| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * 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 <linux/vgaarb.h> |
| #include <linux/screen_info.h> |
| |
| #include <asm/machvec.h> |
| |
| /* |
| * Fixup to mark boot BIOS video selected by BIOS before it changes |
| * |
| * From information provided by "Jon Smirl" <jonsmirl@gmail.com> |
| * |
| * 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 its BIOS copied to 0xC0000 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. Before marking the device |
| * with IORESOURCE_ROM_SHADOW check if a vga_default_device is already set |
| * by either arch code or vga-arbitration; if so only apply the fixup to this |
| * already-determined primary video card. |
| */ |
| |
| static void pci_fixup_video(struct pci_dev *pdev) |
| { |
| struct pci_dev *bridge; |
| struct pci_bus *bus; |
| u16 config; |
| struct resource *res; |
| |
| if ((strcmp(ia64_platform_name, "dig") != 0) |
| && (strcmp(ia64_platform_name, "hpzx1") != 0)) |
| return; |
| /* Maybe, this machine supports legacy memory map. */ |
| |
| /* Is VGA routed to us? */ |
| bus = pdev->bus; |
| while (bus) { |
| bridge = bus->self; |
| |
| /* |
| * From information provided by |
| * "David Miller" <davem@davemloft.net> |
| * The bridge control register is valid for PCI header |
| * type BRIDGE, or CARDBUS. Host to PCI controllers use |
| * PCI header type NORMAL. |
| */ |
| if (bridge && (pci_is_bridge(bridge))) { |
| pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, |
| &config); |
| if (!(config & PCI_BRIDGE_CTL_VGA)) |
| return; |
| } |
| bus = bus->parent; |
| } |
| if (!vga_default_device() || pdev == vga_default_device()) { |
| pci_read_config_word(pdev, PCI_COMMAND, &config); |
| if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { |
| res = &pdev->resource[PCI_ROM_RESOURCE]; |
| |
| pci_disable_rom(pdev); |
| if (res->parent) |
| release_resource(res); |
| |
| res->start = 0xC0000; |
| res->end = res->start + 0x20000 - 1; |
| res->flags = IORESOURCE_MEM | IORESOURCE_ROM_SHADOW | |
| IORESOURCE_PCI_FIXED; |
| dev_info(&pdev->dev, "Video device with shadowed ROM at %pR\n", |
| res); |
| } |
| } |
| } |
| DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_ANY_ID, PCI_ANY_ID, |
| PCI_CLASS_DISPLAY_VGA, 8, pci_fixup_video); |