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/intel-iommu.h> 10 #include <linux/init_task.h> 11 #include <linux/spinlock.h> 12 #include <linux/export.h> 13 #include <linux/delay.h> 14 #include <linux/sched.h> 15 #include <linux/init.h> 16 #include <linux/dmar.h> 17 #include <linux/cpu.h> 18 #include <linux/pfn.h> 19 #include <linux/mm.h> 20 #include <linux/tboot.h> 21 #include <linux/debugfs.h> 22 23 #include <asm/realmode.h> 24 #include <asm/processor.h> 25 #include <asm/bootparam.h> 26 #include <asm/pgtable.h> 27 #include <asm/pgalloc.h> 28 #include <asm/swiotlb.h> 29 #include <asm/fixmap.h> 30 #include <asm/proto.h> 31 #include <asm/setup.h> 32 #include <asm/e820/api.h> 33 #include <asm/io.h> 34 35 #include "../realmode/rm/wakeup.h" 36 37 /* Global pointer to shared data; NULL means no measured launch. */ 38 struct tboot *tboot __read_mostly; 39 EXPORT_SYMBOL(tboot); 40 41 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */ 42 #define AP_WAIT_TIMEOUT 1 43 44 #undef pr_fmt 45 #define pr_fmt(fmt) "tboot: " fmt 46 47 static u8 tboot_uuid[16] __initdata = TBOOT_UUID; 48 49 void __init tboot_probe(void) 50 { 51 /* Look for valid page-aligned address for shared page. */ 52 if (!boot_params.tboot_addr) 53 return; 54 /* 55 * also verify that it is mapped as we expect it before calling 56 * set_fixmap(), to reduce chance of garbage value causing crash 57 */ 58 if (!e820__mapped_any(boot_params.tboot_addr, 59 boot_params.tboot_addr, E820_TYPE_RESERVED)) { 60 pr_warning("non-0 tboot_addr but it is not of type E820_TYPE_RESERVED\n"); 61 return; 62 } 63 64 /* Map and check for tboot UUID. */ 65 set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr); 66 tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE); 67 if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) { 68 pr_warning("tboot at 0x%llx is invalid\n", 69 boot_params.tboot_addr); 70 tboot = NULL; 71 return; 72 } 73 if (tboot->version < 5) { 74 pr_warning("tboot version is invalid: %u\n", tboot->version); 75 tboot = NULL; 76 return; 77 } 78 79 pr_info("found shared page at phys addr 0x%llx:\n", 80 boot_params.tboot_addr); 81 pr_debug("version: %d\n", tboot->version); 82 pr_debug("log_addr: 0x%08x\n", tboot->log_addr); 83 pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry); 84 pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base); 85 pr_debug("tboot_size: 0x%x\n", tboot->tboot_size); 86 } 87 88 static pgd_t *tboot_pg_dir; 89 static struct mm_struct tboot_mm = { 90 .mm_rb = RB_ROOT, 91 .pgd = swapper_pg_dir, 92 .mm_users = ATOMIC_INIT(2), 93 .mm_count = ATOMIC_INIT(1), 94 .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem), 95 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), 96 .mmlist = LIST_HEAD_INIT(init_mm.mmlist), 97 }; 98 99 static inline void switch_to_tboot_pt(void) 100 { 101 write_cr3(virt_to_phys(tboot_pg_dir)); 102 } 103 104 static int map_tboot_page(unsigned long vaddr, unsigned long pfn, 105 pgprot_t prot) 106 { 107 pgd_t *pgd; 108 p4d_t *p4d; 109 pud_t *pud; 110 pmd_t *pmd; 111 pte_t *pte; 112 113 pgd = pgd_offset(&tboot_mm, vaddr); 114 p4d = p4d_alloc(&tboot_mm, pgd, vaddr); 115 if (!p4d) 116 return -1; 117 pud = pud_alloc(&tboot_mm, p4d, vaddr); 118 if (!pud) 119 return -1; 120 pmd = pmd_alloc(&tboot_mm, pud, vaddr); 121 if (!pmd) 122 return -1; 123 pte = pte_alloc_map(&tboot_mm, pmd, vaddr); 124 if (!pte) 125 return -1; 126 set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); 127 pte_unmap(pte); 128 129 /* 130 * PTI poisons low addresses in the kernel page tables in the 131 * name of making them unusable for userspace. To execute 132 * code at such a low address, the poison must be cleared. 133 * 134 * Note: 'pgd' actually gets set in p4d_alloc() _or_ 135 * pud_alloc() depending on 4/5-level paging. 136 */ 137 pgd->pgd &= ~_PAGE_NX; 138 139 return 0; 140 } 141 142 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, 143 unsigned long nr) 144 { 145 /* Reuse the original kernel mapping */ 146 tboot_pg_dir = pgd_alloc(&tboot_mm); 147 if (!tboot_pg_dir) 148 return -1; 149 150 for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { 151 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC)) 152 return -1; 153 } 154 155 return 0; 156 } 157 158 static void tboot_create_trampoline(void) 159 { 160 u32 map_base, map_size; 161 162 /* Create identity map for tboot shutdown code. */ 163 map_base = PFN_DOWN(tboot->tboot_base); 164 map_size = PFN_UP(tboot->tboot_size); 165 if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size)) 166 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", 167 map_base, map_size); 168 } 169 170 #ifdef CONFIG_ACPI_SLEEP 171 172 static void add_mac_region(phys_addr_t start, unsigned long size) 173 { 174 struct tboot_mac_region *mr; 175 phys_addr_t end = start + size; 176 177 if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS) 178 panic("tboot: Too many MAC regions\n"); 179 180 if (start && size) { 181 mr = &tboot->mac_regions[tboot->num_mac_regions++]; 182 mr->start = round_down(start, PAGE_SIZE); 183 mr->size = round_up(end, PAGE_SIZE) - mr->start; 184 } 185 } 186 187 static int tboot_setup_sleep(void) 188 { 189 int i; 190 191 tboot->num_mac_regions = 0; 192 193 for (i = 0; i < e820_table->nr_entries; i++) { 194 if ((e820_table->entries[i].type != E820_TYPE_RAM) 195 && (e820_table->entries[i].type != E820_TYPE_RESERVED_KERN)) 196 continue; 197 198 add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size); 199 } 200 201 tboot->acpi_sinfo.kernel_s3_resume_vector = 202 real_mode_header->wakeup_start; 203 204 return 0; 205 } 206 207 #else /* no CONFIG_ACPI_SLEEP */ 208 209 static int tboot_setup_sleep(void) 210 { 211 /* S3 shutdown requested, but S3 not supported by the kernel... */ 212 BUG(); 213 return -1; 214 } 215 216 #endif 217 218 void tboot_shutdown(u32 shutdown_type) 219 { 220 void (*shutdown)(void); 221 222 if (!tboot_enabled()) 223 return; 224 225 /* 226 * if we're being called before the 1:1 mapping is set up then just 227 * return and let the normal shutdown happen; this should only be 228 * due to very early panic() 229 */ 230 if (!tboot_pg_dir) 231 return; 232 233 /* if this is S3 then set regions to MAC */ 234 if (shutdown_type == TB_SHUTDOWN_S3) 235 if (tboot_setup_sleep()) 236 return; 237 238 tboot->shutdown_type = shutdown_type; 239 240 switch_to_tboot_pt(); 241 242 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; 243 shutdown(); 244 245 /* should not reach here */ 246 while (1) 247 halt(); 248 } 249 250 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) 251 { 252 #define TB_COPY_GAS(tbg, g) \ 253 tbg.space_id = g.space_id; \ 254 tbg.bit_width = g.bit_width; \ 255 tbg.bit_offset = g.bit_offset; \ 256 tbg.access_width = g.access_width; \ 257 tbg.address = g.address; 258 259 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); 260 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); 261 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); 262 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); 263 264 /* 265 * We need phys addr of waking vector, but can't use virt_to_phys() on 266 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys 267 * addr. 268 */ 269 tboot->acpi_sinfo.wakeup_vector = fadt->facs + 270 offsetof(struct acpi_table_facs, firmware_waking_vector); 271 } 272 273 static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) 274 { 275 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { 276 /* S0,1,2: */ -1, -1, -1, 277 /* S3: */ TB_SHUTDOWN_S3, 278 /* S4: */ TB_SHUTDOWN_S4, 279 /* S5: */ TB_SHUTDOWN_S5 }; 280 281 if (!tboot_enabled()) 282 return 0; 283 284 tboot_copy_fadt(&acpi_gbl_FADT); 285 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; 286 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; 287 /* we always use the 32b wakeup vector */ 288 tboot->acpi_sinfo.vector_width = 32; 289 290 if (sleep_state >= ACPI_S_STATE_COUNT || 291 acpi_shutdown_map[sleep_state] == -1) { 292 pr_warning("unsupported sleep state 0x%x\n", sleep_state); 293 return -1; 294 } 295 296 tboot_shutdown(acpi_shutdown_map[sleep_state]); 297 return 0; 298 } 299 300 static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b) 301 { 302 if (!tboot_enabled()) 303 return 0; 304 305 pr_warning("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)"); 306 return -ENODEV; 307 } 308 309 static atomic_t ap_wfs_count; 310 311 static int tboot_wait_for_aps(int num_aps) 312 { 313 unsigned long timeout; 314 315 timeout = AP_WAIT_TIMEOUT*HZ; 316 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps && 317 timeout) { 318 mdelay(1); 319 timeout--; 320 } 321 322 if (timeout) 323 pr_warning("tboot wait for APs timeout\n"); 324 325 return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps); 326 } 327 328 static int tboot_dying_cpu(unsigned int cpu) 329 { 330 atomic_inc(&ap_wfs_count); 331 if (num_online_cpus() == 1) { 332 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count))) 333 return -EBUSY; 334 } 335 return 0; 336 } 337 338 #ifdef CONFIG_DEBUG_FS 339 340 #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ 341 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } 342 343 #define TBOOT_SERIAL_LOG_ADDR 0x60000 344 #define TBOOT_SERIAL_LOG_SIZE 0x08000 345 #define LOG_MAX_SIZE_OFF 16 346 #define LOG_BUF_OFF 24 347 348 static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; 349 350 static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) 351 { 352 void __iomem *log_base; 353 u8 log_uuid[16]; 354 u32 max_size; 355 void *kbuf; 356 int ret = -EFAULT; 357 358 log_base = ioremap_nocache(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); 359 if (!log_base) 360 return ret; 361 362 memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); 363 if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid))) 364 goto err_iounmap; 365 366 max_size = readl(log_base + LOG_MAX_SIZE_OFF); 367 if (*ppos >= max_size) { 368 ret = 0; 369 goto err_iounmap; 370 } 371 372 if (*ppos + count > max_size) 373 count = max_size - *ppos; 374 375 kbuf = kmalloc(count, GFP_KERNEL); 376 if (!kbuf) { 377 ret = -ENOMEM; 378 goto err_iounmap; 379 } 380 381 memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); 382 if (copy_to_user(user_buf, kbuf, count)) 383 goto err_kfree; 384 385 *ppos += count; 386 387 ret = count; 388 389 err_kfree: 390 kfree(kbuf); 391 392 err_iounmap: 393 iounmap(log_base); 394 395 return ret; 396 } 397 398 static const struct file_operations tboot_log_fops = { 399 .read = tboot_log_read, 400 .llseek = default_llseek, 401 }; 402 403 #endif /* CONFIG_DEBUG_FS */ 404 405 static __init int tboot_late_init(void) 406 { 407 if (!tboot_enabled()) 408 return 0; 409 410 tboot_create_trampoline(); 411 412 atomic_set(&ap_wfs_count, 0); 413 cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL, 414 tboot_dying_cpu); 415 #ifdef CONFIG_DEBUG_FS 416 debugfs_create_file("tboot_log", S_IRUSR, 417 arch_debugfs_dir, NULL, &tboot_log_fops); 418 #endif 419 420 acpi_os_set_prepare_sleep(&tboot_sleep); 421 acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep); 422 return 0; 423 } 424 425 late_initcall(tboot_late_init); 426 427 /* 428 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) 429 */ 430 431 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 432 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 433 434 /* # pages for each config regs space - used by fixmap */ 435 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ 436 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) 437 438 /* offsets from pub/priv config space */ 439 #define TXTCR_HEAP_BASE 0x0300 440 #define TXTCR_HEAP_SIZE 0x0308 441 442 #define SHA1_SIZE 20 443 444 struct sha1_hash { 445 u8 hash[SHA1_SIZE]; 446 }; 447 448 struct sinit_mle_data { 449 u32 version; /* currently 6 */ 450 struct sha1_hash bios_acm_id; 451 u32 edx_senter_flags; 452 u64 mseg_valid; 453 struct sha1_hash sinit_hash; 454 struct sha1_hash mle_hash; 455 struct sha1_hash stm_hash; 456 struct sha1_hash lcp_policy_hash; 457 u32 lcp_policy_control; 458 u32 rlp_wakeup_addr; 459 u32 reserved; 460 u32 num_mdrs; 461 u32 mdrs_off; 462 u32 num_vtd_dmars; 463 u32 vtd_dmars_off; 464 } __packed; 465 466 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) 467 { 468 void *heap_base, *heap_ptr, *config; 469 470 if (!tboot_enabled()) 471 return dmar_tbl; 472 473 /* 474 * ACPI tables may not be DMA protected by tboot, so use DMAR copy 475 * SINIT saved in SinitMleData in TXT heap (which is DMA protected) 476 */ 477 478 /* map config space in order to get heap addr */ 479 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * 480 PAGE_SIZE); 481 if (!config) 482 return NULL; 483 484 /* now map TXT heap */ 485 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), 486 *(u64 *)(config + TXTCR_HEAP_SIZE)); 487 iounmap(config); 488 if (!heap_base) 489 return NULL; 490 491 /* walk heap to SinitMleData */ 492 /* skip BiosData */ 493 heap_ptr = heap_base + *(u64 *)heap_base; 494 /* skip OsMleData */ 495 heap_ptr += *(u64 *)heap_ptr; 496 /* skip OsSinitData */ 497 heap_ptr += *(u64 *)heap_ptr; 498 /* now points to SinitMleDataSize; set to SinitMleData */ 499 heap_ptr += sizeof(u64); 500 /* get addr of DMAR table */ 501 dmar_tbl = (struct acpi_table_header *)(heap_ptr + 502 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - 503 sizeof(u64)); 504 505 /* don't unmap heap because dmar.c needs access to this */ 506 507 return dmar_tbl; 508 } 509 510 int tboot_force_iommu(void) 511 { 512 if (!tboot_enabled()) 513 return 0; 514 515 if (intel_iommu_tboot_noforce) 516 return 1; 517 518 if (no_iommu || swiotlb || dmar_disabled) 519 pr_warning("Forcing Intel-IOMMU to enabled\n"); 520 521 dmar_disabled = 0; 522 #ifdef CONFIG_SWIOTLB 523 swiotlb = 0; 524 #endif 525 no_iommu = 0; 526 527 return 1; 528 } 529