1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * FDT related Helper functions used by the EFI stub on multiple 4 * architectures. This should be #included by the EFI stub 5 * implementation files. 6 * 7 * Copyright 2013 Linaro Limited; author Roy Franz 8 */ 9 10 #include <linux/efi.h> 11 #include <linux/libfdt.h> 12 #include <asm/efi.h> 13 14 #include "efistub.h" 15 16 #define EFI_DT_ADDR_CELLS_DEFAULT 2 17 #define EFI_DT_SIZE_CELLS_DEFAULT 2 18 19 static void fdt_update_cell_size(efi_system_table_t *sys_table, void *fdt) 20 { 21 int offset; 22 23 offset = fdt_path_offset(fdt, "/"); 24 /* Set the #address-cells and #size-cells values for an empty tree */ 25 26 fdt_setprop_u32(fdt, offset, "#address-cells", EFI_DT_ADDR_CELLS_DEFAULT); 27 fdt_setprop_u32(fdt, offset, "#size-cells", EFI_DT_SIZE_CELLS_DEFAULT); 28 } 29 30 static efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, 31 unsigned long orig_fdt_size, 32 void *fdt, int new_fdt_size, char *cmdline_ptr, 33 u64 initrd_addr, u64 initrd_size) 34 { 35 int node, num_rsv; 36 int status; 37 u32 fdt_val32; 38 u64 fdt_val64; 39 40 /* Do some checks on provided FDT, if it exists: */ 41 if (orig_fdt) { 42 if (fdt_check_header(orig_fdt)) { 43 pr_efi_err(sys_table, "Device Tree header not valid!\n"); 44 return EFI_LOAD_ERROR; 45 } 46 /* 47 * We don't get the size of the FDT if we get if from a 48 * configuration table: 49 */ 50 if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) { 51 pr_efi_err(sys_table, "Truncated device tree! foo!\n"); 52 return EFI_LOAD_ERROR; 53 } 54 } 55 56 if (orig_fdt) { 57 status = fdt_open_into(orig_fdt, fdt, new_fdt_size); 58 } else { 59 status = fdt_create_empty_tree(fdt, new_fdt_size); 60 if (status == 0) { 61 /* 62 * Any failure from the following function is 63 * non-critical: 64 */ 65 fdt_update_cell_size(sys_table, fdt); 66 } 67 } 68 69 if (status != 0) 70 goto fdt_set_fail; 71 72 /* 73 * Delete all memory reserve map entries. When booting via UEFI, 74 * kernel will use the UEFI memory map to find reserved regions. 75 */ 76 num_rsv = fdt_num_mem_rsv(fdt); 77 while (num_rsv-- > 0) 78 fdt_del_mem_rsv(fdt, num_rsv); 79 80 node = fdt_subnode_offset(fdt, 0, "chosen"); 81 if (node < 0) { 82 node = fdt_add_subnode(fdt, 0, "chosen"); 83 if (node < 0) { 84 /* 'node' is an error code when negative: */ 85 status = node; 86 goto fdt_set_fail; 87 } 88 } 89 90 if (cmdline_ptr != NULL && strlen(cmdline_ptr) > 0) { 91 status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr, 92 strlen(cmdline_ptr) + 1); 93 if (status) 94 goto fdt_set_fail; 95 } 96 97 /* Set initrd address/end in device tree, if present */ 98 if (initrd_size != 0) { 99 u64 initrd_image_end; 100 u64 initrd_image_start = cpu_to_fdt64(initrd_addr); 101 102 status = fdt_setprop_var(fdt, node, "linux,initrd-start", initrd_image_start); 103 if (status) 104 goto fdt_set_fail; 105 106 initrd_image_end = cpu_to_fdt64(initrd_addr + initrd_size); 107 status = fdt_setprop_var(fdt, node, "linux,initrd-end", initrd_image_end); 108 if (status) 109 goto fdt_set_fail; 110 } 111 112 /* Add FDT entries for EFI runtime services in chosen node. */ 113 node = fdt_subnode_offset(fdt, 0, "chosen"); 114 fdt_val64 = cpu_to_fdt64((u64)(unsigned long)sys_table); 115 116 status = fdt_setprop_var(fdt, node, "linux,uefi-system-table", fdt_val64); 117 if (status) 118 goto fdt_set_fail; 119 120 fdt_val64 = U64_MAX; /* placeholder */ 121 122 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-start", fdt_val64); 123 if (status) 124 goto fdt_set_fail; 125 126 fdt_val32 = U32_MAX; /* placeholder */ 127 128 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-size", fdt_val32); 129 if (status) 130 goto fdt_set_fail; 131 132 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32); 133 if (status) 134 goto fdt_set_fail; 135 136 status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-ver", fdt_val32); 137 if (status) 138 goto fdt_set_fail; 139 140 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { 141 efi_status_t efi_status; 142 143 efi_status = efi_get_random_bytes(sys_table, sizeof(fdt_val64), 144 (u8 *)&fdt_val64); 145 if (efi_status == EFI_SUCCESS) { 146 status = fdt_setprop_var(fdt, node, "kaslr-seed", fdt_val64); 147 if (status) 148 goto fdt_set_fail; 149 } else if (efi_status != EFI_NOT_FOUND) { 150 return efi_status; 151 } 152 } 153 154 /* Shrink the FDT back to its minimum size: */ 155 fdt_pack(fdt); 156 157 return EFI_SUCCESS; 158 159 fdt_set_fail: 160 if (status == -FDT_ERR_NOSPACE) 161 return EFI_BUFFER_TOO_SMALL; 162 163 return EFI_LOAD_ERROR; 164 } 165 166 static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map) 167 { 168 int node = fdt_path_offset(fdt, "/chosen"); 169 u64 fdt_val64; 170 u32 fdt_val32; 171 int err; 172 173 if (node < 0) 174 return EFI_LOAD_ERROR; 175 176 fdt_val64 = cpu_to_fdt64((unsigned long)*map->map); 177 178 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-start", fdt_val64); 179 if (err) 180 return EFI_LOAD_ERROR; 181 182 fdt_val32 = cpu_to_fdt32(*map->map_size); 183 184 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-size", fdt_val32); 185 if (err) 186 return EFI_LOAD_ERROR; 187 188 fdt_val32 = cpu_to_fdt32(*map->desc_size); 189 190 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32); 191 if (err) 192 return EFI_LOAD_ERROR; 193 194 fdt_val32 = cpu_to_fdt32(*map->desc_ver); 195 196 err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-ver", fdt_val32); 197 if (err) 198 return EFI_LOAD_ERROR; 199 200 return EFI_SUCCESS; 201 } 202 203 #ifndef EFI_FDT_ALIGN 204 # define EFI_FDT_ALIGN EFI_PAGE_SIZE 205 #endif 206 207 struct exit_boot_struct { 208 efi_memory_desc_t *runtime_map; 209 int *runtime_entry_count; 210 void *new_fdt_addr; 211 }; 212 213 static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg, 214 struct efi_boot_memmap *map, 215 void *priv) 216 { 217 struct exit_boot_struct *p = priv; 218 /* 219 * Update the memory map with virtual addresses. The function will also 220 * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME 221 * entries so that we can pass it straight to SetVirtualAddressMap() 222 */ 223 efi_get_virtmap(*map->map, *map->map_size, *map->desc_size, 224 p->runtime_map, p->runtime_entry_count); 225 226 return update_fdt_memmap(p->new_fdt_addr, map); 227 } 228 229 #ifndef MAX_FDT_SIZE 230 # define MAX_FDT_SIZE SZ_2M 231 #endif 232 233 /* 234 * Allocate memory for a new FDT, then add EFI, commandline, and 235 * initrd related fields to the FDT. This routine increases the 236 * FDT allocation size until the allocated memory is large 237 * enough. EFI allocations are in EFI_PAGE_SIZE granules, 238 * which are fixed at 4K bytes, so in most cases the first 239 * allocation should succeed. 240 * EFI boot services are exited at the end of this function. 241 * There must be no allocations between the get_memory_map() 242 * call and the exit_boot_services() call, so the exiting of 243 * boot services is very tightly tied to the creation of the FDT 244 * with the final memory map in it. 245 */ 246 247 efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, 248 void *handle, 249 unsigned long *new_fdt_addr, 250 unsigned long max_addr, 251 u64 initrd_addr, u64 initrd_size, 252 char *cmdline_ptr, 253 unsigned long fdt_addr, 254 unsigned long fdt_size) 255 { 256 unsigned long map_size, desc_size, buff_size; 257 u32 desc_ver; 258 unsigned long mmap_key; 259 efi_memory_desc_t *memory_map, *runtime_map; 260 efi_status_t status; 261 int runtime_entry_count; 262 struct efi_boot_memmap map; 263 struct exit_boot_struct priv; 264 265 map.map = &runtime_map; 266 map.map_size = &map_size; 267 map.desc_size = &desc_size; 268 map.desc_ver = &desc_ver; 269 map.key_ptr = &mmap_key; 270 map.buff_size = &buff_size; 271 272 /* 273 * Get a copy of the current memory map that we will use to prepare 274 * the input for SetVirtualAddressMap(). We don't have to worry about 275 * subsequent allocations adding entries, since they could not affect 276 * the number of EFI_MEMORY_RUNTIME regions. 277 */ 278 status = efi_get_memory_map(sys_table, &map); 279 if (status != EFI_SUCCESS) { 280 pr_efi_err(sys_table, "Unable to retrieve UEFI memory map.\n"); 281 return status; 282 } 283 284 pr_efi(sys_table, "Exiting boot services and installing virtual address map...\n"); 285 286 map.map = &memory_map; 287 status = efi_high_alloc(sys_table, MAX_FDT_SIZE, EFI_FDT_ALIGN, 288 new_fdt_addr, max_addr); 289 if (status != EFI_SUCCESS) { 290 pr_efi_err(sys_table, "Unable to allocate memory for new device tree.\n"); 291 goto fail; 292 } 293 294 /* 295 * Now that we have done our final memory allocation (and free) 296 * we can get the memory map key needed for exit_boot_services(). 297 */ 298 status = efi_get_memory_map(sys_table, &map); 299 if (status != EFI_SUCCESS) 300 goto fail_free_new_fdt; 301 302 status = update_fdt(sys_table, (void *)fdt_addr, fdt_size, 303 (void *)*new_fdt_addr, MAX_FDT_SIZE, cmdline_ptr, 304 initrd_addr, initrd_size); 305 306 if (status != EFI_SUCCESS) { 307 pr_efi_err(sys_table, "Unable to construct new device tree.\n"); 308 goto fail_free_new_fdt; 309 } 310 311 runtime_entry_count = 0; 312 priv.runtime_map = runtime_map; 313 priv.runtime_entry_count = &runtime_entry_count; 314 priv.new_fdt_addr = (void *)*new_fdt_addr; 315 316 status = efi_exit_boot_services(sys_table, handle, &map, &priv, exit_boot_func); 317 318 if (status == EFI_SUCCESS) { 319 efi_set_virtual_address_map_t *svam; 320 321 if (novamap()) 322 return EFI_SUCCESS; 323 324 /* Install the new virtual address map */ 325 svam = sys_table->runtime->set_virtual_address_map; 326 status = svam(runtime_entry_count * desc_size, desc_size, 327 desc_ver, runtime_map); 328 329 /* 330 * We are beyond the point of no return here, so if the call to 331 * SetVirtualAddressMap() failed, we need to signal that to the 332 * incoming kernel but proceed normally otherwise. 333 */ 334 if (status != EFI_SUCCESS) { 335 int l; 336 337 /* 338 * Set the virtual address field of all 339 * EFI_MEMORY_RUNTIME entries to 0. This will signal 340 * the incoming kernel that no virtual translation has 341 * been installed. 342 */ 343 for (l = 0; l < map_size; l += desc_size) { 344 efi_memory_desc_t *p = (void *)memory_map + l; 345 346 if (p->attribute & EFI_MEMORY_RUNTIME) 347 p->virt_addr = 0; 348 } 349 } 350 return EFI_SUCCESS; 351 } 352 353 pr_efi_err(sys_table, "Exit boot services failed.\n"); 354 355 fail_free_new_fdt: 356 efi_free(sys_table, MAX_FDT_SIZE, *new_fdt_addr); 357 358 fail: 359 sys_table->boottime->free_pool(runtime_map); 360 361 return EFI_LOAD_ERROR; 362 } 363 364 void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size) 365 { 366 efi_guid_t fdt_guid = DEVICE_TREE_GUID; 367 efi_config_table_t *tables; 368 int i; 369 370 tables = (efi_config_table_t *)sys_table->tables; 371 372 for (i = 0; i < sys_table->nr_tables; i++) { 373 void *fdt; 374 375 if (efi_guidcmp(tables[i].guid, fdt_guid) != 0) 376 continue; 377 378 fdt = (void *)tables[i].table; 379 if (fdt_check_header(fdt) != 0) { 380 pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n"); 381 return NULL; 382 } 383 *fdt_size = fdt_totalsize(fdt); 384 return fdt; 385 } 386 387 return NULL; 388 } 389