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