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/delay.h>
  26 #include <linux/sched.h>
  27 #include <linux/init.h>
  28 #include <linux/dmar.h>
  29 #include <linux/cpu.h>
  30 #include <linux/pfn.h>
  31 #include <linux/mm.h>
  32 #include <linux/tboot.h>
  33
  34 #include <asm/trampoline.h>
  35 #include <asm/processor.h>
  36 #include <asm/bootparam.h>
  37 #include <asm/pgtable.h>
  38 #include <asm/pgalloc.h>
  39 #include <asm/fixmap.h>
  40 #include <asm/proto.h>
  41 #include <asm/setup.h>
  42 #include <asm/e820.h>
  43 #include <asm/io.h>
  44
  45 #include "acpi/realmode/wakeup.h"
  46
  47 /* Global pointer to shared data; NULL means no measured launch. */
  48 struct tboot *tboot __read_mostly;
  49 EXPORT_SYMBOL(tboot);
  50
  51 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
  52 #define AP_WAIT_TIMEOUT         1
  53
  54 #undef pr_fmt
  55 #define pr_fmt(fmt)     "tboot: " fmt
  56
  57 static u8 tboot_uuid[16] __initdata = TBOOT_UUID;
  58
  59 void __init tboot_probe(void)
  60 {
  61         /* Look for valid page-aligned address for shared page. */
  62         if (!boot_params.tboot_addr)
  63                 return;
  64         /*
  65          * also verify that it is mapped as we expect it before calling
  66          * set_fixmap(), to reduce chance of garbage value causing crash
  67          */
  68         if (!e820_any_mapped(boot_params.tboot_addr,
  69                              boot_params.tboot_addr, E820_RESERVED)) {
  70                 pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n");
  71                 return;
  72         }
  73
  74         /* only a natively booted kernel should be using TXT */
  75         if (paravirt_enabled()) {
  76                 pr_warning("non-0 tboot_addr but pv_ops is enabled\n");
  77                 return;
  78         }
  79
  80         /* Map and check for tboot UUID. */
  81         set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
  82         tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE);
  83         if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
  84                 pr_warning("tboot at 0x%llx is invalid\n",
  85                            boot_params.tboot_addr);
  86                 tboot = NULL;
  87                 return;
  88         }
  89         if (tboot->version < 5) {
  90                 pr_warning("tboot version is invalid: %u\n", tboot->version);
  91                 tboot = NULL;
  92                 return;
  93         }
  94
  95         pr_info("found shared page at phys addr 0x%llx:\n",
  96                 boot_params.tboot_addr);
  97         pr_debug("version: %d\n", tboot->version);
  98         pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
  99         pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
 100         pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
 101         pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
 102 }
 103
 104 static pgd_t *tboot_pg_dir;
 105 static struct mm_struct tboot_mm = {
 106         .mm_rb          = RB_ROOT,
 107         .pgd            = swapper_pg_dir,
 108         .mm_users       = ATOMIC_INIT(2),
 109         .mm_count       = ATOMIC_INIT(1),
 110         .mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
 111         .page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
 112         .mmlist         = LIST_HEAD_INIT(init_mm.mmlist),
 113         .cpu_vm_mask    = CPU_MASK_ALL,
 114 };
 115
 116 static inline void switch_to_tboot_pt(void)
 117 {
 118         write_cr3(virt_to_phys(tboot_pg_dir));
 119 }
 120
 121 static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
 122                           pgprot_t prot)
 123 {
 124         pgd_t *pgd;
 125         pud_t *pud;
 126         pmd_t *pmd;
 127         pte_t *pte;
 128
 129         pgd = pgd_offset(&tboot_mm, vaddr);
 130         pud = pud_alloc(&tboot_mm, pgd, 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 (start && size) {
 180                 mr = &tboot->mac_regions[tboot->num_mac_regions++];
 181                 mr->start = round_down(start, PAGE_SIZE);
 182                 mr->size  = round_up(end, PAGE_SIZE) - mr->start;
 183         }
 184 }
 185
 186 static int tboot_setup_sleep(void)
 187 {
 188         tboot->num_mac_regions = 0;
 189
 190         /* S3 resume code */
 191         add_mac_region(acpi_wakeup_address, WAKEUP_SIZE);
 192
 193 #ifdef CONFIG_X86_TRAMPOLINE
 194         /* AP trampoline code */
 195         add_mac_region(virt_to_phys(trampoline_base), TRAMPOLINE_SIZE);
 196 #endif
 197
 198         /* kernel code + data + bss */
 199         add_mac_region(virt_to_phys(_text), _end - _text);
 200
 201         tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
 202
 203         return 0;
 204 }
 205
 206 #else /* no CONFIG_ACPI_SLEEP */
 207
 208 static int tboot_setup_sleep(void)
 209 {
 210         /* S3 shutdown requested, but S3 not supported by the kernel... */
 211         BUG();
 212         return -1;
 213 }
 214
 215 #endif
 216
 217 void tboot_shutdown(u32 shutdown_type)
 218 {
 219         void (*shutdown)(void);
 220
 221         if (!tboot_enabled())
 222                 return;
 223
 224         /*
 225          * if we're being called before the 1:1 mapping is set up then just
 226          * return and let the normal shutdown happen; this should only be
 227          * due to very early panic()
 228          */
 229         if (!tboot_pg_dir)
 230                 return;
 231
 232         /* if this is S3 then set regions to MAC */
 233         if (shutdown_type == TB_SHUTDOWN_S3)
 234                 if (tboot_setup_sleep())
 235                         return;
 236
 237         tboot->shutdown_type = shutdown_type;
 238
 239         switch_to_tboot_pt();
 240
 241         shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
 242         shutdown();
 243
 244         /* should not reach here */
 245         while (1)
 246                 halt();
 247 }
 248
 249 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
 250 {
 251 #define TB_COPY_GAS(tbg, g)                     \
 252         tbg.space_id     = g.space_id;          \
 253         tbg.bit_width    = g.bit_width;         \
 254         tbg.bit_offset   = g.bit_offset;        \
 255         tbg.access_width = g.access_width;      \
 256         tbg.address      = g.address;
 257
 258         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
 259         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
 260         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
 261         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);
 262
 263         /*
 264          * We need phys addr of waking vector, but can't use virt_to_phys() on
 265          * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
 266          * addr.
 267          */
 268         tboot->acpi_sinfo.wakeup_vector = fadt->facs +
 269                 offsetof(struct acpi_table_facs, firmware_waking_vector);
 270 }
 271
 272 void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
 273 {
 274         static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
 275                 /* S0,1,2: */ -1, -1, -1,
 276                 /* S3: */ TB_SHUTDOWN_S3,
 277                 /* S4: */ TB_SHUTDOWN_S4,
 278                 /* S5: */ TB_SHUTDOWN_S5 };
 279
 280         if (!tboot_enabled())
 281                 return;
 282
 283         tboot_copy_fadt(&acpi_gbl_FADT);
 284         tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
 285         tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
 286         /* we always use the 32b wakeup vector */
 287         tboot->acpi_sinfo.vector_width = 32;
 288
 289         if (sleep_state >= ACPI_S_STATE_COUNT ||
 290             acpi_shutdown_map[sleep_state] == -1) {
 291                 pr_warning("unsupported sleep state 0x%x\n", sleep_state);
 292                 return;
 293         }
 294
 295         tboot_shutdown(acpi_shutdown_map[sleep_state]);
 296 }
 297
 298 static atomic_t ap_wfs_count;
 299
 300 static int tboot_wait_for_aps(int num_aps)
 301 {
 302         unsigned long timeout;
 303
 304         timeout = AP_WAIT_TIMEOUT*HZ;
 305         while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
 306                timeout) {
 307                 mdelay(1);
 308                 timeout--;
 309         }
 310
 311         if (timeout)
 312                 pr_warning("tboot wait for APs timeout\n");
 313
 314         return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps);
 315 }
 316
 317 static int __cpuinit tboot_cpu_callback(struct notifier_block *nfb,
 318                         unsigned long action, void *hcpu)
 319 {
 320         switch (action) {
 321         case CPU_DYING:
 322                 atomic_inc(&ap_wfs_count);
 323                 if (num_online_cpus() == 1)
 324                         if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
 325                                 return NOTIFY_BAD;
 326                 break;
 327         }
 328         return NOTIFY_OK;
 329 }
 330
 331 static struct notifier_block tboot_cpu_notifier __cpuinitdata =
 332 {
 333         .notifier_call = tboot_cpu_callback,
 334 };
 335
 336 static __init int tboot_late_init(void)
 337 {
 338         if (!tboot_enabled())
 339                 return 0;
 340
 341         tboot_create_trampoline();
 342
 343         atomic_set(&ap_wfs_count, 0);
 344         register_hotcpu_notifier(&tboot_cpu_notifier);
 345         return 0;
 346 }
 347
 348 late_initcall(tboot_late_init);
 349
 350 /*
 351  * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
 352  */
 353
 354 #define TXT_PUB_CONFIG_REGS_BASE       0xfed30000
 355 #define TXT_PRIV_CONFIG_REGS_BASE      0xfed20000
 356
 357 /* # pages for each config regs space - used by fixmap */
 358 #define NR_TXT_CONFIG_PAGES     ((TXT_PUB_CONFIG_REGS_BASE -                \
 359                                   TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
 360
 361 /* offsets from pub/priv config space */
 362 #define TXTCR_HEAP_BASE             0x0300
 363 #define TXTCR_HEAP_SIZE             0x0308
 364
 365 #define SHA1_SIZE      20
 366
 367 struct sha1_hash {
 368         u8 hash[SHA1_SIZE];
 369 };
 370
 371 struct sinit_mle_data {
 372         u32               version;             /* currently 6 */
 373         struct sha1_hash  bios_acm_id;
 374         u32               edx_senter_flags;
 375         u64               mseg_valid;
 376         struct sha1_hash  sinit_hash;
 377         struct sha1_hash  mle_hash;
 378         struct sha1_hash  stm_hash;
 379         struct sha1_hash  lcp_policy_hash;
 380         u32               lcp_policy_control;
 381         u32               rlp_wakeup_addr;
 382         u32               reserved;
 383         u32               num_mdrs;
 384         u32               mdrs_off;
 385         u32               num_vtd_dmars;
 386         u32               vtd_dmars_off;
 387 } __packed;
 388
 389 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
 390 {
 391         void *heap_base, *heap_ptr, *config;
 392
 393         if (!tboot_enabled())
 394                 return dmar_tbl;
 395
 396         /*
 397          * ACPI tables may not be DMA protected by tboot, so use DMAR copy
 398          * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
 399          */
 400
 401         /* map config space in order to get heap addr */
 402         config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
 403                          PAGE_SIZE);
 404         if (!config)
 405                 return NULL;
 406
 407         /* now map TXT heap */
 408         heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
 409                             *(u64 *)(config + TXTCR_HEAP_SIZE));
 410         iounmap(config);
 411         if (!heap_base)
 412                 return NULL;
 413
 414         /* walk heap to SinitMleData */
 415         /* skip BiosData */
 416         heap_ptr = heap_base + *(u64 *)heap_base;
 417         /* skip OsMleData */
 418         heap_ptr += *(u64 *)heap_ptr;
 419         /* skip OsSinitData */
 420         heap_ptr += *(u64 *)heap_ptr;
 421         /* now points to SinitMleDataSize; set to SinitMleData */
 422         heap_ptr += sizeof(u64);
 423         /* get addr of DMAR table */
 424         dmar_tbl = (struct acpi_table_header *)(heap_ptr +
 425                    ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
 426                    sizeof(u64));
 427
 428         /* don't unmap heap because dmar.c needs access to this */
 429
 430         return dmar_tbl;
 431 }
 432
 433 int tboot_force_iommu(void)
 434 {
 435         if (!tboot_enabled())
 436                 return 0;
 437
 438         if (no_iommu || swiotlb || dmar_disabled)
 439                 pr_warning("Forcing Intel-IOMMU to enabled\n");
 440
 441         dmar_disabled = 0;
 442 #ifdef CONFIG_SWIOTLB
 443         swiotlb = 0;
 444 #endif
 445         no_iommu = 0;
 446
 447         return 1;
 448 }