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