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 #include <asm/i8259.h> 27 28 static int xen_pcifront_enable_irq(struct pci_dev *dev) 29 { 30 int rc; 31 int share = 1; 32 int pirq; 33 u8 gsi; 34 35 rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi); 36 if (rc < 0) { 37 dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n", 38 rc); 39 return rc; 40 } 41 /* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/ 42 pirq = gsi; 43 44 if (gsi < nr_legacy_irqs()) 45 share = 0; 46 47 rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront"); 48 if (rc < 0) { 49 dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n", 50 gsi, pirq, rc); 51 return rc; 52 } 53 54 dev->irq = rc; 55 dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq); 56 return 0; 57 } 58 59 #ifdef CONFIG_ACPI 60 static int xen_register_pirq(u32 gsi, int gsi_override, int triggering, 61 bool set_pirq) 62 { 63 int rc, pirq = -1, irq = -1; 64 struct physdev_map_pirq map_irq; 65 int shareable = 0; 66 char *name; 67 68 irq = xen_irq_from_gsi(gsi); 69 if (irq > 0) 70 return irq; 71 72 if (set_pirq) 73 pirq = gsi; 74 75 map_irq.domid = DOMID_SELF; 76 map_irq.type = MAP_PIRQ_TYPE_GSI; 77 map_irq.index = gsi; 78 map_irq.pirq = pirq; 79 80 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq); 81 if (rc) { 82 printk(KERN_WARNING "xen map irq failed %d\n", rc); 83 return -1; 84 } 85 86 if (triggering == ACPI_EDGE_SENSITIVE) { 87 shareable = 0; 88 name = "ioapic-edge"; 89 } else { 90 shareable = 1; 91 name = "ioapic-level"; 92 } 93 94 if (gsi_override >= 0) 95 gsi = gsi_override; 96 97 irq = xen_bind_pirq_gsi_to_irq(gsi, map_irq.pirq, shareable, name); 98 if (irq < 0) 99 goto out; 100 101 printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", map_irq.pirq, irq, gsi); 102 out: 103 return irq; 104 } 105 106 static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi, 107 int trigger, int polarity) 108 { 109 if (!xen_hvm_domain()) 110 return -1; 111 112 return xen_register_pirq(gsi, -1 /* no GSI override */, trigger, 113 false /* no mapping of GSI to PIRQ */); 114 } 115 116 #ifdef CONFIG_XEN_DOM0 117 static int xen_register_gsi(u32 gsi, int gsi_override, int triggering, int polarity) 118 { 119 int rc, irq; 120 struct physdev_setup_gsi setup_gsi; 121 122 if (!xen_pv_domain()) 123 return -1; 124 125 printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n", 126 gsi, triggering, polarity); 127 128 irq = xen_register_pirq(gsi, gsi_override, triggering, true); 129 130 setup_gsi.gsi = gsi; 131 setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1); 132 setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1); 133 134 rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi); 135 if (rc == -EEXIST) 136 printk(KERN_INFO "Already setup the GSI :%d\n", gsi); 137 else if (rc) { 138 printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n", 139 gsi, rc); 140 } 141 142 return irq; 143 } 144 145 static int acpi_register_gsi_xen(struct device *dev, u32 gsi, 146 int trigger, int polarity) 147 { 148 return xen_register_gsi(gsi, -1 /* no GSI override */, trigger, polarity); 149 } 150 #endif 151 #endif 152 153 #if defined(CONFIG_PCI_MSI) 154 #include <linux/msi.h> 155 #include <asm/msidef.h> 156 157 struct xen_pci_frontend_ops *xen_pci_frontend; 158 EXPORT_SYMBOL_GPL(xen_pci_frontend); 159 160 static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) 161 { 162 int irq, ret, i; 163 struct msi_desc *msidesc; 164 int *v; 165 166 if (type == PCI_CAP_ID_MSI && nvec > 1) 167 return 1; 168 169 v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL); 170 if (!v) 171 return -ENOMEM; 172 173 if (type == PCI_CAP_ID_MSIX) 174 ret = xen_pci_frontend_enable_msix(dev, v, nvec); 175 else 176 ret = xen_pci_frontend_enable_msi(dev, v); 177 if (ret) 178 goto error; 179 i = 0; 180 list_for_each_entry(msidesc, &dev->msi_list, list) { 181 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i], 182 (type == PCI_CAP_ID_MSI) ? nvec : 1, 183 (type == PCI_CAP_ID_MSIX) ? 184 "pcifront-msi-x" : 185 "pcifront-msi", 186 DOMID_SELF); 187 if (irq < 0) { 188 ret = irq; 189 goto free; 190 } 191 i++; 192 } 193 kfree(v); 194 return 0; 195 196 error: 197 dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n"); 198 free: 199 kfree(v); 200 return ret; 201 } 202 203 #define XEN_PIRQ_MSI_DATA (MSI_DATA_TRIGGER_EDGE | \ 204 MSI_DATA_LEVEL_ASSERT | (3 << 8) | MSI_DATA_VECTOR(0)) 205 206 static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq, 207 struct msi_msg *msg) 208 { 209 /* We set vector == 0 to tell the hypervisor we don't care about it, 210 * but we want a pirq setup instead. 211 * We use the dest_id field to pass the pirq that we want. */ 212 msg->address_hi = MSI_ADDR_BASE_HI | MSI_ADDR_EXT_DEST_ID(pirq); 213 msg->address_lo = 214 MSI_ADDR_BASE_LO | 215 MSI_ADDR_DEST_MODE_PHYSICAL | 216 MSI_ADDR_REDIRECTION_CPU | 217 MSI_ADDR_DEST_ID(pirq); 218 219 msg->data = XEN_PIRQ_MSI_DATA; 220 } 221 222 static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) 223 { 224 int irq, pirq; 225 struct msi_desc *msidesc; 226 struct msi_msg msg; 227 228 if (type == PCI_CAP_ID_MSI && nvec > 1) 229 return 1; 230 231 list_for_each_entry(msidesc, &dev->msi_list, list) { 232 __read_msi_msg(msidesc, &msg); 233 pirq = MSI_ADDR_EXT_DEST_ID(msg.address_hi) | 234 ((msg.address_lo >> MSI_ADDR_DEST_ID_SHIFT) & 0xff); 235 if (msg.data != XEN_PIRQ_MSI_DATA || 236 xen_irq_from_pirq(pirq) < 0) { 237 pirq = xen_allocate_pirq_msi(dev, msidesc); 238 if (pirq < 0) { 239 irq = -ENODEV; 240 goto error; 241 } 242 xen_msi_compose_msg(dev, pirq, &msg); 243 __write_msi_msg(msidesc, &msg); 244 dev_dbg(&dev->dev, "xen: msi bound to pirq=%d\n", pirq); 245 } else { 246 dev_dbg(&dev->dev, 247 "xen: msi already bound to pirq=%d\n", pirq); 248 } 249 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq, 250 (type == PCI_CAP_ID_MSI) ? nvec : 1, 251 (type == PCI_CAP_ID_MSIX) ? 252 "msi-x" : "msi", 253 DOMID_SELF); 254 if (irq < 0) 255 goto error; 256 dev_dbg(&dev->dev, 257 "xen: msi --> pirq=%d --> irq=%d\n", pirq, irq); 258 } 259 return 0; 260 261 error: 262 dev_err(&dev->dev, 263 "Xen PCI frontend has not registered MSI/MSI-X support!\n"); 264 return irq; 265 } 266 267 #ifdef CONFIG_XEN_DOM0 268 static bool __read_mostly pci_seg_supported = true; 269 270 static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) 271 { 272 int ret = 0; 273 struct msi_desc *msidesc; 274 275 list_for_each_entry(msidesc, &dev->msi_list, list) { 276 struct physdev_map_pirq map_irq; 277 domid_t domid; 278 279 domid = ret = xen_find_device_domain_owner(dev); 280 /* N.B. Casting int's -ENODEV to uint16_t results in 0xFFED, 281 * hence check ret value for < 0. */ 282 if (ret < 0) 283 domid = DOMID_SELF; 284 285 memset(&map_irq, 0, sizeof(map_irq)); 286 map_irq.domid = domid; 287 map_irq.type = MAP_PIRQ_TYPE_MSI_SEG; 288 map_irq.index = -1; 289 map_irq.pirq = -1; 290 map_irq.bus = dev->bus->number | 291 (pci_domain_nr(dev->bus) << 16); 292 map_irq.devfn = dev->devfn; 293 294 if (type == PCI_CAP_ID_MSI && nvec > 1) { 295 map_irq.type = MAP_PIRQ_TYPE_MULTI_MSI; 296 map_irq.entry_nr = nvec; 297 } else if (type == PCI_CAP_ID_MSIX) { 298 int pos; 299 u32 table_offset, bir; 300 301 pos = dev->msix_cap; 302 pci_read_config_dword(dev, pos + PCI_MSIX_TABLE, 303 &table_offset); 304 bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR); 305 306 map_irq.table_base = pci_resource_start(dev, bir); 307 map_irq.entry_nr = msidesc->msi_attrib.entry_nr; 308 } 309 310 ret = -EINVAL; 311 if (pci_seg_supported) 312 ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, 313 &map_irq); 314 if (type == PCI_CAP_ID_MSI && nvec > 1 && ret) { 315 /* 316 * If MAP_PIRQ_TYPE_MULTI_MSI is not available 317 * there's nothing else we can do in this case. 318 * Just set ret > 0 so driver can retry with 319 * single MSI. 320 */ 321 ret = 1; 322 goto out; 323 } 324 if (ret == -EINVAL && !pci_domain_nr(dev->bus)) { 325 map_irq.type = MAP_PIRQ_TYPE_MSI; 326 map_irq.index = -1; 327 map_irq.pirq = -1; 328 map_irq.bus = dev->bus->number; 329 ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, 330 &map_irq); 331 if (ret != -EINVAL) 332 pci_seg_supported = false; 333 } 334 if (ret) { 335 dev_warn(&dev->dev, "xen map irq failed %d for %d domain\n", 336 ret, domid); 337 goto out; 338 } 339 340 ret = xen_bind_pirq_msi_to_irq(dev, msidesc, map_irq.pirq, 341 (type == PCI_CAP_ID_MSI) ? nvec : 1, 342 (type == PCI_CAP_ID_MSIX) ? "msi-x" : "msi", 343 domid); 344 if (ret < 0) 345 goto out; 346 } 347 ret = 0; 348 out: 349 return ret; 350 } 351 352 static void xen_initdom_restore_msi_irqs(struct pci_dev *dev) 353 { 354 int ret = 0; 355 356 if (pci_seg_supported) { 357 struct physdev_pci_device restore_ext; 358 359 restore_ext.seg = pci_domain_nr(dev->bus); 360 restore_ext.bus = dev->bus->number; 361 restore_ext.devfn = dev->devfn; 362 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi_ext, 363 &restore_ext); 364 if (ret == -ENOSYS) 365 pci_seg_supported = false; 366 WARN(ret && ret != -ENOSYS, "restore_msi_ext -> %d\n", ret); 367 } 368 if (!pci_seg_supported) { 369 struct physdev_restore_msi restore; 370 371 restore.bus = dev->bus->number; 372 restore.devfn = dev->devfn; 373 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi, &restore); 374 WARN(ret && ret != -ENOSYS, "restore_msi -> %d\n", ret); 375 } 376 } 377 #endif 378 379 static void xen_teardown_msi_irqs(struct pci_dev *dev) 380 { 381 struct msi_desc *msidesc; 382 383 msidesc = list_entry(dev->msi_list.next, struct msi_desc, list); 384 if (msidesc->msi_attrib.is_msix) 385 xen_pci_frontend_disable_msix(dev); 386 else 387 xen_pci_frontend_disable_msi(dev); 388 389 /* Free the IRQ's and the msidesc using the generic code. */ 390 default_teardown_msi_irqs(dev); 391 } 392 393 static void xen_teardown_msi_irq(unsigned int irq) 394 { 395 xen_destroy_irq(irq); 396 } 397 static u32 xen_nop_msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag) 398 { 399 return 0; 400 } 401 static u32 xen_nop_msix_mask_irq(struct msi_desc *desc, u32 flag) 402 { 403 return 0; 404 } 405 #endif 406 407 int __init pci_xen_init(void) 408 { 409 if (!xen_pv_domain() || xen_initial_domain()) 410 return -ENODEV; 411 412 printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n"); 413 414 pcibios_set_cache_line_size(); 415 416 pcibios_enable_irq = xen_pcifront_enable_irq; 417 pcibios_disable_irq = NULL; 418 419 #ifdef CONFIG_ACPI 420 /* Keep ACPI out of the picture */ 421 acpi_noirq = 1; 422 #endif 423 424 #ifdef CONFIG_PCI_MSI 425 x86_msi.setup_msi_irqs = xen_setup_msi_irqs; 426 x86_msi.teardown_msi_irq = xen_teardown_msi_irq; 427 x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs; 428 x86_msi.msi_mask_irq = xen_nop_msi_mask_irq; 429 x86_msi.msix_mask_irq = xen_nop_msix_mask_irq; 430 #endif 431 return 0; 432 } 433 434 int __init pci_xen_hvm_init(void) 435 { 436 if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs)) 437 return 0; 438 439 #ifdef CONFIG_ACPI 440 /* 441 * We don't want to change the actual ACPI delivery model, 442 * just how GSIs get registered. 443 */ 444 __acpi_register_gsi = acpi_register_gsi_xen_hvm; 445 #endif 446 447 #ifdef CONFIG_PCI_MSI 448 x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs; 449 x86_msi.teardown_msi_irq = xen_teardown_msi_irq; 450 #endif 451 return 0; 452 } 453 454 #ifdef CONFIG_XEN_DOM0 455 static __init void xen_setup_acpi_sci(void) 456 { 457 int rc; 458 int trigger, polarity; 459 int gsi = acpi_sci_override_gsi; 460 int irq = -1; 461 int gsi_override = -1; 462 463 if (!gsi) 464 return; 465 466 rc = acpi_get_override_irq(gsi, &trigger, &polarity); 467 if (rc) { 468 printk(KERN_WARNING "xen: acpi_get_override_irq failed for acpi" 469 " sci, rc=%d\n", rc); 470 return; 471 } 472 trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE; 473 polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH; 474 475 printk(KERN_INFO "xen: sci override: global_irq=%d trigger=%d " 476 "polarity=%d\n", gsi, trigger, polarity); 477 478 /* Before we bind the GSI to a Linux IRQ, check whether 479 * we need to override it with bus_irq (IRQ) value. Usually for 480 * IRQs below IRQ_LEGACY_IRQ this holds IRQ == GSI, as so: 481 * ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level) 482 * but there are oddballs where the IRQ != GSI: 483 * ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level) 484 * which ends up being: gsi_to_irq[9] == 20 485 * (which is what acpi_gsi_to_irq ends up calling when starting the 486 * the ACPI interpreter and keels over since IRQ 9 has not been 487 * setup as we had setup IRQ 20 for it). 488 */ 489 if (acpi_gsi_to_irq(gsi, &irq) == 0) { 490 /* Use the provided value if it's valid. */ 491 if (irq >= 0) 492 gsi_override = irq; 493 } 494 495 gsi = xen_register_gsi(gsi, gsi_override, trigger, polarity); 496 printk(KERN_INFO "xen: acpi sci %d\n", gsi); 497 498 return; 499 } 500 501 int __init pci_xen_initial_domain(void) 502 { 503 int irq; 504 505 #ifdef CONFIG_PCI_MSI 506 x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs; 507 x86_msi.teardown_msi_irq = xen_teardown_msi_irq; 508 x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs; 509 x86_msi.msi_mask_irq = xen_nop_msi_mask_irq; 510 x86_msi.msix_mask_irq = xen_nop_msix_mask_irq; 511 #endif 512 xen_setup_acpi_sci(); 513 __acpi_register_gsi = acpi_register_gsi_xen; 514 /* Pre-allocate legacy irqs */ 515 for (irq = 0; irq < nr_legacy_irqs(); irq++) { 516 int trigger, polarity; 517 518 if (acpi_get_override_irq(irq, &trigger, &polarity) == -1) 519 continue; 520 521 xen_register_pirq(irq, -1 /* no GSI override */, 522 trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE, 523 true /* Map GSI to PIRQ */); 524 } 525 if (0 == nr_ioapics) { 526 for (irq = 0; irq < nr_legacy_irqs(); irq++) 527 xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic"); 528 } 529 return 0; 530 } 531 532 struct xen_device_domain_owner { 533 domid_t domain; 534 struct pci_dev *dev; 535 struct list_head list; 536 }; 537 538 static DEFINE_SPINLOCK(dev_domain_list_spinlock); 539 static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list); 540 541 static struct xen_device_domain_owner *find_device(struct pci_dev *dev) 542 { 543 struct xen_device_domain_owner *owner; 544 545 list_for_each_entry(owner, &dev_domain_list, list) { 546 if (owner->dev == dev) 547 return owner; 548 } 549 return NULL; 550 } 551 552 int xen_find_device_domain_owner(struct pci_dev *dev) 553 { 554 struct xen_device_domain_owner *owner; 555 int domain = -ENODEV; 556 557 spin_lock(&dev_domain_list_spinlock); 558 owner = find_device(dev); 559 if (owner) 560 domain = owner->domain; 561 spin_unlock(&dev_domain_list_spinlock); 562 return domain; 563 } 564 EXPORT_SYMBOL_GPL(xen_find_device_domain_owner); 565 566 int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain) 567 { 568 struct xen_device_domain_owner *owner; 569 570 owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL); 571 if (!owner) 572 return -ENODEV; 573 574 spin_lock(&dev_domain_list_spinlock); 575 if (find_device(dev)) { 576 spin_unlock(&dev_domain_list_spinlock); 577 kfree(owner); 578 return -EEXIST; 579 } 580 owner->domain = domain; 581 owner->dev = dev; 582 list_add_tail(&owner->list, &dev_domain_list); 583 spin_unlock(&dev_domain_list_spinlock); 584 return 0; 585 } 586 EXPORT_SYMBOL_GPL(xen_register_device_domain_owner); 587 588 int xen_unregister_device_domain_owner(struct pci_dev *dev) 589 { 590 struct xen_device_domain_owner *owner; 591 592 spin_lock(&dev_domain_list_spinlock); 593 owner = find_device(dev); 594 if (!owner) { 595 spin_unlock(&dev_domain_list_spinlock); 596 return -ENODEV; 597 } 598 list_del(&owner->list); 599 spin_unlock(&dev_domain_list_spinlock); 600 kfree(owner); 601 return 0; 602 } 603 EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner); 604 #endif 605