fixup.c

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/*
 * Exceptions for specific devices. Usually work-arounds for fatal design flaws.
 * Derived from fixup.c of i386 tree.
 */

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

#include <asm/machvec.h>

/*
 * Fixup to mark boot BIOS video selected by BIOS before it changes
 *
 * From information provided by "Jon Smirl" <[email protected]>
 *
 * The standard boot ROM sequence for an x86 machine uses the BIOS
 * to select an initial video card for boot display. This boot video
 * card will have it's BIOS copied to C0000 in system RAM.
 * IORESOURCE_ROM_SHADOW is used to associate the boot video
 * card with this copy. On laptops this copy has to be used since
 * the main ROM may be compressed or combined with another image.
 * See pci_map_rom() for use of this flag. IORESOURCE_ROM_SHADOW
 * is marked here since the boot video device will be the only enabled
 * video device at this point.
 */

static void __devinit pci_fixup_video(struct pci_dev *pdev)
{
    struct pci_dev *bridge;
    struct pci_bus *bus;
    u16 config;

    if ((strcmp(ia64_platform_name, "dig") != 0)
        && (strcmp(ia64_platform_name, "hpzx1")  != 0))
        return;
    /* Maybe, this machine supports legacy memory map. */

    if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
        return;

    /* Is VGA routed to us? */
    bus = pdev->bus;
    while (bus) {
        bridge = bus->self;

        /*
         * From information provided by
         * "David Miller" <[email protected]>
         * The bridge control register is valid for PCI header
         * type BRIDGE, or CARDBUS. Host to PCI controllers use
         * PCI header type NORMAL.
         */
        if (bridge
            &&((bridge->hdr_type == PCI_HEADER_TYPE_BRIDGE)
               ||(bridge->hdr_type == PCI_HEADER_TYPE_CARDBUS))) {
            pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
                        &config);
            if (!(config & PCI_BRIDGE_CTL_VGA))
                return;
        }
        bus = bus->parent;
    }
    pci_read_config_word(pdev, PCI_COMMAND, &config);
    if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
        pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
        dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n");
    }
}
DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pci_fixup_video);