drivers/pci/intr_remapping.c

   1 #include <linux/dmar.h>
   2 #include <linux/spinlock.h>
   3 #include <linux/jiffies.h>
   4 #include <linux/pci.h>
   5 #include <linux/irq.h>
   6 #include <asm/io_apic.h>
   7 #include <linux/intel-iommu.h>
   8 #include "intr_remapping.h"
   9
  10 static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
  11 static int ir_ioapic_num;
  12 int intr_remapping_enabled;
  13
  14 static struct {
  15         struct intel_iommu *iommu;
  16         u16 irte_index;
  17         u16 sub_handle;
  18         u8  irte_mask;
  19 } irq_2_iommu[NR_IRQS];
  20
  21 static DEFINE_SPINLOCK(irq_2_ir_lock);
  22
  23 int irq_remapped(int irq)
  24 {
  25         if (irq > NR_IRQS)
  26                 return 0;
  27
  28         if (!irq_2_iommu[irq].iommu)
  29                 return 0;
  30
  31         return 1;
  32 }
  33
  34 int get_irte(int irq, struct irte *entry)
  35 {
  36         int index;
  37
  38         if (!entry || irq > NR_IRQS)
  39                 return -1;
  40
  41         spin_lock(&irq_2_ir_lock);
  42         if (!irq_2_iommu[irq].iommu) {
  43                 spin_unlock(&irq_2_ir_lock);
  44                 return -1;
  45         }
  46
  47         index = irq_2_iommu[irq].irte_index + irq_2_iommu[irq].sub_handle;
  48         *entry = *(irq_2_iommu[irq].iommu->ir_table->base + index);
  49
  50         spin_unlock(&irq_2_ir_lock);
  51         return 0;
  52 }
  53
  54 int alloc_irte(struct intel_iommu *iommu, int irq, u16 count)
  55 {
  56         struct ir_table *table = iommu->ir_table;
  57         u16 index, start_index;
  58         unsigned int mask = 0;
  59         int i;
  60
  61         if (!count)
  62                 return -1;
  63
  64         /*
  65          * start the IRTE search from index 0.
  66          */
  67         index = start_index = 0;
  68
  69         if (count > 1) {
  70                 count = __roundup_pow_of_two(count);
  71                 mask = ilog2(count);
  72         }
  73
  74         if (mask > ecap_max_handle_mask(iommu->ecap)) {
  75                 printk(KERN_ERR
  76                        "Requested mask %x exceeds the max invalidation handle"
  77                        " mask value %Lx\n", mask,
  78                        ecap_max_handle_mask(iommu->ecap));
  79                 return -1;
  80         }
  81
  82         spin_lock(&irq_2_ir_lock);
  83         do {
  84                 for (i = index; i < index + count; i++)
  85                         if  (table->base[i].present)
  86                                 break;
  87                 /* empty index found */
  88                 if (i == index + count)
  89                         break;
  90
  91                 index = (index + count) % INTR_REMAP_TABLE_ENTRIES;
  92
  93                 if (index == start_index) {
  94                         spin_unlock(&irq_2_ir_lock);
  95                         printk(KERN_ERR "can't allocate an IRTE\n");
  96                         return -1;
  97                 }
  98         } while (1);
  99
 100         for (i = index; i < index + count; i++)
 101                 table->base[i].present = 1;
 102
 103         irq_2_iommu[irq].iommu = iommu;
 104         irq_2_iommu[irq].irte_index =  index;
 105         irq_2_iommu[irq].sub_handle = 0;
 106         irq_2_iommu[irq].irte_mask = mask;
 107
 108         spin_unlock(&irq_2_ir_lock);
 109
 110         return index;
 111 }
 112
 113 static void qi_flush_iec(struct intel_iommu *iommu, int index, int mask)
 114 {
 115         struct qi_desc desc;
 116
 117         desc.low = QI_IEC_IIDEX(index) | QI_IEC_TYPE | QI_IEC_IM(mask)
 118                    | QI_IEC_SELECTIVE;
 119         desc.high = 0;
 120
 121         qi_submit_sync(&desc, iommu);
 122 }
 123
 124 int map_irq_to_irte_handle(int irq, u16 *sub_handle)
 125 {
 126         int index;
 127
 128         spin_lock(&irq_2_ir_lock);
 129         if (irq >= NR_IRQS || !irq_2_iommu[irq].iommu) {
 130                 spin_unlock(&irq_2_ir_lock);
 131                 return -1;
 132         }
 133
 134         *sub_handle = irq_2_iommu[irq].sub_handle;
 135         index = irq_2_iommu[irq].irte_index;
 136         spin_unlock(&irq_2_ir_lock);
 137         return index;
 138 }
 139
 140 int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subhandle)
 141 {
 142         spin_lock(&irq_2_ir_lock);
 143         if (irq >= NR_IRQS || irq_2_iommu[irq].iommu) {
 144                 spin_unlock(&irq_2_ir_lock);
 145                 return -1;
 146         }
 147
 148         irq_2_iommu[irq].iommu = iommu;
 149         irq_2_iommu[irq].irte_index = index;
 150         irq_2_iommu[irq].sub_handle = subhandle;
 151         irq_2_iommu[irq].irte_mask = 0;
 152
 153         spin_unlock(&irq_2_ir_lock);
 154
 155         return 0;
 156 }
 157
 158 int clear_irte_irq(int irq, struct intel_iommu *iommu, u16 index)
 159 {
 160         spin_lock(&irq_2_ir_lock);
 161         if (irq >= NR_IRQS || !irq_2_iommu[irq].iommu) {
 162                 spin_unlock(&irq_2_ir_lock);
 163                 return -1;
 164         }
 165
 166         irq_2_iommu[irq].iommu = NULL;
 167         irq_2_iommu[irq].irte_index = 0;
 168         irq_2_iommu[irq].sub_handle = 0;
 169         irq_2_iommu[irq].irte_mask = 0;
 170
 171         spin_unlock(&irq_2_ir_lock);
 172
 173         return 0;
 174 }
 175
 176 int modify_irte(int irq, struct irte *irte_modified)
 177 {
 178         int index;
 179         struct irte *irte;
 180         struct intel_iommu *iommu;
 181
 182         spin_lock(&irq_2_ir_lock);
 183         if (irq >= NR_IRQS || !irq_2_iommu[irq].iommu) {
 184                 spin_unlock(&irq_2_ir_lock);
 185                 return -1;
 186         }
 187
 188         iommu = irq_2_iommu[irq].iommu;
 189
 190         index = irq_2_iommu[irq].irte_index + irq_2_iommu[irq].sub_handle;
 191         irte = &iommu->ir_table->base[index];
 192
 193         set_64bit((unsigned long *)irte, irte_modified->low | (1 << 1));
 194         __iommu_flush_cache(iommu, irte, sizeof(*irte));
 195
 196         qi_flush_iec(iommu, index, 0);
 197
 198         spin_unlock(&irq_2_ir_lock);
 199         return 0;
 200 }
 201
 202 int flush_irte(int irq)
 203 {
 204         int index;
 205         struct intel_iommu *iommu;
 206
 207         spin_lock(&irq_2_ir_lock);
 208         if (irq >= NR_IRQS || !irq_2_iommu[irq].iommu) {
 209                 spin_unlock(&irq_2_ir_lock);
 210                 return -1;
 211         }
 212
 213         iommu = irq_2_iommu[irq].iommu;
 214
 215         index = irq_2_iommu[irq].irte_index + irq_2_iommu[irq].sub_handle;
 216
 217         qi_flush_iec(iommu, index, irq_2_iommu[irq].irte_mask);
 218         spin_unlock(&irq_2_ir_lock);
 219
 220         return 0;
 221 }
 222
 223 struct intel_iommu *map_ioapic_to_ir(int apic)
 224 {
 225         int i;
 226
 227         for (i = 0; i < MAX_IO_APICS; i++)
 228                 if (ir_ioapic[i].id == apic)
 229                         return ir_ioapic[i].iommu;
 230         return NULL;
 231 }
 232
 233 struct intel_iommu *map_dev_to_ir(struct pci_dev *dev)
 234 {
 235         struct dmar_drhd_unit *drhd;
 236
 237         drhd = dmar_find_matched_drhd_unit(dev);
 238         if (!drhd)
 239                 return NULL;
 240
 241         return drhd->iommu;
 242 }
 243
 244 int free_irte(int irq)
 245 {
 246         int index, i;
 247         struct irte *irte;
 248         struct intel_iommu *iommu;
 249
 250         spin_lock(&irq_2_ir_lock);
 251         if (irq >= NR_IRQS || !irq_2_iommu[irq].iommu) {
 252                 spin_unlock(&irq_2_ir_lock);
 253                 return -1;
 254         }
 255
 256         iommu = irq_2_iommu[irq].iommu;
 257
 258         index = irq_2_iommu[irq].irte_index + irq_2_iommu[irq].sub_handle;
 259         irte = &iommu->ir_table->base[index];
 260
 261         if (!irq_2_iommu[irq].sub_handle) {
 262                 for (i = 0; i < (1 << irq_2_iommu[irq].irte_mask); i++)
 263                         set_64bit((unsigned long *)irte, 0);
 264                 qi_flush_iec(iommu, index, irq_2_iommu[irq].irte_mask);
 265         }
 266
 267         irq_2_iommu[irq].iommu = NULL;
 268         irq_2_iommu[irq].irte_index = 0;
 269         irq_2_iommu[irq].sub_handle = 0;
 270         irq_2_iommu[irq].irte_mask = 0;
 271
 272         spin_unlock(&irq_2_ir_lock);
 273
 274         return 0;
 275 }
 276
 277 static void iommu_set_intr_remapping(struct intel_iommu *iommu, int mode)
 278 {
 279         u64 addr;
 280         u32 cmd, sts;
 281         unsigned long flags;
 282
 283         addr = virt_to_phys((void *)iommu->ir_table->base);
 284
 285         spin_lock_irqsave(&iommu->register_lock, flags);
 286
 287         dmar_writeq(iommu->reg + DMAR_IRTA_REG,
 288                     (addr) | IR_X2APIC_MODE(mode) | INTR_REMAP_TABLE_REG_SIZE);
 289
 290         /* Set interrupt-remapping table pointer */
 291         cmd = iommu->gcmd | DMA_GCMD_SIRTP;
 292         writel(cmd, iommu->reg + DMAR_GCMD_REG);
 293
 294         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 295                       readl, (sts & DMA_GSTS_IRTPS), sts);
 296         spin_unlock_irqrestore(&iommu->register_lock, flags);
 297
 298         /*
 299          * global invalidation of interrupt entry cache before enabling
 300          * interrupt-remapping.
 301          */
 302         qi_global_iec(iommu);
 303
 304         spin_lock_irqsave(&iommu->register_lock, flags);
 305
 306         /* Enable interrupt-remapping */
 307         cmd = iommu->gcmd | DMA_GCMD_IRE;
 308         iommu->gcmd |= DMA_GCMD_IRE;
 309         writel(cmd, iommu->reg + DMAR_GCMD_REG);
 310
 311         IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
 312                       readl, (sts & DMA_GSTS_IRES), sts);
 313
 314         spin_unlock_irqrestore(&iommu->register_lock, flags);
 315 }
 316
 317
 318 static int setup_intr_remapping(struct intel_iommu *iommu, int mode)
 319 {
 320         struct ir_table *ir_table;
 321         struct page *pages;
 322
 323         ir_table = iommu->ir_table = kzalloc(sizeof(struct ir_table),
 324                                              GFP_KERNEL);
 325
 326         if (!iommu->ir_table)
 327                 return -ENOMEM;
 328
 329         pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, INTR_REMAP_PAGE_ORDER);
 330
 331         if (!pages) {
 332                 printk(KERN_ERR "failed to allocate pages of order %d\n",
 333                        INTR_REMAP_PAGE_ORDER);
 334                 kfree(iommu->ir_table);
 335                 return -ENOMEM;
 336         }
 337
 338         ir_table->base = page_address(pages);
 339
 340         iommu_set_intr_remapping(iommu, mode);
 341         return 0;
 342 }
 343
 344 int __init enable_intr_remapping(int eim)
 345 {
 346         struct dmar_drhd_unit *drhd;
 347         int setup = 0;
 348
 349         /*
 350          * check for the Interrupt-remapping support
 351          */
 352         for_each_drhd_unit(drhd) {
 353                 struct intel_iommu *iommu = drhd->iommu;
 354
 355                 if (!ecap_ir_support(iommu->ecap))
 356                         continue;
 357
 358                 if (eim && !ecap_eim_support(iommu->ecap)) {
 359                         printk(KERN_INFO "DRHD %Lx: EIM not supported by DRHD, "
 360                                " ecap %Lx\n", drhd->reg_base_addr, iommu->ecap);
 361                         return -1;
 362                 }
 363         }
 364
 365         /*
 366          * Enable queued invalidation for all the DRHD's.
 367          */
 368         for_each_drhd_unit(drhd) {
 369                 int ret;
 370                 struct intel_iommu *iommu = drhd->iommu;
 371                 ret = dmar_enable_qi(iommu);
 372
 373                 if (ret) {
 374                         printk(KERN_ERR "DRHD %Lx: failed to enable queued, "
 375                                " invalidation, ecap %Lx, ret %d\n",
 376                                drhd->reg_base_addr, iommu->ecap, ret);
 377                         return -1;
 378                 }
 379         }
 380
 381         /*
 382          * Setup Interrupt-remapping for all the DRHD's now.
 383          */
 384         for_each_drhd_unit(drhd) {
 385                 struct intel_iommu *iommu = drhd->iommu;
 386
 387                 if (!ecap_ir_support(iommu->ecap))
 388                         continue;
 389
 390                 if (setup_intr_remapping(iommu, eim))
 391                         goto error;
 392
 393                 setup = 1;
 394         }
 395
 396         if (!setup)
 397                 goto error;
 398
 399         intr_remapping_enabled = 1;
 400
 401         return 0;
 402
 403 error:
 404         /*
 405          * handle error condition gracefully here!
 406          */
 407         return -1;
 408 }
 409
 410 static int ir_parse_ioapic_scope(struct acpi_dmar_header *header,
 411                                  struct intel_iommu *iommu)
 412 {
 413         struct acpi_dmar_hardware_unit *drhd;
 414         struct acpi_dmar_device_scope *scope;
 415         void *start, *end;
 416
 417         drhd = (struct acpi_dmar_hardware_unit *)header;
 418
 419         start = (void *)(drhd + 1);
 420         end = ((void *)drhd) + header->length;
 421
 422         while (start < end) {
 423                 scope = start;
 424                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_IOAPIC) {
 425                         if (ir_ioapic_num == MAX_IO_APICS) {
 426                                 printk(KERN_WARNING "Exceeded Max IO APICS\n");
 427                                 return -1;
 428                         }
 429
 430                         printk(KERN_INFO "IOAPIC id %d under DRHD base"
 431                                " 0x%Lx\n", scope->enumeration_id,
 432                                drhd->address);
 433
 434                         ir_ioapic[ir_ioapic_num].iommu = iommu;
 435                         ir_ioapic[ir_ioapic_num].id = scope->enumeration_id;
 436                         ir_ioapic_num++;
 437                 }
 438                 start += scope->length;
 439         }
 440
 441         return 0;
 442 }
 443
 444 /*
 445  * Finds the assocaition between IOAPIC's and its Interrupt-remapping
 446  * hardware unit.
 447  */
 448 int __init parse_ioapics_under_ir(void)
 449 {
 450         struct dmar_drhd_unit *drhd;
 451         int ir_supported = 0;
 452
 453         for_each_drhd_unit(drhd) {
 454                 struct intel_iommu *iommu = drhd->iommu;
 455
 456                 if (ecap_ir_support(iommu->ecap)) {
 457                         if (ir_parse_ioapic_scope(drhd->hdr, iommu))
 458                                 return -1;
 459
 460                         ir_supported = 1;
 461                 }
 462         }
 463
 464         if (ir_supported && ir_ioapic_num != nr_ioapics) {
 465                 printk(KERN_WARNING
 466                        "Not all IO-APIC's listed under remapping hardware\n");
 467                 return -1;
 468         }
 469
 470         return ir_supported;
 471 }