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 <linux/arm-smccc.h>
  17 #include <asm/io.h>
  18 #include <asm/system.h>
  19 #include <asm/types.h>
  20 #include <asm/macro.h>
  21 #include <asm/armv8/sec_firmware.h>
  22
  23 DECLARE_GLOBAL_DATA_PTR;
  24 extern void c_runtime_cpu_setup(void);
  25
  26 #define SEC_FIRMWARE_LOADED     0x1
  27 #define SEC_FIRMWARE_RUNNING    0x2
  28 #define SEC_FIRMWARE_ADDR_MASK  (~0x3)
  29 /*
  30  * Secure firmware load addr
  31  * Flags used: 0x1 secure firmware has been loaded to secure memory
  32  *             0x2 secure firmware is running
  33  */
  34 phys_addr_t sec_firmware_addr;
  35
  36 #ifndef SEC_FIRMWARE_FIT_IMAGE
  37 #define SEC_FIRMWARE_FIT_IMAGE          "firmware"
  38 #endif
  39 #ifndef SEC_FIRMWARE_FIT_CNF_NAME
  40 #define SEC_FIRMWARE_FIT_CNF_NAME       "config-1"
  41 #endif
  42 #ifndef SEC_FIRMWARE_TARGET_EL
  43 #define SEC_FIRMWARE_TARGET_EL          2
  44 #endif
  45
  46 static int sec_firmware_get_data(const void *sec_firmware_img,
  47                                 const void **data, size_t *size)
  48 {
  49         int conf_node_off, fw_node_off;
  50         char *conf_node_name = NULL;
  51         char *desc;
  52         int ret;
  53
  54         conf_node_name = SEC_FIRMWARE_FIT_CNF_NAME;
  55
  56         conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
  57         if (conf_node_off < 0) {
  58                 printf("SEC Firmware: %s: no such config\n", conf_node_name);
  59                 return -ENOENT;
  60         }
  61
  62         fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
  63                         SEC_FIRMWARE_FIT_IMAGE);
  64         if (fw_node_off < 0) {
  65                 printf("SEC Firmware: No '%s' in config\n",
  66                        SEC_FIRMWARE_FIT_IMAGE);
  67                 return -ENOLINK;
  68         }
  69
  70         /* Verify secure firmware image */
  71         if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
  72                 printf("SEC Firmware: Bad firmware image (bad CRC)\n");
  73                 return -EINVAL;
  74         }
  75
  76         if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
  77                 printf("SEC Firmware: Can't get %s subimage data/size",
  78                        SEC_FIRMWARE_FIT_IMAGE);
  79                 return -ENOENT;
  80         }
  81
  82         ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
  83         if (ret)
  84                 printf("SEC Firmware: Can't get description\n");
  85         else
  86                 printf("%s\n", desc);
  87
  88         return ret;
  89 }
  90
  91 /*
  92  * SEC Firmware FIT image parser checks if the image is in FIT
  93  * format, verifies integrity of the image and calculates raw
  94  * image address and size values.
  95  *
  96  * Returns 0 on success and a negative errno on error task fail.
  97  */
  98 static int sec_firmware_parse_image(const void *sec_firmware_img,
  99                                         const void **raw_image_addr,
 100                                         size_t *raw_image_size)
 101 {
 102         int ret;
 103
 104         ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
 105                                         raw_image_size);
 106         if (ret)
 107                 return ret;
 108
 109         debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
 110               *raw_image_addr, *raw_image_size);
 111
 112         return 0;
 113 }
 114
 115 /*
 116  * SEC Firmware FIT image parser to check if any loadable is
 117  * present. If present, verify integrity of the loadable and
 118  * copy loadable to address provided in (loadable_h, loadable_l).
 119  *
 120  * Returns 0 on success and a negative errno on error task fail.
 121  */
 122 static int sec_firmware_check_copy_loadable(const void *sec_firmware_img,
 123                                             u32 *loadable_l, u32 *loadable_h)
 124 {
 125         phys_addr_t sec_firmware_loadable_addr = 0;
 126         int conf_node_off, ld_node_off, images;
 127         char *conf_node_name = NULL;
 128         const void *data;
 129         size_t size;
 130         ulong load;
 131         const char *name, *str, *type;
 132         int len;
 133
 134         conf_node_name = SEC_FIRMWARE_FIT_CNF_NAME;
 135
 136         conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
 137         if (conf_node_off < 0) {
 138                 printf("SEC Firmware: %s: no such config\n", conf_node_name);
 139                 return -ENOENT;
 140         }
 141
 142         /* find the node holding the images information */
 143         images = fdt_path_offset(sec_firmware_img, FIT_IMAGES_PATH);
 144         if (images < 0) {
 145                 printf("%s: Cannot find /images node: %d\n", __func__, images);
 146                 return -1;
 147         }
 148
 149         type = FIT_LOADABLE_PROP;
 150
 151         name = fdt_getprop(sec_firmware_img, conf_node_off, type, &len);
 152         if (!name) {
 153                 /* Loadables not present */
 154                 return 0;
 155         }
 156
 157         printf("SEC Firmware: '%s' present in config\n", type);
 158
 159         for (str = name; str && ((str - name) < len);
 160              str = strchr(str, '\0') + 1) {
 161                 printf("%s: '%s'\n", type, str);
 162                 ld_node_off = fdt_subnode_offset(sec_firmware_img, images, str);
 163                 if (ld_node_off < 0) {
 164                         printf("cannot find image node '%s': %d\n", str,
 165                                ld_node_off);
 166                         return -EINVAL;
 167                 }
 168
 169                 /* Verify secure firmware image */
 170                 if (!(fit_image_verify(sec_firmware_img, ld_node_off))) {
 171                         printf("SEC Loadable: Bad loadable image (bad CRC)\n");
 172                         return -EINVAL;
 173                 }
 174
 175                 if (fit_image_get_data(sec_firmware_img, ld_node_off,
 176                                        &data, &size)) {
 177                         printf("SEC Loadable: Can't get subimage data/size");
 178                         return -ENOENT;
 179                 }
 180
 181                 /* Get load address, treated as load offset to secure memory */
 182                 if (fit_image_get_load(sec_firmware_img, ld_node_off, &load)) {
 183                         printf("SEC Loadable: Can't get subimage load");
 184                         return -ENOENT;
 185                 }
 186
 187                 /* Compute load address for loadable in secure memory */
 188                 sec_firmware_loadable_addr = (sec_firmware_addr -
 189                                                 gd->arch.tlb_size) + load;
 190
 191                 /* Copy loadable to secure memory and flush dcache */
 192                 debug("%s copied to address 0x%p\n",
 193                       FIT_LOADABLE_PROP, (void *)sec_firmware_loadable_addr);
 194                 memcpy((void *)sec_firmware_loadable_addr, data, size);
 195                 flush_dcache_range(sec_firmware_loadable_addr,
 196                                    sec_firmware_loadable_addr + size);
 197
 198                 /* Populate loadable address only for Trusted OS */
 199                 if (!strcmp(str, "trustedOS@1")) {
 200                         /*
 201                          * Populate address ptrs for loadable image with
 202                          * loadbale addr
 203                          */
 204                         out_le32(loadable_l, (sec_firmware_loadable_addr &
 205                                               WORD_MASK));
 206                         out_le32(loadable_h, (sec_firmware_loadable_addr >>
 207                                               WORD_SHIFT));
 208                 }
 209         }
 210
 211         return 0;
 212 }
 213
 214 static int sec_firmware_copy_image(const char *title,
 215                          u64 image_addr, u32 image_size, u64 sec_firmware)
 216 {
 217         debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
 218         memcpy((void *)sec_firmware, (void *)image_addr, image_size);
 219         flush_dcache_range(sec_firmware, sec_firmware + image_size);
 220
 221         return 0;
 222 }
 223
 224 /*
 225  * This function will parse the SEC Firmware image, and then load it
 226  * to secure memory. Also load any loadable if present along with SEC
 227  * Firmware image.
 228  */
 229 static int sec_firmware_load_image(const void *sec_firmware_img,
 230                                    u32 *loadable_l, u32 *loadable_h)
 231 {
 232         const void *raw_image_addr;
 233         size_t raw_image_size = 0;
 234         int ret;
 235
 236         /*
 237          * The Excetpion Level must be EL3 to load and initialize
 238          * the SEC Firmware.
 239          */
 240         if (current_el() != 3) {
 241                 ret = -EACCES;
 242                 goto out;
 243         }
 244
 245 #ifdef CONFIG_SYS_MEM_RESERVE_SECURE
 246         /*
 247          * The SEC Firmware must be stored in secure memory.
 248          * Append SEC Firmware to secure mmu table.
 249          */
 250         if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
 251                 ret = -ENXIO;
 252                 goto out;
 253         }
 254
 255         sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
 256                         gd->arch.tlb_size;
 257 #else
 258 #error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
 259 #endif
 260
 261         /* Align SEC Firmware base address to 4K */
 262         sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
 263         debug("SEC Firmware: Load address: 0x%llx\n",
 264               sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
 265
 266         ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
 267                         &raw_image_size);
 268         if (ret)
 269                 goto out;
 270
 271         /* TODO:
 272          * Check if the end addr of SEC Firmware has been extend the secure
 273          * memory.
 274          */
 275
 276         /* Copy the secure firmware to secure memory */
 277         ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
 278                         raw_image_size, sec_firmware_addr &
 279                         SEC_FIRMWARE_ADDR_MASK);
 280         if (ret)
 281                 goto out;
 282
 283         /*
 284          * Check if any loadable are present along with firmware image, if
 285          * present load them.
 286          */
 287         ret = sec_firmware_check_copy_loadable(sec_firmware_img, loadable_l,
 288                                                loadable_h);
 289         if (ret)
 290                 goto out;
 291
 292         sec_firmware_addr |= SEC_FIRMWARE_LOADED;
 293         debug("SEC Firmware: Entry point: 0x%llx\n",
 294               sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
 295
 296         return 0;
 297
 298 out:
 299         printf("SEC Firmware: error (%d)\n", ret);
 300         sec_firmware_addr = 0;
 301
 302         return ret;
 303 }
 304
 305 static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
 306 {
 307         const void *entry = (void *)(sec_firmware_addr &
 308                                 SEC_FIRMWARE_ADDR_MASK);
 309
 310         return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
 311 }
 312
 313 /* Check the secure firmware FIT image */
 314 __weak bool sec_firmware_is_valid(const void *sec_firmware_img)
 315 {
 316         if (fdt_check_header(sec_firmware_img)) {
 317                 printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
 318                 return false;
 319         }
 320
 321         if (fit_check_format(sec_firmware_img, IMAGE_SIZE_INVAL)) {
 322                 printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
 323                 return false;
 324         }
 325
 326         return true;
 327 }
 328
 329 #ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
 330 /*
 331  * The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
 332  * v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
 333  * number will be returned according to SMC Calling Conventions. But
 334  * when getting the NOT_SUPPORTED error number, we cannot ensure if
 335  * the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
 336  * won't be supported by this framework.
 337  * And if the secure firmware isn't running, return NOT_SUPPORTED.
 338  *
 339  * The return value on success is PSCI version in format
 340  * major[31:16]:minor[15:0].
 341  */
 342 unsigned int sec_firmware_support_psci_version(void)
 343 {
 344         if (current_el() == SEC_FIRMWARE_TARGET_EL)
 345                 return _sec_firmware_support_psci_version();
 346
 347         return PSCI_INVALID_VER;
 348 }
 349 #endif
 350
 351 /*
 352  * Check with sec_firmware if it supports random number generation
 353  * via HW RNG
 354  *
 355  * The return value will be true if it is supported
 356  */
 357 bool sec_firmware_support_hwrng(void)
 358 {
 359 #ifdef CONFIG_TFABOOT
 360         /* return true as TFA has one job ring reserved */
 361         return true;
 362 #endif
 363         if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
 364                 return true;
 365         }
 366
 367         return false;
 368 }
 369
 370 /*
 371  * sec_firmware_get_random - Get a random number from SEC Firmware
 372  * @rand:               random number buffer to be filled
 373  * @bytes:              Number of bytes of random number to be supported
 374  * @eret:               -1 in case of error, 0 for success
 375  */
 376 int sec_firmware_get_random(uint8_t *rand, int bytes)
 377 {
 378         struct arm_smccc_res res;
 379         unsigned long long num;
 380         int param1;
 381
 382         if (!bytes || bytes > 8) {
 383                 printf("Max Random bytes genration supported is 8\n");
 384                 return -1;
 385         }
 386         if (bytes <= 4)
 387                 param1 = 0;
 388         else
 389                 param1 = 1;
 390
 391 #define SIP_RNG_64 0xC200FF11
 392         arm_smccc_smc(SIP_RNG_64, param1, 0, 0, 0, 0, 0, 0, &res);
 393         if (res.a0)
 394                 return -1;
 395
 396         num = res.a1;
 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         err = sec_firmware_get_random(rand, 8);
 474         if (err < 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 }