drivers/pci/controller/vmd.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Volume Management Device driver
   4  * Copyright (c) 2015, Intel Corporation.
   5  */
   6
   7 #include <linux/device.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/iommu.h>
  10 #include <linux/irq.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/msi.h>
  14 #include <linux/pci.h>
  15 #include <linux/pci-acpi.h>
  16 #include <linux/pci-ecam.h>
  17 #include <linux/srcu.h>
  18 #include <linux/rculist.h>
  19 #include <linux/rcupdate.h>
  20
  21 #include <asm/irqdomain.h>
  22
  23 #define VMD_CFGBAR      0
  24 #define VMD_MEMBAR1     2
  25 #define VMD_MEMBAR2     4
  26
  27 #define PCI_REG_VMCAP           0x40
  28 #define BUS_RESTRICT_CAP(vmcap) (vmcap & 0x1)
  29 #define PCI_REG_VMCONFIG        0x44
  30 #define BUS_RESTRICT_CFG(vmcfg) ((vmcfg >> 8) & 0x3)
  31 #define VMCONFIG_MSI_REMAP      0x2
  32 #define PCI_REG_VMLOCK          0x70
  33 #define MB2_SHADOW_EN(vmlock)   (vmlock & 0x2)
  34
  35 #define MB2_SHADOW_OFFSET       0x2000
  36 #define MB2_SHADOW_SIZE         16
  37
  38 enum vmd_features {
  39         /*
  40          * Device may contain registers which hint the physical location of the
  41          * membars, in order to allow proper address translation during
  42          * resource assignment to enable guest virtualization
  43          */
  44         VMD_FEAT_HAS_MEMBAR_SHADOW              = (1 << 0),
  45
  46         /*
  47          * Device may provide root port configuration information which limits
  48          * bus numbering
  49          */
  50         VMD_FEAT_HAS_BUS_RESTRICTIONS           = (1 << 1),
  51
  52         /*
  53          * Device contains physical location shadow registers in
  54          * vendor-specific capability space
  55          */
  56         VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP        = (1 << 2),
  57
  58         /*
  59          * Device may use MSI-X vector 0 for software triggering and will not
  60          * be used for MSI remapping
  61          */
  62         VMD_FEAT_OFFSET_FIRST_VECTOR            = (1 << 3),
  63
  64         /*
  65          * Device can bypass remapping MSI-X transactions into its MSI-X table,
  66          * avoiding the requirement of a VMD MSI domain for child device
  67          * interrupt handling.
  68          */
  69         VMD_FEAT_CAN_BYPASS_MSI_REMAP           = (1 << 4),
  70 };
  71
  72 static DEFINE_IDA(vmd_instance_ida);
  73
  74 /*
  75  * Lock for manipulating VMD IRQ lists.
  76  */
  77 static DEFINE_RAW_SPINLOCK(list_lock);
  78
  79 /**
  80  * struct vmd_irq - private data to map driver IRQ to the VMD shared vector
  81  * @node:       list item for parent traversal.
  82  * @irq:        back pointer to parent.
  83  * @enabled:    true if driver enabled IRQ
  84  * @virq:       the virtual IRQ value provided to the requesting driver.
  85  *
  86  * Every MSI/MSI-X IRQ requested for a device in a VMD domain will be mapped to
  87  * a VMD IRQ using this structure.
  88  */
  89 struct vmd_irq {
  90         struct list_head        node;
  91         struct vmd_irq_list     *irq;
  92         bool                    enabled;
  93         unsigned int            virq;
  94 };
  95
  96 /**
  97  * struct vmd_irq_list - list of driver requested IRQs mapping to a VMD vector
  98  * @irq_list:   the list of irq's the VMD one demuxes to.
  99  * @srcu:       SRCU struct for local synchronization.
 100  * @count:      number of child IRQs assigned to this vector; used to track
 101  *              sharing.
 102  */
 103 struct vmd_irq_list {
 104         struct list_head        irq_list;
 105         struct srcu_struct      srcu;
 106         unsigned int            count;
 107 };
 108
 109 struct vmd_dev {
 110         struct pci_dev          *dev;
 111
 112         spinlock_t              cfg_lock;
 113         void __iomem            *cfgbar;
 114
 115         int msix_count;
 116         struct vmd_irq_list     *irqs;
 117
 118         struct pci_sysdata      sysdata;
 119         struct resource         resources[3];
 120         struct irq_domain       *irq_domain;
 121         struct pci_bus          *bus;
 122         u8                      busn_start;
 123         u8                      first_vec;
 124         char                    *name;
 125         int                     instance;
 126 };
 127
 128 static inline struct vmd_dev *vmd_from_bus(struct pci_bus *bus)
 129 {
 130         return container_of(bus->sysdata, struct vmd_dev, sysdata);
 131 }
 132
 133 static inline unsigned int index_from_irqs(struct vmd_dev *vmd,
 134                                            struct vmd_irq_list *irqs)
 135 {
 136         return irqs - vmd->irqs;
 137 }
 138
 139 /*
 140  * Drivers managing a device in a VMD domain allocate their own IRQs as before,
 141  * but the MSI entry for the hardware it's driving will be programmed with a
 142  * destination ID for the VMD MSI-X table.  The VMD muxes interrupts in its
 143  * domain into one of its own, and the VMD driver de-muxes these for the
 144  * handlers sharing that VMD IRQ.  The vmd irq_domain provides the operations
 145  * and irq_chip to set this up.
 146  */
 147 static void vmd_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 148 {
 149         struct vmd_irq *vmdirq = data->chip_data;
 150         struct vmd_irq_list *irq = vmdirq->irq;
 151         struct vmd_dev *vmd = irq_data_get_irq_handler_data(data);
 152
 153         memset(msg, 0, sizeof(*msg));
 154         msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
 155         msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
 156         msg->arch_addr_lo.destid_0_7 = index_from_irqs(vmd, irq);
 157 }
 158
 159 /*
 160  * We rely on MSI_FLAG_USE_DEF_CHIP_OPS to set the IRQ mask/unmask ops.
 161  */
 162 static void vmd_irq_enable(struct irq_data *data)
 163 {
 164         struct vmd_irq *vmdirq = data->chip_data;
 165         unsigned long flags;
 166
 167         raw_spin_lock_irqsave(&list_lock, flags);
 168         WARN_ON(vmdirq->enabled);
 169         list_add_tail_rcu(&vmdirq->node, &vmdirq->irq->irq_list);
 170         vmdirq->enabled = true;
 171         raw_spin_unlock_irqrestore(&list_lock, flags);
 172
 173         data->chip->irq_unmask(data);
 174 }
 175
 176 static void vmd_irq_disable(struct irq_data *data)
 177 {
 178         struct vmd_irq *vmdirq = data->chip_data;
 179         unsigned long flags;
 180
 181         data->chip->irq_mask(data);
 182
 183         raw_spin_lock_irqsave(&list_lock, flags);
 184         if (vmdirq->enabled) {
 185                 list_del_rcu(&vmdirq->node);
 186                 vmdirq->enabled = false;
 187         }
 188         raw_spin_unlock_irqrestore(&list_lock, flags);
 189 }
 190
 191 /*
 192  * XXX: Stubbed until we develop acceptable way to not create conflicts with
 193  * other devices sharing the same vector.
 194  */
 195 static int vmd_irq_set_affinity(struct irq_data *data,
 196                                 const struct cpumask *dest, bool force)
 197 {
 198         return -EINVAL;
 199 }
 200
 201 static struct irq_chip vmd_msi_controller = {
 202         .name                   = "VMD-MSI",
 203         .irq_enable             = vmd_irq_enable,
 204         .irq_disable            = vmd_irq_disable,
 205         .irq_compose_msi_msg    = vmd_compose_msi_msg,
 206         .irq_set_affinity       = vmd_irq_set_affinity,
 207 };
 208
 209 static irq_hw_number_t vmd_get_hwirq(struct msi_domain_info *info,
 210                                      msi_alloc_info_t *arg)
 211 {
 212         return 0;
 213 }
 214
 215 /*
 216  * XXX: We can be even smarter selecting the best IRQ once we solve the
 217  * affinity problem.
 218  */
 219 static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd, struct msi_desc *desc)
 220 {
 221         unsigned long flags;
 222         int i, best;
 223
 224         if (vmd->msix_count == 1 + vmd->first_vec)
 225                 return &vmd->irqs[vmd->first_vec];
 226
 227         /*
 228          * White list for fast-interrupt handlers. All others will share the
 229          * "slow" interrupt vector.
 230          */
 231         switch (msi_desc_to_pci_dev(desc)->class) {
 232         case PCI_CLASS_STORAGE_EXPRESS:
 233                 break;
 234         default:
 235                 return &vmd->irqs[vmd->first_vec];
 236         }
 237
 238         raw_spin_lock_irqsave(&list_lock, flags);
 239         best = vmd->first_vec + 1;
 240         for (i = best; i < vmd->msix_count; i++)
 241                 if (vmd->irqs[i].count < vmd->irqs[best].count)
 242                         best = i;
 243         vmd->irqs[best].count++;
 244         raw_spin_unlock_irqrestore(&list_lock, flags);
 245
 246         return &vmd->irqs[best];
 247 }
 248
 249 static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info,
 250                         unsigned int virq, irq_hw_number_t hwirq,
 251                         msi_alloc_info_t *arg)
 252 {
 253         struct msi_desc *desc = arg->desc;
 254         struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(desc)->bus);
 255         struct vmd_irq *vmdirq = kzalloc(sizeof(*vmdirq), GFP_KERNEL);
 256         unsigned int index, vector;
 257
 258         if (!vmdirq)
 259                 return -ENOMEM;
 260
 261         INIT_LIST_HEAD(&vmdirq->node);
 262         vmdirq->irq = vmd_next_irq(vmd, desc);
 263         vmdirq->virq = virq;
 264         index = index_from_irqs(vmd, vmdirq->irq);
 265         vector = pci_irq_vector(vmd->dev, index);
 266
 267         irq_domain_set_info(domain, virq, vector, info->chip, vmdirq,
 268                             handle_untracked_irq, vmd, NULL);
 269         return 0;
 270 }
 271
 272 static void vmd_msi_free(struct irq_domain *domain,
 273                         struct msi_domain_info *info, unsigned int virq)
 274 {
 275         struct vmd_irq *vmdirq = irq_get_chip_data(virq);
 276         unsigned long flags;
 277
 278         synchronize_srcu(&vmdirq->irq->srcu);
 279
 280         /* XXX: Potential optimization to rebalance */
 281         raw_spin_lock_irqsave(&list_lock, flags);
 282         vmdirq->irq->count--;
 283         raw_spin_unlock_irqrestore(&list_lock, flags);
 284
 285         kfree(vmdirq);
 286 }
 287
 288 static int vmd_msi_prepare(struct irq_domain *domain, struct device *dev,
 289                            int nvec, msi_alloc_info_t *arg)
 290 {
 291         struct pci_dev *pdev = to_pci_dev(dev);
 292         struct vmd_dev *vmd = vmd_from_bus(pdev->bus);
 293
 294         if (nvec > vmd->msix_count)
 295                 return vmd->msix_count;
 296
 297         memset(arg, 0, sizeof(*arg));
 298         return 0;
 299 }
 300
 301 static void vmd_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
 302 {
 303         arg->desc = desc;
 304 }
 305
 306 static struct msi_domain_ops vmd_msi_domain_ops = {
 307         .get_hwirq      = vmd_get_hwirq,
 308         .msi_init       = vmd_msi_init,
 309         .msi_free       = vmd_msi_free,
 310         .msi_prepare    = vmd_msi_prepare,
 311         .set_desc       = vmd_set_desc,
 312 };
 313
 314 static struct msi_domain_info vmd_msi_domain_info = {
 315         .flags          = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
 316                           MSI_FLAG_PCI_MSIX,
 317         .ops            = &vmd_msi_domain_ops,
 318         .chip           = &vmd_msi_controller,
 319 };
 320
 321 static void vmd_set_msi_remapping(struct vmd_dev *vmd, bool enable)
 322 {
 323         u16 reg;
 324
 325         pci_read_config_word(vmd->dev, PCI_REG_VMCONFIG, &reg);
 326         reg = enable ? (reg & ~VMCONFIG_MSI_REMAP) :
 327                        (reg | VMCONFIG_MSI_REMAP);
 328         pci_write_config_word(vmd->dev, PCI_REG_VMCONFIG, reg);
 329 }
 330
 331 static int vmd_create_irq_domain(struct vmd_dev *vmd)
 332 {
 333         struct fwnode_handle *fn;
 334
 335         fn = irq_domain_alloc_named_id_fwnode("VMD-MSI", vmd->sysdata.domain);
 336         if (!fn)
 337                 return -ENODEV;
 338
 339         vmd->irq_domain = pci_msi_create_irq_domain(fn, &vmd_msi_domain_info, NULL);
 340         if (!vmd->irq_domain) {
 341                 irq_domain_free_fwnode(fn);
 342                 return -ENODEV;
 343         }
 344
 345         return 0;
 346 }
 347
 348 static void vmd_remove_irq_domain(struct vmd_dev *vmd)
 349 {
 350         /*
 351          * Some production BIOS won't enable remapping between soft reboots.
 352          * Ensure remapping is restored before unloading the driver.
 353          */
 354         if (!vmd->msix_count)
 355                 vmd_set_msi_remapping(vmd, true);
 356
 357         if (vmd->irq_domain) {
 358                 struct fwnode_handle *fn = vmd->irq_domain->fwnode;
 359
 360                 irq_domain_remove(vmd->irq_domain);
 361                 irq_domain_free_fwnode(fn);
 362         }
 363 }
 364
 365 static void __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
 366                                   unsigned int devfn, int reg, int len)
 367 {
 368         unsigned int busnr_ecam = bus->number - vmd->busn_start;
 369         u32 offset = PCIE_ECAM_OFFSET(busnr_ecam, devfn, reg);
 370
 371         if (offset + len >= resource_size(&vmd->dev->resource[VMD_CFGBAR]))
 372                 return NULL;
 373
 374         return vmd->cfgbar + offset;
 375 }
 376
 377 /*
 378  * CPU may deadlock if config space is not serialized on some versions of this
 379  * hardware, so all config space access is done under a spinlock.
 380  */
 381 static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
 382                         int len, u32 *value)
 383 {
 384         struct vmd_dev *vmd = vmd_from_bus(bus);
 385         void __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
 386         unsigned long flags;
 387         int ret = 0;
 388
 389         if (!addr)
 390                 return -EFAULT;
 391
 392         spin_lock_irqsave(&vmd->cfg_lock, flags);
 393         switch (len) {
 394         case 1:
 395                 *value = readb(addr);
 396                 break;
 397         case 2:
 398                 *value = readw(addr);
 399                 break;
 400         case 4:
 401                 *value = readl(addr);
 402                 break;
 403         default:
 404                 ret = -EINVAL;
 405                 break;
 406         }
 407         spin_unlock_irqrestore(&vmd->cfg_lock, flags);
 408         return ret;
 409 }
 410
 411 /*
 412  * VMD h/w converts non-posted config writes to posted memory writes. The
 413  * read-back in this function forces the completion so it returns only after
 414  * the config space was written, as expected.
 415  */
 416 static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg,
 417                          int len, u32 value)
 418 {
 419         struct vmd_dev *vmd = vmd_from_bus(bus);
 420         void __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
 421         unsigned long flags;
 422         int ret = 0;
 423
 424         if (!addr)
 425                 return -EFAULT;
 426
 427         spin_lock_irqsave(&vmd->cfg_lock, flags);
 428         switch (len) {
 429         case 1:
 430                 writeb(value, addr);
 431                 readb(addr);
 432                 break;
 433         case 2:
 434                 writew(value, addr);
 435                 readw(addr);
 436                 break;
 437         case 4:
 438                 writel(value, addr);
 439                 readl(addr);
 440                 break;
 441         default:
 442                 ret = -EINVAL;
 443                 break;
 444         }
 445         spin_unlock_irqrestore(&vmd->cfg_lock, flags);
 446         return ret;
 447 }
 448
 449 static struct pci_ops vmd_ops = {
 450         .read           = vmd_pci_read,
 451         .write          = vmd_pci_write,
 452 };
 453
 454 #ifdef CONFIG_ACPI
 455 static struct acpi_device *vmd_acpi_find_companion(struct pci_dev *pci_dev)
 456 {
 457         struct pci_host_bridge *bridge;
 458         u32 busnr, addr;
 459
 460         if (pci_dev->bus->ops != &vmd_ops)
 461                 return NULL;
 462
 463         bridge = pci_find_host_bridge(pci_dev->bus);
 464         busnr = pci_dev->bus->number - bridge->bus->number;
 465         /*
 466          * The address computation below is only applicable to relative bus
 467          * numbers below 32.
 468          */
 469         if (busnr > 31)
 470                 return NULL;
 471
 472         addr = (busnr << 24) | ((u32)pci_dev->devfn << 16) | 0x8000FFFFU;
 473
 474         dev_dbg(&pci_dev->dev, "Looking for ACPI companion (address 0x%x)\n",
 475                 addr);
 476
 477         return acpi_find_child_device(ACPI_COMPANION(bridge->dev.parent), addr,
 478                                       false);
 479 }
 480
 481 static bool hook_installed;
 482
 483 static void vmd_acpi_begin(void)
 484 {
 485         if (pci_acpi_set_companion_lookup_hook(vmd_acpi_find_companion))
 486                 return;
 487
 488         hook_installed = true;
 489 }
 490
 491 static void vmd_acpi_end(void)
 492 {
 493         if (!hook_installed)
 494                 return;
 495
 496         pci_acpi_clear_companion_lookup_hook();
 497         hook_installed = false;
 498 }
 499 #else
 500 static inline void vmd_acpi_begin(void) { }
 501 static inline void vmd_acpi_end(void) { }
 502 #endif /* CONFIG_ACPI */
 503
 504 static void vmd_domain_reset(struct vmd_dev *vmd)
 505 {
 506         u16 bus, max_buses = resource_size(&vmd->resources[0]);
 507         u8 dev, functions, fn, hdr_type;
 508         char __iomem *base;
 509
 510         for (bus = 0; bus < max_buses; bus++) {
 511                 for (dev = 0; dev < 32; dev++) {
 512                         base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
 513                                                 PCI_DEVFN(dev, 0), 0);
 514
 515                         hdr_type = readb(base + PCI_HEADER_TYPE) &
 516                                          PCI_HEADER_TYPE_MASK;
 517
 518                         functions = (hdr_type & 0x80) ? 8 : 1;
 519                         for (fn = 0; fn < functions; fn++) {
 520                                 base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
 521                                                 PCI_DEVFN(dev, fn), 0);
 522
 523                                 hdr_type = readb(base + PCI_HEADER_TYPE) &
 524                                                 PCI_HEADER_TYPE_MASK;
 525
 526                                 if (hdr_type != PCI_HEADER_TYPE_BRIDGE ||
 527                                     (readw(base + PCI_CLASS_DEVICE) !=
 528                                      PCI_CLASS_BRIDGE_PCI))
 529                                         continue;
 530
 531                                 memset_io(base + PCI_IO_BASE, 0,
 532                                           PCI_ROM_ADDRESS1 - PCI_IO_BASE);
 533                         }
 534                 }
 535         }
 536 }
 537
 538 static void vmd_attach_resources(struct vmd_dev *vmd)
 539 {
 540         vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[1];
 541         vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[2];
 542 }
 543
 544 static void vmd_detach_resources(struct vmd_dev *vmd)
 545 {
 546         vmd->dev->resource[VMD_MEMBAR1].child = NULL;
 547         vmd->dev->resource[VMD_MEMBAR2].child = NULL;
 548 }
 549
 550 /*
 551  * VMD domains start at 0x10000 to not clash with ACPI _SEG domains.
 552  * Per ACPI r6.0, sec 6.5.6,  _SEG returns an integer, of which the lower
 553  * 16 bits are the PCI Segment Group (domain) number.  Other bits are
 554  * currently reserved.
 555  */
 556 static int vmd_find_free_domain(void)
 557 {
 558         int domain = 0xffff;
 559         struct pci_bus *bus = NULL;
 560
 561         while ((bus = pci_find_next_bus(bus)) != NULL)
 562                 domain = max_t(int, domain, pci_domain_nr(bus));
 563         return domain + 1;
 564 }
 565
 566 static int vmd_get_phys_offsets(struct vmd_dev *vmd, bool native_hint,
 567                                 resource_size_t *offset1,
 568                                 resource_size_t *offset2)
 569 {
 570         struct pci_dev *dev = vmd->dev;
 571         u64 phys1, phys2;
 572
 573         if (native_hint) {
 574                 u32 vmlock;
 575                 int ret;
 576
 577                 ret = pci_read_config_dword(dev, PCI_REG_VMLOCK, &vmlock);
 578                 if (ret || PCI_POSSIBLE_ERROR(vmlock))
 579                         return -ENODEV;
 580
 581                 if (MB2_SHADOW_EN(vmlock)) {
 582                         void __iomem *membar2;
 583
 584                         membar2 = pci_iomap(dev, VMD_MEMBAR2, 0);
 585                         if (!membar2)
 586                                 return -ENOMEM;
 587                         phys1 = readq(membar2 + MB2_SHADOW_OFFSET);
 588                         phys2 = readq(membar2 + MB2_SHADOW_OFFSET + 8);
 589                         pci_iounmap(dev, membar2);
 590                 } else
 591                         return 0;
 592         } else {
 593                 /* Hypervisor-Emulated Vendor-Specific Capability */
 594                 int pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
 595                 u32 reg, regu;
 596
 597                 pci_read_config_dword(dev, pos + 4, &reg);
 598
 599                 /* "SHDW" */
 600                 if (pos && reg == 0x53484457) {
 601                         pci_read_config_dword(dev, pos + 8, &reg);
 602                         pci_read_config_dword(dev, pos + 12, &regu);
 603                         phys1 = (u64) regu << 32 | reg;
 604
 605                         pci_read_config_dword(dev, pos + 16, &reg);
 606                         pci_read_config_dword(dev, pos + 20, &regu);
 607                         phys2 = (u64) regu << 32 | reg;
 608                 } else
 609                         return 0;
 610         }
 611
 612         *offset1 = dev->resource[VMD_MEMBAR1].start -
 613                         (phys1 & PCI_BASE_ADDRESS_MEM_MASK);
 614         *offset2 = dev->resource[VMD_MEMBAR2].start -
 615                         (phys2 & PCI_BASE_ADDRESS_MEM_MASK);
 616
 617         return 0;
 618 }
 619
 620 static int vmd_get_bus_number_start(struct vmd_dev *vmd)
 621 {
 622         struct pci_dev *dev = vmd->dev;
 623         u16 reg;
 624
 625         pci_read_config_word(dev, PCI_REG_VMCAP, &reg);
 626         if (BUS_RESTRICT_CAP(reg)) {
 627                 pci_read_config_word(dev, PCI_REG_VMCONFIG, &reg);
 628
 629                 switch (BUS_RESTRICT_CFG(reg)) {
 630                 case 0:
 631                         vmd->busn_start = 0;
 632                         break;
 633                 case 1:
 634                         vmd->busn_start = 128;
 635                         break;
 636                 case 2:
 637                         vmd->busn_start = 224;
 638                         break;
 639                 default:
 640                         pci_err(dev, "Unknown Bus Offset Setting (%d)\n",
 641                                 BUS_RESTRICT_CFG(reg));
 642                         return -ENODEV;
 643                 }
 644         }
 645
 646         return 0;
 647 }
 648
 649 static irqreturn_t vmd_irq(int irq, void *data)
 650 {
 651         struct vmd_irq_list *irqs = data;
 652         struct vmd_irq *vmdirq;
 653         int idx;
 654
 655         idx = srcu_read_lock(&irqs->srcu);
 656         list_for_each_entry_rcu(vmdirq, &irqs->irq_list, node)
 657                 generic_handle_irq(vmdirq->virq);
 658         srcu_read_unlock(&irqs->srcu, idx);
 659
 660         return IRQ_HANDLED;
 661 }
 662
 663 static int vmd_alloc_irqs(struct vmd_dev *vmd)
 664 {
 665         struct pci_dev *dev = vmd->dev;
 666         int i, err;
 667
 668         vmd->msix_count = pci_msix_vec_count(dev);
 669         if (vmd->msix_count < 0)
 670                 return -ENODEV;
 671
 672         vmd->msix_count = pci_alloc_irq_vectors(dev, vmd->first_vec + 1,
 673                                                 vmd->msix_count, PCI_IRQ_MSIX);
 674         if (vmd->msix_count < 0)
 675                 return vmd->msix_count;
 676
 677         vmd->irqs = devm_kcalloc(&dev->dev, vmd->msix_count, sizeof(*vmd->irqs),
 678                                  GFP_KERNEL);
 679         if (!vmd->irqs)
 680                 return -ENOMEM;
 681
 682         for (i = 0; i < vmd->msix_count; i++) {
 683                 err = init_srcu_struct(&vmd->irqs[i].srcu);
 684                 if (err)
 685                         return err;
 686
 687                 INIT_LIST_HEAD(&vmd->irqs[i].irq_list);
 688                 err = devm_request_irq(&dev->dev, pci_irq_vector(dev, i),
 689                                        vmd_irq, IRQF_NO_THREAD,
 690                                        vmd->name, &vmd->irqs[i]);
 691                 if (err)
 692                         return err;
 693         }
 694
 695         return 0;
 696 }
 697
 698 /*
 699  * Since VMD is an aperture to regular PCIe root ports, only allow it to
 700  * control features that the OS is allowed to control on the physical PCI bus.
 701  */
 702 static void vmd_copy_host_bridge_flags(struct pci_host_bridge *root_bridge,
 703                                        struct pci_host_bridge *vmd_bridge)
 704 {
 705         vmd_bridge->native_pcie_hotplug = root_bridge->native_pcie_hotplug;
 706         vmd_bridge->native_shpc_hotplug = root_bridge->native_shpc_hotplug;
 707         vmd_bridge->native_aer = root_bridge->native_aer;
 708         vmd_bridge->native_pme = root_bridge->native_pme;
 709         vmd_bridge->native_ltr = root_bridge->native_ltr;
 710         vmd_bridge->native_dpc = root_bridge->native_dpc;
 711 }
 712
 713 static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 714 {
 715         struct pci_sysdata *sd = &vmd->sysdata;
 716         struct resource *res;
 717         u32 upper_bits;
 718         unsigned long flags;
 719         LIST_HEAD(resources);
 720         resource_size_t offset[2] = {0};
 721         resource_size_t membar2_offset = 0x2000;
 722         struct pci_bus *child;
 723         int ret;
 724
 725         /*
 726          * Shadow registers may exist in certain VMD device ids which allow
 727          * guests to correctly assign host physical addresses to the root ports
 728          * and child devices. These registers will either return the host value
 729          * or 0, depending on an enable bit in the VMD device.
 730          */
 731         if (features & VMD_FEAT_HAS_MEMBAR_SHADOW) {
 732                 membar2_offset = MB2_SHADOW_OFFSET + MB2_SHADOW_SIZE;
 733                 ret = vmd_get_phys_offsets(vmd, true, &offset[0], &offset[1]);
 734                 if (ret)
 735                         return ret;
 736         } else if (features & VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP) {
 737                 ret = vmd_get_phys_offsets(vmd, false, &offset[0], &offset[1]);
 738                 if (ret)
 739                         return ret;
 740         }
 741
 742         /*
 743          * Certain VMD devices may have a root port configuration option which
 744          * limits the bus range to between 0-127, 128-255, or 224-255
 745          */
 746         if (features & VMD_FEAT_HAS_BUS_RESTRICTIONS) {
 747                 ret = vmd_get_bus_number_start(vmd);
 748                 if (ret)
 749                         return ret;
 750         }
 751
 752         res = &vmd->dev->resource[VMD_CFGBAR];
 753         vmd->resources[0] = (struct resource) {
 754                 .name  = "VMD CFGBAR",
 755                 .start = vmd->busn_start,
 756                 .end   = vmd->busn_start + (resource_size(res) >> 20) - 1,
 757                 .flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
 758         };
 759
 760         /*
 761          * If the window is below 4GB, clear IORESOURCE_MEM_64 so we can
 762          * put 32-bit resources in the window.
 763          *
 764          * There's no hardware reason why a 64-bit window *couldn't*
 765          * contain a 32-bit resource, but pbus_size_mem() computes the
 766          * bridge window size assuming a 64-bit window will contain no
 767          * 32-bit resources.  __pci_assign_resource() enforces that
 768          * artificial restriction to make sure everything will fit.
 769          *
 770          * The only way we could use a 64-bit non-prefetchable MEMBAR is
 771          * if its address is <4GB so that we can convert it to a 32-bit
 772          * resource.  To be visible to the host OS, all VMD endpoints must
 773          * be initially configured by platform BIOS, which includes setting
 774          * up these resources.  We can assume the device is configured
 775          * according to the platform needs.
 776          */
 777         res = &vmd->dev->resource[VMD_MEMBAR1];
 778         upper_bits = upper_32_bits(res->end);
 779         flags = res->flags & ~IORESOURCE_SIZEALIGN;
 780         if (!upper_bits)
 781                 flags &= ~IORESOURCE_MEM_64;
 782         vmd->resources[1] = (struct resource) {
 783                 .name  = "VMD MEMBAR1",
 784                 .start = res->start,
 785                 .end   = res->end,
 786                 .flags = flags,
 787                 .parent = res,
 788         };
 789
 790         res = &vmd->dev->resource[VMD_MEMBAR2];
 791         upper_bits = upper_32_bits(res->end);
 792         flags = res->flags & ~IORESOURCE_SIZEALIGN;
 793         if (!upper_bits)
 794                 flags &= ~IORESOURCE_MEM_64;
 795         vmd->resources[2] = (struct resource) {
 796                 .name  = "VMD MEMBAR2",
 797                 .start = res->start + membar2_offset,
 798                 .end   = res->end,
 799                 .flags = flags,
 800                 .parent = res,
 801         };
 802
 803         sd->vmd_dev = vmd->dev;
 804         sd->domain = vmd_find_free_domain();
 805         if (sd->domain < 0)
 806                 return sd->domain;
 807
 808         sd->node = pcibus_to_node(vmd->dev->bus);
 809
 810         /*
 811          * Currently MSI remapping must be enabled in guest passthrough mode
 812          * due to some missing interrupt remapping plumbing. This is probably
 813          * acceptable because the guest is usually CPU-limited and MSI
 814          * remapping doesn't become a performance bottleneck.
 815          */
 816         if (iommu_capable(vmd->dev->dev.bus, IOMMU_CAP_INTR_REMAP) ||
 817             !(features & VMD_FEAT_CAN_BYPASS_MSI_REMAP) ||
 818             offset[0] || offset[1]) {
 819                 ret = vmd_alloc_irqs(vmd);
 820                 if (ret)
 821                         return ret;
 822
 823                 vmd_set_msi_remapping(vmd, true);
 824
 825                 ret = vmd_create_irq_domain(vmd);
 826                 if (ret)
 827                         return ret;
 828
 829                 /*
 830                  * Override the IRQ domain bus token so the domain can be
 831                  * distinguished from a regular PCI/MSI domain.
 832                  */
 833                 irq_domain_update_bus_token(vmd->irq_domain, DOMAIN_BUS_VMD_MSI);
 834         } else {
 835                 vmd_set_msi_remapping(vmd, false);
 836         }
 837
 838         pci_add_resource(&resources, &vmd->resources[0]);
 839         pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
 840         pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
 841
 842         vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
 843                                        &vmd_ops, sd, &resources);
 844         if (!vmd->bus) {
 845                 pci_free_resource_list(&resources);
 846                 vmd_remove_irq_domain(vmd);
 847                 return -ENODEV;
 848         }
 849
 850         vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
 851                                    to_pci_host_bridge(vmd->bus->bridge));
 852
 853         vmd_attach_resources(vmd);
 854         if (vmd->irq_domain)
 855                 dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
 856
 857         vmd_acpi_begin();
 858
 859         pci_scan_child_bus(vmd->bus);
 860         vmd_domain_reset(vmd);
 861         list_for_each_entry(child, &vmd->bus->children, node)
 862                 pci_reset_bus(child->self);
 863         pci_assign_unassigned_bus_resources(vmd->bus);
 864
 865         /*
 866          * VMD root buses are virtual and don't return true on pci_is_pcie()
 867          * and will fail pcie_bus_configure_settings() early. It can instead be
 868          * run on each of the real root ports.
 869          */
 870         list_for_each_entry(child, &vmd->bus->children, node)
 871                 pcie_bus_configure_settings(child);
 872
 873         pci_bus_add_devices(vmd->bus);
 874
 875         vmd_acpi_end();
 876
 877         WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
 878                                "domain"), "Can't create symlink to domain\n");
 879         return 0;
 880 }
 881
 882 static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 883 {
 884         unsigned long features = (unsigned long) id->driver_data;
 885         struct vmd_dev *vmd;
 886         int err;
 887
 888         if (resource_size(&dev->resource[VMD_CFGBAR]) < (1 << 20))
 889                 return -ENOMEM;
 890
 891         vmd = devm_kzalloc(&dev->dev, sizeof(*vmd), GFP_KERNEL);
 892         if (!vmd)
 893                 return -ENOMEM;
 894
 895         vmd->dev = dev;
 896         vmd->instance = ida_simple_get(&vmd_instance_ida, 0, 0, GFP_KERNEL);
 897         if (vmd->instance < 0)
 898                 return vmd->instance;
 899
 900         vmd->name = kasprintf(GFP_KERNEL, "vmd%d", vmd->instance);
 901         if (!vmd->name) {
 902                 err = -ENOMEM;
 903                 goto out_release_instance;
 904         }
 905
 906         err = pcim_enable_device(dev);
 907         if (err < 0)
 908                 goto out_release_instance;
 909
 910         vmd->cfgbar = pcim_iomap(dev, VMD_CFGBAR, 0);
 911         if (!vmd->cfgbar) {
 912                 err = -ENOMEM;
 913                 goto out_release_instance;
 914         }
 915
 916         pci_set_master(dev);
 917         if (dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(64)) &&
 918             dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32))) {
 919                 err = -ENODEV;
 920                 goto out_release_instance;
 921         }
 922
 923         if (features & VMD_FEAT_OFFSET_FIRST_VECTOR)
 924                 vmd->first_vec = 1;
 925
 926         spin_lock_init(&vmd->cfg_lock);
 927         pci_set_drvdata(dev, vmd);
 928         err = vmd_enable_domain(vmd, features);
 929         if (err)
 930                 goto out_release_instance;
 931
 932         dev_info(&vmd->dev->dev, "Bound to PCI domain %04x\n",
 933                  vmd->sysdata.domain);
 934         return 0;
 935
 936  out_release_instance:
 937         ida_simple_remove(&vmd_instance_ida, vmd->instance);
 938         kfree(vmd->name);
 939         return err;
 940 }
 941
 942 static void vmd_cleanup_srcu(struct vmd_dev *vmd)
 943 {
 944         int i;
 945
 946         for (i = 0; i < vmd->msix_count; i++)
 947                 cleanup_srcu_struct(&vmd->irqs[i].srcu);
 948 }
 949
 950 static void vmd_remove(struct pci_dev *dev)
 951 {
 952         struct vmd_dev *vmd = pci_get_drvdata(dev);
 953
 954         sysfs_remove_link(&vmd->dev->dev.kobj, "domain");
 955         pci_stop_root_bus(vmd->bus);
 956         pci_remove_root_bus(vmd->bus);
 957         vmd_cleanup_srcu(vmd);
 958         vmd_detach_resources(vmd);
 959         vmd_remove_irq_domain(vmd);
 960         ida_simple_remove(&vmd_instance_ida, vmd->instance);
 961         kfree(vmd->name);
 962 }
 963
 964 #ifdef CONFIG_PM_SLEEP
 965 static int vmd_suspend(struct device *dev)
 966 {
 967         struct pci_dev *pdev = to_pci_dev(dev);
 968         struct vmd_dev *vmd = pci_get_drvdata(pdev);
 969         int i;
 970
 971         for (i = 0; i < vmd->msix_count; i++)
 972                 devm_free_irq(dev, pci_irq_vector(pdev, i), &vmd->irqs[i]);
 973
 974         return 0;
 975 }
 976
 977 static int vmd_resume(struct device *dev)
 978 {
 979         struct pci_dev *pdev = to_pci_dev(dev);
 980         struct vmd_dev *vmd = pci_get_drvdata(pdev);
 981         int err, i;
 982
 983         for (i = 0; i < vmd->msix_count; i++) {
 984                 err = devm_request_irq(dev, pci_irq_vector(pdev, i),
 985                                        vmd_irq, IRQF_NO_THREAD,
 986                                        vmd->name, &vmd->irqs[i]);
 987                 if (err)
 988                         return err;
 989         }
 990
 991         return 0;
 992 }
 993 #endif
 994 static SIMPLE_DEV_PM_OPS(vmd_dev_pm_ops, vmd_suspend, vmd_resume);
 995
 996 static const struct pci_device_id vmd_ids[] = {
 997         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_VMD_201D),
 998                 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP,},
 999         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_VMD_28C0),
1000                 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW |
1001                                 VMD_FEAT_HAS_BUS_RESTRICTIONS |
1002                                 VMD_FEAT_CAN_BYPASS_MSI_REMAP,},
1003         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x467f),
1004                 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
1005                                 VMD_FEAT_HAS_BUS_RESTRICTIONS |
1006                                 VMD_FEAT_OFFSET_FIRST_VECTOR,},
1007         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x4c3d),
1008                 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
1009                                 VMD_FEAT_HAS_BUS_RESTRICTIONS |
1010                                 VMD_FEAT_OFFSET_FIRST_VECTOR,},
1011         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0xa77f),
1012                 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
1013                                 VMD_FEAT_HAS_BUS_RESTRICTIONS |
1014                                 VMD_FEAT_OFFSET_FIRST_VECTOR,},
1015         {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B),
1016                 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
1017                                 VMD_FEAT_HAS_BUS_RESTRICTIONS |
1018                                 VMD_FEAT_OFFSET_FIRST_VECTOR,},
1019         {0,}
1020 };
1021 MODULE_DEVICE_TABLE(pci, vmd_ids);
1022
1023 static struct pci_driver vmd_drv = {
1024         .name           = "vmd",
1025         .id_table       = vmd_ids,
1026         .probe          = vmd_probe,
1027         .remove         = vmd_remove,
1028         .driver         = {
1029                 .pm     = &vmd_dev_pm_ops,
1030         },
1031 };
1032 module_pci_driver(vmd_drv);
1033
1034 MODULE_AUTHOR("Intel Corporation");
1035 MODULE_LICENSE("GPL v2");
1036 MODULE_VERSION("0.6");