diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/probe_roms.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/arch/x86/kernel/probe_roms.c b/arch/x86/kernel/probe_roms.c new file mode 100644 index 000000000..ee0286390 --- /dev/null +++ b/arch/x86/kernel/probe_roms.c @@ -0,0 +1,269 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/uaccess.h> +#include <linux/mmzone.h> +#include <linux/ioport.h> +#include <linux/seq_file.h> +#include <linux/console.h> +#include <linux/init.h> +#include <linux/edd.h> +#include <linux/dmi.h> +#include <linux/pfn.h> +#include <linux/pci.h> +#include <linux/export.h> + +#include <asm/probe_roms.h> +#include <asm/pci-direct.h> +#include <asm/e820/api.h> +#include <asm/mmzone.h> +#include <asm/setup.h> +#include <asm/sections.h> +#include <asm/io.h> +#include <asm/setup_arch.h> + +static struct resource system_rom_resource = { + .name = "System ROM", + .start = 0xf0000, + .end = 0xfffff, + .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM +}; + +static struct resource extension_rom_resource = { + .name = "Extension ROM", + .start = 0xe0000, + .end = 0xeffff, + .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM +}; + +static struct resource adapter_rom_resources[] = { { + .name = "Adapter ROM", + .start = 0xc8000, + .end = 0, + .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM +}, { + .name = "Adapter ROM", + .start = 0, + .end = 0, + .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM +}, { + .name = "Adapter ROM", + .start = 0, + .end = 0, + .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM +}, { + .name = "Adapter ROM", + .start = 0, + .end = 0, + .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM +}, { + .name = "Adapter ROM", + .start = 0, + .end = 0, + .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM +}, { + .name = "Adapter ROM", + .start = 0, + .end = 0, + .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM +} }; + +static struct resource video_rom_resource = { + .name = "Video ROM", + .start = 0xc0000, + .end = 0xc7fff, + .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM +}; + +/* does this oprom support the given pci device, or any of the devices + * that the driver supports? + */ +static bool match_id(struct pci_dev *pdev, unsigned short vendor, unsigned short device) +{ + struct pci_driver *drv = pdev->driver; + const struct pci_device_id *id; + + if (pdev->vendor == vendor && pdev->device == device) + return true; + + for (id = drv ? drv->id_table : NULL; id && id->vendor; id++) + if (id->vendor == vendor && id->device == device) + break; + + return id && id->vendor; +} + +static bool probe_list(struct pci_dev *pdev, unsigned short vendor, + const unsigned char *rom_list) +{ + unsigned short device; + + do { + if (probe_kernel_address(rom_list, device) != 0) + device = 0; + + if (device && match_id(pdev, vendor, device)) + break; + + rom_list += 2; + } while (device); + + return !!device; +} + +static struct resource *find_oprom(struct pci_dev *pdev) +{ + struct resource *oprom = NULL; + int i; + + for (i = 0; i < ARRAY_SIZE(adapter_rom_resources); i++) { + struct resource *res = &adapter_rom_resources[i]; + unsigned short offset, vendor, device, list, rev; + const unsigned char *rom; + + if (res->end == 0) + break; + + rom = isa_bus_to_virt(res->start); + if (probe_kernel_address(rom + 0x18, offset) != 0) + continue; + + if (probe_kernel_address(rom + offset + 0x4, vendor) != 0) + continue; + + if (probe_kernel_address(rom + offset + 0x6, device) != 0) + continue; + + if (match_id(pdev, vendor, device)) { + oprom = res; + break; + } + + if (probe_kernel_address(rom + offset + 0x8, list) == 0 && + probe_kernel_address(rom + offset + 0xc, rev) == 0 && + rev >= 3 && list && + probe_list(pdev, vendor, rom + offset + list)) { + oprom = res; + break; + } + } + + return oprom; +} + +void __iomem *pci_map_biosrom(struct pci_dev *pdev) +{ + struct resource *oprom = find_oprom(pdev); + + if (!oprom) + return NULL; + + return ioremap(oprom->start, resource_size(oprom)); +} +EXPORT_SYMBOL(pci_map_biosrom); + +void pci_unmap_biosrom(void __iomem *image) +{ + iounmap(image); +} +EXPORT_SYMBOL(pci_unmap_biosrom); + +size_t pci_biosrom_size(struct pci_dev *pdev) +{ + struct resource *oprom = find_oprom(pdev); + + return oprom ? resource_size(oprom) : 0; +} +EXPORT_SYMBOL(pci_biosrom_size); + +#define ROMSIGNATURE 0xaa55 + +static int __init romsignature(const unsigned char *rom) +{ + const unsigned short * const ptr = (const unsigned short *)rom; + unsigned short sig; + + return probe_kernel_address(ptr, sig) == 0 && sig == ROMSIGNATURE; +} + +static int __init romchecksum(const unsigned char *rom, unsigned long length) +{ + unsigned char sum, c; + + for (sum = 0; length && probe_kernel_address(rom++, c) == 0; length--) + sum += c; + return !length && !sum; +} + +void __init probe_roms(void) +{ + const unsigned char *rom; + unsigned long start, length, upper; + unsigned char c; + int i; + + /* video rom */ + upper = adapter_rom_resources[0].start; + for (start = video_rom_resource.start; start < upper; start += 2048) { + rom = isa_bus_to_virt(start); + if (!romsignature(rom)) + continue; + + video_rom_resource.start = start; + + if (probe_kernel_address(rom + 2, c) != 0) + continue; + + /* 0 < length <= 0x7f * 512, historically */ + length = c * 512; + + /* if checksum okay, trust length byte */ + if (length && romchecksum(rom, length)) + video_rom_resource.end = start + length - 1; + + request_resource(&iomem_resource, &video_rom_resource); + break; + } + + start = (video_rom_resource.end + 1 + 2047) & ~2047UL; + if (start < upper) + start = upper; + + /* system rom */ + request_resource(&iomem_resource, &system_rom_resource); + upper = system_rom_resource.start; + + /* check for extension rom (ignore length byte!) */ + rom = isa_bus_to_virt(extension_rom_resource.start); + if (romsignature(rom)) { + length = resource_size(&extension_rom_resource); + if (romchecksum(rom, length)) { + request_resource(&iomem_resource, &extension_rom_resource); + upper = extension_rom_resource.start; + } + } + + /* check for adapter roms on 2k boundaries */ + for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) { + rom = isa_bus_to_virt(start); + if (!romsignature(rom)) + continue; + + if (probe_kernel_address(rom + 2, c) != 0) + continue; + + /* 0 < length <= 0x7f * 512, historically */ + length = c * 512; + + /* but accept any length that fits if checksum okay */ + if (!length || start + length > upper || !romchecksum(rom, length)) + continue; + + adapter_rom_resources[i].start = start; + adapter_rom_resources[i].end = start + length - 1; + request_resource(&iomem_resource, &adapter_rom_resources[i]); + + start = adapter_rom_resources[i++].end & ~2047UL; + } +} + |