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/dma_remapping.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_RESERVED)) { 73 pr_warning("non-0 tboot_addr but it is not of type E820_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 pud_t *pud; 122 pmd_t *pmd; 123 pte_t *pte; 124 125 pgd = pgd_offset(&tboot_mm, vaddr); 126 pud = pud_alloc(&tboot_mm, pgd, 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 return 0; 138 } 139 140 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, 141 unsigned long nr) 142 { 143 /* Reuse the original kernel mapping */ 144 tboot_pg_dir = pgd_alloc(&tboot_mm); 145 if (!tboot_pg_dir) 146 return -1; 147 148 for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { 149 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC)) 150 return -1; 151 } 152 153 return 0; 154 } 155 156 static void tboot_create_trampoline(void) 157 { 158 u32 map_base, map_size; 159 160 /* Create identity map for tboot shutdown code. */ 161 map_base = PFN_DOWN(tboot->tboot_base); 162 map_size = PFN_UP(tboot->tboot_size); 163 if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size)) 164 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", 165 map_base, map_size); 166 } 167 168 #ifdef CONFIG_ACPI_SLEEP 169 170 static void add_mac_region(phys_addr_t start, unsigned long size) 171 { 172 struct tboot_mac_region *mr; 173 phys_addr_t end = start + size; 174 175 if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS) 176 panic("tboot: Too many MAC regions\n"); 177 178 if (start && size) { 179 mr = &tboot->mac_regions[tboot->num_mac_regions++]; 180 mr->start = round_down(start, PAGE_SIZE); 181 mr->size = round_up(end, PAGE_SIZE) - mr->start; 182 } 183 } 184 185 static int tboot_setup_sleep(void) 186 { 187 int i; 188 189 tboot->num_mac_regions = 0; 190 191 for (i = 0; i < e820_table->nr_entries; i++) { 192 if ((e820_table->entries[i].type != E820_RAM) 193 && (e820_table->entries[i].type != E820_RESERVED_KERN)) 194 continue; 195 196 add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size); 197 } 198 199 tboot->acpi_sinfo.kernel_s3_resume_vector = 200 real_mode_header->wakeup_start; 201 202 return 0; 203 } 204 205 #else /* no CONFIG_ACPI_SLEEP */ 206 207 static int tboot_setup_sleep(void) 208 { 209 /* S3 shutdown requested, but S3 not supported by the kernel... */ 210 BUG(); 211 return -1; 212 } 213 214 #endif 215 216 void tboot_shutdown(u32 shutdown_type) 217 { 218 void (*shutdown)(void); 219 220 if (!tboot_enabled()) 221 return; 222 223 /* 224 * if we're being called before the 1:1 mapping is set up then just 225 * return and let the normal shutdown happen; this should only be 226 * due to very early panic() 227 */ 228 if (!tboot_pg_dir) 229 return; 230 231 /* if this is S3 then set regions to MAC */ 232 if (shutdown_type == TB_SHUTDOWN_S3) 233 if (tboot_setup_sleep()) 234 return; 235 236 tboot->shutdown_type = shutdown_type; 237 238 switch_to_tboot_pt(); 239 240 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; 241 shutdown(); 242 243 /* should not reach here */ 244 while (1) 245 halt(); 246 } 247 248 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) 249 { 250 #define TB_COPY_GAS(tbg, g) \ 251 tbg.space_id = g.space_id; \ 252 tbg.bit_width = g.bit_width; \ 253 tbg.bit_offset = g.bit_offset; \ 254 tbg.access_width = g.access_width; \ 255 tbg.address = g.address; 256 257 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); 258 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); 259 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); 260 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); 261 262 /* 263 * We need phys addr of waking vector, but can't use virt_to_phys() on 264 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys 265 * addr. 266 */ 267 tboot->acpi_sinfo.wakeup_vector = fadt->facs + 268 offsetof(struct acpi_table_facs, firmware_waking_vector); 269 } 270 271 static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) 272 { 273 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { 274 /* S0,1,2: */ -1, -1, -1, 275 /* S3: */ TB_SHUTDOWN_S3, 276 /* S4: */ TB_SHUTDOWN_S4, 277 /* S5: */ TB_SHUTDOWN_S5 }; 278 279 if (!tboot_enabled()) 280 return 0; 281 282 tboot_copy_fadt(&acpi_gbl_FADT); 283 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; 284 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; 285 /* we always use the 32b wakeup vector */ 286 tboot->acpi_sinfo.vector_width = 32; 287 288 if (sleep_state >= ACPI_S_STATE_COUNT || 289 acpi_shutdown_map[sleep_state] == -1) { 290 pr_warning("unsupported sleep state 0x%x\n", sleep_state); 291 return -1; 292 } 293 294 tboot_shutdown(acpi_shutdown_map[sleep_state]); 295 return 0; 296 } 297 298 static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b) 299 { 300 if (!tboot_enabled()) 301 return 0; 302 303 pr_warning("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)"); 304 return -ENODEV; 305 } 306 307 static atomic_t ap_wfs_count; 308 309 static int tboot_wait_for_aps(int num_aps) 310 { 311 unsigned long timeout; 312 313 timeout = AP_WAIT_TIMEOUT*HZ; 314 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps && 315 timeout) { 316 mdelay(1); 317 timeout--; 318 } 319 320 if (timeout) 321 pr_warning("tboot wait for APs timeout\n"); 322 323 return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps); 324 } 325 326 static int tboot_dying_cpu(unsigned int cpu) 327 { 328 atomic_inc(&ap_wfs_count); 329 if (num_online_cpus() == 1) { 330 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count))) 331 return -EBUSY; 332 } 333 return 0; 334 } 335 336 #ifdef CONFIG_DEBUG_FS 337 338 #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ 339 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } 340 341 #define TBOOT_SERIAL_LOG_ADDR 0x60000 342 #define TBOOT_SERIAL_LOG_SIZE 0x08000 343 #define LOG_MAX_SIZE_OFF 16 344 #define LOG_BUF_OFF 24 345 346 static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; 347 348 static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) 349 { 350 void __iomem *log_base; 351 u8 log_uuid[16]; 352 u32 max_size; 353 void *kbuf; 354 int ret = -EFAULT; 355 356 log_base = ioremap_nocache(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); 357 if (!log_base) 358 return ret; 359 360 memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); 361 if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid))) 362 goto err_iounmap; 363 364 max_size = readl(log_base + LOG_MAX_SIZE_OFF); 365 if (*ppos >= max_size) { 366 ret = 0; 367 goto err_iounmap; 368 } 369 370 if (*ppos + count > max_size) 371 count = max_size - *ppos; 372 373 kbuf = kmalloc(count, GFP_KERNEL); 374 if (!kbuf) { 375 ret = -ENOMEM; 376 goto err_iounmap; 377 } 378 379 memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); 380 if (copy_to_user(user_buf, kbuf, count)) 381 goto err_kfree; 382 383 *ppos += count; 384 385 ret = count; 386 387 err_kfree: 388 kfree(kbuf); 389 390 err_iounmap: 391 iounmap(log_base); 392 393 return ret; 394 } 395 396 static const struct file_operations tboot_log_fops = { 397 .read = tboot_log_read, 398 .llseek = default_llseek, 399 }; 400 401 #endif /* CONFIG_DEBUG_FS */ 402 403 static __init int tboot_late_init(void) 404 { 405 if (!tboot_enabled()) 406 return 0; 407 408 tboot_create_trampoline(); 409 410 atomic_set(&ap_wfs_count, 0); 411 cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL, 412 tboot_dying_cpu); 413 #ifdef CONFIG_DEBUG_FS 414 debugfs_create_file("tboot_log", S_IRUSR, 415 arch_debugfs_dir, NULL, &tboot_log_fops); 416 #endif 417 418 acpi_os_set_prepare_sleep(&tboot_sleep); 419 acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep); 420 return 0; 421 } 422 423 late_initcall(tboot_late_init); 424 425 /* 426 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) 427 */ 428 429 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 430 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 431 432 /* # pages for each config regs space - used by fixmap */ 433 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ 434 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) 435 436 /* offsets from pub/priv config space */ 437 #define TXTCR_HEAP_BASE 0x0300 438 #define TXTCR_HEAP_SIZE 0x0308 439 440 #define SHA1_SIZE 20 441 442 struct sha1_hash { 443 u8 hash[SHA1_SIZE]; 444 }; 445 446 struct sinit_mle_data { 447 u32 version; /* currently 6 */ 448 struct sha1_hash bios_acm_id; 449 u32 edx_senter_flags; 450 u64 mseg_valid; 451 struct sha1_hash sinit_hash; 452 struct sha1_hash mle_hash; 453 struct sha1_hash stm_hash; 454 struct sha1_hash lcp_policy_hash; 455 u32 lcp_policy_control; 456 u32 rlp_wakeup_addr; 457 u32 reserved; 458 u32 num_mdrs; 459 u32 mdrs_off; 460 u32 num_vtd_dmars; 461 u32 vtd_dmars_off; 462 } __packed; 463 464 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) 465 { 466 void *heap_base, *heap_ptr, *config; 467 468 if (!tboot_enabled()) 469 return dmar_tbl; 470 471 /* 472 * ACPI tables may not be DMA protected by tboot, so use DMAR copy 473 * SINIT saved in SinitMleData in TXT heap (which is DMA protected) 474 */ 475 476 /* map config space in order to get heap addr */ 477 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * 478 PAGE_SIZE); 479 if (!config) 480 return NULL; 481 482 /* now map TXT heap */ 483 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), 484 *(u64 *)(config + TXTCR_HEAP_SIZE)); 485 iounmap(config); 486 if (!heap_base) 487 return NULL; 488 489 /* walk heap to SinitMleData */ 490 /* skip BiosData */ 491 heap_ptr = heap_base + *(u64 *)heap_base; 492 /* skip OsMleData */ 493 heap_ptr += *(u64 *)heap_ptr; 494 /* skip OsSinitData */ 495 heap_ptr += *(u64 *)heap_ptr; 496 /* now points to SinitMleDataSize; set to SinitMleData */ 497 heap_ptr += sizeof(u64); 498 /* get addr of DMAR table */ 499 dmar_tbl = (struct acpi_table_header *)(heap_ptr + 500 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - 501 sizeof(u64)); 502 503 /* don't unmap heap because dmar.c needs access to this */ 504 505 return dmar_tbl; 506 } 507 508 int tboot_force_iommu(void) 509 { 510 if (!tboot_enabled()) 511 return 0; 512 513 if (no_iommu || swiotlb || dmar_disabled) 514 pr_warning("Forcing Intel-IOMMU to enabled\n"); 515 516 dmar_disabled = 0; 517 #ifdef CONFIG_SWIOTLB 518 swiotlb = 0; 519 #endif 520 no_iommu = 0; 521 522 return 1; 523 } 524