drivers/pci/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 #include <linux/pci.h>
  30 #include <linux/dmar.h>
  31 #include <linux/iova.h>
  32 #include <linux/intel-iommu.h>
  33 #include <linux/timer.h>
  34
  35 #undef PREFIX
  36 #define PREFIX "DMAR:"
  37
  38 /* No locks are needed as DMA remapping hardware unit
  39  * list is constructed at boot time and hotplug of
  40  * these units are not supported by the architecture.
  41  */
  42 LIST_HEAD(dmar_drhd_units);
  43
  44 static struct acpi_table_header * __initdata dmar_tbl;
  45
  46 static void __init dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
  47 {
  48         /*
  49          * add INCLUDE_ALL at the tail, so scan the list will find it at
  50          * the very end.
  51          */
  52         if (drhd->include_all)
  53                 list_add_tail(&drhd->list, &dmar_drhd_units);
  54         else
  55                 list_add(&drhd->list, &dmar_drhd_units);
  56 }
  57
  58 static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
  59                                            struct pci_dev **dev, u16 segment)
  60 {
  61         struct pci_bus *bus;
  62         struct pci_dev *pdev = NULL;
  63         struct acpi_dmar_pci_path *path;
  64         int count;
  65
  66         bus = pci_find_bus(segment, scope->bus);
  67         path = (struct acpi_dmar_pci_path *)(scope + 1);
  68         count = (scope->length - sizeof(struct acpi_dmar_device_scope))
  69                 / sizeof(struct acpi_dmar_pci_path);
  70
  71         while (count) {
  72                 if (pdev)
  73                         pci_dev_put(pdev);
  74                 /*
  75                  * Some BIOSes list non-exist devices in DMAR table, just
  76                  * ignore it
  77                  */
  78                 if (!bus) {
  79                         printk(KERN_WARNING
  80                         PREFIX "Device scope bus [%d] not found\n",
  81                         scope->bus);
  82                         break;
  83                 }
  84                 pdev = pci_get_slot(bus, PCI_DEVFN(path->dev, path->fn));
  85                 if (!pdev) {
  86                         printk(KERN_WARNING PREFIX
  87                         "Device scope device [%04x:%02x:%02x.%02x] not found\n",
  88                                 segment, bus->number, path->dev, path->fn);
  89                         break;
  90                 }
  91                 path ++;
  92                 count --;
  93                 bus = pdev->subordinate;
  94         }
  95         if (!pdev) {
  96                 printk(KERN_WARNING PREFIX
  97                 "Device scope device [%04x:%02x:%02x.%02x] not found\n",
  98                 segment, scope->bus, path->dev, path->fn);
  99                 *dev = NULL;
 100                 return 0;
 101         }
 102         if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT && \
 103                         pdev->subordinate) || (scope->entry_type == \
 104                         ACPI_DMAR_SCOPE_TYPE_BRIDGE && !pdev->subordinate)) {
 105                 pci_dev_put(pdev);
 106                 printk(KERN_WARNING PREFIX
 107                         "Device scope type does not match for %s\n",
 108                          pci_name(pdev));
 109                 return -EINVAL;
 110         }
 111         *dev = pdev;
 112         return 0;
 113 }
 114
 115 static int __init dmar_parse_dev_scope(void *start, void *end, int *cnt,
 116                                        struct pci_dev ***devices, u16 segment)
 117 {
 118         struct acpi_dmar_device_scope *scope;
 119         void * tmp = start;
 120         int index;
 121         int ret;
 122
 123         *cnt = 0;
 124         while (start < end) {
 125                 scope = start;
 126                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
 127                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE)
 128                         (*cnt)++;
 129                 else
 130                         printk(KERN_WARNING PREFIX
 131                                 "Unsupported device scope\n");
 132                 start += scope->length;
 133         }
 134         if (*cnt == 0)
 135                 return 0;
 136
 137         *devices = kcalloc(*cnt, sizeof(struct pci_dev *), GFP_KERNEL);
 138         if (!*devices)
 139                 return -ENOMEM;
 140
 141         start = tmp;
 142         index = 0;
 143         while (start < end) {
 144                 scope = start;
 145                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
 146                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE) {
 147                         ret = dmar_parse_one_dev_scope(scope,
 148                                 &(*devices)[index], segment);
 149                         if (ret) {
 150                                 kfree(*devices);
 151                                 return ret;
 152                         }
 153                         index ++;
 154                 }
 155                 start += scope->length;
 156         }
 157
 158         return 0;
 159 }
 160
 161 /**
 162  * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition
 163  * structure which uniquely represent one DMA remapping hardware unit
 164  * present in the platform
 165  */
 166 static int __init
 167 dmar_parse_one_drhd(struct acpi_dmar_header *header)
 168 {
 169         struct acpi_dmar_hardware_unit *drhd;
 170         struct dmar_drhd_unit *dmaru;
 171         int ret = 0;
 172
 173         dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL);
 174         if (!dmaru)
 175                 return -ENOMEM;
 176
 177         dmaru->hdr = header;
 178         drhd = (struct acpi_dmar_hardware_unit *)header;
 179         dmaru->reg_base_addr = drhd->address;
 180         dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */
 181
 182         ret = alloc_iommu(dmaru);
 183         if (ret) {
 184                 kfree(dmaru);
 185                 return ret;
 186         }
 187         dmar_register_drhd_unit(dmaru);
 188         return 0;
 189 }
 190
 191 static int __init dmar_parse_dev(struct dmar_drhd_unit *dmaru)
 192 {
 193         struct acpi_dmar_hardware_unit *drhd;
 194         static int include_all;
 195         int ret = 0;
 196
 197         drhd = (struct acpi_dmar_hardware_unit *) dmaru->hdr;
 198
 199         if (!dmaru->include_all)
 200                 ret = dmar_parse_dev_scope((void *)(drhd + 1),
 201                                 ((void *)drhd) + drhd->header.length,
 202                                 &dmaru->devices_cnt, &dmaru->devices,
 203                                 drhd->segment);
 204         else {
 205                 /* Only allow one INCLUDE_ALL */
 206                 if (include_all) {
 207                         printk(KERN_WARNING PREFIX "Only one INCLUDE_ALL "
 208                                 "device scope is allowed\n");
 209                         ret = -EINVAL;
 210                 }
 211                 include_all = 1;
 212         }
 213
 214         if (ret) {
 215                 list_del(&dmaru->list);
 216                 kfree(dmaru);
 217         }
 218         return ret;
 219 }
 220
 221 #ifdef CONFIG_DMAR
 222 LIST_HEAD(dmar_rmrr_units);
 223
 224 static void __init dmar_register_rmrr_unit(struct dmar_rmrr_unit *rmrr)
 225 {
 226         list_add(&rmrr->list, &dmar_rmrr_units);
 227 }
 228
 229
 230 static int __init
 231 dmar_parse_one_rmrr(struct acpi_dmar_header *header)
 232 {
 233         struct acpi_dmar_reserved_memory *rmrr;
 234         struct dmar_rmrr_unit *rmrru;
 235
 236         rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
 237         if (!rmrru)
 238                 return -ENOMEM;
 239
 240         rmrru->hdr = header;
 241         rmrr = (struct acpi_dmar_reserved_memory *)header;
 242         rmrru->base_address = rmrr->base_address;
 243         rmrru->end_address = rmrr->end_address;
 244
 245         dmar_register_rmrr_unit(rmrru);
 246         return 0;
 247 }
 248
 249 static int __init
 250 rmrr_parse_dev(struct dmar_rmrr_unit *rmrru)
 251 {
 252         struct acpi_dmar_reserved_memory *rmrr;
 253         int ret;
 254
 255         rmrr = (struct acpi_dmar_reserved_memory *) rmrru->hdr;
 256         ret = dmar_parse_dev_scope((void *)(rmrr + 1),
 257                 ((void *)rmrr) + rmrr->header.length,
 258                 &rmrru->devices_cnt, &rmrru->devices, rmrr->segment);
 259
 260         if (ret || (rmrru->devices_cnt == 0)) {
 261                 list_del(&rmrru->list);
 262                 kfree(rmrru);
 263         }
 264         return ret;
 265 }
 266 #endif
 267
 268 static void __init
 269 dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
 270 {
 271         struct acpi_dmar_hardware_unit *drhd;
 272         struct acpi_dmar_reserved_memory *rmrr;
 273
 274         switch (header->type) {
 275         case ACPI_DMAR_TYPE_HARDWARE_UNIT:
 276                 drhd = (struct acpi_dmar_hardware_unit *)header;
 277                 printk (KERN_INFO PREFIX
 278                         "DRHD (flags: 0x%08x)base: 0x%016Lx\n",
 279                         drhd->flags, (unsigned long long)drhd->address);
 280                 break;
 281         case ACPI_DMAR_TYPE_RESERVED_MEMORY:
 282                 rmrr = (struct acpi_dmar_reserved_memory *)header;
 283
 284                 printk (KERN_INFO PREFIX
 285                         "RMRR base: 0x%016Lx end: 0x%016Lx\n",
 286                         (unsigned long long)rmrr->base_address,
 287                         (unsigned long long)rmrr->end_address);
 288                 break;
 289         }
 290 }
 291
 292 /**
 293  * dmar_table_detect - checks to see if the platform supports DMAR devices
 294  */
 295 static int __init dmar_table_detect(void)
 296 {
 297         acpi_status status = AE_OK;
 298
 299         /* if we could find DMAR table, then there are DMAR devices */
 300         status = acpi_get_table(ACPI_SIG_DMAR, 0,
 301                                 (struct acpi_table_header **)&dmar_tbl);
 302
 303         if (ACPI_SUCCESS(status) && !dmar_tbl) {
 304                 printk (KERN_WARNING PREFIX "Unable to map DMAR\n");
 305                 status = AE_NOT_FOUND;
 306         }
 307
 308         return (ACPI_SUCCESS(status) ? 1 : 0);
 309 }
 310
 311 /**
 312  * parse_dmar_table - parses the DMA reporting table
 313  */
 314 static int __init
 315 parse_dmar_table(void)
 316 {
 317         struct acpi_table_dmar *dmar;
 318         struct acpi_dmar_header *entry_header;
 319         int ret = 0;
 320
 321         /*
 322          * Do it again, earlier dmar_tbl mapping could be mapped with
 323          * fixed map.
 324          */
 325         dmar_table_detect();
 326
 327         dmar = (struct acpi_table_dmar *)dmar_tbl;
 328         if (!dmar)
 329                 return -ENODEV;
 330
 331         if (dmar->width < PAGE_SHIFT - 1) {
 332                 printk(KERN_WARNING PREFIX "Invalid DMAR haw\n");
 333                 return -EINVAL;
 334         }
 335
 336         printk (KERN_INFO PREFIX "Host address width %d\n",
 337                 dmar->width + 1);
 338
 339         entry_header = (struct acpi_dmar_header *)(dmar + 1);
 340         while (((unsigned long)entry_header) <
 341                         (((unsigned long)dmar) + dmar_tbl->length)) {
 342                 dmar_table_print_dmar_entry(entry_header);
 343
 344                 switch (entry_header->type) {
 345                 case ACPI_DMAR_TYPE_HARDWARE_UNIT:
 346                         ret = dmar_parse_one_drhd(entry_header);
 347                         break;
 348                 case ACPI_DMAR_TYPE_RESERVED_MEMORY:
 349 #ifdef CONFIG_DMAR
 350                         ret = dmar_parse_one_rmrr(entry_header);
 351 #endif
 352                         break;
 353                 default:
 354                         printk(KERN_WARNING PREFIX
 355                                 "Unknown DMAR structure type\n");
 356                         ret = 0; /* for forward compatibility */
 357                         break;
 358                 }
 359                 if (ret)
 360                         break;
 361
 362                 entry_header = ((void *)entry_header + entry_header->length);
 363         }
 364         return ret;
 365 }
 366
 367 int dmar_pci_device_match(struct pci_dev *devices[], int cnt,
 368                           struct pci_dev *dev)
 369 {
 370         int index;
 371
 372         while (dev) {
 373                 for (index = 0; index < cnt; index++)
 374                         if (dev == devices[index])
 375                                 return 1;
 376
 377                 /* Check our parent */
 378                 dev = dev->bus->self;
 379         }
 380
 381         return 0;
 382 }
 383
 384 struct dmar_drhd_unit *
 385 dmar_find_matched_drhd_unit(struct pci_dev *dev)
 386 {
 387         struct dmar_drhd_unit *drhd = NULL;
 388
 389         list_for_each_entry(drhd, &dmar_drhd_units, list) {
 390                 if (drhd->include_all || dmar_pci_device_match(drhd->devices,
 391                                                 drhd->devices_cnt, dev))
 392                         return drhd;
 393         }
 394
 395         return NULL;
 396 }
 397
 398 int __init dmar_dev_scope_init(void)
 399 {
 400         struct dmar_drhd_unit *drhd, *drhd_n;
 401         int ret = -ENODEV;
 402
 403         list_for_each_entry_safe(drhd, drhd_n, &dmar_drhd_units, list) {
 404                 ret = dmar_parse_dev(drhd);
 405                 if (ret)
 406                         return ret;
 407         }
 408
 409 #ifdef CONFIG_DMAR
 410         {
 411                 struct dmar_rmrr_unit *rmrr, *rmrr_n;
 412                 list_for_each_entry_safe(rmrr, rmrr_n, &dmar_rmrr_units, list) {
 413                         ret = rmrr_parse_dev(rmrr);
 414                         if (ret)
 415                                 return ret;
 416                 }
 417         }
 418 #endif
 419
 420         return ret;
 421 }
 422
 423
 424 int __init dmar_table_init(void)
 425 {
 426         static int dmar_table_initialized;
 427         int ret;
 428
 429         if (dmar_table_initialized)
 430                 return 0;
 431
 432         dmar_table_initialized = 1;
 433
 434         ret = parse_dmar_table();
 435         if (ret) {
 436                 if (ret != -ENODEV)
 437                         printk(KERN_INFO PREFIX "parse DMAR table failure.\n");
 438                 return ret;
 439         }
 440
 441         if (list_empty(&dmar_drhd_units)) {
 442                 printk(KERN_INFO PREFIX "No DMAR devices found\n");
 443                 return -ENODEV;
 444         }
 445
 446 #ifdef CONFIG_DMAR
 447         if (list_empty(&dmar_rmrr_units))
 448                 printk(KERN_INFO PREFIX "No RMRR found\n");
 449 #endif
 450
 451 #ifdef CONFIG_INTR_REMAP
 452         parse_ioapics_under_ir();
 453 #endif
 454         return 0;
 455 }
 456
 457 void __init detect_intel_iommu(void)
 458 {
 459         int ret;
 460
 461         ret = dmar_table_detect();
 462
 463         {
 464 #ifdef CONFIG_INTR_REMAP
 465                 struct acpi_table_dmar *dmar;
 466                 /*
 467                  * for now we will disable dma-remapping when interrupt
 468                  * remapping is enabled.
 469                  * When support for queued invalidation for IOTLB invalidation
 470                  * is added, we will not need this any more.
 471                  */
 472                 dmar = (struct acpi_table_dmar *) dmar_tbl;
 473                 if (ret && cpu_has_x2apic && dmar->flags & 0x1)
 474                         printk(KERN_INFO
 475                                "Queued invalidation will be enabled to support "
 476                                "x2apic and Intr-remapping.\n");
 477 #endif
 478 #ifdef CONFIG_DMAR
 479                 if (ret && !no_iommu && !iommu_detected && !swiotlb &&
 480                     !dmar_disabled)
 481                         iommu_detected = 1;
 482 #endif
 483         }
 484         dmar_tbl = NULL;
 485 }
 486
 487
 488 int alloc_iommu(struct dmar_drhd_unit *drhd)
 489 {
 490         struct intel_iommu *iommu;
 491         int map_size;
 492         u32 ver;
 493         static int iommu_allocated = 0;
 494
 495         iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
 496         if (!iommu)
 497                 return -ENOMEM;
 498
 499         iommu->seq_id = iommu_allocated++;
 500
 501         iommu->reg = ioremap(drhd->reg_base_addr, VTD_PAGE_SIZE);
 502         if (!iommu->reg) {
 503                 printk(KERN_ERR "IOMMU: can't map the region\n");
 504                 goto error;
 505         }
 506         iommu->cap = dmar_readq(iommu->reg + DMAR_CAP_REG);
 507         iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG);
 508
 509         /* the registers might be more than one page */
 510         map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),
 511                 cap_max_fault_reg_offset(iommu->cap));
 512         map_size = VTD_PAGE_ALIGN(map_size);
 513         if (map_size > VTD_PAGE_SIZE) {
 514                 iounmap(iommu->reg);
 515                 iommu->reg = ioremap(drhd->reg_base_addr, map_size);
 516                 if (!iommu->reg) {
 517                         printk(KERN_ERR "IOMMU: can't map the region\n");
 518                         goto error;
 519                 }
 520         }
 521
 522         ver = readl(iommu->reg + DMAR_VER_REG);
 523         pr_debug("IOMMU %llx: ver %d:%d cap %llx ecap %llx\n",
 524                 (unsigned long long)drhd->reg_base_addr,
 525                 DMAR_VER_MAJOR(ver), DMAR_VER_MINOR(ver),
 526                 (unsigned long long)iommu->cap,
 527                 (unsigned long long)iommu->ecap);
 528
 529         spin_lock_init(&iommu->register_lock);
 530
 531         drhd->iommu = iommu;
 532         return 0;
 533 error:
 534         kfree(iommu);
 535         return -1;
 536 }
 537
 538 void free_iommu(struct intel_iommu *iommu)
 539 {
 540         if (!iommu)
 541                 return;
 542
 543 #ifdef CONFIG_DMAR
 544         free_dmar_iommu(iommu);
 545 #endif
 546
 547         if (iommu->reg)
 548                 iounmap(iommu->reg);
 549         kfree(iommu);
 550 }
 551
 552 /*
 553  * Reclaim all the submitted descriptors which have completed its work.
 554  */
 555 static inline void reclaim_free_desc(struct q_inval *qi)
 556 {
 557         while (qi->desc_status[qi->free_tail] == QI_DONE) {
 558                 qi->desc_status[qi->free_tail] = QI_FREE;
 559                 qi->free_tail = (qi->free_tail + 1) % QI_LENGTH;
 560                 qi->free_cnt++;
 561         }
 562 }
 563
 564 /*
 565  * Submit the queued invalidation descriptor to the remapping
 566  * hardware unit and wait for its completion.
 567  */
 568 void qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu)
 569 {
 570         struct q_inval *qi = iommu->qi;
 571         struct qi_desc *hw, wait_desc;
 572         int wait_index, index;
 573         unsigned long flags;
 574
 575         if (!qi)
 576                 return;
 577
 578         hw = qi->desc;
 579
 580         spin_lock_irqsave(&qi->q_lock, flags);
 581         while (qi->free_cnt < 3) {
 582                 spin_unlock_irqrestore(&qi->q_lock, flags);
 583                 cpu_relax();
 584                 spin_lock_irqsave(&qi->q_lock, flags);
 585         }
 586
 587         index = qi->free_head;
 588         wait_index = (index + 1) % QI_LENGTH;
 589
 590         qi->desc_status[index] = qi->desc_status[wait_index] = QI_IN_USE;
 591
 592         hw[index] = *desc;
 593
 594         wait_desc.low = QI_IWD_STATUS_DATA(2) | QI_IWD_STATUS_WRITE | QI_IWD_TYPE;
 595         wait_desc.high = virt_to_phys(&qi->desc_status[wait_index]);
 596
 597         hw[wait_index] = wait_desc;
 598
 599         __iommu_flush_cache(iommu, &hw[index], sizeof(struct qi_desc));
 600         __iommu_flush_cache(iommu, &hw[wait_index], sizeof(struct qi_desc));
 601
 602         qi->free_head = (qi->free_head + 2) % QI_LENGTH;
 603         qi->free_cnt -= 2;
 604
 605         spin_lock(&iommu->register_lock);
 606         /*
 607          * update the HW tail register indicating the presence of
 608          * new descriptors.
 609          */
 610         writel(qi->free_head << 4, iommu->reg + DMAR_IQT_REG);
 611         spin_unlock(&iommu->register_lock);
 612
 613         while (qi->desc_status[wait_index] != QI_DONE) {
 614                 /*
 615                  * We will leave the interrupts disabled, to prevent interrupt
 616                  * context to queue another cmd while a cmd is already submitted
 617                  * and waiting for completion on this cpu. This is to avoid
 618                  * a deadlock where the interrupt context can wait indefinitely
 619                  * for free slots in the queue.
 620                  */
 621                 spin_unlock(&qi->q_lock);
 622                 cpu_relax();
 623                 spin_lock(&qi->q_lock);
 624         }
 625
 626         qi->desc_status[index] = QI_DONE;
 627
 628         reclaim_free_desc(qi);
 629         spin_unlock_irqrestore(&qi->q_lock, flags);
 630 }
 631
 632 /*
 633  * Flush the global interrupt entry cache.
 634  */
 635 void qi_global_iec(struct intel_iommu *iommu)
 636 {
 637         struct qi_desc desc;
 638
 639         desc.low = QI_IEC_TYPE;
 640         desc.high = 0;
 641
 642         qi_submit_sync(&desc, iommu);
 643 }
 644
 645 int qi_flush_context(struct intel_iommu *iommu, u16 did, u16 sid, u8 fm,
 646                      u64 type, int non_present_entry_flush)
 647 {
 648
 649         struct qi_desc desc;
 650
 651         if (non_present_entry_flush) {
 652                 if (!cap_caching_mode(iommu->cap))
 653                         return 1;
 654                 else
 655                         did = 0;
 656         }
 657
 658         desc.low = QI_CC_FM(fm) | QI_CC_SID(sid) | QI_CC_DID(did)
 659                         | QI_CC_GRAN(type) | QI_CC_TYPE;
 660         desc.high = 0;
 661
 662         qi_submit_sync(&desc, iommu);
 663
 664         return 0;
 665
 666 }
 667
 668 int qi_flush_iotlb(struct intel_iommu *iommu, u16 did, u64 addr,
 669                    unsigned int size_order, u64 type,
 670                    int non_present_entry_flush)
 671 {
 672         u8 dw = 0, dr = 0;
 673
 674         struct qi_desc desc;
 675         int ih = 0;
 676
 677         if (non_present_entry_flush) {
 678                 if (!cap_caching_mode(iommu->cap))
 679                         return 1;
 680                 else
 681                         did = 0;
 682         }
 683
 684         if (cap_write_drain(iommu->cap))
 685                 dw = 1;
 686
 687         if (cap_read_drain(iommu->cap))
 688                 dr = 1;
 689
 690         desc.low = QI_IOTLB_DID(did) | QI_IOTLB_DR(dr) | QI_IOTLB_DW(dw)
 691                 | QI_IOTLB_GRAN(type) | QI_IOTLB_TYPE;
 692         desc.high = QI_IOTLB_ADDR(addr) | QI_IOTLB_IH(ih)
 693                 | QI_IOTLB_AM(size_order);
 694
 695         qi_submit_sync(&desc, iommu);
 696
 697         return 0;
 698
 699 }
 700
 701 /*
 702  * Enable Queued Invalidation interface. This is a must to support
 703  * interrupt-remapping. Also used by DMA-remapping, which replaces
 704  * register based IOTLB invalidation.
 705  */
 706 int dmar_enable_qi(struct intel_iommu *iommu)
 707 {
 708         u32 cmd, sts;
 709         unsigned long flags;
 710         struct q_inval *qi;
 711
 712         if (!ecap_qis(iommu->ecap))
 713                 return -ENOENT;
 714
 715         /*
 716          * queued invalidation is already setup and enabled.
 717          */
 718         if (iommu->qi)
 719                 return 0;
 720
 721         iommu->qi = kmalloc(sizeof(*qi), GFP_KERNEL);
 722         if (!iommu->qi)
 723                 return -ENOMEM;
 724
 725         qi = iommu->qi;
 726
 727         qi->desc = (void *)(get_zeroed_page(GFP_KERNEL));
 728         if (!qi->desc) {
 729                 kfree(qi);
 730                 iommu->qi = 0;
 731                 return -ENOMEM;
 732         }
 733
 734         qi->desc_status = kmalloc(QI_LENGTH * sizeof(int), GFP_KERNEL);
 735         if (!qi->desc_status) {
 736                 free_page((unsigned long) qi->desc);
 737                 kfree(qi);
 738                 iommu->qi = 0;
 739                 return -ENOMEM;
 740         }
 741
 742         qi->free_head = qi->free_tail = 0;
 743         qi->free_cnt = QI_LENGTH;
 744
 745         spin_lock_init(&qi->q_lock);
 746
 747         spin_lock_irqsave(&iommu->register_lock, flags);
 748         /* write zero to the tail reg */
 749         writel(0, iommu->reg + DMAR_IQT_REG);
 750
 751         dmar_writeq(iommu->reg + DMAR_IQA_REG, virt_to_phys(qi->desc));
 752
 753         cmd = iommu->gcmd | DMA_GCMD_QIE;
 754         iommu->gcmd |= DMA_GCMD_QIE;
 755         writel(cmd, iommu->reg + DMAR_GCMD_REG);
 756
 757         /* Make sure hardware complete it */
 758         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl, (sts & DMA_GSTS_QIES), sts);
 759         spin_unlock_irqrestore(&iommu->register_lock, flags);
 760
 761         return 0;
 762 }