1 /* 2 * tboot.c: main implementation of helper functions used by kernel for 3 * runtime support of Intel(R) Trusted Execution Technology 4 * 5 * Copyright (c) 2006-2009, Intel Corporation 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms and conditions of the GNU General Public License, 9 * version 2, as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License along with 17 * this program; if not, write to the Free Software Foundation, Inc., 18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 */ 21 22 #include <linux/intel-iommu.h> 23 #include <linux/init_task.h> 24 #include <linux/spinlock.h> 25 #include <linux/export.h> 26 #include <linux/delay.h> 27 #include <linux/sched.h> 28 #include <linux/init.h> 29 #include <linux/dmar.h> 30 #include <linux/cpu.h> 31 #include <linux/pfn.h> 32 #include <linux/mm.h> 33 #include <linux/tboot.h> 34 #include <linux/debugfs.h> 35 36 #include <asm/realmode.h> 37 #include <asm/processor.h> 38 #include <asm/bootparam.h> 39 #include <asm/pgtable.h> 40 #include <asm/pgalloc.h> 41 #include <asm/swiotlb.h> 42 #include <asm/fixmap.h> 43 #include <asm/proto.h> 44 #include <asm/setup.h> 45 #include <asm/e820/api.h> 46 #include <asm/io.h> 47 48 #include "../realmode/rm/wakeup.h" 49 50 /* Global pointer to shared data; NULL means no measured launch. */ 51 struct tboot *tboot __read_mostly; 52 EXPORT_SYMBOL(tboot); 53 54 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */ 55 #define AP_WAIT_TIMEOUT 1 56 57 #undef pr_fmt 58 #define pr_fmt(fmt) "tboot: " fmt 59 60 static u8 tboot_uuid[16] __initdata = TBOOT_UUID; 61 62 void __init tboot_probe(void) 63 { 64 /* Look for valid page-aligned address for shared page. */ 65 if (!boot_params.tboot_addr) 66 return; 67 /* 68 * also verify that it is mapped as we expect it before calling 69 * set_fixmap(), to reduce chance of garbage value causing crash 70 */ 71 if (!e820__mapped_any(boot_params.tboot_addr, 72 boot_params.tboot_addr, E820_TYPE_RESERVED)) { 73 pr_warning("non-0 tboot_addr but it is not of type E820_TYPE_RESERVED\n"); 74 return; 75 } 76 77 /* Map and check for tboot UUID. */ 78 set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr); 79 tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE); 80 if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) { 81 pr_warning("tboot at 0x%llx is invalid\n", 82 boot_params.tboot_addr); 83 tboot = NULL; 84 return; 85 } 86 if (tboot->version < 5) { 87 pr_warning("tboot version is invalid: %u\n", tboot->version); 88 tboot = NULL; 89 return; 90 } 91 92 pr_info("found shared page at phys addr 0x%llx:\n", 93 boot_params.tboot_addr); 94 pr_debug("version: %d\n", tboot->version); 95 pr_debug("log_addr: 0x%08x\n", tboot->log_addr); 96 pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry); 97 pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base); 98 pr_debug("tboot_size: 0x%x\n", tboot->tboot_size); 99 } 100 101 static pgd_t *tboot_pg_dir; 102 static struct mm_struct tboot_mm = { 103 .mm_rb = RB_ROOT, 104 .pgd = swapper_pg_dir, 105 .mm_users = ATOMIC_INIT(2), 106 .mm_count = ATOMIC_INIT(1), 107 .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem), 108 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), 109 .mmlist = LIST_HEAD_INIT(init_mm.mmlist), 110 }; 111 112 static inline void switch_to_tboot_pt(void) 113 { 114 write_cr3(virt_to_phys(tboot_pg_dir)); 115 } 116 117 static int map_tboot_page(unsigned long vaddr, unsigned long pfn, 118 pgprot_t prot) 119 { 120 pgd_t *pgd; 121 p4d_t *p4d; 122 pud_t *pud; 123 pmd_t *pmd; 124 pte_t *pte; 125 126 pgd = pgd_offset(&tboot_mm, vaddr); 127 p4d = p4d_alloc(&tboot_mm, pgd, vaddr); 128 if (!p4d) 129 return -1; 130 pud = pud_alloc(&tboot_mm, p4d, vaddr); 131 if (!pud) 132 return -1; 133 pmd = pmd_alloc(&tboot_mm, pud, vaddr); 134 if (!pmd) 135 return -1; 136 pte = pte_alloc_map(&tboot_mm, pmd, vaddr); 137 if (!pte) 138 return -1; 139 set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); 140 pte_unmap(pte); 141 142 /* 143 * PTI poisons low addresses in the kernel page tables in the 144 * name of making them unusable for userspace. To execute 145 * code at such a low address, the poison must be cleared. 146 * 147 * Note: 'pgd' actually gets set in p4d_alloc() _or_ 148 * pud_alloc() depending on 4/5-level paging. 149 */ 150 pgd->pgd &= ~_PAGE_NX; 151 152 return 0; 153 } 154 155 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, 156 unsigned long nr) 157 { 158 /* Reuse the original kernel mapping */ 159 tboot_pg_dir = pgd_alloc(&tboot_mm); 160 if (!tboot_pg_dir) 161 return -1; 162 163 for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { 164 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC)) 165 return -1; 166 } 167 168 return 0; 169 } 170 171 static void tboot_create_trampoline(void) 172 { 173 u32 map_base, map_size; 174 175 /* Create identity map for tboot shutdown code. */ 176 map_base = PFN_DOWN(tboot->tboot_base); 177 map_size = PFN_UP(tboot->tboot_size); 178 if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size)) 179 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", 180 map_base, map_size); 181 } 182 183 #ifdef CONFIG_ACPI_SLEEP 184 185 static void add_mac_region(phys_addr_t start, unsigned long size) 186 { 187 struct tboot_mac_region *mr; 188 phys_addr_t end = start + size; 189 190 if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS) 191 panic("tboot: Too many MAC regions\n"); 192 193 if (start && size) { 194 mr = &tboot->mac_regions[tboot->num_mac_regions++]; 195 mr->start = round_down(start, PAGE_SIZE); 196 mr->size = round_up(end, PAGE_SIZE) - mr->start; 197 } 198 } 199 200 static int tboot_setup_sleep(void) 201 { 202 int i; 203 204 tboot->num_mac_regions = 0; 205 206 for (i = 0; i < e820_table->nr_entries; i++) { 207 if ((e820_table->entries[i].type != E820_TYPE_RAM) 208 && (e820_table->entries[i].type != E820_TYPE_RESERVED_KERN)) 209 continue; 210 211 add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size); 212 } 213 214 tboot->acpi_sinfo.kernel_s3_resume_vector = 215 real_mode_header->wakeup_start; 216 217 return 0; 218 } 219 220 #else /* no CONFIG_ACPI_SLEEP */ 221 222 static int tboot_setup_sleep(void) 223 { 224 /* S3 shutdown requested, but S3 not supported by the kernel... */ 225 BUG(); 226 return -1; 227 } 228 229 #endif 230 231 void tboot_shutdown(u32 shutdown_type) 232 { 233 void (*shutdown)(void); 234 235 if (!tboot_enabled()) 236 return; 237 238 /* 239 * if we're being called before the 1:1 mapping is set up then just 240 * return and let the normal shutdown happen; this should only be 241 * due to very early panic() 242 */ 243 if (!tboot_pg_dir) 244 return; 245 246 /* if this is S3 then set regions to MAC */ 247 if (shutdown_type == TB_SHUTDOWN_S3) 248 if (tboot_setup_sleep()) 249 return; 250 251 tboot->shutdown_type = shutdown_type; 252 253 switch_to_tboot_pt(); 254 255 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; 256 shutdown(); 257 258 /* should not reach here */ 259 while (1) 260 halt(); 261 } 262 263 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) 264 { 265 #define TB_COPY_GAS(tbg, g) \ 266 tbg.space_id = g.space_id; \ 267 tbg.bit_width = g.bit_width; \ 268 tbg.bit_offset = g.bit_offset; \ 269 tbg.access_width = g.access_width; \ 270 tbg.address = g.address; 271 272 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); 273 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); 274 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); 275 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); 276 277 /* 278 * We need phys addr of waking vector, but can't use virt_to_phys() on 279 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys 280 * addr. 281 */ 282 tboot->acpi_sinfo.wakeup_vector = fadt->facs + 283 offsetof(struct acpi_table_facs, firmware_waking_vector); 284 } 285 286 static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) 287 { 288 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { 289 /* S0,1,2: */ -1, -1, -1, 290 /* S3: */ TB_SHUTDOWN_S3, 291 /* S4: */ TB_SHUTDOWN_S4, 292 /* S5: */ TB_SHUTDOWN_S5 }; 293 294 if (!tboot_enabled()) 295 return 0; 296 297 tboot_copy_fadt(&acpi_gbl_FADT); 298 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; 299 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; 300 /* we always use the 32b wakeup vector */ 301 tboot->acpi_sinfo.vector_width = 32; 302 303 if (sleep_state >= ACPI_S_STATE_COUNT || 304 acpi_shutdown_map[sleep_state] == -1) { 305 pr_warning("unsupported sleep state 0x%x\n", sleep_state); 306 return -1; 307 } 308 309 tboot_shutdown(acpi_shutdown_map[sleep_state]); 310 return 0; 311 } 312 313 static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b) 314 { 315 if (!tboot_enabled()) 316 return 0; 317 318 pr_warning("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)"); 319 return -ENODEV; 320 } 321 322 static atomic_t ap_wfs_count; 323 324 static int tboot_wait_for_aps(int num_aps) 325 { 326 unsigned long timeout; 327 328 timeout = AP_WAIT_TIMEOUT*HZ; 329 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps && 330 timeout) { 331 mdelay(1); 332 timeout--; 333 } 334 335 if (timeout) 336 pr_warning("tboot wait for APs timeout\n"); 337 338 return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps); 339 } 340 341 static int tboot_dying_cpu(unsigned int cpu) 342 { 343 atomic_inc(&ap_wfs_count); 344 if (num_online_cpus() == 1) { 345 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count))) 346 return -EBUSY; 347 } 348 return 0; 349 } 350 351 #ifdef CONFIG_DEBUG_FS 352 353 #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ 354 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } 355 356 #define TBOOT_SERIAL_LOG_ADDR 0x60000 357 #define TBOOT_SERIAL_LOG_SIZE 0x08000 358 #define LOG_MAX_SIZE_OFF 16 359 #define LOG_BUF_OFF 24 360 361 static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; 362 363 static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) 364 { 365 void __iomem *log_base; 366 u8 log_uuid[16]; 367 u32 max_size; 368 void *kbuf; 369 int ret = -EFAULT; 370 371 log_base = ioremap_nocache(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); 372 if (!log_base) 373 return ret; 374 375 memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); 376 if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid))) 377 goto err_iounmap; 378 379 max_size = readl(log_base + LOG_MAX_SIZE_OFF); 380 if (*ppos >= max_size) { 381 ret = 0; 382 goto err_iounmap; 383 } 384 385 if (*ppos + count > max_size) 386 count = max_size - *ppos; 387 388 kbuf = kmalloc(count, GFP_KERNEL); 389 if (!kbuf) { 390 ret = -ENOMEM; 391 goto err_iounmap; 392 } 393 394 memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); 395 if (copy_to_user(user_buf, kbuf, count)) 396 goto err_kfree; 397 398 *ppos += count; 399 400 ret = count; 401 402 err_kfree: 403 kfree(kbuf); 404 405 err_iounmap: 406 iounmap(log_base); 407 408 return ret; 409 } 410 411 static const struct file_operations tboot_log_fops = { 412 .read = tboot_log_read, 413 .llseek = default_llseek, 414 }; 415 416 #endif /* CONFIG_DEBUG_FS */ 417 418 static __init int tboot_late_init(void) 419 { 420 if (!tboot_enabled()) 421 return 0; 422 423 tboot_create_trampoline(); 424 425 atomic_set(&ap_wfs_count, 0); 426 cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL, 427 tboot_dying_cpu); 428 #ifdef CONFIG_DEBUG_FS 429 debugfs_create_file("tboot_log", S_IRUSR, 430 arch_debugfs_dir, NULL, &tboot_log_fops); 431 #endif 432 433 acpi_os_set_prepare_sleep(&tboot_sleep); 434 acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep); 435 return 0; 436 } 437 438 late_initcall(tboot_late_init); 439 440 /* 441 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) 442 */ 443 444 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 445 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 446 447 /* # pages for each config regs space - used by fixmap */ 448 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ 449 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) 450 451 /* offsets from pub/priv config space */ 452 #define TXTCR_HEAP_BASE 0x0300 453 #define TXTCR_HEAP_SIZE 0x0308 454 455 #define SHA1_SIZE 20 456 457 struct sha1_hash { 458 u8 hash[SHA1_SIZE]; 459 }; 460 461 struct sinit_mle_data { 462 u32 version; /* currently 6 */ 463 struct sha1_hash bios_acm_id; 464 u32 edx_senter_flags; 465 u64 mseg_valid; 466 struct sha1_hash sinit_hash; 467 struct sha1_hash mle_hash; 468 struct sha1_hash stm_hash; 469 struct sha1_hash lcp_policy_hash; 470 u32 lcp_policy_control; 471 u32 rlp_wakeup_addr; 472 u32 reserved; 473 u32 num_mdrs; 474 u32 mdrs_off; 475 u32 num_vtd_dmars; 476 u32 vtd_dmars_off; 477 } __packed; 478 479 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) 480 { 481 void *heap_base, *heap_ptr, *config; 482 483 if (!tboot_enabled()) 484 return dmar_tbl; 485 486 /* 487 * ACPI tables may not be DMA protected by tboot, so use DMAR copy 488 * SINIT saved in SinitMleData in TXT heap (which is DMA protected) 489 */ 490 491 /* map config space in order to get heap addr */ 492 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * 493 PAGE_SIZE); 494 if (!config) 495 return NULL; 496 497 /* now map TXT heap */ 498 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), 499 *(u64 *)(config + TXTCR_HEAP_SIZE)); 500 iounmap(config); 501 if (!heap_base) 502 return NULL; 503 504 /* walk heap to SinitMleData */ 505 /* skip BiosData */ 506 heap_ptr = heap_base + *(u64 *)heap_base; 507 /* skip OsMleData */ 508 heap_ptr += *(u64 *)heap_ptr; 509 /* skip OsSinitData */ 510 heap_ptr += *(u64 *)heap_ptr; 511 /* now points to SinitMleDataSize; set to SinitMleData */ 512 heap_ptr += sizeof(u64); 513 /* get addr of DMAR table */ 514 dmar_tbl = (struct acpi_table_header *)(heap_ptr + 515 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - 516 sizeof(u64)); 517 518 /* don't unmap heap because dmar.c needs access to this */ 519 520 return dmar_tbl; 521 } 522 523 int tboot_force_iommu(void) 524 { 525 if (!tboot_enabled()) 526 return 0; 527 528 if (intel_iommu_tboot_noforce) 529 return 1; 530 531 if (no_iommu || swiotlb || dmar_disabled) 532 pr_warning("Forcing Intel-IOMMU to enabled\n"); 533 534 dmar_disabled = 0; 535 #ifdef CONFIG_SWIOTLB 536 swiotlb = 0; 537 #endif 538 no_iommu = 0; 539 540 return 1; 541 } 542