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.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_any_mapped(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 /* only a natively booted kernel should be using TXT */ 78 if (paravirt_enabled()) { 79 pr_warning("non-0 tboot_addr but pv_ops is enabled\n"); 80 return; 81 } 82 83 /* Map and check for tboot UUID. */ 84 set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr); 85 tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE); 86 if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) { 87 pr_warning("tboot at 0x%llx is invalid\n", 88 boot_params.tboot_addr); 89 tboot = NULL; 90 return; 91 } 92 if (tboot->version < 5) { 93 pr_warning("tboot version is invalid: %u\n", tboot->version); 94 tboot = NULL; 95 return; 96 } 97 98 pr_info("found shared page at phys addr 0x%llx:\n", 99 boot_params.tboot_addr); 100 pr_debug("version: %d\n", tboot->version); 101 pr_debug("log_addr: 0x%08x\n", tboot->log_addr); 102 pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry); 103 pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base); 104 pr_debug("tboot_size: 0x%x\n", tboot->tboot_size); 105 } 106 107 static pgd_t *tboot_pg_dir; 108 static struct mm_struct tboot_mm = { 109 .mm_rb = RB_ROOT, 110 .pgd = swapper_pg_dir, 111 .mm_users = ATOMIC_INIT(2), 112 .mm_count = ATOMIC_INIT(1), 113 .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem), 114 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), 115 .mmlist = LIST_HEAD_INIT(init_mm.mmlist), 116 }; 117 118 static inline void switch_to_tboot_pt(void) 119 { 120 write_cr3(virt_to_phys(tboot_pg_dir)); 121 } 122 123 static int map_tboot_page(unsigned long vaddr, unsigned long pfn, 124 pgprot_t prot) 125 { 126 pgd_t *pgd; 127 pud_t *pud; 128 pmd_t *pmd; 129 pte_t *pte; 130 131 pgd = pgd_offset(&tboot_mm, vaddr); 132 pud = pud_alloc(&tboot_mm, pgd, vaddr); 133 if (!pud) 134 return -1; 135 pmd = pmd_alloc(&tboot_mm, pud, vaddr); 136 if (!pmd) 137 return -1; 138 pte = pte_alloc_map(&tboot_mm, NULL, pmd, vaddr); 139 if (!pte) 140 return -1; 141 set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); 142 pte_unmap(pte); 143 return 0; 144 } 145 146 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, 147 unsigned long nr) 148 { 149 /* Reuse the original kernel mapping */ 150 tboot_pg_dir = pgd_alloc(&tboot_mm); 151 if (!tboot_pg_dir) 152 return -1; 153 154 for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { 155 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC)) 156 return -1; 157 } 158 159 return 0; 160 } 161 162 static void tboot_create_trampoline(void) 163 { 164 u32 map_base, map_size; 165 166 /* Create identity map for tboot shutdown code. */ 167 map_base = PFN_DOWN(tboot->tboot_base); 168 map_size = PFN_UP(tboot->tboot_size); 169 if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size)) 170 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", 171 map_base, map_size); 172 } 173 174 #ifdef CONFIG_ACPI_SLEEP 175 176 static void add_mac_region(phys_addr_t start, unsigned long size) 177 { 178 struct tboot_mac_region *mr; 179 phys_addr_t end = start + size; 180 181 if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS) 182 panic("tboot: Too many MAC regions\n"); 183 184 if (start && size) { 185 mr = &tboot->mac_regions[tboot->num_mac_regions++]; 186 mr->start = round_down(start, PAGE_SIZE); 187 mr->size = round_up(end, PAGE_SIZE) - mr->start; 188 } 189 } 190 191 static int tboot_setup_sleep(void) 192 { 193 int i; 194 195 tboot->num_mac_regions = 0; 196 197 for (i = 0; i < e820.nr_map; i++) { 198 if ((e820.map[i].type != E820_RAM) 199 && (e820.map[i].type != E820_RESERVED_KERN)) 200 continue; 201 202 add_mac_region(e820.map[i].addr, e820.map[i].size); 203 } 204 205 tboot->acpi_sinfo.kernel_s3_resume_vector = 206 real_mode_header->wakeup_start; 207 208 return 0; 209 } 210 211 #else /* no CONFIG_ACPI_SLEEP */ 212 213 static int tboot_setup_sleep(void) 214 { 215 /* S3 shutdown requested, but S3 not supported by the kernel... */ 216 BUG(); 217 return -1; 218 } 219 220 #endif 221 222 void tboot_shutdown(u32 shutdown_type) 223 { 224 void (*shutdown)(void); 225 226 if (!tboot_enabled()) 227 return; 228 229 /* 230 * if we're being called before the 1:1 mapping is set up then just 231 * return and let the normal shutdown happen; this should only be 232 * due to very early panic() 233 */ 234 if (!tboot_pg_dir) 235 return; 236 237 /* if this is S3 then set regions to MAC */ 238 if (shutdown_type == TB_SHUTDOWN_S3) 239 if (tboot_setup_sleep()) 240 return; 241 242 tboot->shutdown_type = shutdown_type; 243 244 switch_to_tboot_pt(); 245 246 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; 247 shutdown(); 248 249 /* should not reach here */ 250 while (1) 251 halt(); 252 } 253 254 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) 255 { 256 #define TB_COPY_GAS(tbg, g) \ 257 tbg.space_id = g.space_id; \ 258 tbg.bit_width = g.bit_width; \ 259 tbg.bit_offset = g.bit_offset; \ 260 tbg.access_width = g.access_width; \ 261 tbg.address = g.address; 262 263 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); 264 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); 265 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); 266 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); 267 268 /* 269 * We need phys addr of waking vector, but can't use virt_to_phys() on 270 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys 271 * addr. 272 */ 273 tboot->acpi_sinfo.wakeup_vector = fadt->facs + 274 offsetof(struct acpi_table_facs, firmware_waking_vector); 275 } 276 277 static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) 278 { 279 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { 280 /* S0,1,2: */ -1, -1, -1, 281 /* S3: */ TB_SHUTDOWN_S3, 282 /* S4: */ TB_SHUTDOWN_S4, 283 /* S5: */ TB_SHUTDOWN_S5 }; 284 285 if (!tboot_enabled()) 286 return 0; 287 288 tboot_copy_fadt(&acpi_gbl_FADT); 289 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; 290 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; 291 /* we always use the 32b wakeup vector */ 292 tboot->acpi_sinfo.vector_width = 32; 293 294 if (sleep_state >= ACPI_S_STATE_COUNT || 295 acpi_shutdown_map[sleep_state] == -1) { 296 pr_warning("unsupported sleep state 0x%x\n", sleep_state); 297 return -1; 298 } 299 300 tboot_shutdown(acpi_shutdown_map[sleep_state]); 301 return 0; 302 } 303 304 static atomic_t ap_wfs_count; 305 306 static int tboot_wait_for_aps(int num_aps) 307 { 308 unsigned long timeout; 309 310 timeout = AP_WAIT_TIMEOUT*HZ; 311 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps && 312 timeout) { 313 mdelay(1); 314 timeout--; 315 } 316 317 if (timeout) 318 pr_warning("tboot wait for APs timeout\n"); 319 320 return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps); 321 } 322 323 static int tboot_cpu_callback(struct notifier_block *nfb, unsigned long action, 324 void *hcpu) 325 { 326 switch (action) { 327 case CPU_DYING: 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 NOTIFY_BAD; 332 break; 333 } 334 return NOTIFY_OK; 335 } 336 337 static struct notifier_block tboot_cpu_notifier = 338 { 339 .notifier_call = tboot_cpu_callback, 340 }; 341 342 #ifdef CONFIG_DEBUG_FS 343 344 #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ 345 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } 346 347 #define TBOOT_SERIAL_LOG_ADDR 0x60000 348 #define TBOOT_SERIAL_LOG_SIZE 0x08000 349 #define LOG_MAX_SIZE_OFF 16 350 #define LOG_BUF_OFF 24 351 352 static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; 353 354 static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) 355 { 356 void __iomem *log_base; 357 u8 log_uuid[16]; 358 u32 max_size; 359 void *kbuf; 360 int ret = -EFAULT; 361 362 log_base = ioremap_nocache(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); 363 if (!log_base) 364 return ret; 365 366 memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); 367 if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid))) 368 goto err_iounmap; 369 370 max_size = readl(log_base + LOG_MAX_SIZE_OFF); 371 if (*ppos >= max_size) { 372 ret = 0; 373 goto err_iounmap; 374 } 375 376 if (*ppos + count > max_size) 377 count = max_size - *ppos; 378 379 kbuf = kmalloc(count, GFP_KERNEL); 380 if (!kbuf) { 381 ret = -ENOMEM; 382 goto err_iounmap; 383 } 384 385 memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); 386 if (copy_to_user(user_buf, kbuf, count)) 387 goto err_kfree; 388 389 *ppos += count; 390 391 ret = count; 392 393 err_kfree: 394 kfree(kbuf); 395 396 err_iounmap: 397 iounmap(log_base); 398 399 return ret; 400 } 401 402 static const struct file_operations tboot_log_fops = { 403 .read = tboot_log_read, 404 .llseek = default_llseek, 405 }; 406 407 #endif /* CONFIG_DEBUG_FS */ 408 409 static __init int tboot_late_init(void) 410 { 411 if (!tboot_enabled()) 412 return 0; 413 414 tboot_create_trampoline(); 415 416 atomic_set(&ap_wfs_count, 0); 417 register_hotcpu_notifier(&tboot_cpu_notifier); 418 419 #ifdef CONFIG_DEBUG_FS 420 debugfs_create_file("tboot_log", S_IRUSR, 421 arch_debugfs_dir, NULL, &tboot_log_fops); 422 #endif 423 424 acpi_os_set_prepare_sleep(&tboot_sleep); 425 return 0; 426 } 427 428 late_initcall(tboot_late_init); 429 430 /* 431 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) 432 */ 433 434 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 435 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 436 437 /* # pages for each config regs space - used by fixmap */ 438 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ 439 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) 440 441 /* offsets from pub/priv config space */ 442 #define TXTCR_HEAP_BASE 0x0300 443 #define TXTCR_HEAP_SIZE 0x0308 444 445 #define SHA1_SIZE 20 446 447 struct sha1_hash { 448 u8 hash[SHA1_SIZE]; 449 }; 450 451 struct sinit_mle_data { 452 u32 version; /* currently 6 */ 453 struct sha1_hash bios_acm_id; 454 u32 edx_senter_flags; 455 u64 mseg_valid; 456 struct sha1_hash sinit_hash; 457 struct sha1_hash mle_hash; 458 struct sha1_hash stm_hash; 459 struct sha1_hash lcp_policy_hash; 460 u32 lcp_policy_control; 461 u32 rlp_wakeup_addr; 462 u32 reserved; 463 u32 num_mdrs; 464 u32 mdrs_off; 465 u32 num_vtd_dmars; 466 u32 vtd_dmars_off; 467 } __packed; 468 469 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) 470 { 471 void *heap_base, *heap_ptr, *config; 472 473 if (!tboot_enabled()) 474 return dmar_tbl; 475 476 /* 477 * ACPI tables may not be DMA protected by tboot, so use DMAR copy 478 * SINIT saved in SinitMleData in TXT heap (which is DMA protected) 479 */ 480 481 /* map config space in order to get heap addr */ 482 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * 483 PAGE_SIZE); 484 if (!config) 485 return NULL; 486 487 /* now map TXT heap */ 488 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), 489 *(u64 *)(config + TXTCR_HEAP_SIZE)); 490 iounmap(config); 491 if (!heap_base) 492 return NULL; 493 494 /* walk heap to SinitMleData */ 495 /* skip BiosData */ 496 heap_ptr = heap_base + *(u64 *)heap_base; 497 /* skip OsMleData */ 498 heap_ptr += *(u64 *)heap_ptr; 499 /* skip OsSinitData */ 500 heap_ptr += *(u64 *)heap_ptr; 501 /* now points to SinitMleDataSize; set to SinitMleData */ 502 heap_ptr += sizeof(u64); 503 /* get addr of DMAR table */ 504 dmar_tbl = (struct acpi_table_header *)(heap_ptr + 505 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - 506 sizeof(u64)); 507 508 /* don't unmap heap because dmar.c needs access to this */ 509 510 return dmar_tbl; 511 } 512 513 int tboot_force_iommu(void) 514 { 515 if (!tboot_enabled()) 516 return 0; 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