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   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
  50 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
  51 #define AP_WAIT_TIMEOUT         1
  52
  53 #undef pr_fmt
  54 #define pr_fmt(fmt)     "tboot: " fmt
  55
  56 static u8 tboot_uuid[16] __initdata = TBOOT_UUID;
  57
  58 void __init tboot_probe(void)
  59 {
  60         /* Look for valid page-aligned address for shared page. */
  61         if (!boot_params.tboot_addr)
  62                 return;
  63         /*
  64          * also verify that it is mapped as we expect it before calling
  65          * set_fixmap(), to reduce chance of garbage value causing crash
  66          */
  67         if (!e820_any_mapped(boot_params.tboot_addr,
  68                              boot_params.tboot_addr, E820_RESERVED)) {
  69                 pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n");
  70                 return;
  71         }
  72
  73         /* only a natively booted kernel should be using TXT */
  74         if (paravirt_enabled()) {
  75                 pr_warning("non-0 tboot_addr but pv_ops is enabled\n");
  76                 return;
  77         }
  78
  79         /* Map and check for tboot UUID. */
  80         set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
  81         tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE);
  82         if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
  83                 pr_warning("tboot at 0x%llx is invalid\n",
  84                            boot_params.tboot_addr);
  85                 tboot = NULL;
  86                 return;
  87         }
  88         if (tboot->version < 5) {
  89                 pr_warning("tboot version is invalid: %u\n", tboot->version);
  90                 tboot = NULL;
  91                 return;
  92         }
  93
  94         pr_info("found shared page at phys addr 0x%llx:\n",
  95                 boot_params.tboot_addr);
  96         pr_debug("version: %d\n", tboot->version);
  97         pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
  98         pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
  99         pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
 100         pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
 101 }
 102
 103 static pgd_t *tboot_pg_dir;
 104 static struct mm_struct tboot_mm = {
 105         .mm_rb          = RB_ROOT,
 106         .pgd            = swapper_pg_dir,
 107         .mm_users       = ATOMIC_INIT(2),
 108         .mm_count       = ATOMIC_INIT(1),
 109         .mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
 110         .page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
 111         .mmlist         = LIST_HEAD_INIT(init_mm.mmlist),
 112         .cpu_vm_mask    = CPU_MASK_ALL,
 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, 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 (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         tboot->num_mac_regions = 0;
 188
 189         /* S3 resume code */
 190         add_mac_region(acpi_wakeup_address, WAKEUP_SIZE);
 191
 192 #ifdef CONFIG_X86_TRAMPOLINE
 193         /* AP trampoline code */
 194         add_mac_region(virt_to_phys(trampoline_base), TRAMPOLINE_SIZE);
 195 #endif
 196
 197         /* kernel code + data + bss */
 198         add_mac_region(virt_to_phys(_text), _end - _text);
 199
 200         tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
 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 void 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;
 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;
 292         }
 293
 294         tboot_shutdown(acpi_shutdown_map[sleep_state]);
 295 }
 296
 297 static atomic_t ap_wfs_count;
 298
 299 static int tboot_wait_for_aps(int num_aps)
 300 {
 301         unsigned long timeout;
 302
 303         timeout = AP_WAIT_TIMEOUT*HZ;
 304         while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
 305                timeout) {
 306                 mdelay(1);
 307                 timeout--;
 308         }
 309
 310         if (timeout)
 311                 pr_warning("tboot wait for APs timeout\n");
 312
 313         return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps);
 314 }
 315
 316 static int __cpuinit tboot_cpu_callback(struct notifier_block *nfb,
 317                         unsigned long action, void *hcpu)
 318 {
 319         switch (action) {
 320         case CPU_DYING:
 321                 atomic_inc(&ap_wfs_count);
 322                 if (num_online_cpus() == 1)
 323                         if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
 324                                 return NOTIFY_BAD;
 325                 break;
 326         }
 327         return NOTIFY_OK;
 328 }
 329
 330 static struct notifier_block tboot_cpu_notifier __cpuinitdata =
 331 {
 332         .notifier_call = tboot_cpu_callback,
 333 };
 334
 335 static __init int tboot_late_init(void)
 336 {
 337         if (!tboot_enabled())
 338                 return 0;
 339
 340         tboot_create_trampoline();
 341
 342         atomic_set(&ap_wfs_count, 0);
 343         register_hotcpu_notifier(&tboot_cpu_notifier);
 344         return 0;
 345 }
 346
 347 late_initcall(tboot_late_init);
 348
 349 /*
 350  * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
 351  */
 352
 353 #define TXT_PUB_CONFIG_REGS_BASE       0xfed30000
 354 #define TXT_PRIV_CONFIG_REGS_BASE      0xfed20000
 355
 356 /* # pages for each config regs space - used by fixmap */
 357 #define NR_TXT_CONFIG_PAGES     ((TXT_PUB_CONFIG_REGS_BASE -                \
 358                                   TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
 359
 360 /* offsets from pub/priv config space */
 361 #define TXTCR_HEAP_BASE             0x0300
 362 #define TXTCR_HEAP_SIZE             0x0308
 363
 364 #define SHA1_SIZE      20
 365
 366 struct sha1_hash {
 367         u8 hash[SHA1_SIZE];
 368 };
 369
 370 struct sinit_mle_data {
 371         u32               version;             /* currently 6 */
 372         struct sha1_hash  bios_acm_id;
 373         u32               edx_senter_flags;
 374         u64               mseg_valid;
 375         struct sha1_hash  sinit_hash;
 376         struct sha1_hash  mle_hash;
 377         struct sha1_hash  stm_hash;
 378         struct sha1_hash  lcp_policy_hash;
 379         u32               lcp_policy_control;
 380         u32               rlp_wakeup_addr;
 381         u32               reserved;
 382         u32               num_mdrs;
 383         u32               mdrs_off;
 384         u32               num_vtd_dmars;
 385         u32               vtd_dmars_off;
 386 } __packed;
 387
 388 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
 389 {
 390         void *heap_base, *heap_ptr, *config;
 391
 392         if (!tboot_enabled())
 393                 return dmar_tbl;
 394
 395         /*
 396          * ACPI tables may not be DMA protected by tboot, so use DMAR copy
 397          * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
 398          */
 399
 400         /* map config space in order to get heap addr */
 401         config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
 402                          PAGE_SIZE);
 403         if (!config)
 404                 return NULL;
 405
 406         /* now map TXT heap */
 407         heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
 408                             *(u64 *)(config + TXTCR_HEAP_SIZE));
 409         iounmap(config);
 410         if (!heap_base)
 411                 return NULL;
 412
 413         /* walk heap to SinitMleData */
 414         /* skip BiosData */
 415         heap_ptr = heap_base + *(u64 *)heap_base;
 416         /* skip OsMleData */
 417         heap_ptr += *(u64 *)heap_ptr;
 418         /* skip OsSinitData */
 419         heap_ptr += *(u64 *)heap_ptr;
 420         /* now points to SinitMleDataSize; set to SinitMleData */
 421         heap_ptr += sizeof(u64);
 422         /* get addr of DMAR table */
 423         dmar_tbl = (struct acpi_table_header *)(heap_ptr +
 424                    ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
 425                    sizeof(u64));
 426
 427         /* don't unmap heap because dmar.c needs access to this */
 428
 429         return dmar_tbl;
 430 }
 431
 432 int tboot_force_iommu(void)
 433 {
 434         if (!tboot_enabled())
 435                 return 0;
 436
 437         if (no_iommu || swiotlb || dmar_disabled)
 438                 pr_warning("Forcing Intel-IOMMU to enabled\n");
 439
 440         dmar_disabled = 0;
 441 #ifdef CONFIG_SWIOTLB
 442         swiotlb = 0;
 443 #endif
 444         no_iommu = 0;
 445
 446         return 1;
 447 }