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


#include <linuxcomp.h>

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

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

#include "pci2.h"

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

unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2;

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.
 */

spinlock_t pci_config_lock = SPIN_LOCK_UNLOCKED;

/*
 * 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);
        for (ln=b->devices.next; ln != &b->devices; ln=ln->next) {
                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;

int __init pcibios_init(void)
{

        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;

        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_ACPI_PCI
        else if (!strcmp(str, "noacpi")) {
                pci_probe |= PCI_NO_ACPI_ROUTING;
                return NULL;
        }
#endif
#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;
        }
        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);
}