pci.c

一个2.4.21版本的嵌入式linux内核

	       struct resource *res, struct resource **conflict)
{
	struct pci_bus *bus;
	struct pci_dev *dev;
	struct resource *r;
	struct list_head *ln;
	int i;

	for (r = pr->child; r != NULL; r = r->sibling) {
		if (r->end >= res->start && res->end >= r->start) {
			*conflict = r;
			return 1;
		}
	}
	for (ln = parent->children.next; ln != &parent->children;
	     ln = ln->next) {
		bus = pci_bus_b(ln);
		for (i = 0; i < 4; ++i) {
			if ((r = bus->resource[i]) == NULL)
				continue;
			if (!r->flags || r->start > r->end || r == res)
				continue;
			if (pci_find_parent_resource(bus->self, r) != pr)
				continue;
			if (r->end >= res->start && res->end >= r->start) {
				*conflict = r;
				return 1;
			}
		}
	}
	for (ln = parent->devices.next; ln != &parent->devices; ln=ln->next) {
		dev = pci_dev_b(ln);
		for (i = 0; i < 6; ++i) {
			r = &dev->resource[i];
			if (!r->flags || (r->flags & IORESOURCE_UNSET))
				continue;
			if (pci_find_parent_resource(bus->self, r) != pr)
				continue;
			if (r->end >= res->start && res->end >= r->start) {
				*conflict = r;
				return 1;
			}
		}
	}
	return 0;
}

static void __init
update_bridge_base(struct pci_bus *bus, int i)
{
	struct resource *res = bus->resource[i];
	u8 io_base_lo, io_limit_lo;
	u16 mem_base, mem_limit;
	u16 cmd;
	unsigned long start, end, off;
	struct pci_dev *dev = bus->self;
	struct pci_controller *hose = dev->sysdata;

	if (!hose) {
		printk("update_bridge_base: no hose?\n");
		return;
	}
	pci_read_config_word(dev, PCI_COMMAND, &cmd);
	pci_write_config_word(dev, PCI_COMMAND,
			      cmd & ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY));
	if (res->flags & IORESOURCE_IO) {
		u16 bu;
		off = (unsigned long) hose->io_base_virt - isa_io_base;
		start = res->start - off;
		end = res->end - off;
		pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo);
		pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo);
		pci_read_config_word(dev, PCI_IO_BASE_UPPER16, &bu);
		io_limit_lo &= PCI_IO_RANGE_TYPE_MASK;
		if (io_base_lo == PCI_IO_RANGE_TYPE_16 && end > 0xffff) {
			printk(KERN_ERR "bridge only supports 16-bit I/O!\n");
			goto out;
		}
		io_base_lo |= (start >> 8) & PCI_IO_RANGE_MASK;
		io_limit_lo |= (end >> 8) & PCI_IO_RANGE_MASK;
		pci_write_config_word(dev, PCI_IO_BASE_UPPER16, start >> 16);
		pci_write_config_word(dev, PCI_IO_LIMIT_UPPER16, end >> 16);
		pci_write_config_byte(dev, PCI_IO_BASE, io_base_lo);
		pci_write_config_byte(dev, PCI_IO_LIMIT, io_limit_lo);

	} else if ((res->flags & (IORESOURCE_MEM | IORESOURCE_PREFETCH))
		   == IORESOURCE_MEM) {
		off = hose->pci_mem_offset;
		mem_base = ((res->start - off) >> 16) & PCI_MEMORY_RANGE_MASK;
		mem_limit = ((res->end - off) >> 16) & PCI_MEMORY_RANGE_MASK;
		pci_write_config_word(dev, PCI_MEMORY_BASE, mem_base);
		pci_write_config_word(dev, PCI_MEMORY_LIMIT, mem_limit);

	} else if ((res->flags & (IORESOURCE_MEM | IORESOURCE_PREFETCH))
		   == (IORESOURCE_MEM | IORESOURCE_PREFETCH)) {
		off = hose->pci_mem_offset;
		mem_base = ((res->start - off) >> 16) & PCI_PREF_RANGE_MASK;
		mem_limit = ((res->end - off) >> 16) & PCI_PREF_RANGE_MASK;
		pci_write_config_word(dev, PCI_PREF_MEMORY_BASE, mem_base);
		pci_write_config_word(dev, PCI_PREF_MEMORY_LIMIT, mem_limit);

	} else {
		DBG(KERN_ERR "PCI: ugh, bridge %s res %d has flags=%lx\n",
		    dev->slot_name, i, res->flags);
	}
 out:
	pci_write_config_word(dev, PCI_COMMAND, cmd);
}

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

	DBG("PCI:%s: Resource %d: %08lx-%08lx (f=%lx)\n",
	    dev->slot_name, idx, 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);
		if (pr)
			DBG("PCI:  parent is %p: %08lx-%08lx (f=%lx)\n",
			    pr, pr->start, pr->end, pr->flags);
		/* We'll assign a new address later */
		r->flags |= IORESOURCE_UNSET;
		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->flags || (r->flags & IORESOURCE_UNSET))
				continue;	/* Not assigned at all */
			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];

			/*
			 * 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->flags & IORESOURCE_UNSET) && 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);
#endif
	}
}


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->flags & IORESOURCE_UNSET) {
			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;
}

static int next_controller_index;

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;

	hose->index = next_controller_index++;

	return hose;
}

#ifdef CONFIG_ALL_PPC
/*
 * Functions below are used on OpenFirmware machines.
 */
static void __openfirmware
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 __openfirmware
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	
}

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;