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 };
 114
 115 static inline void switch_to_tboot_pt(void)
 116 {
 117         write_cr3(virt_to_phys(tboot_pg_dir));
 118 }
 119
 120 static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
 121                           pgprot_t prot)
 122 {
 123         pgd_t *pgd;
 124         pud_t *pud;
 125         pmd_t *pmd;
 126         pte_t *pte;
 127
 128         pgd = pgd_offset(&tboot_mm, vaddr);
 129         pud = pud_alloc(&tboot_mm, pgd, vaddr);
 130         if (!pud)
 131                 return -1;
 132         pmd = pmd_alloc(&tboot_mm, pud, vaddr);
 133         if (!pmd)
 134                 return -1;
 135         pte = pte_alloc_map(&tboot_mm, NULL, pmd, vaddr);
 136         if (!pte)
 137                 return -1;
 138         set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
 139         pte_unmap(pte);
 140         return 0;
 141 }
 142
 143 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
 144                            unsigned long nr)
 145 {
 146         /* Reuse the original kernel mapping */
 147         tboot_pg_dir = pgd_alloc(&tboot_mm);
 148         if (!tboot_pg_dir)
 149                 return -1;
 150
 151         for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
 152                 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
 153                         return -1;
 154         }
 155
 156         return 0;
 157 }
 158
 159 static void tboot_create_trampoline(void)
 160 {
 161         u32 map_base, map_size;
 162
 163         /* Create identity map for tboot shutdown code. */
 164         map_base = PFN_DOWN(tboot->tboot_base);
 165         map_size = PFN_UP(tboot->tboot_size);
 166         if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size))
 167                 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n",
 168                       map_base, map_size);
 169 }
 170
 171 #ifdef CONFIG_ACPI_SLEEP
 172
 173 static void add_mac_region(phys_addr_t start, unsigned long size)
 174 {
 175         struct tboot_mac_region *mr;
 176         phys_addr_t end = start + size;
 177
 178         if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS)
 179                 panic("tboot: Too many MAC regions\n");
 180
 181         if (start && size) {
 182                 mr = &tboot->mac_regions[tboot->num_mac_regions++];
 183                 mr->start = round_down(start, PAGE_SIZE);
 184                 mr->size  = round_up(end, PAGE_SIZE) - mr->start;
 185         }
 186 }
 187
 188 static int tboot_setup_sleep(void)
 189 {
 190         int i;
 191
 192         tboot->num_mac_regions = 0;
 193
 194         for (i = 0; i < e820.nr_map; i++) {
 195                 if ((e820.map[i].type != E820_RAM)
 196                  && (e820.map[i].type != E820_RESERVED_KERN))
 197                         continue;
 198
 199                 add_mac_region(e820.map[i].addr, e820.map[i].size);
 200         }
 201
 202         tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
 203
 204         return 0;
 205 }
 206
 207 #else /* no CONFIG_ACPI_SLEEP */
 208
 209 static int tboot_setup_sleep(void)
 210 {
 211         /* S3 shutdown requested, but S3 not supported by the kernel... */
 212         BUG();
 213         return -1;
 214 }
 215
 216 #endif
 217
 218 void tboot_shutdown(u32 shutdown_type)
 219 {
 220         void (*shutdown)(void);
 221
 222         if (!tboot_enabled())
 223                 return;
 224
 225         /*
 226          * if we're being called before the 1:1 mapping is set up then just
 227          * return and let the normal shutdown happen; this should only be
 228          * due to very early panic()
 229          */
 230         if (!tboot_pg_dir)
 231                 return;
 232
 233         /* if this is S3 then set regions to MAC */
 234         if (shutdown_type == TB_SHUTDOWN_S3)
 235                 if (tboot_setup_sleep())
 236                         return;
 237
 238         tboot->shutdown_type = shutdown_type;
 239
 240         switch_to_tboot_pt();
 241
 242         shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
 243         shutdown();
 244
 245         /* should not reach here */
 246         while (1)
 247                 halt();
 248 }
 249
 250 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
 251 {
 252 #define TB_COPY_GAS(tbg, g)                     \
 253         tbg.space_id     = g.space_id;          \
 254         tbg.bit_width    = g.bit_width;         \
 255         tbg.bit_offset   = g.bit_offset;        \
 256         tbg.access_width = g.access_width;      \
 257         tbg.address      = g.address;
 258
 259         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
 260         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
 261         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
 262         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);
 263
 264         /*
 265          * We need phys addr of waking vector, but can't use virt_to_phys() on
 266          * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
 267          * addr.
 268          */
 269         tboot->acpi_sinfo.wakeup_vector = fadt->facs +
 270                 offsetof(struct acpi_table_facs, firmware_waking_vector);
 271 }
 272
 273 void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
 274 {
 275         static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
 276                 /* S0,1,2: */ -1, -1, -1,
 277                 /* S3: */ TB_SHUTDOWN_S3,
 278                 /* S4: */ TB_SHUTDOWN_S4,
 279                 /* S5: */ TB_SHUTDOWN_S5 };
 280
 281         if (!tboot_enabled())
 282                 return;
 283
 284         tboot_copy_fadt(&acpi_gbl_FADT);
 285         tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
 286         tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
 287         /* we always use the 32b wakeup vector */
 288         tboot->acpi_sinfo.vector_width = 32;
 289
 290         if (sleep_state >= ACPI_S_STATE_COUNT ||
 291             acpi_shutdown_map[sleep_state] == -1) {
 292                 pr_warning("unsupported sleep state 0x%x\n", sleep_state);
 293                 return;
 294         }
 295
 296         tboot_shutdown(acpi_shutdown_map[sleep_state]);
 297 }
 298
 299 static atomic_t ap_wfs_count;
 300
 301 static int tboot_wait_for_aps(int num_aps)
 302 {
 303         unsigned long timeout;
 304
 305         timeout = AP_WAIT_TIMEOUT*HZ;
 306         while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
 307                timeout) {
 308                 mdelay(1);
 309                 timeout--;
 310         }
 311
 312         if (timeout)
 313                 pr_warning("tboot wait for APs timeout\n");
 314
 315         return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps);
 316 }
 317
 318 static int __cpuinit tboot_cpu_callback(struct notifier_block *nfb,
 319                         unsigned long action, void *hcpu)
 320 {
 321         switch (action) {
 322         case CPU_DYING:
 323                 atomic_inc(&ap_wfs_count);
 324                 if (num_online_cpus() == 1)
 325                         if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
 326                                 return NOTIFY_BAD;
 327                 break;
 328         }
 329         return NOTIFY_OK;
 330 }
 331
 332 static struct notifier_block tboot_cpu_notifier __cpuinitdata =
 333 {
 334         .notifier_call = tboot_cpu_callback,
 335 };
 336
 337 static __init int tboot_late_init(void)
 338 {
 339         if (!tboot_enabled())
 340                 return 0;
 341
 342         tboot_create_trampoline();
 343
 344         atomic_set(&ap_wfs_count, 0);
 345         register_hotcpu_notifier(&tboot_cpu_notifier);
 346         return 0;
 347 }
 348
 349 late_initcall(tboot_late_init);
 350
 351 /*
 352  * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
 353  */
 354
 355 #define TXT_PUB_CONFIG_REGS_BASE       0xfed30000
 356 #define TXT_PRIV_CONFIG_REGS_BASE      0xfed20000
 357
 358 /* # pages for each config regs space - used by fixmap */
 359 #define NR_TXT_CONFIG_PAGES     ((TXT_PUB_CONFIG_REGS_BASE -                \
 360                                   TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
 361
 362 /* offsets from pub/priv config space */
 363 #define TXTCR_HEAP_BASE             0x0300
 364 #define TXTCR_HEAP_SIZE             0x0308
 365
 366 #define SHA1_SIZE      20
 367
 368 struct sha1_hash {
 369         u8 hash[SHA1_SIZE];
 370 };
 371
 372 struct sinit_mle_data {
 373         u32               version;             /* currently 6 */
 374         struct sha1_hash  bios_acm_id;
 375         u32               edx_senter_flags;
 376         u64               mseg_valid;
 377         struct sha1_hash  sinit_hash;
 378         struct sha1_hash  mle_hash;
 379         struct sha1_hash  stm_hash;
 380         struct sha1_hash  lcp_policy_hash;
 381         u32               lcp_policy_control;
 382         u32               rlp_wakeup_addr;
 383         u32               reserved;
 384         u32               num_mdrs;
 385         u32               mdrs_off;
 386         u32               num_vtd_dmars;
 387         u32               vtd_dmars_off;
 388 } __packed;
 389
 390 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
 391 {
 392         void *heap_base, *heap_ptr, *config;
 393
 394         if (!tboot_enabled())
 395                 return dmar_tbl;
 396
 397         /*
 398          * ACPI tables may not be DMA protected by tboot, so use DMAR copy
 399          * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
 400          */
 401
 402         /* map config space in order to get heap addr */
 403         config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
 404                          PAGE_SIZE);
 405         if (!config)
 406                 return NULL;
 407
 408         /* now map TXT heap */
 409         heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
 410                             *(u64 *)(config + TXTCR_HEAP_SIZE));
 411         iounmap(config);
 412         if (!heap_base)
 413                 return NULL;
 414
 415         /* walk heap to SinitMleData */
 416         /* skip BiosData */
 417         heap_ptr = heap_base + *(u64 *)heap_base;
 418         /* skip OsMleData */
 419         heap_ptr += *(u64 *)heap_ptr;
 420         /* skip OsSinitData */
 421         heap_ptr += *(u64 *)heap_ptr;
 422         /* now points to SinitMleDataSize; set to SinitMleData */
 423         heap_ptr += sizeof(u64);
 424         /* get addr of DMAR table */
 425         dmar_tbl = (struct acpi_table_header *)(heap_ptr +
 426                    ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
 427                    sizeof(u64));
 428
 429         /* don't unmap heap because dmar.c needs access to this */
 430
 431         return dmar_tbl;
 432 }
 433
 434 int tboot_force_iommu(void)
 435 {
 436         if (!tboot_enabled())
 437                 return 0;
 438
 439         if (no_iommu || swiotlb || dmar_disabled)
 440                 pr_warning("Forcing Intel-IOMMU to enabled\n");
 441
 442         dmar_disabled = 0;
 443 #ifdef CONFIG_SWIOTLB
 444         swiotlb = 0;
 445 #endif
 446         no_iommu = 0;
 447
 448         return 1;
 449 }