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 <fdt_support.h>
  10 #include <image.h>
  11 #include <asm/cache.h>
  12 #include <linux/kernel.h>
  13 #include <asm/io.h>
  14 #include <asm/system.h>
  15 #include <asm/types.h>
  16 #include <asm/macro.h>
  17 #include <asm/armv8/sec_firmware.h>
  18
  19 DECLARE_GLOBAL_DATA_PTR;
  20 extern void c_runtime_cpu_setup(void);
  21
  22 #define SEC_FIRMWARE_LOADED     0x1
  23 #define SEC_FIRMWARE_RUNNING    0x2
  24 #define SEC_FIRMWARE_ADDR_MASK  (~0x3)
  25 /*
  26  * Secure firmware load addr
  27  * Flags used: 0x1 secure firmware has been loaded to secure memory
  28  *             0x2 secure firmware is running
  29  */
  30 phys_addr_t sec_firmware_addr;
  31
  32 #ifndef SEC_FIRMWARE_FIT_IMAGE
  33 #define SEC_FIRMWARE_FIT_IMAGE          "firmware"
  34 #endif
  35 #ifndef SEC_FIRMWARE_FIT_CNF_NAME
  36 #define SEC_FIRMWARE_FIT_CNF_NAME       "config-1"
  37 #endif
  38 #ifndef SEC_FIRMWARE_TARGET_EL
  39 #define SEC_FIRMWARE_TARGET_EL          2
  40 #endif
  41
  42 static int sec_firmware_get_data(const void *sec_firmware_img,
  43                                 const void **data, size_t *size)
  44 {
  45         int conf_node_off, fw_node_off;
  46         char *conf_node_name = NULL;
  47         char *desc;
  48         int ret;
  49
  50         conf_node_name = SEC_FIRMWARE_FIT_CNF_NAME;
  51
  52         conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
  53         if (conf_node_off < 0) {
  54                 printf("SEC Firmware: %s: no such config\n", conf_node_name);
  55                 return -ENOENT;
  56         }
  57
  58         fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
  59                         SEC_FIRMWARE_FIT_IMAGE);
  60         if (fw_node_off < 0) {
  61                 printf("SEC Firmware: No '%s' in config\n",
  62                        SEC_FIRMWARE_FIT_IMAGE);
  63                 return -ENOLINK;
  64         }
  65
  66         /* Verify secure firmware image */
  67         if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
  68                 printf("SEC Firmware: Bad firmware image (bad CRC)\n");
  69                 return -EINVAL;
  70         }
  71
  72         if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
  73                 printf("SEC Firmware: Can't get %s subimage data/size",
  74                        SEC_FIRMWARE_FIT_IMAGE);
  75                 return -ENOENT;
  76         }
  77
  78         ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
  79         if (ret)
  80                 printf("SEC Firmware: Can't get description\n");
  81         else
  82                 printf("%s\n", desc);
  83
  84         return ret;
  85 }
  86
  87 /*
  88  * SEC Firmware FIT image parser checks if the image is in FIT
  89  * format, verifies integrity of the image and calculates raw
  90  * image address and size values.
  91  *
  92  * Returns 0 on success and a negative errno on error task fail.
  93  */
  94 static int sec_firmware_parse_image(const void *sec_firmware_img,
  95                                         const void **raw_image_addr,
  96                                         size_t *raw_image_size)
  97 {
  98         int ret;
  99
 100         ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
 101                                         raw_image_size);
 102         if (ret)
 103                 return ret;
 104
 105         debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
 106               *raw_image_addr, *raw_image_size);
 107
 108         return 0;
 109 }
 110
 111 /*
 112  * SEC Firmware FIT image parser to check if any loadable is
 113  * present. If present, verify integrity of the loadable and
 114  * copy loadable to address provided in (loadable_h, loadable_l).
 115  *
 116  * Returns 0 on success and a negative errno on error task fail.
 117  */
 118 static int sec_firmware_check_copy_loadable(const void *sec_firmware_img,
 119                                             u32 *loadable_l, u32 *loadable_h)
 120 {
 121         phys_addr_t sec_firmware_loadable_addr = 0;
 122         int conf_node_off, ld_node_off, images;
 123         char *conf_node_name = NULL;
 124         const void *data;
 125         size_t size;
 126         ulong load;
 127         const char *name, *str, *type;
 128         int len;
 129
 130         conf_node_name = SEC_FIRMWARE_FIT_CNF_NAME;
 131
 132         conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
 133         if (conf_node_off < 0) {
 134                 printf("SEC Firmware: %s: no such config\n", conf_node_name);
 135                 return -ENOENT;
 136         }
 137
 138         /* find the node holding the images information */
 139         images = fdt_path_offset(sec_firmware_img, FIT_IMAGES_PATH);
 140         if (images < 0) {
 141                 printf("%s: Cannot find /images node: %d\n", __func__, images);
 142                 return -1;
 143         }
 144
 145         type = FIT_LOADABLE_PROP;
 146
 147         name = fdt_getprop(sec_firmware_img, conf_node_off, type, &len);
 148         if (!name) {
 149                 /* Loadables not present */
 150                 return 0;
 151         }
 152
 153         printf("SEC Firmware: '%s' present in config\n", type);
 154
 155         for (str = name; str && ((str - name) < len);
 156              str = strchr(str, '\0') + 1) {
 157                 printf("%s: '%s'\n", type, str);
 158                 ld_node_off = fdt_subnode_offset(sec_firmware_img, images, str);
 159                 if (ld_node_off < 0) {
 160                         printf("cannot find image node '%s': %d\n", str,
 161                                ld_node_off);
 162                         return -EINVAL;
 163                 }
 164
 165                 /* Verify secure firmware image */
 166                 if (!(fit_image_verify(sec_firmware_img, ld_node_off))) {
 167                         printf("SEC Loadable: Bad loadable image (bad CRC)\n");
 168                         return -EINVAL;
 169                 }
 170
 171                 if (fit_image_get_data(sec_firmware_img, ld_node_off,
 172                                        &data, &size)) {
 173                         printf("SEC Loadable: Can't get subimage data/size");
 174                         return -ENOENT;
 175                 }
 176
 177                 /* Get load address, treated as load offset to secure memory */
 178                 if (fit_image_get_load(sec_firmware_img, ld_node_off, &load)) {
 179                         printf("SEC Loadable: Can't get subimage load");
 180                         return -ENOENT;
 181                 }
 182
 183                 /* Compute load address for loadable in secure memory */
 184                 sec_firmware_loadable_addr = (sec_firmware_addr -
 185                                                 gd->arch.tlb_size) + load;
 186
 187                 /* Copy loadable to secure memory and flush dcache */
 188                 debug("%s copied to address 0x%p\n",
 189                       FIT_LOADABLE_PROP, (void *)sec_firmware_loadable_addr);
 190                 memcpy((void *)sec_firmware_loadable_addr, data, size);
 191                 flush_dcache_range(sec_firmware_loadable_addr,
 192                                    sec_firmware_loadable_addr + size);
 193
 194                 /* Populate loadable address only for Trusted OS */
 195                 if (!strcmp(str, "trustedOS@1")) {
 196                         /*
 197                          * Populate address ptrs for loadable image with
 198                          * loadbale addr
 199                          */
 200                         out_le32(loadable_l, (sec_firmware_loadable_addr &
 201                                               WORD_MASK));
 202                         out_le32(loadable_h, (sec_firmware_loadable_addr >>
 203                                               WORD_SHIFT));
 204                 }
 205         }
 206
 207         return 0;
 208 }
 209
 210 static int sec_firmware_copy_image(const char *title,
 211                          u64 image_addr, u32 image_size, u64 sec_firmware)
 212 {
 213         debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
 214         memcpy((void *)sec_firmware, (void *)image_addr, image_size);
 215         flush_dcache_range(sec_firmware, sec_firmware + image_size);
 216
 217         return 0;
 218 }
 219
 220 /*
 221  * This function will parse the SEC Firmware image, and then load it
 222  * to secure memory. Also load any loadable if present along with SEC
 223  * Firmware image.
 224  */
 225 static int sec_firmware_load_image(const void *sec_firmware_img,
 226                                    u32 *loadable_l, u32 *loadable_h)
 227 {
 228         const void *raw_image_addr;
 229         size_t raw_image_size = 0;
 230         int ret;
 231
 232         /*
 233          * The Excetpion Level must be EL3 to load and initialize
 234          * the SEC Firmware.
 235          */
 236         if (current_el() != 3) {
 237                 ret = -EACCES;
 238                 goto out;
 239         }
 240
 241 #ifdef CONFIG_SYS_MEM_RESERVE_SECURE
 242         /*
 243          * The SEC Firmware must be stored in secure memory.
 244          * Append SEC Firmware to secure mmu table.
 245          */
 246         if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
 247                 ret = -ENXIO;
 248                 goto out;
 249         }
 250
 251         sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
 252                         gd->arch.tlb_size;
 253 #else
 254 #error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
 255 #endif
 256
 257         /* Align SEC Firmware base address to 4K */
 258         sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
 259         debug("SEC Firmware: Load address: 0x%llx\n",
 260               sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
 261
 262         ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
 263                         &raw_image_size);
 264         if (ret)
 265                 goto out;
 266
 267         /* TODO:
 268          * Check if the end addr of SEC Firmware has been extend the secure
 269          * memory.
 270          */
 271
 272         /* Copy the secure firmware to secure memory */
 273         ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
 274                         raw_image_size, sec_firmware_addr &
 275                         SEC_FIRMWARE_ADDR_MASK);
 276         if (ret)
 277                 goto out;
 278
 279         /*
 280          * Check if any loadable are present along with firmware image, if
 281          * present load them.
 282          */
 283         ret = sec_firmware_check_copy_loadable(sec_firmware_img, loadable_l,
 284                                                loadable_h);
 285         if (ret)
 286                 goto out;
 287
 288         sec_firmware_addr |= SEC_FIRMWARE_LOADED;
 289         debug("SEC Firmware: Entry point: 0x%llx\n",
 290               sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
 291
 292         return 0;
 293
 294 out:
 295         printf("SEC Firmware: error (%d)\n", ret);
 296         sec_firmware_addr = 0;
 297
 298         return ret;
 299 }
 300
 301 static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
 302 {
 303         const void *entry = (void *)(sec_firmware_addr &
 304                                 SEC_FIRMWARE_ADDR_MASK);
 305
 306         return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
 307 }
 308
 309 /* Check the secure firmware FIT image */
 310 __weak bool sec_firmware_is_valid(const void *sec_firmware_img)
 311 {
 312         if (fdt_check_header(sec_firmware_img)) {
 313                 printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
 314                 return false;
 315         }
 316
 317         if (!fit_check_format(sec_firmware_img)) {
 318                 printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
 319                 return false;
 320         }
 321
 322         return true;
 323 }
 324
 325 #ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
 326 /*
 327  * The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
 328  * v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
 329  * number will be returned according to SMC Calling Conventions. But
 330  * when getting the NOT_SUPPORTED error number, we cannot ensure if
 331  * the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
 332  * won't be supported by this framework.
 333  * And if the secure firmware isn't running, return NOT_SUPPORTED.
 334  *
 335  * The return value on success is PSCI version in format
 336  * major[31:16]:minor[15:0].
 337  */
 338 unsigned int sec_firmware_support_psci_version(void)
 339 {
 340         if (current_el() == SEC_FIRMWARE_TARGET_EL)
 341                 return _sec_firmware_support_psci_version();
 342
 343         return PSCI_INVALID_VER;
 344 }
 345 #endif
 346
 347 /*
 348  * Check with sec_firmware if it supports random number generation
 349  * via HW RNG
 350  *
 351  * The return value will be true if it is supported
 352  */
 353 bool sec_firmware_support_hwrng(void)
 354 {
 355 #ifdef CONFIG_TFABOOT
 356         /* return true as TFA has one job ring reserved */
 357         return true;
 358 #endif
 359         if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
 360                 return true;
 361         }
 362
 363         return false;
 364 }
 365
 366 /*
 367  * sec_firmware_get_random - Get a random number from SEC Firmware
 368  * @rand:               random number buffer to be filled
 369  * @bytes:              Number of bytes of random number to be supported
 370  * @eret:               -1 in case of error, 0 for success
 371  */
 372 int sec_firmware_get_random(uint8_t *rand, int bytes)
 373 {
 374         unsigned long long num;
 375         struct pt_regs regs;
 376         int param1;
 377
 378         if (!bytes || bytes > 8) {
 379                 printf("Max Random bytes genration supported is 8\n");
 380                 return -1;
 381         }
 382 #define SIP_RNG_64 0xC200FF11
 383         regs.regs[0] = SIP_RNG_64;
 384
 385         if (bytes <= 4)
 386                 param1 = 0;
 387         else
 388                 param1 = 1;
 389         regs.regs[1] = param1;
 390
 391         smc_call(&regs);
 392
 393         if (regs.regs[0])
 394                 return -1;
 395
 396         num = regs.regs[1];
 397         memcpy(rand, &num, bytes);
 398
 399         return 0;
 400 }
 401
 402 /*
 403  * sec_firmware_init - Initialize the SEC Firmware
 404  * @sec_firmware_img:   the SEC Firmware image address
 405  * @eret_hold_l:        the address to hold exception return address low
 406  * @eret_hold_h:        the address to hold exception return address high
 407  * @loadable_l:         the address to hold loadable address low
 408  * @loadable_h:         the address to hold loadable address high
 409  */
 410 int sec_firmware_init(const void *sec_firmware_img,
 411                         u32 *eret_hold_l,
 412                         u32 *eret_hold_h,
 413                         u32 *loadable_l,
 414                         u32 *loadable_h)
 415 {
 416         int ret;
 417
 418         if (!sec_firmware_is_valid(sec_firmware_img))
 419                 return -EINVAL;
 420
 421         ret = sec_firmware_load_image(sec_firmware_img, loadable_l,
 422                                       loadable_h);
 423         if (ret) {
 424                 printf("SEC Firmware: Failed to load image\n");
 425                 return ret;
 426         } else if (sec_firmware_addr & SEC_FIRMWARE_LOADED) {
 427                 ret = sec_firmware_entry(eret_hold_l, eret_hold_h);
 428                 if (ret) {
 429                         printf("SEC Firmware: Failed to initialize\n");
 430                         return ret;
 431                 }
 432         }
 433
 434         debug("SEC Firmware: Return from SEC Firmware: current_el = %d\n",
 435               current_el());
 436
 437         /*
 438          * The PE will be turned into target EL when returned from
 439          * SEC Firmware.
 440          */
 441         if (current_el() != SEC_FIRMWARE_TARGET_EL)
 442                 return -EACCES;
 443
 444         sec_firmware_addr |= SEC_FIRMWARE_RUNNING;
 445
 446         /* Set exception table and enable caches if it isn't EL3 */
 447         if (current_el() != 3) {
 448                 c_runtime_cpu_setup();
 449                 enable_caches();
 450         }
 451
 452         return 0;
 453 }
 454
 455 /*
 456  * fdt_fix_kaslr - Add kalsr-seed node in Device tree
 457  * @fdt:                Device tree
 458  * @eret:               0 in case of error, 1 for success
 459  */
 460 int fdt_fixup_kaslr(void *fdt)
 461 {
 462         int nodeoffset;
 463         int err, ret = 0;
 464         u8 rand[8];
 465
 466 #if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
 467         /* Check if random seed generation is  supported */
 468         if (sec_firmware_support_hwrng() == false) {
 469                 printf("WARNING: SEC firmware not running, no kaslr-seed\n");
 470                 return 0;
 471         }
 472
 473         ret = sec_firmware_get_random(rand, 8);
 474         if (ret < 0) {
 475                 printf("WARNING: No random number to set kaslr-seed\n");
 476                 return 0;
 477         }
 478
 479         err = fdt_check_header(fdt);
 480         if (err < 0) {
 481                 printf("fdt_chosen: %s\n", fdt_strerror(err));
 482                 return 0;
 483         }
 484
 485         /* find or create "/chosen" node. */
 486         nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
 487         if (nodeoffset < 0)
 488                 return 0;
 489
 490         err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
 491                                   sizeof(rand));
 492         if (err < 0) {
 493                 printf("WARNING: can't set kaslr-seed %s.\n",
 494                        fdt_strerror(err));
 495                 return 0;
 496         }
 497         ret = 1;
 498 #endif
 499
 500         return ret;
 501 }