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 35 #include <asm/trampoline.h> 36 #include <asm/processor.h> 37 #include <asm/bootparam.h> 38 #include <asm/pgtable.h> 39 #include <asm/pgalloc.h> 40 #include <asm/swiotlb.h> 41 #include <asm/fixmap.h> 42 #include <asm/proto.h> 43 #include <asm/setup.h> 44 #include <asm/e820.h> 45 #include <asm/io.h> 46 47 #include "acpi/realmode/wakeup.h" 48 49 /* Global pointer to shared data; NULL means no measured launch. */ 50 struct tboot *tboot __read_mostly; 51 EXPORT_SYMBOL(tboot); 52 53 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */ 54 #define AP_WAIT_TIMEOUT 1 55 56 #undef pr_fmt 57 #define pr_fmt(fmt) "tboot: " fmt 58 59 static u8 tboot_uuid[16] __initdata = TBOOT_UUID; 60 61 void __init tboot_probe(void) 62 { 63 /* Look for valid page-aligned address for shared page. */ 64 if (!boot_params.tboot_addr) 65 return; 66 /* 67 * also verify that it is mapped as we expect it before calling 68 * set_fixmap(), to reduce chance of garbage value causing crash 69 */ 70 if (!e820_any_mapped(boot_params.tboot_addr, 71 boot_params.tboot_addr, E820_RESERVED)) { 72 pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n"); 73 return; 74 } 75 76 /* only a natively booted kernel should be using TXT */ 77 if (paravirt_enabled()) { 78 pr_warning("non-0 tboot_addr but pv_ops is enabled\n"); 79 return; 80 } 81 82 /* Map and check for tboot UUID. */ 83 set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr); 84 tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE); 85 if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) { 86 pr_warning("tboot at 0x%llx is invalid\n", 87 boot_params.tboot_addr); 88 tboot = NULL; 89 return; 90 } 91 if (tboot->version < 5) { 92 pr_warning("tboot version is invalid: %u\n", tboot->version); 93 tboot = NULL; 94 return; 95 } 96 97 pr_info("found shared page at phys addr 0x%llx:\n", 98 boot_params.tboot_addr); 99 pr_debug("version: %d\n", tboot->version); 100 pr_debug("log_addr: 0x%08x\n", tboot->log_addr); 101 pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry); 102 pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base); 103 pr_debug("tboot_size: 0x%x\n", tboot->tboot_size); 104 } 105 106 static pgd_t *tboot_pg_dir; 107 static struct mm_struct tboot_mm = { 108 .mm_rb = RB_ROOT, 109 .pgd = swapper_pg_dir, 110 .mm_users = ATOMIC_INIT(2), 111 .mm_count = ATOMIC_INIT(1), 112 .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem), 113 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), 114 .mmlist = LIST_HEAD_INIT(init_mm.mmlist), 115 }; 116 117 static inline void switch_to_tboot_pt(void) 118 { 119 write_cr3(virt_to_phys(tboot_pg_dir)); 120 } 121 122 static int map_tboot_page(unsigned long vaddr, unsigned long pfn, 123 pgprot_t prot) 124 { 125 pgd_t *pgd; 126 pud_t *pud; 127 pmd_t *pmd; 128 pte_t *pte; 129 130 pgd = pgd_offset(&tboot_mm, vaddr); 131 pud = pud_alloc(&tboot_mm, pgd, vaddr); 132 if (!pud) 133 return -1; 134 pmd = pmd_alloc(&tboot_mm, pud, vaddr); 135 if (!pmd) 136 return -1; 137 pte = pte_alloc_map(&tboot_mm, NULL, pmd, vaddr); 138 if (!pte) 139 return -1; 140 set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); 141 pte_unmap(pte); 142 return 0; 143 } 144 145 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, 146 unsigned long nr) 147 { 148 /* Reuse the original kernel mapping */ 149 tboot_pg_dir = pgd_alloc(&tboot_mm); 150 if (!tboot_pg_dir) 151 return -1; 152 153 for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { 154 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC)) 155 return -1; 156 } 157 158 return 0; 159 } 160 161 static void tboot_create_trampoline(void) 162 { 163 u32 map_base, map_size; 164 165 /* Create identity map for tboot shutdown code. */ 166 map_base = PFN_DOWN(tboot->tboot_base); 167 map_size = PFN_UP(tboot->tboot_size); 168 if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size)) 169 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", 170 map_base, map_size); 171 } 172 173 #ifdef CONFIG_ACPI_SLEEP 174 175 static void add_mac_region(phys_addr_t start, unsigned long size) 176 { 177 struct tboot_mac_region *mr; 178 phys_addr_t end = start + size; 179 180 if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS) 181 panic("tboot: Too many MAC regions\n"); 182 183 if (start && size) { 184 mr = &tboot->mac_regions[tboot->num_mac_regions++]; 185 mr->start = round_down(start, PAGE_SIZE); 186 mr->size = round_up(end, PAGE_SIZE) - mr->start; 187 } 188 } 189 190 static int tboot_setup_sleep(void) 191 { 192 int i; 193 194 tboot->num_mac_regions = 0; 195 196 for (i = 0; i < e820.nr_map; i++) { 197 if ((e820.map[i].type != E820_RAM) 198 && (e820.map[i].type != E820_RESERVED_KERN)) 199 continue; 200 201 add_mac_region(e820.map[i].addr, e820.map[i].size); 202 } 203 204 tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address; 205 206 return 0; 207 } 208 209 #else /* no CONFIG_ACPI_SLEEP */ 210 211 static int tboot_setup_sleep(void) 212 { 213 /* S3 shutdown requested, but S3 not supported by the kernel... */ 214 BUG(); 215 return -1; 216 } 217 218 #endif 219 220 void tboot_shutdown(u32 shutdown_type) 221 { 222 void (*shutdown)(void); 223 224 if (!tboot_enabled()) 225 return; 226 227 /* 228 * if we're being called before the 1:1 mapping is set up then just 229 * return and let the normal shutdown happen; this should only be 230 * due to very early panic() 231 */ 232 if (!tboot_pg_dir) 233 return; 234 235 /* if this is S3 then set regions to MAC */ 236 if (shutdown_type == TB_SHUTDOWN_S3) 237 if (tboot_setup_sleep()) 238 return; 239 240 tboot->shutdown_type = shutdown_type; 241 242 switch_to_tboot_pt(); 243 244 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; 245 shutdown(); 246 247 /* should not reach here */ 248 while (1) 249 halt(); 250 } 251 252 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) 253 { 254 #define TB_COPY_GAS(tbg, g) \ 255 tbg.space_id = g.space_id; \ 256 tbg.bit_width = g.bit_width; \ 257 tbg.bit_offset = g.bit_offset; \ 258 tbg.access_width = g.access_width; \ 259 tbg.address = g.address; 260 261 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); 262 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); 263 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); 264 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); 265 266 /* 267 * We need phys addr of waking vector, but can't use virt_to_phys() on 268 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys 269 * addr. 270 */ 271 tboot->acpi_sinfo.wakeup_vector = fadt->facs + 272 offsetof(struct acpi_table_facs, firmware_waking_vector); 273 } 274 275 void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) 276 { 277 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { 278 /* S0,1,2: */ -1, -1, -1, 279 /* S3: */ TB_SHUTDOWN_S3, 280 /* S4: */ TB_SHUTDOWN_S4, 281 /* S5: */ TB_SHUTDOWN_S5 }; 282 283 if (!tboot_enabled()) 284 return; 285 286 tboot_copy_fadt(&acpi_gbl_FADT); 287 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; 288 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; 289 /* we always use the 32b wakeup vector */ 290 tboot->acpi_sinfo.vector_width = 32; 291 292 if (sleep_state >= ACPI_S_STATE_COUNT || 293 acpi_shutdown_map[sleep_state] == -1) { 294 pr_warning("unsupported sleep state 0x%x\n", sleep_state); 295 return; 296 } 297 298 tboot_shutdown(acpi_shutdown_map[sleep_state]); 299 } 300 301 static atomic_t ap_wfs_count; 302 303 static int tboot_wait_for_aps(int num_aps) 304 { 305 unsigned long timeout; 306 307 timeout = AP_WAIT_TIMEOUT*HZ; 308 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps && 309 timeout) { 310 mdelay(1); 311 timeout--; 312 } 313 314 if (timeout) 315 pr_warning("tboot wait for APs timeout\n"); 316 317 return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps); 318 } 319 320 static int __cpuinit tboot_cpu_callback(struct notifier_block *nfb, 321 unsigned long action, void *hcpu) 322 { 323 switch (action) { 324 case CPU_DYING: 325 atomic_inc(&ap_wfs_count); 326 if (num_online_cpus() == 1) 327 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count))) 328 return NOTIFY_BAD; 329 break; 330 } 331 return NOTIFY_OK; 332 } 333 334 static struct notifier_block tboot_cpu_notifier __cpuinitdata = 335 { 336 .notifier_call = tboot_cpu_callback, 337 }; 338 339 static __init int tboot_late_init(void) 340 { 341 if (!tboot_enabled()) 342 return 0; 343 344 tboot_create_trampoline(); 345 346 atomic_set(&ap_wfs_count, 0); 347 register_hotcpu_notifier(&tboot_cpu_notifier); 348 return 0; 349 } 350 351 late_initcall(tboot_late_init); 352 353 /* 354 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) 355 */ 356 357 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 358 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 359 360 /* # pages for each config regs space - used by fixmap */ 361 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ 362 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) 363 364 /* offsets from pub/priv config space */ 365 #define TXTCR_HEAP_BASE 0x0300 366 #define TXTCR_HEAP_SIZE 0x0308 367 368 #define SHA1_SIZE 20 369 370 struct sha1_hash { 371 u8 hash[SHA1_SIZE]; 372 }; 373 374 struct sinit_mle_data { 375 u32 version; /* currently 6 */ 376 struct sha1_hash bios_acm_id; 377 u32 edx_senter_flags; 378 u64 mseg_valid; 379 struct sha1_hash sinit_hash; 380 struct sha1_hash mle_hash; 381 struct sha1_hash stm_hash; 382 struct sha1_hash lcp_policy_hash; 383 u32 lcp_policy_control; 384 u32 rlp_wakeup_addr; 385 u32 reserved; 386 u32 num_mdrs; 387 u32 mdrs_off; 388 u32 num_vtd_dmars; 389 u32 vtd_dmars_off; 390 } __packed; 391 392 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) 393 { 394 void *heap_base, *heap_ptr, *config; 395 396 if (!tboot_enabled()) 397 return dmar_tbl; 398 399 /* 400 * ACPI tables may not be DMA protected by tboot, so use DMAR copy 401 * SINIT saved in SinitMleData in TXT heap (which is DMA protected) 402 */ 403 404 /* map config space in order to get heap addr */ 405 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * 406 PAGE_SIZE); 407 if (!config) 408 return NULL; 409 410 /* now map TXT heap */ 411 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), 412 *(u64 *)(config + TXTCR_HEAP_SIZE)); 413 iounmap(config); 414 if (!heap_base) 415 return NULL; 416 417 /* walk heap to SinitMleData */ 418 /* skip BiosData */ 419 heap_ptr = heap_base + *(u64 *)heap_base; 420 /* skip OsMleData */ 421 heap_ptr += *(u64 *)heap_ptr; 422 /* skip OsSinitData */ 423 heap_ptr += *(u64 *)heap_ptr; 424 /* now points to SinitMleDataSize; set to SinitMleData */ 425 heap_ptr += sizeof(u64); 426 /* get addr of DMAR table */ 427 dmar_tbl = (struct acpi_table_header *)(heap_ptr + 428 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - 429 sizeof(u64)); 430 431 /* don't unmap heap because dmar.c needs access to this */ 432 433 return dmar_tbl; 434 } 435 436 int tboot_force_iommu(void) 437 { 438 if (!tboot_enabled()) 439 return 0; 440 441 if (no_iommu || swiotlb || dmar_disabled) 442 pr_warning("Forcing Intel-IOMMU to enabled\n"); 443 444 dmar_disabled = 0; 445 #ifdef CONFIG_SWIOTLB 446 swiotlb = 0; 447 #endif 448 no_iommu = 0; 449 450 return 1; 451 } 452