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 26 static 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 33 static 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 40 static 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 72 static 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 */ 82 static 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 97 static 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 } 114 115 static 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 } 154 155 void __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 } 164 EXPORT_SYMBOL(pci_map_biosrom); 165 166 void pci_unmap_biosrom(void __iomem *image) 167 { 168 iounmap(image); 169 } 170 EXPORT_SYMBOL(pci_unmap_biosrom); 171 172 size_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 } 178 EXPORT_SYMBOL(pci_biosrom_size); 179 180 #define ROMSIGNATURE 0xaa55 181 182 static 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 } 189 190 static 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 } 198 199 void __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 /* 207 * The ROM memory range is not part of the e820 table and is therefore not 208 * pre-validated by BIOS. The kernel page table maps the ROM region as encrypted 209 * memory, and SNP requires encrypted memory to be validated before access. 210 * Do that here. 211 */ 212 snp_prep_memory(video_rom_resource.start, 213 ((system_rom_resource.end + 1) - video_rom_resource.start), 214 SNP_PAGE_STATE_PRIVATE); 215 216 /* video rom */ 217 upper = adapter_rom_resources[0].start; 218 for (start = video_rom_resource.start; start < upper; start += 2048) { 219 rom = isa_bus_to_virt(start); 220 if (!romsignature(rom)) 221 continue; 222 223 video_rom_resource.start = start; 224 225 if (get_kernel_nofault(c, rom + 2) != 0) 226 continue; 227 228 /* 0 < length <= 0x7f * 512, historically */ 229 length = c * 512; 230 231 /* if checksum okay, trust length byte */ 232 if (length && romchecksum(rom, length)) 233 video_rom_resource.end = start + length - 1; 234 235 request_resource(&iomem_resource, &video_rom_resource); 236 break; 237 } 238 239 start = (video_rom_resource.end + 1 + 2047) & ~2047UL; 240 if (start < upper) 241 start = upper; 242 243 /* system rom */ 244 request_resource(&iomem_resource, &system_rom_resource); 245 upper = system_rom_resource.start; 246 247 /* check for extension rom (ignore length byte!) */ 248 rom = isa_bus_to_virt(extension_rom_resource.start); 249 if (romsignature(rom)) { 250 length = resource_size(&extension_rom_resource); 251 if (romchecksum(rom, length)) { 252 request_resource(&iomem_resource, &extension_rom_resource); 253 upper = extension_rom_resource.start; 254 } 255 } 256 257 /* check for adapter roms on 2k boundaries */ 258 for (i = 0; i < ARRAY_SIZE(adapter_rom_resources) && start < upper; start += 2048) { 259 rom = isa_bus_to_virt(start); 260 if (!romsignature(rom)) 261 continue; 262 263 if (get_kernel_nofault(c, rom + 2) != 0) 264 continue; 265 266 /* 0 < length <= 0x7f * 512, historically */ 267 length = c * 512; 268 269 /* but accept any length that fits if checksum okay */ 270 if (!length || start + length > upper || !romchecksum(rom, length)) 271 continue; 272 273 adapter_rom_resources[i].start = start; 274 adapter_rom_resources[i].end = start + length - 1; 275 request_resource(&iomem_resource, &adapter_rom_resources[i]); 276 277 start = adapter_rom_resources[i++].end & ~2047UL; 278 } 279 } 280 281