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 && (e820_table->entries[i].type != E820_TYPE_RESERVED_KERN)) 205 continue; 206 207 add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size); 208 } 209 210 tboot->acpi_sinfo.kernel_s3_resume_vector = 211 real_mode_header->wakeup_start; 212 213 return 0; 214 } 215 216 #else /* no CONFIG_ACPI_SLEEP */ 217 218 static int tboot_setup_sleep(void) 219 { 220 /* S3 shutdown requested, but S3 not supported by the kernel... */ 221 BUG(); 222 return -1; 223 } 224 225 #endif 226 227 void tboot_shutdown(u32 shutdown_type) 228 { 229 void (*shutdown)(void); 230 231 if (!tboot_enabled()) 232 return; 233 234 /* 235 * if we're being called before the 1:1 mapping is set up then just 236 * return and let the normal shutdown happen; this should only be 237 * due to very early panic() 238 */ 239 if (!tboot_pg_dir) 240 return; 241 242 /* if this is S3 then set regions to MAC */ 243 if (shutdown_type == TB_SHUTDOWN_S3) 244 if (tboot_setup_sleep()) 245 return; 246 247 tboot->shutdown_type = shutdown_type; 248 249 switch_to_tboot_pt(); 250 251 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; 252 shutdown(); 253 254 /* should not reach here */ 255 while (1) 256 halt(); 257 } 258 259 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) 260 { 261 #define TB_COPY_GAS(tbg, g) \ 262 tbg.space_id = g.space_id; \ 263 tbg.bit_width = g.bit_width; \ 264 tbg.bit_offset = g.bit_offset; \ 265 tbg.access_width = g.access_width; \ 266 tbg.address = g.address; 267 268 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); 269 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); 270 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); 271 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); 272 273 /* 274 * We need phys addr of waking vector, but can't use virt_to_phys() on 275 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys 276 * addr. 277 */ 278 tboot->acpi_sinfo.wakeup_vector = fadt->facs + 279 offsetof(struct acpi_table_facs, firmware_waking_vector); 280 } 281 282 static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) 283 { 284 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { 285 /* S0,1,2: */ -1, -1, -1, 286 /* S3: */ TB_SHUTDOWN_S3, 287 /* S4: */ TB_SHUTDOWN_S4, 288 /* S5: */ TB_SHUTDOWN_S5 }; 289 290 if (!tboot_enabled()) 291 return 0; 292 293 tboot_copy_fadt(&acpi_gbl_FADT); 294 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; 295 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; 296 /* we always use the 32b wakeup vector */ 297 tboot->acpi_sinfo.vector_width = 32; 298 299 if (sleep_state >= ACPI_S_STATE_COUNT || 300 acpi_shutdown_map[sleep_state] == -1) { 301 pr_warn("unsupported sleep state 0x%x\n", sleep_state); 302 return -1; 303 } 304 305 tboot_shutdown(acpi_shutdown_map[sleep_state]); 306 return 0; 307 } 308 309 static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b) 310 { 311 if (!tboot_enabled()) 312 return 0; 313 314 pr_warn("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)"); 315 return -ENODEV; 316 } 317 318 static atomic_t ap_wfs_count; 319 320 static int tboot_wait_for_aps(int num_aps) 321 { 322 unsigned long timeout; 323 324 timeout = AP_WAIT_TIMEOUT*HZ; 325 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps && 326 timeout) { 327 mdelay(1); 328 timeout--; 329 } 330 331 if (timeout) 332 pr_warn("tboot wait for APs timeout\n"); 333 334 return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps); 335 } 336 337 static int tboot_dying_cpu(unsigned int cpu) 338 { 339 atomic_inc(&ap_wfs_count); 340 if (num_online_cpus() == 1) { 341 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count))) 342 return -EBUSY; 343 } 344 return 0; 345 } 346 347 #ifdef CONFIG_DEBUG_FS 348 349 #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ 350 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } 351 352 #define TBOOT_SERIAL_LOG_ADDR 0x60000 353 #define TBOOT_SERIAL_LOG_SIZE 0x08000 354 #define LOG_MAX_SIZE_OFF 16 355 #define LOG_BUF_OFF 24 356 357 static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; 358 359 static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) 360 { 361 void __iomem *log_base; 362 u8 log_uuid[16]; 363 u32 max_size; 364 void *kbuf; 365 int ret = -EFAULT; 366 367 log_base = ioremap(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); 368 if (!log_base) 369 return ret; 370 371 memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); 372 if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid))) 373 goto err_iounmap; 374 375 max_size = readl(log_base + LOG_MAX_SIZE_OFF); 376 if (*ppos >= max_size) { 377 ret = 0; 378 goto err_iounmap; 379 } 380 381 if (*ppos + count > max_size) 382 count = max_size - *ppos; 383 384 kbuf = kmalloc(count, GFP_KERNEL); 385 if (!kbuf) { 386 ret = -ENOMEM; 387 goto err_iounmap; 388 } 389 390 memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); 391 if (copy_to_user(user_buf, kbuf, count)) 392 goto err_kfree; 393 394 *ppos += count; 395 396 ret = count; 397 398 err_kfree: 399 kfree(kbuf); 400 401 err_iounmap: 402 iounmap(log_base); 403 404 return ret; 405 } 406 407 static const struct file_operations tboot_log_fops = { 408 .read = tboot_log_read, 409 .llseek = default_llseek, 410 }; 411 412 #endif /* CONFIG_DEBUG_FS */ 413 414 static __init int tboot_late_init(void) 415 { 416 if (!tboot_enabled()) 417 return 0; 418 419 tboot_create_trampoline(); 420 421 atomic_set(&ap_wfs_count, 0); 422 cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL, 423 tboot_dying_cpu); 424 #ifdef CONFIG_DEBUG_FS 425 debugfs_create_file("tboot_log", S_IRUSR, 426 arch_debugfs_dir, NULL, &tboot_log_fops); 427 #endif 428 429 acpi_os_set_prepare_sleep(&tboot_sleep); 430 acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep); 431 return 0; 432 } 433 434 late_initcall(tboot_late_init); 435 436 /* 437 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) 438 */ 439 440 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 441 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 442 443 /* # pages for each config regs space - used by fixmap */ 444 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ 445 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) 446 447 /* offsets from pub/priv config space */ 448 #define TXTCR_HEAP_BASE 0x0300 449 #define TXTCR_HEAP_SIZE 0x0308 450 451 #define SHA1_SIZE 20 452 453 struct sha1_hash { 454 u8 hash[SHA1_SIZE]; 455 }; 456 457 struct sinit_mle_data { 458 u32 version; /* currently 6 */ 459 struct sha1_hash bios_acm_id; 460 u32 edx_senter_flags; 461 u64 mseg_valid; 462 struct sha1_hash sinit_hash; 463 struct sha1_hash mle_hash; 464 struct sha1_hash stm_hash; 465 struct sha1_hash lcp_policy_hash; 466 u32 lcp_policy_control; 467 u32 rlp_wakeup_addr; 468 u32 reserved; 469 u32 num_mdrs; 470 u32 mdrs_off; 471 u32 num_vtd_dmars; 472 u32 vtd_dmars_off; 473 } __packed; 474 475 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) 476 { 477 void *heap_base, *heap_ptr, *config; 478 479 if (!tboot_enabled()) 480 return dmar_tbl; 481 482 /* 483 * ACPI tables may not be DMA protected by tboot, so use DMAR copy 484 * SINIT saved in SinitMleData in TXT heap (which is DMA protected) 485 */ 486 487 /* map config space in order to get heap addr */ 488 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * 489 PAGE_SIZE); 490 if (!config) 491 return NULL; 492 493 /* now map TXT heap */ 494 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), 495 *(u64 *)(config + TXTCR_HEAP_SIZE)); 496 iounmap(config); 497 if (!heap_base) 498 return NULL; 499 500 /* walk heap to SinitMleData */ 501 /* skip BiosData */ 502 heap_ptr = heap_base + *(u64 *)heap_base; 503 /* skip OsMleData */ 504 heap_ptr += *(u64 *)heap_ptr; 505 /* skip OsSinitData */ 506 heap_ptr += *(u64 *)heap_ptr; 507 /* now points to SinitMleDataSize; set to SinitMleData */ 508 heap_ptr += sizeof(u64); 509 /* get addr of DMAR table */ 510 dmar_tbl = (struct acpi_table_header *)(heap_ptr + 511 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - 512 sizeof(u64)); 513 514 /* don't unmap heap because dmar.c needs access to this */ 515 516 return dmar_tbl; 517 } 518