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 <log.h>
  12 #include <asm/cache.h>
  13 #include <asm/global_data.h>
  14 #include <asm/ptrace.h>
  15 #include <linux/kernel.h>
  16 #include <asm/io.h>
  17 #include <asm/system.h>
  18 #include <asm/types.h>
  19 #include <asm/macro.h>
  20 #include <asm/armv8/sec_firmware.h>
  21
  22 DECLARE_GLOBAL_DATA_PTR;
  23 extern void c_runtime_cpu_setup(void);
  24
  25 #define SEC_FIRMWARE_LOADED     0x1
  26 #define SEC_FIRMWARE_RUNNING    0x2
  27 #define SEC_FIRMWARE_ADDR_MASK  (~0x3)
  28 /*
  29  * Secure firmware load addr
  30  * Flags used: 0x1 secure firmware has been loaded to secure memory
  31  *             0x2 secure firmware is running
  32  */
  33 phys_addr_t sec_firmware_addr;
  34
  35 #ifndef SEC_FIRMWARE_FIT_IMAGE
  36 #define SEC_FIRMWARE_FIT_IMAGE          "firmware"
  37 #endif
  38 #ifndef SEC_FIRMWARE_FIT_CNF_NAME
  39 #define SEC_FIRMWARE_FIT_CNF_NAME       "config-1"
  40 #endif
  41 #ifndef SEC_FIRMWARE_TARGET_EL
  42 #define SEC_FIRMWARE_TARGET_EL          2
  43 #endif
  44
  45 static int sec_firmware_get_data(const void *sec_firmware_img,
  46                                 const void **data, size_t *size)
  47 {
  48         int conf_node_off, fw_node_off;
  49         char *conf_node_name = NULL;
  50         char *desc;
  51         int ret;
  52
  53         conf_node_name = SEC_FIRMWARE_FIT_CNF_NAME;
  54
  55         conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
  56         if (conf_node_off < 0) {
  57                 printf("SEC Firmware: %s: no such config\n", conf_node_name);
  58                 return -ENOENT;
  59         }
  60
  61         fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
  62                         SEC_FIRMWARE_FIT_IMAGE);
  63         if (fw_node_off < 0) {
  64                 printf("SEC Firmware: No '%s' in config\n",
  65                        SEC_FIRMWARE_FIT_IMAGE);
  66                 return -ENOLINK;
  67         }
  68
  69         /* Verify secure firmware image */
  70         if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
  71                 printf("SEC Firmware: Bad firmware image (bad CRC)\n");
  72                 return -EINVAL;
  73         }
  74
  75         if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
  76                 printf("SEC Firmware: Can't get %s subimage data/size",
  77                        SEC_FIRMWARE_FIT_IMAGE);
  78                 return -ENOENT;
  79         }
  80
  81         ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
  82         if (ret)
  83                 printf("SEC Firmware: Can't get description\n");
  84         else
  85                 printf("%s\n", desc);
  86
  87         return ret;
  88 }
  89
  90 /*
  91  * SEC Firmware FIT image parser checks if the image is in FIT
  92  * format, verifies integrity of the image and calculates raw
  93  * image address and size values.
  94  *
  95  * Returns 0 on success and a negative errno on error task fail.
  96  */
  97 static int sec_firmware_parse_image(const void *sec_firmware_img,
  98                                         const void **raw_image_addr,
  99                                         size_t *raw_image_size)
 100 {
 101         int ret;
 102
 103         ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
 104                                         raw_image_size);
 105         if (ret)
 106                 return ret;
 107
 108         debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
 109               *raw_image_addr, *raw_image_size);
 110
 111         return 0;
 112 }
 113
 114 /*
 115  * SEC Firmware FIT image parser to check if any loadable is
 116  * present. If present, verify integrity of the loadable and
 117  * copy loadable to address provided in (loadable_h, loadable_l).
 118  *
 119  * Returns 0 on success and a negative errno on error task fail.
 120  */
 121 static int sec_firmware_check_copy_loadable(const void *sec_firmware_img,
 122                                             u32 *loadable_l, u32 *loadable_h)
 123 {
 124         phys_addr_t sec_firmware_loadable_addr = 0;
 125         int conf_node_off, ld_node_off, images;
 126         char *conf_node_name = NULL;
 127         const void *data;
 128         size_t size;
 129         ulong load;
 130         const char *name, *str, *type;
 131         int len;
 132
 133         conf_node_name = SEC_FIRMWARE_FIT_CNF_NAME;
 134
 135         conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
 136         if (conf_node_off < 0) {
 137                 printf("SEC Firmware: %s: no such config\n", conf_node_name);
 138                 return -ENOENT;
 139         }
 140
 141         /* find the node holding the images information */
 142         images = fdt_path_offset(sec_firmware_img, FIT_IMAGES_PATH);
 143         if (images < 0) {
 144                 printf("%s: Cannot find /images node: %d\n", __func__, images);
 145                 return -1;
 146         }
 147
 148         type = FIT_LOADABLE_PROP;
 149
 150         name = fdt_getprop(sec_firmware_img, conf_node_off, type, &len);
 151         if (!name) {
 152                 /* Loadables not present */
 153                 return 0;
 154         }
 155
 156         printf("SEC Firmware: '%s' present in config\n", type);
 157
 158         for (str = name; str && ((str - name) < len);
 159              str = strchr(str, '\0') + 1) {
 160                 printf("%s: '%s'\n", type, str);
 161                 ld_node_off = fdt_subnode_offset(sec_firmware_img, images, str);
 162                 if (ld_node_off < 0) {
 163                         printf("cannot find image node '%s': %d\n", str,
 164                                ld_node_off);
 165                         return -EINVAL;
 166                 }
 167
 168                 /* Verify secure firmware image */
 169                 if (!(fit_image_verify(sec_firmware_img, ld_node_off))) {
 170                         printf("SEC Loadable: Bad loadable image (bad CRC)\n");
 171                         return -EINVAL;
 172                 }
 173
 174                 if (fit_image_get_data(sec_firmware_img, ld_node_off,
 175                                        &data, &size)) {
 176                         printf("SEC Loadable: Can't get subimage data/size");
 177                         return -ENOENT;
 178                 }
 179
 180                 /* Get load address, treated as load offset to secure memory */
 181                 if (fit_image_get_load(sec_firmware_img, ld_node_off, &load)) {
 182                         printf("SEC Loadable: Can't get subimage load");
 183                         return -ENOENT;
 184                 }
 185
 186                 /* Compute load address for loadable in secure memory */
 187                 sec_firmware_loadable_addr = (sec_firmware_addr -
 188                                                 gd->arch.tlb_size) + load;
 189
 190                 /* Copy loadable to secure memory and flush dcache */
 191                 debug("%s copied to address 0x%p\n",
 192                       FIT_LOADABLE_PROP, (void *)sec_firmware_loadable_addr);
 193                 memcpy((void *)sec_firmware_loadable_addr, data, size);
 194                 flush_dcache_range(sec_firmware_loadable_addr,
 195                                    sec_firmware_loadable_addr + size);
 196
 197                 /* Populate loadable address only for Trusted OS */
 198                 if (!strcmp(str, "trustedOS@1")) {
 199                         /*
 200                          * Populate address ptrs for loadable image with
 201                          * loadbale addr
 202                          */
 203                         out_le32(loadable_l, (sec_firmware_loadable_addr &
 204                                               WORD_MASK));
 205                         out_le32(loadable_h, (sec_firmware_loadable_addr >>
 206                                               WORD_SHIFT));
 207                 }
 208         }
 209
 210         return 0;
 211 }
 212
 213 static int sec_firmware_copy_image(const char *title,
 214                          u64 image_addr, u32 image_size, u64 sec_firmware)
 215 {
 216         debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
 217         memcpy((void *)sec_firmware, (void *)image_addr, image_size);
 218         flush_dcache_range(sec_firmware, sec_firmware + image_size);
 219
 220         return 0;
 221 }
 222
 223 /*
 224  * This function will parse the SEC Firmware image, and then load it
 225  * to secure memory. Also load any loadable if present along with SEC
 226  * Firmware image.
 227  */
 228 static int sec_firmware_load_image(const void *sec_firmware_img,
 229                                    u32 *loadable_l, u32 *loadable_h)
 230 {
 231         const void *raw_image_addr;
 232         size_t raw_image_size = 0;
 233         int ret;
 234
 235         /*
 236          * The Excetpion Level must be EL3 to load and initialize
 237          * the SEC Firmware.
 238          */
 239         if (current_el() != 3) {
 240                 ret = -EACCES;
 241                 goto out;
 242         }
 243
 244 #ifdef CONFIG_SYS_MEM_RESERVE_SECURE
 245         /*
 246          * The SEC Firmware must be stored in secure memory.
 247          * Append SEC Firmware to secure mmu table.
 248          */
 249         if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
 250                 ret = -ENXIO;
 251                 goto out;
 252         }
 253
 254         sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
 255                         gd->arch.tlb_size;
 256 #else
 257 #error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
 258 #endif
 259
 260         /* Align SEC Firmware base address to 4K */
 261         sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
 262         debug("SEC Firmware: Load address: 0x%llx\n",
 263               sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
 264
 265         ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
 266                         &raw_image_size);
 267         if (ret)
 268                 goto out;
 269
 270         /* TODO:
 271          * Check if the end addr of SEC Firmware has been extend the secure
 272          * memory.
 273          */
 274
 275         /* Copy the secure firmware to secure memory */
 276         ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
 277                         raw_image_size, sec_firmware_addr &
 278                         SEC_FIRMWARE_ADDR_MASK);
 279         if (ret)
 280                 goto out;
 281
 282         /*
 283          * Check if any loadable are present along with firmware image, if
 284          * present load them.
 285          */
 286         ret = sec_firmware_check_copy_loadable(sec_firmware_img, loadable_l,
 287                                                loadable_h);
 288         if (ret)
 289                 goto out;
 290
 291         sec_firmware_addr |= SEC_FIRMWARE_LOADED;
 292         debug("SEC Firmware: Entry point: 0x%llx\n",
 293               sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
 294
 295         return 0;
 296
 297 out:
 298         printf("SEC Firmware: error (%d)\n", ret);
 299         sec_firmware_addr = 0;
 300
 301         return ret;
 302 }
 303
 304 static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
 305 {
 306         const void *entry = (void *)(sec_firmware_addr &
 307                                 SEC_FIRMWARE_ADDR_MASK);
 308
 309         return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
 310 }
 311
 312 /* Check the secure firmware FIT image */
 313 __weak bool sec_firmware_is_valid(const void *sec_firmware_img)
 314 {
 315         if (fdt_check_header(sec_firmware_img)) {
 316                 printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
 317                 return false;
 318         }
 319
 320         if (fit_check_format(sec_firmware_img, IMAGE_SIZE_INVAL)) {
 321                 printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
 322                 return false;
 323         }
 324
 325         return true;
 326 }
 327
 328 #ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
 329 /*
 330  * The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
 331  * v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
 332  * number will be returned according to SMC Calling Conventions. But
 333  * when getting the NOT_SUPPORTED error number, we cannot ensure if
 334  * the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
 335  * won't be supported by this framework.
 336  * And if the secure firmware isn't running, return NOT_SUPPORTED.
 337  *
 338  * The return value on success is PSCI version in format
 339  * major[31:16]:minor[15:0].
 340  */
 341 unsigned int sec_firmware_support_psci_version(void)
 342 {
 343         if (current_el() == SEC_FIRMWARE_TARGET_EL)
 344                 return _sec_firmware_support_psci_version();
 345
 346         return PSCI_INVALID_VER;
 347 }
 348 #endif
 349
 350 /*
 351  * Check with sec_firmware if it supports random number generation
 352  * via HW RNG
 353  *
 354  * The return value will be true if it is supported
 355  */
 356 bool sec_firmware_support_hwrng(void)
 357 {
 358 #ifdef CONFIG_TFABOOT
 359         /* return true as TFA has one job ring reserved */
 360         return true;
 361 #endif
 362         if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
 363                 return true;
 364         }
 365
 366         return false;
 367 }
 368
 369 /*
 370  * sec_firmware_get_random - Get a random number from SEC Firmware
 371  * @rand:               random number buffer to be filled
 372  * @bytes:              Number of bytes of random number to be supported
 373  * @eret:               -1 in case of error, 0 for success
 374  */
 375 int sec_firmware_get_random(uint8_t *rand, int bytes)
 376 {
 377         unsigned long long num;
 378         struct pt_regs regs;
 379         int param1;
 380
 381         if (!bytes || bytes > 8) {
 382                 printf("Max Random bytes genration supported is 8\n");
 383                 return -1;
 384         }
 385 #define SIP_RNG_64 0xC200FF11
 386         regs.regs[0] = SIP_RNG_64;
 387
 388         if (bytes <= 4)
 389                 param1 = 0;
 390         else
 391                 param1 = 1;
 392         regs.regs[1] = param1;
 393
 394         smc_call(&regs);
 395
 396         if (regs.regs[0])
 397                 return -1;
 398
 399         num = regs.regs[1];
 400         memcpy(rand, &num, bytes);
 401
 402         return 0;
 403 }
 404
 405 /*
 406  * sec_firmware_init - Initialize the SEC Firmware
 407  * @sec_firmware_img:   the SEC Firmware image address
 408  * @eret_hold_l:        the address to hold exception return address low
 409  * @eret_hold_h:        the address to hold exception return address high
 410  * @loadable_l:         the address to hold loadable address low
 411  * @loadable_h:         the address to hold loadable address high
 412  */
 413 int sec_firmware_init(const void *sec_firmware_img,
 414                         u32 *eret_hold_l,
 415                         u32 *eret_hold_h,
 416                         u32 *loadable_l,
 417                         u32 *loadable_h)
 418 {
 419         int ret;
 420
 421         if (!sec_firmware_is_valid(sec_firmware_img))
 422                 return -EINVAL;
 423
 424         ret = sec_firmware_load_image(sec_firmware_img, loadable_l,
 425                                       loadable_h);
 426         if (ret) {
 427                 printf("SEC Firmware: Failed to load image\n");
 428                 return ret;
 429         } else if (sec_firmware_addr & SEC_FIRMWARE_LOADED) {
 430                 ret = sec_firmware_entry(eret_hold_l, eret_hold_h);
 431                 if (ret) {
 432                         printf("SEC Firmware: Failed to initialize\n");
 433                         return ret;
 434                 }
 435         }
 436
 437         debug("SEC Firmware: Return from SEC Firmware: current_el = %d\n",
 438               current_el());
 439
 440         /*
 441          * The PE will be turned into target EL when returned from
 442          * SEC Firmware.
 443          */
 444         if (current_el() != SEC_FIRMWARE_TARGET_EL)
 445                 return -EACCES;
 446
 447         sec_firmware_addr |= SEC_FIRMWARE_RUNNING;
 448
 449         /* Set exception table and enable caches if it isn't EL3 */
 450         if (current_el() != 3) {
 451                 c_runtime_cpu_setup();
 452                 enable_caches();
 453         }
 454
 455         return 0;
 456 }
 457
 458 /*
 459  * fdt_fix_kaslr - Add kalsr-seed node in Device tree
 460  * @fdt:                Device tree
 461  * @eret:               0 in case of error, 1 for success
 462  */
 463 int fdt_fixup_kaslr(void *fdt)
 464 {
 465         int nodeoffset;
 466         int err, ret = 0;
 467         u8 rand[8];
 468
 469 #if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
 470         /* Check if random seed generation is  supported */
 471         if (sec_firmware_support_hwrng() == false) {
 472                 printf("WARNING: SEC firmware not running, no kaslr-seed\n");
 473                 return 0;
 474         }
 475
 476         ret = sec_firmware_get_random(rand, 8);
 477         if (ret < 0) {
 478                 printf("WARNING: No random number to set kaslr-seed\n");
 479                 return 0;
 480         }
 481
 482         err = fdt_check_header(fdt);
 483         if (err < 0) {
 484                 printf("fdt_chosen: %s\n", fdt_strerror(err));
 485                 return 0;
 486         }
 487
 488         /* find or create "/chosen" node. */
 489         nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
 490         if (nodeoffset < 0)
 491                 return 0;
 492
 493         err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
 494                                   sizeof(rand));
 495         if (err < 0) {
 496                 printf("WARNING: can't set kaslr-seed %s.\n",
 497                        fdt_strerror(err));
 498                 return 0;
 499         }
 500         ret = 1;
 501 #endif
 502
 503         return ret;
 504 }