1// SPDX-License-Identifier: GPL-2.0 2#include <linux/sched.h> 3#include <linux/mm.h> 4#include <linux/uaccess.h> 5#include <linux/mmzone.h> 6#include <linux/ioport.h> 7#include <linux/seq_file.h> 8#include <linux/console.h> 9#include <linux/init.h> 10#include <linux/edd.h> 11#include <linux/dmi.h> 12#include <linux/pfn.h> 13#include <linux/pci.h> 14#include <linux/export.h> 15 16#include <asm/probe_roms.h> 17#include <asm/pci-direct.h> 18#include <asm/e820/api.h> 19#include <asm/mmzone.h> 20#include <asm/setup.h> 21#include <asm/sections.h> 22#include <asm/io.h> 23#include <asm/setup_arch.h> 24#include <asm/sev.h> 25 26static struct resource system_rom_resource = { 27 .name = "System ROM", 28 .start = 0xf0000, 29 .end = 0xfffff, 30 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM 31}; 32 33static struct resource extension_rom_resource = { 34 .name = "Extension ROM", 35 .start = 0xe0000, 36 .end = 0xeffff, 37 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM 38}; 39 40static struct resource adapter_rom_resources[] = { { 41 .name = "Adapter ROM", 42 .start = 0xc8000, 43 .end = 0, 44 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM 45}, { 46 .name = "Adapter ROM", 47 .start = 0, 48 .end = 0, 49 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM 50}, { 51 .name = "Adapter ROM", 52 .start = 0, 53 .end = 0, 54 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM 55}, { 56 .name = "Adapter ROM", 57 .start = 0, 58 .end = 0, 59 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM 60}, { 61 .name = "Adapter ROM", 62 .start = 0, 63 .end = 0, 64 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM 65}, { 66 .name = "Adapter ROM", 67 .start = 0, 68 .end = 0, 69 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM 70} }; 71 72static struct resource video_rom_resource = { 73 .name = "Video ROM", 74 .start = 0xc0000, 75 .end = 0xc7fff, 76 .flags = IORESOURCE_BUSY | IORESOURCE_READONLY | IORESOURCE_MEM 77}; 78 79/* does this oprom support the given pci device, or any of the devices 80 * that the driver supports? 81 */ 82static bool match_id(struct pci_dev *pdev, unsigned short vendor, unsigned short device) 83{ 84 struct pci_driver *drv = to_pci_driver(pdev->dev.driver); 85 const struct pci_device_id *id; 86 87 if (pdev->vendor == vendor && pdev->device == device) 88 return true; 89 90 for (id = drv ? drv->id_table : NULL; id && id->vendor; id++) 91 if (id->vendor == vendor && id->device == device) 92 break; 93 94 return id && id->vendor; 95} 96 97static bool probe_list(struct pci_dev *pdev, unsigned short vendor, 98 const void *rom_list) 99{ 100 unsigned short device; 101 102 do { 103 if (get_kernel_nofault(device, rom_list) != 0) 104 device = 0; 105 106 if (device && match_id(pdev, vendor, device)) 107 break; 108 109 rom_list += 2; 110 } while (device); 111 112 return !!device; 113} 114 115static struct resource *find_oprom(struct pci_dev *pdev) 116{ 117 struct resource *oprom = NULL; 118 int i; 119 120 for (i = 0; i < ARRAY_SIZE(adapter_rom_resources); i++) { 121 struct resource *res = &adapter_rom_resources[i]; 122 unsigned short offset, vendor, device, list, rev; 123 const void *rom; 124 125 if (res->end == 0) 126 break; 127 128 rom = isa_bus_to_virt(res->start); 129 if (get_kernel_nofault(offset, rom + 0x18) != 0) 130 continue; 131 132 if (get_kernel_nofault(vendor, rom + offset + 0x4) != 0) 133 continue; 134 135 if (get_kernel_nofault(device, rom + offset + 0x6) != 0) 136 continue; 137 138 if (match_id(pdev, vendor, device)) { 139 oprom = res; 140 break; 141 } 142 143 if (get_kernel_nofault(list, rom + offset + 0x8) == 0 && 144 get_kernel_nofault(rev, rom + offset + 0xc) == 0 && 145 rev >= 3 && list && 146 probe_list(pdev, vendor, rom + offset + list)) { 147 oprom = res; 148 break; 149 } 150 } 151 152 return oprom; 153} 154 155void __iomem *pci_map_biosrom(struct pci_dev *pdev) 156{ 157 struct resource *oprom = find_oprom(pdev); 158 159 if (!oprom) 160 return NULL; 161 162 return ioremap(oprom->start, resource_size(oprom)); 163} 164EXPORT_SYMBOL(pci_map_biosrom); 165 166void pci_unmap_biosrom(void __iomem *image) 167{ 168 iounmap(image); 169} 170EXPORT_SYMBOL(pci_unmap_biosrom); 171 172size_t pci_biosrom_size(struct pci_dev *pdev) 173{ 174 struct resource *oprom = find_oprom(pdev); 175 176 return oprom ? resource_size(oprom) : 0; 177} 178EXPORT_SYMBOL(pci_biosrom_size); 179 180#define ROMSIGNATURE 0xaa55 181 182static int __init romsignature(const unsigned char *rom) 183{ 184 const unsigned short * const ptr = (const unsigned short *)rom; 185 unsigned short sig; 186 187 return get_kernel_nofault(sig, ptr) == 0 && sig == ROMSIGNATURE; 188} 189 190static int __init romchecksum(const unsigned char *rom, unsigned long length) 191{ 192 unsigned char sum, c; 193 194 for (sum = 0; length && get_kernel_nofault(c, rom++) == 0; length--) 195 sum += c; 196 return !length && !sum; 197} 198 199void __init probe_roms(void) 200{ 201 unsigned long start, length, upper; 202 const unsigned char *rom; 203 unsigned char c; 204 int i; 205 206 /* video rom */ 207 upper = adapter_rom_resources[0].start; 208 for (start = video_rom_resource.start; start < upper; start += 2048) { 209 rom = isa_bus_to_virt(start); 210 if (!romsignature(rom)) 211 continue; 212 213 video_rom_resource.start = start; 214 215 if (get_kernel_nofault(c, rom + 2) != 0) 216 continue; 217 218 /* 0 < length <= 0x7f * 512, historically */ 219 length = c * 512; 220 221 /* if checksum okay, trust length byte */ 222 if (length && romchecksum(rom, length)) 223 video_rom_resource.end = start + length - 1; 224 225 request_resource(&iomem_resource, &video_rom_resource); 226 break; 227 } 228 229 start = (video_rom_resource.end + 1 + 2047) & ~2047UL; 230 if (start < upper) 231 start = upper; 232 233 /* system rom */ 234 request_resource(&iomem_resource, &system_rom_resource); 235 upper = system_rom_resource.start; 236 237 /* check for extension rom (ignore length byte!) */ 238 rom = isa_bus_to_virt(extension_rom_resource.start); 239 if (romsignature(rom)) { 240 length = resource_size(&extension_rom_resource); 241 if (romchecksum(rom, length)) { 242 request_resource(&iomem_resource, &extension_rom_resource); 243 upper = extension_rom_resource.start; 244 } 245 } 246 247 /* check for adapter roms on 2k boundaries */ 248 for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) { 249 rom = isa_bus_to_virt(start); 250 if (!romsignature(rom)) 251 continue; 252 253 if (get_kernel_nofault(c, rom + 2) != 0) 254 continue; 255 256 /* 0 < length <= 0x7f * 512, historically */ 257 length = c * 512; 258 259 /* but accept any length that fits if checksum okay */ 260 if (!length || start + length > upper || !romchecksum(rom, length)) 261 continue; 262 263 adapter_rom_resources[i].start = start; 264 adapter_rom_resources[i].end = start + length - 1; 265 request_resource(&iomem_resource, &adapter_rom_resources[i]); 266 267 start = adapter_rom_resources[i++].end & ~2047UL; 268 } 269} 270 271