1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * PCI Hotplug Driver for PowerPC PowerNV platform. 4 * 5 * Copyright Gavin Shan, IBM Corporation 2016. 6 */ 7 8 #include <linux/libfdt.h> 9 #include <linux/module.h> 10 #include <linux/pci.h> 11 #include <linux/pci_hotplug.h> 12 13 #include <asm/opal.h> 14 #include <asm/pnv-pci.h> 15 #include <asm/ppc-pci.h> 16 17 #define DRIVER_VERSION "0.1" 18 #define DRIVER_AUTHOR "Gavin Shan, IBM Corporation" 19 #define DRIVER_DESC "PowerPC PowerNV PCI Hotplug Driver" 20 21 struct pnv_php_event { 22 bool added; 23 struct pnv_php_slot *php_slot; 24 struct work_struct work; 25 }; 26 27 static LIST_HEAD(pnv_php_slot_list); 28 static DEFINE_SPINLOCK(pnv_php_lock); 29 30 static void pnv_php_register(struct device_node *dn); 31 static void pnv_php_unregister_one(struct device_node *dn); 32 static void pnv_php_unregister(struct device_node *dn); 33 34 static void pnv_php_disable_irq(struct pnv_php_slot *php_slot, 35 bool disable_device) 36 { 37 struct pci_dev *pdev = php_slot->pdev; 38 int irq = php_slot->irq; 39 u16 ctrl; 40 41 if (php_slot->irq > 0) { 42 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &ctrl); 43 ctrl &= ~(PCI_EXP_SLTCTL_HPIE | 44 PCI_EXP_SLTCTL_PDCE | 45 PCI_EXP_SLTCTL_DLLSCE); 46 pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, ctrl); 47 48 free_irq(php_slot->irq, php_slot); 49 php_slot->irq = 0; 50 } 51 52 if (php_slot->wq) { 53 destroy_workqueue(php_slot->wq); 54 php_slot->wq = NULL; 55 } 56 57 if (disable_device || irq > 0) { 58 if (pdev->msix_enabled) 59 pci_disable_msix(pdev); 60 else if (pdev->msi_enabled) 61 pci_disable_msi(pdev); 62 63 pci_disable_device(pdev); 64 } 65 } 66 67 static void pnv_php_free_slot(struct kref *kref) 68 { 69 struct pnv_php_slot *php_slot = container_of(kref, 70 struct pnv_php_slot, kref); 71 72 WARN_ON(!list_empty(&php_slot->children)); 73 pnv_php_disable_irq(php_slot, false); 74 kfree(php_slot->name); 75 kfree(php_slot); 76 } 77 78 static inline void pnv_php_put_slot(struct pnv_php_slot *php_slot) 79 { 80 81 if (!php_slot) 82 return; 83 84 kref_put(&php_slot->kref, pnv_php_free_slot); 85 } 86 87 static struct pnv_php_slot *pnv_php_match(struct device_node *dn, 88 struct pnv_php_slot *php_slot) 89 { 90 struct pnv_php_slot *target, *tmp; 91 92 if (php_slot->dn == dn) { 93 kref_get(&php_slot->kref); 94 return php_slot; 95 } 96 97 list_for_each_entry(tmp, &php_slot->children, link) { 98 target = pnv_php_match(dn, tmp); 99 if (target) 100 return target; 101 } 102 103 return NULL; 104 } 105 106 struct pnv_php_slot *pnv_php_find_slot(struct device_node *dn) 107 { 108 struct pnv_php_slot *php_slot, *tmp; 109 unsigned long flags; 110 111 spin_lock_irqsave(&pnv_php_lock, flags); 112 list_for_each_entry(tmp, &pnv_php_slot_list, link) { 113 php_slot = pnv_php_match(dn, tmp); 114 if (php_slot) { 115 spin_unlock_irqrestore(&pnv_php_lock, flags); 116 return php_slot; 117 } 118 } 119 spin_unlock_irqrestore(&pnv_php_lock, flags); 120 121 return NULL; 122 } 123 EXPORT_SYMBOL_GPL(pnv_php_find_slot); 124 125 /* 126 * Remove pdn for all children of the indicated device node. 127 * The function should remove pdn in a depth-first manner. 128 */ 129 static void pnv_php_rmv_pdns(struct device_node *dn) 130 { 131 struct device_node *child; 132 133 for_each_child_of_node(dn, child) { 134 pnv_php_rmv_pdns(child); 135 136 pci_remove_device_node_info(child); 137 } 138 } 139 140 /* 141 * Detach all child nodes of the indicated device nodes. The 142 * function should handle device nodes in depth-first manner. 143 * 144 * We should not invoke of_node_release() as the memory for 145 * individual device node is part of large memory block. The 146 * large block is allocated from memblock (system bootup) or 147 * kmalloc() when unflattening the device tree by OF changeset. 148 * We can not free the large block allocated from memblock. For 149 * later case, it should be released at once. 150 */ 151 static void pnv_php_detach_device_nodes(struct device_node *parent) 152 { 153 struct device_node *dn; 154 int refcount; 155 156 for_each_child_of_node(parent, dn) { 157 pnv_php_detach_device_nodes(dn); 158 159 of_node_put(dn); 160 refcount = kref_read(&dn->kobj.kref); 161 if (refcount != 1) 162 pr_warn("Invalid refcount %d on <%pOF>\n", 163 refcount, dn); 164 165 of_detach_node(dn); 166 } 167 } 168 169 static void pnv_php_rmv_devtree(struct pnv_php_slot *php_slot) 170 { 171 pnv_php_rmv_pdns(php_slot->dn); 172 173 /* 174 * Decrease the refcount if the device nodes were created 175 * through OF changeset before detaching them. 176 */ 177 if (php_slot->fdt) 178 of_changeset_destroy(&php_slot->ocs); 179 pnv_php_detach_device_nodes(php_slot->dn); 180 181 if (php_slot->fdt) { 182 kfree(php_slot->dt); 183 kfree(php_slot->fdt); 184 php_slot->dt = NULL; 185 php_slot->dn->child = NULL; 186 php_slot->fdt = NULL; 187 } 188 } 189 190 /* 191 * As the nodes in OF changeset are applied in reverse order, we 192 * need revert the nodes in advance so that we have correct node 193 * order after the changeset is applied. 194 */ 195 static void pnv_php_reverse_nodes(struct device_node *parent) 196 { 197 struct device_node *child, *next; 198 199 /* In-depth first */ 200 for_each_child_of_node(parent, child) 201 pnv_php_reverse_nodes(child); 202 203 /* Reverse the nodes in the child list */ 204 child = parent->child; 205 parent->child = NULL; 206 while (child) { 207 next = child->sibling; 208 209 child->sibling = parent->child; 210 parent->child = child; 211 child = next; 212 } 213 } 214 215 static int pnv_php_populate_changeset(struct of_changeset *ocs, 216 struct device_node *dn) 217 { 218 struct device_node *child; 219 int ret = 0; 220 221 for_each_child_of_node(dn, child) { 222 ret = of_changeset_attach_node(ocs, child); 223 if (ret) { 224 of_node_put(child); 225 break; 226 } 227 228 ret = pnv_php_populate_changeset(ocs, child); 229 if (ret) { 230 of_node_put(child); 231 break; 232 } 233 } 234 235 return ret; 236 } 237 238 static void *pnv_php_add_one_pdn(struct device_node *dn, void *data) 239 { 240 struct pci_controller *hose = (struct pci_controller *)data; 241 struct pci_dn *pdn; 242 243 pdn = pci_add_device_node_info(hose, dn); 244 if (!pdn) 245 return ERR_PTR(-ENOMEM); 246 247 return NULL; 248 } 249 250 static void pnv_php_add_pdns(struct pnv_php_slot *slot) 251 { 252 struct pci_controller *hose = pci_bus_to_host(slot->bus); 253 254 pci_traverse_device_nodes(slot->dn, pnv_php_add_one_pdn, hose); 255 } 256 257 static int pnv_php_add_devtree(struct pnv_php_slot *php_slot) 258 { 259 void *fdt, *fdt1, *dt; 260 int ret; 261 262 /* We don't know the FDT blob size. We try to get it through 263 * maximal memory chunk and then copy it to another chunk that 264 * fits the real size. 265 */ 266 fdt1 = kzalloc(0x10000, GFP_KERNEL); 267 if (!fdt1) { 268 ret = -ENOMEM; 269 goto out; 270 } 271 272 ret = pnv_pci_get_device_tree(php_slot->dn->phandle, fdt1, 0x10000); 273 if (ret) { 274 pci_warn(php_slot->pdev, "Error %d getting FDT blob\n", ret); 275 goto free_fdt1; 276 } 277 278 fdt = kmemdup(fdt1, fdt_totalsize(fdt1), GFP_KERNEL); 279 if (!fdt) { 280 ret = -ENOMEM; 281 goto free_fdt1; 282 } 283 284 /* Unflatten device tree blob */ 285 dt = of_fdt_unflatten_tree(fdt, php_slot->dn, NULL); 286 if (!dt) { 287 ret = -EINVAL; 288 pci_warn(php_slot->pdev, "Cannot unflatten FDT\n"); 289 goto free_fdt; 290 } 291 292 /* Initialize and apply the changeset */ 293 of_changeset_init(&php_slot->ocs); 294 pnv_php_reverse_nodes(php_slot->dn); 295 ret = pnv_php_populate_changeset(&php_slot->ocs, php_slot->dn); 296 if (ret) { 297 pnv_php_reverse_nodes(php_slot->dn); 298 pci_warn(php_slot->pdev, "Error %d populating changeset\n", 299 ret); 300 goto free_dt; 301 } 302 303 php_slot->dn->child = NULL; 304 ret = of_changeset_apply(&php_slot->ocs); 305 if (ret) { 306 pci_warn(php_slot->pdev, "Error %d applying changeset\n", ret); 307 goto destroy_changeset; 308 } 309 310 /* Add device node firmware data */ 311 pnv_php_add_pdns(php_slot); 312 php_slot->fdt = fdt; 313 php_slot->dt = dt; 314 kfree(fdt1); 315 goto out; 316 317 destroy_changeset: 318 of_changeset_destroy(&php_slot->ocs); 319 free_dt: 320 kfree(dt); 321 php_slot->dn->child = NULL; 322 free_fdt: 323 kfree(fdt); 324 free_fdt1: 325 kfree(fdt1); 326 out: 327 return ret; 328 } 329 330 static inline struct pnv_php_slot *to_pnv_php_slot(struct hotplug_slot *slot) 331 { 332 return container_of(slot, struct pnv_php_slot, slot); 333 } 334 335 int pnv_php_set_slot_power_state(struct hotplug_slot *slot, 336 uint8_t state) 337 { 338 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); 339 struct opal_msg msg; 340 int ret; 341 342 ret = pnv_pci_set_power_state(php_slot->id, state, &msg); 343 if (ret > 0) { 344 if (be64_to_cpu(msg.params[1]) != php_slot->dn->phandle || 345 be64_to_cpu(msg.params[2]) != state || 346 be64_to_cpu(msg.params[3]) != OPAL_SUCCESS) { 347 pci_warn(php_slot->pdev, "Wrong msg (%lld, %lld, %lld)\n", 348 be64_to_cpu(msg.params[1]), 349 be64_to_cpu(msg.params[2]), 350 be64_to_cpu(msg.params[3])); 351 return -ENOMSG; 352 } 353 } else if (ret < 0) { 354 pci_warn(php_slot->pdev, "Error %d powering %s\n", 355 ret, (state == OPAL_PCI_SLOT_POWER_ON) ? "on" : "off"); 356 return ret; 357 } 358 359 if (state == OPAL_PCI_SLOT_POWER_OFF || state == OPAL_PCI_SLOT_OFFLINE) 360 pnv_php_rmv_devtree(php_slot); 361 else 362 ret = pnv_php_add_devtree(php_slot); 363 364 return ret; 365 } 366 EXPORT_SYMBOL_GPL(pnv_php_set_slot_power_state); 367 368 static int pnv_php_get_power_state(struct hotplug_slot *slot, u8 *state) 369 { 370 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); 371 uint8_t power_state = OPAL_PCI_SLOT_POWER_ON; 372 int ret; 373 374 /* 375 * Retrieve power status from firmware. If we fail 376 * getting that, the power status fails back to 377 * be on. 378 */ 379 ret = pnv_pci_get_power_state(php_slot->id, &power_state); 380 if (ret) { 381 pci_warn(php_slot->pdev, "Error %d getting power status\n", 382 ret); 383 } else { 384 *state = power_state; 385 } 386 387 return 0; 388 } 389 390 static int pnv_php_get_adapter_state(struct hotplug_slot *slot, u8 *state) 391 { 392 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); 393 uint8_t presence = OPAL_PCI_SLOT_EMPTY; 394 int ret; 395 396 /* 397 * Retrieve presence status from firmware. If we can't 398 * get that, it will fail back to be empty. 399 */ 400 ret = pnv_pci_get_presence_state(php_slot->id, &presence); 401 if (ret >= 0) { 402 *state = presence; 403 ret = 0; 404 } else { 405 pci_warn(php_slot->pdev, "Error %d getting presence\n", ret); 406 } 407 408 return ret; 409 } 410 411 static int pnv_php_get_attention_state(struct hotplug_slot *slot, u8 *state) 412 { 413 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); 414 415 *state = php_slot->attention_state; 416 return 0; 417 } 418 419 static int pnv_php_set_attention_state(struct hotplug_slot *slot, u8 state) 420 { 421 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); 422 423 /* FIXME: Make it real once firmware supports it */ 424 php_slot->attention_state = state; 425 426 return 0; 427 } 428 429 static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan) 430 { 431 struct hotplug_slot *slot = &php_slot->slot; 432 uint8_t presence = OPAL_PCI_SLOT_EMPTY; 433 uint8_t power_status = OPAL_PCI_SLOT_POWER_ON; 434 int ret; 435 436 /* Check if the slot has been configured */ 437 if (php_slot->state != PNV_PHP_STATE_REGISTERED) 438 return 0; 439 440 /* Retrieve slot presence status */ 441 ret = pnv_php_get_adapter_state(slot, &presence); 442 if (ret) 443 return ret; 444 445 /* 446 * Proceed if there have nothing behind the slot. However, 447 * we should leave the slot in registered state at the 448 * beginning. Otherwise, the PCI devices inserted afterwards 449 * won't be probed and populated. 450 */ 451 if (presence == OPAL_PCI_SLOT_EMPTY) { 452 if (!php_slot->power_state_check) { 453 php_slot->power_state_check = true; 454 455 return 0; 456 } 457 458 goto scan; 459 } 460 461 /* 462 * If the power supply to the slot is off, we can't detect 463 * adapter presence state. That means we have to turn the 464 * slot on before going to probe slot's presence state. 465 * 466 * On the first time, we don't change the power status to 467 * boost system boot with assumption that the firmware 468 * supplies consistent slot power status: empty slot always 469 * has its power off and non-empty slot has its power on. 470 */ 471 if (!php_slot->power_state_check) { 472 php_slot->power_state_check = true; 473 474 ret = pnv_php_get_power_state(slot, &power_status); 475 if (ret) 476 return ret; 477 478 if (power_status != OPAL_PCI_SLOT_POWER_ON) 479 return 0; 480 } 481 482 /* Check the power status. Scan the slot if it is already on */ 483 ret = pnv_php_get_power_state(slot, &power_status); 484 if (ret) 485 return ret; 486 487 if (power_status == OPAL_PCI_SLOT_POWER_ON) 488 goto scan; 489 490 /* Power is off, turn it on and then scan the slot */ 491 ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_ON); 492 if (ret) 493 return ret; 494 495 scan: 496 if (presence == OPAL_PCI_SLOT_PRESENT) { 497 if (rescan) { 498 pci_lock_rescan_remove(); 499 pci_hp_add_devices(php_slot->bus); 500 pci_unlock_rescan_remove(); 501 } 502 503 /* Rescan for child hotpluggable slots */ 504 php_slot->state = PNV_PHP_STATE_POPULATED; 505 if (rescan) 506 pnv_php_register(php_slot->dn); 507 } else { 508 php_slot->state = PNV_PHP_STATE_POPULATED; 509 } 510 511 return 0; 512 } 513 514 static int pnv_php_enable_slot(struct hotplug_slot *slot) 515 { 516 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); 517 518 return pnv_php_enable(php_slot, true); 519 } 520 521 static int pnv_php_disable_slot(struct hotplug_slot *slot) 522 { 523 struct pnv_php_slot *php_slot = to_pnv_php_slot(slot); 524 int ret; 525 526 if (php_slot->state != PNV_PHP_STATE_POPULATED) 527 return 0; 528 529 /* Remove all devices behind the slot */ 530 pci_lock_rescan_remove(); 531 pci_hp_remove_devices(php_slot->bus); 532 pci_unlock_rescan_remove(); 533 534 /* Detach the child hotpluggable slots */ 535 pnv_php_unregister(php_slot->dn); 536 537 /* Notify firmware and remove device nodes */ 538 ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_OFF); 539 540 php_slot->state = PNV_PHP_STATE_REGISTERED; 541 return ret; 542 } 543 544 static const struct hotplug_slot_ops php_slot_ops = { 545 .get_power_status = pnv_php_get_power_state, 546 .get_adapter_status = pnv_php_get_adapter_state, 547 .get_attention_status = pnv_php_get_attention_state, 548 .set_attention_status = pnv_php_set_attention_state, 549 .enable_slot = pnv_php_enable_slot, 550 .disable_slot = pnv_php_disable_slot, 551 }; 552 553 static void pnv_php_release(struct pnv_php_slot *php_slot) 554 { 555 unsigned long flags; 556 557 /* Remove from global or child list */ 558 spin_lock_irqsave(&pnv_php_lock, flags); 559 list_del(&php_slot->link); 560 spin_unlock_irqrestore(&pnv_php_lock, flags); 561 562 /* Detach from parent */ 563 pnv_php_put_slot(php_slot); 564 pnv_php_put_slot(php_slot->parent); 565 } 566 567 static struct pnv_php_slot *pnv_php_alloc_slot(struct device_node *dn) 568 { 569 struct pnv_php_slot *php_slot; 570 struct pci_bus *bus; 571 const char *label; 572 uint64_t id; 573 int ret; 574 575 ret = of_property_read_string(dn, "ibm,slot-label", &label); 576 if (ret) 577 return NULL; 578 579 if (pnv_pci_get_slot_id(dn, &id)) 580 return NULL; 581 582 bus = pci_find_bus_by_node(dn); 583 if (!bus) 584 return NULL; 585 586 php_slot = kzalloc(sizeof(*php_slot), GFP_KERNEL); 587 if (!php_slot) 588 return NULL; 589 590 php_slot->name = kstrdup(label, GFP_KERNEL); 591 if (!php_slot->name) { 592 kfree(php_slot); 593 return NULL; 594 } 595 596 if (dn->child && PCI_DN(dn->child)) 597 php_slot->slot_no = PCI_SLOT(PCI_DN(dn->child)->devfn); 598 else 599 php_slot->slot_no = -1; /* Placeholder slot */ 600 601 kref_init(&php_slot->kref); 602 php_slot->state = PNV_PHP_STATE_INITIALIZED; 603 php_slot->dn = dn; 604 php_slot->pdev = bus->self; 605 php_slot->bus = bus; 606 php_slot->id = id; 607 php_slot->power_state_check = false; 608 php_slot->slot.ops = &php_slot_ops; 609 610 INIT_LIST_HEAD(&php_slot->children); 611 INIT_LIST_HEAD(&php_slot->link); 612 613 return php_slot; 614 } 615 616 static int pnv_php_register_slot(struct pnv_php_slot *php_slot) 617 { 618 struct pnv_php_slot *parent; 619 struct device_node *dn = php_slot->dn; 620 unsigned long flags; 621 int ret; 622 623 /* Check if the slot is registered or not */ 624 parent = pnv_php_find_slot(php_slot->dn); 625 if (parent) { 626 pnv_php_put_slot(parent); 627 return -EEXIST; 628 } 629 630 /* Register PCI slot */ 631 ret = pci_hp_register(&php_slot->slot, php_slot->bus, 632 php_slot->slot_no, php_slot->name); 633 if (ret) { 634 pci_warn(php_slot->pdev, "Error %d registering slot\n", ret); 635 return ret; 636 } 637 638 /* Attach to the parent's child list or global list */ 639 while ((dn = of_get_parent(dn))) { 640 if (!PCI_DN(dn)) { 641 of_node_put(dn); 642 break; 643 } 644 645 parent = pnv_php_find_slot(dn); 646 if (parent) { 647 of_node_put(dn); 648 break; 649 } 650 651 of_node_put(dn); 652 } 653 654 spin_lock_irqsave(&pnv_php_lock, flags); 655 php_slot->parent = parent; 656 if (parent) 657 list_add_tail(&php_slot->link, &parent->children); 658 else 659 list_add_tail(&php_slot->link, &pnv_php_slot_list); 660 spin_unlock_irqrestore(&pnv_php_lock, flags); 661 662 php_slot->state = PNV_PHP_STATE_REGISTERED; 663 return 0; 664 } 665 666 static int pnv_php_enable_msix(struct pnv_php_slot *php_slot) 667 { 668 struct pci_dev *pdev = php_slot->pdev; 669 struct msix_entry entry; 670 int nr_entries, ret; 671 u16 pcie_flag; 672 673 /* Get total number of MSIx entries */ 674 nr_entries = pci_msix_vec_count(pdev); 675 if (nr_entries < 0) 676 return nr_entries; 677 678 /* Check hotplug MSIx entry is in range */ 679 pcie_capability_read_word(pdev, PCI_EXP_FLAGS, &pcie_flag); 680 entry.entry = (pcie_flag & PCI_EXP_FLAGS_IRQ) >> 9; 681 if (entry.entry >= nr_entries) 682 return -ERANGE; 683 684 /* Enable MSIx */ 685 ret = pci_enable_msix_exact(pdev, &entry, 1); 686 if (ret) { 687 pci_warn(pdev, "Error %d enabling MSIx\n", ret); 688 return ret; 689 } 690 691 return entry.vector; 692 } 693 694 static void pnv_php_event_handler(struct work_struct *work) 695 { 696 struct pnv_php_event *event = 697 container_of(work, struct pnv_php_event, work); 698 struct pnv_php_slot *php_slot = event->php_slot; 699 700 if (event->added) 701 pnv_php_enable_slot(&php_slot->slot); 702 else 703 pnv_php_disable_slot(&php_slot->slot); 704 705 kfree(event); 706 } 707 708 static irqreturn_t pnv_php_interrupt(int irq, void *data) 709 { 710 struct pnv_php_slot *php_slot = data; 711 struct pci_dev *pchild, *pdev = php_slot->pdev; 712 struct eeh_dev *edev; 713 struct eeh_pe *pe; 714 struct pnv_php_event *event; 715 u16 sts, lsts; 716 u8 presence; 717 bool added; 718 unsigned long flags; 719 int ret; 720 721 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &sts); 722 sts &= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC); 723 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, sts); 724 if (sts & PCI_EXP_SLTSTA_DLLSC) { 725 pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lsts); 726 added = !!(lsts & PCI_EXP_LNKSTA_DLLLA); 727 } else if (!(php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) && 728 (sts & PCI_EXP_SLTSTA_PDC)) { 729 ret = pnv_pci_get_presence_state(php_slot->id, &presence); 730 if (ret) { 731 pci_warn(pdev, "PCI slot [%s] error %d getting presence (0x%04x), to retry the operation.\n", 732 php_slot->name, ret, sts); 733 return IRQ_HANDLED; 734 } 735 736 added = !!(presence == OPAL_PCI_SLOT_PRESENT); 737 } else { 738 return IRQ_NONE; 739 } 740 741 /* Freeze the removed PE to avoid unexpected error reporting */ 742 if (!added) { 743 pchild = list_first_entry_or_null(&php_slot->bus->devices, 744 struct pci_dev, bus_list); 745 edev = pchild ? pci_dev_to_eeh_dev(pchild) : NULL; 746 pe = edev ? edev->pe : NULL; 747 if (pe) { 748 eeh_serialize_lock(&flags); 749 eeh_pe_mark_isolated(pe); 750 eeh_serialize_unlock(flags); 751 eeh_pe_set_option(pe, EEH_OPT_FREEZE_PE); 752 } 753 } 754 755 /* 756 * The PE is left in frozen state if the event is missed. It's 757 * fine as the PCI devices (PE) aren't functional any more. 758 */ 759 event = kzalloc(sizeof(*event), GFP_ATOMIC); 760 if (!event) { 761 pci_warn(pdev, "PCI slot [%s] missed hotplug event 0x%04x\n", 762 php_slot->name, sts); 763 return IRQ_HANDLED; 764 } 765 766 pci_info(pdev, "PCI slot [%s] %s (IRQ: %d)\n", 767 php_slot->name, added ? "added" : "removed", irq); 768 INIT_WORK(&event->work, pnv_php_event_handler); 769 event->added = added; 770 event->php_slot = php_slot; 771 queue_work(php_slot->wq, &event->work); 772 773 return IRQ_HANDLED; 774 } 775 776 static void pnv_php_init_irq(struct pnv_php_slot *php_slot, int irq) 777 { 778 struct pci_dev *pdev = php_slot->pdev; 779 u32 broken_pdc = 0; 780 u16 sts, ctrl; 781 int ret; 782 783 /* Allocate workqueue */ 784 php_slot->wq = alloc_workqueue("pciehp-%s", 0, 0, php_slot->name); 785 if (!php_slot->wq) { 786 pci_warn(pdev, "Cannot alloc workqueue\n"); 787 pnv_php_disable_irq(php_slot, true); 788 return; 789 } 790 791 /* Check PDC (Presence Detection Change) is broken or not */ 792 ret = of_property_read_u32(php_slot->dn, "ibm,slot-broken-pdc", 793 &broken_pdc); 794 if (!ret && broken_pdc) 795 php_slot->flags |= PNV_PHP_FLAG_BROKEN_PDC; 796 797 /* Clear pending interrupts */ 798 pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &sts); 799 if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) 800 sts |= PCI_EXP_SLTSTA_DLLSC; 801 else 802 sts |= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC); 803 pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, sts); 804 805 /* Request the interrupt */ 806 ret = request_irq(irq, pnv_php_interrupt, IRQF_SHARED, 807 php_slot->name, php_slot); 808 if (ret) { 809 pnv_php_disable_irq(php_slot, true); 810 pci_warn(pdev, "Error %d enabling IRQ %d\n", ret, irq); 811 return; 812 } 813 814 /* Enable the interrupts */ 815 pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &ctrl); 816 if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) { 817 ctrl &= ~PCI_EXP_SLTCTL_PDCE; 818 ctrl |= (PCI_EXP_SLTCTL_HPIE | 819 PCI_EXP_SLTCTL_DLLSCE); 820 } else { 821 ctrl |= (PCI_EXP_SLTCTL_HPIE | 822 PCI_EXP_SLTCTL_PDCE | 823 PCI_EXP_SLTCTL_DLLSCE); 824 } 825 pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, ctrl); 826 827 /* The interrupt is initialized successfully when @irq is valid */ 828 php_slot->irq = irq; 829 } 830 831 static void pnv_php_enable_irq(struct pnv_php_slot *php_slot) 832 { 833 struct pci_dev *pdev = php_slot->pdev; 834 int irq, ret; 835 836 /* 837 * The MSI/MSIx interrupt might have been occupied by other 838 * drivers. Don't populate the surprise hotplug capability 839 * in that case. 840 */ 841 if (pci_dev_msi_enabled(pdev)) 842 return; 843 844 ret = pci_enable_device(pdev); 845 if (ret) { 846 pci_warn(pdev, "Error %d enabling device\n", ret); 847 return; 848 } 849 850 pci_set_master(pdev); 851 852 /* Enable MSIx interrupt */ 853 irq = pnv_php_enable_msix(php_slot); 854 if (irq > 0) { 855 pnv_php_init_irq(php_slot, irq); 856 return; 857 } 858 859 /* 860 * Use MSI if MSIx doesn't work. Fail back to legacy INTx 861 * if MSI doesn't work either 862 */ 863 ret = pci_enable_msi(pdev); 864 if (!ret || pdev->irq) { 865 irq = pdev->irq; 866 pnv_php_init_irq(php_slot, irq); 867 } 868 } 869 870 static int pnv_php_register_one(struct device_node *dn) 871 { 872 struct pnv_php_slot *php_slot; 873 u32 prop32; 874 int ret; 875 876 /* Check if it's hotpluggable slot */ 877 ret = of_property_read_u32(dn, "ibm,slot-pluggable", &prop32); 878 if (ret || !prop32) 879 return -ENXIO; 880 881 ret = of_property_read_u32(dn, "ibm,reset-by-firmware", &prop32); 882 if (ret || !prop32) 883 return -ENXIO; 884 885 php_slot = pnv_php_alloc_slot(dn); 886 if (!php_slot) 887 return -ENODEV; 888 889 ret = pnv_php_register_slot(php_slot); 890 if (ret) 891 goto free_slot; 892 893 ret = pnv_php_enable(php_slot, false); 894 if (ret) 895 goto unregister_slot; 896 897 /* Enable interrupt if the slot supports surprise hotplug */ 898 ret = of_property_read_u32(dn, "ibm,slot-surprise-pluggable", &prop32); 899 if (!ret && prop32) 900 pnv_php_enable_irq(php_slot); 901 902 return 0; 903 904 unregister_slot: 905 pnv_php_unregister_one(php_slot->dn); 906 free_slot: 907 pnv_php_put_slot(php_slot); 908 return ret; 909 } 910 911 static void pnv_php_register(struct device_node *dn) 912 { 913 struct device_node *child; 914 915 /* 916 * The parent slots should be registered before their 917 * child slots. 918 */ 919 for_each_child_of_node(dn, child) { 920 pnv_php_register_one(child); 921 pnv_php_register(child); 922 } 923 } 924 925 static void pnv_php_unregister_one(struct device_node *dn) 926 { 927 struct pnv_php_slot *php_slot; 928 929 php_slot = pnv_php_find_slot(dn); 930 if (!php_slot) 931 return; 932 933 php_slot->state = PNV_PHP_STATE_OFFLINE; 934 pci_hp_deregister(&php_slot->slot); 935 pnv_php_release(php_slot); 936 pnv_php_put_slot(php_slot); 937 } 938 939 static void pnv_php_unregister(struct device_node *dn) 940 { 941 struct device_node *child; 942 943 /* The child slots should go before their parent slots */ 944 for_each_child_of_node(dn, child) { 945 pnv_php_unregister(child); 946 pnv_php_unregister_one(child); 947 } 948 } 949 950 static int __init pnv_php_init(void) 951 { 952 struct device_node *dn; 953 954 pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n"); 955 for_each_compatible_node(dn, NULL, "ibm,ioda2-phb") 956 pnv_php_register(dn); 957 958 return 0; 959 } 960 961 static void __exit pnv_php_exit(void) 962 { 963 struct device_node *dn; 964 965 for_each_compatible_node(dn, NULL, "ibm,ioda2-phb") 966 pnv_php_unregister(dn); 967 } 968 969 module_init(pnv_php_init); 970 module_exit(pnv_php_exit); 971 972 MODULE_VERSION(DRIVER_VERSION); 973 MODULE_LICENSE("GPL v2"); 974 MODULE_AUTHOR(DRIVER_AUTHOR); 975 MODULE_DESCRIPTION(DRIVER_DESC); 976