pci.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

	
	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	
}

typedef int (*pci_OF_scan_iterator)(struct device_node* node, void* data);

static struct device_node* __openfirmware
scan_OF_pci_childs(struct device_node* node, pci_OF_scan_iterator filter, void* data)
{
	struct device_node* sub_node;
	
	for (; node != 0;node = node->sibling) {
		unsigned int *class_code;
		
		if (filter(node, data))
			return node;

		/* For PCI<->PCI bridges or CardBus bridges, we go down
		 * Note: some OFs create a parent node "multifunc-device" as
		 * a fake root for all functions of a multi-function device,
		 * we go down them as well.
		 */
		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)) &&
			strcmp(node->name, "multifunc-device"))
			continue;
		sub_node = scan_OF_pci_childs(node->child, filter, data);
		if (sub_node)
			return sub_node;
	}
	return NULL;
}

static int
scan_OF_pci_childs_iterator(struct device_node* node, void* data)
{
	unsigned int *reg;
	u8* fdata = (u8*)data;
		
	reg = (unsigned int *) get_property(node, "reg", 0);
	if (reg && ((reg[0] >> 8) & 0xff) == fdata[1]
		&& ((reg[0] >> 16) & 0xff) == fdata[0])
		return 1;
	return 0;
}

static struct device_node* __openfirmware
scan_OF_childs_for_device(struct device_node* node, u8 bus, u8 dev_fn)
{
	u8 filter_data[2] = {bus, dev_fn};

	return scan_OF_pci_childs(node, scan_OF_pci_childs_iterator, filter_data);
}

/* 
 * 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;
}

static int __openfirmware
find_OF_pci_device_filter(struct device_node* node, void* data)
{
	return ((void *)node == data);
}

/* 
 * 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;
	struct pci_controller* hose;
	struct pci_dev* dev;
		
	if (!have_of)
		return -ENODEV;
	/* Make sure it's really a PCI device */
	hose = pci_find_hose_for_OF_device(node);
	if (!hose || !hose->arch_data)
		return -ENODEV;
	if (!scan_OF_pci_childs(((struct device_node*)hose->arch_data)->child,
			find_OF_pci_device_filter, (void *)node))
		return -ENODEV;
	reg = (unsigned int *) get_property(node, "reg", 0);
	if (!reg)
		return -ENODEV;
	*bus = (reg[0] >> 16) & 0xff;
	*devfn = ((reg[0] >> 8) & 0xff);

	/* Ok, here we need some tweak. If we have already renumbered
	 * all busses, we can't rely on the OF bus number any more.
	 * the pci_to_OF_bus_map is not enough as several PCI busses
	 * may match the same OF bus number.
	 */
	if (!pci_to_OF_bus_map)
		return 0;
	pci_for_each_dev(dev) {
		if (pci_to_OF_bus_map[dev->bus->number] != *bus)
			continue;
		if (dev->devfn != *devfn)
			continue;
		*bus = dev->bus->number;
		return 0;
	}
	return -ENODEV;
}

void __init
pci_process_bridge_OF_ranges(struct pci_controller *hose,
			   struct device_node *dev, int primary)
{
	unsigned int *ranges, *prev;
	int rlen = 0;
	int memno = 0;
	struct resource *res;
	int np, na = prom_n_addr_cells(dev);
	np = na + 5;

	/* First we try to merge ranges to fix a problem with some pmacs
	 * that can have more than 3 ranges, fortunately using contiguous
	 * addresses -- BenH
	 */
	ranges = (unsigned int *) get_property(dev, "ranges", &rlen);
	prev = NULL;
	while ((rlen -= np * sizeof(unsigned int)) >= 0) {
		if (prev) {
			if (prev[0] == ranges[0] && prev[1] == ranges[1] &&
				(prev[2] + prev[na+4]) == ranges[2] &&
				(prev[na+2] + prev[na+4]) == ranges[na+2]) {
				prev[na+4] += ranges[na+4];
				ranges[0] = 0;
				ranges += np;
				continue;
			}
		}
		prev = ranges;
		ranges += np;
	}

	/*
	 * The ranges property is laid out as an array of elements,
	 * each of which comprises:
	 *   cells 0 - 2:	a PCI address
	 *   cells 3 or 3+4:	a CPU physical address
	 *			(size depending on dev->n_addr_cells)
	 *   cells 4+5 or 5+6:	the size of the range
	 */
	rlen = 0;
	hose->io_base_phys = 0;
	ranges = (unsigned int *) get_property(dev, "ranges", &rlen);
	while ((rlen -= np * sizeof(unsigned int)) >= 0) {
		res = NULL;
		switch (ranges[0] >> 24) {
		case 1:		/* I/O space */
			if (ranges[2] != 0)
				break;
			hose->io_base_phys = ranges[na+2];
			hose->io_base_virt = ioremap(ranges[na+2], ranges[na+4]);
			if (primary)
				isa_io_base = (unsigned long) hose->io_base_virt;
			res = &hose->io_resource;
			res->flags = IORESOURCE_IO;
			res->start = ranges[2];
			break;
		case 2:		/* memory space */
			memno = 0;
			if (ranges[1] == 0 && ranges[2] == 0
			    && ranges[na+4] <= (16 << 20)) {
				/* 1st 16MB, i.e. ISA memory area */
				if (primary)
					isa_mem_base = ranges[na+2];
				memno = 1;
			}
			while (memno < 3 && hose->mem_resources[memno].flags)
				++memno;
			if (memno == 0)
				hose->pci_mem_offset = ranges[na+2] - ranges[2];
			if (memno < 3) {
				res = &hose->mem_resources[memno];
				res->flags = IORESOURCE_MEM;
				res->start = ranges[na+2];
			}
			break;
		}
		if (res != NULL) {
			res->name = dev->full_name;
			res->end = res->start + ranges[na+4] - 1;
			res->parent = NULL;
			res->sibling = NULL;
			res->child = NULL;
		}
		ranges += np;
	}
}

/* We create the "pci-OF-bus-map" property now so it appears in the
 * /proc device tree
 */
void __init
pci_create_OF_bus_map(void)
{
	struct property* of_prop;
		
	of_prop = (struct property*) alloc_bootmem(sizeof(struct property) + 256);
	if (of_prop && find_path_device("/")) {
		memset(of_prop, -1, sizeof(struct property) + 256);
		of_prop->name = "pci-OF-bus-map";
		of_prop->length = 256;
		of_prop->value = (unsigned char *)&of_prop[1];
		prom_add_property(find_path_device("/"), of_prop);
	}
}
#endif /* CONFIG_ALL_PPC */

/*
 * This set of routines checks for PCI<->PCI bridges that have closed
 * IO resources and have child devices. It tries to re-open an IO
 * window on them. 
 * 
 * This is a _temporary_ fix to workaround a problem with Apple's OF
 * closing IO windows on P2P bridges when the OF drivers of cards
 * below this bridge don't claim any IO range (typically ATI or
 * Adaptec).
 * 
 * A more complete fix would be to use drivers/pci/setup-bus.c, which
 * involves a working pcibios_fixup_pbus_ranges(), some more care about
 * ordering when creating the host bus resources, and maybe a few more
 * minor tweaks
 */

/* Initialize bridges with base/limit values we have collected */
static void __init
do_update_p2p_io_resource(struct pci_bus *bus, int enable_vga)
{
	struct pci_dev *bridge = bus->self;
	struct pci_controller* hose = (struct pci_controller *)bridge->sysdata;
	u32 l;
	u16 w;
	struct resource res;
	
 	res = *(bus->resource[0]);

	DBG("Remapping Bus %d, bridge: %s\n", bus->number, bridge->name);
	res.start -= ((unsigned long) hose->io_base_virt - isa_io_base);
	res.end -= ((unsigned long) hose->io_base_virt - isa_io_base);
	DBG("  IO window: %08lx-%08lx\n", res.start, res.end);

	/* Set up the top and bottom of the PCI I/O segment for this bus. */
	pci_read_config_dword(bridge, PCI_IO_BASE, &l);
	l &= 0xffff000f;
	l |= (res.start >> 8) & 0x00f0;
	l |= res.end & 0xf000;
	pci_write_config_dword(bridge, PCI_IO_BASE, l);

	if ((l & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) {
		l = (res.start >> 16) | (res.end & 0xffff0000);
		pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, l);
	}

	pci_read_config_word(bridge, PCI_COMMAND, &w);
	w |= PCI_COMMAND_IO;
	pci_write_config_word(bridge, PCI_COMMAND, w);

#if 0 /* Enabling this causes XFree 4.2.0 to hang during PCI probe */
	if (enable_vga) {
		pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &w);
		w |= PCI_BRIDGE_CTL_VGA;
		pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, w);
	}
#endif
}

/* This function is pretty basic and actually quite broken for the
 * general case, it's enough for us right now though. It's supposed
 * to tell us if we need to open an IO range at all or not and what
 * size.
 */
static int __init
check_for_io_childs(struct pci_bus *bus, struct resource* res, int *found_vga)
{
	struct list_head *ln;
	int	i;
	int	rc = 0;

#define push_end(res, size) do { unsigned long __sz = (size) ; \
	res->end = ((res->end + __sz) / (__sz + 1)) * (__sz + 1) + __sz; \
    } while (0)

	for (ln=bus->devices.next; ln != &bus->devices; ln=ln->next) {
		struct pci_dev *dev = pci_dev_b(ln);
		u16 class = dev->class >> 8;

		if (class == PCI_CLASS_DISPLAY_VGA || class == PCI_CLASS_NOT_DEFINED_VGA)
			*found_vga = 1;
		if (class >> 8 == PCI_BASE_CLASS_BRIDGE && dev->subordinate)
			rc |= check_for_io_childs(dev->subordinate, res, found_vga);
		if (class == PCI_CLASS_BRIDGE_CARDBUS)
			push_end(res, 0xfff);

		for (i=0; i<PCI_NUM_RESOURCES; i++) {
			struct resource *r;
			unsigned long r_size;

			if (dev->class >> 8 == PCI_CLASS_BRIDGE_PCI && i >= PCI_BRIDGE_RESOURCES)
				continue;
			r = &dev->resource[i];
			r_size = r->end - r->start;
			if (r_size < 0xfff)
				r_size = 0xfff;
			if (r->flags & IORESOURCE_IO && (r_size) != 0) {
				rc = 1;
				push_end(res, r_size);
			}
		}
	}

	return rc;
}

/* Here we scan all P2P bridges of a given level that have a closed
 * IO window. Note that the test for the presence of a VGA card should
 * be improved to take into account already configured P2P bridges,
 * currently, we don't see them and might end up configuring 2 bridges
 * with VGA pass through enabled
 */
static void __init
do_fixup_p2p_level(struct pci_bus *bus)
{
	struct list_head *ln;
	int i;
	int has_vga = 0;
	
	for (ln=bus->children.next; ln != &bus->children; ln=ln->next) {
		struct pci_bus *b = pci_bus_b(ln);
		struct pci_dev *d = b->self;
		struct pci_controller* hose = (struct pci_controller *)d->sysdata;
		struct resource *res = b->resource[0];
		unsigned long max;
		int found_vga = 0;

		res->end = 0;
		res->start = 0x1000;
		
		if (!list_empty(&b->devices) && res && res->flags == 0 && res != bus->resource[0] &&
		    (d->class >> 8) == PCI_CLASS_BRIDGE_PCI &&
		    check_for_io_childs(b, res, &found_vga)) {
			u8 io_base_lo;

			printk(KERN_INFO "Fixing up IO bus %s\n", b->name);

			if (found_vga) {
				if (has_vga) {
					printk(KERN_WARNING "Skipping VGA, already active on bus segment\n");
					found_vga = 0;
				} else
					has_vga = 1;
			}
			pci_read_config_byte(d, PCI_IO_BASE, &io_base_lo);

			if ((io_base_lo & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32)
				max = ((unsigned long) hose->io_base_virt - isa_io_base) + 0xffffffff;
			else
				max = ((unsigned long) hose->io_base_virt - isa_io_base) + 0xffff;
			
			res->flags = IORESOURCE_IO;
			res->name = b->name;
			
			/* Find a resource in the parent where we can allocate */
			for (i = 0 ; i < 4; i++) {
				struct resource *r = bus->resource[i];
				if (!r)
					continue;
				if ((r->flags & IORESOURCE_IO) == 0)
					continue;
				DBG("Trying to allocate from %08lx, size %08lx from parent res %d: %08lx -> %08lx\n",
					res->start, res->end, i, r->start, r->end);
				
				if (allocate_resource(r, res, res->end + 1, res->start, max, res->end + 1, NULL, NULL) < 0) {
					DBG("Failed !\n");
					continue;
				}
				do_update_p2p_io_resource(b, found_vga);
				break;
			}
		}
		do_fixup_p2p_level(b);
	}
}

static void
pcibios_fixup_p2p_bridges(void)
{
	struct list_head *ln;

	for(ln=pci_root_buses.next; ln != &pci_root_buses; ln=ln->next) {
		struct pci_bus *b = pci_bus_b(ln);
		do_fixup_p2p_level(b);
	}
}

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

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

	/* There is a problem with bus renumbering currently. If
	 * you have 2 sibling pci<->pci bridges, and during PCI
	 * probe, the first one gets assigned a new number equal
	 * to the old number of the second one, you'll end up
	 * probing that branch with 2 bridges racing on the bus
	 * numbers.
	 * I work around this on pmac by adding a large offset
	 * between host bridges, though a better long term solution
	 * will have to be found in the generic code. --BenH
	 */
#ifdef CONFIG_ALL_PPC
	if (machine_is_compatible("MacRISC"))
		bus_offset = 0x10;
	else
#endif
		bus_offset = 1;
	/* 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);
		hose->last_busno = bus->subordinate;
		if (pci_assign_all_busses || next_busno <= hose->last_busno)
			next_busno = hose->last_busno + bus_offset;
	}
	pci_bus_count = next_busno;

	/* OpenFirmware based machines need a map of OF bus