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