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/irq.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/msi.h>
  13 #include <linux/pci.h>
  14 #include <linux/pci-acpi.h>
  15 #include <linux/pci-ecam.h>
  16 #include <linux/srcu.h>
  17 #include <linux/rculist.h>
  18 #include <linux/rcupdate.h>
  19
  20 #include <asm/irqdomain.h>
  21
  22 #define VMD_CFGBAR      0
  23 #define VMD_MEMBAR1     2
  24 #define VMD_MEMBAR2     4
  25
  26 #define PCI_REG_VMCAP           0x40
  27 #define BUS_RESTRICT_CAP(vmcap) (vmcap & 0x1)
  28 #define PCI_REG_VMCONFIG        0x44
  29 #define BUS_RESTRICT_CFG(vmcfg) ((vmcfg >> 8) & 0x3)
  30 #define VMCONFIG_MSI_REMAP      0x2
  31 #define PCI_REG_VMLOCK          0x70
  32 #define MB2_SHADOW_EN(vmlock)   (vmlock & 0x2)
  33
  34 #define MB2_SHADOW_OFFSET       0x2000
  35 #define MB2_SHADOW_SIZE         16
  36
  37 enum vmd_features {
  38         /*
  39          * Device may contain registers which hint the physical location of the
  40          * membars, in order to allow proper address translation during
  41          * resource assignment to enable guest virtualization
  42          */
  43         VMD_FEAT_HAS_MEMBAR_SHADOW              = (1 << 0),
  44
  45         /*
  46          * Device may provide root port configuration information which limits
  47          * bus numbering
  48          */
  49         VMD_FEAT_HAS_BUS_RESTRICTIONS           = (1 << 1),
  50
  51         /*
  52          * Device contains physical location shadow registers in
  53          * vendor-specific capability space
  54          */
  55         VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP        = (1 << 2),
  56
  57         /*
  58          * Device may use MSI-X vector 0 for software triggering and will not
  59          * be used for MSI remapping
  60          */
  61         VMD_FEAT_OFFSET_FIRST_VECTOR            = (1 << 3),
  62
  63         /*
  64          * Device can bypass remapping MSI-X transactions into its MSI-X table,
  65          * avoiding the requirement of a VMD MSI domain for child device
  66          * interrupt handling.
  67          */
  68         VMD_FEAT_CAN_BYPASS_MSI_REMAP           = (1 << 4),
  69
  70         /*
  71          * Enable ASPM on the PCIE root ports and set the default LTR of the
  72          * storage devices on platforms where these values are not configured by
  73          * BIOS. This is needed for laptops, which require these settings for
  74          * proper power management of the SoC.
  75          */
  76         VMD_FEAT_BIOS_PM_QUIRK          = (1 << 5),
  77 };
  78
  79 #define VMD_BIOS_PM_QUIRK_LTR   0x1003  /* 3145728 ns */
  80
  81 #define VMD_FEATS_CLIENT        (VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |     \
  82                                  VMD_FEAT_HAS_BUS_RESTRICTIONS |        \
  83                                  VMD_FEAT_OFFSET_FIRST_VECTOR |         \
  84                                  VMD_FEAT_BIOS_PM_QUIRK)
  85
  86 static DEFINE_IDA(vmd_instance_ida);
  87
  88 /*
  89  * Lock for manipulating VMD IRQ lists.
  90  */
  91 static DEFINE_RAW_SPINLOCK(list_lock);
  92
  93 /**
  94  * struct vmd_irq - private data to map driver IRQ to the VMD shared vector
  95  * @node:       list item for parent traversal.
  96  * @irq:        back pointer to parent.
  97  * @enabled:    true if driver enabled IRQ
  98  * @virq:       the virtual IRQ value provided to the requesting driver.
  99  *
 100  * Every MSI/MSI-X IRQ requested for a device in a VMD domain will be mapped to
 101  * a VMD IRQ using this structure.
 102  */
 103 struct vmd_irq {
 104         struct list_head        node;
 105         struct vmd_irq_list     *irq;
 106         bool                    enabled;
 107         unsigned int            virq;
 108 };
 109
 110 /**
 111  * struct vmd_irq_list - list of driver requested IRQs mapping to a VMD vector
 112  * @irq_list:   the list of irq's the VMD one demuxes to.
 113  * @srcu:       SRCU struct for local synchronization.
 114  * @count:      number of child IRQs assigned to this vector; used to track
 115  *              sharing.
 116  * @virq:       The underlying VMD Linux interrupt number
 117  */
 118 struct vmd_irq_list {
 119         struct list_head        irq_list;
 120         struct srcu_struct      srcu;
 121         unsigned int            count;
 122         unsigned int            virq;
 123 };
 124
 125 struct vmd_dev {
 126         struct pci_dev          *dev;
 127
 128         spinlock_t              cfg_lock;
 129         void __iomem            *cfgbar;
 130
 131         int msix_count;
 132         struct vmd_irq_list     *irqs;
 133
 134         struct pci_sysdata      sysdata;
 135         struct resource         resources[3];
 136         struct irq_domain       *irq_domain;
 137         struct pci_bus          *bus;
 138         u8                      busn_start;
 139         u8                      first_vec;
 140         char                    *name;
 141         int                     instance;
 142 };
 143
 144 static inline struct vmd_dev *vmd_from_bus(struct pci_bus *bus)
 145 {
 146         return container_of(bus->sysdata, struct vmd_dev, sysdata);
 147 }
 148
 149 static inline unsigned int index_from_irqs(struct vmd_dev *vmd,
 150                                            struct vmd_irq_list *irqs)
 151 {
 152         return irqs - vmd->irqs;
 153 }
 154
 155 /*
 156  * Drivers managing a device in a VMD domain allocate their own IRQs as before,
 157  * but the MSI entry for the hardware it's driving will be programmed with a
 158  * destination ID for the VMD MSI-X table.  The VMD muxes interrupts in its
 159  * domain into one of its own, and the VMD driver de-muxes these for the
 160  * handlers sharing that VMD IRQ.  The vmd irq_domain provides the operations
 161  * and irq_chip to set this up.
 162  */
 163 static void vmd_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 164 {
 165         struct vmd_irq *vmdirq = data->chip_data;
 166         struct vmd_irq_list *irq = vmdirq->irq;
 167         struct vmd_dev *vmd = irq_data_get_irq_handler_data(data);
 168
 169         memset(msg, 0, sizeof(*msg));
 170         msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
 171         msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
 172         msg->arch_addr_lo.destid_0_7 = index_from_irqs(vmd, irq);
 173 }
 174
 175 /*
 176  * We rely on MSI_FLAG_USE_DEF_CHIP_OPS to set the IRQ mask/unmask ops.
 177  */
 178 static void vmd_irq_enable(struct irq_data *data)
 179 {
 180         struct vmd_irq *vmdirq = data->chip_data;
 181         unsigned long flags;
 182
 183         raw_spin_lock_irqsave(&list_lock, flags);
 184         WARN_ON(vmdirq->enabled);
 185         list_add_tail_rcu(&vmdirq->node, &vmdirq->irq->irq_list);
 186         vmdirq->enabled = true;
 187         raw_spin_unlock_irqrestore(&list_lock, flags);
 188
 189         data->chip->irq_unmask(data);
 190 }
 191
 192 static void vmd_irq_disable(struct irq_data *data)
 193 {
 194         struct vmd_irq *vmdirq = data->chip_data;
 195         unsigned long flags;
 196
 197         data->chip->irq_mask(data);
 198
 199         raw_spin_lock_irqsave(&list_lock, flags);
 200         if (vmdirq->enabled) {
 201                 list_del_rcu(&vmdirq->node);
 202                 vmdirq->enabled = false;
 203         }
 204         raw_spin_unlock_irqrestore(&list_lock, flags);
 205 }
 206
 207 /*
 208  * XXX: Stubbed until we develop acceptable way to not create conflicts with
 209  * other devices sharing the same vector.
 210  */
 211 static int vmd_irq_set_affinity(struct irq_data *data,
 212                                 const struct cpumask *dest, bool force)
 213 {
 214         return -EINVAL;
 215 }
 216
 217 static struct irq_chip vmd_msi_controller = {
 218         .name                   = "VMD-MSI",
 219         .irq_enable             = vmd_irq_enable,
 220         .irq_disable            = vmd_irq_disable,
 221         .irq_compose_msi_msg    = vmd_compose_msi_msg,
 222         .irq_set_affinity       = vmd_irq_set_affinity,
 223 };
 224
 225 static irq_hw_number_t vmd_get_hwirq(struct msi_domain_info *info,
 226                                      msi_alloc_info_t *arg)
 227 {
 228         return 0;
 229 }
 230
 231 /*
 232  * XXX: We can be even smarter selecting the best IRQ once we solve the
 233  * affinity problem.
 234  */
 235 static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd, struct msi_desc *desc)
 236 {
 237         unsigned long flags;
 238         int i, best;
 239
 240         if (vmd->msix_count == 1 + vmd->first_vec)
 241                 return &vmd->irqs[vmd->first_vec];
 242
 243         /*
 244          * White list for fast-interrupt handlers. All others will share the
 245          * "slow" interrupt vector.
 246          */
 247         switch (msi_desc_to_pci_dev(desc)->class) {
 248         case PCI_CLASS_STORAGE_EXPRESS:
 249                 break;
 250         default:
 251                 return &vmd->irqs[vmd->first_vec];
 252         }
 253
 254         raw_spin_lock_irqsave(&list_lock, flags);
 255         best = vmd->first_vec + 1;
 256         for (i = best; i < vmd->msix_count; i++)
 257                 if (vmd->irqs[i].count < vmd->irqs[best].count)
 258                         best = i;
 259         vmd->irqs[best].count++;
 260         raw_spin_unlock_irqrestore(&list_lock, flags);
 261
 262         return &vmd->irqs[best];
 263 }
 264
 265 static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info,
 266                         unsigned int virq, irq_hw_number_t hwirq,
 267                         msi_alloc_info_t *arg)
 268 {
 269         struct msi_desc *desc = arg->desc;
 270         struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(desc)->bus);
 271         struct vmd_irq *vmdirq = kzalloc(sizeof(*vmdirq), GFP_KERNEL);
 272
 273         if (!vmdirq)
 274                 return -ENOMEM;
 275
 276         INIT_LIST_HEAD(&vmdirq->node);
 277         vmdirq->irq = vmd_next_irq(vmd, desc);
 278         vmdirq->virq = virq;
 279
 280         irq_domain_set_info(domain, virq, vmdirq->irq->virq, info->chip, vmdirq,
 281                             handle_untracked_irq, vmd, NULL);
 282         return 0;
 283 }
 284
 285 static void vmd_msi_free(struct irq_domain *domain,
 286                         struct msi_domain_info *info, unsigned int virq)
 287 {
 288         struct vmd_irq *vmdirq = irq_get_chip_data(virq);
 289         unsigned long flags;
 290
 291         synchronize_srcu(&vmdirq->irq->srcu);
 292
 293         /* XXX: Potential optimization to rebalance */
 294         raw_spin_lock_irqsave(&list_lock, flags);
 295         vmdirq->irq->count--;
 296         raw_spin_unlock_irqrestore(&list_lock, flags);
 297
 298         kfree(vmdirq);
 299 }
 300
 301 static int vmd_msi_prepare(struct irq_domain *domain, struct device *dev,
 302                            int nvec, msi_alloc_info_t *arg)
 303 {
 304         struct pci_dev *pdev = to_pci_dev(dev);
 305         struct vmd_dev *vmd = vmd_from_bus(pdev->bus);
 306
 307         if (nvec > vmd->msix_count)
 308                 return vmd->msix_count;
 309
 310         memset(arg, 0, sizeof(*arg));
 311         return 0;
 312 }
 313
 314 static void vmd_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
 315 {
 316         arg->desc = desc;
 317 }
 318
 319 static struct msi_domain_ops vmd_msi_domain_ops = {
 320         .get_hwirq      = vmd_get_hwirq,
 321         .msi_init       = vmd_msi_init,
 322         .msi_free       = vmd_msi_free,
 323         .msi_prepare    = vmd_msi_prepare,
 324         .set_desc       = vmd_set_desc,
 325 };
 326
 327 static struct msi_domain_info vmd_msi_domain_info = {
 328         .flags          = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
 329                           MSI_FLAG_PCI_MSIX,
 330         .ops            = &vmd_msi_domain_ops,
 331         .chip           = &vmd_msi_controller,
 332 };
 333
 334 static void vmd_set_msi_remapping(struct vmd_dev *vmd, bool enable)
 335 {
 336         u16 reg;
 337
 338         pci_read_config_word(vmd->dev, PCI_REG_VMCONFIG, &reg);
 339         reg = enable ? (reg & ~VMCONFIG_MSI_REMAP) :
 340                        (reg | VMCONFIG_MSI_REMAP);
 341         pci_write_config_word(vmd->dev, PCI_REG_VMCONFIG, reg);
 342 }
 343
 344 static int vmd_create_irq_domain(struct vmd_dev *vmd)
 345 {
 346         struct fwnode_handle *fn;
 347
 348         fn = irq_domain_alloc_named_id_fwnode("VMD-MSI", vmd->sysdata.domain);
 349         if (!fn)
 350                 return -ENODEV;
 351
 352         vmd->irq_domain = pci_msi_create_irq_domain(fn, &vmd_msi_domain_info, NULL);
 353         if (!vmd->irq_domain) {
 354                 irq_domain_free_fwnode(fn);
 355                 return -ENODEV;
 356         }
 357
 358         return 0;
 359 }
 360
 361 static void vmd_remove_irq_domain(struct vmd_dev *vmd)
 362 {
 363         /*
 364          * Some production BIOS won't enable remapping between soft reboots.
 365          * Ensure remapping is restored before unloading the driver.
 366          */
 367         if (!vmd->msix_count)
 368                 vmd_set_msi_remapping(vmd, true);
 369
 370         if (vmd->irq_domain) {
 371                 struct fwnode_handle *fn = vmd->irq_domain->fwnode;
 372
 373                 irq_domain_remove(vmd->irq_domain);
 374                 irq_domain_free_fwnode(fn);
 375         }
 376 }
 377
 378 static void __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
 379                                   unsigned int devfn, int reg, int len)
 380 {
 381         unsigned int busnr_ecam = bus->number - vmd->busn_start;
 382         u32 offset = PCIE_ECAM_OFFSET(busnr_ecam, devfn, reg);
 383
 384         if (offset + len >= resource_size(&vmd->dev->resource[VMD_CFGBAR]))
 385                 return NULL;
 386
 387         return vmd->cfgbar + offset;
 388 }
 389
 390 /*
 391  * CPU may deadlock if config space is not serialized on some versions of this
 392  * hardware, so all config space access is done under a spinlock.
 393  */
 394 static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
 395                         int len, u32 *value)
 396 {
 397         struct vmd_dev *vmd = vmd_from_bus(bus);
 398         void __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
 399         unsigned long flags;
 400         int ret = 0;
 401
 402         if (!addr)
 403                 return -EFAULT;
 404
 405         spin_lock_irqsave(&vmd->cfg_lock, flags);
 406         switch (len) {
 407         case 1:
 408                 *value = readb(addr);
 409                 break;
 410         case 2:
 411                 *value = readw(addr);
 412                 break;
 413         case 4:
 414                 *value = readl(addr);
 415                 break;
 416         default:
 417                 ret = -EINVAL;
 418                 break;
 419         }
 420         spin_unlock_irqrestore(&vmd->cfg_lock, flags);
 421         return ret;
 422 }
 423
 424 /*
 425  * VMD h/w converts non-posted config writes to posted memory writes. The
 426  * read-back in this function forces the completion so it returns only after
 427  * the config space was written, as expected.
 428  */
 429 static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg,
 430                          int len, u32 value)
 431 {
 432         struct vmd_dev *vmd = vmd_from_bus(bus);
 433         void __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
 434         unsigned long flags;
 435         int ret = 0;
 436
 437         if (!addr)
 438                 return -EFAULT;
 439
 440         spin_lock_irqsave(&vmd->cfg_lock, flags);
 441         switch (len) {
 442         case 1:
 443                 writeb(value, addr);
 444                 readb(addr);
 445                 break;
 446         case 2:
 447                 writew(value, addr);
 448                 readw(addr);
 449                 break;
 450         case 4:
 451                 writel(value, addr);
 452                 readl(addr);
 453                 break;
 454         default:
 455                 ret = -EINVAL;
 456                 break;
 457         }
 458         spin_unlock_irqrestore(&vmd->cfg_lock, flags);
 459         return ret;
 460 }
 461
 462 static struct pci_ops vmd_ops = {
 463         .read           = vmd_pci_read,
 464         .write          = vmd_pci_write,
 465 };
 466
 467 #ifdef CONFIG_ACPI
 468 static struct acpi_device *vmd_acpi_find_companion(struct pci_dev *pci_dev)
 469 {
 470         struct pci_host_bridge *bridge;
 471         u32 busnr, addr;
 472
 473         if (pci_dev->bus->ops != &vmd_ops)
 474                 return NULL;
 475
 476         bridge = pci_find_host_bridge(pci_dev->bus);
 477         busnr = pci_dev->bus->number - bridge->bus->number;
 478         /*
 479          * The address computation below is only applicable to relative bus
 480          * numbers below 32.
 481          */
 482         if (busnr > 31)
 483                 return NULL;
 484
 485         addr = (busnr << 24) | ((u32)pci_dev->devfn << 16) | 0x8000FFFFU;
 486
 487         dev_dbg(&pci_dev->dev, "Looking for ACPI companion (address 0x%x)\n",
 488                 addr);
 489
 490         return acpi_find_child_device(ACPI_COMPANION(bridge->dev.parent), addr,
 491                                       false);
 492 }
 493
 494 static bool hook_installed;
 495
 496 static void vmd_acpi_begin(void)
 497 {
 498         if (pci_acpi_set_companion_lookup_hook(vmd_acpi_find_companion))
 499                 return;
 500
 501         hook_installed = true;
 502 }
 503
 504 static void vmd_acpi_end(void)
 505 {
 506         if (!hook_installed)
 507                 return;
 508
 509         pci_acpi_clear_companion_lookup_hook();
 510         hook_installed = false;
 511 }
 512 #else
 513 static inline void vmd_acpi_begin(void) { }
 514 static inline void vmd_acpi_end(void) { }
 515 #endif /* CONFIG_ACPI */
 516
 517 static void vmd_domain_reset(struct vmd_dev *vmd)
 518 {
 519         u16 bus, max_buses = resource_size(&vmd->resources[0]);
 520         u8 dev, functions, fn, hdr_type;
 521         char __iomem *base;
 522
 523         for (bus = 0; bus < max_buses; bus++) {
 524                 for (dev = 0; dev < 32; dev++) {
 525                         base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
 526                                                 PCI_DEVFN(dev, 0), 0);
 527
 528                         hdr_type = readb(base + PCI_HEADER_TYPE) &
 529                                          PCI_HEADER_TYPE_MASK;
 530
 531                         functions = (hdr_type & 0x80) ? 8 : 1;
 532                         for (fn = 0; fn < functions; fn++) {
 533                                 base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
 534                                                 PCI_DEVFN(dev, fn), 0);
 535
 536                                 hdr_type = readb(base + PCI_HEADER_TYPE) &
 537                                                 PCI_HEADER_TYPE_MASK;
 538
 539                                 if (hdr_type != PCI_HEADER_TYPE_BRIDGE ||
 540                                     (readw(base + PCI_CLASS_DEVICE) !=
 541                                      PCI_CLASS_BRIDGE_PCI))
 542                                         continue;
 543
 544                                 /*
 545                                  * Temporarily disable the I/O range before updating
 546                                  * PCI_IO_BASE.
 547                                  */
 548                                 writel(0x0000ffff, base + PCI_IO_BASE_UPPER16);
 549                                 /* Update lower 16 bits of I/O base/limit */
 550                                 writew(0x00f0, base + PCI_IO_BASE);
 551                                 /* Update upper 16 bits of I/O base/limit */
 552                                 writel(0, base + PCI_IO_BASE_UPPER16);
 553
 554                                 /* MMIO Base/Limit */
 555                                 writel(0x0000fff0, base + PCI_MEMORY_BASE);
 556
 557                                 /* Prefetchable MMIO Base/Limit */
 558                                 writel(0, base + PCI_PREF_LIMIT_UPPER32);
 559                                 writel(0x0000fff0, base + PCI_PREF_MEMORY_BASE);
 560                                 writel(0xffffffff, base + PCI_PREF_BASE_UPPER32);
 561                         }
 562                 }
 563         }
 564 }
 565
 566 static void vmd_attach_resources(struct vmd_dev *vmd)
 567 {
 568         vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[1];
 569         vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[2];
 570 }
 571
 572 static void vmd_detach_resources(struct vmd_dev *vmd)
 573 {
 574         vmd->dev->resource[VMD_MEMBAR1].child = NULL;
 575         vmd->dev->resource[VMD_MEMBAR2].child = NULL;
 576 }
 577
 578 /*
 579  * VMD domains start at 0x10000 to not clash with ACPI _SEG domains.
 580  * Per ACPI r6.0, sec 6.5.6,  _SEG returns an integer, of which the lower
 581  * 16 bits are the PCI Segment Group (domain) number.  Other bits are
 582  * currently reserved.
 583  */
 584 static int vmd_find_free_domain(void)
 585 {
 586         int domain = 0xffff;
 587         struct pci_bus *bus = NULL;
 588
 589         while ((bus = pci_find_next_bus(bus)) != NULL)
 590                 domain = max_t(int, domain, pci_domain_nr(bus));
 591         return domain + 1;
 592 }
 593
 594 static int vmd_get_phys_offsets(struct vmd_dev *vmd, bool native_hint,
 595                                 resource_size_t *offset1,
 596                                 resource_size_t *offset2)
 597 {
 598         struct pci_dev *dev = vmd->dev;
 599         u64 phys1, phys2;
 600
 601         if (native_hint) {
 602                 u32 vmlock;
 603                 int ret;
 604
 605                 ret = pci_read_config_dword(dev, PCI_REG_VMLOCK, &vmlock);
 606                 if (ret || PCI_POSSIBLE_ERROR(vmlock))
 607                         return -ENODEV;
 608
 609                 if (MB2_SHADOW_EN(vmlock)) {
 610                         void __iomem *membar2;
 611
 612                         membar2 = pci_iomap(dev, VMD_MEMBAR2, 0);
 613                         if (!membar2)
 614                                 return -ENOMEM;
 615                         phys1 = readq(membar2 + MB2_SHADOW_OFFSET);
 616                         phys2 = readq(membar2 + MB2_SHADOW_OFFSET + 8);
 617                         pci_iounmap(dev, membar2);
 618                 } else
 619                         return 0;
 620         } else {
 621                 /* Hypervisor-Emulated Vendor-Specific Capability */
 622                 int pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
 623                 u32 reg, regu;
 624
 625                 pci_read_config_dword(dev, pos + 4, &reg);
 626
 627                 /* "SHDW" */
 628                 if (pos && reg == 0x53484457) {
 629                         pci_read_config_dword(dev, pos + 8, &reg);
 630                         pci_read_config_dword(dev, pos + 12, &regu);
 631                         phys1 = (u64) regu << 32 | reg;
 632
 633                         pci_read_config_dword(dev, pos + 16, &reg);
 634                         pci_read_config_dword(dev, pos + 20, &regu);
 635                         phys2 = (u64) regu << 32 | reg;
 636                 } else
 637                         return 0;
 638         }
 639
 640         *offset1 = dev->resource[VMD_MEMBAR1].start -
 641                         (phys1 & PCI_BASE_ADDRESS_MEM_MASK);
 642         *offset2 = dev->resource[VMD_MEMBAR2].start -
 643                         (phys2 & PCI_BASE_ADDRESS_MEM_MASK);
 644
 645         return 0;
 646 }
 647
 648 static int vmd_get_bus_number_start(struct vmd_dev *vmd)
 649 {
 650         struct pci_dev *dev = vmd->dev;
 651         u16 reg;
 652
 653         pci_read_config_word(dev, PCI_REG_VMCAP, &reg);
 654         if (BUS_RESTRICT_CAP(reg)) {
 655                 pci_read_config_word(dev, PCI_REG_VMCONFIG, &reg);
 656
 657                 switch (BUS_RESTRICT_CFG(reg)) {
 658                 case 0:
 659                         vmd->busn_start = 0;
 660                         break;
 661                 case 1:
 662                         vmd->busn_start = 128;
 663                         break;
 664                 case 2:
 665                         vmd->busn_start = 224;
 666                         break;
 667                 default:
 668                         pci_err(dev, "Unknown Bus Offset Setting (%d)\n",
 669                                 BUS_RESTRICT_CFG(reg));
 670                         return -ENODEV;
 671                 }
 672         }
 673
 674         return 0;
 675 }
 676
 677 static irqreturn_t vmd_irq(int irq, void *data)
 678 {
 679         struct vmd_irq_list *irqs = data;
 680         struct vmd_irq *vmdirq;
 681         int idx;
 682
 683         idx = srcu_read_lock(&irqs->srcu);
 684         list_for_each_entry_rcu(vmdirq, &irqs->irq_list, node)
 685                 generic_handle_irq(vmdirq->virq);
 686         srcu_read_unlock(&irqs->srcu, idx);
 687
 688         return IRQ_HANDLED;
 689 }
 690
 691 static int vmd_alloc_irqs(struct vmd_dev *vmd)
 692 {
 693         struct pci_dev *dev = vmd->dev;
 694         int i, err;
 695
 696         vmd->msix_count = pci_msix_vec_count(dev);
 697         if (vmd->msix_count < 0)
 698                 return -ENODEV;
 699
 700         vmd->msix_count = pci_alloc_irq_vectors(dev, vmd->first_vec + 1,
 701                                                 vmd->msix_count, PCI_IRQ_MSIX);
 702         if (vmd->msix_count < 0)
 703                 return vmd->msix_count;
 704
 705         vmd->irqs = devm_kcalloc(&dev->dev, vmd->msix_count, sizeof(*vmd->irqs),
 706                                  GFP_KERNEL);
 707         if (!vmd->irqs)
 708                 return -ENOMEM;
 709
 710         for (i = 0; i < vmd->msix_count; i++) {
 711                 err = init_srcu_struct(&vmd->irqs[i].srcu);
 712                 if (err)
 713                         return err;
 714
 715                 INIT_LIST_HEAD(&vmd->irqs[i].irq_list);
 716                 vmd->irqs[i].virq = pci_irq_vector(dev, i);
 717                 err = devm_request_irq(&dev->dev, vmd->irqs[i].virq,
 718                                        vmd_irq, IRQF_NO_THREAD,
 719                                        vmd->name, &vmd->irqs[i]);
 720                 if (err)
 721                         return err;
 722         }
 723
 724         return 0;
 725 }
 726
 727 /*
 728  * Since VMD is an aperture to regular PCIe root ports, only allow it to
 729  * control features that the OS is allowed to control on the physical PCI bus.
 730  */
 731 static void vmd_copy_host_bridge_flags(struct pci_host_bridge *root_bridge,
 732                                        struct pci_host_bridge *vmd_bridge)
 733 {
 734         vmd_bridge->native_pcie_hotplug = root_bridge->native_pcie_hotplug;
 735         vmd_bridge->native_shpc_hotplug = root_bridge->native_shpc_hotplug;
 736         vmd_bridge->native_aer = root_bridge->native_aer;
 737         vmd_bridge->native_pme = root_bridge->native_pme;
 738         vmd_bridge->native_ltr = root_bridge->native_ltr;
 739         vmd_bridge->native_dpc = root_bridge->native_dpc;
 740 }
 741
 742 /*
 743  * Enable ASPM and LTR settings on devices that aren't configured by BIOS.
 744  */
 745 static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata)
 746 {
 747         unsigned long features = *(unsigned long *)userdata;
 748         u16 ltr = VMD_BIOS_PM_QUIRK_LTR;
 749         u32 ltr_reg;
 750         int pos;
 751
 752         if (!(features & VMD_FEAT_BIOS_PM_QUIRK))
 753                 return 0;
 754
 755         pci_enable_link_state(pdev, PCIE_LINK_STATE_ALL);
 756
 757         pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR);
 758         if (!pos)
 759                 return 0;
 760
 761         /*
 762          * Skip if the max snoop LTR is non-zero, indicating BIOS has set it
 763          * so the LTR quirk is not needed.
 764          */
 765         pci_read_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, &ltr_reg);
 766         if (!!(ltr_reg & (PCI_LTR_VALUE_MASK | PCI_LTR_SCALE_MASK)))
 767                 return 0;
 768
 769         /*
 770          * Set the default values to the maximum required by the platform to
 771          * allow the deepest power management savings. Write as a DWORD where
 772          * the lower word is the max snoop latency and the upper word is the
 773          * max non-snoop latency.
 774          */
 775         ltr_reg = (ltr << 16) | ltr;
 776         pci_write_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, ltr_reg);
 777         pci_info(pdev, "VMD: Default LTR value set by driver\n");
 778
 779         return 0;
 780 }
 781
 782 static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 783 {
 784         struct pci_sysdata *sd = &vmd->sysdata;
 785         struct resource *res;
 786         u32 upper_bits;
 787         unsigned long flags;
 788         LIST_HEAD(resources);
 789         resource_size_t offset[2] = {0};
 790         resource_size_t membar2_offset = 0x2000;
 791         struct pci_bus *child;
 792         struct pci_dev *dev;
 793         int ret;
 794
 795         /*
 796          * Shadow registers may exist in certain VMD device ids which allow
 797          * guests to correctly assign host physical addresses to the root ports
 798          * and child devices. These registers will either return the host value
 799          * or 0, depending on an enable bit in the VMD device.
 800          */
 801         if (features & VMD_FEAT_HAS_MEMBAR_SHADOW) {
 802                 membar2_offset = MB2_SHADOW_OFFSET + MB2_SHADOW_SIZE;
 803                 ret = vmd_get_phys_offsets(vmd, true, &offset[0], &offset[1]);
 804                 if (ret)
 805                         return ret;
 806         } else if (features & VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP) {
 807                 ret = vmd_get_phys_offsets(vmd, false, &offset[0], &offset[1]);
 808                 if (ret)
 809                         return ret;
 810         }
 811
 812         /*
 813          * Certain VMD devices may have a root port configuration option which
 814          * limits the bus range to between 0-127, 128-255, or 224-255
 815          */
 816         if (features & VMD_FEAT_HAS_BUS_RESTRICTIONS) {
 817                 ret = vmd_get_bus_number_start(vmd);
 818                 if (ret)
 819                         return ret;
 820         }
 821
 822         res = &vmd->dev->resource[VMD_CFGBAR];
 823         vmd->resources[0] = (struct resource) {
 824                 .name  = "VMD CFGBAR",
 825                 .start = vmd->busn_start,
 826                 .end   = vmd->busn_start + (resource_size(res) >> 20) - 1,
 827                 .flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
 828         };
 829
 830         /*
 831          * If the window is below 4GB, clear IORESOURCE_MEM_64 so we can
 832          * put 32-bit resources in the window.
 833          *
 834          * There's no hardware reason why a 64-bit window *couldn't*
 835          * contain a 32-bit resource, but pbus_size_mem() computes the
 836          * bridge window size assuming a 64-bit window will contain no
 837          * 32-bit resources.  __pci_assign_resource() enforces that
 838          * artificial restriction to make sure everything will fit.
 839          *
 840          * The only way we could use a 64-bit non-prefetchable MEMBAR is
 841          * if its address is <4GB so that we can convert it to a 32-bit
 842          * resource.  To be visible to the host OS, all VMD endpoints must
 843          * be initially configured by platform BIOS, which includes setting
 844          * up these resources.  We can assume the device is configured
 845          * according to the platform needs.
 846          */
 847         res = &vmd->dev->resource[VMD_MEMBAR1];
 848         upper_bits = upper_32_bits(res->end);
 849         flags = res->flags & ~IORESOURCE_SIZEALIGN;
 850         if (!upper_bits)
 851                 flags &= ~IORESOURCE_MEM_64;
 852         vmd->resources[1] = (struct resource) {
 853                 .name  = "VMD MEMBAR1",
 854                 .start = res->start,
 855                 .end   = res->end,
 856                 .flags = flags,
 857                 .parent = res,
 858         };
 859
 860         res = &vmd->dev->resource[VMD_MEMBAR2];
 861         upper_bits = upper_32_bits(res->end);
 862         flags = res->flags & ~IORESOURCE_SIZEALIGN;
 863         if (!upper_bits)
 864                 flags &= ~IORESOURCE_MEM_64;
 865         vmd->resources[2] = (struct resource) {
 866                 .name  = "VMD MEMBAR2",
 867                 .start = res->start + membar2_offset,
 868                 .end   = res->end,
 869                 .flags = flags,
 870                 .parent = res,
 871         };
 872
 873         sd->vmd_dev = vmd->dev;
 874         sd->domain = vmd_find_free_domain();
 875         if (sd->domain < 0)
 876                 return sd->domain;
 877
 878         sd->node = pcibus_to_node(vmd->dev->bus);
 879
 880         /*
 881          * Currently MSI remapping must be enabled in guest passthrough mode
 882          * due to some missing interrupt remapping plumbing. This is probably
 883          * acceptable because the guest is usually CPU-limited and MSI
 884          * remapping doesn't become a performance bottleneck.
 885          */
 886         if (!(features & VMD_FEAT_CAN_BYPASS_MSI_REMAP) ||
 887             offset[0] || offset[1]) {
 888                 ret = vmd_alloc_irqs(vmd);
 889                 if (ret)
 890                         return ret;
 891
 892                 vmd_set_msi_remapping(vmd, true);
 893
 894                 ret = vmd_create_irq_domain(vmd);
 895                 if (ret)
 896                         return ret;
 897
 898                 /*
 899                  * Override the IRQ domain bus token so the domain can be
 900                  * distinguished from a regular PCI/MSI domain.
 901                  */
 902                 irq_domain_update_bus_token(vmd->irq_domain, DOMAIN_BUS_VMD_MSI);
 903         } else {
 904                 vmd_set_msi_remapping(vmd, false);
 905         }
 906
 907         pci_add_resource(&resources, &vmd->resources[0]);
 908         pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
 909         pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
 910
 911         vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
 912                                        &vmd_ops, sd, &resources);
 913         if (!vmd->bus) {
 914                 pci_free_resource_list(&resources);
 915                 vmd_remove_irq_domain(vmd);
 916                 return -ENODEV;
 917         }
 918
 919         vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
 920                                    to_pci_host_bridge(vmd->bus->bridge));
 921
 922         vmd_attach_resources(vmd);
 923         if (vmd->irq_domain)
 924                 dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
 925         else
 926                 dev_set_msi_domain(&vmd->bus->dev,
 927                                    dev_get_msi_domain(&vmd->dev->dev));
 928
 929         vmd_acpi_begin();
 930
 931         pci_scan_child_bus(vmd->bus);
 932         vmd_domain_reset(vmd);
 933
 934         /* When Intel VMD is enabled, the OS does not discover the Root Ports
 935          * owned by Intel VMD within the MMCFG space. pci_reset_bus() applies
 936          * a reset to the parent of the PCI device supplied as argument. This
 937          * is why we pass a child device, so the reset can be triggered at
 938          * the Intel bridge level and propagated to all the children in the
 939          * hierarchy.
 940          */
 941         list_for_each_entry(child, &vmd->bus->children, node) {
 942                 if (!list_empty(&child->devices)) {
 943                         dev = list_first_entry(&child->devices,
 944                                                struct pci_dev, bus_list);
 945                         ret = pci_reset_bus(dev);
 946                         if (ret)
 947                                 pci_warn(dev, "can't reset device: %d\n", ret);
 948
 949                         break;
 950                 }
 951         }
 952
 953         pci_assign_unassigned_bus_resources(vmd->bus);
 954
 955         pci_walk_bus(vmd->bus, vmd_pm_enable_quirk, &features);
 956
 957         /*
 958          * VMD root buses are virtual and don't return true on pci_is_pcie()
 959          * and will fail pcie_bus_configure_settings() early. It can instead be
 960          * run on each of the real root ports.
 961          */
 962         list_for_each_entry(child, &vmd->bus->children, node)
 963                 pcie_bus_configure_settings(child);
 964
 965         pci_bus_add_devices(vmd->bus);
 966
 967         vmd_acpi_end();
 968
 969         WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
 970                                "domain"), "Can't create symlink to domain\n");
 971         return 0;
 972 }
 973
 974 static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 975 {
 976         unsigned long features = (unsigned long) id->driver_data;
 977         struct vmd_dev *vmd;
 978         int err;
 979
 980         if (resource_size(&dev->resource[VMD_CFGBAR]) < (1 << 20))
 981                 return -ENOMEM;
 982
 983         vmd = devm_kzalloc(&dev->dev, sizeof(*vmd), GFP_KERNEL);
 984         if (!vmd)
 985                 return -ENOMEM;
 986
 987         vmd->dev = dev;
 988         vmd->instance = ida_simple_get(&vmd_instance_ida, 0, 0, GFP_KERNEL);
 989         if (vmd->instance < 0)
 990                 return vmd->instance;
 991
 992         vmd->name = devm_kasprintf(&dev->dev, GFP_KERNEL, "vmd%d",
 993                                    vmd->instance);
 994         if (!vmd->name) {
 995                 err = -ENOMEM;
 996                 goto out_release_instance;
 997         }
 998
 999         err = pcim_enable_device(dev);
1000         if (err < 0)
1001                 goto out_release_instance;
1002
1003         vmd->cfgbar = pcim_iomap(dev, VMD_CFGBAR, 0);
1004         if (!vmd->cfgbar) {
1005                 err = -ENOMEM;
1006                 goto out_release_instance;
1007         }
1008
1009         pci_set_master(dev);
1010         if (dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(64)) &&
1011             dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32))) {
1012                 err = -ENODEV;
1013                 goto out_release_instance;
1014         }
1015
1016         if (features & VMD_FEAT_OFFSET_FIRST_VECTOR)
1017                 vmd->first_vec = 1;
1018
1019         spin_lock_init(&vmd->cfg_lock);
1020         pci_set_drvdata(dev, vmd);
1021         err = vmd_enable_domain(vmd, features);
1022         if (err)
1023                 goto out_release_instance;
1024
1025         dev_info(&vmd->dev->dev, "Bound to PCI domain %04x\n",
1026                  vmd->sysdata.domain);
1027         return 0;
1028
1029  out_release_instance:
1030         ida_simple_remove(&vmd_instance_ida, vmd->instance);
1031         return err;
1032 }
1033
1034 static void vmd_cleanup_srcu(struct vmd_dev *vmd)
1035 {
1036         int i;
1037
1038         for (i = 0; i < vmd->msix_count; i++)
1039                 cleanup_srcu_struct(&vmd->irqs[i].srcu);
1040 }
1041
1042 static void vmd_remove(struct pci_dev *dev)
1043 {
1044         struct vmd_dev *vmd = pci_get_drvdata(dev);
1045
1046         sysfs_remove_link(&vmd->dev->dev.kobj, "domain");
1047         pci_stop_root_bus(vmd->bus);
1048         pci_remove_root_bus(vmd->bus);
1049         vmd_cleanup_srcu(vmd);
1050         vmd_detach_resources(vmd);
1051         vmd_remove_irq_domain(vmd);
1052         ida_simple_remove(&vmd_instance_ida, vmd->instance);
1053 }
1054
1055 static void vmd_shutdown(struct pci_dev *dev)
1056 {
1057         struct vmd_dev *vmd = pci_get_drvdata(dev);
1058
1059         vmd_remove_irq_domain(vmd);
1060 }
1061
1062 #ifdef CONFIG_PM_SLEEP
1063 static int vmd_suspend(struct device *dev)
1064 {
1065         struct pci_dev *pdev = to_pci_dev(dev);
1066         struct vmd_dev *vmd = pci_get_drvdata(pdev);
1067         int i;
1068
1069         for (i = 0; i < vmd->msix_count; i++)
1070                 devm_free_irq(dev, vmd->irqs[i].virq, &vmd->irqs[i]);
1071
1072         return 0;
1073 }
1074
1075 static int vmd_resume(struct device *dev)
1076 {
1077         struct pci_dev *pdev = to_pci_dev(dev);
1078         struct vmd_dev *vmd = pci_get_drvdata(pdev);
1079         int err, i;
1080
1081        if (vmd->irq_domain)
1082                vmd_set_msi_remapping(vmd, true);
1083        else
1084                vmd_set_msi_remapping(vmd, false);
1085
1086         for (i = 0; i < vmd->msix_count; i++) {
1087                 err = devm_request_irq(dev, vmd->irqs[i].virq,
1088                                        vmd_irq, IRQF_NO_THREAD,
1089                                        vmd->name, &vmd->irqs[i]);
1090                 if (err)
1091                         return err;
1092         }
1093
1094         return 0;
1095 }
1096 #endif
1097 static SIMPLE_DEV_PM_OPS(vmd_dev_pm_ops, vmd_suspend, vmd_resume);
1098
1099 static const struct pci_device_id vmd_ids[] = {
1100         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_201D),
1101                 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP,},
1102         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_28C0),
1103                 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW |
1104                                 VMD_FEAT_HAS_BUS_RESTRICTIONS |
1105                                 VMD_FEAT_CAN_BYPASS_MSI_REMAP,},
1106         {PCI_VDEVICE(INTEL, 0x467f),
1107                 .driver_data = VMD_FEATS_CLIENT,},
1108         {PCI_VDEVICE(INTEL, 0x4c3d),
1109                 .driver_data = VMD_FEATS_CLIENT,},
1110         {PCI_VDEVICE(INTEL, 0xa77f),
1111                 .driver_data = VMD_FEATS_CLIENT,},
1112         {PCI_VDEVICE(INTEL, 0x7d0b),
1113                 .driver_data = VMD_FEATS_CLIENT,},
1114         {PCI_VDEVICE(INTEL, 0xad0b),
1115                 .driver_data = VMD_FEATS_CLIENT,},
1116         {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B),
1117                 .driver_data = VMD_FEATS_CLIENT,},
1118         {0,}
1119 };
1120 MODULE_DEVICE_TABLE(pci, vmd_ids);
1121
1122 static struct pci_driver vmd_drv = {
1123         .name           = "vmd",
1124         .id_table       = vmd_ids,
1125         .probe          = vmd_probe,
1126         .remove         = vmd_remove,
1127         .shutdown       = vmd_shutdown,
1128         .driver         = {
1129                 .pm     = &vmd_dev_pm_ops,
1130         },
1131 };
1132 module_pci_driver(vmd_drv);
1133
1134 MODULE_AUTHOR("Intel Corporation");
1135 MODULE_LICENSE("GPL v2");
1136 MODULE_VERSION("0.6");