose->pci_mem_offset;
#ifdef DEBUG
			printk("Fixup mem res, dev: %x.%x, res_start: %lx->%lx\n",
			       dev->bus->number, dev->devfn>>3, res->start-hose->pci_mem_offset,
			       res->start);
#endif
		}

		if ((res->flags & IORESOURCE_IO)
		    && (unsigned long) hose->io_base_virt != isa_io_base) {
			unsigned long offs;

			offs = (unsigned long)hose->io_base_virt - isa_io_base;
			res->start += offs;
			res->end += offs;
			printk("Fixup IO res, dev: %x.%x, res_start: %lx->%lx\n",
			       dev->bus->number, dev->devfn>>3,
			       res->start - offs, res->start);
		}
	}
}

#ifdef CONFIG_ALL_PPC
static void
pcibios_fixup_cardbus(struct pci_dev* dev)
{
	/*
	 * Fix the interrupt routing on the TI1211 chip on the 1999
	 * G3 powerbook, which doesn't get initialized properly by OF.
	 */
	if (dev->vendor == PCI_VENDOR_ID_TI
	    && dev->device == PCI_DEVICE_ID_TI_1211) {
		u32 val;
		/* 0x8c == TI122X_IRQMUX, 2 says to route the INTA
		   signal out the MFUNC0 pin */
		if (pci_read_config_dword(dev, 0x8c, &val) == 0
		    && val == 0)
			pci_write_config_dword(dev, 0x8c, 2);
	}
}
#endif /* CONFIG_ALL_PPC */

/*
 * We need to avoid collisions with `mirrored' VGA ports
 * and other strange ISA hardware, so we always want the
 * addresses to be allocated in the 0x000-0x0ff region
 * modulo 0x400.
 *
 * Why? Because some silly external IO cards only decode
 * the low 10 bits of the IO address. The 0x00-0xff region
 * is reserved for motherboard devices that decode all 16
 * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
 * but we want to try to avoid allocating at 0x2900-0x2bff
 * which might have be mirrored at 0x0100-0x03ff..
 */
void
pcibios_align_resource(void *data, struct resource *res, unsigned long size)
{
	struct pci_dev *dev = data;

	if (res->flags & IORESOURCE_IO) {
		unsigned long start = res->start;

		if (size > 0x100) {
			printk(KERN_ERR "PCI: I/O Region %s/%d too large"
			       " (%ld bytes)\n", dev->slot_name,
			       dev->resource - res, size);
		}

		if (start & 0x300) {
			start = (start + 0x3ff) & ~0x3ff;
			res->start = start;
		}
	}
}


/*
 *  Handle resources of PCI devices.  If the world were perfect, we could
 *  just allocate all the resource regions and do nothing more.  It isn't.
 *  On the other hand, we cannot just re-allocate all devices, as it would
 *  require us to know lots of host bridge internals.  So we attempt to
 *  keep as much of the original configuration as possible, but tweak it
 *  when it's found to be wrong.
 *
 *  Known BIOS problems we have to work around:
 *	- I/O or memory regions not configured
 *	- regions configured, but not enabled in the command register
 *	- bogus I/O addresses above 64K used
 *	- expansion ROMs left enabled (this may sound harmless, but given
 *	  the fact the PCI specs explicitly allow address decoders to be
 *	  shared between expansion ROMs and other resource regions, it's
 *	  at least dangerous)
 *
 *  Our solution:
 *	(1) Allocate resources for all buses behind PCI-to-PCI bridges.
 *	    This gives us fixed barriers on where we can allocate.
 *	(2) Allocate resources for all enabled devices.  If there is
 *	    a collision, just mark the resource as unallocated. Also
 *	    disable expansion ROMs during this step.
 *	(3) Try to allocate resources for disabled devices.  If the
 *	    resources were assigned correctly, everything goes well,
 *	    if they weren't, they won't disturb allocation of other
 *	    resources.
 *	(4) Assign new addresses to resources which were either
 *	    not configured at all or misconfigured.  If explicitly
 *	    requested by the user, configure expansion ROM address
 *	    as well.
 */

static void __init
pcibios_allocate_bus_resources(struct list_head *bus_list)
{
	struct list_head *ln;
	struct pci_bus *bus;
	struct pci_dev *dev;
	int idx;
	struct resource *r, *pr;

	/* Depth-First Search on bus tree */
	for (ln=bus_list->next; ln != bus_list; ln=ln->next) {
		bus = pci_bus_b(ln);
		if ((dev = bus->self)) {
			for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_NUM_RESOURCES; idx++) {
				r = &dev->resource[idx];
				if (!r->start)
					continue;
				pr = pci_find_parent_resource(dev, r);
				if (!pr || request_resource(pr, r) < 0)
					printk(KERN_ERR "PCI: Cannot allocate resource region %d of bridge %s\n", idx, dev->slot_name);
			}
		}
		pcibios_allocate_bus_resources(&bus->children);
	}
}

static inline void alloc_resource(struct pci_dev *dev, int idx)
{
	struct resource *pr, *r = &dev->resource[idx];

	DBG("PCI:%x:%x:%x: Resource %08lx-%08lx (f=%lx)\n",
	    dev->bus->number, dev->devfn >> 3, dev->devfn & 7,
	    r->start, r->end, r->flags);
	pr = pci_find_parent_resource(dev, r);
	if (!pr || request_resource(pr, r) < 0) {
		printk(KERN_ERR "PCI: Cannot allocate resource region %d"
		       " of device %s\n", idx, dev->slot_name);
		/* We'll assign a new address later */
		r->end -= r->start;
		r->start = 0;
	}
}

static void __init
pcibios_allocate_resources(int pass)
{
	struct pci_dev *dev;
	int idx, disabled;
	u16 command;
	struct resource *r;

	pci_for_each_dev(dev) {
		pci_read_config_word(dev, PCI_COMMAND, &command);
		for(idx = 0; idx < 6; idx++) {
			r = &dev->resource[idx];
			if (r->parent)		/* Already allocated */
				continue;
			if (!r->start)		/* Not assigned at all */
				continue;
			if (r->end == 0xffffffff) {
				/* LongTrail OF quirk: unassigned */
				DBG("PCI: Resource %08lx-%08lx was unassigned\n", r->start, r->end);
				r->end -= r->start;
				r->start = 0;
				continue;
			}

			if (r->flags & IORESOURCE_IO)
				disabled = !(command & PCI_COMMAND_IO);
			else
				disabled = !(command & PCI_COMMAND_MEMORY);
			if (pass == disabled)
				alloc_resource(dev, idx);
		}
		if (pass)
			continue;
		r = &dev->resource[PCI_ROM_RESOURCE];
		if (r->flags & PCI_ROM_ADDRESS_ENABLE) {
			/* Turn the ROM off, leave the resource region, but keep it unregistered. */
			u32 reg;
			DBG("PCI: Switching off ROM of %s\n", dev->slot_name);
			r->flags &= ~PCI_ROM_ADDRESS_ENABLE;
			pci_read_config_dword(dev, dev->rom_base_reg, &reg);
			pci_write_config_dword(dev, dev->rom_base_reg, reg & ~PCI_ROM_ADDRESS_ENABLE);
		}
	}
}

static void __init
pcibios_assign_resources(void)
{
	struct pci_dev *dev;
	int idx;
	struct resource *r;

	pci_for_each_dev(dev) {
		int class = dev->class >> 8;

		/* Don't touch classless devices and host bridges */
		if (!class || class == PCI_CLASS_BRIDGE_HOST)
			continue;

		for(idx=0; idx<6; idx++) {
			r = &dev->resource[idx];
#if 0	/* we don't need this PC-ism */
			/*
			 *  Don't touch IDE controllers and I/O ports of video cards!
			 */
			if ((class == PCI_CLASS_STORAGE_IDE && idx < 4) ||
			    (class == PCI_CLASS_DISPLAY_VGA && (r->flags & IORESOURCE_IO)))
				continue;
#endif

			/*
			 *  We shall assign a new address to this resource, either because
			 *  the BIOS (sic) forgot to do so or because we have decided the old
			 *  address was unusable for some reason.
			 */
			if (!r->start && r->end &&
			    (!ppc_md.pcibios_enable_device_hook ||
			     !ppc_md.pcibios_enable_device_hook(dev, 1)))
				pci_assign_resource(dev, idx);
		}

		if (0) { /* don't assign ROMs */
			r = &dev->resource[PCI_ROM_RESOURCE];
			r->end -= r->start;
			r->start = 0;
			if (r->end)
				pci_assign_resource(dev, PCI_ROM_RESOURCE);
		}
	}
}


int
pcibios_enable_resources(struct pci_dev *dev)
{
	u16 cmd, old_cmd;
	int idx;
	struct resource *r;

	pci_read_config_word(dev, PCI_COMMAND, &cmd);
	old_cmd = cmd;
	for(idx=0; idx<6; idx++) {
		r = &dev->resource[idx];
		if (!r->start && r->end) {
			printk(KERN_ERR "PCI: Device %s not available because of resource collisions\n", dev->slot_name);
			return -EINVAL;
		}
		if (r->flags & IORESOURCE_IO)
			cmd |= PCI_COMMAND_IO;
		if (r->flags & IORESOURCE_MEM)
			cmd |= PCI_COMMAND_MEMORY;
	}
	if (dev->resource[PCI_ROM_RESOURCE].start)
		cmd |= PCI_COMMAND_MEMORY;
	if (cmd != old_cmd) {
		printk("PCI: Enabling device %s (%04x -> %04x)\n", dev->slot_name, old_cmd, cmd);
		pci_write_config_word(dev, PCI_COMMAND, cmd);
	}
	return 0;
}

struct pci_controller * __init
pcibios_alloc_controller(void)
{
	struct pci_controller *hose;

	hose = (struct pci_controller *)alloc_bootmem(sizeof(*hose));
	memset(hose, 0, sizeof(struct pci_controller));
	
	*hose_tail = hose;
	hose_tail = &hose->next;

	return hose;
}

static void
make_one_node_map(struct device_node* node, u8 pci_bus)
{
	int *bus_range;
	int len;
	
	if (pci_bus >= pci_bus_count)
		return;
	bus_range = (int *) get_property(node, "bus-range", &len);
	if (bus_range == NULL || len < 2 * sizeof(int)) {
		printk(KERN_WARNING "Can't get bus-range for %s\n",
			       node->full_name);
		return;
	}
	pci_to_OF_bus_map[pci_bus] = bus_range[0];
	
	for (node=node->child; node != 0;node = node->sibling) {
		struct pci_dev* dev;
		unsigned int *class_code, *reg;
		
		class_code = (unsigned int *) get_property(node, "class-code", 0);
		if (!class_code || ((*class_code >> 8) != PCI_CLASS_BRIDGE_PCI &&
			(*class_code >> 8) != PCI_CLASS_BRIDGE_CARDBUS))
			continue;
		reg = (unsigned int *)get_property(node, "reg", 0);
		if (!reg)
			continue;
		dev = pci_find_slot(pci_bus, ((reg[0] >> 8) & 0xff));
		if (!dev || !dev->subordinate)
			continue;
		make_one_node_map(node, dev->subordinate->number);
	}
}
		
void
pcibios_make_OF_bus_map(void)
{
	int i;
	struct pci_controller* hose;
	u8* of_prop_map;
	
	pci_to_OF_bus_map = (u8*)kmalloc(pci_bus_count, GFP_KERNEL);
	if (!pci_to_OF_bus_map) {
		printk(KERN_ERR "Can't allocate OF bus map !\n");
		return;
	}
	
	/* We fill the bus map with invalid values, that helps
	 * debugging.
	 */
	for (i=0; i<pci_bus_count; i++)
		pci_to_OF_bus_map[i] = 0xff;
	
	/* For each hose, we begin searching bridges */
	for(hose=hose_head; hose; hose=hose->next) {
		struct device_node* node;		
		node = (struct device_node *)hose->arch_data;
		if (!node)
			continue;
		make_one_node_map(node, hose->first_busno);
	}
	of_prop_map = get_property(find_path_device("/"), "pci-OF-bus-map", 0);
	if (of_prop_map)
		memcpy(of_prop_map, pci_to_OF_bus_map, pci_bus_count);
#ifdef DEBUG
	printk("PCI->OF bus map:\n");
	for (i=0; i<pci_bus_count; i++) {
		if (pci_to_OF_bus_map[i] == 0xff)
			continue;
		printk("%d -> %d\n", i, pci_to_OF_bus_map[i]);
	}
#endif	
}

static struct device_node*
scan_OF_childs_for_device(struct device_node* node, u8 bus, u8 dev_fn)
{
	struct device_node* sub_node;
	
	for (; node != 0;node = node->sibling) {
		unsigned int *class_code, *reg;
		
		reg = (unsigned int *) get_property(node, "reg", 0);
		if (reg && ((reg[0] >> 8) & 0xff) == dev_fn
			&& ((reg[0] >> 16) & 0xff) == bus)
			return node;

		/* For PCI<->PCI bridges or CardBus bridges, we go down */
		class_code = (unsigned int *) get_property(node, "class-code", 0);
		if (!class_code || ((*class_code >> 8) != PCI_CLASS_BRIDGE_PCI &&
			(*class_code >> 8) != PCI_CLASS_BRIDGE_CARDBUS))
			continue;
		sub_node = scan_OF_childs_for_device(node->child, bus, dev_fn);
		if (sub_node)
			return sub_node;
	}
	return NULL;
}

/* 
 * Scans the OF tree for a device node matching a PCI device
 */
struct device_node*
pci_device_to_OF_node(struct pci_dev *dev)
{
	struct pci_controller *hose;
	struct device_node *node;
	int bus;
	
	if (!have_of)
		return NULL;
		
	/* Lookup the hose */
	bus = dev->bus->number;
	hose = pci_bus_to_hose(bus);
	if (!hose)
		return NULL;

	/* Check it has an OF node associated */
	node = (struct device_node *) hose->arch_data;
	if (!node)
		return NULL;

	/* Fixup bus number according to what OF think it is. */
	if (pci_to_OF_bus_map)
		bus = pci_to_OF_bus_map[bus];
	if (bus == 0xff)
		return NULL;
		
	/* Now, lookup childs of the hose */
	return scan_OF_childs_for_device(node->child, bus, dev->devfn);
}

/* This routine is meant to be used early during boot, when the
 * PCI bus numbers have not yet been assigned, and you need to
 * issue PCI config cycles to an OF device.
 * It could also be used to "fix" RTAS config cycles if you want
 * to set pci_assign_all_busses to 1 and still use RTAS for PCI
 * config cycles.
 */
struct pci_controller*
pci_find_hose_for_OF_device(struct device_node* node)
{
	if (!have_of)
		return NULL;
	while(node) {
		struct pci_controller* hose;
		for (hose=hose_head;hose;hose=hose->next)
			if (hose->arch_data == node)
				return hose;
		node=node->parent;
	}
	return NULL;
}

/* 
 * Returns the PCI device matching a given OF node
 */
int
pci_device_from_OF_node(struct device_node* node, u8* bus, u8* devfn)
{
	unsigned int *reg;
	int i;
		
	if (!have_of)
		return -ENODEV;
	reg = (unsigned int *) get_property(node, "reg", 0);
	if (!reg)
		return -ENODEV;
	*bus = (reg[0] >> 16) & 0xff;
	for (i=0; pci_to_OF_bus_map && i<pci_bus_count; i++)
		if (pci_to_OF_bus_map[i] == *bus) {
			*bus = i;
			break;
		}
	*devfn = ((reg[0] >> 8) & 0xff);
	return 0;
}

void __init
pcibios_init(void)
{
	struct pci_controller *hose;
	struct pci_bus *bus;
	int next_busno, i;

	printk("PCI: Probing PCI hardware\n");

	/* Scan all of the recorded PCI controllers.  */
	for (next_busno = 0, hose = hose_head; hose; hose = hose->next) {
		if (pci_assign_all_busses)
			hose->first_busno = next_busno;
		hose->last_busno = 0xff;
		bus = pci_scan_bus(hose->first_busno, hose->ops, hose);
		if (hose->io_resource.flags) {
			unsigned long offs;

			offs = (unsigned long)hose->io_base_virt - isa_io_base;
			hose->io_resource.start += offs;
			hose->io_resource.end += offs;
			bus->resource[0] = &hose->io_resource;
		}
		for (i = 0; i < 3; ++i)
			if (hose->mem_resources[i].flags)
				bus->resource[i+1] = &hose->mem_resources[i];
		hose->bus = bus;
		hose->last_busno = bus->subordinate;
		if (pci_assign_all_busses || next_busno <= hose->last_busno)
			next_busno = hose->last_busno+1;
	}
	pci_bus_count = next_busno;

	/* OpenFirmware based machines need a map of OF bus
	 * numbers vs. kernel bus numbers since we may have to
	 * remap them.
	 */
	if (pci_assign_all_busses && have_of)
		pcibios_make_OF_bus_map();
		
	/* Call machine dependant fixup */
	if (ppc_md.pcibios_fixup)
		ppc_md.pcibios_fixup();

	/* Allocate and assign resources */
	pcibios_allocate_bus_resources(&pci_root_buses);
	pcibios_allocate_resources(0);
	pcibios_allocate_resources(1);
	pcibios_assign_resources();

#ifdef CONFIG_BLK_DEV_IDE
	/* OF fails to initialize IDE controllers on macs
	 * (and maybe other machines)
	 * 
	 * This late fixup is done here since I want it to happen after
	 * resource assignement, and there's no "late-init" arch hook
	 * 
	 * Ideally, this should be moved to the IDE layer, but we need
	 * to check specifically with Andre Hedrick how to do it cleanly
	 * since the common IDE code seem to care about the fact that the
	 * BIOS may have disabled a controller.
	 * 
	 * -- BenH
	 */
	if (_machine == _MACH_Pmac) {
		struct pci_dev *dev;
		pci_for_each_dev(dev)
		{
			if ((dev->class >> 16) == PCI_BASE_CLASS_STORAGE)
				pci_enable_device(dev);
		}
	}
#endif /* CONFIG_BLK_DEV_IDE */
}

int __init
pcibios_assign_all_busses(void)
{
	return pci_assign_all_busses;
}

void __init
pcibios_fixup_pbus_ranges(struct pci_bus * bus, struct pbus_set_ranges_data * ranges)
{
	ranges->io_start -= bus->resource[0]->start;
	ranges->io_end -= bus->resource[0]->start;
	ranges->mem_start -= bus->resource[1]->start;
	ranges->mem_end -= bus->resource[1]->start;
}

unsigned long resource_fixup(struct pci_dev * dev, struct resource * res,
			     unsigned long start, unsigned long size)
{
	return start;
}

void __init pcibios_fixup_bus(struct pci_bus *bus)
{
	struct pci_controller *hose;

	pci_read_bridge_bases(bus);

	hose = pci_bus_to_hose(bus->number);

	/* Apply pci_mem_offset to bridge mem resource */
	if (hose->first_busno != bus->number)
		if (bus->resource[1]->start && (bus->resource[1]->end != -1))
		{
			bus->resource[1]->start += hose->pci_mem_offset;
			bus->resource[1]->end += hose->pci_mem_offset;
		}

	if ( ppc_md.pcibios_fixup_bus )
		ppc_md.pcibios_fixup_bus(bus);
}

char __init *pcibios_setup(char *str)
{
	return str;
}

/* the next one is stolen from the alpha port... */
void __init
pcibios_update_irq(struct pci_dev *dev, int irq)
{
	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
	/* XXX FIXME - update OF device tree node interrupt property */
}

int pcibios_enable_device(struct pci_dev *dev)
{
	u16 cmd, old_cmd;
	int idx;
	struct resource *r;

	if (ppc_md.pcibios_enable_device_hook)
		if (ppc_md.pcibios_enable_device_hook(dev, 0))
			return -EINVAL;
			
	pci_read_config_word(dev, PCI_COMMAND, &cmd);
	old_cmd = cmd;
	for (idx=0; idx<6; idx++) {
		r = &dev->resource[idx];
		if (!r->start && r->end) {
			printk(KERN_ERR "PCI: Device %s not available because of resource collisions\n", dev->slot_name);
			return -EINVAL;
		}
		if (r->flags & IORESOURCE_IO)
			cmd |= PCI_COMMAND_IO;
		if (r->flags & IORESOURCE_MEM)
			cmd |= PCI_COMMAND_MEMORY;
	}
	if (cmd != old_cmd) {
		printk("PCI: Enabling device %s (%04x -> %04x)\n",
		       dev->slot_name, old_cmd, cmd);
		pci_write_config_word(dev, PCI_COMMAND, cmd);
	}
	return 0;
}

struct pci_controller*
pci_bus_to_hose(int bus)
{
	struct pci_controller* hose = hose_head;

	for (; hose; hose = hose->next)
		if (bus >= hose->first_busno && bus <= hose->last_busno)
			return hose;
	return NULL;
}

void*
pci_bus_io_base(unsigned int bus)
{
	struct pci_controller *hose;

	hose = pci_bus_to_hose(bus);
	if (!hose)
		return NULL;
	return hose->io_base_virt;
}

unsigned long
pci_bus_io_base_phys(unsigned int bus)
{
	struct pci_controller *hose;

	hose = pci_bus_to_hose(bus);
	if (!hose)
		return 0;
	return hose->io_base_phys;
}

unsigned long
pci_bus_mem_base_phys(unsigned int bus)
{
	struct pci_controller *hose;

	hose = pci_bus_to_hose(bus);
	if (!hose)
		return 0;
	return hose->pci_mem_offset;
}

#ifdef CONFIG_POWER4
extern unsigned long pci_address_offset(int, unsigned int);
#endif /* CONFIG_POWER4 */

unsigned long
pci_resource_to_bus(struct pci_dev *pdev, struct resource *res)
{
	/* Hack alert again ! See comments in chrp_pci.c
	 */
#ifdef CONFIG_POWER4
	unsigned long offset = pci_address_offset(pdev->bus->number, res->flags);
	return res->start - offset;
#else /* CONFIG_POWER4 */
	struct pci_controller* hose =
		(struct pci_controller *)pdev->sysdata;
	if (hose && res->flags & IORESOURCE_MEM)
		return res->start - hose->pci_mem_offset;
	/* We may want to do something with IOs here... */
	return res->start;
#endif	
}

/* Obsolete functions. Should be removed once the symbios driver
 * is fixed
 */
unsigned long
phys_to_bus(unsigned long pa)
{
	struct pci_controller *hose;
	int i;

	for (hose = hose_head; hose; hose = hose->next) {
		for (i = 0; i < 3; ++i) {
			if (pa >= hose->mem_resources[i].start
			    && pa <= hose->mem_resources[i].end) {
				/*
				 * XXX the hose->pci_mem_offset really
				 * only applies to mem_resources[0].
				 * We need a way to store an offset for
				 * the others.  -- paulus
				 */
				if (i == 0)
					pa -= hose->pci_mem_offset;
				return pa;
			}
		}
	}
	/* hmmm, didn't find it */
	return 0;
}

unsigned long
pci_phys_to_bus(unsigned long pa, int busnr)
{
#ifdef CONFIG_POWER4
	return pa - pci_address_offset(busnr, IORESOURCE_MEM);
#else /* CONFIG_POWER4 */
	struct pci_controller* hose = pci_bus_to_hose(busnr);
	if (!hose)
		return pa;
	return pa - hose->pci_mem_offset;
#endif
}

unsigned long
pci_bus_to_phys(unsigned int ba, int busnr)
{
#ifdef CONFIG_POWER4
	return ba + pci_address_offset(dev->bus->number, IORESOURCE_MEM);
#else /* CONFIG_POWER4 */
	struct pci_controller* hose = pci_bus_to_hose(busnr);
	if (!hose)
		return ba;
	return ba + hose->pci_mem_offset;
#endif
}

/* Provide information on locations of various I/O regions in physical
 * memory.  Do this on a per-card basis so that we choose the right
 * root bridge.
 * Note that the returned IO or memory base is a physical address
 */

long
sys_pciconfig_iobase(long which, unsigned long bus, unsigned long devfn)
{
	struct pci_controller* hose = pci_bus_to_hose(bus);
	long result = -EOPNOTSUPP;

	if (!hose)
		return -ENODEV;
	
	switch (which) {
	case IOBASE_BRIDGE_NUMBER:
		return (long)hose->first_busno;
	case IOBASE_MEMORY:
		return (long)hose->pci_mem_offset;
	case IOBASE_IO:
		return (long)hose->io_base_phys;
	case IOBASE_ISA_IO:
		return (long)isa_io_base;
	case IOBASE_ISA_MEM:
		return (long)isa_mem_base;
	}

	return result;
}

/*
 * Null PCI config access functions, for the case when we can't
 * find a hose.
 */
#define NULL_PCI_OP(rw, size, type)					\
static int								\
null_##rw##_config_##size(struct pci_dev *dev, int offset, type val)	\
{									\
	return PCIBIOS_DEVICE_NOT_FOUND;    				\
}

NULL_PCI_OP(read, byte, u8 *)
NULL_PCI_OP(read, word, u16 *)
NULL_PCI_OP(read, dword, u32 *)
NULL_PCI_OP(write, byte, u8)
NULL_PCI_OP(write, word, u16)
NULL_PCI_OP(write, dword, u32)

static struct pci_ops null_pci_ops =
{
	null_read_config_byte,
	null_read_config_word,
	null_read_config_dword,
	null_write_config_byte,
	null_write_config_word,
	null_write_config_dword
};

/*
 * These functions are used early on before PCI scanning is done
 * and all of the pci_dev and pci_bus structures have been created.
 */
static struct pci_dev *
fake_pci_dev(struct pci_controller *hose, int busnr, int devfn)
{
	static struct pci_dev dev;
	static struct pci_bus bus;

	if (hose == 0) {
		hose = pci_bus_to_hose(busnr);
		if (hose == 0)
			printk(KERN_ERR "Can't find hose for PCI bus %d!\n", busnr);
	}
	dev.bus = &bus;
	dev.sysdata = hose;
	dev.devfn = devfn;
	bus.number = busnr;
	bus.ops = hose? hose->ops: &null_pci_ops;
	return &dev;
}

#define EARLY_PCI_OP(rw, size, type)					\
int early_##rw##_config_##size(struct pci_controller *hose, int bus,	\
			       int devfn, int offset, type value)	\
{									\
	return pci_##rw##_config_##size(fake_pci_dev(hose, bus, devfn),	\
					offset, value);			\
}

EARLY_PCI_OP(read, byte, u8 *)
EARLY_PCI_OP(read, word, u16 *)
EARLY_PCI_OP(read, dword, u32 *)
EARLY_PCI_OP(write, byte, u8)
EARLY_PCI_OP(write, word, u16)
EARLY_PCI_OP(write, dword, u32)