| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Exceptions for specific devices. Usually work-arounds for fatal design flaws. |
| 4 | * Derived from fixup.c of i386 tree. |
| 5 | */ |
| 6 | |
| 7 | #include <linux/pci.h> |
| 8 | #include <linux/init.h> |
| 9 | #include <linux/vgaarb.h> |
| 10 | #include <linux/screen_info.h> |
| 11 | |
| 12 | #include <asm/machvec.h> |
| 13 | |
| 14 | /* |
| 15 | * Fixup to mark boot BIOS video selected by BIOS before it changes |
| 16 | * |
| 17 | * From information provided by "Jon Smirl" <jonsmirl@gmail.com> |
| 18 | * |
| 19 | * The standard boot ROM sequence for an x86 machine uses the BIOS |
| 20 | * to select an initial video card for boot display. This boot video |
| 21 | * card will have its BIOS copied to 0xC0000 in system RAM. |
| 22 | * IORESOURCE_ROM_SHADOW is used to associate the boot video |
| 23 | * card with this copy. On laptops this copy has to be used since |
| 24 | * the main ROM may be compressed or combined with another image. |
| 25 | * See pci_map_rom() for use of this flag. Before marking the device |
| 26 | * with IORESOURCE_ROM_SHADOW check if a vga_default_device is already set |
| 27 | * by either arch code or vga-arbitration; if so only apply the fixup to this |
| 28 | * already-determined primary video card. |
| 29 | */ |
| 30 | |
| 31 | static void pci_fixup_video(struct pci_dev *pdev) |
| 32 | { |
| 33 | struct pci_dev *bridge; |
| 34 | struct pci_bus *bus; |
| 35 | u16 config; |
| 36 | struct resource *res; |
| 37 | |
| 38 | if ((strcmp(ia64_platform_name, "dig") != 0) |
| 39 | && (strcmp(ia64_platform_name, "hpzx1") != 0)) |
| 40 | return; |
| 41 | /* Maybe, this machine supports legacy memory map. */ |
| 42 | |
| 43 | /* Is VGA routed to us? */ |
| 44 | bus = pdev->bus; |
| 45 | while (bus) { |
| 46 | bridge = bus->self; |
| 47 | |
| 48 | /* |
| 49 | * From information provided by |
| 50 | * "David Miller" <davem@davemloft.net> |
| 51 | * The bridge control register is valid for PCI header |
| 52 | * type BRIDGE, or CARDBUS. Host to PCI controllers use |
| 53 | * PCI header type NORMAL. |
| 54 | */ |
| 55 | if (bridge && (pci_is_bridge(bridge))) { |
| 56 | pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, |
| 57 | &config); |
| 58 | if (!(config & PCI_BRIDGE_CTL_VGA)) |
| 59 | return; |
| 60 | } |
| 61 | bus = bus->parent; |
| 62 | } |
| 63 | if (!vga_default_device() || pdev == vga_default_device()) { |
| 64 | pci_read_config_word(pdev, PCI_COMMAND, &config); |
| 65 | if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { |
| 66 | res = &pdev->resource[PCI_ROM_RESOURCE]; |
| 67 | |
| 68 | pci_disable_rom(pdev); |
| 69 | if (res->parent) |
| 70 | release_resource(res); |
| 71 | |
| 72 | res->start = 0xC0000; |
| 73 | res->end = res->start + 0x20000 - 1; |
| 74 | res->flags = IORESOURCE_MEM | IORESOURCE_ROM_SHADOW | |
| 75 | IORESOURCE_PCI_FIXED; |
| 76 | dev_info(&pdev->dev, "Video device with shadowed ROM at %pR\n", |
| 77 | res); |
| 78 | } |
| 79 | } |
| 80 | } |
| 81 | DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_ANY_ID, PCI_ANY_ID, |
| 82 | PCI_CLASS_DISPLAY_VGA, 8, pci_fixup_video); |