arch/arm/cpu/armv8/sec_firmware.c

   1 /*
   2  * Copyright 2016 NXP Semiconductor, Inc.
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <errno.h>
   9 #include <linux/kernel.h>
  10 #include <asm/io.h>
  11 #include <asm/system.h>
  12 #include <asm/types.h>
  13 #include <asm/macro.h>
  14 #include <asm/armv8/sec_firmware.h>
  15
  16 DECLARE_GLOBAL_DATA_PTR;
  17 extern void c_runtime_cpu_setup(void);
  18
  19 #define SEC_FIRMWARE_LOADED     0x1
  20 #define SEC_FIRMWARE_RUNNING    0x2
  21 #define SEC_FIRMWARE_ADDR_MASK  (~0x3)
  22 /*
  23  * Secure firmware load addr
  24  * Flags used: 0x1 secure firmware has been loaded to secure memory
  25  *             0x2 secure firmware is running
  26  */
  27 phys_addr_t sec_firmware_addr;
  28
  29 #ifndef SEC_FIRMWARE_FIT_IMAGE
  30 #define SEC_FIRMWARE_FIT_IMAGE          "firmware"
  31 #endif
  32 #ifndef SEC_FIRMEWARE_FIT_CNF_NAME
  33 #define SEC_FIRMEWARE_FIT_CNF_NAME      "config@1"
  34 #endif
  35 #ifndef SEC_FIRMWARE_TARGET_EL
  36 #define SEC_FIRMWARE_TARGET_EL          2
  37 #endif
  38
  39 static int sec_firmware_get_data(const void *sec_firmware_img,
  40                                 const void **data, size_t *size)
  41 {
  42         int conf_node_off, fw_node_off;
  43         char *conf_node_name = NULL;
  44         char *desc;
  45         int ret;
  46
  47         conf_node_name = SEC_FIRMEWARE_FIT_CNF_NAME;
  48
  49         conf_node_off = fit_conf_get_node(sec_firmware_img, conf_node_name);
  50         if (conf_node_off < 0) {
  51                 printf("SEC Firmware: %s: no such config\n", conf_node_name);
  52                 return -ENOENT;
  53         }
  54
  55         fw_node_off = fit_conf_get_prop_node(sec_firmware_img, conf_node_off,
  56                         SEC_FIRMWARE_FIT_IMAGE);
  57         if (fw_node_off < 0) {
  58                 printf("SEC Firmware: No '%s' in config\n",
  59                        SEC_FIRMWARE_FIT_IMAGE);
  60                 return -ENOLINK;
  61         }
  62
  63         /* Verify secure firmware image */
  64         if (!(fit_image_verify(sec_firmware_img, fw_node_off))) {
  65                 printf("SEC Firmware: Bad firmware image (bad CRC)\n");
  66                 return -EINVAL;
  67         }
  68
  69         if (fit_image_get_data(sec_firmware_img, fw_node_off, data, size)) {
  70                 printf("SEC Firmware: Can't get %s subimage data/size",
  71                        SEC_FIRMWARE_FIT_IMAGE);
  72                 return -ENOENT;
  73         }
  74
  75         ret = fit_get_desc(sec_firmware_img, fw_node_off, &desc);
  76         if (ret)
  77                 printf("SEC Firmware: Can't get description\n");
  78         else
  79                 printf("%s\n", desc);
  80
  81         return ret;
  82 }
  83
  84 /*
  85  * SEC Firmware FIT image parser checks if the image is in FIT
  86  * format, verifies integrity of the image and calculates raw
  87  * image address and size values.
  88  *
  89  * Returns 0 on success and a negative errno on error task fail.
  90  */
  91 static int sec_firmware_parse_image(const void *sec_firmware_img,
  92                                         const void **raw_image_addr,
  93                                         size_t *raw_image_size)
  94 {
  95         int ret;
  96
  97         ret = sec_firmware_get_data(sec_firmware_img, raw_image_addr,
  98                                         raw_image_size);
  99         if (ret)
 100                 return ret;
 101
 102         debug("SEC Firmware: raw_image_addr = 0x%p, raw_image_size = 0x%lx\n",
 103               *raw_image_addr, *raw_image_size);
 104
 105         return 0;
 106 }
 107
 108 static int sec_firmware_copy_image(const char *title,
 109                          u64 image_addr, u32 image_size, u64 sec_firmware)
 110 {
 111         debug("%s copied to address 0x%p\n", title, (void *)sec_firmware);
 112         memcpy((void *)sec_firmware, (void *)image_addr, image_size);
 113         flush_dcache_range(sec_firmware, sec_firmware + image_size);
 114
 115         return 0;
 116 }
 117
 118 /*
 119  * This function will parse the SEC Firmware image, and then load it
 120  * to secure memory.
 121  */
 122 static int sec_firmware_load_image(const void *sec_firmware_img)
 123 {
 124         const void *raw_image_addr;
 125         size_t raw_image_size = 0;
 126         int ret;
 127
 128         /*
 129          * The Excetpion Level must be EL3 to load and initialize
 130          * the SEC Firmware.
 131          */
 132         if (current_el() != 3) {
 133                 ret = -EACCES;
 134                 goto out;
 135         }
 136
 137 #ifdef CONFIG_SYS_MEM_RESERVE_SECURE
 138         /*
 139          * The SEC Firmware must be stored in secure memory.
 140          * Append SEC Firmware to secure mmu table.
 141          */
 142         if (!(gd->arch.secure_ram & MEM_RESERVE_SECURE_MAINTAINED)) {
 143                 ret = -ENXIO;
 144                 goto out;
 145         }
 146
 147         sec_firmware_addr = (gd->arch.secure_ram & MEM_RESERVE_SECURE_ADDR_MASK) +
 148                         gd->arch.tlb_size;
 149 #else
 150 #error "The CONFIG_SYS_MEM_RESERVE_SECURE must be defined when enabled SEC Firmware support"
 151 #endif
 152
 153         /* Align SEC Firmware base address to 4K */
 154         sec_firmware_addr = (sec_firmware_addr + 0xfff) & ~0xfff;
 155         debug("SEC Firmware: Load address: 0x%llx\n",
 156               sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
 157
 158         ret = sec_firmware_parse_image(sec_firmware_img, &raw_image_addr,
 159                         &raw_image_size);
 160         if (ret)
 161                 goto out;
 162
 163         /* TODO:
 164          * Check if the end addr of SEC Firmware has been extend the secure
 165          * memory.
 166          */
 167
 168         /* Copy the secure firmware to secure memory */
 169         ret = sec_firmware_copy_image("SEC Firmware", (u64)raw_image_addr,
 170                         raw_image_size, sec_firmware_addr &
 171                         SEC_FIRMWARE_ADDR_MASK);
 172         if (ret)
 173                 goto out;
 174
 175         sec_firmware_addr |= SEC_FIRMWARE_LOADED;
 176         debug("SEC Firmware: Entry point: 0x%llx\n",
 177               sec_firmware_addr & SEC_FIRMWARE_ADDR_MASK);
 178
 179         return 0;
 180
 181 out:
 182         printf("SEC Firmware: error (%d)\n", ret);
 183         sec_firmware_addr = 0;
 184
 185         return ret;
 186 }
 187
 188 static int sec_firmware_entry(u32 *eret_hold_l, u32 *eret_hold_h)
 189 {
 190         const void *entry = (void *)(sec_firmware_addr &
 191                                 SEC_FIRMWARE_ADDR_MASK);
 192
 193         return _sec_firmware_entry(entry, eret_hold_l, eret_hold_h);
 194 }
 195
 196 /* Check the secure firmware FIT image */
 197 __weak bool sec_firmware_is_valid(const void *sec_firmware_img)
 198 {
 199         if (fdt_check_header(sec_firmware_img)) {
 200                 printf("SEC Firmware: Bad firmware image (not a FIT image)\n");
 201                 return false;
 202         }
 203
 204         if (!fit_check_format(sec_firmware_img)) {
 205                 printf("SEC Firmware: Bad firmware image (bad FIT header)\n");
 206                 return false;
 207         }
 208
 209         return true;
 210 }
 211
 212 #ifdef CONFIG_SEC_FIRMWARE_ARMV8_PSCI
 213 /*
 214  * The PSCI_VERSION function is added from PSCI v0.2. When the PSCI
 215  * v0.1 received this function, the NOT_SUPPORTED (0xffff_ffff) error
 216  * number will be returned according to SMC Calling Conventions. But
 217  * when getting the NOT_SUPPORTED error number, we cannot ensure if
 218  * the PSCI version is v0.1 or other error occurred. So, PSCI v0.1
 219  * won't be supported by this framework.
 220  * And if the secure firmware isn't running, return NOT_SUPPORTED.
 221  *
 222  * The return value on success is PSCI version in format
 223  * major[31:16]:minor[15:0].
 224  */
 225 unsigned int sec_firmware_support_psci_version(void)
 226 {
 227         if (current_el() == SEC_FIRMWARE_TARGET_EL)
 228                 return _sec_firmware_support_psci_version();
 229
 230         return PSCI_INVALID_VER;
 231 }
 232 #endif
 233
 234 /*
 235  * Check with sec_firmware if it supports random number generation
 236  * via HW RNG
 237  *
 238  * The return value will be true if it is supported
 239  */
 240 bool sec_firmware_support_hwrng(void)
 241 {
 242         uint8_t rand[8];
 243         if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) {
 244                 if (!sec_firmware_get_random(rand, 8))
 245                         return true;
 246         }
 247
 248         return false;
 249 }
 250
 251 /*
 252  * sec_firmware_get_random - Get a random number from SEC Firmware
 253  * @rand:               random number buffer to be filled
 254  * @bytes:              Number of bytes of random number to be supported
 255  * @eret:               -1 in case of error, 0 for success
 256  */
 257 int sec_firmware_get_random(uint8_t *rand, int bytes)
 258 {
 259         unsigned long long num;
 260         struct pt_regs regs;
 261         int param1;
 262
 263         if (!bytes || bytes > 8) {
 264                 printf("Max Random bytes genration supported is 8\n");
 265                 return -1;
 266         }
 267 #define SIP_RNG_64 0xC200FF11
 268         regs.regs[0] = SIP_RNG_64;
 269
 270         if (bytes <= 4)
 271                 param1 = 0;
 272         else
 273                 param1 = 1;
 274         regs.regs[1] = param1;
 275
 276         smc_call(&regs);
 277
 278         if (regs.regs[0])
 279                 return -1;
 280
 281         num = regs.regs[1];
 282         memcpy(rand, &num, bytes);
 283
 284         return 0;
 285 }
 286
 287 /*
 288  * sec_firmware_init - Initialize the SEC Firmware
 289  * @sec_firmware_img:   the SEC Firmware image address
 290  * @eret_hold_l:        the address to hold exception return address low
 291  * @eret_hold_h:        the address to hold exception return address high
 292  */
 293 int sec_firmware_init(const void *sec_firmware_img,
 294                         u32 *eret_hold_l,
 295                         u32 *eret_hold_h)
 296 {
 297         int ret;
 298
 299         if (!sec_firmware_is_valid(sec_firmware_img))
 300                 return -EINVAL;
 301
 302         ret = sec_firmware_load_image(sec_firmware_img);
 303         if (ret) {
 304                 printf("SEC Firmware: Failed to load image\n");
 305                 return ret;
 306         } else if (sec_firmware_addr & SEC_FIRMWARE_LOADED) {
 307                 ret = sec_firmware_entry(eret_hold_l, eret_hold_h);
 308                 if (ret) {
 309                         printf("SEC Firmware: Failed to initialize\n");
 310                         return ret;
 311                 }
 312         }
 313
 314         debug("SEC Firmware: Return from SEC Firmware: current_el = %d\n",
 315               current_el());
 316
 317         /*
 318          * The PE will be turned into target EL when returned from
 319          * SEC Firmware.
 320          */
 321         if (current_el() != SEC_FIRMWARE_TARGET_EL)
 322                 return -EACCES;
 323
 324         sec_firmware_addr |= SEC_FIRMWARE_RUNNING;
 325
 326         /* Set exception table and enable caches if it isn't EL3 */
 327         if (current_el() != 3) {
 328                 c_runtime_cpu_setup();
 329                 enable_caches();
 330         }
 331
 332         return 0;
 333 }
 334
 335 /*
 336  * fdt_fix_kaslr - Add kalsr-seed node in Device tree
 337  * @fdt:                Device tree
 338  * @eret:               0 in case of error, 1 for success
 339  */
 340 int fdt_fixup_kaslr(void *fdt)
 341 {
 342         int nodeoffset;
 343         int err, ret = 0;
 344         u8 rand[8];
 345
 346 #if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
 347         /* Check if random seed generation is  supported */
 348         if (sec_firmware_support_hwrng() == false)
 349                 return 0;
 350
 351         ret = sec_firmware_get_random(rand, 8);
 352         if (ret < 0) {
 353                 printf("WARNING: No random number to set kaslr-seed\n");
 354                 return 0;
 355         }
 356
 357         err = fdt_check_header(fdt);
 358         if (err < 0) {
 359                 printf("fdt_chosen: %s\n", fdt_strerror(err));
 360                 return 0;
 361         }
 362
 363         /* find or create "/chosen" node. */
 364         nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
 365         if (nodeoffset < 0)
 366                 return 0;
 367
 368         err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
 369                                   sizeof(rand));
 370         if (err < 0) {
 371                 printf("WARNING: can't set kaslr-seed %s.\n",
 372                        fdt_strerror(err));
 373                 return 0;
 374         }
 375         ret = 1;
 376 #endif
 377
 378         return ret;
 379 }