drivers/pci/intr_remapping.c

   1 #include <linux/interrupt.h>
   2 #include <linux/dmar.h>
   3 #include <linux/spinlock.h>
   4 #include <linux/jiffies.h>
   5 #include <linux/pci.h>
   6 #include <linux/irq.h>
   7 #include <asm/io_apic.h>
   8 #include <asm/smp.h>
   9 #include <asm/cpu.h>
  10 #include <linux/intel-iommu.h>
  11 #include "intr_remapping.h"
  12 #include <acpi/acpi.h>
  13
  14 static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
  15 static int ir_ioapic_num;
  16 int intr_remapping_enabled;
  17
  18 struct irq_2_iommu {
  19         struct intel_iommu *iommu;
  20         u16 irte_index;
  21         u16 sub_handle;
  22         u8  irte_mask;
  23 };
  24
  25 #ifdef CONFIG_GENERIC_HARDIRQS
  26 static struct irq_2_iommu *get_one_free_irq_2_iommu(int cpu)
  27 {
  28         struct irq_2_iommu *iommu;
  29         int node;
  30
  31         node = cpu_to_node(cpu);
  32
  33         iommu = kzalloc_node(sizeof(*iommu), GFP_ATOMIC, node);
  34         printk(KERN_DEBUG "alloc irq_2_iommu on cpu %d node %d\n", cpu, node);
  35
  36         return iommu;
  37 }
  38
  39 static struct irq_2_iommu *irq_2_iommu(unsigned int irq)
  40 {
  41         struct irq_desc *desc;
  42
  43         desc = irq_to_desc(irq);
  44
  45         if (WARN_ON_ONCE(!desc))
  46                 return NULL;
  47
  48         return desc->irq_2_iommu;
  49 }
  50
  51 static struct irq_2_iommu *irq_2_iommu_alloc_cpu(unsigned int irq, int cpu)
  52 {
  53         struct irq_desc *desc;
  54         struct irq_2_iommu *irq_iommu;
  55
  56         /*
  57          * alloc irq desc if not allocated already.
  58          */
  59         desc = irq_to_desc_alloc_cpu(irq, cpu);
  60         if (!desc) {
  61                 printk(KERN_INFO "can not get irq_desc for %d\n", irq);
  62                 return NULL;
  63         }
  64
  65         irq_iommu = desc->irq_2_iommu;
  66
  67         if (!irq_iommu)
  68                 desc->irq_2_iommu = get_one_free_irq_2_iommu(cpu);
  69
  70         return desc->irq_2_iommu;
  71 }
  72
  73 static struct irq_2_iommu *irq_2_iommu_alloc(unsigned int irq)
  74 {
  75         return irq_2_iommu_alloc_cpu(irq, boot_cpu_id);
  76 }
  77
  78 #else /* !CONFIG_SPARSE_IRQ */
  79
  80 static struct irq_2_iommu irq_2_iommuX[NR_IRQS];
  81
  82 static struct irq_2_iommu *irq_2_iommu(unsigned int irq)
  83 {
  84         if (irq < nr_irqs)
  85                 return &irq_2_iommuX[irq];
  86
  87         return NULL;
  88 }
  89 static struct irq_2_iommu *irq_2_iommu_alloc(unsigned int irq)
  90 {
  91         return irq_2_iommu(irq);
  92 }
  93 #endif
  94
  95 static DEFINE_SPINLOCK(irq_2_ir_lock);
  96
  97 static struct irq_2_iommu *valid_irq_2_iommu(unsigned int irq)
  98 {
  99         struct irq_2_iommu *irq_iommu;
 100
 101         irq_iommu = irq_2_iommu(irq);
 102
 103         if (!irq_iommu)
 104                 return NULL;
 105
 106         if (!irq_iommu->iommu)
 107                 return NULL;
 108
 109         return irq_iommu;
 110 }
 111
 112 int irq_remapped(int irq)
 113 {
 114         return valid_irq_2_iommu(irq) != NULL;
 115 }
 116
 117 int get_irte(int irq, struct irte *entry)
 118 {
 119         int index;
 120         struct irq_2_iommu *irq_iommu;
 121         unsigned long flags;
 122
 123         if (!entry)
 124                 return -1;
 125
 126         spin_lock_irqsave(&irq_2_ir_lock, flags);
 127         irq_iommu = valid_irq_2_iommu(irq);
 128         if (!irq_iommu) {
 129                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 130                 return -1;
 131         }
 132
 133         index = irq_iommu->irte_index + irq_iommu->sub_handle;
 134         *entry = *(irq_iommu->iommu->ir_table->base + index);
 135
 136         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 137         return 0;
 138 }
 139
 140 int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
 141 {
 142         struct ir_table *table = iommu->ir_table;
 143         struct irq_2_iommu *irq_iommu;
 144         u16 index, start_index;
 145         unsigned int mask = 0;
 146         unsigned long flags;
 147         int i;
 148
 149         if (!count)
 150                 return -1;
 151
 152 #ifndef CONFIG_SPARSE_IRQ
 153         /* protect irq_2_iommu_alloc later */
 154         if (irq >= nr_irqs)
 155                 return -1;
 156 #endif
 157
 158         /*
 159          * start the IRTE search from index 0.
 160          */
 161         index = start_index = 0;
 162
 163         if (count > 1) {
 164                 count = __roundup_pow_of_two(count);
 165                 mask = ilog2(count);
 166         }
 167
 168         if (mask > ecap_max_handle_mask(iommu->ecap)) {
 169                 printk(KERN_ERR
 170                        "Requested mask %x exceeds the max invalidation handle"
 171                        " mask value %Lx\n", mask,
 172                        ecap_max_handle_mask(iommu->ecap));
 173                 return -1;
 174         }
 175
 176         spin_lock_irqsave(&irq_2_ir_lock, flags);
 177         do {
 178                 for (i = index; i < index + count; i++)
 179                         if  (table->base[i].present)
 180                                 break;
 181                 /* empty index found */
 182                 if (i == index + count)
 183                         break;
 184
 185                 index = (index + count) % INTR_REMAP_TABLE_ENTRIES;
 186
 187                 if (index == start_index) {
 188                         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 189                         printk(KERN_ERR "can't allocate an IRTE\n");
 190                         return -1;
 191                 }
 192         } while (1);
 193
 194         for (i = index; i < index + count; i++)
 195                 table->base[i].present = 1;
 196
 197         irq_iommu = irq_2_iommu_alloc(irq);
 198         if (!irq_iommu) {
 199                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 200                 printk(KERN_ERR "can't allocate irq_2_iommu\n");
 201                 return -1;
 202         }
 203
 204         irq_iommu->iommu = iommu;
 205         irq_iommu->irte_index =  index;
 206         irq_iommu->sub_handle = 0;
 207         irq_iommu->irte_mask = mask;
 208
 209         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 210
 211         return index;
 212 }
 213
 214 static int qi_flush_iec(struct intel_iommu *iommu, int index, int mask)
 215 {
 216         struct qi_desc desc;
 217
 218         desc.low = QI_IEC_IIDEX(index) | QI_IEC_TYPE | QI_IEC_IM(mask)
 219                    | QI_IEC_SELECTIVE;
 220         desc.high = 0;
 221
 222         return qi_submit_sync(&desc, iommu);
 223 }
 224
 225 int map_irq_to_irte_handle(int irq, u16 *sub_handle)
 226 {
 227         int index;
 228         struct irq_2_iommu *irq_iommu;
 229         unsigned long flags;
 230
 231         spin_lock_irqsave(&irq_2_ir_lock, flags);
 232         irq_iommu = valid_irq_2_iommu(irq);
 233         if (!irq_iommu) {
 234                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 235                 return -1;
 236         }
 237
 238         *sub_handle = irq_iommu->sub_handle;
 239         index = irq_iommu->irte_index;
 240         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 241         return index;
 242 }
 243
 244 int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subhandle)
 245 {
 246         struct irq_2_iommu *irq_iommu;
 247         unsigned long flags;
 248
 249         spin_lock_irqsave(&irq_2_ir_lock, flags);
 250
 251         irq_iommu = irq_2_iommu_alloc(irq);
 252
 253         if (!irq_iommu) {
 254                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 255                 printk(KERN_ERR "can't allocate irq_2_iommu\n");
 256                 return -1;
 257         }
 258
 259         irq_iommu->iommu = iommu;
 260         irq_iommu->irte_index = index;
 261         irq_iommu->sub_handle = subhandle;
 262         irq_iommu->irte_mask = 0;
 263
 264         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 265
 266         return 0;
 267 }
 268
 269 int clear_irte_irq(int irq, struct intel_iommu *iommu, u16 index)
 270 {
 271         struct irq_2_iommu *irq_iommu;
 272         unsigned long flags;
 273
 274         spin_lock_irqsave(&irq_2_ir_lock, flags);
 275         irq_iommu = valid_irq_2_iommu(irq);
 276         if (!irq_iommu) {
 277                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 278                 return -1;
 279         }
 280
 281         irq_iommu->iommu = NULL;
 282         irq_iommu->irte_index = 0;
 283         irq_iommu->sub_handle = 0;
 284         irq_2_iommu(irq)->irte_mask = 0;
 285
 286         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 287
 288         return 0;
 289 }
 290
 291 int modify_irte(int irq, struct irte *irte_modified)
 292 {
 293         int rc;
 294         int index;
 295         struct irte *irte;
 296         struct intel_iommu *iommu;
 297         struct irq_2_iommu *irq_iommu;
 298         unsigned long flags;
 299
 300         spin_lock_irqsave(&irq_2_ir_lock, flags);
 301         irq_iommu = valid_irq_2_iommu(irq);
 302         if (!irq_iommu) {
 303                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 304                 return -1;
 305         }
 306
 307         iommu = irq_iommu->iommu;
 308
 309         index = irq_iommu->irte_index + irq_iommu->sub_handle;
 310         irte = &iommu->ir_table->base[index];
 311
 312         set_64bit((unsigned long *)irte, irte_modified->low);
 313         __iommu_flush_cache(iommu, irte, sizeof(*irte));
 314
 315         rc = qi_flush_iec(iommu, index, 0);
 316         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 317
 318         return rc;
 319 }
 320
 321 int flush_irte(int irq)
 322 {
 323         int rc;
 324         int index;
 325         struct intel_iommu *iommu;
 326         struct irq_2_iommu *irq_iommu;
 327         unsigned long flags;
 328
 329         spin_lock_irqsave(&irq_2_ir_lock, flags);
 330         irq_iommu = valid_irq_2_iommu(irq);
 331         if (!irq_iommu) {
 332                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 333                 return -1;
 334         }
 335
 336         iommu = irq_iommu->iommu;
 337
 338         index = irq_iommu->irte_index + irq_iommu->sub_handle;
 339
 340         rc = qi_flush_iec(iommu, index, irq_iommu->irte_mask);
 341         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 342
 343         return rc;
 344 }
 345
 346 struct intel_iommu *map_ioapic_to_ir(int apic)
 347 {
 348         int i;
 349
 350         for (i = 0; i < MAX_IO_APICS; i++)
 351                 if (ir_ioapic[i].id == apic)
 352                         return ir_ioapic[i].iommu;
 353         return NULL;
 354 }
 355
 356 struct intel_iommu *map_dev_to_ir(struct pci_dev *dev)
 357 {
 358         struct dmar_drhd_unit *drhd;
 359
 360         drhd = dmar_find_matched_drhd_unit(dev);
 361         if (!drhd)
 362                 return NULL;
 363
 364         return drhd->iommu;
 365 }
 366
 367 int free_irte(int irq)
 368 {
 369         int rc = 0;
 370         int index, i;
 371         struct irte *irte;
 372         struct intel_iommu *iommu;
 373         struct irq_2_iommu *irq_iommu;
 374         unsigned long flags;
 375
 376         spin_lock_irqsave(&irq_2_ir_lock, flags);
 377         irq_iommu = valid_irq_2_iommu(irq);
 378         if (!irq_iommu) {
 379                 spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 380                 return -1;
 381         }
 382
 383         iommu = irq_iommu->iommu;
 384
 385         index = irq_iommu->irte_index + irq_iommu->sub_handle;
 386         irte = &iommu->ir_table->base[index];
 387
 388         if (!irq_iommu->sub_handle) {
 389                 for (i = 0; i < (1 << irq_iommu->irte_mask); i++)
 390                         set_64bit((unsigned long *)(irte + i), 0);
 391                 rc = qi_flush_iec(iommu, index, irq_iommu->irte_mask);
 392         }
 393
 394         irq_iommu->iommu = NULL;
 395         irq_iommu->irte_index = 0;
 396         irq_iommu->sub_handle = 0;
 397         irq_iommu->irte_mask = 0;
 398
 399         spin_unlock_irqrestore(&irq_2_ir_lock, flags);
 400
 401         return rc;
 402 }
 403
 404 static void iommu_set_intr_remapping(struct intel_iommu *iommu, int mode)
 405 {
 406         u64 addr;
 407         u32 cmd, sts;
 408         unsigned long flags;
 409
 410         addr = virt_to_phys((void *)iommu->ir_table->base);
 411
 412         spin_lock_irqsave(&iommu->register_lock, flags);
 413
 414         dmar_writeq(iommu->reg + DMAR_IRTA_REG,
 415                     (addr) | IR_X2APIC_MODE(mode) | INTR_REMAP_TABLE_REG_SIZE);
 416
 417         /* Set interrupt-remapping table pointer */
 418         cmd = iommu->gcmd | DMA_GCMD_SIRTP;
 419         iommu->gcmd |= DMA_GCMD_SIRTP;
 420         writel(cmd, iommu->reg + DMAR_GCMD_REG);
 421
 422         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 423                       readl, (sts & DMA_GSTS_IRTPS), sts);
 424         spin_unlock_irqrestore(&iommu->register_lock, flags);
 425
 426         /*
 427          * global invalidation of interrupt entry cache before enabling
 428          * interrupt-remapping.
 429          */
 430         qi_global_iec(iommu);
 431
 432         spin_lock_irqsave(&iommu->register_lock, flags);
 433
 434         /* Enable interrupt-remapping */
 435         cmd = iommu->gcmd | DMA_GCMD_IRE;
 436         iommu->gcmd |= DMA_GCMD_IRE;
 437         writel(cmd, iommu->reg + DMAR_GCMD_REG);
 438
 439         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 440                       readl, (sts & DMA_GSTS_IRES), sts);
 441
 442         spin_unlock_irqrestore(&iommu->register_lock, flags);
 443 }
 444
 445
 446 static int setup_intr_remapping(struct intel_iommu *iommu, int mode)
 447 {
 448         struct ir_table *ir_table;
 449         struct page *pages;
 450
 451         ir_table = iommu->ir_table = kzalloc(sizeof(struct ir_table),
 452                                              GFP_ATOMIC);
 453
 454         if (!iommu->ir_table)
 455                 return -ENOMEM;
 456
 457         pages = alloc_pages(GFP_ATOMIC | __GFP_ZERO, INTR_REMAP_PAGE_ORDER);
 458
 459         if (!pages) {
 460                 printk(KERN_ERR "failed to allocate pages of order %d\n",
 461                        INTR_REMAP_PAGE_ORDER);
 462                 kfree(iommu->ir_table);
 463                 return -ENOMEM;
 464         }
 465
 466         ir_table->base = page_address(pages);
 467
 468         iommu_set_intr_remapping(iommu, mode);
 469         return 0;
 470 }
 471
 472 /*
 473  * Disable Interrupt Remapping.
 474  */
 475 static void iommu_disable_intr_remapping(struct intel_iommu *iommu)
 476 {
 477         unsigned long flags;
 478         u32 sts;
 479
 480         if (!ecap_ir_support(iommu->ecap))
 481                 return;
 482
 483         /*
 484          * global invalidation of interrupt entry cache before disabling
 485          * interrupt-remapping.
 486          */
 487         qi_global_iec(iommu);
 488
 489         spin_lock_irqsave(&iommu->register_lock, flags);
 490
 491         sts = dmar_readq(iommu->reg + DMAR_GSTS_REG);
 492         if (!(sts & DMA_GSTS_IRES))
 493                 goto end;
 494
 495         iommu->gcmd &= ~DMA_GCMD_IRE;
 496         writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
 497
 498         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 499                       readl, !(sts & DMA_GSTS_IRES), sts);
 500
 501 end:
 502         spin_unlock_irqrestore(&iommu->register_lock, flags);
 503 }
 504
 505 int __init intr_remapping_supported(void)
 506 {
 507         struct dmar_drhd_unit *drhd;
 508
 509         for_each_drhd_unit(drhd) {
 510                 struct intel_iommu *iommu = drhd->iommu;
 511
 512                 if (!ecap_ir_support(iommu->ecap))
 513                         return 0;
 514         }
 515
 516         return 1;
 517 }
 518
 519 int __init enable_intr_remapping(int eim)
 520 {
 521         struct dmar_drhd_unit *drhd;
 522         int setup = 0;
 523
 524         for_each_drhd_unit(drhd) {
 525                 struct intel_iommu *iommu = drhd->iommu;
 526
 527                 /*
 528                  * If the queued invalidation is already initialized,
 529                  * shouldn't disable it.
 530                  */
 531                 if (iommu->qi)
 532                         continue;
 533
 534                 /*
 535                  * Clear previous faults.
 536                  */
 537                 dmar_fault(-1, iommu);
 538
 539                 /*
 540                  * Disable intr remapping and queued invalidation, if already
 541                  * enabled prior to OS handover.
 542                  */
 543                 iommu_disable_intr_remapping(iommu);
 544
 545                 dmar_disable_qi(iommu);
 546         }
 547
 548         /*
 549          * check for the Interrupt-remapping support
 550          */
 551         for_each_drhd_unit(drhd) {
 552                 struct intel_iommu *iommu = drhd->iommu;
 553
 554                 if (!ecap_ir_support(iommu->ecap))
 555                         continue;
 556
 557                 if (eim && !ecap_eim_support(iommu->ecap)) {
 558                         printk(KERN_INFO "DRHD %Lx: EIM not supported by DRHD, "
 559                                " ecap %Lx\n", drhd->reg_base_addr, iommu->ecap);
 560                         return -1;
 561                 }
 562         }
 563
 564         /*
 565          * Enable queued invalidation for all the DRHD's.
 566          */
 567         for_each_drhd_unit(drhd) {
 568                 int ret;
 569                 struct intel_iommu *iommu = drhd->iommu;
 570                 ret = dmar_enable_qi(iommu);
 571
 572                 if (ret) {
 573                         printk(KERN_ERR "DRHD %Lx: failed to enable queued, "
 574                                " invalidation, ecap %Lx, ret %d\n",
 575                                drhd->reg_base_addr, iommu->ecap, ret);
 576                         return -1;
 577                 }
 578         }
 579
 580         /*
 581          * Setup Interrupt-remapping for all the DRHD's now.
 582          */
 583         for_each_drhd_unit(drhd) {
 584                 struct intel_iommu *iommu = drhd->iommu;
 585
 586                 if (!ecap_ir_support(iommu->ecap))
 587                         continue;
 588
 589                 if (setup_intr_remapping(iommu, eim))
 590                         goto error;
 591
 592                 setup = 1;
 593         }
 594
 595         if (!setup)
 596                 goto error;
 597
 598         intr_remapping_enabled = 1;
 599
 600         return 0;
 601
 602 error:
 603         /*
 604          * handle error condition gracefully here!
 605          */
 606         return -1;
 607 }
 608
 609 static int ir_parse_ioapic_scope(struct acpi_dmar_header *header,
 610                                  struct intel_iommu *iommu)
 611 {
 612         struct acpi_dmar_hardware_unit *drhd;
 613         struct acpi_dmar_device_scope *scope;
 614         void *start, *end;
 615
 616         drhd = (struct acpi_dmar_hardware_unit *)header;
 617
 618         start = (void *)(drhd + 1);
 619         end = ((void *)drhd) + header->length;
 620
 621         while (start < end) {
 622                 scope = start;
 623                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_IOAPIC) {
 624                         if (ir_ioapic_num == MAX_IO_APICS) {
 625                                 printk(KERN_WARNING "Exceeded Max IO APICS\n");
 626                                 return -1;
 627                         }
 628
 629                         printk(KERN_INFO "IOAPIC id %d under DRHD base"
 630                                " 0x%Lx\n", scope->enumeration_id,
 631                                drhd->address);
 632
 633                         ir_ioapic[ir_ioapic_num].iommu = iommu;
 634                         ir_ioapic[ir_ioapic_num].id = scope->enumeration_id;
 635                         ir_ioapic_num++;
 636                 }
 637                 start += scope->length;
 638         }
 639
 640         return 0;
 641 }
 642
 643 /*
 644  * Finds the assocaition between IOAPIC's and its Interrupt-remapping
 645  * hardware unit.
 646  */
 647 int __init parse_ioapics_under_ir(void)
 648 {
 649         struct dmar_drhd_unit *drhd;
 650         int ir_supported = 0;
 651
 652         for_each_drhd_unit(drhd) {
 653                 struct intel_iommu *iommu = drhd->iommu;
 654
 655                 if (ecap_ir_support(iommu->ecap)) {
 656                         if (ir_parse_ioapic_scope(drhd->hdr, iommu))
 657                                 return -1;
 658
 659                         ir_supported = 1;
 660                 }
 661         }
 662
 663         if (ir_supported && ir_ioapic_num != nr_ioapics) {
 664                 printk(KERN_WARNING
 665                        "Not all IO-APIC's listed under remapping hardware\n");
 666                 return -1;
 667         }
 668
 669         return ir_supported;
 670 }
 671
 672 void disable_intr_remapping(void)
 673 {
 674         struct dmar_drhd_unit *drhd;
 675         struct intel_iommu *iommu = NULL;
 676
 677         /*
 678          * Disable Interrupt-remapping for all the DRHD's now.
 679          */
 680         for_each_iommu(iommu, drhd) {
 681                 if (!ecap_ir_support(iommu->ecap))
 682                         continue;
 683
 684                 iommu_disable_intr_remapping(iommu);
 685         }
 686 }
 687
 688 int reenable_intr_remapping(int eim)
 689 {
 690         struct dmar_drhd_unit *drhd;
 691         int setup = 0;
 692         struct intel_iommu *iommu = NULL;
 693
 694         for_each_iommu(iommu, drhd)
 695                 if (iommu->qi)
 696                         dmar_reenable_qi(iommu);
 697
 698         /*
 699          * Setup Interrupt-remapping for all the DRHD's now.
 700          */
 701         for_each_iommu(iommu, drhd) {
 702                 if (!ecap_ir_support(iommu->ecap))
 703                         continue;
 704
 705                 /* Set up interrupt remapping for iommu.*/
 706                 iommu_set_intr_remapping(iommu, eim);
 707                 setup = 1;
 708         }
 709
 710         if (!setup)
 711                 goto error;
 712
 713         return 0;
 714
 715 error:
 716         /*
 717          * handle error condition gracefully here!
 718          */
 719         return -1;
 720 }
 721