arch/x86/kernel/tboot.c

   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         /* 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         return 0;
 142 }
 143
 144 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
 145                            unsigned long nr)
 146 {
 147         /* Reuse the original kernel mapping */
 148         tboot_pg_dir = pgd_alloc(&tboot_mm);
 149         if (!tboot_pg_dir)
 150                 return -1;
 151
 152         for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
 153                 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
 154                         return -1;
 155         }
 156
 157         return 0;
 158 }
 159
 160 static void tboot_create_trampoline(void)
 161 {
 162         u32 map_base, map_size;
 163
 164         /* Create identity map for tboot shutdown code. */
 165         map_base = PFN_DOWN(tboot->tboot_base);
 166         map_size = PFN_UP(tboot->tboot_size);
 167         if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size))
 168                 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n",
 169                       map_base, map_size);
 170 }
 171
 172 #ifdef CONFIG_ACPI_SLEEP
 173
 174 static void add_mac_region(phys_addr_t start, unsigned long size)
 175 {
 176         struct tboot_mac_region *mr;
 177         phys_addr_t end = start + size;
 178
 179         if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS)
 180                 panic("tboot: Too many MAC regions\n");
 181
 182         if (start && size) {
 183                 mr = &tboot->mac_regions[tboot->num_mac_regions++];
 184                 mr->start = round_down(start, PAGE_SIZE);
 185                 mr->size  = round_up(end, PAGE_SIZE) - mr->start;
 186         }
 187 }
 188
 189 static int tboot_setup_sleep(void)
 190 {
 191         int i;
 192
 193         tboot->num_mac_regions = 0;
 194
 195         for (i = 0; i < e820->nr_map; i++) {
 196                 if ((e820->map[i].type != E820_RAM)
 197                  && (e820->map[i].type != E820_RESERVED_KERN))
 198                         continue;
 199
 200                 add_mac_region(e820->map[i].addr, e820->map[i].size);
 201         }
 202
 203         tboot->acpi_sinfo.kernel_s3_resume_vector =
 204                 real_mode_header->wakeup_start;
 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 static int 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 0;
 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 -1;
 296         }
 297
 298         tboot_shutdown(acpi_shutdown_map[sleep_state]);
 299         return 0;
 300 }
 301
 302 static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b)
 303 {
 304         if (!tboot_enabled())
 305                 return 0;
 306
 307         pr_warning("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)");
 308         return -ENODEV;
 309 }
 310
 311 static atomic_t ap_wfs_count;
 312
 313 static int tboot_wait_for_aps(int num_aps)
 314 {
 315         unsigned long timeout;
 316
 317         timeout = AP_WAIT_TIMEOUT*HZ;
 318         while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
 319                timeout) {
 320                 mdelay(1);
 321                 timeout--;
 322         }
 323
 324         if (timeout)
 325                 pr_warning("tboot wait for APs timeout\n");
 326
 327         return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps);
 328 }
 329
 330 static int tboot_dying_cpu(unsigned int cpu)
 331 {
 332         atomic_inc(&ap_wfs_count);
 333         if (num_online_cpus() == 1) {
 334                 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
 335                         return -EBUSY;
 336         }
 337         return 0;
 338 }
 339
 340 #ifdef CONFIG_DEBUG_FS
 341
 342 #define TBOOT_LOG_UUID  { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \
 343                           0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 }
 344
 345 #define TBOOT_SERIAL_LOG_ADDR   0x60000
 346 #define TBOOT_SERIAL_LOG_SIZE   0x08000
 347 #define LOG_MAX_SIZE_OFF        16
 348 #define LOG_BUF_OFF             24
 349
 350 static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID;
 351
 352 static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos)
 353 {
 354         void __iomem *log_base;
 355         u8 log_uuid[16];
 356         u32 max_size;
 357         void *kbuf;
 358         int ret = -EFAULT;
 359
 360         log_base = ioremap_nocache(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE);
 361         if (!log_base)
 362                 return ret;
 363
 364         memcpy_fromio(log_uuid, log_base, sizeof(log_uuid));
 365         if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid)))
 366                 goto err_iounmap;
 367
 368         max_size = readl(log_base + LOG_MAX_SIZE_OFF);
 369         if (*ppos >= max_size) {
 370                 ret = 0;
 371                 goto err_iounmap;
 372         }
 373
 374         if (*ppos + count > max_size)
 375                 count = max_size - *ppos;
 376
 377         kbuf = kmalloc(count, GFP_KERNEL);
 378         if (!kbuf) {
 379                 ret = -ENOMEM;
 380                 goto err_iounmap;
 381         }
 382
 383         memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count);
 384         if (copy_to_user(user_buf, kbuf, count))
 385                 goto err_kfree;
 386
 387         *ppos += count;
 388
 389         ret = count;
 390
 391 err_kfree:
 392         kfree(kbuf);
 393
 394 err_iounmap:
 395         iounmap(log_base);
 396
 397         return ret;
 398 }
 399
 400 static const struct file_operations tboot_log_fops = {
 401         .read   = tboot_log_read,
 402         .llseek = default_llseek,
 403 };
 404
 405 #endif /* CONFIG_DEBUG_FS */
 406
 407 static __init int tboot_late_init(void)
 408 {
 409         if (!tboot_enabled())
 410                 return 0;
 411
 412         tboot_create_trampoline();
 413
 414         atomic_set(&ap_wfs_count, 0);
 415         cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL,
 416                           tboot_dying_cpu);
 417 #ifdef CONFIG_DEBUG_FS
 418         debugfs_create_file("tboot_log", S_IRUSR,
 419                         arch_debugfs_dir, NULL, &tboot_log_fops);
 420 #endif
 421
 422         acpi_os_set_prepare_sleep(&tboot_sleep);
 423         acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep);
 424         return 0;
 425 }
 426
 427 late_initcall(tboot_late_init);
 428
 429 /*
 430  * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
 431  */
 432
 433 #define TXT_PUB_CONFIG_REGS_BASE       0xfed30000
 434 #define TXT_PRIV_CONFIG_REGS_BASE      0xfed20000
 435
 436 /* # pages for each config regs space - used by fixmap */
 437 #define NR_TXT_CONFIG_PAGES     ((TXT_PUB_CONFIG_REGS_BASE -                \
 438                                   TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
 439
 440 /* offsets from pub/priv config space */
 441 #define TXTCR_HEAP_BASE             0x0300
 442 #define TXTCR_HEAP_SIZE             0x0308
 443
 444 #define SHA1_SIZE      20
 445
 446 struct sha1_hash {
 447         u8 hash[SHA1_SIZE];
 448 };
 449
 450 struct sinit_mle_data {
 451         u32               version;             /* currently 6 */
 452         struct sha1_hash  bios_acm_id;
 453         u32               edx_senter_flags;
 454         u64               mseg_valid;
 455         struct sha1_hash  sinit_hash;
 456         struct sha1_hash  mle_hash;
 457         struct sha1_hash  stm_hash;
 458         struct sha1_hash  lcp_policy_hash;
 459         u32               lcp_policy_control;
 460         u32               rlp_wakeup_addr;
 461         u32               reserved;
 462         u32               num_mdrs;
 463         u32               mdrs_off;
 464         u32               num_vtd_dmars;
 465         u32               vtd_dmars_off;
 466 } __packed;
 467
 468 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
 469 {
 470         void *heap_base, *heap_ptr, *config;
 471
 472         if (!tboot_enabled())
 473                 return dmar_tbl;
 474
 475         /*
 476          * ACPI tables may not be DMA protected by tboot, so use DMAR copy
 477          * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
 478          */
 479
 480         /* map config space in order to get heap addr */
 481         config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
 482                          PAGE_SIZE);
 483         if (!config)
 484                 return NULL;
 485
 486         /* now map TXT heap */
 487         heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
 488                             *(u64 *)(config + TXTCR_HEAP_SIZE));
 489         iounmap(config);
 490         if (!heap_base)
 491                 return NULL;
 492
 493         /* walk heap to SinitMleData */
 494         /* skip BiosData */
 495         heap_ptr = heap_base + *(u64 *)heap_base;
 496         /* skip OsMleData */
 497         heap_ptr += *(u64 *)heap_ptr;
 498         /* skip OsSinitData */
 499         heap_ptr += *(u64 *)heap_ptr;
 500         /* now points to SinitMleDataSize; set to SinitMleData */
 501         heap_ptr += sizeof(u64);
 502         /* get addr of DMAR table */
 503         dmar_tbl = (struct acpi_table_header *)(heap_ptr +
 504                    ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
 505                    sizeof(u64));
 506
 507         /* don't unmap heap because dmar.c needs access to this */
 508
 509         return dmar_tbl;
 510 }
 511
 512 int tboot_force_iommu(void)
 513 {
 514         if (!tboot_enabled())
 515                 return 0;
 516
 517         if (no_iommu || swiotlb || dmar_disabled)
 518                 pr_warning("Forcing Intel-IOMMU to enabled\n");
 519
 520         dmar_disabled = 0;
 521 #ifdef CONFIG_SWIOTLB
 522         swiotlb = 0;
 523 #endif
 524         no_iommu = 0;
 525
 526         return 1;
 527 }