1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Xen PCI - handle PCI (INTx) and MSI infrastructure calls for PV, HVM and 4 * initial domain support. We also handle the DSDT _PRT callbacks for GSI's 5 * used in HVM and initial domain mode (PV does not parse ACPI, so it has no 6 * concept of GSIs). Under PV we hook under the pnbbios API for IRQs and 7 * 0xcf8 PCI configuration read/write. 8 * 9 * Author: Ryan Wilson <hap9@epoch.ncsc.mil> 10 * Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 11 * Stefano Stabellini <stefano.stabellini@eu.citrix.com> 12 */ 13 #include <linux/export.h> 14 #include <linux/init.h> 15 #include <linux/pci.h> 16 #include <linux/acpi.h> 17 18 #include <linux/io.h> 19 #include <asm/io_apic.h> 20 #include <asm/pci_x86.h> 21 22 #include <asm/xen/hypervisor.h> 23 24 #include <xen/features.h> 25 #include <xen/events.h> 26 #include <xen/pci.h> 27 #include <asm/xen/pci.h> 28 #include <asm/xen/cpuid.h> 29 #include <asm/apic.h> 30 #include <asm/acpi.h> 31 #include <asm/i8259.h> 32 33 static int xen_pcifront_enable_irq(struct pci_dev *dev) 34 { 35 int rc; 36 int share = 1; 37 int pirq; 38 u8 gsi; 39 40 rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi); 41 if (rc < 0) { 42 dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n", 43 rc); 44 return rc; 45 } 46 /* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/ 47 pirq = gsi; 48 49 if (gsi < nr_legacy_irqs()) 50 share = 0; 51 52 rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront"); 53 if (rc < 0) { 54 dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n", 55 gsi, pirq, rc); 56 return rc; 57 } 58 59 dev->irq = rc; 60 dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq); 61 return 0; 62 } 63 64 #ifdef CONFIG_ACPI 65 static int xen_register_pirq(u32 gsi, int triggering, bool set_pirq) 66 { 67 int rc, pirq = -1, irq; 68 struct physdev_map_pirq map_irq; 69 int shareable = 0; 70 char *name; 71 72 irq = xen_irq_from_gsi(gsi); 73 if (irq > 0) 74 return irq; 75 76 if (set_pirq) 77 pirq = gsi; 78 79 map_irq.domid = DOMID_SELF; 80 map_irq.type = MAP_PIRQ_TYPE_GSI; 81 map_irq.index = gsi; 82 map_irq.pirq = pirq; 83 84 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq); 85 if (rc) { 86 printk(KERN_WARNING "xen map irq failed %d\n", rc); 87 return -1; 88 } 89 90 if (triggering == ACPI_EDGE_SENSITIVE) { 91 shareable = 0; 92 name = "ioapic-edge"; 93 } else { 94 shareable = 1; 95 name = "ioapic-level"; 96 } 97 98 irq = xen_bind_pirq_gsi_to_irq(gsi, map_irq.pirq, shareable, name); 99 if (irq < 0) 100 goto out; 101 102 printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", map_irq.pirq, irq, gsi); 103 out: 104 return irq; 105 } 106 107 static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi, 108 int trigger, int polarity) 109 { 110 if (!xen_hvm_domain()) 111 return -1; 112 113 return xen_register_pirq(gsi, trigger, 114 false /* no mapping of GSI to PIRQ */); 115 } 116 117 #ifdef CONFIG_XEN_PV_DOM0 118 static int xen_register_gsi(u32 gsi, int triggering, int polarity) 119 { 120 int rc, irq; 121 struct physdev_setup_gsi setup_gsi; 122 123 if (!xen_pv_domain()) 124 return -1; 125 126 printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n", 127 gsi, triggering, polarity); 128 129 irq = xen_register_pirq(gsi, triggering, true); 130 131 setup_gsi.gsi = gsi; 132 setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1); 133 setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1); 134 135 rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi); 136 if (rc == -EEXIST) 137 printk(KERN_INFO "Already setup the GSI :%d\n", gsi); 138 else if (rc) { 139 printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n", 140 gsi, rc); 141 } 142 143 return irq; 144 } 145 146 static int acpi_register_gsi_xen(struct device *dev, u32 gsi, 147 int trigger, int polarity) 148 { 149 return xen_register_gsi(gsi, trigger, polarity); 150 } 151 #endif 152 #endif 153 154 #if defined(CONFIG_PCI_MSI) 155 #include <linux/msi.h> 156 157 struct xen_pci_frontend_ops *xen_pci_frontend; 158 EXPORT_SYMBOL_GPL(xen_pci_frontend); 159 160 struct xen_msi_ops { 161 int (*setup_msi_irqs)(struct pci_dev *dev, int nvec, int type); 162 void (*teardown_msi_irqs)(struct pci_dev *dev); 163 }; 164 165 static struct xen_msi_ops xen_msi_ops __ro_after_init; 166 167 static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) 168 { 169 int irq, ret, i; 170 struct msi_desc *msidesc; 171 int *v; 172 173 if (type == PCI_CAP_ID_MSI && nvec > 1) 174 return 1; 175 176 v = kcalloc(max(1, nvec), sizeof(int), GFP_KERNEL); 177 if (!v) 178 return -ENOMEM; 179 180 if (type == PCI_CAP_ID_MSIX) 181 ret = xen_pci_frontend_enable_msix(dev, v, nvec); 182 else 183 ret = xen_pci_frontend_enable_msi(dev, v); 184 if (ret) 185 goto error; 186 i = 0; 187 msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_NOTASSOCIATED) { 188 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i], 189 (type == PCI_CAP_ID_MSI) ? nvec : 1, 190 (type == PCI_CAP_ID_MSIX) ? 191 "pcifront-msi-x" : 192 "pcifront-msi", 193 DOMID_SELF); 194 if (irq < 0) { 195 ret = irq; 196 goto free; 197 } 198 i++; 199 } 200 kfree(v); 201 return msi_device_populate_sysfs(&dev->dev); 202 203 error: 204 if (ret == -ENOSYS) 205 dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n"); 206 else if (ret) 207 dev_err(&dev->dev, "Xen PCI frontend error: %d!\n", ret); 208 free: 209 kfree(v); 210 return ret; 211 } 212 213 static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq, 214 struct msi_msg *msg) 215 { 216 /* 217 * We set vector == 0 to tell the hypervisor we don't care about 218 * it, but we want a pirq setup instead. We use the dest_id fields 219 * to pass the pirq that we want. 220 */ 221 memset(msg, 0, sizeof(*msg)); 222 msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH; 223 msg->arch_addr_hi.destid_8_31 = pirq >> 8; 224 msg->arch_addr_lo.destid_0_7 = pirq & 0xFF; 225 msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW; 226 msg->arch_data.delivery_mode = APIC_DELIVERY_MODE_EXTINT; 227 } 228 229 static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) 230 { 231 int irq, pirq; 232 struct msi_desc *msidesc; 233 struct msi_msg msg; 234 235 if (type == PCI_CAP_ID_MSI && nvec > 1) 236 return 1; 237 238 msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_NOTASSOCIATED) { 239 pirq = xen_allocate_pirq_msi(dev, msidesc); 240 if (pirq < 0) { 241 irq = -ENODEV; 242 goto error; 243 } 244 xen_msi_compose_msg(dev, pirq, &msg); 245 __pci_write_msi_msg(msidesc, &msg); 246 dev_dbg(&dev->dev, "xen: msi bound to pirq=%d\n", pirq); 247 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq, 248 (type == PCI_CAP_ID_MSI) ? nvec : 1, 249 (type == PCI_CAP_ID_MSIX) ? 250 "msi-x" : "msi", 251 DOMID_SELF); 252 if (irq < 0) 253 goto error; 254 dev_dbg(&dev->dev, 255 "xen: msi --> pirq=%d --> irq=%d\n", pirq, irq); 256 } 257 return msi_device_populate_sysfs(&dev->dev); 258 259 error: 260 dev_err(&dev->dev, "Failed to create MSI%s! ret=%d!\n", 261 type == PCI_CAP_ID_MSI ? "" : "-X", irq); 262 return irq; 263 } 264 265 #ifdef CONFIG_XEN_PV_DOM0 266 static bool __read_mostly pci_seg_supported = true; 267 268 static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) 269 { 270 int ret = 0; 271 struct msi_desc *msidesc; 272 273 msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_NOTASSOCIATED) { 274 struct physdev_map_pirq map_irq; 275 domid_t domid; 276 277 domid = ret = xen_find_device_domain_owner(dev); 278 /* N.B. Casting int's -ENODEV to uint16_t results in 0xFFED, 279 * hence check ret value for < 0. */ 280 if (ret < 0) 281 domid = DOMID_SELF; 282 283 memset(&map_irq, 0, sizeof(map_irq)); 284 map_irq.domid = domid; 285 map_irq.type = MAP_PIRQ_TYPE_MSI_SEG; 286 map_irq.index = -1; 287 map_irq.pirq = -1; 288 map_irq.bus = dev->bus->number | 289 (pci_domain_nr(dev->bus) << 16); 290 map_irq.devfn = dev->devfn; 291 292 if (type == PCI_CAP_ID_MSI && nvec > 1) { 293 map_irq.type = MAP_PIRQ_TYPE_MULTI_MSI; 294 map_irq.entry_nr = nvec; 295 } else if (type == PCI_CAP_ID_MSIX) { 296 int pos; 297 unsigned long flags; 298 u32 table_offset, bir; 299 300 pos = dev->msix_cap; 301 pci_read_config_dword(dev, pos + PCI_MSIX_TABLE, 302 &table_offset); 303 bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR); 304 flags = pci_resource_flags(dev, bir); 305 if (!flags || (flags & IORESOURCE_UNSET)) 306 return -EINVAL; 307 308 map_irq.table_base = pci_resource_start(dev, bir); 309 map_irq.entry_nr = msidesc->msi_index; 310 } 311 312 ret = -EINVAL; 313 if (pci_seg_supported) 314 ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, 315 &map_irq); 316 if (type == PCI_CAP_ID_MSI && nvec > 1 && ret) { 317 /* 318 * If MAP_PIRQ_TYPE_MULTI_MSI is not available 319 * there's nothing else we can do in this case. 320 * Just set ret > 0 so driver can retry with 321 * single MSI. 322 */ 323 ret = 1; 324 goto out; 325 } 326 if (ret == -EINVAL && !pci_domain_nr(dev->bus)) { 327 map_irq.type = MAP_PIRQ_TYPE_MSI; 328 map_irq.index = -1; 329 map_irq.pirq = -1; 330 map_irq.bus = dev->bus->number; 331 ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, 332 &map_irq); 333 if (ret != -EINVAL) 334 pci_seg_supported = false; 335 } 336 if (ret) { 337 dev_warn(&dev->dev, "xen map irq failed %d for %d domain\n", 338 ret, domid); 339 goto out; 340 } 341 342 ret = xen_bind_pirq_msi_to_irq(dev, msidesc, map_irq.pirq, 343 (type == PCI_CAP_ID_MSI) ? nvec : 1, 344 (type == PCI_CAP_ID_MSIX) ? "msi-x" : "msi", 345 domid); 346 if (ret < 0) 347 goto out; 348 } 349 ret = msi_device_populate_sysfs(&dev->dev); 350 out: 351 return ret; 352 } 353 354 bool xen_initdom_restore_msi(struct pci_dev *dev) 355 { 356 int ret = 0; 357 358 if (!xen_initial_domain()) 359 return true; 360 361 if (pci_seg_supported) { 362 struct physdev_pci_device restore_ext; 363 364 restore_ext.seg = pci_domain_nr(dev->bus); 365 restore_ext.bus = dev->bus->number; 366 restore_ext.devfn = dev->devfn; 367 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi_ext, 368 &restore_ext); 369 if (ret == -ENOSYS) 370 pci_seg_supported = false; 371 WARN(ret && ret != -ENOSYS, "restore_msi_ext -> %d\n", ret); 372 } 373 if (!pci_seg_supported) { 374 struct physdev_restore_msi restore; 375 376 restore.bus = dev->bus->number; 377 restore.devfn = dev->devfn; 378 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi, &restore); 379 WARN(ret && ret != -ENOSYS, "restore_msi -> %d\n", ret); 380 } 381 return false; 382 } 383 #else /* CONFIG_XEN_PV_DOM0 */ 384 #define xen_initdom_setup_msi_irqs NULL 385 #endif /* !CONFIG_XEN_PV_DOM0 */ 386 387 static void xen_teardown_msi_irqs(struct pci_dev *dev) 388 { 389 struct msi_desc *msidesc; 390 int i; 391 392 msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_ASSOCIATED) { 393 for (i = 0; i < msidesc->nvec_used; i++) 394 xen_destroy_irq(msidesc->irq + i); 395 msidesc->irq = 0; 396 } 397 398 msi_device_destroy_sysfs(&dev->dev); 399 } 400 401 static void xen_pv_teardown_msi_irqs(struct pci_dev *dev) 402 { 403 if (dev->msix_enabled) 404 xen_pci_frontend_disable_msix(dev); 405 else 406 xen_pci_frontend_disable_msi(dev); 407 408 xen_teardown_msi_irqs(dev); 409 } 410 411 static int xen_msi_domain_alloc_irqs(struct irq_domain *domain, 412 struct device *dev, int nvec) 413 { 414 int type; 415 416 if (WARN_ON_ONCE(!dev_is_pci(dev))) 417 return -EINVAL; 418 419 type = to_pci_dev(dev)->msix_enabled ? PCI_CAP_ID_MSIX : PCI_CAP_ID_MSI; 420 421 return xen_msi_ops.setup_msi_irqs(to_pci_dev(dev), nvec, type); 422 } 423 424 static void xen_msi_domain_free_irqs(struct irq_domain *domain, 425 struct device *dev) 426 { 427 if (WARN_ON_ONCE(!dev_is_pci(dev))) 428 return; 429 430 xen_msi_ops.teardown_msi_irqs(to_pci_dev(dev)); 431 } 432 433 static struct msi_domain_ops xen_pci_msi_domain_ops = { 434 .domain_alloc_irqs = xen_msi_domain_alloc_irqs, 435 .domain_free_irqs = xen_msi_domain_free_irqs, 436 }; 437 438 static struct msi_domain_info xen_pci_msi_domain_info = { 439 .flags = MSI_FLAG_PCI_MSIX | MSI_FLAG_FREE_MSI_DESCS | MSI_FLAG_DEV_SYSFS, 440 .ops = &xen_pci_msi_domain_ops, 441 }; 442 443 /* 444 * This irq domain is a blatant violation of the irq domain design, but 445 * distangling XEN into real irq domains is not a job for mere mortals with 446 * limited XENology. But it's the least dangerous way for a mere mortal to 447 * get rid of the arch_*_msi_irqs() hackery in order to store the irq 448 * domain pointer in struct device. This irq domain wrappery allows to do 449 * that without breaking XEN terminally. 450 */ 451 static __init struct irq_domain *xen_create_pci_msi_domain(void) 452 { 453 struct irq_domain *d = NULL; 454 struct fwnode_handle *fn; 455 456 fn = irq_domain_alloc_named_fwnode("XEN-MSI"); 457 if (fn) 458 d = msi_create_irq_domain(fn, &xen_pci_msi_domain_info, NULL); 459 460 /* FIXME: No idea how to survive if this fails */ 461 BUG_ON(!d); 462 463 return d; 464 } 465 466 static __init void xen_setup_pci_msi(void) 467 { 468 if (xen_pv_domain()) { 469 if (xen_initial_domain()) 470 xen_msi_ops.setup_msi_irqs = xen_initdom_setup_msi_irqs; 471 else 472 xen_msi_ops.setup_msi_irqs = xen_setup_msi_irqs; 473 xen_msi_ops.teardown_msi_irqs = xen_pv_teardown_msi_irqs; 474 } else if (xen_hvm_domain()) { 475 xen_msi_ops.setup_msi_irqs = xen_hvm_setup_msi_irqs; 476 xen_msi_ops.teardown_msi_irqs = xen_teardown_msi_irqs; 477 } else { 478 WARN_ON_ONCE(1); 479 return; 480 } 481 482 /* 483 * Override the PCI/MSI irq domain init function. No point 484 * in allocating the native domain and never use it. 485 */ 486 x86_init.irqs.create_pci_msi_domain = xen_create_pci_msi_domain; 487 /* 488 * With XEN PIRQ/Eventchannels in use PCI/MSI[-X] masking is solely 489 * controlled by the hypervisor. 490 */ 491 pci_msi_ignore_mask = 1; 492 } 493 494 #else /* CONFIG_PCI_MSI */ 495 static inline void xen_setup_pci_msi(void) { } 496 #endif /* CONFIG_PCI_MSI */ 497 498 int __init pci_xen_init(void) 499 { 500 if (!xen_pv_domain() || xen_initial_domain()) 501 return -ENODEV; 502 503 printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n"); 504 505 pcibios_set_cache_line_size(); 506 507 pcibios_enable_irq = xen_pcifront_enable_irq; 508 pcibios_disable_irq = NULL; 509 510 /* Keep ACPI out of the picture */ 511 acpi_noirq_set(); 512 513 xen_setup_pci_msi(); 514 return 0; 515 } 516 517 #ifdef CONFIG_PCI_MSI 518 static void __init xen_hvm_msi_init(void) 519 { 520 if (!apic_is_disabled) { 521 /* 522 * If hardware supports (x2)APIC virtualization (as indicated 523 * by hypervisor's leaf 4) then we don't need to use pirqs/ 524 * event channels for MSI handling and instead use regular 525 * APIC processing 526 */ 527 uint32_t eax = cpuid_eax(xen_cpuid_base() + 4); 528 529 if (((eax & XEN_HVM_CPUID_X2APIC_VIRT) && x2apic_mode) || 530 ((eax & XEN_HVM_CPUID_APIC_ACCESS_VIRT) && boot_cpu_has(X86_FEATURE_APIC))) 531 return; 532 } 533 xen_setup_pci_msi(); 534 } 535 #endif 536 537 int __init pci_xen_hvm_init(void) 538 { 539 if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs)) 540 return 0; 541 542 #ifdef CONFIG_ACPI 543 /* 544 * We don't want to change the actual ACPI delivery model, 545 * just how GSIs get registered. 546 */ 547 __acpi_register_gsi = acpi_register_gsi_xen_hvm; 548 __acpi_unregister_gsi = NULL; 549 #endif 550 551 #ifdef CONFIG_PCI_MSI 552 /* 553 * We need to wait until after x2apic is initialized 554 * before we can set MSI IRQ ops. 555 */ 556 x86_platform.apic_post_init = xen_hvm_msi_init; 557 #endif 558 return 0; 559 } 560 561 #ifdef CONFIG_XEN_PV_DOM0 562 int __init pci_xen_initial_domain(void) 563 { 564 int irq; 565 566 xen_setup_pci_msi(); 567 __acpi_register_gsi = acpi_register_gsi_xen; 568 __acpi_unregister_gsi = NULL; 569 /* 570 * Pre-allocate the legacy IRQs. Use NR_LEGACY_IRQS here 571 * because we don't have a PIC and thus nr_legacy_irqs() is zero. 572 */ 573 for (irq = 0; irq < NR_IRQS_LEGACY; irq++) { 574 int trigger, polarity; 575 576 if (acpi_get_override_irq(irq, &trigger, &polarity) == -1) 577 continue; 578 579 xen_register_pirq(irq, 580 trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE, 581 true /* Map GSI to PIRQ */); 582 } 583 if (0 == nr_ioapics) { 584 for (irq = 0; irq < nr_legacy_irqs(); irq++) 585 xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic"); 586 } 587 return 0; 588 } 589 #endif 590 591