diff options
Diffstat (limited to 'arch/ia64/pci/fixup.c')
| -rw-r--r-- | arch/ia64/pci/fixup.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/arch/ia64/pci/fixup.c b/arch/ia64/pci/fixup.c new file mode 100644 index 000000000..acb55a412 --- /dev/null +++ b/arch/ia64/pci/fixup.c @@ -0,0 +1,80 @@ +// 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/uv/uv.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 (is_uv_system()) + 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); |