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