| 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* |
| 3 | * tboot.c: main implementation of helper functions used by kernel for |
| 4 | * runtime support of Intel(R) Trusted Execution Technology |
| 5 | * |
| 6 | * Copyright (c) 2006-2009, Intel Corporation |
| 7 | */ |
| 8 | |
| 9 | #include <linux/init_task.h> |
| 10 | #include <linux/spinlock.h> |
| 11 | #include <linux/export.h> |
| 12 | #include <linux/delay.h> |
| 13 | #include <linux/sched.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/dmar.h> |
| 16 | #include <linux/cpu.h> |
| 17 | #include <linux/pfn.h> |
| 18 | #include <linux/mm.h> |
| 19 | #include <linux/tboot.h> |
| 20 | #include <linux/debugfs.h> |
| 21 | |
| 22 | #include <asm/realmode.h> |
| 23 | #include <asm/processor.h> |
| 24 | #include <asm/bootparam.h> |
| 25 | #include <asm/pgalloc.h> |
| 26 | #include <asm/fixmap.h> |
| 27 | #include <asm/proto.h> |
| 28 | #include <asm/setup.h> |
| 29 | #include <asm/e820/api.h> |
| 30 | #include <asm/io.h> |
| 31 | |
| 32 | #include "../realmode/rm/wakeup.h" |
| 33 | |
| 34 | /* Global pointer to shared data; NULL means no measured launch. */ |
| 35 | static struct tboot *tboot __read_mostly; |
| 36 | |
| 37 | /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */ |
| 38 | #define AP_WAIT_TIMEOUT 1 |
| 39 | |
| 40 | #undef pr_fmt |
| 41 | #define pr_fmt(fmt) "tboot: " fmt |
| 42 | |
| 43 | static u8 tboot_uuid[16] __initdata = TBOOT_UUID; |
| 44 | |
| 45 | bool tboot_enabled(void) |
| 46 | { |
| 47 | return tboot != NULL; |
| 48 | } |
| 49 | |
| 50 | /* noinline to prevent gcc from warning about dereferencing constant fixaddr */ |
| 51 | static noinline __init bool check_tboot_version(void) |
| 52 | { |
| 53 | if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) { |
| 54 | pr_warn("tboot at 0x%llx is invalid\n", boot_params.tboot_addr); |
| 55 | return false; |
| 56 | } |
| 57 | |
| 58 | if (tboot->version < 5) { |
| 59 | pr_warn("tboot version is invalid: %u\n", tboot->version); |
| 60 | return false; |
| 61 | } |
| 62 | |
| 63 | pr_info("found shared page at phys addr 0x%llx:\n", |
| 64 | boot_params.tboot_addr); |
| 65 | pr_debug("version: %d\n", tboot->version); |
| 66 | pr_debug("log_addr: 0x%08x\n", tboot->log_addr); |
| 67 | pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry); |
| 68 | pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base); |
| 69 | pr_debug("tboot_size: 0x%x\n", tboot->tboot_size); |
| 70 | |
| 71 | return true; |
| 72 | } |
| 73 | |
| 74 | void __init tboot_probe(void) |
| 75 | { |
| 76 | /* Look for valid page-aligned address for shared page. */ |
| 77 | if (!boot_params.tboot_addr) |
| 78 | return; |
| 79 | /* |
| 80 | * also verify that it is mapped as we expect it before calling |
| 81 | * set_fixmap(), to reduce chance of garbage value causing crash |
| 82 | */ |
| 83 | if (!e820__mapped_any(boot_params.tboot_addr, |
| 84 | boot_params.tboot_addr, E820_TYPE_RESERVED)) { |
| 85 | pr_warn("non-0 tboot_addr but it is not of type E820_TYPE_RESERVED\n"); |
| 86 | return; |
| 87 | } |
| 88 | |
| 89 | /* Map and check for tboot UUID. */ |
| 90 | set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr); |
| 91 | tboot = (void *)fix_to_virt(FIX_TBOOT_BASE); |
| 92 | if (!check_tboot_version()) |
| 93 | tboot = NULL; |
| 94 | } |
| 95 | |
| 96 | static pgd_t *tboot_pg_dir; |
| 97 | static struct mm_struct tboot_mm = { |
| 98 | .mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, tboot_mm.mmap_lock), |
| 99 | .pgd = swapper_pg_dir, |
| 100 | .mm_users = ATOMIC_INIT(2), |
| 101 | .mm_count = ATOMIC_INIT(1), |
| 102 | .write_protect_seq = SEQCNT_ZERO(tboot_mm.write_protect_seq), |
| 103 | MMAP_LOCK_INITIALIZER(init_mm) |
| 104 | .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), |
| 105 | .mmlist = LIST_HEAD_INIT(init_mm.mmlist), |
| 106 | }; |
| 107 | |
| 108 | static inline void switch_to_tboot_pt(void) |
| 109 | { |
| 110 | write_cr3(virt_to_phys(tboot_pg_dir)); |
| 111 | } |
| 112 | |
| 113 | static int map_tboot_page(unsigned long vaddr, unsigned long pfn, |
| 114 | pgprot_t prot) |
| 115 | { |
| 116 | pgd_t *pgd; |
| 117 | p4d_t *p4d; |
| 118 | pud_t *pud; |
| 119 | pmd_t *pmd; |
| 120 | pte_t *pte; |
| 121 | |
| 122 | pgd = pgd_offset(&tboot_mm, vaddr); |
| 123 | p4d = p4d_alloc(&tboot_mm, pgd, vaddr); |
| 124 | if (!p4d) |
| 125 | return -1; |
| 126 | pud = pud_alloc(&tboot_mm, p4d, vaddr); |
| 127 | if (!pud) |
| 128 | return -1; |
| 129 | pmd = pmd_alloc(&tboot_mm, pud, vaddr); |
| 130 | if (!pmd) |
| 131 | return -1; |
| 132 | pte = pte_alloc_map(&tboot_mm, pmd, vaddr); |
| 133 | if (!pte) |
| 134 | return -1; |
| 135 | set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); |
| 136 | pte_unmap(pte); |
| 137 | |
| 138 | /* |
| 139 | * PTI poisons low addresses in the kernel page tables in the |
| 140 | * name of making them unusable for userspace. To execute |
| 141 | * code at such a low address, the poison must be cleared. |
| 142 | * |
| 143 | * Note: 'pgd' actually gets set in p4d_alloc() _or_ |
| 144 | * pud_alloc() depending on 4/5-level paging. |
| 145 | */ |
| 146 | pgd->pgd &= ~_PAGE_NX; |
| 147 | |
| 148 | return 0; |
| 149 | } |
| 150 | |
| 151 | static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, |
| 152 | unsigned long nr) |
| 153 | { |
| 154 | /* Reuse the original kernel mapping */ |
| 155 | tboot_pg_dir = pgd_alloc(&tboot_mm); |
| 156 | if (!tboot_pg_dir) |
| 157 | return -1; |
| 158 | |
| 159 | for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { |
| 160 | if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC)) |
| 161 | return -1; |
| 162 | } |
| 163 | |
| 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | static void tboot_create_trampoline(void) |
| 168 | { |
| 169 | u32 map_base, map_size; |
| 170 | |
| 171 | /* Create identity map for tboot shutdown code. */ |
| 172 | map_base = PFN_DOWN(tboot->tboot_base); |
| 173 | map_size = PFN_UP(tboot->tboot_size); |
| 174 | if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size)) |
| 175 | panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", |
| 176 | map_base, map_size); |
| 177 | } |
| 178 | |
| 179 | #ifdef CONFIG_ACPI_SLEEP |
| 180 | |
| 181 | static void add_mac_region(phys_addr_t start, unsigned long size) |
| 182 | { |
| 183 | struct tboot_mac_region *mr; |
| 184 | phys_addr_t end = start + size; |
| 185 | |
| 186 | if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS) |
| 187 | panic("tboot: Too many MAC regions\n"); |
| 188 | |
| 189 | if (start && size) { |
| 190 | mr = &tboot->mac_regions[tboot->num_mac_regions++]; |
| 191 | mr->start = round_down(start, PAGE_SIZE); |
| 192 | mr->size = round_up(end, PAGE_SIZE) - mr->start; |
| 193 | } |
| 194 | } |
| 195 | |
| 196 | static int tboot_setup_sleep(void) |
| 197 | { |
| 198 | int i; |
| 199 | |
| 200 | tboot->num_mac_regions = 0; |
| 201 | |
| 202 | for (i = 0; i < e820_table->nr_entries; i++) { |
| 203 | if (e820_table->entries[i].type != E820_TYPE_RAM) |
| 204 | continue; |
| 205 | |
| 206 | add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size); |
| 207 | } |
| 208 | |
| 209 | tboot->acpi_sinfo.kernel_s3_resume_vector = |
| 210 | real_mode_header->wakeup_start; |
| 211 | |
| 212 | return 0; |
| 213 | } |
| 214 | |
| 215 | #else /* no CONFIG_ACPI_SLEEP */ |
| 216 | |
| 217 | static int tboot_setup_sleep(void) |
| 218 | { |
| 219 | /* S3 shutdown requested, but S3 not supported by the kernel... */ |
| 220 | BUG(); |
| 221 | return -1; |
| 222 | } |
| 223 | |
| 224 | #endif |
| 225 | |
| 226 | void tboot_shutdown(u32 shutdown_type) |
| 227 | { |
| 228 | void (*shutdown)(void); |
| 229 | |
| 230 | if (!tboot_enabled()) |
| 231 | return; |
| 232 | |
| 233 | /* |
| 234 | * if we're being called before the 1:1 mapping is set up then just |
| 235 | * return and let the normal shutdown happen; this should only be |
| 236 | * due to very early panic() |
| 237 | */ |
| 238 | if (!tboot_pg_dir) |
| 239 | return; |
| 240 | |
| 241 | /* if this is S3 then set regions to MAC */ |
| 242 | if (shutdown_type == TB_SHUTDOWN_S3) |
| 243 | if (tboot_setup_sleep()) |
| 244 | return; |
| 245 | |
| 246 | tboot->shutdown_type = shutdown_type; |
| 247 | |
| 248 | switch_to_tboot_pt(); |
| 249 | |
| 250 | shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; |
| 251 | shutdown(); |
| 252 | |
| 253 | /* should not reach here */ |
| 254 | while (1) |
| 255 | halt(); |
| 256 | } |
| 257 | |
| 258 | static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) |
| 259 | { |
| 260 | #define TB_COPY_GAS(tbg, g) \ |
| 261 | tbg.space_id = g.space_id; \ |
| 262 | tbg.bit_width = g.bit_width; \ |
| 263 | tbg.bit_offset = g.bit_offset; \ |
| 264 | tbg.access_width = g.access_width; \ |
| 265 | tbg.address = g.address; |
| 266 | |
| 267 | TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); |
| 268 | TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); |
| 269 | TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); |
| 270 | TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); |
| 271 | |
| 272 | /* |
| 273 | * We need phys addr of waking vector, but can't use virt_to_phys() on |
| 274 | * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys |
| 275 | * addr. |
| 276 | */ |
| 277 | tboot->acpi_sinfo.wakeup_vector = fadt->facs + |
| 278 | offsetof(struct acpi_table_facs, firmware_waking_vector); |
| 279 | } |
| 280 | |
| 281 | static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) |
| 282 | { |
| 283 | static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { |
| 284 | /* S0,1,2: */ -1, -1, -1, |
| 285 | /* S3: */ TB_SHUTDOWN_S3, |
| 286 | /* S4: */ TB_SHUTDOWN_S4, |
| 287 | /* S5: */ TB_SHUTDOWN_S5 }; |
| 288 | |
| 289 | if (!tboot_enabled()) |
| 290 | return 0; |
| 291 | |
| 292 | tboot_copy_fadt(&acpi_gbl_FADT); |
| 293 | tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; |
| 294 | tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; |
| 295 | /* we always use the 32b wakeup vector */ |
| 296 | tboot->acpi_sinfo.vector_width = 32; |
| 297 | |
| 298 | if (sleep_state >= ACPI_S_STATE_COUNT || |
| 299 | acpi_shutdown_map[sleep_state] == -1) { |
| 300 | pr_warn("unsupported sleep state 0x%x\n", sleep_state); |
| 301 | return -1; |
| 302 | } |
| 303 | |
| 304 | tboot_shutdown(acpi_shutdown_map[sleep_state]); |
| 305 | return 0; |
| 306 | } |
| 307 | |
| 308 | static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b) |
| 309 | { |
| 310 | if (!tboot_enabled()) |
| 311 | return 0; |
| 312 | |
| 313 | pr_warn("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)"); |
| 314 | return -ENODEV; |
| 315 | } |
| 316 | |
| 317 | static atomic_t ap_wfs_count; |
| 318 | |
| 319 | static int tboot_wait_for_aps(int num_aps) |
| 320 | { |
| 321 | unsigned long timeout; |
| 322 | |
| 323 | timeout = AP_WAIT_TIMEOUT*HZ; |
| 324 | while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps && |
| 325 | timeout) { |
| 326 | mdelay(1); |
| 327 | timeout--; |
| 328 | } |
| 329 | |
| 330 | if (timeout) |
| 331 | pr_warn("tboot wait for APs timeout\n"); |
| 332 | |
| 333 | return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps); |
| 334 | } |
| 335 | |
| 336 | static int tboot_dying_cpu(unsigned int cpu) |
| 337 | { |
| 338 | atomic_inc(&ap_wfs_count); |
| 339 | if (num_online_cpus() == 1) { |
| 340 | if (tboot_wait_for_aps(atomic_read(&ap_wfs_count))) |
| 341 | return -EBUSY; |
| 342 | } |
| 343 | return 0; |
| 344 | } |
| 345 | |
| 346 | #ifdef CONFIG_DEBUG_FS |
| 347 | |
| 348 | #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ |
| 349 | 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } |
| 350 | |
| 351 | #define TBOOT_SERIAL_LOG_ADDR 0x60000 |
| 352 | #define TBOOT_SERIAL_LOG_SIZE 0x08000 |
| 353 | #define LOG_MAX_SIZE_OFF 16 |
| 354 | #define LOG_BUF_OFF 24 |
| 355 | |
| 356 | static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; |
| 357 | |
| 358 | static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) |
| 359 | { |
| 360 | void __iomem *log_base; |
| 361 | u8 log_uuid[16]; |
| 362 | u32 max_size; |
| 363 | void *kbuf; |
| 364 | int ret = -EFAULT; |
| 365 | |
| 366 | log_base = ioremap(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); |
| 367 | if (!log_base) |
| 368 | return ret; |
| 369 | |
| 370 | memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); |
| 371 | if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid))) |
| 372 | goto err_iounmap; |
| 373 | |
| 374 | max_size = readl(log_base + LOG_MAX_SIZE_OFF); |
| 375 | if (*ppos >= max_size) { |
| 376 | ret = 0; |
| 377 | goto err_iounmap; |
| 378 | } |
| 379 | |
| 380 | if (*ppos + count > max_size) |
| 381 | count = max_size - *ppos; |
| 382 | |
| 383 | kbuf = kmalloc(count, GFP_KERNEL); |
| 384 | if (!kbuf) { |
| 385 | ret = -ENOMEM; |
| 386 | goto err_iounmap; |
| 387 | } |
| 388 | |
| 389 | memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); |
| 390 | if (copy_to_user(user_buf, kbuf, count)) |
| 391 | goto err_kfree; |
| 392 | |
| 393 | *ppos += count; |
| 394 | |
| 395 | ret = count; |
| 396 | |
| 397 | err_kfree: |
| 398 | kfree(kbuf); |
| 399 | |
| 400 | err_iounmap: |
| 401 | iounmap(log_base); |
| 402 | |
| 403 | return ret; |
| 404 | } |
| 405 | |
| 406 | static const struct file_operations tboot_log_fops = { |
| 407 | .read = tboot_log_read, |
| 408 | .llseek = default_llseek, |
| 409 | }; |
| 410 | |
| 411 | #endif /* CONFIG_DEBUG_FS */ |
| 412 | |
| 413 | static __init int tboot_late_init(void) |
| 414 | { |
| 415 | if (!tboot_enabled()) |
| 416 | return 0; |
| 417 | |
| 418 | tboot_create_trampoline(); |
| 419 | |
| 420 | atomic_set(&ap_wfs_count, 0); |
| 421 | cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL, |
| 422 | tboot_dying_cpu); |
| 423 | #ifdef CONFIG_DEBUG_FS |
| 424 | debugfs_create_file("tboot_log", S_IRUSR, |
| 425 | arch_debugfs_dir, NULL, &tboot_log_fops); |
| 426 | #endif |
| 427 | |
| 428 | acpi_os_set_prepare_sleep(&tboot_sleep); |
| 429 | acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep); |
| 430 | return 0; |
| 431 | } |
| 432 | |
| 433 | late_initcall(tboot_late_init); |
| 434 | |
| 435 | /* |
| 436 | * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) |
| 437 | */ |
| 438 | |
| 439 | #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 |
| 440 | #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 |
| 441 | |
| 442 | /* # pages for each config regs space - used by fixmap */ |
| 443 | #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ |
| 444 | TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) |
| 445 | |
| 446 | /* offsets from pub/priv config space */ |
| 447 | #define TXTCR_HEAP_BASE 0x0300 |
| 448 | #define TXTCR_HEAP_SIZE 0x0308 |
| 449 | |
| 450 | #define SHA1_SIZE 20 |
| 451 | |
| 452 | struct sha1_hash { |
| 453 | u8 hash[SHA1_SIZE]; |
| 454 | }; |
| 455 | |
| 456 | struct sinit_mle_data { |
| 457 | u32 version; /* currently 6 */ |
| 458 | struct sha1_hash bios_acm_id; |
| 459 | u32 edx_senter_flags; |
| 460 | u64 mseg_valid; |
| 461 | struct sha1_hash sinit_hash; |
| 462 | struct sha1_hash mle_hash; |
| 463 | struct sha1_hash stm_hash; |
| 464 | struct sha1_hash lcp_policy_hash; |
| 465 | u32 lcp_policy_control; |
| 466 | u32 rlp_wakeup_addr; |
| 467 | u32 reserved; |
| 468 | u32 num_mdrs; |
| 469 | u32 mdrs_off; |
| 470 | u32 num_vtd_dmars; |
| 471 | u32 vtd_dmars_off; |
| 472 | } __packed; |
| 473 | |
| 474 | struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) |
| 475 | { |
| 476 | void *heap_base, *heap_ptr, *config; |
| 477 | |
| 478 | if (!tboot_enabled()) |
| 479 | return dmar_tbl; |
| 480 | |
| 481 | /* |
| 482 | * ACPI tables may not be DMA protected by tboot, so use DMAR copy |
| 483 | * SINIT saved in SinitMleData in TXT heap (which is DMA protected) |
| 484 | */ |
| 485 | |
| 486 | /* map config space in order to get heap addr */ |
| 487 | config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * |
| 488 | PAGE_SIZE); |
| 489 | if (!config) |
| 490 | return NULL; |
| 491 | |
| 492 | /* now map TXT heap */ |
| 493 | heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), |
| 494 | *(u64 *)(config + TXTCR_HEAP_SIZE)); |
| 495 | iounmap(config); |
| 496 | if (!heap_base) |
| 497 | return NULL; |
| 498 | |
| 499 | /* walk heap to SinitMleData */ |
| 500 | /* skip BiosData */ |
| 501 | heap_ptr = heap_base + *(u64 *)heap_base; |
| 502 | /* skip OsMleData */ |
| 503 | heap_ptr += *(u64 *)heap_ptr; |
| 504 | /* skip OsSinitData */ |
| 505 | heap_ptr += *(u64 *)heap_ptr; |
| 506 | /* now points to SinitMleDataSize; set to SinitMleData */ |
| 507 | heap_ptr += sizeof(u64); |
| 508 | /* get addr of DMAR table */ |
| 509 | dmar_tbl = (struct acpi_table_header *)(heap_ptr + |
| 510 | ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - |
| 511 | sizeof(u64)); |
| 512 | |
| 513 | /* don't unmap heap because dmar.c needs access to this */ |
| 514 | |
| 515 | return dmar_tbl; |
| 516 | } |