1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Xen PCI Frontend 4 * 5 * Author: Ryan Wilson <hap9@epoch.ncsc.mil> 6 */ 7 #include <linux/module.h> 8 #include <linux/init.h> 9 #include <linux/mm.h> 10 #include <xen/xenbus.h> 11 #include <xen/events.h> 12 #include <xen/grant_table.h> 13 #include <xen/page.h> 14 #include <linux/spinlock.h> 15 #include <linux/pci.h> 16 #include <linux/msi.h> 17 #include <xen/interface/io/pciif.h> 18 #include <asm/xen/pci.h> 19 #include <linux/interrupt.h> 20 #include <linux/atomic.h> 21 #include <linux/workqueue.h> 22 #include <linux/bitops.h> 23 #include <linux/time.h> 24 #include <linux/ktime.h> 25 #include <xen/platform_pci.h> 26 27 #include <asm/xen/swiotlb-xen.h> 28 #define INVALID_GRANT_REF (0) 29 #define INVALID_EVTCHN (-1) 30 31 struct pci_bus_entry { 32 struct list_head list; 33 struct pci_bus *bus; 34 }; 35 36 #define _PDEVB_op_active (0) 37 #define PDEVB_op_active (1 << (_PDEVB_op_active)) 38 39 struct pcifront_device { 40 struct xenbus_device *xdev; 41 struct list_head root_buses; 42 43 int evtchn; 44 int gnt_ref; 45 46 int irq; 47 48 /* Lock this when doing any operations in sh_info */ 49 spinlock_t sh_info_lock; 50 struct xen_pci_sharedinfo *sh_info; 51 struct work_struct op_work; 52 unsigned long flags; 53 54 }; 55 56 struct pcifront_sd { 57 struct pci_sysdata sd; 58 struct pcifront_device *pdev; 59 }; 60 61 static inline struct pcifront_device * 62 pcifront_get_pdev(struct pcifront_sd *sd) 63 { 64 return sd->pdev; 65 } 66 67 static inline void pcifront_init_sd(struct pcifront_sd *sd, 68 unsigned int domain, unsigned int bus, 69 struct pcifront_device *pdev) 70 { 71 /* Because we do not expose that information via XenBus. */ 72 sd->sd.node = first_online_node; 73 sd->sd.domain = domain; 74 sd->pdev = pdev; 75 } 76 77 static DEFINE_SPINLOCK(pcifront_dev_lock); 78 static struct pcifront_device *pcifront_dev; 79 80 static int errno_to_pcibios_err(int errno) 81 { 82 switch (errno) { 83 case XEN_PCI_ERR_success: 84 return PCIBIOS_SUCCESSFUL; 85 86 case XEN_PCI_ERR_dev_not_found: 87 return PCIBIOS_DEVICE_NOT_FOUND; 88 89 case XEN_PCI_ERR_invalid_offset: 90 case XEN_PCI_ERR_op_failed: 91 return PCIBIOS_BAD_REGISTER_NUMBER; 92 93 case XEN_PCI_ERR_not_implemented: 94 return PCIBIOS_FUNC_NOT_SUPPORTED; 95 96 case XEN_PCI_ERR_access_denied: 97 return PCIBIOS_SET_FAILED; 98 } 99 return errno; 100 } 101 102 static inline void schedule_pcifront_aer_op(struct pcifront_device *pdev) 103 { 104 if (test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags) 105 && !test_and_set_bit(_PDEVB_op_active, &pdev->flags)) { 106 dev_dbg(&pdev->xdev->dev, "schedule aer frontend job\n"); 107 schedule_work(&pdev->op_work); 108 } 109 } 110 111 static int do_pci_op(struct pcifront_device *pdev, struct xen_pci_op *op) 112 { 113 int err = 0; 114 struct xen_pci_op *active_op = &pdev->sh_info->op; 115 unsigned long irq_flags; 116 evtchn_port_t port = pdev->evtchn; 117 unsigned irq = pdev->irq; 118 s64 ns, ns_timeout; 119 120 spin_lock_irqsave(&pdev->sh_info_lock, irq_flags); 121 122 memcpy(active_op, op, sizeof(struct xen_pci_op)); 123 124 /* Go */ 125 wmb(); 126 set_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags); 127 notify_remote_via_evtchn(port); 128 129 /* 130 * We set a poll timeout of 3 seconds but give up on return after 131 * 2 seconds. It is better to time out too late rather than too early 132 * (in the latter case we end up continually re-executing poll() with a 133 * timeout in the past). 1s difference gives plenty of slack for error. 134 */ 135 ns_timeout = ktime_get_ns() + 2 * (s64)NSEC_PER_SEC; 136 137 xen_clear_irq_pending(irq); 138 139 while (test_bit(_XEN_PCIF_active, 140 (unsigned long *)&pdev->sh_info->flags)) { 141 xen_poll_irq_timeout(irq, jiffies + 3*HZ); 142 xen_clear_irq_pending(irq); 143 ns = ktime_get_ns(); 144 if (ns > ns_timeout) { 145 dev_err(&pdev->xdev->dev, 146 "pciback not responding!!!\n"); 147 clear_bit(_XEN_PCIF_active, 148 (unsigned long *)&pdev->sh_info->flags); 149 err = XEN_PCI_ERR_dev_not_found; 150 goto out; 151 } 152 } 153 154 /* 155 * We might lose backend service request since we 156 * reuse same evtchn with pci_conf backend response. So re-schedule 157 * aer pcifront service. 158 */ 159 if (test_bit(_XEN_PCIB_active, 160 (unsigned long *)&pdev->sh_info->flags)) { 161 dev_err(&pdev->xdev->dev, 162 "schedule aer pcifront service\n"); 163 schedule_pcifront_aer_op(pdev); 164 } 165 166 memcpy(op, active_op, sizeof(struct xen_pci_op)); 167 168 err = op->err; 169 out: 170 spin_unlock_irqrestore(&pdev->sh_info_lock, irq_flags); 171 return err; 172 } 173 174 /* Access to this function is spinlocked in drivers/pci/access.c */ 175 static int pcifront_bus_read(struct pci_bus *bus, unsigned int devfn, 176 int where, int size, u32 *val) 177 { 178 int err = 0; 179 struct xen_pci_op op = { 180 .cmd = XEN_PCI_OP_conf_read, 181 .domain = pci_domain_nr(bus), 182 .bus = bus->number, 183 .devfn = devfn, 184 .offset = where, 185 .size = size, 186 }; 187 struct pcifront_sd *sd = bus->sysdata; 188 struct pcifront_device *pdev = pcifront_get_pdev(sd); 189 190 dev_dbg(&pdev->xdev->dev, 191 "read dev=%04x:%02x:%02x.%d - offset %x size %d\n", 192 pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), 193 PCI_FUNC(devfn), where, size); 194 195 err = do_pci_op(pdev, &op); 196 197 if (likely(!err)) { 198 dev_dbg(&pdev->xdev->dev, "read got back value %x\n", 199 op.value); 200 201 *val = op.value; 202 } else if (err == -ENODEV) { 203 /* No device here, pretend that it just returned 0 */ 204 err = 0; 205 *val = 0; 206 } 207 208 return errno_to_pcibios_err(err); 209 } 210 211 /* Access to this function is spinlocked in drivers/pci/access.c */ 212 static int pcifront_bus_write(struct pci_bus *bus, unsigned int devfn, 213 int where, int size, u32 val) 214 { 215 struct xen_pci_op op = { 216 .cmd = XEN_PCI_OP_conf_write, 217 .domain = pci_domain_nr(bus), 218 .bus = bus->number, 219 .devfn = devfn, 220 .offset = where, 221 .size = size, 222 .value = val, 223 }; 224 struct pcifront_sd *sd = bus->sysdata; 225 struct pcifront_device *pdev = pcifront_get_pdev(sd); 226 227 dev_dbg(&pdev->xdev->dev, 228 "write dev=%04x:%02x:%02x.%d - offset %x size %d val %x\n", 229 pci_domain_nr(bus), bus->number, 230 PCI_SLOT(devfn), PCI_FUNC(devfn), where, size, val); 231 232 return errno_to_pcibios_err(do_pci_op(pdev, &op)); 233 } 234 235 static struct pci_ops pcifront_bus_ops = { 236 .read = pcifront_bus_read, 237 .write = pcifront_bus_write, 238 }; 239 240 #ifdef CONFIG_PCI_MSI 241 static int pci_frontend_enable_msix(struct pci_dev *dev, 242 int vector[], int nvec) 243 { 244 int err; 245 int i; 246 struct xen_pci_op op = { 247 .cmd = XEN_PCI_OP_enable_msix, 248 .domain = pci_domain_nr(dev->bus), 249 .bus = dev->bus->number, 250 .devfn = dev->devfn, 251 .value = nvec, 252 }; 253 struct pcifront_sd *sd = dev->bus->sysdata; 254 struct pcifront_device *pdev = pcifront_get_pdev(sd); 255 struct msi_desc *entry; 256 257 if (nvec > SH_INFO_MAX_VEC) { 258 pci_err(dev, "too many vectors (0x%x) for PCI frontend:" 259 " Increase SH_INFO_MAX_VEC\n", nvec); 260 return -EINVAL; 261 } 262 263 i = 0; 264 for_each_pci_msi_entry(entry, dev) { 265 op.msix_entries[i].entry = entry->msi_attrib.entry_nr; 266 /* Vector is useless at this point. */ 267 op.msix_entries[i].vector = -1; 268 i++; 269 } 270 271 err = do_pci_op(pdev, &op); 272 273 if (likely(!err)) { 274 if (likely(!op.value)) { 275 /* we get the result */ 276 for (i = 0; i < nvec; i++) { 277 if (op.msix_entries[i].vector <= 0) { 278 pci_warn(dev, "MSI-X entry %d is invalid: %d!\n", 279 i, op.msix_entries[i].vector); 280 err = -EINVAL; 281 vector[i] = -1; 282 continue; 283 } 284 vector[i] = op.msix_entries[i].vector; 285 } 286 } else { 287 pr_info("enable msix get value %x\n", op.value); 288 err = op.value; 289 } 290 } else { 291 pci_err(dev, "enable msix get err %x\n", err); 292 } 293 return err; 294 } 295 296 static void pci_frontend_disable_msix(struct pci_dev *dev) 297 { 298 int err; 299 struct xen_pci_op op = { 300 .cmd = XEN_PCI_OP_disable_msix, 301 .domain = pci_domain_nr(dev->bus), 302 .bus = dev->bus->number, 303 .devfn = dev->devfn, 304 }; 305 struct pcifront_sd *sd = dev->bus->sysdata; 306 struct pcifront_device *pdev = pcifront_get_pdev(sd); 307 308 err = do_pci_op(pdev, &op); 309 310 /* What should do for error ? */ 311 if (err) 312 pci_err(dev, "pci_disable_msix get err %x\n", err); 313 } 314 315 static int pci_frontend_enable_msi(struct pci_dev *dev, int vector[]) 316 { 317 int err; 318 struct xen_pci_op op = { 319 .cmd = XEN_PCI_OP_enable_msi, 320 .domain = pci_domain_nr(dev->bus), 321 .bus = dev->bus->number, 322 .devfn = dev->devfn, 323 }; 324 struct pcifront_sd *sd = dev->bus->sysdata; 325 struct pcifront_device *pdev = pcifront_get_pdev(sd); 326 327 err = do_pci_op(pdev, &op); 328 if (likely(!err)) { 329 vector[0] = op.value; 330 if (op.value <= 0) { 331 pci_warn(dev, "MSI entry is invalid: %d!\n", 332 op.value); 333 err = -EINVAL; 334 vector[0] = -1; 335 } 336 } else { 337 pci_err(dev, "pci frontend enable msi failed for dev " 338 "%x:%x\n", op.bus, op.devfn); 339 err = -EINVAL; 340 } 341 return err; 342 } 343 344 static void pci_frontend_disable_msi(struct pci_dev *dev) 345 { 346 int err; 347 struct xen_pci_op op = { 348 .cmd = XEN_PCI_OP_disable_msi, 349 .domain = pci_domain_nr(dev->bus), 350 .bus = dev->bus->number, 351 .devfn = dev->devfn, 352 }; 353 struct pcifront_sd *sd = dev->bus->sysdata; 354 struct pcifront_device *pdev = pcifront_get_pdev(sd); 355 356 err = do_pci_op(pdev, &op); 357 if (err == XEN_PCI_ERR_dev_not_found) { 358 /* XXX No response from backend, what shall we do? */ 359 pr_info("get no response from backend for disable MSI\n"); 360 return; 361 } 362 if (err) 363 /* how can pciback notify us fail? */ 364 pr_info("get fake response from backend\n"); 365 } 366 367 static struct xen_pci_frontend_ops pci_frontend_ops = { 368 .enable_msi = pci_frontend_enable_msi, 369 .disable_msi = pci_frontend_disable_msi, 370 .enable_msix = pci_frontend_enable_msix, 371 .disable_msix = pci_frontend_disable_msix, 372 }; 373 374 static void pci_frontend_registrar(int enable) 375 { 376 if (enable) 377 xen_pci_frontend = &pci_frontend_ops; 378 else 379 xen_pci_frontend = NULL; 380 }; 381 #else 382 static inline void pci_frontend_registrar(int enable) { }; 383 #endif /* CONFIG_PCI_MSI */ 384 385 /* Claim resources for the PCI frontend as-is, backend won't allow changes */ 386 static int pcifront_claim_resource(struct pci_dev *dev, void *data) 387 { 388 struct pcifront_device *pdev = data; 389 int i; 390 struct resource *r; 391 392 for (i = 0; i < PCI_NUM_RESOURCES; i++) { 393 r = &dev->resource[i]; 394 395 if (!r->parent && r->start && r->flags) { 396 dev_info(&pdev->xdev->dev, "claiming resource %s/%d\n", 397 pci_name(dev), i); 398 if (pci_claim_resource(dev, i)) { 399 dev_err(&pdev->xdev->dev, "Could not claim resource %s/%d! " 400 "Device offline. Try using e820_host=1 in the guest config.\n", 401 pci_name(dev), i); 402 } 403 } 404 } 405 406 return 0; 407 } 408 409 static int pcifront_scan_bus(struct pcifront_device *pdev, 410 unsigned int domain, unsigned int bus, 411 struct pci_bus *b) 412 { 413 struct pci_dev *d; 414 unsigned int devfn; 415 416 /* Scan the bus for functions and add. 417 * We omit handling of PCI bridge attachment because pciback prevents 418 * bridges from being exported. 419 */ 420 for (devfn = 0; devfn < 0x100; devfn++) { 421 d = pci_get_slot(b, devfn); 422 if (d) { 423 /* Device is already known. */ 424 pci_dev_put(d); 425 continue; 426 } 427 428 d = pci_scan_single_device(b, devfn); 429 if (d) 430 dev_info(&pdev->xdev->dev, "New device on " 431 "%04x:%02x:%02x.%d found.\n", domain, bus, 432 PCI_SLOT(devfn), PCI_FUNC(devfn)); 433 } 434 435 return 0; 436 } 437 438 static int pcifront_scan_root(struct pcifront_device *pdev, 439 unsigned int domain, unsigned int bus) 440 { 441 struct pci_bus *b; 442 LIST_HEAD(resources); 443 struct pcifront_sd *sd = NULL; 444 struct pci_bus_entry *bus_entry = NULL; 445 int err = 0; 446 static struct resource busn_res = { 447 .start = 0, 448 .end = 255, 449 .flags = IORESOURCE_BUS, 450 }; 451 452 #ifndef CONFIG_PCI_DOMAINS 453 if (domain != 0) { 454 dev_err(&pdev->xdev->dev, 455 "PCI Root in non-zero PCI Domain! domain=%d\n", domain); 456 dev_err(&pdev->xdev->dev, 457 "Please compile with CONFIG_PCI_DOMAINS\n"); 458 err = -EINVAL; 459 goto err_out; 460 } 461 #endif 462 463 dev_info(&pdev->xdev->dev, "Creating PCI Frontend Bus %04x:%02x\n", 464 domain, bus); 465 466 bus_entry = kzalloc(sizeof(*bus_entry), GFP_KERNEL); 467 sd = kzalloc(sizeof(*sd), GFP_KERNEL); 468 if (!bus_entry || !sd) { 469 err = -ENOMEM; 470 goto err_out; 471 } 472 pci_add_resource(&resources, &ioport_resource); 473 pci_add_resource(&resources, &iomem_resource); 474 pci_add_resource(&resources, &busn_res); 475 pcifront_init_sd(sd, domain, bus, pdev); 476 477 pci_lock_rescan_remove(); 478 479 b = pci_scan_root_bus(&pdev->xdev->dev, bus, 480 &pcifront_bus_ops, sd, &resources); 481 if (!b) { 482 dev_err(&pdev->xdev->dev, 483 "Error creating PCI Frontend Bus!\n"); 484 err = -ENOMEM; 485 pci_unlock_rescan_remove(); 486 pci_free_resource_list(&resources); 487 goto err_out; 488 } 489 490 bus_entry->bus = b; 491 492 list_add(&bus_entry->list, &pdev->root_buses); 493 494 /* pci_scan_root_bus skips devices which do not have a 495 * devfn==0. The pcifront_scan_bus enumerates all devfn. */ 496 err = pcifront_scan_bus(pdev, domain, bus, b); 497 498 /* Claim resources before going "live" with our devices */ 499 pci_walk_bus(b, pcifront_claim_resource, pdev); 500 501 /* Create SysFS and notify udev of the devices. Aka: "going live" */ 502 pci_bus_add_devices(b); 503 504 pci_unlock_rescan_remove(); 505 return err; 506 507 err_out: 508 kfree(bus_entry); 509 kfree(sd); 510 511 return err; 512 } 513 514 static int pcifront_rescan_root(struct pcifront_device *pdev, 515 unsigned int domain, unsigned int bus) 516 { 517 int err; 518 struct pci_bus *b; 519 520 #ifndef CONFIG_PCI_DOMAINS 521 if (domain != 0) { 522 dev_err(&pdev->xdev->dev, 523 "PCI Root in non-zero PCI Domain! domain=%d\n", domain); 524 dev_err(&pdev->xdev->dev, 525 "Please compile with CONFIG_PCI_DOMAINS\n"); 526 return -EINVAL; 527 } 528 #endif 529 530 dev_info(&pdev->xdev->dev, "Rescanning PCI Frontend Bus %04x:%02x\n", 531 domain, bus); 532 533 b = pci_find_bus(domain, bus); 534 if (!b) 535 /* If the bus is unknown, create it. */ 536 return pcifront_scan_root(pdev, domain, bus); 537 538 err = pcifront_scan_bus(pdev, domain, bus, b); 539 540 /* Claim resources before going "live" with our devices */ 541 pci_walk_bus(b, pcifront_claim_resource, pdev); 542 543 /* Create SysFS and notify udev of the devices. Aka: "going live" */ 544 pci_bus_add_devices(b); 545 546 return err; 547 } 548 549 static void free_root_bus_devs(struct pci_bus *bus) 550 { 551 struct pci_dev *dev; 552 553 while (!list_empty(&bus->devices)) { 554 dev = container_of(bus->devices.next, struct pci_dev, 555 bus_list); 556 pci_dbg(dev, "removing device\n"); 557 pci_stop_and_remove_bus_device(dev); 558 } 559 } 560 561 static void pcifront_free_roots(struct pcifront_device *pdev) 562 { 563 struct pci_bus_entry *bus_entry, *t; 564 565 dev_dbg(&pdev->xdev->dev, "cleaning up root buses\n"); 566 567 pci_lock_rescan_remove(); 568 list_for_each_entry_safe(bus_entry, t, &pdev->root_buses, list) { 569 list_del(&bus_entry->list); 570 571 free_root_bus_devs(bus_entry->bus); 572 573 kfree(bus_entry->bus->sysdata); 574 575 device_unregister(bus_entry->bus->bridge); 576 pci_remove_bus(bus_entry->bus); 577 578 kfree(bus_entry); 579 } 580 pci_unlock_rescan_remove(); 581 } 582 583 static pci_ers_result_t pcifront_common_process(int cmd, 584 struct pcifront_device *pdev, 585 pci_channel_state_t state) 586 { 587 pci_ers_result_t result; 588 struct pci_driver *pdrv; 589 int bus = pdev->sh_info->aer_op.bus; 590 int devfn = pdev->sh_info->aer_op.devfn; 591 int domain = pdev->sh_info->aer_op.domain; 592 struct pci_dev *pcidev; 593 int flag = 0; 594 595 dev_dbg(&pdev->xdev->dev, 596 "pcifront AER process: cmd %x (bus:%x, devfn%x)", 597 cmd, bus, devfn); 598 result = PCI_ERS_RESULT_NONE; 599 600 pcidev = pci_get_domain_bus_and_slot(domain, bus, devfn); 601 if (!pcidev || !pcidev->driver) { 602 dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n"); 603 pci_dev_put(pcidev); 604 return result; 605 } 606 pdrv = pcidev->driver; 607 608 if (pdrv) { 609 if (pdrv->err_handler && pdrv->err_handler->error_detected) { 610 pci_dbg(pcidev, "trying to call AER service\n"); 611 if (pcidev) { 612 flag = 1; 613 switch (cmd) { 614 case XEN_PCI_OP_aer_detected: 615 result = pdrv->err_handler-> 616 error_detected(pcidev, state); 617 break; 618 case XEN_PCI_OP_aer_mmio: 619 result = pdrv->err_handler-> 620 mmio_enabled(pcidev); 621 break; 622 case XEN_PCI_OP_aer_slotreset: 623 result = pdrv->err_handler-> 624 slot_reset(pcidev); 625 break; 626 case XEN_PCI_OP_aer_resume: 627 pdrv->err_handler->resume(pcidev); 628 break; 629 default: 630 dev_err(&pdev->xdev->dev, 631 "bad request in aer recovery " 632 "operation!\n"); 633 634 } 635 } 636 } 637 } 638 if (!flag) 639 result = PCI_ERS_RESULT_NONE; 640 641 return result; 642 } 643 644 645 static void pcifront_do_aer(struct work_struct *data) 646 { 647 struct pcifront_device *pdev = 648 container_of(data, struct pcifront_device, op_work); 649 int cmd = pdev->sh_info->aer_op.cmd; 650 pci_channel_state_t state = 651 (pci_channel_state_t)pdev->sh_info->aer_op.err; 652 653 /*If a pci_conf op is in progress, 654 we have to wait until it is done before service aer op*/ 655 dev_dbg(&pdev->xdev->dev, 656 "pcifront service aer bus %x devfn %x\n", 657 pdev->sh_info->aer_op.bus, pdev->sh_info->aer_op.devfn); 658 659 pdev->sh_info->aer_op.err = pcifront_common_process(cmd, pdev, state); 660 661 /* Post the operation to the guest. */ 662 wmb(); 663 clear_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags); 664 notify_remote_via_evtchn(pdev->evtchn); 665 666 /*in case of we lost an aer request in four lines time_window*/ 667 smp_mb__before_atomic(); 668 clear_bit(_PDEVB_op_active, &pdev->flags); 669 smp_mb__after_atomic(); 670 671 schedule_pcifront_aer_op(pdev); 672 673 } 674 675 static irqreturn_t pcifront_handler_aer(int irq, void *dev) 676 { 677 struct pcifront_device *pdev = dev; 678 schedule_pcifront_aer_op(pdev); 679 return IRQ_HANDLED; 680 } 681 static int pcifront_connect_and_init_dma(struct pcifront_device *pdev) 682 { 683 int err = 0; 684 685 spin_lock(&pcifront_dev_lock); 686 687 if (!pcifront_dev) { 688 dev_info(&pdev->xdev->dev, "Installing PCI frontend\n"); 689 pcifront_dev = pdev; 690 } else 691 err = -EEXIST; 692 693 spin_unlock(&pcifront_dev_lock); 694 695 if (!err && !swiotlb_nr_tbl()) { 696 err = pci_xen_swiotlb_init_late(); 697 if (err) 698 dev_err(&pdev->xdev->dev, "Could not setup SWIOTLB!\n"); 699 } 700 return err; 701 } 702 703 static void pcifront_disconnect(struct pcifront_device *pdev) 704 { 705 spin_lock(&pcifront_dev_lock); 706 707 if (pdev == pcifront_dev) { 708 dev_info(&pdev->xdev->dev, 709 "Disconnecting PCI Frontend Buses\n"); 710 pcifront_dev = NULL; 711 } 712 713 spin_unlock(&pcifront_dev_lock); 714 } 715 static struct pcifront_device *alloc_pdev(struct xenbus_device *xdev) 716 { 717 struct pcifront_device *pdev; 718 719 pdev = kzalloc(sizeof(struct pcifront_device), GFP_KERNEL); 720 if (pdev == NULL) 721 goto out; 722 723 pdev->sh_info = 724 (struct xen_pci_sharedinfo *)__get_free_page(GFP_KERNEL); 725 if (pdev->sh_info == NULL) { 726 kfree(pdev); 727 pdev = NULL; 728 goto out; 729 } 730 pdev->sh_info->flags = 0; 731 732 /*Flag for registering PV AER handler*/ 733 set_bit(_XEN_PCIB_AERHANDLER, (void *)&pdev->sh_info->flags); 734 735 dev_set_drvdata(&xdev->dev, pdev); 736 pdev->xdev = xdev; 737 738 INIT_LIST_HEAD(&pdev->root_buses); 739 740 spin_lock_init(&pdev->sh_info_lock); 741 742 pdev->evtchn = INVALID_EVTCHN; 743 pdev->gnt_ref = INVALID_GRANT_REF; 744 pdev->irq = -1; 745 746 INIT_WORK(&pdev->op_work, pcifront_do_aer); 747 748 dev_dbg(&xdev->dev, "Allocated pdev @ 0x%p pdev->sh_info @ 0x%p\n", 749 pdev, pdev->sh_info); 750 out: 751 return pdev; 752 } 753 754 static void free_pdev(struct pcifront_device *pdev) 755 { 756 dev_dbg(&pdev->xdev->dev, "freeing pdev @ 0x%p\n", pdev); 757 758 pcifront_free_roots(pdev); 759 760 cancel_work_sync(&pdev->op_work); 761 762 if (pdev->irq >= 0) 763 unbind_from_irqhandler(pdev->irq, pdev); 764 765 if (pdev->evtchn != INVALID_EVTCHN) 766 xenbus_free_evtchn(pdev->xdev, pdev->evtchn); 767 768 if (pdev->gnt_ref != INVALID_GRANT_REF) 769 gnttab_end_foreign_access(pdev->gnt_ref, 0 /* r/w page */, 770 (unsigned long)pdev->sh_info); 771 else 772 free_page((unsigned long)pdev->sh_info); 773 774 dev_set_drvdata(&pdev->xdev->dev, NULL); 775 776 kfree(pdev); 777 } 778 779 static int pcifront_publish_info(struct pcifront_device *pdev) 780 { 781 int err = 0; 782 struct xenbus_transaction trans; 783 grant_ref_t gref; 784 785 err = xenbus_grant_ring(pdev->xdev, pdev->sh_info, 1, &gref); 786 if (err < 0) 787 goto out; 788 789 pdev->gnt_ref = gref; 790 791 err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn); 792 if (err) 793 goto out; 794 795 err = bind_evtchn_to_irqhandler(pdev->evtchn, pcifront_handler_aer, 796 0, "pcifront", pdev); 797 798 if (err < 0) 799 return err; 800 801 pdev->irq = err; 802 803 do_publish: 804 err = xenbus_transaction_start(&trans); 805 if (err) { 806 xenbus_dev_fatal(pdev->xdev, err, 807 "Error writing configuration for backend " 808 "(start transaction)"); 809 goto out; 810 } 811 812 err = xenbus_printf(trans, pdev->xdev->nodename, 813 "pci-op-ref", "%u", pdev->gnt_ref); 814 if (!err) 815 err = xenbus_printf(trans, pdev->xdev->nodename, 816 "event-channel", "%u", pdev->evtchn); 817 if (!err) 818 err = xenbus_printf(trans, pdev->xdev->nodename, 819 "magic", XEN_PCI_MAGIC); 820 821 if (err) { 822 xenbus_transaction_end(trans, 1); 823 xenbus_dev_fatal(pdev->xdev, err, 824 "Error writing configuration for backend"); 825 goto out; 826 } else { 827 err = xenbus_transaction_end(trans, 0); 828 if (err == -EAGAIN) 829 goto do_publish; 830 else if (err) { 831 xenbus_dev_fatal(pdev->xdev, err, 832 "Error completing transaction " 833 "for backend"); 834 goto out; 835 } 836 } 837 838 xenbus_switch_state(pdev->xdev, XenbusStateInitialised); 839 840 dev_dbg(&pdev->xdev->dev, "publishing successful!\n"); 841 842 out: 843 return err; 844 } 845 846 static int pcifront_try_connect(struct pcifront_device *pdev) 847 { 848 int err = -EFAULT; 849 int i, num_roots, len; 850 char str[64]; 851 unsigned int domain, bus; 852 853 854 /* Only connect once */ 855 if (xenbus_read_driver_state(pdev->xdev->nodename) != 856 XenbusStateInitialised) 857 goto out; 858 859 err = pcifront_connect_and_init_dma(pdev); 860 if (err && err != -EEXIST) { 861 xenbus_dev_fatal(pdev->xdev, err, 862 "Error setting up PCI Frontend"); 863 goto out; 864 } 865 866 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, 867 "root_num", "%d", &num_roots); 868 if (err == -ENOENT) { 869 xenbus_dev_error(pdev->xdev, err, 870 "No PCI Roots found, trying 0000:00"); 871 err = pcifront_scan_root(pdev, 0, 0); 872 if (err) { 873 xenbus_dev_fatal(pdev->xdev, err, 874 "Error scanning PCI root 0000:00"); 875 goto out; 876 } 877 num_roots = 0; 878 } else if (err != 1) { 879 if (err == 0) 880 err = -EINVAL; 881 xenbus_dev_fatal(pdev->xdev, err, 882 "Error reading number of PCI roots"); 883 goto out; 884 } 885 886 for (i = 0; i < num_roots; i++) { 887 len = snprintf(str, sizeof(str), "root-%d", i); 888 if (unlikely(len >= (sizeof(str) - 1))) { 889 err = -ENOMEM; 890 goto out; 891 } 892 893 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 894 "%x:%x", &domain, &bus); 895 if (err != 2) { 896 if (err >= 0) 897 err = -EINVAL; 898 xenbus_dev_fatal(pdev->xdev, err, 899 "Error reading PCI root %d", i); 900 goto out; 901 } 902 903 err = pcifront_scan_root(pdev, domain, bus); 904 if (err) { 905 xenbus_dev_fatal(pdev->xdev, err, 906 "Error scanning PCI root %04x:%02x", 907 domain, bus); 908 goto out; 909 } 910 } 911 912 err = xenbus_switch_state(pdev->xdev, XenbusStateConnected); 913 914 out: 915 return err; 916 } 917 918 static int pcifront_try_disconnect(struct pcifront_device *pdev) 919 { 920 int err = 0; 921 enum xenbus_state prev_state; 922 923 924 prev_state = xenbus_read_driver_state(pdev->xdev->nodename); 925 926 if (prev_state >= XenbusStateClosing) 927 goto out; 928 929 if (prev_state == XenbusStateConnected) { 930 pcifront_free_roots(pdev); 931 pcifront_disconnect(pdev); 932 } 933 934 err = xenbus_switch_state(pdev->xdev, XenbusStateClosed); 935 936 out: 937 938 return err; 939 } 940 941 static int pcifront_attach_devices(struct pcifront_device *pdev) 942 { 943 int err = -EFAULT; 944 int i, num_roots, len; 945 unsigned int domain, bus; 946 char str[64]; 947 948 if (xenbus_read_driver_state(pdev->xdev->nodename) != 949 XenbusStateReconfiguring) 950 goto out; 951 952 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, 953 "root_num", "%d", &num_roots); 954 if (err == -ENOENT) { 955 xenbus_dev_error(pdev->xdev, err, 956 "No PCI Roots found, trying 0000:00"); 957 err = pcifront_rescan_root(pdev, 0, 0); 958 if (err) { 959 xenbus_dev_fatal(pdev->xdev, err, 960 "Error scanning PCI root 0000:00"); 961 goto out; 962 } 963 num_roots = 0; 964 } else if (err != 1) { 965 if (err == 0) 966 err = -EINVAL; 967 xenbus_dev_fatal(pdev->xdev, err, 968 "Error reading number of PCI roots"); 969 goto out; 970 } 971 972 for (i = 0; i < num_roots; i++) { 973 len = snprintf(str, sizeof(str), "root-%d", i); 974 if (unlikely(len >= (sizeof(str) - 1))) { 975 err = -ENOMEM; 976 goto out; 977 } 978 979 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 980 "%x:%x", &domain, &bus); 981 if (err != 2) { 982 if (err >= 0) 983 err = -EINVAL; 984 xenbus_dev_fatal(pdev->xdev, err, 985 "Error reading PCI root %d", i); 986 goto out; 987 } 988 989 err = pcifront_rescan_root(pdev, domain, bus); 990 if (err) { 991 xenbus_dev_fatal(pdev->xdev, err, 992 "Error scanning PCI root %04x:%02x", 993 domain, bus); 994 goto out; 995 } 996 } 997 998 xenbus_switch_state(pdev->xdev, XenbusStateConnected); 999 1000 out: 1001 return err; 1002 } 1003 1004 static int pcifront_detach_devices(struct pcifront_device *pdev) 1005 { 1006 int err = 0; 1007 int i, num_devs; 1008 unsigned int domain, bus, slot, func; 1009 struct pci_dev *pci_dev; 1010 char str[64]; 1011 1012 if (xenbus_read_driver_state(pdev->xdev->nodename) != 1013 XenbusStateConnected) 1014 goto out; 1015 1016 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, "num_devs", "%d", 1017 &num_devs); 1018 if (err != 1) { 1019 if (err >= 0) 1020 err = -EINVAL; 1021 xenbus_dev_fatal(pdev->xdev, err, 1022 "Error reading number of PCI devices"); 1023 goto out; 1024 } 1025 1026 /* Find devices being detached and remove them. */ 1027 for (i = 0; i < num_devs; i++) { 1028 int l, state; 1029 l = snprintf(str, sizeof(str), "state-%d", i); 1030 if (unlikely(l >= (sizeof(str) - 1))) { 1031 err = -ENOMEM; 1032 goto out; 1033 } 1034 state = xenbus_read_unsigned(pdev->xdev->otherend, str, 1035 XenbusStateUnknown); 1036 1037 if (state != XenbusStateClosing) 1038 continue; 1039 1040 /* Remove device. */ 1041 l = snprintf(str, sizeof(str), "vdev-%d", i); 1042 if (unlikely(l >= (sizeof(str) - 1))) { 1043 err = -ENOMEM; 1044 goto out; 1045 } 1046 err = xenbus_scanf(XBT_NIL, pdev->xdev->otherend, str, 1047 "%x:%x:%x.%x", &domain, &bus, &slot, &func); 1048 if (err != 4) { 1049 if (err >= 0) 1050 err = -EINVAL; 1051 xenbus_dev_fatal(pdev->xdev, err, 1052 "Error reading PCI device %d", i); 1053 goto out; 1054 } 1055 1056 pci_dev = pci_get_domain_bus_and_slot(domain, bus, 1057 PCI_DEVFN(slot, func)); 1058 if (!pci_dev) { 1059 dev_dbg(&pdev->xdev->dev, 1060 "Cannot get PCI device %04x:%02x:%02x.%d\n", 1061 domain, bus, slot, func); 1062 continue; 1063 } 1064 pci_lock_rescan_remove(); 1065 pci_stop_and_remove_bus_device(pci_dev); 1066 pci_dev_put(pci_dev); 1067 pci_unlock_rescan_remove(); 1068 1069 dev_dbg(&pdev->xdev->dev, 1070 "PCI device %04x:%02x:%02x.%d removed.\n", 1071 domain, bus, slot, func); 1072 } 1073 1074 err = xenbus_switch_state(pdev->xdev, XenbusStateReconfiguring); 1075 1076 out: 1077 return err; 1078 } 1079 1080 static void __ref pcifront_backend_changed(struct xenbus_device *xdev, 1081 enum xenbus_state be_state) 1082 { 1083 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev); 1084 1085 switch (be_state) { 1086 case XenbusStateUnknown: 1087 case XenbusStateInitialising: 1088 case XenbusStateInitWait: 1089 case XenbusStateInitialised: 1090 break; 1091 1092 case XenbusStateConnected: 1093 pcifront_try_connect(pdev); 1094 break; 1095 1096 case XenbusStateClosed: 1097 if (xdev->state == XenbusStateClosed) 1098 break; 1099 /* fall through - Missed the backend's CLOSING state. */ 1100 case XenbusStateClosing: 1101 dev_warn(&xdev->dev, "backend going away!\n"); 1102 pcifront_try_disconnect(pdev); 1103 break; 1104 1105 case XenbusStateReconfiguring: 1106 pcifront_detach_devices(pdev); 1107 break; 1108 1109 case XenbusStateReconfigured: 1110 pcifront_attach_devices(pdev); 1111 break; 1112 } 1113 } 1114 1115 static int pcifront_xenbus_probe(struct xenbus_device *xdev, 1116 const struct xenbus_device_id *id) 1117 { 1118 int err = 0; 1119 struct pcifront_device *pdev = alloc_pdev(xdev); 1120 1121 if (pdev == NULL) { 1122 err = -ENOMEM; 1123 xenbus_dev_fatal(xdev, err, 1124 "Error allocating pcifront_device struct"); 1125 goto out; 1126 } 1127 1128 err = pcifront_publish_info(pdev); 1129 if (err) 1130 free_pdev(pdev); 1131 1132 out: 1133 return err; 1134 } 1135 1136 static int pcifront_xenbus_remove(struct xenbus_device *xdev) 1137 { 1138 struct pcifront_device *pdev = dev_get_drvdata(&xdev->dev); 1139 if (pdev) 1140 free_pdev(pdev); 1141 1142 return 0; 1143 } 1144 1145 static const struct xenbus_device_id xenpci_ids[] = { 1146 {"pci"}, 1147 {""}, 1148 }; 1149 1150 static struct xenbus_driver xenpci_driver = { 1151 .name = "pcifront", 1152 .ids = xenpci_ids, 1153 .probe = pcifront_xenbus_probe, 1154 .remove = pcifront_xenbus_remove, 1155 .otherend_changed = pcifront_backend_changed, 1156 }; 1157 1158 static int __init pcifront_init(void) 1159 { 1160 if (!xen_pv_domain() || xen_initial_domain()) 1161 return -ENODEV; 1162 1163 if (!xen_has_pv_devices()) 1164 return -ENODEV; 1165 1166 pci_frontend_registrar(1 /* enable */); 1167 1168 return xenbus_register_frontend(&xenpci_driver); 1169 } 1170 1171 static void __exit pcifront_cleanup(void) 1172 { 1173 xenbus_unregister_driver(&xenpci_driver); 1174 pci_frontend_registrar(0 /* disable */); 1175 } 1176 module_init(pcifront_init); 1177 module_exit(pcifront_cleanup); 1178 1179 MODULE_DESCRIPTION("Xen PCI passthrough frontend."); 1180 MODULE_LICENSE("GPL"); 1181 MODULE_ALIAS("xen:pci"); 1182