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         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.nr_map; i++) {
 192                 if ((e820.map[i].type != E820_RAM)
 193                  && (e820.map[i].type != E820_RESERVED_KERN))
 194                         continue;
 195
 196                 add_mac_region(e820.map[i].addr, e820.map[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, "AP_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 }