arch/arm/cpu/armv8/sec_firmware.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright 2016 NXP Semiconductor, Inc.
   4  */
   5
   6 #include <common.h>
   7 #include <cpu_func.h>
   8 #include <errno.h>
   9 #include <linux/kernel.h>
  10 #include <asm/io.h>
  11 #include <asm/system.h>
  12 #include <asm/types.h>
  13 #include <asm/macro.h>
  14 #include <asm/armv8/sec_firmware.h>
  15
  16 DECLARE_GLOBAL_DATA_PTR;
  17 extern void c_runtime_cpu_setup(void);
  18
  19 #define SEC_FIRMWARE_LOADED     0x1
  20 #define SEC_FIRMWARE_RUNNING    0x2
  21 #define SEC_FIRMWARE_ADDR_MASK  (~0x3)
  22 /*
  23  * Secure firmware load addr
  24  * Flags used: 0x1 secure firmware has been loaded to secure memory
  25  *             0x2 secure firmware is running
  26  */
  27 phys_addr_t sec_firmware_addr;
  28
  29 #ifndef SEC_FIRMWARE_FIT_IMAGE
  30 #define SEC_FIRMWARE_FIT_IMAGE          "firmware"
  31 #endif
  32 #ifndef SEC_FIRMEWARE_FIT_CNF_NAME
  33 #define SEC_FIRMEWARE_FIT_CNF_NAME      "config-1"
  34 #endif
  35 #ifndef SEC_FIRMWARE_TARGET_EL
  36 #define SEC_FIRMWARE_TARGET_EL          2
  37 #endif
  38
  39 static int sec_firmware_get_data(const void *sec_firmware_img,
  40                                 const void **data, size_t *size)
  41 {
  42         int conf_node_off, fw_node_off;
  43         char *conf_node_name = NULL;
  44         char *desc;
  45         int ret;
  46
  47         conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;
  48
  49         conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
  50         if (conf_node_off < 0) {
  51                 printf("SEC Firmware: %s: no such config\n", conf_node_name);
  52                 return -ENOENT;
  53         }
  54
  55         fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
  56                         SEC_FIRMWARE_FIT_IMAGE);
  57         if (fw_node_off < 0) {
  58                 printf("SEC Firmware: No '%s' in config\n",
  59                        SEC_FIRMWARE_FIT_IMAGE);
  60                 return -ENOLINK;
  61         }
  62
  63         /* Verify secure firmware image */
  64         if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
  65                 printf("SEC Firmware: Bad firmware image (bad CRC)\n");
  66                 return -EINVAL;
  67         }
  68
  69         if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
  70                 printf("SEC Firmware: Can't get %s subimage data/size",
  71                        SEC_FIRMWARE_FIT_IMAGE);
  72                 return -ENOENT;
  73         }
  74
  75         ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
  76         if (ret)
  77                 printf("SEC Firmware: Can't get description\n");
  78         else
  79                 printf("%s\n", desc);
  80
  81         return ret;
  82 }
  83
  84 /*
  85  * SEC Firmware FIT image parser checks if the image is in FIT
  86  * format, verifies integrity of the image and calculates raw
  87  * image address and size values.
  88  *
  89  * Returns 0 on success and a negative errno on error task fail.
  90  */
  91 static int sec_firmware_parse_image(const void *sec_firmware_img,
  92                                         const void **raw_image_addr,
  93                                         size_t *raw_image_size)
  94 {
  95         int ret;
  96
  97         ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
  98                                         raw_image_size);
  99         if (ret)
 100                 return ret;
 101
 102         debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
 103               *raw_image_addr, *raw_image_size);
 104
 105         return 0;
 106 }
 107
 108 /*
 109  * SEC Firmware FIT image parser to check if any loadable is
 110  * present. If present, verify integrity of the loadable and
 111  * copy loadable to address provided in (loadable_h, loadable_l).
 112  *
 113  * Returns 0 on success and a negative errno on error task fail.
 114  */
 115 static int sec_firmware_check_copy_loadable(const void *sec_firmware_img,
 116                                             u32 *loadable_l, u32 *loadable_h)
 117 {
 118         phys_addr_t sec_firmware_loadable_addr = 0;
 119         int conf_node_off, ld_node_off, images;
 120         char *conf_node_name = NULL;
 121         const void *data;
 122         size_t size;
 123         ulong load;
 124         const char *name, *str, *type;
 125         int len;
 126
 127         conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;
 128
 129         conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
 130         if (conf_node_off < 0) {
 131                 printf("SEC Firmware: %s: no such config\n", conf_node_name);
 132                 return -ENOENT;
 133         }
 134
 135         /* find the node holding the images information */
 136         images = fdt_path_offset(sec_firmware_img, FIT_IMAGES_PATH);
 137         if (images < 0) {
 138                 printf("%s: Cannot find /images node: %d\n", __func__, images);
 139                 return -1;
 140         }
 141
 142         type = FIT_LOADABLE_PROP;
 143
 144         name = fdt_getprop(sec_firmware_img, conf_node_off, type, &len);
 145         if (!name) {
 146                 /* Loadables not present */
 147                 return 0;
 148         }
 149
 150         printf("SEC Firmware: '%s' present in config\n", type);
 151
 152         for (str = name; str && ((str - name) < len);
 153              str = strchr(str, '\0') + 1) {
 154                 printf("%s: '%s'\n", type, str);
 155                 ld_node_off = fdt_subnode_offset(sec_firmware_img, images, str);
 156                 if (ld_node_off < 0) {
 157                         printf("cannot find image node '%s': %d\n", str,
 158                                ld_node_off);
 159                         return -EINVAL;
 160                 }
 161
 162                 /* Verify secure firmware image */
 163                 if (!(fit_image_verify(sec_firmware_img, ld_node_off))) {
 164                         printf("SEC Loadable: Bad loadable image (bad CRC)\n");
 165                         return -EINVAL;
 166                 }
 167
 168                 if (fit_image_get_data(sec_firmware_img, ld_node_off,
 169                                        &data, &size)) {
 170                         printf("SEC Loadable: Can't get subimage data/size");
 171                         return -ENOENT;
 172                 }
 173
 174                 /* Get load address, treated as load offset to secure memory */
 175                 if (fit_image_get_load(sec_firmware_img, ld_node_off, &load)) {
 176                         printf("SEC Loadable: Can't get subimage load");
 177                         return -ENOENT;
 178                 }
 179
 180                 /* Compute load address for loadable in secure memory */
 181                 sec_firmware_loadable_addr = (sec_firmware_addr -
 182                                                 gd->arch.tlb_size) + load;
 183
 184                 /* Copy loadable to secure memory and flush dcache */
 185                 debug("%s copied to address 0x%p\n",
 186                       FIT_LOADABLE_PROP, (void *)sec_firmware_loadable_addr);
 187                 memcpy((void *)sec_firmware_loadable_addr, data, size);
 188                 flush_dcache_range(sec_firmware_loadable_addr,
 189                                    sec_firmware_loadable_addr + size);
 190
 191                 /* Populate loadable address only for Trusted OS */
 192                 if (!strcmp(str, "trustedOS@1")) {
 193                         /*
 194                          * Populate address ptrs for loadable image with
 195                          * loadbale addr
 196                          */
 197                         out_le32(loadable_l, (sec_firmware_loadable_addr &
 198                                               WORD_MASK));
 199                         out_le32(loadable_h, (sec_firmware_loadable_addr >>
 200                                               WORD_SHIFT));
 201                 }
 202         }
 203
 204         return 0;
 205 }
 206
 207 static int sec_firmware_copy_image(const char *title,
 208                          u64 image_addr, u32 image_size, u64 sec_firmware)
 209 {
 210         debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
 211         memcpy((void *)sec_firmware, (void *)image_addr, image_size);
 212         flush_dcache_range(sec_firmware, sec_firmware + image_size);
 213
 214         return 0;
 215 }
 216
 217 /*
 218  * This function will parse the SEC Firmware image, and then load it
 219  * to secure memory. Also load any loadable if present along with SEC
 220  * Firmware image.
 221  */
 222 static int sec_firmware_load_image(const void *sec_firmware_img,
 223                                    u32 *loadable_l, u32 *loadable_h)
 224 {
 225         const void *raw_image_addr;
 226         size_t raw_image_size = 0;
 227         int ret;
 228
 229         /*
 230          * The Excetpion Level must be EL3 to load and initialize
 231          * the SEC Firmware.
 232          */
 233         if (current_el() != 3) {
 234                 ret = -EACCES;
 235                 goto out;
 236         }
 237
 238 #ifdef CONFIG_SYS_MEM_RESERVE_SECURE
 239         /*
 240          * The SEC Firmware must be stored in secure memory.
 241          * Append SEC Firmware to secure mmu table.
 242          */
 243         if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
 244                 ret = -ENXIO;
 245                 goto out;
 246         }
 247
 248         sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
 249                         gd->arch.tlb_size;
 250 #else
 251 #error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
 252 #endif
 253
 254         /* Align SEC Firmware base address to 4K */
 255         sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
 256         debug("SEC Firmware: Load address: 0x%llx\n",
 257               sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
 258
 259         ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
 260                         &raw_image_size);
 261         if (ret)
 262                 goto out;
 263
 264         /* TODO:
 265          * Check if the end addr of SEC Firmware has been extend the secure
 266          * memory.
 267          */
 268
 269         /* Copy the secure firmware to secure memory */
 270         ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
 271                         raw_image_size, sec_firmware_addr &
 272                         SEC_FIRMWARE_ADDR_MASK);
 273         if (ret)
 274                 goto out;
 275
 276         /*
 277          * Check if any loadable are present along with firmware image, if
 278          * present load them.
 279          */
 280         ret = sec_firmware_check_copy_loadable(sec_firmware_img, loadable_l,
 281                                                loadable_h);
 282         if (ret)
 283                 goto out;
 284
 285         sec_firmware_addr |= SEC_FIRMWARE_LOADED;
 286         debug("SEC Firmware: Entry point: 0x%llx\n",
 287               sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
 288
 289         return 0;
 290
 291 out:
 292         printf("SEC Firmware: error (%d)\n", ret);
 293         sec_firmware_addr = 0;
 294
 295         return ret;
 296 }
 297
 298 static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
 299 {
 300         const void *entry = (void *)(sec_firmware_addr &
 301                                 SEC_FIRMWARE_ADDR_MASK);
 302
 303         return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
 304 }
 305
 306 /* Check the secure firmware FIT image */
 307 __weak bool sec_firmware_is_valid(const void *sec_firmware_img)
 308 {
 309         if (fdt_check_header(sec_firmware_img)) {
 310                 printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
 311                 return false;
 312         }
 313
 314         if (!fit_check_format(sec_firmware_img)) {
 315                 printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
 316                 return false;
 317         }
 318
 319         return true;
 320 }
 321
 322 #ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
 323 /*
 324  * The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
 325  * v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
 326  * number will be returned according to SMC Calling Conventions. But
 327  * when getting the NOT_SUPPORTED error number, we cannot ensure if
 328  * the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
 329  * won't be supported by this framework.
 330  * And if the secure firmware isn't running, return NOT_SUPPORTED.
 331  *
 332  * The return value on success is PSCI version in format
 333  * major[31:16]:minor[15:0].
 334  */
 335 unsigned int sec_firmware_support_psci_version(void)
 336 {
 337         if (current_el() == SEC_FIRMWARE_TARGET_EL)
 338                 return _sec_firmware_support_psci_version();
 339
 340         return PSCI_INVALID_VER;
 341 }
 342 #endif
 343
 344 /*
 345  * Check with sec_firmware if it supports random number generation
 346  * via HW RNG
 347  *
 348  * The return value will be true if it is supported
 349  */
 350 bool sec_firmware_support_hwrng(void)
 351 {
 352 #ifdef CONFIG_TFABOOT
 353         /* return true as TFA has one job ring reserved */
 354         return true;
 355 #endif
 356         if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
 357                         return true;
 358         }
 359
 360         return false;
 361 }
 362
 363 /*
 364  * sec_firmware_get_random - Get a random number from SEC Firmware
 365  * @rand:               random number buffer to be filled
 366  * @bytes:              Number of bytes of random number to be supported
 367  * @eret:               -1 in case of error, 0 for success
 368  */
 369 int sec_firmware_get_random(uint8_t *rand, int bytes)
 370 {
 371         unsigned long long num;
 372         struct pt_regs regs;
 373         int param1;
 374
 375         if (!bytes || bytes > 8) {
 376                 printf("Max Random bytes genration supported is 8\n");
 377                 return -1;
 378         }
 379 #define SIP_RNG_64 0xC200FF11
 380         regs.regs[0] = SIP_RNG_64;
 381
 382         if (bytes <= 4)
 383                 param1 = 0;
 384         else
 385                 param1 = 1;
 386         regs.regs[1] = param1;
 387
 388         smc_call(&regs);
 389
 390         if (regs.regs[0])
 391                 return -1;
 392
 393         num = regs.regs[1];
 394         memcpy(rand, &num, bytes);
 395
 396         return 0;
 397 }
 398
 399 /*
 400  * sec_firmware_init - Initialize the SEC Firmware
 401  * @sec_firmware_img:   the SEC Firmware image address
 402  * @eret_hold_l:        the address to hold exception return address low
 403  * @eret_hold_h:        the address to hold exception return address high
 404  * @loadable_l:         the address to hold loadable address low
 405  * @loadable_h:         the address to hold loadable address high
 406  */
 407 int sec_firmware_init(const void *sec_firmware_img,
 408                         u32 *eret_hold_l,
 409                         u32 *eret_hold_h,
 410                         u32 *loadable_l,
 411                         u32 *loadable_h)
 412 {
 413         int ret;
 414
 415         if (!sec_firmware_is_valid(sec_firmware_img))
 416                 return -EINVAL;
 417
 418         ret = sec_firmware_load_image(sec_firmware_img, loadable_l,
 419                                       loadable_h);
 420         if (ret) {
 421                 printf("SEC Firmware: Failed to load image\n");
 422                 return ret;
 423         } else if (sec_firmware_addr & SEC_FIRMWARE_LOADED) {
 424                 ret = sec_firmware_entry(eret_hold_l, eret_hold_h);
 425                 if (ret) {
 426                         printf("SEC Firmware: Failed to initialize\n");
 427                         return ret;
 428                 }
 429         }
 430
 431         debug("SEC Firmware: Return from SEC Firmware: current_el = %d\n",
 432               current_el());
 433
 434         /*
 435          * The PE will be turned into target EL when returned from
 436          * SEC Firmware.
 437          */
 438         if (current_el() != SEC_FIRMWARE_TARGET_EL)
 439                 return -EACCES;
 440
 441         sec_firmware_addr |= SEC_FIRMWARE_RUNNING;
 442
 443         /* Set exception table and enable caches if it isn't EL3 */
 444         if (current_el() != 3) {
 445                 c_runtime_cpu_setup();
 446                 enable_caches();
 447         }
 448
 449         return 0;
 450 }
 451
 452 /*
 453  * fdt_fix_kaslr - Add kalsr-seed node in Device tree
 454  * @fdt:                Device tree
 455  * @eret:               0 in case of error, 1 for success
 456  */
 457 int fdt_fixup_kaslr(void *fdt)
 458 {
 459         int nodeoffset;
 460         int err, ret = 0;
 461         u8 rand[8];
 462
 463 #if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
 464         /* Check if random seed generation is  supported */
 465         if (sec_firmware_support_hwrng() == false) {
 466                 printf("WARNING: SEC firmware not running, no kaslr-seed\n");
 467                 return 0;
 468         }
 469
 470         ret = sec_firmware_get_random(rand, 8);
 471         if (ret < 0) {
 472                 printf("WARNING: No random number to set kaslr-seed\n");
 473                 return 0;
 474         }
 475
 476         err = fdt_check_header(fdt);
 477         if (err < 0) {
 478                 printf("fdt_chosen: %s\n", fdt_strerror(err));
 479                 return 0;
 480         }
 481
 482         /* find or create "/chosen" node. */
 483         nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
 484         if (nodeoffset < 0)
 485                 return 0;
 486
 487         err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
 488                                   sizeof(rand));
 489         if (err < 0) {
 490                 printf("WARNING: can't set kaslr-seed %s.\n",
 491                        fdt_strerror(err));
 492                 return 0;
 493         }
 494         ret = 1;
 495 #endif
 496
 497         return ret;
 498 }