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