arch/x86/pci/xen.c

   1 /*
   2  * Xen PCI - handle PCI (INTx) and MSI infrastructure calls for PV, HVM and
   3  * initial domain support. We also handle the DSDT _PRT callbacks for GSI's
   4  * used in HVM and initial domain mode (PV does not parse ACPI, so it has no
   5  * concept of GSIs). Under PV we hook under the pnbbios API for IRQs and
   6  * 0xcf8 PCI configuration read/write.
   7  *
   8  *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
   9  *           Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
  10  *           Stefano Stabellini <stefano.stabellini@eu.citrix.com>
  11  */
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/pci.h>
  15 #include <linux/acpi.h>
  16
  17 #include <linux/io.h>
  18 #include <asm/io_apic.h>
  19 #include <asm/pci_x86.h>
  20
  21 #include <asm/xen/hypervisor.h>
  22
  23 #include <xen/features.h>
  24 #include <xen/events.h>
  25 #include <asm/xen/pci.h>
  26
  27 static int xen_pcifront_enable_irq(struct pci_dev *dev)
  28 {
  29         int rc;
  30         int share = 1;
  31         int pirq;
  32         u8 gsi;
  33
  34         rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
  35         if (rc < 0) {
  36                 dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
  37                          rc);
  38                 return rc;
  39         }
  40         /* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/
  41         pirq = gsi;
  42
  43         if (gsi < NR_IRQS_LEGACY)
  44                 share = 0;
  45
  46         rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
  47         if (rc < 0) {
  48                 dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n",
  49                          gsi, pirq, rc);
  50                 return rc;
  51         }
  52
  53         dev->irq = rc;
  54         dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
  55         return 0;
  56 }
  57
  58 #ifdef CONFIG_ACPI
  59 static int xen_register_pirq(u32 gsi, int gsi_override, int triggering,
  60                              bool set_pirq)
  61 {
  62         int rc, pirq = -1, irq = -1;
  63         struct physdev_map_pirq map_irq;
  64         int shareable = 0;
  65         char *name;
  66
  67         irq = xen_irq_from_gsi(gsi);
  68         if (irq > 0)
  69                 return irq;
  70
  71         if (set_pirq)
  72                 pirq = gsi;
  73
  74         map_irq.domid = DOMID_SELF;
  75         map_irq.type = MAP_PIRQ_TYPE_GSI;
  76         map_irq.index = gsi;
  77         map_irq.pirq = pirq;
  78
  79         rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
  80         if (rc) {
  81                 printk(KERN_WARNING "xen map irq failed %d\n", rc);
  82                 return -1;
  83         }
  84
  85         if (triggering == ACPI_EDGE_SENSITIVE) {
  86                 shareable = 0;
  87                 name = "ioapic-edge";
  88         } else {
  89                 shareable = 1;
  90                 name = "ioapic-level";
  91         }
  92
  93         if (gsi_override >= 0)
  94                 gsi = gsi_override;
  95
  96         irq = xen_bind_pirq_gsi_to_irq(gsi, map_irq.pirq, shareable, name);
  97         if (irq < 0)
  98                 goto out;
  99
 100         printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", map_irq.pirq, irq, gsi);
 101 out:
 102         return irq;
 103 }
 104
 105 static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
 106                                      int trigger, int polarity)
 107 {
 108         if (!xen_hvm_domain())
 109                 return -1;
 110
 111         return xen_register_pirq(gsi, -1 /* no GSI override */, trigger,
 112                                  false /* no mapping of GSI to PIRQ */);
 113 }
 114
 115 #ifdef CONFIG_XEN_DOM0
 116 static int xen_register_gsi(u32 gsi, int gsi_override, int triggering, int polarity)
 117 {
 118         int rc, irq;
 119         struct physdev_setup_gsi setup_gsi;
 120
 121         if (!xen_pv_domain())
 122                 return -1;
 123
 124         printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
 125                         gsi, triggering, polarity);
 126
 127         irq = xen_register_pirq(gsi, gsi_override, triggering, true);
 128
 129         setup_gsi.gsi = gsi;
 130         setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
 131         setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
 132
 133         rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
 134         if (rc == -EEXIST)
 135                 printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
 136         else if (rc) {
 137                 printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
 138                                 gsi, rc);
 139         }
 140
 141         return irq;
 142 }
 143
 144 static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
 145                                  int trigger, int polarity)
 146 {
 147         return xen_register_gsi(gsi, -1 /* no GSI override */, trigger, polarity);
 148 }
 149 #endif
 150 #endif
 151
 152 #if defined(CONFIG_PCI_MSI)
 153 #include <linux/msi.h>
 154 #include <asm/msidef.h>
 155
 156 struct xen_pci_frontend_ops *xen_pci_frontend;
 157 EXPORT_SYMBOL_GPL(xen_pci_frontend);
 158
 159 static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 160 {
 161         int irq, ret, i;
 162         struct msi_desc *msidesc;
 163         int *v;
 164
 165         v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL);
 166         if (!v)
 167                 return -ENOMEM;
 168
 169         if (type == PCI_CAP_ID_MSIX)
 170                 ret = xen_pci_frontend_enable_msix(dev, v, nvec);
 171         else
 172                 ret = xen_pci_frontend_enable_msi(dev, v);
 173         if (ret)
 174                 goto error;
 175         i = 0;
 176         list_for_each_entry(msidesc, &dev->msi_list, list) {
 177                 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i], 0,
 178                                                (type == PCI_CAP_ID_MSIX) ?
 179                                                "pcifront-msi-x" :
 180                                                "pcifront-msi",
 181                                                 DOMID_SELF);
 182                 if (irq < 0) {
 183                         ret = irq;
 184                         goto free;
 185                 }
 186                 i++;
 187         }
 188         kfree(v);
 189         return 0;
 190
 191 error:
 192         dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n");
 193 free:
 194         kfree(v);
 195         return ret;
 196 }
 197
 198 #define XEN_PIRQ_MSI_DATA  (MSI_DATA_TRIGGER_EDGE | \
 199                 MSI_DATA_LEVEL_ASSERT | (3 << 8) | MSI_DATA_VECTOR(0))
 200
 201 static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq,
 202                 struct msi_msg *msg)
 203 {
 204         /* We set vector == 0 to tell the hypervisor we don't care about it,
 205          * but we want a pirq setup instead.
 206          * We use the dest_id field to pass the pirq that we want. */
 207         msg->address_hi = MSI_ADDR_BASE_HI | MSI_ADDR_EXT_DEST_ID(pirq);
 208         msg->address_lo =
 209                 MSI_ADDR_BASE_LO |
 210                 MSI_ADDR_DEST_MODE_PHYSICAL |
 211                 MSI_ADDR_REDIRECTION_CPU |
 212                 MSI_ADDR_DEST_ID(pirq);
 213
 214         msg->data = XEN_PIRQ_MSI_DATA;
 215 }
 216
 217 static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 218 {
 219         int irq, pirq;
 220         struct msi_desc *msidesc;
 221         struct msi_msg msg;
 222
 223         list_for_each_entry(msidesc, &dev->msi_list, list) {
 224                 __read_msi_msg(msidesc, &msg);
 225                 pirq = MSI_ADDR_EXT_DEST_ID(msg.address_hi) |
 226                         ((msg.address_lo >> MSI_ADDR_DEST_ID_SHIFT) & 0xff);
 227                 if (msg.data != XEN_PIRQ_MSI_DATA ||
 228                     xen_irq_from_pirq(pirq) < 0) {
 229                         pirq = xen_allocate_pirq_msi(dev, msidesc);
 230                         if (pirq < 0) {
 231                                 irq = -ENODEV;
 232                                 goto error;
 233                         }
 234                         xen_msi_compose_msg(dev, pirq, &msg);
 235                         __write_msi_msg(msidesc, &msg);
 236                         dev_dbg(&dev->dev, "xen: msi bound to pirq=%d\n", pirq);
 237                 } else {
 238                         dev_dbg(&dev->dev,
 239                                 "xen: msi already bound to pirq=%d\n", pirq);
 240                 }
 241                 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq, 0,
 242                                                (type == PCI_CAP_ID_MSIX) ?
 243                                                "msi-x" : "msi",
 244                                                DOMID_SELF);
 245                 if (irq < 0)
 246                         goto error;
 247                 dev_dbg(&dev->dev,
 248                         "xen: msi --> pirq=%d --> irq=%d\n", pirq, irq);
 249         }
 250         return 0;
 251
 252 error:
 253         dev_err(&dev->dev,
 254                 "Xen PCI frontend has not registered MSI/MSI-X support!\n");
 255         return irq;
 256 }
 257
 258 #ifdef CONFIG_XEN_DOM0
 259 static bool __read_mostly pci_seg_supported = true;
 260
 261 static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 262 {
 263         int ret = 0;
 264         struct msi_desc *msidesc;
 265
 266         list_for_each_entry(msidesc, &dev->msi_list, list) {
 267                 struct physdev_map_pirq map_irq;
 268                 domid_t domid;
 269
 270                 domid = ret = xen_find_device_domain_owner(dev);
 271                 /* N.B. Casting int's -ENODEV to uint16_t results in 0xFFED,
 272                  * hence check ret value for < 0. */
 273                 if (ret < 0)
 274                         domid = DOMID_SELF;
 275
 276                 memset(&map_irq, 0, sizeof(map_irq));
 277                 map_irq.domid = domid;
 278                 map_irq.type = MAP_PIRQ_TYPE_MSI_SEG;
 279                 map_irq.index = -1;
 280                 map_irq.pirq = -1;
 281                 map_irq.bus = dev->bus->number |
 282                               (pci_domain_nr(dev->bus) << 16);
 283                 map_irq.devfn = dev->devfn;
 284
 285                 if (type == PCI_CAP_ID_MSIX) {
 286                         int pos;
 287                         u32 table_offset, bir;
 288
 289                         pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
 290
 291                         pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
 292                                               &table_offset);
 293                         bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
 294
 295                         map_irq.table_base = pci_resource_start(dev, bir);
 296                         map_irq.entry_nr = msidesc->msi_attrib.entry_nr;
 297                 }
 298
 299                 ret = -EINVAL;
 300                 if (pci_seg_supported)
 301                         ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
 302                                                     &map_irq);
 303                 if (ret == -EINVAL && !pci_domain_nr(dev->bus)) {
 304                         map_irq.type = MAP_PIRQ_TYPE_MSI;
 305                         map_irq.index = -1;
 306                         map_irq.pirq = -1;
 307                         map_irq.bus = dev->bus->number;
 308                         ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
 309                                                     &map_irq);
 310                         if (ret != -EINVAL)
 311                                 pci_seg_supported = false;
 312                 }
 313                 if (ret) {
 314                         dev_warn(&dev->dev, "xen map irq failed %d for %d domain\n",
 315                                  ret, domid);
 316                         goto out;
 317                 }
 318
 319                 ret = xen_bind_pirq_msi_to_irq(dev, msidesc,
 320                                                map_irq.pirq, map_irq.index,
 321                                                (type == PCI_CAP_ID_MSIX) ?
 322                                                "msi-x" : "msi",
 323                                                 domid);
 324                 if (ret < 0)
 325                         goto out;
 326         }
 327         ret = 0;
 328 out:
 329         return ret;
 330 }
 331
 332 static void xen_initdom_restore_msi_irqs(struct pci_dev *dev, int irq)
 333 {
 334         int ret = 0;
 335
 336         if (pci_seg_supported) {
 337                 struct physdev_pci_device restore_ext;
 338
 339                 restore_ext.seg = pci_domain_nr(dev->bus);
 340                 restore_ext.bus = dev->bus->number;
 341                 restore_ext.devfn = dev->devfn;
 342                 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi_ext,
 343                                         &restore_ext);
 344                 if (ret == -ENOSYS)
 345                         pci_seg_supported = false;
 346                 WARN(ret && ret != -ENOSYS, "restore_msi_ext -> %d\n", ret);
 347         }
 348         if (!pci_seg_supported) {
 349                 struct physdev_restore_msi restore;
 350
 351                 restore.bus = dev->bus->number;
 352                 restore.devfn = dev->devfn;
 353                 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi, &restore);
 354                 WARN(ret && ret != -ENOSYS, "restore_msi -> %d\n", ret);
 355         }
 356 }
 357 #endif
 358
 359 static void xen_teardown_msi_irqs(struct pci_dev *dev)
 360 {
 361         struct msi_desc *msidesc;
 362
 363         msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
 364         if (msidesc->msi_attrib.is_msix)
 365                 xen_pci_frontend_disable_msix(dev);
 366         else
 367                 xen_pci_frontend_disable_msi(dev);
 368
 369         /* Free the IRQ's and the msidesc using the generic code. */
 370         default_teardown_msi_irqs(dev);
 371 }
 372
 373 static void xen_teardown_msi_irq(unsigned int irq)
 374 {
 375         xen_destroy_irq(irq);
 376 }
 377
 378 #endif
 379
 380 int __init pci_xen_init(void)
 381 {
 382         if (!xen_pv_domain() || xen_initial_domain())
 383                 return -ENODEV;
 384
 385         printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n");
 386
 387         pcibios_set_cache_line_size();
 388
 389         pcibios_enable_irq = xen_pcifront_enable_irq;
 390         pcibios_disable_irq = NULL;
 391
 392 #ifdef CONFIG_ACPI
 393         /* Keep ACPI out of the picture */
 394         acpi_noirq = 1;
 395 #endif
 396
 397 #ifdef CONFIG_PCI_MSI
 398         x86_msi.setup_msi_irqs = xen_setup_msi_irqs;
 399         x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
 400         x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
 401 #endif
 402         return 0;
 403 }
 404
 405 int __init pci_xen_hvm_init(void)
 406 {
 407         if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs))
 408                 return 0;
 409
 410 #ifdef CONFIG_ACPI
 411         /*
 412          * We don't want to change the actual ACPI delivery model,
 413          * just how GSIs get registered.
 414          */
 415         __acpi_register_gsi = acpi_register_gsi_xen_hvm;
 416 #endif
 417
 418 #ifdef CONFIG_PCI_MSI
 419         x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs;
 420         x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
 421 #endif
 422         return 0;
 423 }
 424
 425 #ifdef CONFIG_XEN_DOM0
 426 static __init void xen_setup_acpi_sci(void)
 427 {
 428         int rc;
 429         int trigger, polarity;
 430         int gsi = acpi_sci_override_gsi;
 431         int irq = -1;
 432         int gsi_override = -1;
 433
 434         if (!gsi)
 435                 return;
 436
 437         rc = acpi_get_override_irq(gsi, &trigger, &polarity);
 438         if (rc) {
 439                 printk(KERN_WARNING "xen: acpi_get_override_irq failed for acpi"
 440                                 " sci, rc=%d\n", rc);
 441                 return;
 442         }
 443         trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
 444         polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
 445
 446         printk(KERN_INFO "xen: sci override: global_irq=%d trigger=%d "
 447                         "polarity=%d\n", gsi, trigger, polarity);
 448
 449         /* Before we bind the GSI to a Linux IRQ, check whether
 450          * we need to override it with bus_irq (IRQ) value. Usually for
 451          * IRQs below IRQ_LEGACY_IRQ this holds IRQ == GSI, as so:
 452          *  ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level)
 453          * but there are oddballs where the IRQ != GSI:
 454          *  ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level)
 455          * which ends up being: gsi_to_irq[9] == 20
 456          * (which is what acpi_gsi_to_irq ends up calling when starting the
 457          * the ACPI interpreter and keels over since IRQ 9 has not been
 458          * setup as we had setup IRQ 20 for it).
 459          */
 460         if (acpi_gsi_to_irq(gsi, &irq) == 0) {
 461                 /* Use the provided value if it's valid. */
 462                 if (irq >= 0)
 463                         gsi_override = irq;
 464         }
 465
 466         gsi = xen_register_gsi(gsi, gsi_override, trigger, polarity);
 467         printk(KERN_INFO "xen: acpi sci %d\n", gsi);
 468
 469         return;
 470 }
 471
 472 int __init pci_xen_initial_domain(void)
 473 {
 474         int irq;
 475
 476 #ifdef CONFIG_PCI_MSI
 477         x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
 478         x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
 479         x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs;
 480 #endif
 481         xen_setup_acpi_sci();
 482         __acpi_register_gsi = acpi_register_gsi_xen;
 483         /* Pre-allocate legacy irqs */
 484         for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
 485                 int trigger, polarity;
 486
 487                 if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
 488                         continue;
 489
 490                 xen_register_pirq(irq, -1 /* no GSI override */,
 491                         trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE,
 492                         true /* Map GSI to PIRQ */);
 493         }
 494         if (0 == nr_ioapics) {
 495                 for (irq = 0; irq < NR_IRQS_LEGACY; irq++)
 496                         xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic");
 497         }
 498         return 0;
 499 }
 500
 501 struct xen_device_domain_owner {
 502         domid_t domain;
 503         struct pci_dev *dev;
 504         struct list_head list;
 505 };
 506
 507 static DEFINE_SPINLOCK(dev_domain_list_spinlock);
 508 static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
 509
 510 static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
 511 {
 512         struct xen_device_domain_owner *owner;
 513
 514         list_for_each_entry(owner, &dev_domain_list, list) {
 515                 if (owner->dev == dev)
 516                         return owner;
 517         }
 518         return NULL;
 519 }
 520
 521 int xen_find_device_domain_owner(struct pci_dev *dev)
 522 {
 523         struct xen_device_domain_owner *owner;
 524         int domain = -ENODEV;
 525
 526         spin_lock(&dev_domain_list_spinlock);
 527         owner = find_device(dev);
 528         if (owner)
 529                 domain = owner->domain;
 530         spin_unlock(&dev_domain_list_spinlock);
 531         return domain;
 532 }
 533 EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
 534
 535 int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
 536 {
 537         struct xen_device_domain_owner *owner;
 538
 539         owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
 540         if (!owner)
 541                 return -ENODEV;
 542
 543         spin_lock(&dev_domain_list_spinlock);
 544         if (find_device(dev)) {
 545                 spin_unlock(&dev_domain_list_spinlock);
 546                 kfree(owner);
 547                 return -EEXIST;
 548         }
 549         owner->domain = domain;
 550         owner->dev = dev;
 551         list_add_tail(&owner->list, &dev_domain_list);
 552         spin_unlock(&dev_domain_list_spinlock);
 553         return 0;
 554 }
 555 EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
 556
 557 int xen_unregister_device_domain_owner(struct pci_dev *dev)
 558 {
 559         struct xen_device_domain_owner *owner;
 560
 561         spin_lock(&dev_domain_list_spinlock);
 562         owner = find_device(dev);
 563         if (!owner) {
 564                 spin_unlock(&dev_domain_list_spinlock);
 565                 return -ENODEV;
 566         }
 567         list_del(&owner->list);
 568         spin_unlock(&dev_domain_list_spinlock);
 569         kfree(owner);
 570         return 0;
 571 }
 572 EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
 573 #endif