Merge branch 'master'

[mirror_ubuntu-artful-kernel.git] / arch / i386 / pci / common.c

/*
 *	Low-Level PCI Support for PC
 *
 *	(c) 1999--2000 Martin Mares <mj@ucw.cz>
 */

#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/init.h>

#include <asm/acpi.h>
#include <asm/segment.h>
#include <asm/io.h>
#include <asm/smp.h>

#include "pci.h"

#ifdef CONFIG_PCI_BIOS
extern  void pcibios_sort(void);
#endif

unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
				PCI_PROBE_MMCONF;

int pci_routeirq;
int pcibios_last_bus = -1;
unsigned long pirq_table_addr;
struct pci_bus *pci_root_bus;
struct pci_raw_ops *raw_pci_ops;

static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
{
	return raw_pci_ops->read(0, bus->number, devfn, where, size, value);
}

static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 value)
{
	return raw_pci_ops->write(0, bus->number, devfn, where, size, value);
}

struct pci_ops pci_root_ops = {
	.read = pci_read,
	.write = pci_write,
};

/*
 * legacy, numa, and acpi all want to call pcibios_scan_root
 * from their initcalls. This flag prevents that.
 */
int pcibios_scanned;

/*
 * This interrupt-safe spinlock protects all accesses to PCI
 * configuration space.
 */
DEFINE_SPINLOCK(pci_config_lock);

/*
 * Several buggy motherboards address only 16 devices and mirror
 * them to next 16 IDs. We try to detect this `feature' on all
 * primary buses (those containing host bridges as they are
 * expected to be unique) and remove the ghost devices.
 */

static void __devinit pcibios_fixup_ghosts(struct pci_bus *b)
{
	struct list_head *ln, *mn;
	struct pci_dev *d, *e;
	int mirror = PCI_DEVFN(16,0);
	int seen_host_bridge = 0;
	int i;

	DBG("PCI: Scanning for ghost devices on bus %d\n", b->number);
	list_for_each(ln, &b->devices) {
		d = pci_dev_b(ln);
		if ((d->class >> 8) == PCI_CLASS_BRIDGE_HOST)
			seen_host_bridge++;
		for (mn=ln->next; mn != &b->devices; mn=mn->next) {
			e = pci_dev_b(mn);
			if (e->devfn != d->devfn + mirror ||
			    e->vendor != d->vendor ||
			    e->device != d->device ||
			    e->class != d->class)
				continue;
			for(i=0; i<PCI_NUM_RESOURCES; i++)
				if (e->resource[i].start != d->resource[i].start ||
				    e->resource[i].end != d->resource[i].end ||
				    e->resource[i].flags != d->resource[i].flags)
					continue;
			break;
		}
		if (mn == &b->devices)
			return;
	}
	if (!seen_host_bridge)
		return;
	printk(KERN_WARNING "PCI: Ignoring ghost devices on bus %02x\n", b->number);

	ln = &b->devices;
	while (ln->next != &b->devices) {
		d = pci_dev_b(ln->next);
		if (d->devfn >= mirror) {
			list_del(&d->global_list);
			list_del(&d->bus_list);
			kfree(d);
		} else
			ln = ln->next;
	}
}

/*
 *  Called after each bus is probed, but before its children
 *  are examined.
 */

void __devinit  pcibios_fixup_bus(struct pci_bus *b)
{
	pcibios_fixup_ghosts(b);
	pci_read_bridge_bases(b);
}


struct pci_bus * __devinit pcibios_scan_root(int busnum)
{
	struct pci_bus *bus = NULL;

	while ((bus = pci_find_next_bus(bus)) != NULL) {
		if (bus->number == busnum) {
			/* Already scanned */
			return bus;
		}
	}