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 struct irq_2_iommu {
  50         struct intel_iommu *iommu;
  51         u16 irte_index;
  52         u16 sub_handle;
  53         u8  irte_mask;
  54 };
  55
  56 #ifdef CONFIG_GENERIC_HARDIRQS
  57 static struct irq_2_iommu *get_one_free_irq_2_iommu(int node)
  58 {
  59         struct irq_2_iommu *iommu;
  60
  61         iommu = kzalloc_node(sizeof(*iommu), GFP_ATOMIC, node);
  62         printk(KERN_DEBUG "alloc irq_2_iommu on node %d\n", node);
  63
  64         return iommu;
  65 }
  66
  67 static struct irq_2_iommu *irq_2_iommu(unsigned int irq)
  68 {
  69         struct irq_desc *desc;
  70
  71         desc = irq_to_desc(irq);
  72
  73         if (WARN_ON_ONCE(!desc))
  74                 return NULL;
  75
  76         return desc->irq_2_iommu;
  77 }
  78
  79 static struct irq_2_iommu *irq_2_iommu_alloc(unsigned int irq)
  80 {
  81         struct irq_desc *desc;
  82         struct irq_2_iommu *irq_iommu;
  83
  84         desc = irq_to_desc(irq);
  85         if (!desc) {
  86                 printk(KERN_INFO "can not get irq_desc for %d\n", irq);
  87                 return NULL;
  88         }
  89
  90         irq_iommu = desc->irq_2_iommu;
  91
  92         if (!irq_iommu)
  93                 desc->irq_2_iommu = get_one_free_irq_2_iommu(irq_node(irq));
  94
  95         return desc->irq_2_iommu;
  96 }
  97
  98 #else /* !CONFIG_SPARSE_IRQ */
  99
 100 static struct irq_2_iommu irq_2_iommuX[NR_IRQS];
 101
 102 static struct irq_2_iommu *irq_2_iommu(unsigned int irq)
 103 {
 104         if (irq < nr_irqs)
 105                 return &irq_2_iommuX[irq];
 106
 107         return NULL;
 108 }
 109 static struct irq_2_iommu *irq_2_iommu_alloc(unsigned int irq)
 110 {
 111         return irq_2_iommu(irq);
 112 }
 113 #endif
 114
 115 static DEFINE_SPINLOCK(irq_2_ir_lock);
 116
 117 static struct irq_2_iommu *valid_irq_2_iommu(unsigned int irq)
 118 {
 119         struct irq_2_iommu *irq_iommu;
 120
 121         irq_iommu = irq_2_iommu(irq);
 122
 123         if (!irq_iommu)
 124                 return NULL;
 125
 126         if (!irq_iommu->iommu)
 127                 return NULL;
 128
 129         return irq_iommu;
 130 }
 131
 132 int irq_remapped(int irq)
 133 {
 134         return valid_irq_2_iommu(irq) != NULL;
 135 }
 136
 137 int get_irte(int irq, struct irte *entry)
 138 {
 139         int index;
 140         struct irq_2_iommu *irq_iommu;
 141         unsigned long flags;
 142
 143         if (!entry)
 144                 return -1;
 145
 146         spin_lock_irqsave(&irq_2_ir_lock, flags);
 147         irq_iommu = valid_irq_2_iommu(irq);
 148         if (!irq_iommu) {
 149                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 150                 return -1;
 151         }
 152
 153         index = irq_iommu->irte_index + irq_iommu->sub_handle;
 154         *entry = *(irq_iommu->iommu->ir_table->base + index);
 155
 156         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 157         return 0;
 158 }
 159
 160 int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
 161 {
 162         struct ir_table *table = iommu->ir_table;
 163         struct irq_2_iommu *irq_iommu;
 164         u16 index, start_index;
 165         unsigned int mask = 0;
 166         unsigned long flags;
 167         int i;
 168
 169         if (!count)
 170                 return -1;
 171
 172 #ifndef CONFIG_SPARSE_IRQ
 173         /* protect irq_2_iommu_alloc later */
 174         if (irq >= nr_irqs)
 175                 return -1;
 176 #endif
 177
 178         /*
 179          * start the IRTE search from index 0.
 180          */
 181         index = start_index = 0;
 182
 183         if (count > 1) {
 184                 count = __roundup_pow_of_two(count);
 185                 mask = ilog2(count);
 186         }
 187
 188         if (mask > ecap_max_handle_mask(iommu->ecap)) {
 189                 printk(KERN_ERR
 190                        "Requested mask %x exceeds the max invalidation handle"
 191                        " mask value %Lx\n", mask,
 192                        ecap_max_handle_mask(iommu->ecap));
 193                 return -1;
 194         }
 195
 196         spin_lock_irqsave(&irq_2_ir_lock, flags);
 197         do {
 198                 for (i = index; i < index + count; i++)
 199                         if  (table->base[i].present)
 200                                 break;
 201                 /* empty index found */
 202                 if (i == index + count)
 203                         break;
 204
 205                 index = (index + count) % INTR_REMAP_TABLE_ENTRIES;
 206
 207                 if (index == start_index) {
 208                         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 209                         printk(KERN_ERR "can't allocate an IRTE\n");
 210                         return -1;
 211                 }
 212         } while (1);
 213
 214         for (i = index; i < index + count; i++)
 215                 table->base[i].present = 1;
 216
 217         irq_iommu = irq_2_iommu_alloc(irq);
 218         if (!irq_iommu) {
 219                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 220                 printk(KERN_ERR "can't allocate irq_2_iommu\n");
 221                 return -1;
 222         }
 223
 224         irq_iommu->iommu = iommu;
 225         irq_iommu->irte_index =  index;
 226         irq_iommu->sub_handle = 0;
 227         irq_iommu->irte_mask = mask;
 228
 229         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 230
 231         return index;
 232 }
 233
 234 static int qi_flush_iec(struct intel_iommu *iommu, int index, int mask)
 235 {
 236         struct qi_desc desc;
 237
 238         desc.low = QI_IEC_IIDEX(index) | QI_IEC_TYPE | QI_IEC_IM(mask)
 239                    | QI_IEC_SELECTIVE;
 240         desc.high = 0;
 241
 242         return qi_submit_sync(&desc, iommu);
 243 }
 244
 245 int map_irq_to_irte_handle(int irq, u16 *sub_handle)
 246 {
 247         int index;
 248         struct irq_2_iommu *irq_iommu;
 249         unsigned long flags;
 250
 251         spin_lock_irqsave(&irq_2_ir_lock, flags);
 252         irq_iommu = valid_irq_2_iommu(irq);
 253         if (!irq_iommu) {
 254                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 255                 return -1;
 256         }
 257
 258         *sub_handle = irq_iommu->sub_handle;
 259         index = irq_iommu->irte_index;
 260         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 261         return index;
 262 }
 263
 264 int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subhandle)
 265 {
 266         struct irq_2_iommu *irq_iommu;
 267         unsigned long flags;
 268
 269         spin_lock_irqsave(&irq_2_ir_lock, flags);
 270
 271         irq_iommu = irq_2_iommu_alloc(irq);
 272
 273         if (!irq_iommu) {
 274                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 275                 printk(KERN_ERR "can't allocate irq_2_iommu\n");
 276                 return -1;
 277         }
 278
 279         irq_iommu->iommu = iommu;
 280         irq_iommu->irte_index = index;
 281         irq_iommu->sub_handle = subhandle;
 282         irq_iommu->irte_mask = 0;
 283
 284         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 285
 286         return 0;
 287 }
 288
 289 int clear_irte_irq(int irq, struct intel_iommu *iommu, u16 index)
 290 {
 291         struct irq_2_iommu *irq_iommu;
 292         unsigned long flags;
 293
 294         spin_lock_irqsave(&irq_2_ir_lock, flags);
 295         irq_iommu = valid_irq_2_iommu(irq);
 296         if (!irq_iommu) {
 297                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 298                 return -1;
 299         }
 300
 301         irq_iommu->iommu = NULL;
 302         irq_iommu->irte_index = 0;
 303         irq_iommu->sub_handle = 0;
 304         irq_2_iommu(irq)->irte_mask = 0;
 305
 306         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 307
 308         return 0;
 309 }
 310
 311 int modify_irte(int irq, struct irte *irte_modified)
 312 {
 313         int rc;
 314         int index;
 315         struct irte *irte;
 316         struct intel_iommu *iommu;
 317         struct irq_2_iommu *irq_iommu;
 318         unsigned long flags;
 319
 320         spin_lock_irqsave(&irq_2_ir_lock, flags);
 321         irq_iommu = valid_irq_2_iommu(irq);
 322         if (!irq_iommu) {
 323                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 324                 return -1;
 325         }
 326
 327         iommu = irq_iommu->iommu;
 328
 329         index = irq_iommu->irte_index + irq_iommu->sub_handle;
 330         irte = &iommu->ir_table->base[index];
 331
 332         set_64bit(&irte->low, irte_modified->low);
 333         set_64bit(&irte->high, irte_modified->high);
 334         __iommu_flush_cache(iommu, irte, sizeof(*irte));
 335
 336         rc = qi_flush_iec(iommu, index, 0);
 337         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 338
 339         return rc;
 340 }
 341
 342 int flush_irte(int irq)
 343 {
 344         int rc;
 345         int index;
 346         struct intel_iommu *iommu;
 347         struct irq_2_iommu *irq_iommu;
 348         unsigned long flags;
 349
 350         spin_lock_irqsave(&irq_2_ir_lock, flags);
 351         irq_iommu = valid_irq_2_iommu(irq);
 352         if (!irq_iommu) {
 353                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 354                 return -1;
 355         }
 356
 357         iommu = irq_iommu->iommu;
 358
 359         index = irq_iommu->irte_index + irq_iommu->sub_handle;
 360
 361         rc = qi_flush_iec(iommu, index, irq_iommu->irte_mask);
 362         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 363
 364         return rc;
 365 }
 366
 367 struct intel_iommu *map_hpet_to_ir(u8 hpet_id)
 368 {
 369         int i;
 370
 371         for (i = 0; i < MAX_HPET_TBS; i++)
 372                 if (ir_hpet[i].id == hpet_id)
 373                         return ir_hpet[i].iommu;
 374         return NULL;
 375 }
 376
 377 struct intel_iommu *map_ioapic_to_ir(int apic)
 378 {
 379         int i;
 380
 381         for (i = 0; i < MAX_IO_APICS; i++)
 382                 if (ir_ioapic[i].id == apic)
 383                         return ir_ioapic[i].iommu;
 384         return NULL;
 385 }
 386
 387 struct intel_iommu *map_dev_to_ir(struct pci_dev *dev)
 388 {
 389         struct dmar_drhd_unit *drhd;
 390
 391         drhd = dmar_find_matched_drhd_unit(dev);
 392         if (!drhd)
 393                 return NULL;
 394
 395         return drhd->iommu;
 396 }
 397
 398 static int clear_entries(struct irq_2_iommu *irq_iommu)
 399 {
 400         struct irte *start, *entry, *end;
 401         struct intel_iommu *iommu;
 402         int index;
 403
 404         if (irq_iommu->sub_handle)
 405                 return 0;
 406
 407         iommu = irq_iommu->iommu;
 408         index = irq_iommu->irte_index + irq_iommu->sub_handle;
 409
 410         start = iommu->ir_table->base + index;
 411         end = start + (1 << irq_iommu->irte_mask);
 412
 413         for (entry = start; entry < end; entry++) {
 414                 set_64bit(&entry->low, 0);
 415                 set_64bit(&entry->high, 0);
 416         }
 417
 418         return qi_flush_iec(iommu, index, irq_iommu->irte_mask);
 419 }
 420
 421 int free_irte(int irq)
 422 {
 423         int rc = 0;
 424         struct irq_2_iommu *irq_iommu;
 425         unsigned long flags;
 426
 427         spin_lock_irqsave(&irq_2_ir_lock, flags);
 428         irq_iommu = valid_irq_2_iommu(irq);
 429         if (!irq_iommu) {
 430                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 431                 return -1;
 432         }
 433
 434         rc = clear_entries(irq_iommu);
 435
 436         irq_iommu->iommu = NULL;
 437         irq_iommu->irte_index = 0;
 438         irq_iommu->sub_handle = 0;
 439         irq_iommu->irte_mask = 0;
 440
 441         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 442
 443         return rc;
 444 }
 445
 446 /*
 447  * source validation type
 448  */
 449 #define SVT_NO_VERIFY           0x0  /* no verification is required */
 450 #define SVT_VERIFY_SID_SQ       0x1  /* verify using SID and SQ fiels */
 451 #define SVT_VERIFY_BUS          0x2  /* verify bus of request-id */
 452
 453 /*
 454  * source-id qualifier
 455  */
 456 #define SQ_ALL_16       0x0  /* verify all 16 bits of request-id */
 457 #define SQ_13_IGNORE_1  0x1  /* verify most significant 13 bits, ignore
 458                               * the third least significant bit
 459                               */
 460 #define SQ_13_IGNORE_2  0x2  /* verify most significant 13 bits, ignore
 461                               * the second and third least significant bits
 462                               */
 463 #define SQ_13_IGNORE_3  0x3  /* verify most significant 13 bits, ignore
 464                               * the least three significant bits
 465                               */
 466
 467 /*
 468  * set SVT, SQ and SID fields of irte to verify
 469  * source ids of interrupt requests
 470  */
 471 static void set_irte_sid(struct irte *irte, unsigned int svt,
 472                          unsigned int sq, unsigned int sid)
 473 {
 474         if (disable_sourceid_checking)
 475                 svt = SVT_NO_VERIFY;
 476         irte->svt = svt;
 477         irte->sq = sq;
 478         irte->sid = sid;
 479 }
 480
 481 int set_ioapic_sid(struct irte *irte, int apic)
 482 {
 483         int i;
 484         u16 sid = 0;
 485
 486         if (!irte)
 487                 return -1;
 488
 489         for (i = 0; i < MAX_IO_APICS; i++) {
 490                 if (ir_ioapic[i].id == apic) {
 491                         sid = (ir_ioapic[i].bus << 8) | ir_ioapic[i].devfn;
 492                         break;
 493                 }
 494         }
 495
 496         if (sid == 0) {
 497                 pr_warning("Failed to set source-id of IOAPIC (%d)\n", apic);
 498                 return -1;
 499         }
 500
 501         set_irte_sid(irte, 1, 0, sid);
 502
 503         return 0;
 504 }
 505
 506 int set_hpet_sid(struct irte *irte, u8 id)
 507 {
 508         int i;
 509         u16 sid = 0;
 510
 511         if (!irte)
 512                 return -1;
 513
 514         for (i = 0; i < MAX_HPET_TBS; i++) {
 515                 if (ir_hpet[i].id == id) {
 516                         sid = (ir_hpet[i].bus << 8) | ir_hpet[i].devfn;
 517                         break;
 518                 }
 519         }
 520
 521         if (sid == 0) {
 522                 pr_warning("Failed to set source-id of HPET block (%d)\n", id);
 523                 return -1;
 524         }
 525
 526         /*
 527          * Should really use SQ_ALL_16. Some platforms are broken.
 528          * While we figure out the right quirks for these broken platforms, use
 529          * SQ_13_IGNORE_3 for now.
 530          */
 531         set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_13_IGNORE_3, sid);
 532
 533         return 0;
 534 }
 535
 536 int set_msi_sid(struct irte *irte, struct pci_dev *dev)
 537 {
 538         struct pci_dev *bridge;
 539
 540         if (!irte || !dev)
 541                 return -1;
 542
 543         /* PCIe device or Root Complex integrated PCI device */
 544         if (pci_is_pcie(dev) || !dev->bus->parent) {
 545                 set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_ALL_16,
 546                              (dev->bus->number << 8) | dev->devfn);
 547                 return 0;
 548         }
 549
 550         bridge = pci_find_upstream_pcie_bridge(dev);
 551         if (bridge) {
 552                 if (pci_is_pcie(bridge))/* this is a PCIe-to-PCI/PCIX bridge */
 553                         set_irte_sid(irte, SVT_VERIFY_BUS, SQ_ALL_16,
 554                                 (bridge->bus->number << 8) | dev->bus->number);
 555                 else /* this is a legacy PCI bridge */
 556                         set_irte_sid(irte, SVT_VERIFY_SID_SQ, SQ_ALL_16,
 557                                 (bridge->bus->number << 8) | bridge->devfn);
 558         }
 559
 560         return 0;
 561 }
 562
 563 static void iommu_set_intr_remapping(struct intel_iommu *iommu, int mode)
 564 {
 565         u64 addr;
 566         u32 sts;
 567         unsigned long flags;
 568
 569         addr = virt_to_phys((void *)iommu->ir_table->base);
 570
 571         spin_lock_irqsave(&iommu->register_lock, flags);
 572
 573         dmar_writeq(iommu->reg + DMAR_IRTA_REG,
 574                     (addr) | IR_X2APIC_MODE(mode) | INTR_REMAP_TABLE_REG_SIZE);
 575
 576         /* Set interrupt-remapping table pointer */
 577         iommu->gcmd |= DMA_GCMD_SIRTP;
 578         writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
 579
 580         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 581                       readl, (sts & DMA_GSTS_IRTPS), sts);
 582         spin_unlock_irqrestore(&iommu->register_lock, flags);
 583
 584         /*
 585          * global invalidation of interrupt entry cache before enabling
 586          * interrupt-remapping.
 587          */
 588         qi_global_iec(iommu);
 589
 590         spin_lock_irqsave(&iommu->register_lock, flags);
 591
 592         /* Enable interrupt-remapping */
 593         iommu->gcmd |= DMA_GCMD_IRE;
 594         writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
 595
 596         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 597                       readl, (sts & DMA_GSTS_IRES), sts);
 598
 599         spin_unlock_irqrestore(&iommu->register_lock, flags);
 600 }
 601
 602
 603 static int setup_intr_remapping(struct intel_iommu *iommu, int mode)
 604 {
 605         struct ir_table *ir_table;
 606         struct page *pages;
 607
 608         ir_table = iommu->ir_table = kzalloc(sizeof(struct ir_table),
 609                                              GFP_ATOMIC);
 610
 611         if (!iommu->ir_table)
 612                 return -ENOMEM;
 613
 614         pages = alloc_pages_node(iommu->node, GFP_ATOMIC | __GFP_ZERO,
 615                                  INTR_REMAP_PAGE_ORDER);
 616
 617         if (!pages) {
 618                 printk(KERN_ERR "failed to allocate pages of order %d\n",
 619                        INTR_REMAP_PAGE_ORDER);
 620                 kfree(iommu->ir_table);
 621                 return -ENOMEM;
 622         }
 623
 624         ir_table->base = page_address(pages);
 625
 626         iommu_set_intr_remapping(iommu, mode);
 627         return 0;
 628 }
 629
 630 /*
 631  * Disable Interrupt Remapping.
 632  */
 633 static void iommu_disable_intr_remapping(struct intel_iommu *iommu)
 634 {
 635         unsigned long flags;
 636         u32 sts;
 637
 638         if (!ecap_ir_support(iommu->ecap))
 639                 return;
 640
 641         /*
 642          * global invalidation of interrupt entry cache before disabling
 643          * interrupt-remapping.
 644          */
 645         qi_global_iec(iommu);
 646
 647         spin_lock_irqsave(&iommu->register_lock, flags);
 648
 649         sts = dmar_readq(iommu->reg + DMAR_GSTS_REG);
 650         if (!(sts & DMA_GSTS_IRES))
 651                 goto end;
 652
 653         iommu->gcmd &= ~DMA_GCMD_IRE;
 654         writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
 655
 656         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 657                       readl, !(sts & DMA_GSTS_IRES), sts);
 658
 659 end:
 660         spin_unlock_irqrestore(&iommu->register_lock, flags);
 661 }
 662
 663 int __init intr_remapping_supported(void)
 664 {
 665         struct dmar_drhd_unit *drhd;
 666
 667         if (disable_intremap)
 668                 return 0;
 669
 670         if (!dmar_ir_support())
 671                 return 0;
 672
 673         for_each_drhd_unit(drhd) {
 674                 struct intel_iommu *iommu = drhd->iommu;
 675
 676                 if (!ecap_ir_support(iommu->ecap))
 677                         return 0;
 678         }
 679
 680         return 1;
 681 }
 682
 683 int __init enable_intr_remapping(int eim)
 684 {
 685         struct dmar_drhd_unit *drhd;
 686         int setup = 0;
 687
 688         if (parse_ioapics_under_ir() != 1) {
 689                 printk(KERN_INFO "Not enable interrupt remapping\n");
 690                 return -1;
 691         }
 692
 693         for_each_drhd_unit(drhd) {
 694                 struct intel_iommu *iommu = drhd->iommu;
 695
 696                 /*
 697                  * If the queued invalidation is already initialized,
 698                  * shouldn't disable it.
 699                  */
 700                 if (iommu->qi)
 701                         continue;
 702
 703                 /*
 704                  * Clear previous faults.
 705                  */
 706                 dmar_fault(-1, iommu);
 707
 708                 /*
 709                  * Disable intr remapping and queued invalidation, if already
 710                  * enabled prior to OS handover.
 711                  */
 712                 iommu_disable_intr_remapping(iommu);
 713
 714                 dmar_disable_qi(iommu);
 715         }
 716
 717         /*
 718          * check for the Interrupt-remapping support
 719          */
 720         for_each_drhd_unit(drhd) {
 721                 struct intel_iommu *iommu = drhd->iommu;
 722
 723                 if (!ecap_ir_support(iommu->ecap))
 724                         continue;
 725
 726                 if (eim && !ecap_eim_support(iommu->ecap)) {
 727                         printk(KERN_INFO "DRHD %Lx: EIM not supported by DRHD, "
 728                                " ecap %Lx\n", drhd->reg_base_addr, iommu->ecap);
 729                         return -1;
 730                 }
 731         }
 732
 733         /*
 734          * Enable queued invalidation for all the DRHD's.
 735          */
 736         for_each_drhd_unit(drhd) {
 737                 int ret;
 738                 struct intel_iommu *iommu = drhd->iommu;
 739                 ret = dmar_enable_qi(iommu);
 740
 741                 if (ret) {
 742                         printk(KERN_ERR "DRHD %Lx: failed to enable queued, "
 743                                " invalidation, ecap %Lx, ret %d\n",
 744                                drhd->reg_base_addr, iommu->ecap, ret);
 745                         return -1;
 746                 }
 747         }
 748
 749         /*
 750          * Setup Interrupt-remapping for all the DRHD's now.
 751          */
 752         for_each_drhd_unit(drhd) {
 753                 struct intel_iommu *iommu = drhd->iommu;
 754
 755                 if (!ecap_ir_support(iommu->ecap))
 756                         continue;
 757
 758                 if (setup_intr_remapping(iommu, eim))
 759                         goto error;
 760
 761                 setup = 1;
 762         }
 763
 764         if (!setup)
 765                 goto error;
 766
 767         intr_remapping_enabled = 1;
 768
 769         return 0;
 770
 771 error:
 772         /*
 773          * handle error condition gracefully here!
 774          */
 775         return -1;
 776 }
 777
 778 static void ir_parse_one_hpet_scope(struct acpi_dmar_device_scope *scope,
 779                                       struct intel_iommu *iommu)
 780 {
 781         struct acpi_dmar_pci_path *path;
 782         u8 bus;
 783         int count;
 784
 785         bus = scope->bus;
 786         path = (struct acpi_dmar_pci_path *)(scope + 1);
 787         count = (scope->length - sizeof(struct acpi_dmar_device_scope))
 788                 / sizeof(struct acpi_dmar_pci_path);
 789
 790         while (--count > 0) {
 791                 /*
 792                  * Access PCI directly due to the PCI
 793                  * subsystem isn't initialized yet.
 794                  */
 795                 bus = read_pci_config_byte(bus, path->dev, path->fn,
 796                                            PCI_SECONDARY_BUS);
 797                 path++;
 798         }
 799         ir_hpet[ir_hpet_num].bus   = bus;
 800         ir_hpet[ir_hpet_num].devfn = PCI_DEVFN(path->dev, path->fn);
 801         ir_hpet[ir_hpet_num].iommu = iommu;
 802         ir_hpet[ir_hpet_num].id    = scope->enumeration_id;
 803         ir_hpet_num++;
 804 }
 805
 806 static void ir_parse_one_ioapic_scope(struct acpi_dmar_device_scope *scope,
 807                                       struct intel_iommu *iommu)
 808 {
 809         struct acpi_dmar_pci_path *path;
 810         u8 bus;
 811         int count;
 812
 813         bus = scope->bus;
 814         path = (struct acpi_dmar_pci_path *)(scope + 1);
 815         count = (scope->length - sizeof(struct acpi_dmar_device_scope))
 816                 / sizeof(struct acpi_dmar_pci_path);
 817
 818         while (--count > 0) {
 819                 /*
 820                  * Access PCI directly due to the PCI
 821                  * subsystem isn't initialized yet.
 822                  */
 823                 bus = read_pci_config_byte(bus, path->dev, path->fn,
 824                                            PCI_SECONDARY_BUS);
 825                 path++;
 826         }
 827
 828         ir_ioapic[ir_ioapic_num].bus   = bus;
 829         ir_ioapic[ir_ioapic_num].devfn = PCI_DEVFN(path->dev, path->fn);
 830         ir_ioapic[ir_ioapic_num].iommu = iommu;
 831         ir_ioapic[ir_ioapic_num].id    = scope->enumeration_id;
 832         ir_ioapic_num++;
 833 }
 834
 835 static int ir_parse_ioapic_hpet_scope(struct acpi_dmar_header *header,
 836                                       struct intel_iommu *iommu)
 837 {
 838         struct acpi_dmar_hardware_unit *drhd;
 839         struct acpi_dmar_device_scope *scope;
 840         void *start, *end;
 841
 842         drhd = (struct acpi_dmar_hardware_unit *)header;
 843
 844         start = (void *)(drhd + 1);
 845         end = ((void *)drhd) + header->length;
 846
 847         while (start < end) {
 848                 scope = start;
 849                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_IOAPIC) {
 850                         if (ir_ioapic_num == MAX_IO_APICS) {
 851                                 printk(KERN_WARNING "Exceeded Max IO APICS\n");
 852                                 return -1;
 853                         }
 854
 855                         printk(KERN_INFO "IOAPIC id %d under DRHD base "
 856                                " 0x%Lx IOMMU %d\n", scope->enumeration_id,
 857                                drhd->address, iommu->seq_id);
 858
 859                         ir_parse_one_ioapic_scope(scope, iommu);
 860                 } else if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_HPET) {
 861                         if (ir_hpet_num == MAX_HPET_TBS) {
 862                                 printk(KERN_WARNING "Exceeded Max HPET blocks\n");
 863                                 return -1;
 864                         }
 865
 866                         printk(KERN_INFO "HPET id %d under DRHD base"
 867                                " 0x%Lx\n", scope->enumeration_id,
 868                                drhd->address);
 869
 870                         ir_parse_one_hpet_scope(scope, iommu);
 871                 }
 872                 start += scope->length;
 873         }
 874
 875         return 0;
 876 }
 877
 878 /*
 879  * Finds the assocaition between IOAPIC's and its Interrupt-remapping
 880  * hardware unit.
 881  */
 882 int __init parse_ioapics_under_ir(void)
 883 {
 884         struct dmar_drhd_unit *drhd;
 885         int ir_supported = 0;
 886
 887         for_each_drhd_unit(drhd) {
 888                 struct intel_iommu *iommu = drhd->iommu;
 889
 890                 if (ecap_ir_support(iommu->ecap)) {
 891                         if (ir_parse_ioapic_hpet_scope(drhd->hdr, iommu))
 892                                 return -1;
 893
 894                         ir_supported = 1;
 895                 }
 896         }
 897
 898         if (ir_supported && ir_ioapic_num != nr_ioapics) {
 899                 printk(KERN_WARNING
 900                        "Not all IO-APIC's listed under remapping hardware\n");
 901                 return -1;
 902         }
 903
 904         return ir_supported;
 905 }
 906
 907 void disable_intr_remapping(void)
 908 {
 909         struct dmar_drhd_unit *drhd;
 910         struct intel_iommu *iommu = NULL;
 911
 912         /*
 913          * Disable Interrupt-remapping for all the DRHD's now.
 914          */
 915         for_each_iommu(iommu, drhd) {
 916                 if (!ecap_ir_support(iommu->ecap))
 917                         continue;
 918
 919                 iommu_disable_intr_remapping(iommu);
 920         }
 921 }
 922
 923 int reenable_intr_remapping(int eim)
 924 {
 925         struct dmar_drhd_unit *drhd;
 926         int setup = 0;
 927         struct intel_iommu *iommu = NULL;
 928
 929         for_each_iommu(iommu, drhd)
 930                 if (iommu->qi)
 931                         dmar_reenable_qi(iommu);
 932
 933         /*
 934          * Setup Interrupt-remapping for all the DRHD's now.
 935          */
 936         for_each_iommu(iommu, drhd) {
 937                 if (!ecap_ir_support(iommu->ecap))
 938                         continue;
 939
 940                 /* Set up interrupt remapping for iommu.*/
 941                 iommu_set_intr_remapping(iommu, eim);
 942                 setup = 1;
 943         }
 944
 945         if (!setup)
 946                 goto error;
 947
 948         return 0;
 949
 950 error:
 951         /*
 952          * handle error condition gracefully here!
 953          */
 954         return -1;
 955 }
 956