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/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/setup.h>
  37 #include <asm/tboot.h>
  38 #include <asm/e820.h>
  39 #include <asm/io.h>
  40
  41 #include "acpi/realmode/wakeup.h"
  42
  43 /* Global pointer to shared data; NULL means no measured launch. */
  44 struct tboot *tboot __read_mostly;
  45
  46 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
  47 #define AP_WAIT_TIMEOUT         1
  48
  49 #undef pr_fmt
  50 #define pr_fmt(fmt)     "tboot: " fmt
  51
  52 static u8 tboot_uuid[16] __initdata = TBOOT_UUID;
  53
  54 void __init tboot_probe(void)
  55 {
  56         /* Look for valid page-aligned address for shared page. */
  57         if (!boot_params.tboot_addr)
  58                 return;
  59         /*
  60          * also verify that it is mapped as we expect it before calling
  61          * set_fixmap(), to reduce chance of garbage value causing crash
  62          */
  63         if (!e820_any_mapped(boot_params.tboot_addr,
  64                              boot_params.tboot_addr, E820_RESERVED)) {
  65                 pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n");
  66                 return;
  67         }
  68
  69         /* only a natively booted kernel should be using TXT */
  70         if (paravirt_enabled()) {
  71                 pr_warning("non-0 tboot_addr but pv_ops is enabled\n");
  72                 return;
  73         }
  74
  75         /* Map and check for tboot UUID. */
  76         set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
  77         tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE);
  78         if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
  79                 pr_warning("tboot at 0x%llx is invalid\n",
  80                            boot_params.tboot_addr);
  81                 tboot = NULL;
  82                 return;
  83         }
  84         if (tboot->version < 5) {
  85                 pr_warning("tboot version is invalid: %u\n", tboot->version);
  86                 tboot = NULL;
  87                 return;
  88         }
  89
  90         pr_info("found shared page at phys addr 0x%llx:\n",
  91                 boot_params.tboot_addr);
  92         pr_debug("version: %d\n", tboot->version);
  93         pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
  94         pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
  95         pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
  96         pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
  97 }
  98
  99 static pgd_t *tboot_pg_dir;
 100 static struct mm_struct tboot_mm = {
 101         .mm_rb          = RB_ROOT,
 102         .pgd            = swapper_pg_dir,
 103         .mm_users       = ATOMIC_INIT(2),
 104         .mm_count       = ATOMIC_INIT(1),
 105         .mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
 106         .page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
 107         .mmlist         = LIST_HEAD_INIT(init_mm.mmlist),
 108         .cpu_vm_mask    = CPU_MASK_ALL,
 109 };
 110
 111 static inline void switch_to_tboot_pt(void)
 112 {
 113         write_cr3(virt_to_phys(tboot_pg_dir));
 114 }
 115
 116 static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
 117                           pgprot_t prot)
 118 {
 119         pgd_t *pgd;
 120         pud_t *pud;
 121         pmd_t *pmd;
 122         pte_t *pte;
 123
 124         pgd = pgd_offset(&tboot_mm, vaddr);
 125         pud = pud_alloc(&tboot_mm, pgd, vaddr);
 126         if (!pud)
 127                 return -1;
 128         pmd = pmd_alloc(&tboot_mm, pud, vaddr);
 129         if (!pmd)
 130                 return -1;
 131         pte = pte_alloc_map(&tboot_mm, pmd, vaddr);
 132         if (!pte)
 133                 return -1;
 134         set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
 135         pte_unmap(pte);
 136         return 0;
 137 }
 138
 139 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
 140                            unsigned long nr)
 141 {
 142         /* Reuse the original kernel mapping */
 143         tboot_pg_dir = pgd_alloc(&tboot_mm);
 144         if (!tboot_pg_dir)
 145                 return -1;
 146
 147         for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
 148                 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
 149                         return -1;
 150         }
 151
 152         return 0;
 153 }
 154
 155 void tboot_create_trampoline(void)
 156 {
 157         u32 map_base, map_size;
 158
 159         if (!tboot_enabled())
 160                 return;
 161
 162         /* Create identity map for tboot shutdown code. */
 163         map_base = PFN_DOWN(tboot->tboot_base);
 164         map_size = PFN_UP(tboot->tboot_size);
 165         if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size))
 166                 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", map_base, map_size);
 167 }
 168
 169 static void set_mac_regions(void)
 170 {
 171         tboot->num_mac_regions = 3;
 172         /* S3 resume code */
 173         tboot->mac_regions[0].start = PFN_PHYS(PFN_DOWN(acpi_wakeup_address));
 174         tboot->mac_regions[0].size = PFN_UP(WAKEUP_SIZE) << PAGE_SHIFT;
 175         /* AP trampoline code */
 176         tboot->mac_regions[1].start =
 177                         PFN_PHYS(PFN_DOWN(virt_to_phys(trampoline_base)));
 178         tboot->mac_regions[1].size = PFN_UP(TRAMPOLINE_SIZE) << PAGE_SHIFT;
 179         /* kernel code + data + bss */
 180         tboot->mac_regions[2].start = PFN_PHYS(PFN_DOWN(virt_to_phys(&_text)));
 181         tboot->mac_regions[2].size = PFN_PHYS(PFN_UP(virt_to_phys(&_end))) -
 182                                      PFN_PHYS(PFN_DOWN(virt_to_phys(&_text)));
 183 }
 184
 185 void tboot_shutdown(u32 shutdown_type)
 186 {
 187         void (*shutdown)(void);
 188
 189         if (!tboot_enabled())
 190                 return;
 191
 192         /*
 193          * if we're being called before the 1:1 mapping is set up then just
 194          * return and let the normal shutdown happen; this should only be
 195          * due to very early panic()
 196          */
 197         if (!tboot_pg_dir)
 198                 return;
 199
 200         /* if this is S3 then set regions to MAC */
 201         if (shutdown_type == TB_SHUTDOWN_S3)
 202                 set_mac_regions();
 203
 204         tboot->shutdown_type = shutdown_type;
 205
 206         switch_to_tboot_pt();
 207
 208         shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
 209         shutdown();
 210
 211         /* should not reach here */
 212         while (1)
 213                 halt();
 214 }
 215
 216 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
 217 {
 218 #define TB_COPY_GAS(tbg, g)                     \
 219         tbg.space_id     = g.space_id;          \
 220         tbg.bit_width    = g.bit_width;         \
 221         tbg.bit_offset   = g.bit_offset;        \
 222         tbg.access_width = g.access_width;      \
 223         tbg.address      = g.address;
 224
 225         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
 226         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
 227         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
 228         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);
 229
 230         /*
 231          * We need phys addr of waking vector, but can't use virt_to_phys() on
 232          * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
 233          * addr.
 234          */
 235         tboot->acpi_sinfo.wakeup_vector = fadt->facs +
 236                 offsetof(struct acpi_table_facs, firmware_waking_vector);
 237 }
 238
 239 void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
 240 {
 241         static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
 242                 /* S0,1,2: */ -1, -1, -1,
 243                 /* S3: */ TB_SHUTDOWN_S3,
 244                 /* S4: */ TB_SHUTDOWN_S4,
 245                 /* S5: */ TB_SHUTDOWN_S5 };
 246
 247         if (!tboot_enabled())
 248                 return;
 249
 250         tboot_copy_fadt(&acpi_gbl_FADT);
 251         tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
 252         tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
 253         /* we always use the 32b wakeup vector */
 254         tboot->acpi_sinfo.vector_width = 32;
 255         tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
 256
 257         if (sleep_state >= ACPI_S_STATE_COUNT ||
 258             acpi_shutdown_map[sleep_state] == -1) {
 259                 pr_warning("unsupported sleep state 0x%x\n", sleep_state);
 260                 return;
 261         }
 262
 263         tboot_shutdown(acpi_shutdown_map[sleep_state]);
 264 }
 265
 266 int tboot_wait_for_aps(int num_aps)
 267 {
 268         unsigned long timeout;
 269
 270         if (!tboot_enabled())
 271                 return 0;
 272
 273         timeout = jiffies + AP_WAIT_TIMEOUT*HZ;
 274         while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
 275                time_before(jiffies, timeout))
 276                 cpu_relax();
 277
 278         return time_before(jiffies, timeout) ? 0 : 1;
 279 }
 280
 281 /*
 282  * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
 283  */
 284
 285 #define TXT_PUB_CONFIG_REGS_BASE       0xfed30000
 286 #define TXT_PRIV_CONFIG_REGS_BASE      0xfed20000
 287
 288 /* # pages for each config regs space - used by fixmap */
 289 #define NR_TXT_CONFIG_PAGES     ((TXT_PUB_CONFIG_REGS_BASE -                \
 290                                   TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
 291
 292 /* offsets from pub/priv config space */
 293 #define TXTCR_HEAP_BASE             0x0300
 294 #define TXTCR_HEAP_SIZE             0x0308
 295
 296 #define SHA1_SIZE      20
 297
 298 struct sha1_hash {
 299         u8 hash[SHA1_SIZE];
 300 };
 301
 302 struct sinit_mle_data {
 303         u32               version;             /* currently 6 */
 304         struct sha1_hash  bios_acm_id;
 305         u32               edx_senter_flags;
 306         u64               mseg_valid;
 307         struct sha1_hash  sinit_hash;
 308         struct sha1_hash  mle_hash;
 309         struct sha1_hash  stm_hash;
 310         struct sha1_hash  lcp_policy_hash;
 311         u32               lcp_policy_control;
 312         u32               rlp_wakeup_addr;
 313         u32               reserved;
 314         u32               num_mdrs;
 315         u32               mdrs_off;
 316         u32               num_vtd_dmars;
 317         u32               vtd_dmars_off;
 318 } __packed;
 319
 320 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
 321 {
 322         void *heap_base, *heap_ptr, *config;
 323
 324         if (!tboot_enabled())
 325                 return dmar_tbl;
 326
 327         /*
 328          * ACPI tables may not be DMA protected by tboot, so use DMAR copy
 329          * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
 330          */
 331
 332         /* map config space in order to get heap addr */
 333         config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
 334                          PAGE_SIZE);
 335         if (!config)
 336                 return NULL;
 337
 338         /* now map TXT heap */
 339         heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
 340                             *(u64 *)(config + TXTCR_HEAP_SIZE));
 341         iounmap(config);
 342         if (!heap_base)
 343                 return NULL;
 344
 345         /* walk heap to SinitMleData */
 346         /* skip BiosData */
 347         heap_ptr = heap_base + *(u64 *)heap_base;
 348         /* skip OsMleData */
 349         heap_ptr += *(u64 *)heap_ptr;
 350         /* skip OsSinitData */
 351         heap_ptr += *(u64 *)heap_ptr;
 352         /* now points to SinitMleDataSize; set to SinitMleData */
 353         heap_ptr += sizeof(u64);
 354         /* get addr of DMAR table */
 355         dmar_tbl = (struct acpi_table_header *)(heap_ptr +
 356                    ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
 357                    sizeof(u64));
 358
 359         /* don't unmap heap because dmar.c needs access to this */
 360
 361         return dmar_tbl;
 362 }
 363
 364 int tboot_force_iommu(void)
 365 {
 366         if (!tboot_enabled())
 367                 return 0;
 368
 369         if (no_iommu || swiotlb || dmar_disabled)
 370                 pr_warning("Forcing Intel-IOMMU to enabled\n");
 371
 372         dmar_disabled = 0;
 373 #ifdef CONFIG_SWIOTLB
 374         swiotlb = 0;
 375 #endif
 376         no_iommu = 0;
 377
 378         return 1;
 379 }