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
  35 #include <asm/realmode.h>
  36 #include <asm/processor.h>
  37 #include <asm/bootparam.h>
  38 #include <asm/pgtable.h>
  39 #include <asm/pgalloc.h>
  40 #include <asm/swiotlb.h>
  41 #include <asm/fixmap.h>
  42 #include <asm/proto.h>
  43 #include <asm/setup.h>
  44 #include <asm/e820.h>
  45 #include <asm/io.h>
  46
  47 #include "../realmode/rm/wakeup.h"
  48
  49 /* Global pointer to shared data; NULL means no measured launch. */
  50 struct tboot *tboot __read_mostly;
  51 EXPORT_SYMBOL(tboot);
  52
  53 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
  54 #define AP_WAIT_TIMEOUT         1
  55
  56 #undef pr_fmt
  57 #define pr_fmt(fmt)     "tboot: " fmt
  58
  59 static u8 tboot_uuid[16] __initdata = TBOOT_UUID;
  60
  61 void __init tboot_probe(void)
  62 {
  63         /* Look for valid page-aligned address for shared page. */
  64         if (!boot_params.tboot_addr)
  65                 return;
  66         /*
  67          * also verify that it is mapped as we expect it before calling
  68          * set_fixmap(), to reduce chance of garbage value causing crash
  69          */
  70         if (!e820_any_mapped(boot_params.tboot_addr,
  71                              boot_params.tboot_addr, E820_RESERVED)) {
  72                 pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n");
  73                 return;
  74         }
  75
  76         /* only a natively booted kernel should be using TXT */
  77         if (paravirt_enabled()) {
  78                 pr_warning("non-0 tboot_addr but pv_ops is enabled\n");
  79                 return;
  80         }
  81
  82         /* Map and check for tboot UUID. */
  83         set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
  84         tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE);
  85         if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
  86                 pr_warning("tboot at 0x%llx is invalid\n",
  87                            boot_params.tboot_addr);
  88                 tboot = NULL;
  89                 return;
  90         }
  91         if (tboot->version < 5) {
  92                 pr_warning("tboot version is invalid: %u\n", tboot->version);
  93                 tboot = NULL;
  94                 return;
  95         }
  96
  97         pr_info("found shared page at phys addr 0x%llx:\n",
  98                 boot_params.tboot_addr);
  99         pr_debug("version: %d\n", tboot->version);
 100         pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
 101         pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
 102         pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
 103         pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
 104 }
 105
 106 static pgd_t *tboot_pg_dir;
 107 static struct mm_struct tboot_mm = {
 108         .mm_rb          = RB_ROOT,
 109         .pgd            = swapper_pg_dir,
 110         .mm_users       = ATOMIC_INIT(2),
 111         .mm_count       = ATOMIC_INIT(1),
 112         .mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
 113         .page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
 114         .mmlist         = LIST_HEAD_INIT(init_mm.mmlist),
 115 };
 116
 117 static inline void switch_to_tboot_pt(void)
 118 {
 119         write_cr3(virt_to_phys(tboot_pg_dir));
 120 }
 121
 122 static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
 123                           pgprot_t prot)
 124 {
 125         pgd_t *pgd;
 126         pud_t *pud;
 127         pmd_t *pmd;
 128         pte_t *pte;
 129
 130         pgd = pgd_offset(&tboot_mm, vaddr);
 131         pud = pud_alloc(&tboot_mm, pgd, vaddr);
 132         if (!pud)
 133                 return -1;
 134         pmd = pmd_alloc(&tboot_mm, pud, vaddr);
 135         if (!pmd)
 136                 return -1;
 137         pte = pte_alloc_map(&tboot_mm, NULL, pmd, vaddr);
 138         if (!pte)
 139                 return -1;
 140         set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
 141         pte_unmap(pte);
 142         return 0;
 143 }
 144
 145 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
 146                            unsigned long nr)
 147 {
 148         /* Reuse the original kernel mapping */
 149         tboot_pg_dir = pgd_alloc(&tboot_mm);
 150         if (!tboot_pg_dir)
 151                 return -1;
 152
 153         for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
 154                 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
 155                         return -1;
 156         }
 157
 158         return 0;
 159 }
 160
 161 static void tboot_create_trampoline(void)
 162 {
 163         u32 map_base, map_size;
 164
 165         /* Create identity map for tboot shutdown code. */
 166         map_base = PFN_DOWN(tboot->tboot_base);
 167         map_size = PFN_UP(tboot->tboot_size);
 168         if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size))
 169                 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n",
 170                       map_base, map_size);
 171 }
 172
 173 #ifdef CONFIG_ACPI_SLEEP
 174
 175 static void add_mac_region(phys_addr_t start, unsigned long size)
 176 {
 177         struct tboot_mac_region *mr;
 178         phys_addr_t end = start + size;
 179
 180         if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS)
 181                 panic("tboot: Too many MAC regions\n");
 182
 183         if (start && size) {
 184                 mr = &tboot->mac_regions[tboot->num_mac_regions++];
 185                 mr->start = round_down(start, PAGE_SIZE);
 186                 mr->size  = round_up(end, PAGE_SIZE) - mr->start;
 187         }
 188 }
 189
 190 static int tboot_setup_sleep(void)
 191 {
 192         int i;
 193
 194         tboot->num_mac_regions = 0;
 195
 196         for (i = 0; i < e820.nr_map; i++) {
 197                 if ((e820.map[i].type != E820_RAM)
 198                  && (e820.map[i].type != E820_RESERVED_KERN))
 199                         continue;
 200
 201                 add_mac_region(e820.map[i].addr, e820.map[i].size);
 202         }
 203
 204         tboot->acpi_sinfo.kernel_s3_resume_vector =
 205                 real_mode_header->wakeup_start;
 206
 207         return 0;
 208 }
 209
 210 #else /* no CONFIG_ACPI_SLEEP */
 211
 212 static int tboot_setup_sleep(void)
 213 {
 214         /* S3 shutdown requested, but S3 not supported by the kernel... */
 215         BUG();
 216         return -1;
 217 }
 218
 219 #endif
 220
 221 void tboot_shutdown(u32 shutdown_type)
 222 {
 223         void (*shutdown)(void);
 224
 225         if (!tboot_enabled())
 226                 return;
 227
 228         /*
 229          * if we're being called before the 1:1 mapping is set up then just
 230          * return and let the normal shutdown happen; this should only be
 231          * due to very early panic()
 232          */
 233         if (!tboot_pg_dir)
 234                 return;
 235
 236         /* if this is S3 then set regions to MAC */
 237         if (shutdown_type == TB_SHUTDOWN_S3)
 238                 if (tboot_setup_sleep())
 239                         return;
 240
 241         tboot->shutdown_type = shutdown_type;
 242
 243         switch_to_tboot_pt();
 244
 245         shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
 246         shutdown();
 247
 248         /* should not reach here */
 249         while (1)
 250                 halt();
 251 }
 252
 253 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
 254 {
 255 #define TB_COPY_GAS(tbg, g)                     \
 256         tbg.space_id     = g.space_id;          \
 257         tbg.bit_width    = g.bit_width;         \
 258         tbg.bit_offset   = g.bit_offset;        \
 259         tbg.access_width = g.access_width;      \
 260         tbg.address      = g.address;
 261
 262         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
 263         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
 264         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
 265         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);
 266
 267         /*
 268          * We need phys addr of waking vector, but can't use virt_to_phys() on
 269          * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
 270          * addr.
 271          */
 272         tboot->acpi_sinfo.wakeup_vector = fadt->facs +
 273                 offsetof(struct acpi_table_facs, firmware_waking_vector);
 274 }
 275
 276 static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
 277 {
 278         static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
 279                 /* S0,1,2: */ -1, -1, -1,
 280                 /* S3: */ TB_SHUTDOWN_S3,
 281                 /* S4: */ TB_SHUTDOWN_S4,
 282                 /* S5: */ TB_SHUTDOWN_S5 };
 283
 284         if (!tboot_enabled())
 285                 return 0;
 286
 287         tboot_copy_fadt(&acpi_gbl_FADT);
 288         tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
 289         tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
 290         /* we always use the 32b wakeup vector */
 291         tboot->acpi_sinfo.vector_width = 32;
 292
 293         if (sleep_state >= ACPI_S_STATE_COUNT ||
 294             acpi_shutdown_map[sleep_state] == -1) {
 295                 pr_warning("unsupported sleep state 0x%x\n", sleep_state);
 296                 return -1;
 297         }
 298
 299         tboot_shutdown(acpi_shutdown_map[sleep_state]);
 300         return 0;
 301 }
 302
 303 static atomic_t ap_wfs_count;
 304
 305 static int tboot_wait_for_aps(int num_aps)
 306 {
 307         unsigned long timeout;
 308
 309         timeout = AP_WAIT_TIMEOUT*HZ;
 310         while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
 311                timeout) {
 312                 mdelay(1);
 313                 timeout--;
 314         }
 315
 316         if (timeout)
 317                 pr_warning("tboot wait for APs timeout\n");
 318
 319         return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps);
 320 }
 321
 322 static int __cpuinit tboot_cpu_callback(struct notifier_block *nfb,
 323                         unsigned long action, void *hcpu)
 324 {
 325         switch (action) {
 326         case CPU_DYING:
 327                 atomic_inc(&ap_wfs_count);
 328                 if (num_online_cpus() == 1)
 329                         if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
 330                                 return NOTIFY_BAD;
 331                 break;
 332         }
 333         return NOTIFY_OK;
 334 }
 335
 336 static struct notifier_block tboot_cpu_notifier __cpuinitdata =
 337 {
 338         .notifier_call = tboot_cpu_callback,
 339 };
 340
 341 static __init int tboot_late_init(void)
 342 {
 343         if (!tboot_enabled())
 344                 return 0;
 345
 346         tboot_create_trampoline();
 347
 348         atomic_set(&ap_wfs_count, 0);
 349         register_hotcpu_notifier(&tboot_cpu_notifier);
 350
 351         acpi_os_set_prepare_sleep(&tboot_sleep);
 352         return 0;
 353 }
 354
 355 late_initcall(tboot_late_init);
 356
 357 /*
 358  * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
 359  */
 360
 361 #define TXT_PUB_CONFIG_REGS_BASE       0xfed30000
 362 #define TXT_PRIV_CONFIG_REGS_BASE      0xfed20000
 363
 364 /* # pages for each config regs space - used by fixmap */
 365 #define NR_TXT_CONFIG_PAGES     ((TXT_PUB_CONFIG_REGS_BASE -                \
 366                                   TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
 367
 368 /* offsets from pub/priv config space */
 369 #define TXTCR_HEAP_BASE             0x0300
 370 #define TXTCR_HEAP_SIZE             0x0308
 371
 372 #define SHA1_SIZE      20
 373
 374 struct sha1_hash {
 375         u8 hash[SHA1_SIZE];
 376 };
 377
 378 struct sinit_mle_data {
 379         u32               version;             /* currently 6 */
 380         struct sha1_hash  bios_acm_id;
 381         u32               edx_senter_flags;
 382         u64               mseg_valid;
 383         struct sha1_hash  sinit_hash;
 384         struct sha1_hash  mle_hash;
 385         struct sha1_hash  stm_hash;
 386         struct sha1_hash  lcp_policy_hash;
 387         u32               lcp_policy_control;
 388         u32               rlp_wakeup_addr;
 389         u32               reserved;
 390         u32               num_mdrs;
 391         u32               mdrs_off;
 392         u32               num_vtd_dmars;
 393         u32               vtd_dmars_off;
 394 } __packed;
 395
 396 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
 397 {
 398         void *heap_base, *heap_ptr, *config;
 399
 400         if (!tboot_enabled())
 401                 return dmar_tbl;
 402
 403         /*
 404          * ACPI tables may not be DMA protected by tboot, so use DMAR copy
 405          * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
 406          */
 407
 408         /* map config space in order to get heap addr */
 409         config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
 410                          PAGE_SIZE);
 411         if (!config)
 412                 return NULL;
 413
 414         /* now map TXT heap */
 415         heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
 416                             *(u64 *)(config + TXTCR_HEAP_SIZE));
 417         iounmap(config);
 418         if (!heap_base)
 419                 return NULL;
 420
 421         /* walk heap to SinitMleData */
 422         /* skip BiosData */
 423         heap_ptr = heap_base + *(u64 *)heap_base;
 424         /* skip OsMleData */
 425         heap_ptr += *(u64 *)heap_ptr;
 426         /* skip OsSinitData */
 427         heap_ptr += *(u64 *)heap_ptr;
 428         /* now points to SinitMleDataSize; set to SinitMleData */
 429         heap_ptr += sizeof(u64);
 430         /* get addr of DMAR table */
 431         dmar_tbl = (struct acpi_table_header *)(heap_ptr +
 432                    ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
 433                    sizeof(u64));
 434
 435         /* don't unmap heap because dmar.c needs access to this */
 436
 437         return dmar_tbl;
 438 }
 439
 440 int tboot_force_iommu(void)
 441 {
 442         if (!tboot_enabled())
 443                 return 0;
 444
 445         if (no_iommu || swiotlb || dmar_disabled)
 446                 pr_warning("Forcing Intel-IOMMU to enabled\n");
 447
 448         dmar_disabled = 0;
 449 #ifdef CONFIG_SWIOTLB
 450         swiotlb = 0;
 451 #endif
 452         no_iommu = 0;
 453
 454         return 1;
 455 }