pci_ops_auto.c

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#include <stddef.h>
#include <console/console.h>
#include <arch/io.h>
#include <arch/pciconf.h>
#include <device/pci.h>
#include <device/pci_ids.h>
#include <device/pci_ops.h>

/*
 * Before we decide to use direct hardware access mechanisms, we try to do some
 * trivial checks to ensure it at least _seems_ to be working -- we just test
 * whether bus 00 contains a host bridge (this is similar to checking
 * techniques used in XFree86, but ours should be more reliable since we
 * attempt to make use of direct access hints provided by the PCI BIOS).
 *
 * This should be close to trivial, but it isn't, because there are buggy
 * chipsets (yes, you guessed it, by Intel and Compaq) that have no class ID.
 */
static int pci_sanity_check(const struct pci_bus_operations *o)
{
        uint16_t class, vendor;
        unsigned bus;
        int devfn;
        struct bus pbus; /* Dummy device */
#define PCI_CLASS_BRIDGE_HOST           0x0600
#define PCI_CLASS_DISPLAY_VGA           0x0300
#define PCI_VENDOR_ID_COMPAQ            0x0e11
#define PCI_VENDOR_ID_INTEL             0x8086
#define PCI_VENDOR_ID_MOTOROLA          0x1057

        for (bus = 0, devfn = 0; devfn < 0x100; devfn++) {
                class = o->read16(&pbus, bus, devfn, PCI_CLASS_DEVICE);
                vendor = o->read16(&pbus, bus, devfn, PCI_VENDOR_ID);
                if (((class == PCI_CLASS_BRIDGE_HOST) || (class == PCI_CLASS_DISPLAY_VGA)) ||
                        ((vendor == PCI_VENDOR_ID_INTEL) || (vendor == PCI_VENDOR_ID_COMPAQ) ||
                                (vendor == PCI_VENDOR_ID_MOTOROLA))) { 
                        return 1;
                }
        }
        printk_err("PCI: Sanity check failed\n");
        return 0;
}

const struct pci_bus_operations *pci_check_direct(void)
{
        unsigned int tmp;

        /*
         * Check if configuration type 1 works.
         */
        {
                outb(0x01, 0xCFB);
                tmp = inl(0xCF8);
                outl(0x80000000, 0xCF8);
                if ((inl(0xCF8) == 0x80000000) && 
                        pci_sanity_check(&pci_cf8_conf1)) 
                {
                        outl(tmp, 0xCF8);
                        printk_debug("PCI: Using configuration type 1\n");
                        return &pci_cf8_conf1;
                }
                outl(tmp, 0xCF8);
        }

        /*
         * Check if configuration type 2 works.
         */
        {
                outb(0x00, 0xCFB);
                outb(0x00, 0xCF8);
                outb(0x00, 0xCFA);
                if ((inb(0xCF8) == 0x00 && inb(0xCFA) == 0x00) &&
                        pci_sanity_check(&pci_cf8_conf2))
                {
                        printk_debug("PCI: Using configuration type 2\n");
                        return &pci_cf8_conf2;
                }
        }

        die("pci_check_direct failed\n");
        return NULL;
}

/** Set the method to be used for PCI, type I or type II
 */
void pci_set_method(device_t dev)
{
        printk_info("Finding PCI configuration type.\n");
        dev->ops->ops_pci_bus = pci_check_direct();
        post_code(0x5f);
}

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