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)     "DMAR: " fmt
  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 <linux/iommu.h>
  42 #include <asm/irq_remapping.h>
  43 #include <asm/iommu_table.h>
  44
  45 #include "irq_remapping.h"
  46
  47 typedef int (*dmar_res_handler_t)(struct acpi_dmar_header *, void *);
  48 struct dmar_res_callback {
  49         dmar_res_handler_t      cb[ACPI_DMAR_TYPE_RESERVED];
  50         void                    *arg[ACPI_DMAR_TYPE_RESERVED];
  51         bool                    ignore_unhandled;
  52         bool                    print_entry;
  53 };
  54
  55 /*
  56  * Assumptions:
  57  * 1) The hotplug framework guarentees that DMAR unit will be hot-added
  58  *    before IO devices managed by that unit.
  59  * 2) The hotplug framework guarantees that DMAR unit will be hot-removed
  60  *    after IO devices managed by that unit.
  61  * 3) Hotplug events are rare.
  62  *
  63  * Locking rules for DMA and interrupt remapping related global data structures:
  64  * 1) Use dmar_global_lock in process context
  65  * 2) Use RCU in interrupt context
  66  */
  67 DECLARE_RWSEM(dmar_global_lock);
  68 LIST_HEAD(dmar_drhd_units);
  69
  70 struct acpi_table_header * __initdata dmar_tbl;
  71 static int dmar_dev_scope_status = 1;
  72 static unsigned long dmar_seq_ids[BITS_TO_LONGS(DMAR_UNITS_SUPPORTED)];
  73
  74 static int alloc_iommu(struct dmar_drhd_unit *drhd);
  75 static void free_iommu(struct intel_iommu *iommu);
  76
  77 extern const struct iommu_ops intel_iommu_ops;
  78
  79 static void dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
  80 {
  81         /*
  82          * add INCLUDE_ALL at the tail, so scan the list will find it at
  83          * the very end.
  84          */
  85         if (drhd->include_all)
  86                 list_add_tail_rcu(&drhd->list, &dmar_drhd_units);
  87         else
  88                 list_add_rcu(&drhd->list, &dmar_drhd_units);
  89 }
  90
  91 void *dmar_alloc_dev_scope(void *start, void *end, int *cnt)
  92 {
  93         struct acpi_dmar_device_scope *scope;
  94
  95         *cnt = 0;
  96         while (start < end) {
  97                 scope = start;
  98                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_NAMESPACE ||
  99                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
 100                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE)
 101                         (*cnt)++;
 102                 else if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_IOAPIC &&
 103                         scope->entry_type != ACPI_DMAR_SCOPE_TYPE_HPET) {
 104                         pr_warn("Unsupported device scope\n");
 105                 }
 106                 start += scope->length;
 107         }
 108         if (*cnt == 0)
 109                 return NULL;
 110
 111         return kcalloc(*cnt, sizeof(struct dmar_dev_scope), GFP_KERNEL);
 112 }
 113
 114 void dmar_free_dev_scope(struct dmar_dev_scope **devices, int *cnt)
 115 {
 116         int i;
 117         struct device *tmp_dev;
 118
 119         if (*devices && *cnt) {
 120                 for_each_active_dev_scope(*devices, *cnt, i, tmp_dev)
 121                         put_device(tmp_dev);
 122                 kfree(*devices);
 123         }
 124
 125         *devices = NULL;
 126         *cnt = 0;
 127 }
 128
 129 /* Optimize out kzalloc()/kfree() for normal cases */
 130 static char dmar_pci_notify_info_buf[64];
 131
 132 static struct dmar_pci_notify_info *
 133 dmar_alloc_pci_notify_info(struct pci_dev *dev, unsigned long event)
 134 {
 135         int level = 0;
 136         size_t size;
 137         struct pci_dev *tmp;
 138         struct dmar_pci_notify_info *info;
 139
 140         BUG_ON(dev->is_virtfn);
 141
 142         /* Only generate path[] for device addition event */
 143         if (event == BUS_NOTIFY_ADD_DEVICE)
 144                 for (tmp = dev; tmp; tmp = tmp->bus->self)
 145                         level++;
 146
 147         size = sizeof(*info) + level * sizeof(struct acpi_dmar_pci_path);
 148         if (size <= sizeof(dmar_pci_notify_info_buf)) {
 149                 info = (struct dmar_pci_notify_info *)dmar_pci_notify_info_buf;
 150         } else {
 151                 info = kzalloc(size, GFP_KERNEL);
 152                 if (!info) {
 153                         pr_warn("Out of memory when allocating notify_info "
 154                                 "for %s.\n", pci_name(dev));
 155                         if (dmar_dev_scope_status == 0)
 156                                 dmar_dev_scope_status = -ENOMEM;
 157                         return NULL;
 158                 }
 159         }
 160
 161         info->event = event;
 162         info->dev = dev;
 163         info->seg = pci_domain_nr(dev->bus);
 164         info->level = level;
 165         if (event == BUS_NOTIFY_ADD_DEVICE) {
 166                 for (tmp = dev; tmp; tmp = tmp->bus->self) {
 167                         level--;
 168                         info->path[level].bus = tmp->bus->number;
 169                         info->path[level].device = PCI_SLOT(tmp->devfn);
 170                         info->path[level].function = PCI_FUNC(tmp->devfn);
 171                         if (pci_is_root_bus(tmp->bus))
 172                                 info->bus = tmp->bus->number;
 173                 }
 174         }
 175
 176         return info;
 177 }
 178
 179 static inline void dmar_free_pci_notify_info(struct dmar_pci_notify_info *info)
 180 {
 181         if ((void *)info != dmar_pci_notify_info_buf)
 182                 kfree(info);
 183 }
 184
 185 static bool dmar_match_pci_path(struct dmar_pci_notify_info *info, int bus,
 186                                 struct acpi_dmar_pci_path *path, int count)
 187 {
 188         int i;
 189
 190         if (info->bus != bus)
 191                 goto fallback;
 192         if (info->level != count)
 193                 goto fallback;
 194
 195         for (i = 0; i < count; i++) {
 196                 if (path[i].device != info->path[i].device ||
 197                     path[i].function != info->path[i].function)
 198                         goto fallback;
 199         }
 200
 201         return true;
 202
 203 fallback:
 204
 205         if (count != 1)
 206                 return false;
 207
 208         i = info->level - 1;
 209         if (bus              == info->path[i].bus &&
 210             path[0].device   == info->path[i].device &&
 211             path[0].function == info->path[i].function) {
 212                 pr_info(FW_BUG "RMRR entry for device %02x:%02x.%x is broken - applying workaround\n",
 213                         bus, path[0].device, path[0].function);
 214                 return true;
 215         }
 216
 217         return false;
 218 }
 219
 220 /* Return: > 0 if match found, 0 if no match found, < 0 if error happens */
 221 int dmar_insert_dev_scope(struct dmar_pci_notify_info *info,
 222                           void *start, void*end, u16 segment,
 223                           struct dmar_dev_scope *devices,
 224                           int devices_cnt)
 225 {
 226         int i, level;
 227         struct device *tmp, *dev = &info->dev->dev;
 228         struct acpi_dmar_device_scope *scope;
 229         struct acpi_dmar_pci_path *path;
 230
 231         if (segment != info->seg)
 232                 return 0;
 233
 234         for (; start < end; start += scope->length) {
 235                 scope = start;
 236                 if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_ENDPOINT &&
 237                     scope->entry_type != ACPI_DMAR_SCOPE_TYPE_BRIDGE)
 238                         continue;
 239
 240                 path = (struct acpi_dmar_pci_path *)(scope + 1);
 241                 level = (scope->length - sizeof(*scope)) / sizeof(*path);
 242                 if (!dmar_match_pci_path(info, scope->bus, path, level))
 243                         continue;
 244
 245                 /*
 246                  * We expect devices with endpoint scope to have normal PCI
 247                  * headers, and devices with bridge scope to have bridge PCI
 248                  * headers.  However PCI NTB devices may be listed in the
 249                  * DMAR table with bridge scope, even though they have a
 250                  * normal PCI header.  NTB devices are identified by class
 251                  * "BRIDGE_OTHER" (0680h) - we don't declare a socpe mismatch
 252                  * for this special case.
 253                  */
 254                 if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT &&
 255                      info->dev->hdr_type != PCI_HEADER_TYPE_NORMAL) ||
 256                     (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE &&
 257                      (info->dev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
 258                       info->dev->class >> 8 != PCI_CLASS_BRIDGE_OTHER))) {
 259                         pr_warn("Device scope type does not match for %s\n",
 260                                 pci_name(info->dev));
 261                         return -EINVAL;
 262                 }
 263
 264                 for_each_dev_scope(devices, devices_cnt, i, tmp)
 265                         if (tmp == NULL) {
 266                                 devices[i].bus = info->dev->bus->number;
 267                                 devices[i].devfn = info->dev->devfn;
 268                                 rcu_assign_pointer(devices[i].dev,
 269                                                    get_device(dev));
 270                                 return 1;
 271                         }
 272                 BUG_ON(i >= devices_cnt);
 273         }
 274
 275         return 0;
 276 }
 277
 278 int dmar_remove_dev_scope(struct dmar_pci_notify_info *info, u16 segment,
 279                           struct dmar_dev_scope *devices, int count)
 280 {
 281         int index;
 282         struct device *tmp;
 283
 284         if (info->seg != segment)
 285                 return 0;
 286
 287         for_each_active_dev_scope(devices, count, index, tmp)
 288                 if (tmp == &info->dev->dev) {
 289                         RCU_INIT_POINTER(devices[index].dev, NULL);
 290                         synchronize_rcu();
 291                         put_device(tmp);
 292                         return 1;
 293                 }
 294
 295         return 0;
 296 }
 297
 298 static int dmar_pci_bus_add_dev(struct dmar_pci_notify_info *info)
 299 {
 300         int ret = 0;
 301         struct dmar_drhd_unit *dmaru;
 302         struct acpi_dmar_hardware_unit *drhd;
 303
 304         for_each_drhd_unit(dmaru) {
 305                 if (dmaru->include_all)
 306                         continue;
 307
 308                 drhd = container_of(dmaru->hdr,
 309                                     struct acpi_dmar_hardware_unit, header);
 310                 ret = dmar_insert_dev_scope(info, (void *)(drhd + 1),
 311                                 ((void *)drhd) + drhd->header.length,
 312                                 dmaru->segment,
 313                                 dmaru->devices, dmaru->devices_cnt);
 314                 if (ret)
 315                         break;
 316         }
 317         if (ret >= 0)
 318                 ret = dmar_iommu_notify_scope_dev(info);
 319         if (ret < 0 && dmar_dev_scope_status == 0)
 320                 dmar_dev_scope_status = ret;
 321
 322         return ret;
 323 }
 324
 325 static void  dmar_pci_bus_del_dev(struct dmar_pci_notify_info *info)
 326 {
 327         struct dmar_drhd_unit *dmaru;
 328
 329         for_each_drhd_unit(dmaru)
 330                 if (dmar_remove_dev_scope(info, dmaru->segment,
 331                         dmaru->devices, dmaru->devices_cnt))
 332                         break;
 333         dmar_iommu_notify_scope_dev(info);
 334 }
 335
 336 static int dmar_pci_bus_notifier(struct notifier_block *nb,
 337                                  unsigned long action, void *data)
 338 {
 339         struct pci_dev *pdev = to_pci_dev(data);
 340         struct dmar_pci_notify_info *info;
 341
 342         /* Only care about add/remove events for physical functions.
 343          * For VFs we actually do the lookup based on the corresponding
 344          * PF in device_to_iommu() anyway. */
 345         if (pdev->is_virtfn)
 346                 return NOTIFY_DONE;
 347         if (action != BUS_NOTIFY_ADD_DEVICE &&
 348             action != BUS_NOTIFY_REMOVED_DEVICE)
 349                 return NOTIFY_DONE;
 350
 351         info = dmar_alloc_pci_notify_info(pdev, action);
 352         if (!info)
 353                 return NOTIFY_DONE;
 354
 355         down_write(&dmar_global_lock);
 356         if (action == BUS_NOTIFY_ADD_DEVICE)
 357                 dmar_pci_bus_add_dev(info);
 358         else if (action == BUS_NOTIFY_REMOVED_DEVICE)
 359                 dmar_pci_bus_del_dev(info);
 360         up_write(&dmar_global_lock);
 361
 362         dmar_free_pci_notify_info(info);
 363
 364         return NOTIFY_OK;
 365 }
 366
 367 static struct notifier_block dmar_pci_bus_nb = {
 368         .notifier_call = dmar_pci_bus_notifier,
 369         .priority = INT_MIN,
 370 };
 371
 372 static struct dmar_drhd_unit *
 373 dmar_find_dmaru(struct acpi_dmar_hardware_unit *drhd)
 374 {
 375         struct dmar_drhd_unit *dmaru;
 376
 377         list_for_each_entry_rcu(dmaru, &dmar_drhd_units, list)
 378                 if (dmaru->segment == drhd->segment &&
 379                     dmaru->reg_base_addr == drhd->address)
 380                         return dmaru;
 381
 382         return NULL;
 383 }
 384
 385 /**
 386  * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition
 387  * structure which uniquely represent one DMA remapping hardware unit
 388  * present in the platform
 389  */
 390 static int dmar_parse_one_drhd(struct acpi_dmar_header *header, void *arg)
 391 {
 392         struct acpi_dmar_hardware_unit *drhd;
 393         struct dmar_drhd_unit *dmaru;
 394         int ret;
 395
 396         drhd = (struct acpi_dmar_hardware_unit *)header;
 397         dmaru = dmar_find_dmaru(drhd);
 398         if (dmaru)
 399                 goto out;
 400
 401         dmaru = kzalloc(sizeof(*dmaru) + header->length, GFP_KERNEL);
 402         if (!dmaru)
 403                 return -ENOMEM;
 404
 405         /*
 406          * If header is allocated from slab by ACPI _DSM method, we need to
 407          * copy the content because the memory buffer will be freed on return.
 408          */
 409         dmaru->hdr = (void *)(dmaru + 1);
 410         memcpy(dmaru->hdr, header, header->length);
 411         dmaru->reg_base_addr = drhd->address;
 412         dmaru->segment = drhd->segment;
 413         dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */
 414         dmaru->devices = dmar_alloc_dev_scope((void *)(drhd + 1),
 415                                               ((void *)drhd) + drhd->header.length,
 416                                               &dmaru->devices_cnt);
 417         if (dmaru->devices_cnt && dmaru->devices == NULL) {
 418                 kfree(dmaru);
 419                 return -ENOMEM;
 420         }
 421
 422         ret = alloc_iommu(dmaru);
 423         if (ret) {
 424                 dmar_free_dev_scope(&dmaru->devices,
 425                                     &dmaru->devices_cnt);
 426                 kfree(dmaru);
 427                 return ret;
 428         }
 429         dmar_register_drhd_unit(dmaru);
 430
 431 out:
 432         if (arg)
 433                 (*(int *)arg)++;
 434
 435         return 0;
 436 }
 437
 438 static void dmar_free_drhd(struct dmar_drhd_unit *dmaru)
 439 {
 440         if (dmaru->devices && dmaru->devices_cnt)
 441                 dmar_free_dev_scope(&dmaru->devices, &dmaru->devices_cnt);
 442         if (dmaru->iommu)
 443                 free_iommu(dmaru->iommu);
 444         kfree(dmaru);
 445 }
 446
 447 static int __init dmar_parse_one_andd(struct acpi_dmar_header *header,
 448                                       void *arg)
 449 {
 450         struct acpi_dmar_andd *andd = (void *)header;
 451
 452         /* Check for NUL termination within the designated length */
 453         if (strnlen(andd->device_name, header->length - 8) == header->length - 8) {
 454                 WARN_TAINT(1, TAINT_FIRMWARE_WORKAROUND,
 455                            "Your BIOS is broken; ANDD object name is not NUL-terminated\n"
 456                            "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
 457                            dmi_get_system_info(DMI_BIOS_VENDOR),
 458                            dmi_get_system_info(DMI_BIOS_VERSION),
 459                            dmi_get_system_info(DMI_PRODUCT_VERSION));
 460                 return -EINVAL;
 461         }
 462         pr_info("ANDD device: %x name: %s\n", andd->device_number,
 463                 andd->device_name);
 464
 465         return 0;
 466 }
 467
 468 #ifdef CONFIG_ACPI_NUMA
 469 static int dmar_parse_one_rhsa(struct acpi_dmar_header *header, void *arg)
 470 {
 471         struct acpi_dmar_rhsa *rhsa;
 472         struct dmar_drhd_unit *drhd;
 473
 474         rhsa = (struct acpi_dmar_rhsa *)header;
 475         for_each_drhd_unit(drhd) {
 476                 if (drhd->reg_base_addr == rhsa->base_address) {
 477                         int node = acpi_map_pxm_to_node(rhsa->proximity_domain);
 478
 479                         if (!node_online(node))
 480                                 node = -1;
 481                         drhd->iommu->node = node;
 482                         return 0;
 483                 }
 484         }
 485         WARN_TAINT(
 486                 1, TAINT_FIRMWARE_WORKAROUND,
 487                 "Your BIOS is broken; RHSA refers to non-existent DMAR unit at %llx\n"
 488                 "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
 489                 drhd->reg_base_addr,
 490                 dmi_get_system_info(DMI_BIOS_VENDOR),
 491                 dmi_get_system_info(DMI_BIOS_VERSION),
 492                 dmi_get_system_info(DMI_PRODUCT_VERSION));
 493
 494         return 0;
 495 }
 496 #else
 497 #define dmar_parse_one_rhsa             dmar_res_noop
 498 #endif
 499
 500 static void
 501 dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
 502 {
 503         struct acpi_dmar_hardware_unit *drhd;
 504         struct acpi_dmar_reserved_memory *rmrr;
 505         struct acpi_dmar_atsr *atsr;
 506         struct acpi_dmar_rhsa *rhsa;
 507
 508         switch (header->type) {
 509         case ACPI_DMAR_TYPE_HARDWARE_UNIT:
 510                 drhd = container_of(header, struct acpi_dmar_hardware_unit,
 511                                     header);
 512                 pr_info("DRHD base: %#016Lx flags: %#x\n",
 513                         (unsigned long long)drhd->address, drhd->flags);
 514                 break;
 515         case ACPI_DMAR_TYPE_RESERVED_MEMORY:
 516                 rmrr = container_of(header, struct acpi_dmar_reserved_memory,
 517                                     header);
 518                 pr_info("RMRR base: %#016Lx end: %#016Lx\n",
 519                         (unsigned long long)rmrr->base_address,
 520                         (unsigned long long)rmrr->end_address);
 521                 break;
 522         case ACPI_DMAR_TYPE_ROOT_ATS:
 523                 atsr = container_of(header, struct acpi_dmar_atsr, header);
 524                 pr_info("ATSR flags: %#x\n", atsr->flags);
 525                 break;
 526         case ACPI_DMAR_TYPE_HARDWARE_AFFINITY:
 527                 rhsa = container_of(header, struct acpi_dmar_rhsa, header);
 528                 pr_info("RHSA base: %#016Lx proximity domain: %#x\n",
 529                        (unsigned long long)rhsa->base_address,
 530                        rhsa->proximity_domain);
 531                 break;
 532         case ACPI_DMAR_TYPE_NAMESPACE:
 533                 /* We don't print this here because we need to sanity-check
 534                    it first. So print it in dmar_parse_one_andd() instead. */
 535                 break;
 536         }
 537 }
 538
 539 /**
 540  * dmar_table_detect - checks to see if the platform supports DMAR devices
 541  */
 542 static int __init dmar_table_detect(void)
 543 {
 544         acpi_status status = AE_OK;
 545
 546         /* if we could find DMAR table, then there are DMAR devices */
 547         status = acpi_get_table(ACPI_SIG_DMAR, 0, &dmar_tbl);
 548
 549         if (ACPI_SUCCESS(status) && !dmar_tbl) {
 550                 pr_warn("Unable to map DMAR\n");
 551                 status = AE_NOT_FOUND;
 552         }
 553
 554         return ACPI_SUCCESS(status) ? 0 : -ENOENT;
 555 }
 556
 557 static int dmar_walk_remapping_entries(struct acpi_dmar_header *start,
 558                                        size_t len, struct dmar_res_callback *cb)
 559 {
 560         struct acpi_dmar_header *iter, *next;
 561         struct acpi_dmar_header *end = ((void *)start) + len;
 562
 563         for (iter = start; iter < end; iter = next) {
 564                 next = (void *)iter + iter->length;
 565                 if (iter->length == 0) {
 566                         /* Avoid looping forever on bad ACPI tables */
 567                         pr_debug(FW_BUG "Invalid 0-length structure\n");
 568                         break;
 569                 } else if (next > end) {
 570                         /* Avoid passing table end */
 571                         pr_warn(FW_BUG "Record passes table end\n");
 572                         return -EINVAL;
 573                 }
 574
 575                 if (cb->print_entry)
 576                         dmar_table_print_dmar_entry(iter);
 577
 578                 if (iter->type >= ACPI_DMAR_TYPE_RESERVED) {
 579                         /* continue for forward compatibility */
 580                         pr_debug("Unknown DMAR structure type %d\n",
 581                                  iter->type);
 582                 } else if (cb->cb[iter->type]) {
 583                         int ret;
 584
 585                         ret = cb->cb[iter->type](iter, cb->arg[iter->type]);
 586                         if (ret)
 587                                 return ret;
 588                 } else if (!cb->ignore_unhandled) {
 589                         pr_warn("No handler for DMAR structure type %d\n",
 590                                 iter->type);
 591                         return -EINVAL;
 592                 }
 593         }
 594
 595         return 0;
 596 }
 597
 598 static inline int dmar_walk_dmar_table(struct acpi_table_dmar *dmar,
 599                                        struct dmar_res_callback *cb)
 600 {
 601         return dmar_walk_remapping_entries((void *)(dmar + 1),
 602                         dmar->header.length - sizeof(*dmar), cb);
 603 }
 604
 605 /**
 606  * parse_dmar_table - parses the DMA reporting table
 607  */
 608 static int __init
 609 parse_dmar_table(void)
 610 {
 611         struct acpi_table_dmar *dmar;
 612         int drhd_count = 0;
 613         int ret;
 614         struct dmar_res_callback cb = {
 615                 .print_entry = true,
 616                 .ignore_unhandled = true,
 617                 .arg[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &drhd_count,
 618                 .cb[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &dmar_parse_one_drhd,
 619                 .cb[ACPI_DMAR_TYPE_RESERVED_MEMORY] = &dmar_parse_one_rmrr,
 620                 .cb[ACPI_DMAR_TYPE_ROOT_ATS] = &dmar_parse_one_atsr,
 621                 .cb[ACPI_DMAR_TYPE_HARDWARE_AFFINITY] = &dmar_parse_one_rhsa,
 622                 .cb[ACPI_DMAR_TYPE_NAMESPACE] = &dmar_parse_one_andd,
 623         };
 624
 625         /*
 626          * Do it again, earlier dmar_tbl mapping could be mapped with
 627          * fixed map.
 628          */
 629         dmar_table_detect();
 630
 631         /*
 632          * ACPI tables may not be DMA protected by tboot, so use DMAR copy
 633          * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
 634          */
 635         dmar_tbl = tboot_get_dmar_table(dmar_tbl);
 636
 637         dmar = (struct acpi_table_dmar *)dmar_tbl;
 638         if (!dmar)
 639                 return -ENODEV;
 640
 641         if (dmar->width < PAGE_SHIFT - 1) {
 642                 pr_warn("Invalid DMAR haw\n");
 643                 return -EINVAL;
 644         }
 645
 646         pr_info("Host address width %d\n", dmar->width + 1);
 647         ret = dmar_walk_dmar_table(dmar, &cb);
 648         if (ret == 0 && drhd_count == 0)
 649                 pr_warn(FW_BUG "No DRHD structure found in DMAR table\n");
 650
 651         return ret;
 652 }
 653
 654 static int dmar_pci_device_match(struct dmar_dev_scope devices[],
 655                                  int cnt, struct pci_dev *dev)
 656 {
 657         int index;
 658         struct device *tmp;
 659
 660         while (dev) {
 661                 for_each_active_dev_scope(devices, cnt, index, tmp)
 662                         if (dev_is_pci(tmp) && dev == to_pci_dev(tmp))
 663                                 return 1;
 664
 665                 /* Check our parent */
 666                 dev = dev->bus->self;
 667         }
 668
 669         return 0;
 670 }
 671
 672 struct dmar_drhd_unit *
 673 dmar_find_matched_drhd_unit(struct pci_dev *dev)
 674 {
 675         struct dmar_drhd_unit *dmaru;
 676         struct acpi_dmar_hardware_unit *drhd;
 677
 678         dev = pci_physfn(dev);
 679
 680         rcu_read_lock();
 681         for_each_drhd_unit(dmaru) {
 682                 drhd = container_of(dmaru->hdr,
 683                                     struct acpi_dmar_hardware_unit,
 684                                     header);
 685
 686                 if (dmaru->include_all &&
 687                     drhd->segment == pci_domain_nr(dev->bus))
 688                         goto out;
 689
 690                 if (dmar_pci_device_match(dmaru->devices,
 691                                           dmaru->devices_cnt, dev))
 692                         goto out;
 693         }
 694         dmaru = NULL;
 695 out:
 696         rcu_read_unlock();
 697
 698         return dmaru;
 699 }
 700
 701 static void __init dmar_acpi_insert_dev_scope(u8 device_number,
 702                                               struct acpi_device *adev)
 703 {
 704         struct dmar_drhd_unit *dmaru;
 705         struct acpi_dmar_hardware_unit *drhd;
 706         struct acpi_dmar_device_scope *scope;
 707         struct device *tmp;
 708         int i;
 709         struct acpi_dmar_pci_path *path;
 710
 711         for_each_drhd_unit(dmaru) {
 712                 drhd = container_of(dmaru->hdr,
 713                                     struct acpi_dmar_hardware_unit,
 714                                     header);
 715
 716                 for (scope = (void *)(drhd + 1);
 717                      (unsigned long)scope < ((unsigned long)drhd) + drhd->header.length;
 718                      scope = ((void *)scope) + scope->length) {
 719                         if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_NAMESPACE)
 720                                 continue;
 721                         if (scope->enumeration_id != device_number)
 722                                 continue;
 723
 724                         path = (void *)(scope + 1);
 725                         pr_info("ACPI device \"%s\" under DMAR at %llx as %02x:%02x.%d\n",
 726                                 dev_name(&adev->dev), dmaru->reg_base_addr,
 727                                 scope->bus, path->device, path->function);
 728                         for_each_dev_scope(dmaru->devices, dmaru->devices_cnt, i, tmp)
 729                                 if (tmp == NULL) {
 730                                         dmaru->devices[i].bus = scope->bus;
 731                                         dmaru->devices[i].devfn = PCI_DEVFN(path->device,
 732                                                                             path->function);
 733                                         rcu_assign_pointer(dmaru->devices[i].dev,
 734                                                            get_device(&adev->dev));
 735                                         return;
 736                                 }
 737                         BUG_ON(i >= dmaru->devices_cnt);
 738                 }
 739         }
 740         pr_warn("No IOMMU scope found for ANDD enumeration ID %d (%s)\n",
 741                 device_number, dev_name(&adev->dev));
 742 }
 743
 744 static int __init dmar_acpi_dev_scope_init(void)
 745 {
 746         struct acpi_dmar_andd *andd;
 747
 748         if (dmar_tbl == NULL)
 749                 return -ENODEV;
 750
 751         for (andd = (void *)dmar_tbl + sizeof(struct acpi_table_dmar);
 752              ((unsigned long)andd) < ((unsigned long)dmar_tbl) + dmar_tbl->length;
 753              andd = ((void *)andd) + andd->header.length) {
 754                 if (andd->header.type == ACPI_DMAR_TYPE_NAMESPACE) {
 755                         acpi_handle h;
 756                         struct acpi_device *adev;
 757
 758                         if (!ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT,
 759                                                           andd->device_name,
 760                                                           &h))) {
 761                                 pr_err("Failed to find handle for ACPI object %s\n",
 762                                        andd->device_name);
 763                                 continue;
 764                         }
 765                         if (acpi_bus_get_device(h, &adev)) {
 766                                 pr_err("Failed to get device for ACPI object %s\n",
 767                                        andd->device_name);
 768                                 continue;
 769                         }
 770                         dmar_acpi_insert_dev_scope(andd->device_number, adev);
 771                 }
 772         }
 773         return 0;
 774 }
 775
 776 int __init dmar_dev_scope_init(void)
 777 {
 778         struct pci_dev *dev = NULL;
 779         struct dmar_pci_notify_info *info;
 780
 781         if (dmar_dev_scope_status != 1)
 782                 return dmar_dev_scope_status;
 783
 784         if (list_empty(&dmar_drhd_units)) {
 785                 dmar_dev_scope_status = -ENODEV;
 786         } else {
 787                 dmar_dev_scope_status = 0;
 788
 789                 dmar_acpi_dev_scope_init();
 790
 791                 for_each_pci_dev(dev) {
 792                         if (dev->is_virtfn)
 793                                 continue;
 794
 795                         info = dmar_alloc_pci_notify_info(dev,
 796                                         BUS_NOTIFY_ADD_DEVICE);
 797                         if (!info) {
 798                                 return dmar_dev_scope_status;
 799                         } else {
 800                                 dmar_pci_bus_add_dev(info);
 801                                 dmar_free_pci_notify_info(info);
 802                         }
 803                 }
 804         }
 805
 806         return dmar_dev_scope_status;
 807 }
 808
 809 void dmar_register_bus_notifier(void)
 810 {
 811         bus_register_notifier(&pci_bus_type, &dmar_pci_bus_nb);
 812 }
 813
 814
 815 int __init dmar_table_init(void)
 816 {
 817         static int dmar_table_initialized;
 818         int ret;
 819
 820         if (dmar_table_initialized == 0) {
 821                 ret = parse_dmar_table();
 822                 if (ret < 0) {
 823                         if (ret != -ENODEV)
 824                                 pr_info("Parse DMAR table failure.\n");
 825                 } else  if (list_empty(&dmar_drhd_units)) {
 826                         pr_info("No DMAR devices found\n");
 827                         ret = -ENODEV;
 828                 }
 829
 830                 if (ret < 0)
 831                         dmar_table_initialized = ret;
 832                 else
 833                         dmar_table_initialized = 1;
 834         }
 835
 836         return dmar_table_initialized < 0 ? dmar_table_initialized : 0;
 837 }
 838
 839 static void warn_invalid_dmar(u64 addr, const char *message)
 840 {
 841         WARN_TAINT_ONCE(
 842                 1, TAINT_FIRMWARE_WORKAROUND,
 843                 "Your BIOS is broken; DMAR reported at address %llx%s!\n"
 844                 "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
 845                 addr, message,
 846                 dmi_get_system_info(DMI_BIOS_VENDOR),
 847                 dmi_get_system_info(DMI_BIOS_VERSION),
 848                 dmi_get_system_info(DMI_PRODUCT_VERSION));
 849 }
 850
 851 static int __ref
 852 dmar_validate_one_drhd(struct acpi_dmar_header *entry, void *arg)
 853 {
 854         struct acpi_dmar_hardware_unit *drhd;
 855         void __iomem *addr;
 856         u64 cap, ecap;
 857
 858         drhd = (void *)entry;
 859         if (!drhd->address) {
 860                 warn_invalid_dmar(0, "");
 861                 return -EINVAL;
 862         }
 863
 864         if (arg)
 865                 addr = ioremap(drhd->address, VTD_PAGE_SIZE);
 866         else
 867                 addr = early_ioremap(drhd->address, VTD_PAGE_SIZE);
 868         if (!addr) {
 869                 pr_warn("Can't validate DRHD address: %llx\n", drhd->address);
 870                 return -EINVAL;
 871         }
 872
 873         cap = dmar_readq(addr + DMAR_CAP_REG);
 874         ecap = dmar_readq(addr + DMAR_ECAP_REG);
 875
 876         if (arg)
 877                 iounmap(addr);
 878         else
 879                 early_iounmap(addr, VTD_PAGE_SIZE);
 880
 881         if (cap == (uint64_t)-1 && ecap == (uint64_t)-1) {
 882                 warn_invalid_dmar(drhd->address, " returns all ones");
 883                 return -EINVAL;
 884         }
 885
 886         return 0;
 887 }
 888
 889 int __init detect_intel_iommu(void)
 890 {
 891         int ret;
 892         struct dmar_res_callback validate_drhd_cb = {
 893                 .cb[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &dmar_validate_one_drhd,
 894                 .ignore_unhandled = true,
 895         };
 896
 897         down_write(&dmar_global_lock);
 898         ret = dmar_table_detect();
 899         if (!ret)
 900                 ret = dmar_walk_dmar_table((struct acpi_table_dmar *)dmar_tbl,
 901                                            &validate_drhd_cb);
 902         if (!ret && !no_iommu && !iommu_detected && !dmar_disabled) {
 903                 iommu_detected = 1;
 904                 /* Make sure ACS will be enabled */
 905                 pci_request_acs();
 906         }
 907
 908 #ifdef CONFIG_X86
 909         if (!ret)
 910                 x86_init.iommu.iommu_init = intel_iommu_init;
 911 #endif
 912
 913         if (dmar_tbl) {
 914                 acpi_put_table(dmar_tbl);
 915                 dmar_tbl = NULL;
 916         }
 917         up_write(&dmar_global_lock);
 918
 919         return ret ? ret : 1;
 920 }
 921
 922 static void unmap_iommu(struct intel_iommu *iommu)
 923 {
 924         iounmap(iommu->reg);
 925         release_mem_region(iommu->reg_phys, iommu->reg_size);
 926 }
 927
 928 /**
 929  * map_iommu: map the iommu's registers
 930  * @iommu: the iommu to map
 931  * @phys_addr: the physical address of the base resgister
 932  *
 933  * Memory map the iommu's registers.  Start w/ a single page, and
 934  * possibly expand if that turns out to be insufficent.
 935  */
 936 static int map_iommu(struct intel_iommu *iommu, u64 phys_addr)
 937 {
 938         int map_size, err=0;
 939
 940         iommu->reg_phys = phys_addr;
 941         iommu->reg_size = VTD_PAGE_SIZE;
 942
 943         if (!request_mem_region(iommu->reg_phys, iommu->reg_size, iommu->name)) {
 944                 pr_err("Can't reserve memory\n");
 945                 err = -EBUSY;
 946                 goto out;
 947         }
 948
 949         iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
 950         if (!iommu->reg) {
 951                 pr_err("Can't map the region\n");
 952                 err = -ENOMEM;
 953                 goto release;
 954         }
 955
 956         iommu->cap = dmar_readq(iommu->reg + DMAR_CAP_REG);
 957         iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG);
 958
 959         if (iommu->cap == (uint64_t)-1 && iommu->ecap == (uint64_t)-1) {
 960                 err = -EINVAL;
 961                 warn_invalid_dmar(phys_addr, " returns all ones");
 962                 goto unmap;
 963         }
 964
 965         /* the registers might be more than one page */
 966         map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),
 967                          cap_max_fault_reg_offset(iommu->cap));
 968         map_size = VTD_PAGE_ALIGN(map_size);
 969         if (map_size > iommu->reg_size) {
 970                 iounmap(iommu->reg);
 971                 release_mem_region(iommu->reg_phys, iommu->reg_size);
 972                 iommu->reg_size = map_size;
 973                 if (!request_mem_region(iommu->reg_phys, iommu->reg_size,
 974                                         iommu->name)) {
 975                         pr_err("Can't reserve memory\n");
 976                         err = -EBUSY;
 977                         goto out;
 978                 }
 979                 iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
 980                 if (!iommu->reg) {
 981                         pr_err("Can't map the region\n");
 982                         err = -ENOMEM;
 983                         goto release;
 984                 }
 985         }
 986         err = 0;
 987         goto out;
 988
 989 unmap:
 990         iounmap(iommu->reg);
 991 release:
 992         release_mem_region(iommu->reg_phys, iommu->reg_size);
 993 out:
 994         return err;
 995 }
 996
 997 static int dmar_alloc_seq_id(struct intel_iommu *iommu)
 998 {
 999         iommu->seq_id = find_first_zero_bit(dmar_seq_ids,
1000                                             DMAR_UNITS_SUPPORTED);
1001         if (iommu->seq_id >= DMAR_UNITS_SUPPORTED) {
1002                 iommu->seq_id = -1;
1003         } else {
1004                 set_bit(iommu->seq_id, dmar_seq_ids);
1005                 sprintf(iommu->name, "dmar%d", iommu->seq_id);
1006         }
1007
1008         return iommu->seq_id;
1009 }
1010
1011 static void dmar_free_seq_id(struct intel_iommu *iommu)
1012 {
1013         if (iommu->seq_id >= 0) {
1014                 clear_bit(iommu->seq_id, dmar_seq_ids);
1015                 iommu->seq_id = -1;
1016         }
1017 }
1018
1019 static int alloc_iommu(struct dmar_drhd_unit *drhd)
1020 {
1021         struct intel_iommu *iommu;
1022         u32 ver, sts;
1023         int agaw = 0;
1024         int msagaw = 0;
1025         int err;
1026
1027         if (!drhd->reg_base_addr) {
1028                 warn_invalid_dmar(0, "");
1029                 return -EINVAL;
1030         }
1031
1032         iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
1033         if (!iommu)
1034                 return -ENOMEM;
1035
1036         if (dmar_alloc_seq_id(iommu) < 0) {
1037                 pr_err("Failed to allocate seq_id\n");
1038                 err = -ENOSPC;
1039                 goto error;
1040         }
1041
1042         err = map_iommu(iommu, drhd->reg_base_addr);
1043         if (err) {
1044                 pr_err("Failed to map %s\n", iommu->name);
1045                 goto error_free_seq_id;
1046         }
1047
1048         err = -EINVAL;
1049         agaw = iommu_calculate_agaw(iommu);
1050         if (agaw < 0) {
1051                 pr_err("Cannot get a valid agaw for iommu (seq_id = %d)\n",
1052                         iommu->seq_id);
1053                 goto err_unmap;
1054         }
1055         msagaw = iommu_calculate_max_sagaw(iommu);
1056         if (msagaw < 0) {
1057                 pr_err("Cannot get a valid max agaw for iommu (seq_id = %d)\n",
1058                         iommu->seq_id);
1059                 goto err_unmap;
1060         }
1061         iommu->agaw = agaw;
1062         iommu->msagaw = msagaw;
1063         iommu->segment = drhd->segment;
1064
1065         iommu->node = -1;
1066
1067         ver = readl(iommu->reg + DMAR_VER_REG);
1068         pr_info("%s: reg_base_addr %llx ver %d:%d cap %llx ecap %llx\n",
1069                 iommu->name,
1070                 (unsigned long long)drhd->reg_base_addr,
1071                 DMAR_VER_MAJOR(ver), DMAR_VER_MINOR(ver),
1072                 (unsigned long long)iommu->cap,
1073                 (unsigned long long)iommu->ecap);
1074
1075         /* Reflect status in gcmd */
1076         sts = readl(iommu->reg + DMAR_GSTS_REG);
1077         if (sts & DMA_GSTS_IRES)
1078                 iommu->gcmd |= DMA_GCMD_IRE;
1079         if (sts & DMA_GSTS_TES)
1080                 iommu->gcmd |= DMA_GCMD_TE;
1081         if (sts & DMA_GSTS_QIES)
1082                 iommu->gcmd |= DMA_GCMD_QIE;
1083
1084         raw_spin_lock_init(&iommu->register_lock);
1085
1086         if (intel_iommu_enabled) {
1087                 err = iommu_device_sysfs_add(&iommu->iommu, NULL,
1088                                              intel_iommu_groups,
1089                                              "%s", iommu->name);
1090                 if (err)
1091                         goto err_unmap;
1092
1093                 iommu_device_set_ops(&iommu->iommu, &intel_iommu_ops);
1094
1095                 err = iommu_device_register(&iommu->iommu);
1096                 if (err)
1097                         goto err_unmap;
1098         }
1099
1100         drhd->iommu = iommu;
1101
1102         return 0;
1103
1104 err_unmap:
1105         unmap_iommu(iommu);
1106 error_free_seq_id:
1107         dmar_free_seq_id(iommu);
1108 error:
1109         kfree(iommu);
1110         return err;
1111 }
1112
1113 static void free_iommu(struct intel_iommu *iommu)
1114 {
1115         if (intel_iommu_enabled) {
1116                 iommu_device_unregister(&iommu->iommu);
1117                 iommu_device_sysfs_remove(&iommu->iommu);
1118         }
1119
1120         if (iommu->irq) {
1121                 if (iommu->pr_irq) {
1122                         free_irq(iommu->pr_irq, iommu);
1123                         dmar_free_hwirq(iommu->pr_irq);
1124                         iommu->pr_irq = 0;
1125                 }
1126                 free_irq(iommu->irq, iommu);
1127                 dmar_free_hwirq(iommu->irq);
1128                 iommu->irq = 0;
1129         }
1130
1131         if (iommu->qi) {
1132                 free_page((unsigned long)iommu->qi->desc);
1133                 kfree(iommu->qi->desc_status);
1134                 kfree(iommu->qi);
1135         }
1136
1137         if (iommu->reg)
1138                 unmap_iommu(iommu);
1139
1140         dmar_free_seq_id(iommu);
1141         kfree(iommu);
1142 }
1143
1144 /*
1145  * Reclaim all the submitted descriptors which have completed its work.
1146  */
1147 static inline void reclaim_free_desc(struct q_inval *qi)
1148 {
1149         while (qi->desc_status[qi->free_tail] == QI_DONE ||
1150                qi->desc_status[qi->free_tail] == QI_ABORT) {
1151                 qi->desc_status[qi->free_tail] = QI_FREE;
1152                 qi->free_tail = (qi->free_tail + 1) % QI_LENGTH;
1153                 qi->free_cnt++;
1154         }
1155 }
1156
1157 static int qi_check_fault(struct intel_iommu *iommu, int index)
1158 {
1159         u32 fault;
1160         int head, tail;
1161         struct q_inval *qi = iommu->qi;
1162         int wait_index = (index + 1) % QI_LENGTH;
1163
1164         if (qi->desc_status[wait_index] == QI_ABORT)
1165                 return -EAGAIN;
1166
1167         fault = readl(iommu->reg + DMAR_FSTS_REG);
1168
1169         /*
1170          * If IQE happens, the head points to the descriptor associated
1171          * with the error. No new descriptors are fetched until the IQE
1172          * is cleared.
1173          */
1174         if (fault & DMA_FSTS_IQE) {
1175                 head = readl(iommu->reg + DMAR_IQH_REG);
1176                 if ((head >> DMAR_IQ_SHIFT) == index) {
1177                         pr_err("VT-d detected invalid descriptor: "
1178                                 "low=%llx, high=%llx\n",
1179                                 (unsigned long long)qi->desc[index].low,
1180                                 (unsigned long long)qi->desc[index].high);
1181                         memcpy(&qi->desc[index], &qi->desc[wait_index],
1182                                         sizeof(struct qi_desc));
1183                         writel(DMA_FSTS_IQE, iommu->reg + DMAR_FSTS_REG);
1184                         return -EINVAL;
1185                 }
1186         }
1187
1188         /*
1189          * If ITE happens, all pending wait_desc commands are aborted.
1190          * No new descriptors are fetched until the ITE is cleared.
1191          */
1192         if (fault & DMA_FSTS_ITE) {
1193                 head = readl(iommu->reg + DMAR_IQH_REG);
1194                 head = ((head >> DMAR_IQ_SHIFT) - 1 + QI_LENGTH) % QI_LENGTH;
1195                 head |= 1;
1196                 tail = readl(iommu->reg + DMAR_IQT_REG);
1197                 tail = ((tail >> DMAR_IQ_SHIFT) - 1 + QI_LENGTH) % QI_LENGTH;
1198
1199                 writel(DMA_FSTS_ITE, iommu->reg + DMAR_FSTS_REG);
1200
1201                 do {
1202                         if (qi->desc_status[head] == QI_IN_USE)
1203                                 qi->desc_status[head] = QI_ABORT;
1204                         head = (head - 2 + QI_LENGTH) % QI_LENGTH;
1205                 } while (head != tail);
1206
1207                 if (qi->desc_status[wait_index] == QI_ABORT)
1208                         return -EAGAIN;
1209         }
1210
1211         if (fault & DMA_FSTS_ICE)
1212                 writel(DMA_FSTS_ICE, iommu->reg + DMAR_FSTS_REG);
1213
1214         return 0;
1215 }
1216
1217 /*
1218  * Submit the queued invalidation descriptor to the remapping
1219  * hardware unit and wait for its completion.
1220  */
1221 int qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu)
1222 {
1223         int rc;
1224         struct q_inval *qi = iommu->qi;
1225         struct qi_desc *hw, wait_desc;
1226         int wait_index, index;
1227         unsigned long flags;
1228
1229         if (!qi)
1230                 return 0;
1231
1232         hw = qi->desc;
1233
1234 restart:
1235         rc = 0;
1236
1237         raw_spin_lock_irqsave(&qi->q_lock, flags);
1238         while (qi->free_cnt < 3) {
1239                 raw_spin_unlock_irqrestore(&qi->q_lock, flags);
1240                 cpu_relax();
1241                 raw_spin_lock_irqsave(&qi->q_lock, flags);
1242         }
1243
1244         index = qi->free_head;
1245         wait_index = (index + 1) % QI_LENGTH;
1246
1247         qi->desc_status[index] = qi->desc_status[wait_index] = QI_IN_USE;
1248
1249         hw[index] = *desc;
1250
1251         wait_desc.low = QI_IWD_STATUS_DATA(QI_DONE) |
1252                         QI_IWD_STATUS_WRITE | QI_IWD_TYPE;
1253         wait_desc.high = virt_to_phys(&qi->desc_status[wait_index]);
1254
1255         hw[wait_index] = wait_desc;
1256
1257         qi->free_head = (qi->free_head + 2) % QI_LENGTH;
1258         qi->free_cnt -= 2;
1259
1260         /*
1261          * update the HW tail register indicating the presence of
1262          * new descriptors.
1263          */
1264         writel(qi->free_head << DMAR_IQ_SHIFT, iommu->reg + DMAR_IQT_REG);
1265
1266         while (qi->desc_status[wait_index] != QI_DONE) {
1267                 /*
1268                  * We will leave the interrupts disabled, to prevent interrupt
1269                  * context to queue another cmd while a cmd is already submitted
1270                  * and waiting for completion on this cpu. This is to avoid
1271                  * a deadlock where the interrupt context can wait indefinitely
1272                  * for free slots in the queue.
1273                  */
1274                 rc = qi_check_fault(iommu, index);
1275                 if (rc)
1276                         break;
1277
1278                 raw_spin_unlock(&qi->q_lock);
1279                 cpu_relax();
1280                 raw_spin_lock(&qi->q_lock);
1281         }
1282
1283         qi->desc_status[index] = QI_DONE;
1284
1285         reclaim_free_desc(qi);
1286         raw_spin_unlock_irqrestore(&qi->q_lock, flags);
1287
1288         if (rc == -EAGAIN)
1289                 goto restart;
1290
1291         return rc;
1292 }
1293
1294 /*
1295  * Flush the global interrupt entry cache.
1296  */
1297 void qi_global_iec(struct intel_iommu *iommu)
1298 {
1299         struct qi_desc desc;
1300
1301         desc.low = QI_IEC_TYPE;
1302         desc.high = 0;
1303
1304         /* should never fail */
1305         qi_submit_sync(&desc, iommu);
1306 }
1307
1308 void qi_flush_context(struct intel_iommu *iommu, u16 did, u16 sid, u8 fm,
1309                       u64 type)
1310 {
1311         struct qi_desc desc;
1312
1313         desc.low = QI_CC_FM(fm) | QI_CC_SID(sid) | QI_CC_DID(did)
1314                         | QI_CC_GRAN(type) | QI_CC_TYPE;
1315         desc.high = 0;
1316
1317         qi_submit_sync(&desc, iommu);
1318 }
1319
1320 void qi_flush_iotlb(struct intel_iommu *iommu, u16 did, u64 addr,
1321                     unsigned int size_order, u64 type)
1322 {
1323         u8 dw = 0, dr = 0;
1324
1325         struct qi_desc desc;
1326         int ih = 0;
1327
1328         if (cap_write_drain(iommu->cap))
1329                 dw = 1;
1330
1331         if (cap_read_drain(iommu->cap))
1332                 dr = 1;
1333
1334         desc.low = QI_IOTLB_DID(did) | QI_IOTLB_DR(dr) | QI_IOTLB_DW(dw)
1335                 | QI_IOTLB_GRAN(type) | QI_IOTLB_TYPE;
1336         desc.high = QI_IOTLB_ADDR(addr) | QI_IOTLB_IH(ih)
1337                 | QI_IOTLB_AM(size_order);
1338
1339         qi_submit_sync(&desc, iommu);
1340 }
1341
1342 void qi_flush_dev_iotlb(struct intel_iommu *iommu, u16 sid, u16 qdep,
1343                         u64 addr, unsigned mask)
1344 {
1345         struct qi_desc desc;
1346
1347         if (mask) {
1348                 BUG_ON(addr & ((1 << (VTD_PAGE_SHIFT + mask)) - 1));
1349                 addr |= (1ULL << (VTD_PAGE_SHIFT + mask - 1)) - 1;
1350                 desc.high = QI_DEV_IOTLB_ADDR(addr) | QI_DEV_IOTLB_SIZE;
1351         } else
1352                 desc.high = QI_DEV_IOTLB_ADDR(addr);
1353
1354         if (qdep >= QI_DEV_IOTLB_MAX_INVS)
1355                 qdep = 0;
1356
1357         desc.low = QI_DEV_IOTLB_SID(sid) | QI_DEV_IOTLB_QDEP(qdep) |
1358                    QI_DIOTLB_TYPE;
1359
1360         qi_submit_sync(&desc, iommu);
1361 }
1362
1363 /*
1364  * Disable Queued Invalidation interface.
1365  */
1366 void dmar_disable_qi(struct intel_iommu *iommu)
1367 {
1368         unsigned long flags;
1369         u32 sts;
1370         cycles_t start_time = get_cycles();
1371
1372         if (!ecap_qis(iommu->ecap))
1373                 return;
1374
1375         raw_spin_lock_irqsave(&iommu->register_lock, flags);
1376
1377         sts =  readl(iommu->reg + DMAR_GSTS_REG);
1378         if (!(sts & DMA_GSTS_QIES))
1379                 goto end;
1380
1381         /*
1382          * Give a chance to HW to complete the pending invalidation requests.
1383          */
1384         while ((readl(iommu->reg + DMAR_IQT_REG) !=
1385                 readl(iommu->reg + DMAR_IQH_REG)) &&
1386                 (DMAR_OPERATION_TIMEOUT > (get_cycles() - start_time)))
1387                 cpu_relax();
1388
1389         iommu->gcmd &= ~DMA_GCMD_QIE;
1390         writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
1391
1392         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl,
1393                       !(sts & DMA_GSTS_QIES), sts);
1394 end:
1395         raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
1396 }
1397
1398 /*
1399  * Enable queued invalidation.
1400  */
1401 static void __dmar_enable_qi(struct intel_iommu *iommu)
1402 {
1403         u32 sts;
1404         unsigned long flags;
1405         struct q_inval *qi = iommu->qi;
1406
1407         qi->free_head = qi->free_tail = 0;
1408         qi->free_cnt = QI_LENGTH;
1409
1410         raw_spin_lock_irqsave(&iommu->register_lock, flags);
1411
1412         /* write zero to the tail reg */
1413         writel(0, iommu->reg + DMAR_IQT_REG);
1414
1415         dmar_writeq(iommu->reg + DMAR_IQA_REG, virt_to_phys(qi->desc));
1416
1417         iommu->gcmd |= DMA_GCMD_QIE;
1418         writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
1419
1420         /* Make sure hardware complete it */
1421         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl, (sts & DMA_GSTS_QIES), sts);
1422
1423         raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
1424 }
1425
1426 /*
1427  * Enable Queued Invalidation interface. This is a must to support
1428  * interrupt-remapping. Also used by DMA-remapping, which replaces
1429  * register based IOTLB invalidation.
1430  */
1431 int dmar_enable_qi(struct intel_iommu *iommu)
1432 {
1433         struct q_inval *qi;
1434         struct page *desc_page;
1435
1436         if (!ecap_qis(iommu->ecap))
1437                 return -ENOENT;
1438
1439         /*
1440          * queued invalidation is already setup and enabled.
1441          */
1442         if (iommu->qi)
1443                 return 0;
1444
1445         iommu->qi = kmalloc(sizeof(*qi), GFP_ATOMIC);
1446         if (!iommu->qi)
1447                 return -ENOMEM;
1448
1449         qi = iommu->qi;
1450
1451
1452         desc_page = alloc_pages_node(iommu->node, GFP_ATOMIC | __GFP_ZERO, 0);
1453         if (!desc_page) {
1454                 kfree(qi);
1455                 iommu->qi = NULL;
1456                 return -ENOMEM;
1457         }
1458
1459         qi->desc = page_address(desc_page);
1460
1461         qi->desc_status = kzalloc(QI_LENGTH * sizeof(int), GFP_ATOMIC);
1462         if (!qi->desc_status) {
1463                 free_page((unsigned long) qi->desc);
1464                 kfree(qi);
1465                 iommu->qi = NULL;
1466                 return -ENOMEM;
1467         }
1468
1469         raw_spin_lock_init(&qi->q_lock);
1470
1471         __dmar_enable_qi(iommu);
1472
1473         return 0;
1474 }
1475
1476 /* iommu interrupt handling. Most stuff are MSI-like. */
1477
1478 enum faulttype {
1479         DMA_REMAP,
1480         INTR_REMAP,
1481         UNKNOWN,
1482 };
1483
1484 static const char *dma_remap_fault_reasons[] =
1485 {
1486         "Software",
1487         "Present bit in root entry is clear",
1488         "Present bit in context entry is clear",
1489         "Invalid context entry",
1490         "Access beyond MGAW",
1491         "PTE Write access is not set",
1492         "PTE Read access is not set",
1493         "Next page table ptr is invalid",
1494         "Root table address invalid",
1495         "Context table ptr is invalid",
1496         "non-zero reserved fields in RTP",
1497         "non-zero reserved fields in CTP",
1498         "non-zero reserved fields in PTE",
1499         "PCE for translation request specifies blocking",
1500 };
1501
1502 static const char *irq_remap_fault_reasons[] =
1503 {
1504         "Detected reserved fields in the decoded interrupt-remapped request",
1505         "Interrupt index exceeded the interrupt-remapping table size",
1506         "Present field in the IRTE entry is clear",
1507         "Error accessing interrupt-remapping table pointed by IRTA_REG",
1508         "Detected reserved fields in the IRTE entry",
1509         "Blocked a compatibility format interrupt request",
1510         "Blocked an interrupt request due to source-id verification failure",
1511 };
1512
1513 static const char *dmar_get_fault_reason(u8 fault_reason, int *fault_type)
1514 {
1515         if (fault_reason >= 0x20 && (fault_reason - 0x20 <
1516                                         ARRAY_SIZE(irq_remap_fault_reasons))) {
1517                 *fault_type = INTR_REMAP;
1518                 return irq_remap_fault_reasons[fault_reason - 0x20];
1519         } else if (fault_reason < ARRAY_SIZE(dma_remap_fault_reasons)) {
1520                 *fault_type = DMA_REMAP;
1521                 return dma_remap_fault_reasons[fault_reason];
1522         } else {
1523                 *fault_type = UNKNOWN;
1524                 return "Unknown";
1525         }
1526 }
1527
1528
1529 static inline int dmar_msi_reg(struct intel_iommu *iommu, int irq)
1530 {
1531         if (iommu->irq == irq)
1532                 return DMAR_FECTL_REG;
1533         else if (iommu->pr_irq == irq)
1534                 return DMAR_PECTL_REG;
1535         else
1536                 BUG();
1537 }
1538
1539 void dmar_msi_unmask(struct irq_data *data)
1540 {
1541         struct intel_iommu *iommu = irq_data_get_irq_handler_data(data);
1542         int reg = dmar_msi_reg(iommu, data->irq);
1543         unsigned long flag;
1544
1545         /* unmask it */
1546         raw_spin_lock_irqsave(&iommu->register_lock, flag);
1547         writel(0, iommu->reg + reg);
1548         /* Read a reg to force flush the post write */
1549         readl(iommu->reg + reg);
1550         raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1551 }
1552
1553 void dmar_msi_mask(struct irq_data *data)
1554 {
1555         struct intel_iommu *iommu = irq_data_get_irq_handler_data(data);
1556         int reg = dmar_msi_reg(iommu, data->irq);
1557         unsigned long flag;
1558
1559         /* mask it */
1560         raw_spin_lock_irqsave(&iommu->register_lock, flag);
1561         writel(DMA_FECTL_IM, iommu->reg + reg);
1562         /* Read a reg to force flush the post write */
1563         readl(iommu->reg + reg);
1564         raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1565 }
1566
1567 void dmar_msi_write(int irq, struct msi_msg *msg)
1568 {
1569         struct intel_iommu *iommu = irq_get_handler_data(irq);
1570         int reg = dmar_msi_reg(iommu, irq);
1571         unsigned long flag;
1572
1573         raw_spin_lock_irqsave(&iommu->register_lock, flag);
1574         writel(msg->data, iommu->reg + reg + 4);
1575         writel(msg->address_lo, iommu->reg + reg + 8);
1576         writel(msg->address_hi, iommu->reg + reg + 12);
1577         raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1578 }
1579
1580 void dmar_msi_read(int irq, struct msi_msg *msg)
1581 {
1582         struct intel_iommu *iommu = irq_get_handler_data(irq);
1583         int reg = dmar_msi_reg(iommu, irq);
1584         unsigned long flag;
1585
1586         raw_spin_lock_irqsave(&iommu->register_lock, flag);
1587         msg->data = readl(iommu->reg + reg + 4);
1588         msg->address_lo = readl(iommu->reg + reg + 8);
1589         msg->address_hi = readl(iommu->reg + reg + 12);
1590         raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1591 }
1592
1593 static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
1594                 u8 fault_reason, u16 source_id, unsigned long long addr)
1595 {
1596         const char *reason;
1597         int fault_type;
1598
1599         reason = dmar_get_fault_reason(fault_reason, &fault_type);
1600
1601         if (fault_type == INTR_REMAP)
1602                 pr_err("[INTR-REMAP] Request device [%02x:%02x.%d] fault index %llx [fault reason %02d] %s\n",
1603                         source_id >> 8, PCI_SLOT(source_id & 0xFF),
1604                         PCI_FUNC(source_id & 0xFF), addr >> 48,
1605                         fault_reason, reason);
1606         else
1607                 pr_err("[%s] Request device [%02x:%02x.%d] fault addr %llx [fault reason %02d] %s\n",
1608                        type ? "DMA Read" : "DMA Write",
1609                        source_id >> 8, PCI_SLOT(source_id & 0xFF),
1610                        PCI_FUNC(source_id & 0xFF), addr, fault_reason, reason);
1611         return 0;
1612 }
1613
1614 #define PRIMARY_FAULT_REG_LEN (16)
1615 irqreturn_t dmar_fault(int irq, void *dev_id)
1616 {
1617         struct intel_iommu *iommu = dev_id;
1618         int reg, fault_index;
1619         u32 fault_status;
1620         unsigned long flag;
1621         bool ratelimited;
1622         static DEFINE_RATELIMIT_STATE(rs,
1623                                       DEFAULT_RATELIMIT_INTERVAL,
1624                                       DEFAULT_RATELIMIT_BURST);
1625
1626         /* Disable printing, simply clear the fault when ratelimited */
1627         ratelimited = !__ratelimit(&rs);
1628
1629         raw_spin_lock_irqsave(&iommu->register_lock, flag);
1630         fault_status = readl(iommu->reg + DMAR_FSTS_REG);
1631         if (fault_status && !ratelimited)
1632                 pr_err("DRHD: handling fault status reg %x\n", fault_status);
1633
1634         /* TBD: ignore advanced fault log currently */
1635         if (!(fault_status & DMA_FSTS_PPF))
1636                 goto unlock_exit;
1637
1638         fault_index = dma_fsts_fault_record_index(fault_status);
1639         reg = cap_fault_reg_offset(iommu->cap);
1640         while (1) {
1641                 u8 fault_reason;
1642                 u16 source_id;
1643                 u64 guest_addr;
1644                 int type;
1645                 u32 data;
1646
1647                 /* highest 32 bits */
1648                 data = readl(iommu->reg + reg +
1649                                 fault_index * PRIMARY_FAULT_REG_LEN + 12);
1650                 if (!(data & DMA_FRCD_F))
1651                         break;
1652
1653                 if (!ratelimited) {
1654                         fault_reason = dma_frcd_fault_reason(data);
1655                         type = dma_frcd_type(data);
1656
1657                         data = readl(iommu->reg + reg +
1658                                      fault_index * PRIMARY_FAULT_REG_LEN + 8);
1659                         source_id = dma_frcd_source_id(data);
1660
1661                         guest_addr = dmar_readq(iommu->reg + reg +
1662                                         fault_index * PRIMARY_FAULT_REG_LEN);
1663                         guest_addr = dma_frcd_page_addr(guest_addr);
1664                 }
1665
1666                 /* clear the fault */
1667                 writel(DMA_FRCD_F, iommu->reg + reg +
1668                         fault_index * PRIMARY_FAULT_REG_LEN + 12);
1669
1670                 raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1671
1672                 if (!ratelimited)
1673                         dmar_fault_do_one(iommu, type, fault_reason,
1674                                           source_id, guest_addr);
1675
1676                 fault_index++;
1677                 if (fault_index >= cap_num_fault_regs(iommu->cap))
1678                         fault_index = 0;
1679                 raw_spin_lock_irqsave(&iommu->register_lock, flag);
1680         }
1681
1682         writel(DMA_FSTS_PFO | DMA_FSTS_PPF | DMA_FSTS_PRO,
1683                iommu->reg + DMAR_FSTS_REG);
1684
1685 unlock_exit:
1686         raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1687         return IRQ_HANDLED;
1688 }
1689
1690 int dmar_set_interrupt(struct intel_iommu *iommu)
1691 {
1692         int irq, ret;
1693
1694         /*
1695          * Check if the fault interrupt is already initialized.
1696          */
1697         if (iommu->irq)
1698                 return 0;
1699
1700         irq = dmar_alloc_hwirq(iommu->seq_id, iommu->node, iommu);
1701         if (irq > 0) {
1702                 iommu->irq = irq;
1703         } else {
1704                 pr_err("No free IRQ vectors\n");
1705                 return -EINVAL;
1706         }
1707
1708         ret = request_irq(irq, dmar_fault, IRQF_NO_THREAD, iommu->name, iommu);
1709         if (ret)
1710                 pr_err("Can't request irq\n");
1711         return ret;
1712 }
1713
1714 int __init enable_drhd_fault_handling(void)
1715 {
1716         struct dmar_drhd_unit *drhd;
1717         struct intel_iommu *iommu;
1718
1719         /*
1720          * Enable fault control interrupt.
1721          */
1722         for_each_iommu(iommu, drhd) {
1723                 u32 fault_status;
1724                 int ret = dmar_set_interrupt(iommu);
1725
1726                 if (ret) {
1727                         pr_err("DRHD %Lx: failed to enable fault, interrupt, ret %d\n",
1728                                (unsigned long long)drhd->reg_base_addr, ret);
1729                         return -1;
1730                 }
1731
1732                 /*
1733                  * Clear any previous faults.
1734                  */
1735                 dmar_fault(iommu->irq, iommu);
1736                 fault_status = readl(iommu->reg + DMAR_FSTS_REG);
1737                 writel(fault_status, iommu->reg + DMAR_FSTS_REG);
1738         }
1739
1740         return 0;
1741 }
1742
1743 /*
1744  * Re-enable Queued Invalidation interface.
1745  */
1746 int dmar_reenable_qi(struct intel_iommu *iommu)
1747 {
1748         if (!ecap_qis(iommu->ecap))
1749                 return -ENOENT;
1750
1751         if (!iommu->qi)
1752                 return -ENOENT;
1753
1754         /*
1755          * First disable queued invalidation.
1756          */
1757         dmar_disable_qi(iommu);
1758         /*
1759          * Then enable queued invalidation again. Since there is no pending
1760          * invalidation requests now, it's safe to re-enable queued
1761          * invalidation.
1762          */
1763         __dmar_enable_qi(iommu);
1764
1765         return 0;
1766 }
1767
1768 /*
1769  * Check interrupt remapping support in DMAR table description.
1770  */
1771 int __init dmar_ir_support(void)
1772 {
1773         struct acpi_table_dmar *dmar;
1774         dmar = (struct acpi_table_dmar *)dmar_tbl;
1775         if (!dmar)
1776                 return 0;
1777         return dmar->flags & 0x1;
1778 }
1779
1780 /* Check whether DMAR units are in use */
1781 static inline bool dmar_in_use(void)
1782 {
1783         return irq_remapping_enabled || intel_iommu_enabled;
1784 }
1785
1786 static int __init dmar_free_unused_resources(void)
1787 {
1788         struct dmar_drhd_unit *dmaru, *dmaru_n;
1789
1790         if (dmar_in_use())
1791                 return 0;
1792
1793         if (dmar_dev_scope_status != 1 && !list_empty(&dmar_drhd_units))
1794                 bus_unregister_notifier(&pci_bus_type, &dmar_pci_bus_nb);
1795
1796         down_write(&dmar_global_lock);
1797         list_for_each_entry_safe(dmaru, dmaru_n, &dmar_drhd_units, list) {
1798                 list_del(&dmaru->list);
1799                 dmar_free_drhd(dmaru);
1800         }
1801         up_write(&dmar_global_lock);
1802
1803         return 0;
1804 }
1805
1806 late_initcall(dmar_free_unused_resources);
1807 IOMMU_INIT_POST(detect_intel_iommu);
1808
1809 /*
1810  * DMAR Hotplug Support
1811  * For more details, please refer to Intel(R) Virtualization Technology
1812  * for Directed-IO Architecture Specifiction, Rev 2.2, Section 8.8
1813  * "Remapping Hardware Unit Hot Plug".
1814  */
1815 static guid_t dmar_hp_guid =
1816         GUID_INIT(0xD8C1A3A6, 0xBE9B, 0x4C9B,
1817                   0x91, 0xBF, 0xC3, 0xCB, 0x81, 0xFC, 0x5D, 0xAF);
1818
1819 /*
1820  * Currently there's only one revision and BIOS will not check the revision id,
1821  * so use 0 for safety.
1822  */
1823 #define DMAR_DSM_REV_ID                 0
1824 #define DMAR_DSM_FUNC_DRHD              1
1825 #define DMAR_DSM_FUNC_ATSR              2
1826 #define DMAR_DSM_FUNC_RHSA              3
1827
1828 static inline bool dmar_detect_dsm(acpi_handle handle, int func)
1829 {
1830         return acpi_check_dsm(handle, &dmar_hp_guid, DMAR_DSM_REV_ID, 1 << func);
1831 }
1832
1833 static int dmar_walk_dsm_resource(acpi_handle handle, int func,
1834                                   dmar_res_handler_t handler, void *arg)
1835 {
1836         int ret = -ENODEV;
1837         union acpi_object *obj;
1838         struct acpi_dmar_header *start;
1839         struct dmar_res_callback callback;
1840         static int res_type[] = {
1841                 [DMAR_DSM_FUNC_DRHD] = ACPI_DMAR_TYPE_HARDWARE_UNIT,
1842                 [DMAR_DSM_FUNC_ATSR] = ACPI_DMAR_TYPE_ROOT_ATS,
1843                 [DMAR_DSM_FUNC_RHSA] = ACPI_DMAR_TYPE_HARDWARE_AFFINITY,
1844         };
1845
1846         if (!dmar_detect_dsm(handle, func))
1847                 return 0;
1848
1849         obj = acpi_evaluate_dsm_typed(handle, &dmar_hp_guid, DMAR_DSM_REV_ID,
1850                                       func, NULL, ACPI_TYPE_BUFFER);
1851         if (!obj)
1852                 return -ENODEV;
1853
1854         memset(&callback, 0, sizeof(callback));
1855         callback.cb[res_type[func]] = handler;
1856         callback.arg[res_type[func]] = arg;
1857         start = (struct acpi_dmar_header *)obj->buffer.pointer;
1858         ret = dmar_walk_remapping_entries(start, obj->buffer.length, &callback);
1859
1860         ACPI_FREE(obj);
1861
1862         return ret;
1863 }
1864
1865 static int dmar_hp_add_drhd(struct acpi_dmar_header *header, void *arg)
1866 {
1867         int ret;
1868         struct dmar_drhd_unit *dmaru;
1869
1870         dmaru = dmar_find_dmaru((struct acpi_dmar_hardware_unit *)header);
1871         if (!dmaru)
1872                 return -ENODEV;
1873
1874         ret = dmar_ir_hotplug(dmaru, true);
1875         if (ret == 0)
1876                 ret = dmar_iommu_hotplug(dmaru, true);
1877
1878         return ret;
1879 }
1880
1881 static int dmar_hp_remove_drhd(struct acpi_dmar_header *header, void *arg)
1882 {
1883         int i, ret;
1884         struct device *dev;
1885         struct dmar_drhd_unit *dmaru;
1886
1887         dmaru = dmar_find_dmaru((struct acpi_dmar_hardware_unit *)header);
1888         if (!dmaru)
1889                 return 0;
1890
1891         /*
1892          * All PCI devices managed by this unit should have been destroyed.
1893          */
1894         if (!dmaru->include_all && dmaru->devices && dmaru->devices_cnt) {
1895                 for_each_active_dev_scope(dmaru->devices,
1896                                           dmaru->devices_cnt, i, dev)
1897                         return -EBUSY;
1898         }
1899
1900         ret = dmar_ir_hotplug(dmaru, false);
1901         if (ret == 0)
1902                 ret = dmar_iommu_hotplug(dmaru, false);
1903
1904         return ret;
1905 }
1906
1907 static int dmar_hp_release_drhd(struct acpi_dmar_header *header, void *arg)
1908 {
1909         struct dmar_drhd_unit *dmaru;
1910
1911         dmaru = dmar_find_dmaru((struct acpi_dmar_hardware_unit *)header);
1912         if (dmaru) {
1913                 list_del_rcu(&dmaru->list);
1914                 synchronize_rcu();
1915                 dmar_free_drhd(dmaru);
1916         }
1917
1918         return 0;
1919 }
1920
1921 static int dmar_hotplug_insert(acpi_handle handle)
1922 {
1923         int ret;
1924         int drhd_count = 0;
1925
1926         ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
1927                                      &dmar_validate_one_drhd, (void *)1);
1928         if (ret)
1929                 goto out;
1930
1931         ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
1932                                      &dmar_parse_one_drhd, (void *)&drhd_count);
1933         if (ret == 0 && drhd_count == 0) {
1934                 pr_warn(FW_BUG "No DRHD structures in buffer returned by _DSM method\n");
1935                 goto out;
1936         } else if (ret) {
1937                 goto release_drhd;
1938         }
1939
1940         ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_RHSA,
1941                                      &dmar_parse_one_rhsa, NULL);
1942         if (ret)
1943                 goto release_drhd;
1944
1945         ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
1946                                      &dmar_parse_one_atsr, NULL);
1947         if (ret)
1948                 goto release_atsr;
1949
1950         ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
1951                                      &dmar_hp_add_drhd, NULL);
1952         if (!ret)
1953                 return 0;
1954
1955         dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
1956                                &dmar_hp_remove_drhd, NULL);
1957 release_atsr:
1958         dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
1959                                &dmar_release_one_atsr, NULL);
1960 release_drhd:
1961         dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
1962                                &dmar_hp_release_drhd, NULL);
1963 out:
1964         return ret;
1965 }
1966
1967 static int dmar_hotplug_remove(acpi_handle handle)
1968 {
1969         int ret;
1970
1971         ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
1972                                      &dmar_check_one_atsr, NULL);
1973         if (ret)
1974                 return ret;
1975
1976         ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
1977                                      &dmar_hp_remove_drhd, NULL);
1978         if (ret == 0) {
1979                 WARN_ON(dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
1980                                                &dmar_release_one_atsr, NULL));
1981                 WARN_ON(dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
1982                                                &dmar_hp_release_drhd, NULL));
1983         } else {
1984                 dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
1985                                        &dmar_hp_add_drhd, NULL);
1986         }
1987
1988         return ret;
1989 }
1990
1991 static acpi_status dmar_get_dsm_handle(acpi_handle handle, u32 lvl,
1992                                        void *context, void **retval)
1993 {
1994         acpi_handle *phdl = retval;
1995
1996         if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) {
1997                 *phdl = handle;
1998                 return AE_CTRL_TERMINATE;
1999         }
2000
2001         return AE_OK;
2002 }
2003
2004 static int dmar_device_hotplug(acpi_handle handle, bool insert)
2005 {
2006         int ret;
2007         acpi_handle tmp = NULL;
2008         acpi_status status;
2009
2010         if (!dmar_in_use())
2011                 return 0;
2012
2013         if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) {
2014                 tmp = handle;
2015         } else {
2016                 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
2017                                              ACPI_UINT32_MAX,
2018                                              dmar_get_dsm_handle,
2019                                              NULL, NULL, &tmp);
2020                 if (ACPI_FAILURE(status)) {
2021                         pr_warn("Failed to locate _DSM method.\n");
2022                         return -ENXIO;
2023                 }
2024         }
2025         if (tmp == NULL)
2026                 return 0;
2027
2028         down_write(&dmar_global_lock);
2029         if (insert)
2030                 ret = dmar_hotplug_insert(tmp);
2031         else
2032                 ret = dmar_hotplug_remove(tmp);
2033         up_write(&dmar_global_lock);
2034
2035         return ret;
2036 }
2037
2038 int dmar_device_add(acpi_handle handle)
2039 {
2040         return dmar_device_hotplug(handle, true);
2041 }
2042
2043 int dmar_device_remove(acpi_handle handle)
2044 {
2045         return dmar_device_hotplug(handle, false);
2046 }