pci.c

一个2.4.21版本的嵌入式linux内核

/*
 * 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/sections.h>
#include <asm/pci-bridge.h>
#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/uaccess.h>

#undef 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;

void pcibios_make_OF_bus_map(void);

static int pci_relocate_bridge_resource(struct pci_bus *bus, int i);
static int probe_resource(struct pci_bus *parent, struct resource *pr,
			  struct resource *res, struct resource **conflict);
static void update_bridge_base(struct pci_bus *bus, int i);
static void pcibios_fixup_resources(struct pci_dev* dev);
static void fixup_broken_pcnet32(struct pci_dev* dev);
static int reparent_resources(struct resource *parent, struct resource *res);
static void fixup_rev1_53c810(struct pci_dev* dev);
static void fixup_cpc710_pci64(struct pci_dev* dev);
#ifdef CONFIG_ALL_PPC
static void pcibios_fixup_cardbus(struct pci_dev* dev);
static u8* pci_to_OF_bus_map;
#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_VENDOR_ID_TRIDENT,	PCI_ANY_ID,			fixup_broken_pcnet32 },
	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_NCR,	PCI_DEVICE_ID_NCR_53C810,	fixup_rev1_53c810 },
	{ PCI_FIXUP_HEADER,	PCI_VENDOR_ID_IBM,	PCI_DEVICE_ID_IBM_CPC710_PCI64,	fixup_cpc710_pci64},
	{ 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_ANY_ID,			pcibios_fixup_cardbus }, 
#endif /* CONFIG_ALL_PPC */
 	{ 0 }
};

static void
fixup_rev1_53c810(struct pci_dev* dev)
{
	/* rev 1 ncr53c810 chips don't set the class at all which means
	 * they don't get their resources remapped. Fix that here.
	 */

	if ((dev->class == PCI_CLASS_NOT_DEFINED)) {
		printk("NCR 53c810 rev 1 detected, setting PCI class.\n");
		dev->class = PCI_CLASS_STORAGE_SCSI;
	}
}

static void
fixup_broken_pcnet32(struct pci_dev* dev)
{
	if ((dev->class>>8 == PCI_CLASS_NETWORK_ETHERNET)) {
		dev->vendor = PCI_VENDOR_ID_AMD;
		pci_write_config_word(dev, PCI_VENDOR_ID, PCI_VENDOR_ID_AMD);
		pci_name_device(dev);
	}
}

static void
fixup_cpc710_pci64(struct pci_dev* dev)
{
	/* Hide the PCI64 BARs from the kernel as their content doesn't
	 * fit well in the resource management
	 */
	dev->resource[0].start = dev->resource[0].end = 0;
	dev->resource[0].flags = 0;
	dev->resource[1].start = dev->resource[1].end = 0;
	dev->resource[1].flags = 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;
	unsigned long io_offset;
	
	new = res->start;
	res->flags &= ~IORESOURCE_UNSET;
	if (hose && res->flags & IORESOURCE_IO) {
		io_offset = (unsigned long)hose->io_base_virt - isa_io_base;
		new -= io_offset;
	}
	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);
	}
	printk(KERN_INFO "PCI: moved device %s resource %d (%lx) to %x\n",
	       dev->slot_name, resource, res->flags,
	       new & ~PCI_REGION_FLAG_MASK);
}

static void
pcibios_fixup_resources(struct pci_dev *dev)
{
	struct pci_controller* hose = (struct pci_controller *)dev->sysdata;
	int i;
	unsigned long offset;

	if (!hose) {
		printk(KERN_ERR "No hose for PCI dev %s!\n", dev->slot_name);
		return;
	}
	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
		struct resource *res = dev->resource + i;
		if (!res->flags)
			continue;
		if (!res->start || res->end == 0xffffffff) {
			DBG("PCI:%s Resource %d [%08lx-%08lx] is unassigned\n",
			    dev->slot_name, i, res->start, res->end);
			res->end -= res->start;
			res->start = 0;
			res->flags |= IORESOURCE_UNSET;
			continue;
		}
		offset = 0;
		if (res->flags & IORESOURCE_MEM) {
			offset = hose->pci_mem_offset;
		} else if (res->flags & IORESOURCE_IO) {
			offset = (unsigned long) hose->io_base_virt
				- isa_io_base;
		}
		if (offset != 0) {
			res->start += offset;
			res->end += offset;
#ifdef DEBUG
			printk("Fixup res %d (%lx) of dev %s: %lx -> %lx\n",
			       i, res->flags, dev->slot_name,
			       res->start - offset, res->start);
#endif
		}
	}

	/* Call machine specific resource fixup */
	if (ppc_md.pcibios_fixup_resources)
		ppc_md.pcibios_fixup_resources(dev);
}

#ifdef CONFIG_ALL_PPC
static void
pcibios_fixup_cardbus(struct pci_dev* dev)
{
	if (_machine != _MACH_Pmac)
		return;
	/*
	 * Fix the interrupt routing on the various cardbus bridges
	 * used on powerbooks
	 */
	if (dev->vendor != PCI_VENDOR_ID_TI)
		return;
	if (dev->device == PCI_DEVICE_ID_TI_1130 ||
	    dev->device == PCI_DEVICE_ID_TI_1131) {
		u8 val;
	    	/* Enable PCI interrupt */
		if (pci_read_config_byte(dev, 0x91, &val) == 0)
			pci_write_config_byte(dev, 0x91, val | 0x30);
		/* Disable ISA interrupt mode */	
		if (pci_read_config_byte(dev, 0x92, &val) == 0)
			pci_write_config_byte(dev, 0x92, val & ~0x06);
	}
	if (dev->device == PCI_DEVICE_ID_TI_1210 ||
	    dev->device == PCI_DEVICE_ID_TI_1211 ||
	    dev->device == PCI_DEVICE_ID_TI_1410) {
		u8 val;
		/* 0x8c == TI122X_IRQMUX, 2 says to route the INTA
		   signal out the MFUNC0 pin */
		if (pci_read_config_byte(dev, 0x8c, &val) == 0)
			pci_write_config_byte(dev, 0x8c, (val & ~0x0f) | 2);
		/* Disable ISA interrupt mode */	
		if (pci_read_config_byte(dev, 0x92, &val) == 0)
			pci_write_config_byte(dev, 0x92, val & ~0x06);
	}
}
#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,
		       unsigned long align)
{
	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;
	int i;
	struct resource *res, *pr;

	/* Depth-First Search on bus tree */
	for (ln = bus_list->next; ln != bus_list; ln=ln->next) {
		bus = pci_bus_b(ln);
		for (i = 0; i < 4; ++i) {
			if ((res = bus->resource[i]) == NULL || !res->flags
			    || res->start > res->end)
				continue;
			if (bus->parent == NULL)
				pr = (res->flags & IORESOURCE_IO)?
					&ioport_resource: &iomem_resource;
			else {
				pr = pci_find_parent_resource(bus->self, res);
				if (pr == res) {
					/* this happens when the generic PCI
					 * code (wrongly) decides that this
					 * bridge is transparent  -- paulus
					 */
					continue;
				}
			}

			DBG("PCI: bridge rsrc %lx..%lx (%lx), parent %p\n",
			    res->start, res->end, res->flags, pr);
			if (pr) {
				if (request_resource(pr, res) == 0)
					continue;
				/*
				 * Must be a conflict with an existing entry.
				 * Move that entry (or entries) under the
				 * bridge resource and try again.
				 */
				if (reparent_resources(pr, res) == 0)
					continue;
			}
			printk(KERN_ERR "PCI: Cannot allocate resource region "
			       "%d of PCI bridge %d\n", i, bus->number);
			if (pci_relocate_bridge_resource(bus, i))
				bus->resource[i] = NULL;
		}
		pcibios_allocate_bus_resources(&bus->children);
	}
}

/*
 * Reparent resource children of pr that conflict with res
 * under res, and make res replace those children.
 */
static int __init
reparent_resources(struct resource *parent, struct resource *res)
{
	struct resource *p, **pp;
	struct resource **firstpp = NULL;

	for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
		if (p->end < res->start)
			continue;
		if (res->end < p->start)
			break;
		if (p->start < res->start || p->end > res->end)
			return -1;	/* not completely contained */
		if (firstpp == NULL)
			firstpp = pp;
	}
	if (firstpp == NULL)
		return -1;	/* didn't find any conflicting entries? */
	res->parent = parent;
	res->child = *firstpp;
	res->sibling = *pp;
	*firstpp = res;
	*pp = NULL;
	for (p = res->child; p != NULL; p = p->sibling) {
		p->parent = res;
		DBG(KERN_INFO "PCI: reparented %s [%lx..%lx] under %s\n",
		    p->name, p->start, p->end, res->name);
	}
	return 0;
}

/*
 * A bridge has been allocated a range which is outside the range
 * of its parent bridge, so it needs to be moved.
 */
static int __init
pci_relocate_bridge_resource(struct pci_bus *bus, int i)
{
	struct resource *res, *pr, *conflict;
	unsigned long try, size;
	int j;
	struct pci_bus *parent = bus->parent;

	if (parent == NULL) {
		/* shouldn't ever happen */
		printk(KERN_ERR "PCI: can't move host bridge resource\n");
		return -1;
	}
	res = bus->resource[i];
	pr = NULL;
	for (j = 0; j < 4; j++) {
		struct resource *r = parent->resource[j];
		if (!r)
			continue;
		if ((res->flags ^ r->flags) & (IORESOURCE_IO | IORESOURCE_MEM))
			continue;
		if (!((res->flags ^ r->flags) & IORESOURCE_PREFETCH)) {
			pr = r;
			break;
		}
		if (res->flags & IORESOURCE_PREFETCH)
			pr = r;
	}
	if (pr == NULL)
		return -1;
	size = res->end - res->start;
	if (pr->start > pr->end || size > pr->end - pr->start)
		return -1;
	try = pr->end + 1;
	for (;;) {
		try &= ~0xfffUL;
		if (res->flags & IORESOURCE_MEM)
			try &= ~0xfffffUL;
		res->start = try - size - 1;
		res->end = try - 1;
		if (try <= size || res->start < pr->start)
			return -1;
		if (probe_resource(bus->parent, pr, res, &conflict) == 0)
			break;
		if (conflict->start <= pr->start + size)
			return -1;
		try = conflict->start;
	}
	if (request_resource(pr, res)) {
		DBG(KERN_ERR "PCI: huh? couldn't move to %lx..%lx\n",
		    res->start, res->end);
		return -1;		/* "can't happen" */
	}
	update_bridge_base(bus, i);
	printk(KERN_INFO "PCI: bridge %d resource %d moved to %lx..%lx\n",
	       bus->number, i, res->start, res->end);
	return 0;
}

static int __init
probe_resource(struct pci_bus *parent, struct resource *pr,