linux/arch/ia64/pci/fixup.c
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   1/*
   2 * Exceptions for specific devices. Usually work-arounds for fatal design flaws.
   3 * Derived from fixup.c of i386 tree.
   4 */
   5
   6#include <linux/pci.h>
   7#include <linux/init.h>
   8#include <linux/vgaarb.h>
   9#include <linux/screen_info.h>
  10
  11#include <asm/machvec.h>
  12
  13/*
  14 * Fixup to mark boot BIOS video selected by BIOS before it changes
  15 *
  16 * From information provided by "Jon Smirl" <jonsmirl@gmail.com>
  17 *
  18 * The standard boot ROM sequence for an x86 machine uses the BIOS
  19 * to select an initial video card for boot display. This boot video
  20 * card will have it's BIOS copied to C0000 in system RAM.
  21 * IORESOURCE_ROM_SHADOW is used to associate the boot video
  22 * card with this copy. On laptops this copy has to be used since
  23 * the main ROM may be compressed or combined with another image.
  24 * See pci_map_rom() for use of this flag. Before marking the device
  25 * with IORESOURCE_ROM_SHADOW check if a vga_default_device is already set
  26 * by either arch cde or vga-arbitration, if so only apply the fixup to this
  27 * already determined primary video card.
  28 */
  29
  30static void pci_fixup_video(struct pci_dev *pdev)
  31{
  32        struct pci_dev *bridge;
  33        struct pci_bus *bus;
  34        u16 config;
  35
  36        if ((strcmp(ia64_platform_name, "dig") != 0)
  37            && (strcmp(ia64_platform_name, "hpzx1")  != 0))
  38                return;
  39        /* Maybe, this machine supports legacy memory map. */
  40
  41        /* Is VGA routed to us? */
  42        bus = pdev->bus;
  43        while (bus) {
  44                bridge = bus->self;
  45
  46                /*
  47                 * From information provided by
  48                 * "David Miller" <davem@davemloft.net>
  49                 * The bridge control register is valid for PCI header
  50                 * type BRIDGE, or CARDBUS. Host to PCI controllers use
  51                 * PCI header type NORMAL.
  52                 */
  53                if (bridge && (pci_is_bridge(bridge))) {
  54                        pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
  55                                                &config);
  56                        if (!(config & PCI_BRIDGE_CTL_VGA))
  57                                return;
  58                }
  59                bus = bus->parent;
  60        }
  61        if (!vga_default_device() || pdev == vga_default_device()) {
  62                pci_read_config_word(pdev, PCI_COMMAND, &config);
  63                if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
  64                        pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
  65                        dev_printk(KERN_DEBUG, &pdev->dev, "Video device with shadowed ROM\n");
  66                }
  67        }
  68}
  69DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_ANY_ID, PCI_ANY_ID,
  70                                PCI_CLASS_DISPLAY_VGA, 8, pci_fixup_video);
  71