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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/sched.h>
  26 #include <linux/init.h>
  27 #include <linux/dmar.h>
  28 #include <linux/pfn.h>
  29 #include <linux/mm.h>
  30
  31 #include <asm/trampoline.h>
  32 #include <asm/processor.h>
  33 #include <asm/bootparam.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/pgalloc.h>
  36 #include <asm/fixmap.h>
  37 #include <asm/proto.h>
  38 #include <asm/setup.h>
  39 #include <asm/tboot.h>
  40 #include <asm/e820.h>
  41 #include <asm/io.h>
  42
  43 #include "acpi/realmode/wakeup.h"
  44
  45 /* Global pointer to shared data; NULL means no measured launch. */
  46 struct tboot *tboot __read_mostly;
  47
  48 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
  49 #define AP_WAIT_TIMEOUT         1
  50
  51 #undef pr_fmt
  52 #define pr_fmt(fmt)     "tboot: " fmt
  53
  54 static u8 tboot_uuid[16] __initdata = TBOOT_UUID;
  55
  56 void __init tboot_probe(void)
  57 {
  58         /* Look for valid page-aligned address for shared page. */
  59         if (!boot_params.tboot_addr)
  60                 return;
  61         /*
  62          * also verify that it is mapped as we expect it before calling
  63          * set_fixmap(), to reduce chance of garbage value causing crash
  64          */
  65         if (!e820_any_mapped(boot_params.tboot_addr,
  66                              boot_params.tboot_addr, E820_RESERVED)) {
  67                 pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n");
  68                 return;
  69         }
  70
  71         /* only a natively booted kernel should be using TXT */
  72         if (paravirt_enabled()) {
  73                 pr_warning("non-0 tboot_addr but pv_ops is enabled\n");
  74                 return;
  75         }
  76
  77         /* Map and check for tboot UUID. */
  78         set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
  79         tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE);
  80         if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
  81                 pr_warning("tboot at 0x%llx is invalid\n",
  82                            boot_params.tboot_addr);
  83                 tboot = NULL;
  84                 return;
  85         }
  86         if (tboot->version < 5) {
  87                 pr_warning("tboot version is invalid: %u\n", tboot->version);
  88                 tboot = NULL;
  89                 return;
  90         }
  91
  92         pr_info("found shared page at phys addr 0x%llx:\n",
  93                 boot_params.tboot_addr);
  94         pr_debug("version: %d\n", tboot->version);
  95         pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
  96         pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
  97         pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
  98         pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
  99 }
 100
 101 static pgd_t *tboot_pg_dir;
 102 static struct mm_struct tboot_mm = {
 103         .mm_rb          = RB_ROOT,
 104         .pgd            = swapper_pg_dir,
 105         .mm_users       = ATOMIC_INIT(2),
 106         .mm_count       = ATOMIC_INIT(1),
 107         .mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
 108         .page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
 109         .mmlist         = LIST_HEAD_INIT(init_mm.mmlist),
 110         .cpu_vm_mask    = CPU_MASK_ALL,
 111 };
 112
 113 static inline void switch_to_tboot_pt(void)
 114 {
 115         write_cr3(virt_to_phys(tboot_pg_dir));
 116 }
 117
 118 static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
 119                           pgprot_t prot)
 120 {
 121         pgd_t *pgd;
 122         pud_t *pud;
 123         pmd_t *pmd;
 124         pte_t *pte;
 125
 126         pgd = pgd_offset(&tboot_mm, vaddr);
 127         pud = pud_alloc(&tboot_mm, pgd, vaddr);
 128         if (!pud)
 129                 return -1;
 130         pmd = pmd_alloc(&tboot_mm, pud, vaddr);
 131         if (!pmd)
 132                 return -1;
 133         pte = pte_alloc_map(&tboot_mm, pmd, vaddr);
 134         if (!pte)
 135                 return -1;
 136         set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
 137         pte_unmap(pte);
 138         return 0;
 139 }
 140
 141 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
 142                            unsigned long nr)
 143 {
 144         /* Reuse the original kernel mapping */
 145         tboot_pg_dir = pgd_alloc(&tboot_mm);
 146         if (!tboot_pg_dir)
 147                 return -1;
 148
 149         for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
 150                 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
 151                         return -1;
 152         }
 153
 154         return 0;
 155 }
 156
 157 void tboot_create_trampoline(void)
 158 {
 159         u32 map_base, map_size;
 160
 161         if (!tboot_enabled())
 162                 return;
 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         /* AP trampoline code */
 193         add_mac_region(virt_to_phys(trampoline_base), TRAMPOLINE_SIZE);
 194         /* kernel code + data + bss */
 195         add_mac_region(virt_to_phys(_text), _end - _text);
 196
 197         tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
 198
 199         return 0;
 200 }
 201
 202 #else /* no CONFIG_ACPI_SLEEP */
 203
 204 static int tboot_setup_sleep(void)
 205 {
 206         /* S3 shutdown requested, but S3 not supported by the kernel... */
 207         BUG();
 208         return -1;
 209 }
 210
 211 #endif
 212
 213 void tboot_shutdown(u32 shutdown_type)
 214 {
 215         void (*shutdown)(void);
 216
 217         if (!tboot_enabled())
 218                 return;
 219
 220         /*
 221          * if we're being called before the 1:1 mapping is set up then just
 222          * return and let the normal shutdown happen; this should only be
 223          * due to very early panic()
 224          */
 225         if (!tboot_pg_dir)
 226                 return;
 227
 228         /* if this is S3 then set regions to MAC */
 229         if (shutdown_type == TB_SHUTDOWN_S3)
 230                 if (tboot_setup_sleep())
 231                         return;
 232
 233         tboot->shutdown_type = shutdown_type;
 234
 235         switch_to_tboot_pt();
 236
 237         shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
 238         shutdown();
 239
 240         /* should not reach here */
 241         while (1)
 242                 halt();
 243 }
 244
 245 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
 246 {
 247 #define TB_COPY_GAS(tbg, g)                     \
 248         tbg.space_id     = g.space_id;          \
 249         tbg.bit_width    = g.bit_width;         \
 250         tbg.bit_offset   = g.bit_offset;        \
 251         tbg.access_width = g.access_width;      \
 252         tbg.address      = g.address;
 253
 254         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
 255         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
 256         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
 257         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);
 258
 259         /*
 260          * We need phys addr of waking vector, but can't use virt_to_phys() on
 261          * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
 262          * addr.
 263          */
 264         tboot->acpi_sinfo.wakeup_vector = fadt->facs +
 265                 offsetof(struct acpi_table_facs, firmware_waking_vector);
 266 }
 267
 268 void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
 269 {
 270         static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
 271                 /* S0,1,2: */ -1, -1, -1,
 272                 /* S3: */ TB_SHUTDOWN_S3,
 273                 /* S4: */ TB_SHUTDOWN_S4,
 274                 /* S5: */ TB_SHUTDOWN_S5 };
 275
 276         if (!tboot_enabled())
 277                 return;
 278
 279         tboot_copy_fadt(&acpi_gbl_FADT);
 280         tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
 281         tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
 282         /* we always use the 32b wakeup vector */
 283         tboot->acpi_sinfo.vector_width = 32;
 284
 285         if (sleep_state >= ACPI_S_STATE_COUNT ||
 286             acpi_shutdown_map[sleep_state] == -1) {
 287                 pr_warning("unsupported sleep state 0x%x\n", sleep_state);
 288                 return;
 289         }
 290
 291         tboot_shutdown(acpi_shutdown_map[sleep_state]);
 292 }
 293
 294 int tboot_wait_for_aps(int num_aps)
 295 {
 296         unsigned long timeout;
 297
 298         if (!tboot_enabled())
 299                 return 0;
 300
 301         timeout = jiffies + AP_WAIT_TIMEOUT*HZ;
 302         while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
 303                time_before(jiffies, timeout))
 304                 cpu_relax();
 305
 306         return time_before(jiffies, timeout) ? 0 : 1;
 307 }
 308
 309 /*
 310  * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
 311  */
 312
 313 #define TXT_PUB_CONFIG_REGS_BASE       0xfed30000
 314 #define TXT_PRIV_CONFIG_REGS_BASE      0xfed20000
 315
 316 /* # pages for each config regs space - used by fixmap */
 317 #define NR_TXT_CONFIG_PAGES     ((TXT_PUB_CONFIG_REGS_BASE -                \
 318                                   TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
 319
 320 /* offsets from pub/priv config space */
 321 #define TXTCR_HEAP_BASE             0x0300
 322 #define TXTCR_HEAP_SIZE             0x0308
 323
 324 #define SHA1_SIZE      20
 325
 326 struct sha1_hash {
 327         u8 hash[SHA1_SIZE];
 328 };
 329
 330 struct sinit_mle_data {
 331         u32               version;             /* currently 6 */
 332         struct sha1_hash  bios_acm_id;
 333         u32               edx_senter_flags;
 334         u64               mseg_valid;
 335         struct sha1_hash  sinit_hash;
 336         struct sha1_hash  mle_hash;
 337         struct sha1_hash  stm_hash;
 338         struct sha1_hash  lcp_policy_hash;
 339         u32               lcp_policy_control;
 340         u32               rlp_wakeup_addr;
 341         u32               reserved;
 342         u32               num_mdrs;
 343         u32               mdrs_off;
 344         u32               num_vtd_dmars;
 345         u32               vtd_dmars_off;
 346 } __packed;
 347
 348 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
 349 {
 350         void *heap_base, *heap_ptr, *config;
 351
 352         if (!tboot_enabled())
 353                 return dmar_tbl;
 354
 355         /*
 356          * ACPI tables may not be DMA protected by tboot, so use DMAR copy
 357          * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
 358          */
 359
 360         /* map config space in order to get heap addr */
 361         config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
 362                          PAGE_SIZE);
 363         if (!config)
 364                 return NULL;
 365
 366         /* now map TXT heap */
 367         heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
 368                             *(u64 *)(config + TXTCR_HEAP_SIZE));
 369         iounmap(config);
 370         if (!heap_base)
 371                 return NULL;
 372
 373         /* walk heap to SinitMleData */
 374         /* skip BiosData */
 375         heap_ptr = heap_base + *(u64 *)heap_base;
 376         /* skip OsMleData */
 377         heap_ptr += *(u64 *)heap_ptr;
 378         /* skip OsSinitData */
 379         heap_ptr += *(u64 *)heap_ptr;
 380         /* now points to SinitMleDataSize; set to SinitMleData */
 381         heap_ptr += sizeof(u64);
 382         /* get addr of DMAR table */
 383         dmar_tbl = (struct acpi_table_header *)(heap_ptr +
 384                    ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
 385                    sizeof(u64));
 386
 387         /* don't unmap heap because dmar.c needs access to this */
 388
 389         return dmar_tbl;
 390 }
 391
 392 int tboot_force_iommu(void)
 393 {
 394         if (!tboot_enabled())
 395                 return 0;
 396
 397         if (no_iommu || swiotlb || dmar_disabled)
 398                 pr_warning("Forcing Intel-IOMMU to enabled\n");
 399
 400         dmar_disabled = 0;
 401 #ifdef CONFIG_SWIOTLB
 402         swiotlb = 0;
 403 #endif
 404         no_iommu = 0;
 405
 406         return 1;
 407 }