drivers/iommu/dmar.c

   1 /*
   2  * Copyright (c) 2006, Intel Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Copyright (C) 2006-2008 Intel Corporation
  18  * Author: Ashok Raj <ashok.raj@intel.com>
  19  * Author: Shaohua Li <shaohua.li@intel.com>
  20  * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
  21  *
  22  * This file implements early detection/parsing of Remapping Devices
  23  * reported to OS through BIOS via DMA remapping reporting (DMAR) ACPI
  24  * tables.
  25  *
  26  * These routines are used by both DMA-remapping and Interrupt-remapping
  27  */
  28
  29 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt /* has to precede printk.h */
  30
  31 #include <linux/pci.h>
  32 #include <linux/dmar.h>
  33 #include <linux/iova.h>
  34 #include <linux/intel-iommu.h>
  35 #include <linux/timer.h>
  36 #include <linux/irq.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/tboot.h>
  39 #include <linux/dmi.h>
  40 #include <linux/slab.h>
  41 #include <asm/irq_remapping.h>
  42 #include <asm/iommu_table.h>
  43
  44 #include "irq_remapping.h"
  45
  46 /* No locks are needed as DMA remapping hardware unit
  47  * list is constructed at boot time and hotplug of
  48  * these units are not supported by the architecture.
  49  */
  50 LIST_HEAD(dmar_drhd_units);
  51
  52 struct acpi_table_header * __initdata dmar_tbl;
  53 static acpi_size dmar_tbl_size;
  54
  55 static void __init dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
  56 {
  57         /*
  58          * add INCLUDE_ALL at the tail, so scan the list will find it at
  59          * the very end.
  60          */
  61         if (drhd->include_all)
  62                 list_add_tail(&drhd->list, &dmar_drhd_units);
  63         else
  64                 list_add(&drhd->list, &dmar_drhd_units);
  65 }
  66
  67 static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
  68                                            struct pci_dev **dev, u16 segment)
  69 {
  70         struct pci_bus *bus;
  71         struct pci_dev *pdev = NULL;
  72         struct acpi_dmar_pci_path *path;
  73         int count;
  74
  75         bus = pci_find_bus(segment, scope->bus);
  76         path = (struct acpi_dmar_pci_path *)(scope + 1);
  77         count = (scope->length - sizeof(struct acpi_dmar_device_scope))
  78                 / sizeof(struct acpi_dmar_pci_path);
  79
  80         while (count) {
  81                 if (pdev)
  82                         pci_dev_put(pdev);
  83                 /*
  84                  * Some BIOSes list non-exist devices in DMAR table, just
  85                  * ignore it
  86                  */
  87                 if (!bus) {
  88                         pr_warn("Device scope bus [%d] not found\n", scope->bus);
  89                         break;
  90                 }
  91                 pdev = pci_get_slot(bus, PCI_DEVFN(path->dev, path->fn));
  92                 if (!pdev) {
  93                         /* warning will be printed below */
  94                         break;
  95                 }
  96                 path ++;
  97                 count --;
  98                 bus = pdev->subordinate;
  99         }
 100         if (!pdev) {
 101                 pr_warn("Device scope device [%04x:%02x:%02x.%02x] not found\n",
 102                         segment, scope->bus, path->dev, path->fn);
 103                 *dev = NULL;
 104                 return 0;
 105         }
 106         if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT && \
 107                         pdev->subordinate) || (scope->entry_type == \
 108                         ACPI_DMAR_SCOPE_TYPE_BRIDGE && !pdev->subordinate)) {
 109                 pci_dev_put(pdev);
 110                 pr_warn("Device scope type does not match for %s\n",
 111                         pci_name(pdev));
 112                 return -EINVAL;
 113         }
 114         *dev = pdev;
 115         return 0;
 116 }
 117
 118 int __init dmar_parse_dev_scope(void *start, void *end, int *cnt,
 119                                 struct pci_dev ***devices, u16 segment)
 120 {
 121         struct acpi_dmar_device_scope *scope;
 122         void * tmp = start;
 123         int index;
 124         int ret;
 125
 126         *cnt = 0;
 127         while (start < end) {
 128                 scope = start;
 129                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
 130                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE)
 131                         (*cnt)++;
 132                 else if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_IOAPIC &&
 133                         scope->entry_type != ACPI_DMAR_SCOPE_TYPE_HPET) {
 134                         pr_warn("Unsupported device scope\n");
 135                 }
 136                 start += scope->length;
 137         }
 138         if (*cnt == 0)
 139                 return 0;
 140
 141         *devices = kcalloc(*cnt, sizeof(struct pci_dev *), GFP_KERNEL);
 142         if (!*devices)
 143                 return -ENOMEM;
 144
 145         start = tmp;
 146         index = 0;
 147         while (start < end) {
 148                 scope = start;
 149                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
 150                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE) {
 151                         ret = dmar_parse_one_dev_scope(scope,
 152                                 &(*devices)[index], segment);
 153                         if (ret) {
 154                                 kfree(*devices);
 155                                 return ret;
 156                         }
 157                         index ++;
 158                 }
 159                 start += scope->length;
 160         }
 161
 162         return 0;
 163 }
 164
 165 /**
 166  * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition
 167  * structure which uniquely represent one DMA remapping hardware unit
 168  * present in the platform
 169  */
 170 static int __init
 171 dmar_parse_one_drhd(struct acpi_dmar_header *header)
 172 {
 173         struct acpi_dmar_hardware_unit *drhd;
 174         struct dmar_drhd_unit *dmaru;
 175         int ret = 0;
 176
 177         drhd = (struct acpi_dmar_hardware_unit *)header;
 178         dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL);
 179         if (!dmaru)
 180                 return -ENOMEM;
 181
 182         dmaru->hdr = header;
 183         dmaru->reg_base_addr = drhd->address;
 184         dmaru->segment = drhd->segment;
 185         dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */
 186
 187         ret = alloc_iommu(dmaru);
 188         if (ret) {
 189                 kfree(dmaru);
 190                 return ret;
 191         }
 192         dmar_register_drhd_unit(dmaru);
 193         return 0;
 194 }
 195
 196 static int __init dmar_parse_dev(struct dmar_drhd_unit *dmaru)
 197 {
 198         struct acpi_dmar_hardware_unit *drhd;
 199         int ret = 0;
 200
 201         drhd = (struct acpi_dmar_hardware_unit *) dmaru->hdr;
 202
 203         if (dmaru->include_all)
 204                 return 0;
 205
 206         ret = dmar_parse_dev_scope((void *)(drhd + 1),
 207                                 ((void *)drhd) + drhd->header.length,
 208                                 &dmaru->devices_cnt, &dmaru->devices,
 209                                 drhd->segment);
 210         if (ret) {
 211                 list_del(&dmaru->list);
 212                 kfree(dmaru);
 213         }
 214         return ret;
 215 }
 216
 217 #ifdef CONFIG_ACPI_NUMA
 218 static int __init
 219 dmar_parse_one_rhsa(struct acpi_dmar_header *header)
 220 {
 221         struct acpi_dmar_rhsa *rhsa;
 222         struct dmar_drhd_unit *drhd;
 223
 224         rhsa = (struct acpi_dmar_rhsa *)header;
 225         for_each_drhd_unit(drhd) {
 226                 if (drhd->reg_base_addr == rhsa->base_address) {
 227                         int node = acpi_map_pxm_to_node(rhsa->proximity_domain);
 228
 229                         if (!node_online(node))
 230                                 node = -1;
 231                         drhd->iommu->node = node;
 232                         return 0;
 233                 }
 234         }
 235         WARN_TAINT(
 236                 1, TAINT_FIRMWARE_WORKAROUND,
 237                 "Your BIOS is broken; RHSA refers to non-existent DMAR unit at %llx\n"
 238                 "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
 239                 drhd->reg_base_addr,
 240                 dmi_get_system_info(DMI_BIOS_VENDOR),
 241                 dmi_get_system_info(DMI_BIOS_VERSION),
 242                 dmi_get_system_info(DMI_PRODUCT_VERSION));
 243
 244         return 0;
 245 }
 246 #endif
 247
 248 static void __init
 249 dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
 250 {
 251         struct acpi_dmar_hardware_unit *drhd;
 252         struct acpi_dmar_reserved_memory *rmrr;
 253         struct acpi_dmar_atsr *atsr;
 254         struct acpi_dmar_rhsa *rhsa;
 255
 256         switch (header->type) {
 257         case ACPI_DMAR_TYPE_HARDWARE_UNIT:
 258                 drhd = container_of(header, struct acpi_dmar_hardware_unit,
 259                                     header);
 260                 pr_info("DRHD base: %#016Lx flags: %#x\n",
 261                         (unsigned long long)drhd->address, drhd->flags);
 262                 break;
 263         case ACPI_DMAR_TYPE_RESERVED_MEMORY:
 264                 rmrr = container_of(header, struct acpi_dmar_reserved_memory,
 265                                     header);
 266                 pr_info("RMRR base: %#016Lx end: %#016Lx\n",
 267                         (unsigned long long)rmrr->base_address,
 268                         (unsigned long long)rmrr->end_address);
 269                 break;
 270         case ACPI_DMAR_TYPE_ATSR:
 271                 atsr = container_of(header, struct acpi_dmar_atsr, header);
 272                 pr_info("ATSR flags: %#x\n", atsr->flags);
 273                 break;
 274         case ACPI_DMAR_HARDWARE_AFFINITY:
 275                 rhsa = container_of(header, struct acpi_dmar_rhsa, header);
 276                 pr_info("RHSA base: %#016Lx proximity domain: %#x\n",
 277                        (unsigned long long)rhsa->base_address,
 278                        rhsa->proximity_domain);
 279                 break;
 280         }
 281 }
 282
 283 /**
 284  * dmar_table_detect - checks to see if the platform supports DMAR devices
 285  */
 286 static int __init dmar_table_detect(void)
 287 {
 288         acpi_status status = AE_OK;
 289
 290         /* if we could find DMAR table, then there are DMAR devices */
 291         status = acpi_get_table_with_size(ACPI_SIG_DMAR, 0,
 292                                 (struct acpi_table_header **)&dmar_tbl,
 293                                 &dmar_tbl_size);
 294
 295         if (ACPI_SUCCESS(status) && !dmar_tbl) {
 296                 pr_warn("Unable to map DMAR\n");
 297                 status = AE_NOT_FOUND;
 298         }
 299
 300         return (ACPI_SUCCESS(status) ? 1 : 0);
 301 }
 302
 303 /**
 304  * parse_dmar_table - parses the DMA reporting table
 305  */
 306 static int __init
 307 parse_dmar_table(void)
 308 {
 309         struct acpi_table_dmar *dmar;
 310         struct acpi_dmar_header *entry_header;
 311         int ret = 0;
 312         int drhd_count = 0;
 313
 314         /*
 315          * Do it again, earlier dmar_tbl mapping could be mapped with
 316          * fixed map.
 317          */
 318         dmar_table_detect();
 319
 320         /*
 321          * ACPI tables may not be DMA protected by tboot, so use DMAR copy
 322          * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
 323          */
 324         dmar_tbl = tboot_get_dmar_table(dmar_tbl);
 325
 326         dmar = (struct acpi_table_dmar *)dmar_tbl;
 327         if (!dmar)
 328                 return -ENODEV;
 329
 330         if (dmar->width < PAGE_SHIFT - 1) {
 331                 pr_warn("Invalid DMAR haw\n");
 332                 return -EINVAL;
 333         }
 334
 335         pr_info("Host address width %d\n", dmar->width + 1);
 336
 337         entry_header = (struct acpi_dmar_header *)(dmar + 1);
 338         while (((unsigned long)entry_header) <
 339                         (((unsigned long)dmar) + dmar_tbl->length)) {
 340                 /* Avoid looping forever on bad ACPI tables */
 341                 if (entry_header->length == 0) {
 342                         pr_warn("Invalid 0-length structure\n");
 343                         ret = -EINVAL;
 344                         break;
 345                 }
 346
 347                 dmar_table_print_dmar_entry(entry_header);
 348
 349                 switch (entry_header->type) {
 350                 case ACPI_DMAR_TYPE_HARDWARE_UNIT:
 351                         drhd_count++;
 352                         ret = dmar_parse_one_drhd(entry_header);
 353                         break;
 354                 case ACPI_DMAR_TYPE_RESERVED_MEMORY:
 355                         ret = dmar_parse_one_rmrr(entry_header);
 356                         break;
 357                 case ACPI_DMAR_TYPE_ATSR:
 358                         ret = dmar_parse_one_atsr(entry_header);
 359                         break;
 360                 case ACPI_DMAR_HARDWARE_AFFINITY:
 361 #ifdef CONFIG_ACPI_NUMA
 362                         ret = dmar_parse_one_rhsa(entry_header);
 363 #endif
 364                         break;
 365                 default:
 366                         pr_warn("Unknown DMAR structure type %d\n",
 367                                 entry_header->type);
 368                         ret = 0; /* for forward compatibility */
 369                         break;
 370                 }
 371                 if (ret)
 372                         break;
 373
 374                 entry_header = ((void *)entry_header + entry_header->length);
 375         }
 376         if (drhd_count == 0)
 377                 pr_warn(FW_BUG "No DRHD structure found in DMAR table\n");
 378         return ret;
 379 }
 380
 381 static int dmar_pci_device_match(struct pci_dev *devices[], int cnt,
 382                           struct pci_dev *dev)
 383 {
 384         int index;
 385
 386         while (dev) {
 387                 for (index = 0; index < cnt; index++)
 388                         if (dev == devices[index])
 389                                 return 1;
 390
 391                 /* Check our parent */
 392                 dev = dev->bus->self;
 393         }
 394
 395         return 0;
 396 }
 397
 398 struct dmar_drhd_unit *
 399 dmar_find_matched_drhd_unit(struct pci_dev *dev)
 400 {
 401         struct dmar_drhd_unit *dmaru = NULL;
 402         struct acpi_dmar_hardware_unit *drhd;
 403
 404         dev = pci_physfn(dev);
 405
 406         list_for_each_entry(dmaru, &dmar_drhd_units, list) {
 407                 drhd = container_of(dmaru->hdr,
 408                                     struct acpi_dmar_hardware_unit,
 409                                     header);
 410
 411                 if (dmaru->include_all &&
 412                     drhd->segment == pci_domain_nr(dev->bus))
 413                         return dmaru;
 414
 415                 if (dmar_pci_device_match(dmaru->devices,
 416                                           dmaru->devices_cnt, dev))
 417                         return dmaru;
 418         }
 419
 420         return NULL;
 421 }
 422
 423 int __init dmar_dev_scope_init(void)
 424 {
 425         static int dmar_dev_scope_initialized;
 426         struct dmar_drhd_unit *drhd, *drhd_n;
 427         int ret = -ENODEV;
 428
 429         if (dmar_dev_scope_initialized)
 430                 return dmar_dev_scope_initialized;
 431
 432         if (list_empty(&dmar_drhd_units))
 433                 goto fail;
 434
 435         list_for_each_entry_safe(drhd, drhd_n, &dmar_drhd_units, list) {
 436                 ret = dmar_parse_dev(drhd);
 437                 if (ret)
 438                         goto fail;
 439         }
 440
 441         ret = dmar_parse_rmrr_atsr_dev();
 442         if (ret)
 443                 goto fail;
 444
 445         dmar_dev_scope_initialized = 1;
 446         return 0;
 447
 448 fail:
 449         dmar_dev_scope_initialized = ret;
 450         return ret;
 451 }
 452
 453
 454 int __init dmar_table_init(void)
 455 {
 456         static int dmar_table_initialized;
 457         int ret;
 458
 459         if (dmar_table_initialized)
 460                 return 0;
 461
 462         dmar_table_initialized = 1;
 463
 464         ret = parse_dmar_table();
 465         if (ret) {
 466                 if (ret != -ENODEV)
 467                         pr_info("parse DMAR table failure.\n");
 468                 return ret;
 469         }
 470
 471         if (list_empty(&dmar_drhd_units)) {
 472                 pr_info("No DMAR devices found\n");
 473                 return -ENODEV;
 474         }
 475
 476         return 0;
 477 }
 478
 479 static void warn_invalid_dmar(u64 addr, const char *message)
 480 {
 481         WARN_TAINT_ONCE(
 482                 1, TAINT_FIRMWARE_WORKAROUND,
 483                 "Your BIOS is broken; DMAR reported at address %llx%s!\n"
 484                 "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
 485                 addr, message,
 486                 dmi_get_system_info(DMI_BIOS_VENDOR),
 487                 dmi_get_system_info(DMI_BIOS_VERSION),
 488                 dmi_get_system_info(DMI_PRODUCT_VERSION));
 489 }
 490
 491 int __init check_zero_address(void)
 492 {
 493         struct acpi_table_dmar *dmar;
 494         struct acpi_dmar_header *entry_header;
 495         struct acpi_dmar_hardware_unit *drhd;
 496
 497         dmar = (struct acpi_table_dmar *)dmar_tbl;
 498         entry_header = (struct acpi_dmar_header *)(dmar + 1);
 499
 500         while (((unsigned long)entry_header) <
 501                         (((unsigned long)dmar) + dmar_tbl->length)) {
 502                 /* Avoid looping forever on bad ACPI tables */
 503                 if (entry_header->length == 0) {
 504                         pr_warn("Invalid 0-length structure\n");
 505                         return 0;
 506                 }
 507
 508                 if (entry_header->type == ACPI_DMAR_TYPE_HARDWARE_UNIT) {
 509                         void __iomem *addr;
 510                         u64 cap, ecap;
 511
 512                         drhd = (void *)entry_header;
 513                         if (!drhd->address) {
 514                                 warn_invalid_dmar(0, "");
 515                                 goto failed;
 516                         }
 517
 518                         addr = early_ioremap(drhd->address, VTD_PAGE_SIZE);
 519                         if (!addr ) {
 520                                 printk("IOMMU: can't validate: %llx\n", drhd->address);
 521                                 goto failed;
 522                         }
 523                         cap = dmar_readq(addr + DMAR_CAP_REG);
 524                         ecap = dmar_readq(addr + DMAR_ECAP_REG);
 525                         early_iounmap(addr, VTD_PAGE_SIZE);
 526                         if (cap == (uint64_t)-1 && ecap == (uint64_t)-1) {
 527                                 warn_invalid_dmar(drhd->address,
 528                                                   " returns all ones");
 529                                 goto failed;
 530                         }
 531                 }
 532
 533                 entry_header = ((void *)entry_header + entry_header->length);
 534         }
 535         return 1;
 536
 537 failed:
 538         return 0;
 539 }
 540
 541 int __init detect_intel_iommu(void)
 542 {
 543         int ret;
 544
 545         ret = dmar_table_detect();
 546         if (ret)
 547                 ret = check_zero_address();
 548         {
 549                 struct acpi_table_dmar *dmar;
 550
 551                 dmar = (struct acpi_table_dmar *) dmar_tbl;
 552
 553                 if (ret && irq_remapping_enabled && cpu_has_x2apic &&
 554                     dmar->flags & 0x1)
 555                         pr_info("Queued invalidation will be enabled to support x2apic and Intr-remapping.\n");
 556
 557                 if (ret && !no_iommu && !iommu_detected && !dmar_disabled) {
 558                         iommu_detected = 1;
 559                         /* Make sure ACS will be enabled */
 560                         pci_request_acs();
 561                 }
 562
 563 #ifdef CONFIG_X86
 564                 if (ret)
 565                         x86_init.iommu.iommu_init = intel_iommu_init;
 566 #endif
 567         }
 568         early_acpi_os_unmap_memory(dmar_tbl, dmar_tbl_size);
 569         dmar_tbl = NULL;
 570
 571         return ret ? 1 : -ENODEV;
 572 }
 573
 574
 575 static void unmap_iommu(struct intel_iommu *iommu)
 576 {
 577         iounmap(iommu->reg);
 578         release_mem_region(iommu->reg_phys, iommu->reg_size);
 579 }
 580
 581 /**
 582  * map_iommu: map the iommu's registers
 583  * @iommu: the iommu to map
 584  * @phys_addr: the physical address of the base resgister
 585  *
 586  * Memory map the iommu's registers.  Start w/ a single page, and
 587  * possibly expand if that turns out to be insufficent.
 588  */
 589 static int map_iommu(struct intel_iommu *iommu, u64 phys_addr)
 590 {
 591         int map_size, err=0;
 592
 593         iommu->reg_phys = phys_addr;
 594         iommu->reg_size = VTD_PAGE_SIZE;
 595
 596         if (!request_mem_region(iommu->reg_phys, iommu->reg_size, iommu->name)) {
 597                 pr_err("IOMMU: can't reserve memory\n");
 598                 err = -EBUSY;
 599                 goto out;
 600         }
 601
 602         iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
 603         if (!iommu->reg) {
 604                 pr_err("IOMMU: can't map the region\n");
 605                 err = -ENOMEM;
 606                 goto release;
 607         }
 608
 609         iommu->cap = dmar_readq(iommu->reg + DMAR_CAP_REG);
 610         iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG);
 611
 612         if (iommu->cap == (uint64_t)-1 && iommu->ecap == (uint64_t)-1) {
 613                 err = -EINVAL;
 614                 warn_invalid_dmar(phys_addr, " returns all ones");
 615                 goto unmap;
 616         }
 617
 618         /* the registers might be more than one page */
 619         map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),
 620                          cap_max_fault_reg_offset(iommu->cap));
 621         map_size = VTD_PAGE_ALIGN(map_size);
 622         if (map_size > iommu->reg_size) {
 623                 iounmap(iommu->reg);
 624                 release_mem_region(iommu->reg_phys, iommu->reg_size);
 625                 iommu->reg_size = map_size;
 626                 if (!request_mem_region(iommu->reg_phys, iommu->reg_size,
 627                                         iommu->name)) {
 628                         pr_err("IOMMU: can't reserve memory\n");
 629                         err = -EBUSY;
 630                         goto out;
 631                 }
 632                 iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
 633                 if (!iommu->reg) {
 634                         pr_err("IOMMU: can't map the region\n");
 635                         err = -ENOMEM;
 636                         goto release;
 637                 }
 638         }
 639         err = 0;
 640         goto out;
 641
 642 unmap:
 643         iounmap(iommu->reg);
 644 release:
 645         release_mem_region(iommu->reg_phys, iommu->reg_size);
 646 out:
 647         return err;
 648 }
 649
 650 int alloc_iommu(struct dmar_drhd_unit *drhd)
 651 {
 652         struct intel_iommu *iommu;
 653         u32 ver, sts;
 654         static int iommu_allocated = 0;
 655         int agaw = 0;
 656         int msagaw = 0;
 657         int err;
 658
 659         if (!drhd->reg_base_addr) {
 660                 warn_invalid_dmar(0, "");
 661                 return -EINVAL;
 662         }
 663
 664         iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
 665         if (!iommu)
 666                 return -ENOMEM;
 667
 668         iommu->seq_id = iommu_allocated++;
 669         sprintf (iommu->name, "dmar%d", iommu->seq_id);
 670
 671         err = map_iommu(iommu, drhd->reg_base_addr);
 672         if (err) {
 673                 pr_err("IOMMU: failed to map %s\n", iommu->name);
 674                 goto error;
 675         }
 676
 677         err = -EINVAL;
 678         agaw = iommu_calculate_agaw(iommu);
 679         if (agaw < 0) {
 680                 pr_err("Cannot get a valid agaw for iommu (seq_id = %d)\n",
 681                         iommu->seq_id);
 682                 goto err_unmap;
 683         }
 684         msagaw = iommu_calculate_max_sagaw(iommu);
 685         if (msagaw < 0) {
 686                 pr_err("Cannot get a valid max agaw for iommu (seq_id = %d)\n",
 687                         iommu->seq_id);
 688                 goto err_unmap;
 689         }
 690         iommu->agaw = agaw;
 691         iommu->msagaw = msagaw;
 692
 693         iommu->node = -1;
 694
 695         ver = readl(iommu->reg + DMAR_VER_REG);
 696         pr_info("IOMMU %d: reg_base_addr %llx ver %d:%d cap %llx ecap %llx\n",
 697                 iommu->seq_id,
 698                 (unsigned long long)drhd->reg_base_addr,
 699                 DMAR_VER_MAJOR(ver), DMAR_VER_MINOR(ver),
 700                 (unsigned long long)iommu->cap,
 701                 (unsigned long long)iommu->ecap);
 702
 703         /* Reflect status in gcmd */
 704         sts = readl(iommu->reg + DMAR_GSTS_REG);
 705         if (sts & DMA_GSTS_IRES)
 706                 iommu->gcmd |= DMA_GCMD_IRE;
 707         if (sts & DMA_GSTS_TES)
 708                 iommu->gcmd |= DMA_GCMD_TE;
 709         if (sts & DMA_GSTS_QIES)
 710                 iommu->gcmd |= DMA_GCMD_QIE;
 711
 712         raw_spin_lock_init(&iommu->register_lock);
 713
 714         drhd->iommu = iommu;
 715         return 0;
 716
 717  err_unmap:
 718         unmap_iommu(iommu);
 719  error:
 720         kfree(iommu);
 721         return err;
 722 }
 723
 724 void free_iommu(struct intel_iommu *iommu)
 725 {
 726         if (!iommu)
 727                 return;
 728
 729         free_dmar_iommu(iommu);
 730
 731         if (iommu->reg)
 732                 unmap_iommu(iommu);
 733
 734         kfree(iommu);
 735 }
 736
 737 /*
 738  * Reclaim all the submitted descriptors which have completed its work.
 739  */
 740 static inline void reclaim_free_desc(struct q_inval *qi)
 741 {
 742         while (qi->desc_status[qi->free_tail] == QI_DONE ||
 743                qi->desc_status[qi->free_tail] == QI_ABORT) {
 744                 qi->desc_status[qi->free_tail] = QI_FREE;
 745                 qi->free_tail = (qi->free_tail + 1) % QI_LENGTH;
 746                 qi->free_cnt++;
 747         }
 748 }
 749
 750 static int qi_check_fault(struct intel_iommu *iommu, int index)
 751 {
 752         u32 fault;
 753         int head, tail;
 754         struct q_inval *qi = iommu->qi;
 755         int wait_index = (index + 1) % QI_LENGTH;
 756
 757         if (qi->desc_status[wait_index] == QI_ABORT)
 758                 return -EAGAIN;
 759
 760         fault = readl(iommu->reg + DMAR_FSTS_REG);
 761
 762         /*
 763          * If IQE happens, the head points to the descriptor associated
 764          * with the error. No new descriptors are fetched until the IQE
 765          * is cleared.
 766          */
 767         if (fault & DMA_FSTS_IQE) {
 768                 head = readl(iommu->reg + DMAR_IQH_REG);
 769                 if ((head >> DMAR_IQ_SHIFT) == index) {
 770                         pr_err("VT-d detected invalid descriptor: "
 771                                 "low=%llx, high=%llx\n",
 772                                 (unsigned long long)qi->desc[index].low,
 773                                 (unsigned long long)qi->desc[index].high);
 774                         memcpy(&qi->desc[index], &qi->desc[wait_index],
 775                                         sizeof(struct qi_desc));
 776                         __iommu_flush_cache(iommu, &qi->desc[index],
 777                                         sizeof(struct qi_desc));
 778                         writel(DMA_FSTS_IQE, iommu->reg + DMAR_FSTS_REG);
 779                         return -EINVAL;
 780                 }
 781         }
 782
 783         /*
 784          * If ITE happens, all pending wait_desc commands are aborted.
 785          * No new descriptors are fetched until the ITE is cleared.
 786          */
 787         if (fault & DMA_FSTS_ITE) {
 788                 head = readl(iommu->reg + DMAR_IQH_REG);
 789                 head = ((head >> DMAR_IQ_SHIFT) - 1 + QI_LENGTH) % QI_LENGTH;
 790                 head |= 1;
 791                 tail = readl(iommu->reg + DMAR_IQT_REG);
 792                 tail = ((tail >> DMAR_IQ_SHIFT) - 1 + QI_LENGTH) % QI_LENGTH;
 793
 794                 writel(DMA_FSTS_ITE, iommu->reg + DMAR_FSTS_REG);
 795
 796                 do {
 797                         if (qi->desc_status[head] == QI_IN_USE)
 798                                 qi->desc_status[head] = QI_ABORT;
 799                         head = (head - 2 + QI_LENGTH) % QI_LENGTH;
 800                 } while (head != tail);
 801
 802                 if (qi->desc_status[wait_index] == QI_ABORT)
 803                         return -EAGAIN;
 804         }
 805
 806         if (fault & DMA_FSTS_ICE)
 807                 writel(DMA_FSTS_ICE, iommu->reg + DMAR_FSTS_REG);
 808
 809         return 0;
 810 }
 811
 812 /*
 813  * Submit the queued invalidation descriptor to the remapping
 814  * hardware unit and wait for its completion.
 815  */
 816 int qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu)
 817 {
 818         int rc;
 819         struct q_inval *qi = iommu->qi;
 820         struct qi_desc *hw, wait_desc;
 821         int wait_index, index;
 822         unsigned long flags;
 823
 824         if (!qi)
 825                 return 0;
 826
 827         hw = qi->desc;
 828
 829 restart:
 830         rc = 0;
 831
 832         raw_spin_lock_irqsave(&qi->q_lock, flags);
 833         while (qi->free_cnt < 3) {
 834                 raw_spin_unlock_irqrestore(&qi->q_lock, flags);
 835                 cpu_relax();
 836                 raw_spin_lock_irqsave(&qi->q_lock, flags);
 837         }
 838
 839         index = qi->free_head;
 840         wait_index = (index + 1) % QI_LENGTH;
 841
 842         qi->desc_status[index] = qi->desc_status[wait_index] = QI_IN_USE;
 843
 844         hw[index] = *desc;
 845
 846         wait_desc.low = QI_IWD_STATUS_DATA(QI_DONE) |
 847                         QI_IWD_STATUS_WRITE | QI_IWD_TYPE;
 848         wait_desc.high = virt_to_phys(&qi->desc_status[wait_index]);
 849
 850         hw[wait_index] = wait_desc;
 851
 852         __iommu_flush_cache(iommu, &hw[index], sizeof(struct qi_desc));
 853         __iommu_flush_cache(iommu, &hw[wait_index], sizeof(struct qi_desc));
 854
 855         qi->free_head = (qi->free_head + 2) % QI_LENGTH;
 856         qi->free_cnt -= 2;
 857
 858         /*
 859          * update the HW tail register indicating the presence of
 860          * new descriptors.
 861          */
 862         writel(qi->free_head << DMAR_IQ_SHIFT, iommu->reg + DMAR_IQT_REG);
 863
 864         while (qi->desc_status[wait_index] != QI_DONE) {
 865                 /*
 866                  * We will leave the interrupts disabled, to prevent interrupt
 867                  * context to queue another cmd while a cmd is already submitted
 868                  * and waiting for completion on this cpu. This is to avoid
 869                  * a deadlock where the interrupt context can wait indefinitely
 870                  * for free slots in the queue.
 871                  */
 872                 rc = qi_check_fault(iommu, index);
 873                 if (rc)
 874                         break;
 875
 876                 raw_spin_unlock(&qi->q_lock);
 877                 cpu_relax();
 878                 raw_spin_lock(&qi->q_lock);
 879         }
 880
 881         qi->desc_status[index] = QI_DONE;
 882
 883         reclaim_free_desc(qi);
 884         raw_spin_unlock_irqrestore(&qi->q_lock, flags);
 885
 886         if (rc == -EAGAIN)
 887                 goto restart;
 888
 889         return rc;
 890 }
 891
 892 /*
 893  * Flush the global interrupt entry cache.
 894  */
 895 void qi_global_iec(struct intel_iommu *iommu)
 896 {
 897         struct qi_desc desc;
 898
 899         desc.low = QI_IEC_TYPE;
 900         desc.high = 0;
 901
 902         /* should never fail */
 903         qi_submit_sync(&desc, iommu);
 904 }
 905
 906 void qi_flush_context(struct intel_iommu *iommu, u16 did, u16 sid, u8 fm,
 907                       u64 type)
 908 {
 909         struct qi_desc desc;
 910
 911         desc.low = QI_CC_FM(fm) | QI_CC_SID(sid) | QI_CC_DID(did)
 912                         | QI_CC_GRAN(type) | QI_CC_TYPE;
 913         desc.high = 0;
 914
 915         qi_submit_sync(&desc, iommu);
 916 }
 917
 918 void qi_flush_iotlb(struct intel_iommu *iommu, u16 did, u64 addr,
 919                     unsigned int size_order, u64 type)
 920 {
 921         u8 dw = 0, dr = 0;
 922
 923         struct qi_desc desc;
 924         int ih = 0;
 925
 926         if (cap_write_drain(iommu->cap))
 927                 dw = 1;
 928
 929         if (cap_read_drain(iommu->cap))
 930                 dr = 1;
 931
 932         desc.low = QI_IOTLB_DID(did) | QI_IOTLB_DR(dr) | QI_IOTLB_DW(dw)
 933                 | QI_IOTLB_GRAN(type) | QI_IOTLB_TYPE;
 934         desc.high = QI_IOTLB_ADDR(addr) | QI_IOTLB_IH(ih)
 935                 | QI_IOTLB_AM(size_order);
 936
 937         qi_submit_sync(&desc, iommu);
 938 }
 939
 940 void qi_flush_dev_iotlb(struct intel_iommu *iommu, u16 sid, u16 qdep,
 941                         u64 addr, unsigned mask)
 942 {
 943         struct qi_desc desc;
 944
 945         if (mask) {
 946                 BUG_ON(addr & ((1 << (VTD_PAGE_SHIFT + mask)) - 1));
 947                 addr |= (1 << (VTD_PAGE_SHIFT + mask - 1)) - 1;
 948                 desc.high = QI_DEV_IOTLB_ADDR(addr) | QI_DEV_IOTLB_SIZE;
 949         } else
 950                 desc.high = QI_DEV_IOTLB_ADDR(addr);
 951
 952         if (qdep >= QI_DEV_IOTLB_MAX_INVS)
 953                 qdep = 0;
 954
 955         desc.low = QI_DEV_IOTLB_SID(sid) | QI_DEV_IOTLB_QDEP(qdep) |
 956                    QI_DIOTLB_TYPE;
 957
 958         qi_submit_sync(&desc, iommu);
 959 }
 960
 961 /*
 962  * Disable Queued Invalidation interface.
 963  */
 964 void dmar_disable_qi(struct intel_iommu *iommu)
 965 {
 966         unsigned long flags;
 967         u32 sts;
 968         cycles_t start_time = get_cycles();
 969
 970         if (!ecap_qis(iommu->ecap))
 971                 return;
 972
 973         raw_spin_lock_irqsave(&iommu->register_lock, flags);
 974
 975         sts =  dmar_readq(iommu->reg + DMAR_GSTS_REG);
 976         if (!(sts & DMA_GSTS_QIES))
 977                 goto end;
 978
 979         /*
 980          * Give a chance to HW to complete the pending invalidation requests.
 981          */
 982         while ((readl(iommu->reg + DMAR_IQT_REG) !=
 983                 readl(iommu->reg + DMAR_IQH_REG)) &&
 984                 (DMAR_OPERATION_TIMEOUT > (get_cycles() - start_time)))
 985                 cpu_relax();
 986
 987         iommu->gcmd &= ~DMA_GCMD_QIE;
 988         writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
 989
 990         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl,
 991                       !(sts & DMA_GSTS_QIES), sts);
 992 end:
 993         raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
 994 }
 995
 996 /*
 997  * Enable queued invalidation.
 998  */
 999 static void __dmar_enable_qi(struct intel_iommu *iommu)
1000 {
1001         u32 sts;
1002         unsigned long flags;
1003         struct q_inval *qi = iommu->qi;
1004
1005         qi->free_head = qi->free_tail = 0;
1006         qi->free_cnt = QI_LENGTH;
1007
1008         raw_spin_lock_irqsave(&iommu->register_lock, flags);
1009
1010         /* write zero to the tail reg */
1011         writel(0, iommu->reg + DMAR_IQT_REG);
1012
1013         dmar_writeq(iommu->reg + DMAR_IQA_REG, virt_to_phys(qi->desc));
1014
1015         iommu->gcmd |= DMA_GCMD_QIE;
1016         writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
1017
1018         /* Make sure hardware complete it */
1019         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl, (sts & DMA_GSTS_QIES), sts);
1020
1021         raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
1022 }
1023
1024 /*
1025  * Enable Queued Invalidation interface. This is a must to support
1026  * interrupt-remapping. Also used by DMA-remapping, which replaces
1027  * register based IOTLB invalidation.
1028  */
1029 int dmar_enable_qi(struct intel_iommu *iommu)
1030 {
1031         struct q_inval *qi;
1032         struct page *desc_page;
1033
1034         if (!ecap_qis(iommu->ecap))
1035                 return -ENOENT;
1036
1037         /*
1038          * queued invalidation is already setup and enabled.
1039          */
1040         if (iommu->qi)
1041                 return 0;
1042
1043         iommu->qi = kmalloc(sizeof(*qi), GFP_ATOMIC);
1044         if (!iommu->qi)
1045                 return -ENOMEM;
1046
1047         qi = iommu->qi;
1048
1049
1050         desc_page = alloc_pages_node(iommu->node, GFP_ATOMIC | __GFP_ZERO, 0);
1051         if (!desc_page) {
1052                 kfree(qi);
1053                 iommu->qi = 0;
1054                 return -ENOMEM;
1055         }
1056
1057         qi->desc = page_address(desc_page);
1058
1059         qi->desc_status = kzalloc(QI_LENGTH * sizeof(int), GFP_ATOMIC);
1060         if (!qi->desc_status) {
1061                 free_page((unsigned long) qi->desc);
1062                 kfree(qi);
1063                 iommu->qi = 0;
1064                 return -ENOMEM;
1065         }
1066
1067         qi->free_head = qi->free_tail = 0;
1068         qi->free_cnt = QI_LENGTH;
1069
1070         raw_spin_lock_init(&qi->q_lock);
1071
1072         __dmar_enable_qi(iommu);
1073
1074         return 0;
1075 }
1076
1077 /* iommu interrupt handling. Most stuff are MSI-like. */
1078
1079 enum faulttype {
1080         DMA_REMAP,
1081         INTR_REMAP,
1082         UNKNOWN,
1083 };
1084
1085 static const char *dma_remap_fault_reasons[] =
1086 {
1087         "Software",
1088         "Present bit in root entry is clear",
1089         "Present bit in context entry is clear",
1090         "Invalid context entry",
1091         "Access beyond MGAW",
1092         "PTE Write access is not set",
1093         "PTE Read access is not set",
1094         "Next page table ptr is invalid",
1095         "Root table address invalid",
1096         "Context table ptr is invalid",
1097         "non-zero reserved fields in RTP",
1098         "non-zero reserved fields in CTP",
1099         "non-zero reserved fields in PTE",
1100         "PCE for translation request specifies blocking",
1101 };
1102
1103 static const char *irq_remap_fault_reasons[] =
1104 {
1105         "Detected reserved fields in the decoded interrupt-remapped request",
1106         "Interrupt index exceeded the interrupt-remapping table size",
1107         "Present field in the IRTE entry is clear",
1108         "Error accessing interrupt-remapping table pointed by IRTA_REG",
1109         "Detected reserved fields in the IRTE entry",
1110         "Blocked a compatibility format interrupt request",
1111         "Blocked an interrupt request due to source-id verification failure",
1112 };
1113
1114 #define MAX_FAULT_REASON_IDX    (ARRAY_SIZE(fault_reason_strings) - 1)
1115
1116 const char *dmar_get_fault_reason(u8 fault_reason, int *fault_type)
1117 {
1118         if (fault_reason >= 0x20 && (fault_reason - 0x20 <
1119                                         ARRAY_SIZE(irq_remap_fault_reasons))) {
1120                 *fault_type = INTR_REMAP;
1121                 return irq_remap_fault_reasons[fault_reason - 0x20];
1122         } else if (fault_reason < ARRAY_SIZE(dma_remap_fault_reasons)) {
1123                 *fault_type = DMA_REMAP;
1124                 return dma_remap_fault_reasons[fault_reason];
1125         } else {
1126                 *fault_type = UNKNOWN;
1127                 return "Unknown";
1128         }
1129 }
1130
1131 void dmar_msi_unmask(struct irq_data *data)
1132 {
1133         struct intel_iommu *iommu = irq_data_get_irq_handler_data(data);
1134         unsigned long flag;
1135
1136         /* unmask it */
1137         raw_spin_lock_irqsave(&iommu->register_lock, flag);
1138         writel(0, iommu->reg + DMAR_FECTL_REG);
1139         /* Read a reg to force flush the post write */
1140         readl(iommu->reg + DMAR_FECTL_REG);
1141         raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1142 }
1143
1144 void dmar_msi_mask(struct irq_data *data)
1145 {
1146         unsigned long flag;
1147         struct intel_iommu *iommu = irq_data_get_irq_handler_data(data);
1148
1149         /* mask it */
1150         raw_spin_lock_irqsave(&iommu->register_lock, flag);
1151         writel(DMA_FECTL_IM, iommu->reg + DMAR_FECTL_REG);
1152         /* Read a reg to force flush the post write */
1153         readl(iommu->reg + DMAR_FECTL_REG);
1154         raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1155 }
1156
1157 void dmar_msi_write(int irq, struct msi_msg *msg)
1158 {
1159         struct intel_iommu *iommu = irq_get_handler_data(irq);
1160         unsigned long flag;
1161
1162         raw_spin_lock_irqsave(&iommu->register_lock, flag);
1163         writel(msg->data, iommu->reg + DMAR_FEDATA_REG);
1164         writel(msg->address_lo, iommu->reg + DMAR_FEADDR_REG);
1165         writel(msg->address_hi, iommu->reg + DMAR_FEUADDR_REG);
1166         raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1167 }
1168
1169 void dmar_msi_read(int irq, struct msi_msg *msg)
1170 {
1171         struct intel_iommu *iommu = irq_get_handler_data(irq);
1172         unsigned long flag;
1173
1174         raw_spin_lock_irqsave(&iommu->register_lock, flag);
1175         msg->data = readl(iommu->reg + DMAR_FEDATA_REG);
1176         msg->address_lo = readl(iommu->reg + DMAR_FEADDR_REG);
1177         msg->address_hi = readl(iommu->reg + DMAR_FEUADDR_REG);
1178         raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1179 }
1180
1181 static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
1182                 u8 fault_reason, u16 source_id, unsigned long long addr)
1183 {
1184         const char *reason;
1185         int fault_type;
1186
1187         reason = dmar_get_fault_reason(fault_reason, &fault_type);
1188
1189         if (fault_type == INTR_REMAP)
1190                 pr_err("INTR-REMAP: Request device [[%02x:%02x.%d] "
1191                        "fault index %llx\n"
1192                         "INTR-REMAP:[fault reason %02d] %s\n",
1193                         (source_id >> 8), PCI_SLOT(source_id & 0xFF),
1194                         PCI_FUNC(source_id & 0xFF), addr >> 48,
1195                         fault_reason, reason);
1196         else
1197                 pr_err("DMAR:[%s] Request device [%02x:%02x.%d] "
1198                        "fault addr %llx \n"
1199                        "DMAR:[fault reason %02d] %s\n",
1200                        (type ? "DMA Read" : "DMA Write"),
1201                        (source_id >> 8), PCI_SLOT(source_id & 0xFF),
1202                        PCI_FUNC(source_id & 0xFF), addr, fault_reason, reason);
1203         return 0;
1204 }
1205
1206 #define PRIMARY_FAULT_REG_LEN (16)
1207 irqreturn_t dmar_fault(int irq, void *dev_id)
1208 {
1209         struct intel_iommu *iommu = dev_id;
1210         int reg, fault_index;
1211         u32 fault_status;
1212         unsigned long flag;
1213
1214         raw_spin_lock_irqsave(&iommu->register_lock, flag);
1215         fault_status = readl(iommu->reg + DMAR_FSTS_REG);
1216         if (fault_status)
1217                 pr_err("DRHD: handling fault status reg %x\n", fault_status);
1218
1219         /* TBD: ignore advanced fault log currently */
1220         if (!(fault_status & DMA_FSTS_PPF))
1221                 goto unlock_exit;
1222
1223         fault_index = dma_fsts_fault_record_index(fault_status);
1224         reg = cap_fault_reg_offset(iommu->cap);
1225         while (1) {
1226                 u8 fault_reason;
1227                 u16 source_id;
1228                 u64 guest_addr;
1229                 int type;
1230                 u32 data;
1231
1232                 /* highest 32 bits */
1233                 data = readl(iommu->reg + reg +
1234                                 fault_index * PRIMARY_FAULT_REG_LEN + 12);
1235                 if (!(data & DMA_FRCD_F))
1236                         break;
1237
1238                 fault_reason = dma_frcd_fault_reason(data);
1239                 type = dma_frcd_type(data);
1240
1241                 data = readl(iommu->reg + reg +
1242                                 fault_index * PRIMARY_FAULT_REG_LEN + 8);
1243                 source_id = dma_frcd_source_id(data);
1244
1245                 guest_addr = dmar_readq(iommu->reg + reg +
1246                                 fault_index * PRIMARY_FAULT_REG_LEN);
1247                 guest_addr = dma_frcd_page_addr(guest_addr);
1248                 /* clear the fault */
1249                 writel(DMA_FRCD_F, iommu->reg + reg +
1250                         fault_index * PRIMARY_FAULT_REG_LEN + 12);
1251
1252                 raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1253
1254                 dmar_fault_do_one(iommu, type, fault_reason,
1255                                 source_id, guest_addr);
1256
1257                 fault_index++;
1258                 if (fault_index >= cap_num_fault_regs(iommu->cap))
1259                         fault_index = 0;
1260                 raw_spin_lock_irqsave(&iommu->register_lock, flag);
1261         }
1262
1263         writel(DMA_FSTS_PFO | DMA_FSTS_PPF, iommu->reg + DMAR_FSTS_REG);
1264
1265 unlock_exit:
1266         raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1267         return IRQ_HANDLED;
1268 }
1269
1270 int dmar_set_interrupt(struct intel_iommu *iommu)
1271 {
1272         int irq, ret;
1273
1274         /*
1275          * Check if the fault interrupt is already initialized.
1276          */
1277         if (iommu->irq)
1278                 return 0;
1279
1280         irq = create_irq();
1281         if (!irq) {
1282                 pr_err("IOMMU: no free vectors\n");
1283                 return -EINVAL;
1284         }
1285
1286         irq_set_handler_data(irq, iommu);
1287         iommu->irq = irq;
1288
1289         ret = arch_setup_dmar_msi(irq);
1290         if (ret) {
1291                 irq_set_handler_data(irq, NULL);
1292                 iommu->irq = 0;
1293                 destroy_irq(irq);
1294                 return ret;
1295         }
1296
1297         ret = request_irq(irq, dmar_fault, IRQF_NO_THREAD, iommu->name, iommu);
1298         if (ret)
1299                 pr_err("IOMMU: can't request irq\n");
1300         return ret;
1301 }
1302
1303 int __init enable_drhd_fault_handling(void)
1304 {
1305         struct dmar_drhd_unit *drhd;
1306
1307         /*
1308          * Enable fault control interrupt.
1309          */
1310         for_each_drhd_unit(drhd) {
1311                 int ret;
1312                 struct intel_iommu *iommu = drhd->iommu;
1313                 u32 fault_status;
1314                 ret = dmar_set_interrupt(iommu);
1315
1316                 if (ret) {
1317                         pr_err("DRHD %Lx: failed to enable fault, interrupt, ret %d\n",
1318                                (unsigned long long)drhd->reg_base_addr, ret);
1319                         return -1;
1320                 }
1321
1322                 /*
1323                  * Clear any previous faults.
1324                  */
1325                 dmar_fault(iommu->irq, iommu);
1326                 fault_status = readl(iommu->reg + DMAR_FSTS_REG);
1327                 writel(fault_status, iommu->reg + DMAR_FSTS_REG);
1328         }
1329
1330         return 0;
1331 }
1332
1333 /*
1334  * Re-enable Queued Invalidation interface.
1335  */
1336 int dmar_reenable_qi(struct intel_iommu *iommu)
1337 {
1338         if (!ecap_qis(iommu->ecap))
1339                 return -ENOENT;
1340
1341         if (!iommu->qi)
1342                 return -ENOENT;
1343
1344         /*
1345          * First disable queued invalidation.
1346          */
1347         dmar_disable_qi(iommu);
1348         /*
1349          * Then enable queued invalidation again. Since there is no pending
1350          * invalidation requests now, it's safe to re-enable queued
1351          * invalidation.
1352          */
1353         __dmar_enable_qi(iommu);
1354
1355         return 0;
1356 }
1357
1358 /*
1359  * Check interrupt remapping support in DMAR table description.
1360  */
1361 int __init dmar_ir_support(void)
1362 {
1363         struct acpi_table_dmar *dmar;
1364         dmar = (struct acpi_table_dmar *)dmar_tbl;
1365         if (!dmar)
1366                 return 0;
1367         return dmar->flags & 0x1;
1368 }
1369 IOMMU_INIT_POST(detect_intel_iommu);