linux/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;
struct pci_bus *pci_root_bus = NULL;
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;
		}
	}

	printk("PCI: Probing PCI hardware (bus %02x)\n", busnum);

	return pci_scan_bus(busnum, &pci_root_ops, NULL);
}

extern u8 pci_cache_line_size;

static int __init pcibios_init(void)
{
	struct cpuinfo_x86 *c = &boot_cpu_data;

	if (!raw_pci_ops) {
		printk("PCI: System does not support PCI\n");
		return 0;
	}

	/*
	 * Assume PCI cacheline size of 32 bytes for all x86s except K7/K8
	 * and P4. It's also good for 386/486s (which actually have 16)
	 * as quite a few PCI devices do not support smaller values.
	 */
	pci_cache_line_size = 32 >> 2;
	if (c->x86 >= 6 && c->x86_vendor == X86_VENDOR_AMD)
		pci_cache_line_size = 64 >> 2;	/* K7 & K8 */
	else if (c->x86 > 6 && c->x86_vendor == X86_VENDOR_INTEL)
		pci_cache_line_size = 128 >> 2;	/* P4 */

	pcibios_resource_survey();

#ifdef CONFIG_PCI_BIOS
	if ((pci_probe & PCI_BIOS_SORT) && !(pci_probe & PCI_NO_SORT))
		pcibios_sort();
#endif
	return 0;
}

subsys_initcall(pcibios_init);

char * __devinit  pcibios_setup(char *str)
{
	if (!strcmp(str, "off")) {
		pci_probe = 0;
		return NULL;
	}
#ifdef CONFIG_PCI_BIOS
	else if (!strcmp(str, "bios")) {
		pci_probe = PCI_PROBE_BIOS;
		return NULL;
	} else if (!strcmp(str, "nobios")) {
		pci_probe &= ~PCI_PROBE_BIOS;
		return NULL;
	} else if (!strcmp(str, "nosort")) {
		pci_probe |= PCI_NO_SORT;
		return NULL;
	} else if (!strcmp(str, "biosirq")) {
		pci_probe |= PCI_BIOS_IRQ_SCAN;
		return NULL;
	}
#endif
#ifdef CONFIG_PCI_DIRECT
	else if (!strcmp(str, "conf1")) {
		pci_probe = PCI_PROBE_CONF1 | PCI_NO_CHECKS;
		return NULL;
	}
	else if (!strcmp(str, "conf2")) {
		pci_probe = PCI_PROBE_CONF2 | PCI_NO_CHECKS;
		return NULL;
	}
#endif
#ifdef CONFIG_PCI_MMCONFIG
	else if (!strcmp(str, "nommconf")) {
		pci_probe &= ~PCI_PROBE_MMCONF;
		return NULL;
	}
#endif
	else if (!strcmp(str, "noacpi")) {
		acpi_noirq_set();
		return NULL;
	}
#ifndef CONFIG_X86_VISWS
	else if (!strcmp(str, "usepirqmask")) {
		pci_probe |= PCI_USE_PIRQ_MASK;
		return NULL;
	} else if (!strncmp(str, "irqmask=", 8)) {
		pcibios_irq_mask = simple_strtol(str+8, NULL, 0);
		return NULL;
	} else if (!strncmp(str, "lastbus=", 8)) {
		pcibios_last_bus = simple_strtol(str+8, NULL, 0);
		return NULL;
	}
#endif
	else if (!strcmp(str, "rom")) {
		pci_probe |= PCI_ASSIGN_ROMS;
		return NULL;
	} else if (!strcmp(str, "assign-busses")) {
		pci_probe |= PCI_ASSIGN_ALL_BUSSES;
		return NULL;
	} else if (!strcmp(str, "routeirq")) {
		pci_routeirq = 1;
		return NULL;
	}
	return str;
}

unsigned int pcibios_assign_all_busses(void)
{
	return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
}

int pcibios_enable_device(struct pci_dev *dev, int mask)
{
	int err;

	if ((err = pcibios_enable_resources(dev, mask)) < 0)
		return err;

	return pcibios_enable_irq(dev);
}