drivers/pci/intr_remapping.c

   1 #include <linux/interrupt.h>
   2 #include <linux/dmar.h>
   3 #include <linux/spinlock.h>
   4 #include <linux/slab.h>
   5 #include <linux/jiffies.h>
   6 #include <linux/hpet.h>
   7 #include <linux/pci.h>
   8 #include <linux/irq.h>
   9 #include <asm/io_apic.h>
  10 #include <asm/smp.h>
  11 #include <asm/cpu.h>
  12 #include <linux/intel-iommu.h>
  13 #include "intr_remapping.h"
  14 #include <acpi/acpi.h>
  15 #include <asm/pci-direct.h>
  16 #include "pci.h"
  17
  18 static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
  19 static struct hpet_scope ir_hpet[MAX_HPET_TBS];
  20 static int ir_ioapic_num, ir_hpet_num;
  21 int intr_remapping_enabled;
  22
  23 static int disable_intremap;
  24 static int disable_sourceid_checking;
  25
  26 static __init int setup_nointremap(char *str)
  27 {
  28         disable_intremap = 1;
  29         return 0;
  30 }
  31 early_param("nointremap", setup_nointremap);
  32
  33 static __init int setup_intremap(char *str)
  34 {
  35         if (!str)
  36                 return -EINVAL;
  37
  38         if (!strncmp(str, "on", 2))
  39                 disable_intremap = 0;
  40         else if (!strncmp(str, "off", 3))
  41                 disable_intremap = 1;
  42         else if (!strncmp(str, "nosid", 5))
  43                 disable_sourceid_checking = 1;
  44
  45         return 0;
  46 }
  47 early_param("intremap", setup_intremap);
  48
  49 static DEFINE_SPINLOCK(irq_2_ir_lock);
  50
  51 static struct irq_2_iommu *irq_2_iommu(unsigned int irq)
  52 {
  53         struct irq_cfg *cfg = get_irq_chip_data(irq);
  54         return cfg ? &cfg->irq_2_iommu : NULL;
  55 }
  56
  57 int irq_remapped(int irq)
  58 {
  59         struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
  60
  61         return irq_iommu ? irq_iommu->iommu != NULL : 0;
  62 }
  63
  64 int get_irte(int irq, struct irte *entry)
  65 {
  66         struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
  67         unsigned long flags;
  68         int index;
  69
  70         if (!entry || !irq_iommu)
  71                 return -1;
  72
  73         spin_lock_irqsave(&irq_2_ir_lock, flags);
  74
  75         index = irq_iommu->irte_index + irq_iommu->sub_handle;
  76         *entry = *(irq_iommu->iommu->ir_table->base + index);
  77
  78         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
  79         return 0;
  80 }
  81
  82 int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
  83 {
  84         struct ir_table *table = iommu->ir_table;
  85         struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
  86         u16 index, start_index;
  87         unsigned int mask = 0;
  88         unsigned long flags;
  89         int i;
  90
  91         if (!count || !irq_iommu)
  92                 return -1;
  93
  94         /*
  95          * start the IRTE search from index 0.
  96          */
  97         index = start_index = 0;
  98
  99         if (count > 1) {
 100                 count = __roundup_pow_of_two(count);
 101                 mask = ilog2(count);
 102         }
 103
 104         if (mask > ecap_max_handle_mask(iommu->ecap)) {
 105                 printk(KERN_ERR
 106                        "Requested mask %x exceeds the max invalidation handle"
 107                        " mask value %Lx\n", mask,
 108                        ecap_max_handle_mask(iommu->ecap));
 109                 return -1;
 110         }
 111
 112         spin_lock_irqsave(&irq_2_ir_lock, flags);
 113         do {
 114                 for (i = index; i < index + count; i++)
 115                         if  (table->base[i].present)
 116                                 break;
 117                 /* empty index found */
 118                 if (i == index + count)
 119                         break;
 120
 121                 index = (index + count) % INTR_REMAP_TABLE_ENTRIES;
 122
 123                 if (index == start_index) {
 124                         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 125                         printk(KERN_ERR "can't allocate an IRTE\n");
 126                         return -1;
 127                 }
 128         } while (1);
 129
 130         for (i = index; i < index + count; i++)
 131                 table->base[i].present = 1;
 132
 133         irq_iommu->iommu = iommu;
 134         irq_iommu->irte_index =  index;
 135         irq_iommu->sub_handle = 0;
 136         irq_iommu->irte_mask = mask;
 137
 138         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 139
 140         return index;
 141 }
 142
 143 static int qi_flush_iec(struct intel_iommu *iommu, int index, int mask)
 144 {
 145         struct qi_desc desc;
 146
 147         desc.low = QI_IEC_IIDEX(index) | QI_IEC_TYPE | QI_IEC_IM(mask)
 148                    | QI_IEC_SELECTIVE;
 149         desc.high = 0;
 150
 151         return qi_submit_sync(&desc, iommu);
 152 }
 153
 154 int map_irq_to_irte_handle(int irq, u16 *sub_handle)
 155 {
 156         struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
 157         unsigned long flags;
 158         int index;
 159
 160         if (!irq_iommu)
 161                 return -1;
 162
 163         spin_lock_irqsave(&irq_2_ir_lock, flags);
 164         *sub_handle = irq_iommu->sub_handle;
 165         index = irq_iommu->irte_index;
 166         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 167         return index;
 168 }
 169
 170 int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subhandle)
 171 {
 172         struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
 173         unsigned long flags;
 174
 175         if (!irq_iommu)
 176                 return -1;
 177
 178         spin_lock_irqsave(&irq_2_ir_lock, flags);
 179
 180         irq_iommu->iommu = iommu;
 181         irq_iommu->irte_index = index;
 182         irq_iommu->sub_handle = subhandle;
 183         irq_iommu->irte_mask = 0;
 184
 185         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 186
 187         return 0;
 188 }
 189
 190 int modify_irte(int irq, struct irte *irte_modified)
 191 {
 192         struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
 193         struct intel_iommu *iommu;
 194         unsigned long flags;
 195         struct irte *irte;
 196         int rc, index;
 197
 198         if (!irq_iommu)
 199                 return -1;
 200
 201         spin_lock_irqsave(&irq_2_ir_lock, flags);
 202
 203         iommu = irq_iommu->iommu;
 204
 205         index = irq_iommu->irte_index + irq_iommu->sub_handle;
 206         irte = &iommu->ir_table->base[index];
 207
 208         set_64bit(&irte->low, irte_modified->low);
 209         set_64bit(&irte->high, irte_modified->high);
 210         __iommu_flush_cache(iommu, irte, sizeof(*irte));
 211
 212         rc = qi_flush_iec(iommu, index, 0);
 213         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 214
 215         return rc;
 216 }
 217
 218 struct intel_iommu *map_hpet_to_ir(u8 hpet_id)
 219 {
 220         int i;
 221
 222         for (i = 0; i < MAX_HPET_TBS; i++)
 223                 if (ir_hpet[i].id == hpet_id)
 224                         return ir_hpet[i].iommu;
 225         return NULL;
 226 }
 227
 228 struct intel_iommu *map_ioapic_to_ir(int apic)
 229 {
 230         int i;
 231
 232         for (i = 0; i < MAX_IO_APICS; i++)
 233                 if (ir_ioapic[i].id == apic)
 234                         return ir_ioapic[i].iommu;
 235         return NULL;
 236 }
 237
 238 struct intel_iommu *map_dev_to_ir(struct pci_dev *dev)
 239 {
 240         struct dmar_drhd_unit *drhd;
 241
 242         drhd = dmar_find_matched_drhd_unit(dev);
 243         if (!drhd)
 244                 return NULL;
 245
 246         return drhd->iommu;
 247 }
 248
 249 static int clear_entries(struct irq_2_iommu *irq_iommu)
 250 {
 251         struct irte *start, *entry, *end;
 252         struct intel_iommu *iommu;
 253         int index;
 254
 255         if (irq_iommu->sub_handle)
 256                 return 0;
 257
 258         iommu = irq_iommu->iommu;
 259         index = irq_iommu->irte_index + irq_iommu->sub_handle;
 260
 261         start = iommu->ir_table->base + index;
 262         end = start + (1 << irq_iommu->irte_mask);
 263
 264         for (entry = start; entry < end; entry++) {
 265                 set_64bit(&entry->low, 0);
 266                 set_64bit(&entry->high, 0);
 267         }
 268
 269         return qi_flush_iec(iommu, index, irq_iommu->irte_mask);
 270 }
 271
 272 int free_irte(int irq)
 273 {
 274         struct irq_2_iommu *irq_iommu = irq_2_iommu(irq);
 275         unsigned long flags;
 276         int rc;
 277
 278         if (!irq_iommu)
 279                 return -1;
 280
 281         spin_lock_irqsave(&irq_2_ir_lock, flags);
 282
 283         rc = clear_entries(irq_iommu);
 284
 285         irq_iommu->iommu = NULL;
 286         irq_iommu->irte_index = 0;
 287         irq_iommu->sub_handle = 0;
 288         irq_iommu->irte_mask = 0;
 289
 290         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 291
 292         return rc;
 293 }
 294
 295 /*
 296  * source validation type
 297  */
 298 #define SVT_NO_VERIFY           0x0  /* no verification is required */
 299 #define SVT_VERIFY_SID_SQ       0x1  /* verify using SID and SQ fiels */
 300 #define SVT_VERIFY_BUS          0x2  /* verify bus of request-id */
 301
 302 /*
 303  * source-id qualifier
 304  */
 305 #define SQ_ALL_16       0x0  /* verify all 16 bits of request-id */
 306 #define SQ_13_IGNORE_1  0x1  /* verify most significant 13 bits, ignore
 307                               * the third least significant bit
 308                               */
 309 #define SQ_13_IGNORE_2  0x2  /* verify most significant 13 bits, ignore
 310                               * the second and third least significant bits
 311                               */
 312 #define SQ_13_IGNORE_3  0x3  /* verify most significant 13 bits, ignore
 313                               * the least three significant bits
 314                               */
 315
 316 /*
 317  * set SVT, SQ and SID fields of irte to verify
 318  * source ids of interrupt requests
 319  */
 320 static void set_irte_sid(struct irte *irte, unsigned int svt,
 321                          unsigned int sq, unsigned int sid)
 322 {
 323         if (disable_sourceid_checking)
 324                 svt = SVT_NO_VERIFY;
 325         irte->svt = svt;
 326         irte->sq = sq;
 327         irte->sid = sid;
 328 }
 329
 330 int set_ioapic_sid(struct irte *irte, int apic)
 331 {
 332         int i;
 333         u16 sid = 0;
 334
 335         if (!irte)
 336                 return -1;
 337
 338         for (i = 0; i < MAX_IO_APICS; i++) {
 339                 if (ir_ioapic[i].id == apic) {
 340                         sid = (ir_ioapic[i].bus << 8) | ir_ioapic[i].devfn;
 341                         break;
 342                 }
 343         }
 344
 345         if (sid == 0) {
 346                 pr_warning("Failed to set source-id of IOAPIC (%d)\n", apic);
 347                 return -1;
 348         }
 349
 350         set_irte_sid(irte, 1, 0, sid);
 351
 352         return 0;
 353 }
 354
 355 int set_hpet_sid(struct irte *irte, u8 id)
 356 {
 357         int i;
 358         u16 sid = 0;
 359
 360         if (!irte)
 361                 return -1;
 362
 363         for (i = 0; i < MAX_HPET_TBS; i++) {
 364                 if (ir_hpet[i].id == id) {
 365                         sid = (ir_hpet[i].bus << 8) | ir_hpet[i].devfn;
 366                         break;
 367                 }
 368         }
 369
 370         if (sid == 0) {
 371                 pr_warning("Failed to set source-id of HPET block (%d)\n", id);
 372                 return -1;
 373         }
 374
 375         /*
 376          * Should really use SQ_ALL_16. Some platforms are broken.
 377          * While we figure out the right quirks for these broken platforms, use
 378          * SQ_13_IGNORE_3 for now.
 379          */
 380         set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_13_IGNORE_3, sid);
 381
 382         return 0;
 383 }
 384
 385 int set_msi_sid(struct irte *irte, struct pci_dev *dev)
 386 {
 387         struct pci_dev *bridge;
 388
 389         if (!irte || !dev)
 390                 return -1;
 391
 392         /* PCIe device or Root Complex integrated PCI device */
 393         if (pci_is_pcie(dev) || !dev->bus->parent) {
 394                 set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_ALL_16,
 395                              (dev->bus->number << 8) | dev->devfn);
 396                 return 0;
 397         }
 398
 399         bridge = pci_find_upstream_pcie_bridge(dev);
 400         if (bridge) {
 401                 if (pci_is_pcie(bridge))/* this is a PCIe-to-PCI/PCIX bridge */
 402                         set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16,
 403                                 (bridge->bus->number << 8) | dev->bus->number);
 404                 else /* this is a legacy PCI bridge */
 405                         set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_ALL_16,
 406                                 (bridge->bus->number << 8) | bridge->devfn);
 407         }
 408
 409         return 0;
 410 }
 411
 412 static void iommu_set_intr_remapping(struct intel_iommu *iommu, int mode)
 413 {
 414         u64 addr;
 415         u32 sts;
 416         unsigned long flags;
 417
 418         addr = virt_to_phys((void *)iommu->ir_table->base);
 419
 420         spin_lock_irqsave(&iommu->register_lock, flags);
 421
 422         dmar_writeq(iommu->reg + DMAR_IRTA_REG,
 423                     (addr) | IR_X2APIC_MODE(mode) | INTR_REMAP_TABLE_REG_SIZE);
 424
 425         /* Set interrupt-remapping table pointer */
 426         iommu->gcmd |= DMA_GCMD_SIRTP;
 427         writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
 428
 429         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 430                       readl, (sts & DMA_GSTS_IRTPS), sts);
 431         spin_unlock_irqrestore(&iommu->register_lock, flags);
 432
 433         /*
 434          * global invalidation of interrupt entry cache before enabling
 435          * interrupt-remapping.
 436          */
 437         qi_global_iec(iommu);
 438
 439         spin_lock_irqsave(&iommu->register_lock, flags);
 440
 441         /* Enable interrupt-remapping */
 442         iommu->gcmd |= DMA_GCMD_IRE;
 443         writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
 444
 445         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 446                       readl, (sts & DMA_GSTS_IRES), sts);
 447
 448         spin_unlock_irqrestore(&iommu->register_lock, flags);
 449 }
 450
 451
 452 static int setup_intr_remapping(struct intel_iommu *iommu, int mode)
 453 {
 454         struct ir_table *ir_table;
 455         struct page *pages;
 456
 457         ir_table = iommu->ir_table = kzalloc(sizeof(struct ir_table),
 458                                              GFP_ATOMIC);
 459
 460         if (!iommu->ir_table)
 461                 return -ENOMEM;
 462
 463         pages = alloc_pages_node(iommu->node, GFP_ATOMIC | __GFP_ZERO,
 464                                  INTR_REMAP_PAGE_ORDER);
 465
 466         if (!pages) {
 467                 printk(KERN_ERR "failed to allocate pages of order %d\n",
 468                        INTR_REMAP_PAGE_ORDER);
 469                 kfree(iommu->ir_table);
 470                 return -ENOMEM;
 471         }
 472
 473         ir_table->base = page_address(pages);
 474
 475         iommu_set_intr_remapping(iommu, mode);
 476         return 0;
 477 }
 478
 479 /*
 480  * Disable Interrupt Remapping.
 481  */
 482 static void iommu_disable_intr_remapping(struct intel_iommu *iommu)
 483 {
 484         unsigned long flags;
 485         u32 sts;
 486
 487         if (!ecap_ir_support(iommu->ecap))
 488                 return;
 489
 490         /*
 491          * global invalidation of interrupt entry cache before disabling
 492          * interrupt-remapping.
 493          */
 494         qi_global_iec(iommu);
 495
 496         spin_lock_irqsave(&iommu->register_lock, flags);
 497
 498         sts = dmar_readq(iommu->reg + DMAR_GSTS_REG);
 499         if (!(sts & DMA_GSTS_IRES))
 500                 goto end;
 501
 502         iommu->gcmd &= ~DMA_GCMD_IRE;
 503         writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
 504
 505         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 506                       readl, !(sts & DMA_GSTS_IRES), sts);
 507
 508 end:
 509         spin_unlock_irqrestore(&iommu->register_lock, flags);
 510 }
 511
 512 int __init intr_remapping_supported(void)
 513 {
 514         struct dmar_drhd_unit *drhd;
 515
 516         if (disable_intremap)
 517                 return 0;
 518
 519         if (!dmar_ir_support())
 520                 return 0;
 521
 522         for_each_drhd_unit(drhd) {
 523                 struct intel_iommu *iommu = drhd->iommu;
 524
 525                 if (!ecap_ir_support(iommu->ecap))
 526                         return 0;
 527         }
 528
 529         return 1;
 530 }
 531
 532 int __init enable_intr_remapping(int eim)
 533 {
 534         struct dmar_drhd_unit *drhd;
 535         int setup = 0;
 536
 537         if (parse_ioapics_under_ir() != 1) {
 538                 printk(KERN_INFO "Not enable interrupt remapping\n");
 539                 return -1;
 540         }
 541
 542         for_each_drhd_unit(drhd) {
 543                 struct intel_iommu *iommu = drhd->iommu;
 544
 545                 /*
 546                  * If the queued invalidation is already initialized,
 547                  * shouldn't disable it.
 548                  */
 549                 if (iommu->qi)
 550                         continue;
 551
 552                 /*
 553                  * Clear previous faults.
 554                  */
 555                 dmar_fault(-1, iommu);
 556
 557                 /*
 558                  * Disable intr remapping and queued invalidation, if already
 559                  * enabled prior to OS handover.
 560                  */
 561                 iommu_disable_intr_remapping(iommu);
 562
 563                 dmar_disable_qi(iommu);
 564         }
 565
 566         /*
 567          * check for the Interrupt-remapping support
 568          */
 569         for_each_drhd_unit(drhd) {
 570                 struct intel_iommu *iommu = drhd->iommu;
 571
 572                 if (!ecap_ir_support(iommu->ecap))
 573                         continue;
 574
 575                 if (eim && !ecap_eim_support(iommu->ecap)) {
 576                         printk(KERN_INFO "DRHD %Lx: EIM not supported by DRHD, "
 577                                " ecap %Lx\n", drhd->reg_base_addr, iommu->ecap);
 578                         return -1;
 579                 }
 580         }
 581
 582         /*
 583          * Enable queued invalidation for all the DRHD's.
 584          */
 585         for_each_drhd_unit(drhd) {
 586                 int ret;
 587                 struct intel_iommu *iommu = drhd->iommu;
 588                 ret = dmar_enable_qi(iommu);
 589
 590                 if (ret) {
 591                         printk(KERN_ERR "DRHD %Lx: failed to enable queued, "
 592                                " invalidation, ecap %Lx, ret %d\n",
 593                                drhd->reg_base_addr, iommu->ecap, ret);
 594                         return -1;
 595                 }
 596         }
 597
 598         /*
 599          * Setup Interrupt-remapping for all the DRHD's now.
 600          */
 601         for_each_drhd_unit(drhd) {
 602                 struct intel_iommu *iommu = drhd->iommu;
 603
 604                 if (!ecap_ir_support(iommu->ecap))
 605                         continue;
 606
 607                 if (setup_intr_remapping(iommu, eim))
 608                         goto error;
 609
 610                 setup = 1;
 611         }
 612
 613         if (!setup)
 614                 goto error;
 615
 616         intr_remapping_enabled = 1;
 617
 618         return 0;
 619
 620 error:
 621         /*
 622          * handle error condition gracefully here!
 623          */
 624         return -1;
 625 }
 626
 627 static void ir_parse_one_hpet_scope(struct acpi_dmar_device_scope *scope,
 628                                       struct intel_iommu *iommu)
 629 {
 630         struct acpi_dmar_pci_path *path;
 631         u8 bus;
 632         int count;
 633
 634         bus = scope->bus;
 635         path = (struct acpi_dmar_pci_path *)(scope + 1);
 636         count = (scope->length - sizeof(struct acpi_dmar_device_scope))
 637                 / sizeof(struct acpi_dmar_pci_path);
 638
 639         while (--count > 0) {
 640                 /*
 641                  * Access PCI directly due to the PCI
 642                  * subsystem isn't initialized yet.
 643                  */
 644                 bus = read_pci_config_byte(bus, path->dev, path->fn,
 645                                            PCI_SECONDARY_BUS);
 646                 path++;
 647         }
 648         ir_hpet[ir_hpet_num].bus   = bus;
 649         ir_hpet[ir_hpet_num].devfn = PCI_DEVFN(path->dev, path->fn);
 650         ir_hpet[ir_hpet_num].iommu = iommu;
 651         ir_hpet[ir_hpet_num].id    = scope->enumeration_id;
 652         ir_hpet_num++;
 653 }
 654
 655 static void ir_parse_one_ioapic_scope(struct acpi_dmar_device_scope *scope,
 656                                       struct intel_iommu *iommu)
 657 {
 658         struct acpi_dmar_pci_path *path;
 659         u8 bus;
 660         int count;
 661
 662         bus = scope->bus;
 663         path = (struct acpi_dmar_pci_path *)(scope + 1);
 664         count = (scope->length - sizeof(struct acpi_dmar_device_scope))
 665                 / sizeof(struct acpi_dmar_pci_path);
 666
 667         while (--count > 0) {
 668                 /*
 669                  * Access PCI directly due to the PCI
 670                  * subsystem isn't initialized yet.
 671                  */
 672                 bus = read_pci_config_byte(bus, path->dev, path->fn,
 673                                            PCI_SECONDARY_BUS);
 674                 path++;
 675         }
 676
 677         ir_ioapic[ir_ioapic_num].bus   = bus;
 678         ir_ioapic[ir_ioapic_num].devfn = PCI_DEVFN(path->dev, path->fn);
 679         ir_ioapic[ir_ioapic_num].iommu = iommu;
 680         ir_ioapic[ir_ioapic_num].id    = scope->enumeration_id;
 681         ir_ioapic_num++;
 682 }
 683
 684 static int ir_parse_ioapic_hpet_scope(struct acpi_dmar_header *header,
 685                                       struct intel_iommu *iommu)
 686 {
 687         struct acpi_dmar_hardware_unit *drhd;
 688         struct acpi_dmar_device_scope *scope;
 689         void *start, *end;
 690
 691         drhd = (struct acpi_dmar_hardware_unit *)header;
 692
 693         start = (void *)(drhd + 1);
 694         end = ((void *)drhd) + header->length;
 695
 696         while (start < end) {
 697                 scope = start;
 698                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_IOAPIC) {
 699                         if (ir_ioapic_num == MAX_IO_APICS) {
 700                                 printk(KERN_WARNING "Exceeded Max IO APICS\n");
 701                                 return -1;
 702                         }
 703
 704                         printk(KERN_INFO "IOAPIC id %d under DRHD base "
 705                                " 0x%Lx IOMMU %d\n", scope->enumeration_id,
 706                                drhd->address, iommu->seq_id);
 707
 708                         ir_parse_one_ioapic_scope(scope, iommu);
 709                 } else if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_HPET) {
 710                         if (ir_hpet_num == MAX_HPET_TBS) {
 711                                 printk(KERN_WARNING "Exceeded Max HPET blocks\n");
 712                                 return -1;
 713                         }
 714
 715                         printk(KERN_INFO "HPET id %d under DRHD base"
 716                                " 0x%Lx\n", scope->enumeration_id,
 717                                drhd->address);
 718
 719                         ir_parse_one_hpet_scope(scope, iommu);
 720                 }
 721                 start += scope->length;
 722         }
 723
 724         return 0;
 725 }
 726
 727 /*
 728  * Finds the assocaition between IOAPIC's and its Interrupt-remapping
 729  * hardware unit.
 730  */
 731 int __init parse_ioapics_under_ir(void)
 732 {
 733         struct dmar_drhd_unit *drhd;
 734         int ir_supported = 0;
 735
 736         for_each_drhd_unit(drhd) {
 737                 struct intel_iommu *iommu = drhd->iommu;
 738
 739                 if (ecap_ir_support(iommu->ecap)) {
 740                         if (ir_parse_ioapic_hpet_scope(drhd->hdr, iommu))
 741                                 return -1;
 742
 743                         ir_supported = 1;
 744                 }
 745         }
 746
 747         if (ir_supported && ir_ioapic_num != nr_ioapics) {
 748                 printk(KERN_WARNING
 749                        "Not all IO-APIC's listed under remapping hardware\n");
 750                 return -1;
 751         }
 752
 753         return ir_supported;
 754 }
 755
 756 void disable_intr_remapping(void)
 757 {
 758         struct dmar_drhd_unit *drhd;
 759         struct intel_iommu *iommu = NULL;
 760
 761         /*
 762          * Disable Interrupt-remapping for all the DRHD's now.
 763          */
 764         for_each_iommu(iommu, drhd) {
 765                 if (!ecap_ir_support(iommu->ecap))
 766                         continue;
 767
 768                 iommu_disable_intr_remapping(iommu);
 769         }
 770 }
 771
 772 int reenable_intr_remapping(int eim)
 773 {
 774         struct dmar_drhd_unit *drhd;
 775         int setup = 0;
 776         struct intel_iommu *iommu = NULL;
 777
 778         for_each_iommu(iommu, drhd)
 779                 if (iommu->qi)
 780                         dmar_reenable_qi(iommu);
 781
 782         /*
 783          * Setup Interrupt-remapping for all the DRHD's now.
 784          */
 785         for_each_iommu(iommu, drhd) {
 786                 if (!ecap_ir_support(iommu->ecap))
 787                         continue;
 788
 789                 /* Set up interrupt remapping for iommu.*/
 790                 iommu_set_intr_remapping(iommu, eim);
 791                 setup = 1;
 792         }
 793
 794         if (!setup)
 795                 goto error;
 796
 797         return 0;
 798
 799 error:
 800         /*
 801          * handle error condition gracefully here!
 802          */
 803         return -1;
 804 }
 805