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 ret = irq; 180 goto free; 181 } 182 i++; 183 } 184 kfree(v); 185 return 0; 186 187 error: 188 dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n"); 189 free: 190 kfree(v); 191 return ret; 192 } 193 194 #define XEN_PIRQ_MSI_DATA (MSI_DATA_TRIGGER_EDGE | \ 195 MSI_DATA_LEVEL_ASSERT | (3 << 8) | MSI_DATA_VECTOR(0)) 196 197 static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq, 198 struct msi_msg *msg) 199 { 200 /* We set vector == 0 to tell the hypervisor we don't care about it, 201 * but we want a pirq setup instead. 202 * We use the dest_id field to pass the pirq that we want. */ 203 msg->address_hi = MSI_ADDR_BASE_HI | MSI_ADDR_EXT_DEST_ID(pirq); 204 msg->address_lo = 205 MSI_ADDR_BASE_LO | 206 MSI_ADDR_DEST_MODE_PHYSICAL | 207 MSI_ADDR_REDIRECTION_CPU | 208 MSI_ADDR_DEST_ID(pirq); 209 210 msg->data = XEN_PIRQ_MSI_DATA; 211 } 212 213 static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) 214 { 215 int irq, pirq; 216 struct msi_desc *msidesc; 217 struct msi_msg msg; 218 219 list_for_each_entry(msidesc, &dev->msi_list, list) { 220 __read_msi_msg(msidesc, &msg); 221 pirq = MSI_ADDR_EXT_DEST_ID(msg.address_hi) | 222 ((msg.address_lo >> MSI_ADDR_DEST_ID_SHIFT) & 0xff); 223 if (msg.data != XEN_PIRQ_MSI_DATA || 224 xen_irq_from_pirq(pirq) < 0) { 225 pirq = xen_allocate_pirq_msi(dev, msidesc); 226 if (pirq < 0) { 227 irq = -ENODEV; 228 goto error; 229 } 230 xen_msi_compose_msg(dev, pirq, &msg); 231 __write_msi_msg(msidesc, &msg); 232 dev_dbg(&dev->dev, "xen: msi bound to pirq=%d\n", pirq); 233 } else { 234 dev_dbg(&dev->dev, 235 "xen: msi already bound to pirq=%d\n", pirq); 236 } 237 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq, 0, 238 (type == PCI_CAP_ID_MSIX) ? 239 "msi-x" : "msi", 240 DOMID_SELF); 241 if (irq < 0) 242 goto error; 243 dev_dbg(&dev->dev, 244 "xen: msi --> pirq=%d --> irq=%d\n", pirq, irq); 245 } 246 return 0; 247 248 error: 249 dev_err(&dev->dev, 250 "Xen PCI frontend has not registered MSI/MSI-X support!\n"); 251 return irq; 252 } 253 254 #ifdef CONFIG_XEN_DOM0 255 static bool __read_mostly pci_seg_supported = true; 256 257 static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) 258 { 259 int ret = 0; 260 struct msi_desc *msidesc; 261 262 list_for_each_entry(msidesc, &dev->msi_list, list) { 263 struct physdev_map_pirq map_irq; 264 domid_t domid; 265 266 domid = ret = xen_find_device_domain_owner(dev); 267 /* N.B. Casting int's -ENODEV to uint16_t results in 0xFFED, 268 * hence check ret value for < 0. */ 269 if (ret < 0) 270 domid = DOMID_SELF; 271 272 memset(&map_irq, 0, sizeof(map_irq)); 273 map_irq.domid = domid; 274 map_irq.type = MAP_PIRQ_TYPE_MSI_SEG; 275 map_irq.index = -1; 276 map_irq.pirq = -1; 277 map_irq.bus = dev->bus->number | 278 (pci_domain_nr(dev->bus) << 16); 279 map_irq.devfn = dev->devfn; 280 281 if (type == PCI_CAP_ID_MSIX) { 282 int pos; 283 u32 table_offset, bir; 284 285 pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); 286 287 pci_read_config_dword(dev, pos + PCI_MSIX_TABLE, 288 &table_offset); 289 bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK); 290 291 map_irq.table_base = pci_resource_start(dev, bir); 292 map_irq.entry_nr = msidesc->msi_attrib.entry_nr; 293 } 294 295 ret = -EINVAL; 296 if (pci_seg_supported) 297 ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, 298 &map_irq); 299 if (ret == -EINVAL && !pci_domain_nr(dev->bus)) { 300 map_irq.type = MAP_PIRQ_TYPE_MSI; 301 map_irq.index = -1; 302 map_irq.pirq = -1; 303 map_irq.bus = dev->bus->number; 304 ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, 305 &map_irq); 306 if (ret != -EINVAL) 307 pci_seg_supported = false; 308 } 309 if (ret) { 310 dev_warn(&dev->dev, "xen map irq failed %d for %d domain\n", 311 ret, domid); 312 goto out; 313 } 314 315 ret = xen_bind_pirq_msi_to_irq(dev, msidesc, 316 map_irq.pirq, map_irq.index, 317 (type == PCI_CAP_ID_MSIX) ? 318 "msi-x" : "msi", 319 domid); 320 if (ret < 0) 321 goto out; 322 } 323 ret = 0; 324 out: 325 return ret; 326 } 327 328 static void xen_initdom_restore_msi_irqs(struct pci_dev *dev, int irq) 329 { 330 int ret = 0; 331 332 if (pci_seg_supported) { 333 struct physdev_pci_device restore_ext; 334 335 restore_ext.seg = pci_domain_nr(dev->bus); 336 restore_ext.bus = dev->bus->number; 337 restore_ext.devfn = dev->devfn; 338 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi_ext, 339 &restore_ext); 340 if (ret == -ENOSYS) 341 pci_seg_supported = false; 342 WARN(ret && ret != -ENOSYS, "restore_msi_ext -> %d\n", ret); 343 } 344 if (!pci_seg_supported) { 345 struct physdev_restore_msi restore; 346 347 restore.bus = dev->bus->number; 348 restore.devfn = dev->devfn; 349 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi, &restore); 350 WARN(ret && ret != -ENOSYS, "restore_msi -> %d\n", ret); 351 } 352 } 353 #endif 354 355 static void xen_teardown_msi_irqs(struct pci_dev *dev) 356 { 357 struct msi_desc *msidesc; 358 359 msidesc = list_entry(dev->msi_list.next, struct msi_desc, list); 360 if (msidesc->msi_attrib.is_msix) 361 xen_pci_frontend_disable_msix(dev); 362 else 363 xen_pci_frontend_disable_msi(dev); 364 365 /* Free the IRQ's and the msidesc using the generic code. */ 366 default_teardown_msi_irqs(dev); 367 } 368 369 static void xen_teardown_msi_irq(unsigned int irq) 370 { 371 xen_destroy_irq(irq); 372 } 373 374 #endif 375 376 int __init pci_xen_init(void) 377 { 378 if (!xen_pv_domain() || xen_initial_domain()) 379 return -ENODEV; 380 381 printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n"); 382 383 pcibios_set_cache_line_size(); 384 385 pcibios_enable_irq = xen_pcifront_enable_irq; 386 pcibios_disable_irq = NULL; 387 388 #ifdef CONFIG_ACPI 389 /* Keep ACPI out of the picture */ 390 acpi_noirq = 1; 391 #endif 392 393 #ifdef CONFIG_PCI_MSI 394 x86_msi.setup_msi_irqs = xen_setup_msi_irqs; 395 x86_msi.teardown_msi_irq = xen_teardown_msi_irq; 396 x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs; 397 #endif 398 return 0; 399 } 400 401 int __init pci_xen_hvm_init(void) 402 { 403 if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs)) 404 return 0; 405 406 #ifdef CONFIG_ACPI 407 /* 408 * We don't want to change the actual ACPI delivery model, 409 * just how GSIs get registered. 410 */ 411 __acpi_register_gsi = acpi_register_gsi_xen_hvm; 412 #endif 413 414 #ifdef CONFIG_PCI_MSI 415 x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs; 416 x86_msi.teardown_msi_irq = xen_teardown_msi_irq; 417 #endif 418 return 0; 419 } 420 421 #ifdef CONFIG_XEN_DOM0 422 static __init void xen_setup_acpi_sci(void) 423 { 424 int rc; 425 int trigger, polarity; 426 int gsi = acpi_sci_override_gsi; 427 int irq = -1; 428 int gsi_override = -1; 429 430 if (!gsi) 431 return; 432 433 rc = acpi_get_override_irq(gsi, &trigger, &polarity); 434 if (rc) { 435 printk(KERN_WARNING "xen: acpi_get_override_irq failed for acpi" 436 " sci, rc=%d\n", rc); 437 return; 438 } 439 trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE; 440 polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH; 441 442 printk(KERN_INFO "xen: sci override: global_irq=%d trigger=%d " 443 "polarity=%d\n", gsi, trigger, polarity); 444 445 /* Before we bind the GSI to a Linux IRQ, check whether 446 * we need to override it with bus_irq (IRQ) value. Usually for 447 * IRQs below IRQ_LEGACY_IRQ this holds IRQ == GSI, as so: 448 * ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level) 449 * but there are oddballs where the IRQ != GSI: 450 * ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level) 451 * which ends up being: gsi_to_irq[9] == 20 452 * (which is what acpi_gsi_to_irq ends up calling when starting the 453 * the ACPI interpreter and keels over since IRQ 9 has not been 454 * setup as we had setup IRQ 20 for it). 455 */ 456 if (acpi_gsi_to_irq(gsi, &irq) == 0) { 457 /* Use the provided value if it's valid. */ 458 if (irq >= 0) 459 gsi_override = irq; 460 } 461 462 gsi = xen_register_gsi(gsi, gsi_override, trigger, polarity); 463 printk(KERN_INFO "xen: acpi sci %d\n", gsi); 464 465 return; 466 } 467 468 int __init pci_xen_initial_domain(void) 469 { 470 int irq; 471 472 #ifdef CONFIG_PCI_MSI 473 x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs; 474 x86_msi.teardown_msi_irq = xen_teardown_msi_irq; 475 x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs; 476 #endif 477 xen_setup_acpi_sci(); 478 __acpi_register_gsi = acpi_register_gsi_xen; 479 /* Pre-allocate legacy irqs */ 480 for (irq = 0; irq < NR_IRQS_LEGACY; irq++) { 481 int trigger, polarity; 482 483 if (acpi_get_override_irq(irq, &trigger, &polarity) == -1) 484 continue; 485 486 xen_register_pirq(irq, -1 /* no GSI override */, 487 trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE, 488 true /* Map GSI to PIRQ */); 489 } 490 if (0 == nr_ioapics) { 491 for (irq = 0; irq < NR_IRQS_LEGACY; irq++) 492 xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic"); 493 } 494 return 0; 495 } 496 497 struct xen_device_domain_owner { 498 domid_t domain; 499 struct pci_dev *dev; 500 struct list_head list; 501 }; 502 503 static DEFINE_SPINLOCK(dev_domain_list_spinlock); 504 static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list); 505 506 static struct xen_device_domain_owner *find_device(struct pci_dev *dev) 507 { 508 struct xen_device_domain_owner *owner; 509 510 list_for_each_entry(owner, &dev_domain_list, list) { 511 if (owner->dev == dev) 512 return owner; 513 } 514 return NULL; 515 } 516 517 int xen_find_device_domain_owner(struct pci_dev *dev) 518 { 519 struct xen_device_domain_owner *owner; 520 int domain = -ENODEV; 521 522 spin_lock(&dev_domain_list_spinlock); 523 owner = find_device(dev); 524 if (owner) 525 domain = owner->domain; 526 spin_unlock(&dev_domain_list_spinlock); 527 return domain; 528 } 529 EXPORT_SYMBOL_GPL(xen_find_device_domain_owner); 530 531 int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain) 532 { 533 struct xen_device_domain_owner *owner; 534 535 owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL); 536 if (!owner) 537 return -ENODEV; 538 539 spin_lock(&dev_domain_list_spinlock); 540 if (find_device(dev)) { 541 spin_unlock(&dev_domain_list_spinlock); 542 kfree(owner); 543 return -EEXIST; 544 } 545 owner->domain = domain; 546 owner->dev = dev; 547 list_add_tail(&owner->list, &dev_domain_list); 548 spin_unlock(&dev_domain_list_spinlock); 549 return 0; 550 } 551 EXPORT_SYMBOL_GPL(xen_register_device_domain_owner); 552 553 int xen_unregister_device_domain_owner(struct pci_dev *dev) 554 { 555 struct xen_device_domain_owner *owner; 556 557 spin_lock(&dev_domain_list_spinlock); 558 owner = find_device(dev); 559 if (!owner) { 560 spin_unlock(&dev_domain_list_spinlock); 561 return -ENODEV; 562 } 563 list_del(&owner->list); 564 spin_unlock(&dev_domain_list_spinlock); 565 kfree(owner); 566 return 0; 567 } 568 EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner); 569 #endif 570