1 /* 2 * CompactPCI Hot Plug Driver 3 * 4 * Copyright (C) 2002,2005 SOMA Networks, Inc. 5 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com) 6 * Copyright (C) 2001 IBM Corp. 7 * 8 * All rights reserved. 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or (at 13 * your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, but 16 * WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or 18 * NON INFRINGEMENT. See the GNU General Public License for more 19 * details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 24 * 25 * Send feedback to <scottm@somanetworks.com> 26 */ 27 28 #include <linux/module.h> 29 #include <linux/kernel.h> 30 #include <linux/slab.h> 31 #include <linux/pci.h> 32 #include <linux/pci_hotplug.h> 33 #include <linux/init.h> 34 #include <linux/interrupt.h> 35 #include <linux/atomic.h> 36 #include <linux/delay.h> 37 #include <linux/kthread.h> 38 #include "cpci_hotplug.h" 39 40 #define DRIVER_AUTHOR "Scott Murray <scottm@somanetworks.com>" 41 #define DRIVER_DESC "CompactPCI Hot Plug Core" 42 43 #define MY_NAME "cpci_hotplug" 44 45 #define dbg(format, arg...) \ 46 do { \ 47 if (cpci_debug) \ 48 printk (KERN_DEBUG "%s: " format "\n", \ 49 MY_NAME , ## arg); \ 50 } while (0) 51 #define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME , ## arg) 52 #define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME , ## arg) 53 #define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME , ## arg) 54 55 /* local variables */ 56 static DECLARE_RWSEM(list_rwsem); 57 static LIST_HEAD(slot_list); 58 static int slots; 59 static atomic_t extracting; 60 int cpci_debug; 61 static struct cpci_hp_controller *controller; 62 static struct task_struct *cpci_thread; 63 static int thread_finished; 64 65 static int enable_slot(struct hotplug_slot *slot); 66 static int disable_slot(struct hotplug_slot *slot); 67 static int set_attention_status(struct hotplug_slot *slot, u8 value); 68 static int get_power_status(struct hotplug_slot *slot, u8 *value); 69 static int get_attention_status(struct hotplug_slot *slot, u8 *value); 70 static int get_adapter_status(struct hotplug_slot *slot, u8 *value); 71 static int get_latch_status(struct hotplug_slot *slot, u8 *value); 72 73 static struct hotplug_slot_ops cpci_hotplug_slot_ops = { 74 .enable_slot = enable_slot, 75 .disable_slot = disable_slot, 76 .set_attention_status = set_attention_status, 77 .get_power_status = get_power_status, 78 .get_attention_status = get_attention_status, 79 .get_adapter_status = get_adapter_status, 80 .get_latch_status = get_latch_status, 81 }; 82 83 static int 84 update_latch_status(struct hotplug_slot *hotplug_slot, u8 value) 85 { 86 struct hotplug_slot_info info; 87 88 memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info)); 89 info.latch_status = value; 90 return pci_hp_change_slot_info(hotplug_slot, &info); 91 } 92 93 static int 94 update_adapter_status(struct hotplug_slot *hotplug_slot, u8 value) 95 { 96 struct hotplug_slot_info info; 97 98 memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info)); 99 info.adapter_status = value; 100 return pci_hp_change_slot_info(hotplug_slot, &info); 101 } 102 103 static int 104 enable_slot(struct hotplug_slot *hotplug_slot) 105 { 106 struct slot *slot = hotplug_slot->private; 107 int retval = 0; 108 109 dbg("%s - physical_slot = %s", __func__, slot_name(slot)); 110 111 if (controller->ops->set_power) 112 retval = controller->ops->set_power(slot, 1); 113 return retval; 114 } 115 116 static int 117 disable_slot(struct hotplug_slot *hotplug_slot) 118 { 119 struct slot *slot = hotplug_slot->private; 120 int retval = 0; 121 122 dbg("%s - physical_slot = %s", __func__, slot_name(slot)); 123 124 down_write(&list_rwsem); 125 126 /* Unconfigure device */ 127 dbg("%s - unconfiguring slot %s", __func__, slot_name(slot)); 128 if ((retval = cpci_unconfigure_slot(slot))) { 129 err("%s - could not unconfigure slot %s", 130 __func__, slot_name(slot)); 131 goto disable_error; 132 } 133 dbg("%s - finished unconfiguring slot %s", __func__, slot_name(slot)); 134 135 /* Clear EXT (by setting it) */ 136 if (cpci_clear_ext(slot)) { 137 err("%s - could not clear EXT for slot %s", 138 __func__, slot_name(slot)); 139 retval = -ENODEV; 140 goto disable_error; 141 } 142 cpci_led_on(slot); 143 144 if (controller->ops->set_power) 145 if ((retval = controller->ops->set_power(slot, 0))) 146 goto disable_error; 147 148 if (update_adapter_status(slot->hotplug_slot, 0)) 149 warn("failure to update adapter file"); 150 151 if (slot->extracting) { 152 slot->extracting = 0; 153 atomic_dec(&extracting); 154 } 155 disable_error: 156 up_write(&list_rwsem); 157 return retval; 158 } 159 160 static u8 161 cpci_get_power_status(struct slot *slot) 162 { 163 u8 power = 1; 164 165 if (controller->ops->get_power) 166 power = controller->ops->get_power(slot); 167 return power; 168 } 169 170 static int 171 get_power_status(struct hotplug_slot *hotplug_slot, u8 *value) 172 { 173 struct slot *slot = hotplug_slot->private; 174 175 *value = cpci_get_power_status(slot); 176 return 0; 177 } 178 179 static int 180 get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value) 181 { 182 struct slot *slot = hotplug_slot->private; 183 184 *value = cpci_get_attention_status(slot); 185 return 0; 186 } 187 188 static int 189 set_attention_status(struct hotplug_slot *hotplug_slot, u8 status) 190 { 191 return cpci_set_attention_status(hotplug_slot->private, status); 192 } 193 194 static int 195 get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value) 196 { 197 *value = hotplug_slot->info->adapter_status; 198 return 0; 199 } 200 201 static int 202 get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value) 203 { 204 *value = hotplug_slot->info->latch_status; 205 return 0; 206 } 207 208 static void release_slot(struct hotplug_slot *hotplug_slot) 209 { 210 struct slot *slot = hotplug_slot->private; 211 212 kfree(slot->hotplug_slot->info); 213 kfree(slot->hotplug_slot); 214 if (slot->dev) 215 pci_dev_put(slot->dev); 216 kfree(slot); 217 } 218 219 #define SLOT_NAME_SIZE 6 220 221 int 222 cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last) 223 { 224 struct slot *slot; 225 struct hotplug_slot *hotplug_slot; 226 struct hotplug_slot_info *info; 227 char name[SLOT_NAME_SIZE]; 228 int status; 229 int i; 230 231 if (!(controller && bus)) 232 return -ENODEV; 233 234 /* 235 * Create a structure for each slot, and register that slot 236 * with the pci_hotplug subsystem. 237 */ 238 for (i = first; i <= last; ++i) { 239 slot = kzalloc(sizeof (struct slot), GFP_KERNEL); 240 if (!slot) { 241 status = -ENOMEM; 242 goto error; 243 } 244 245 hotplug_slot = 246 kzalloc(sizeof (struct hotplug_slot), GFP_KERNEL); 247 if (!hotplug_slot) { 248 status = -ENOMEM; 249 goto error_slot; 250 } 251 slot->hotplug_slot = hotplug_slot; 252 253 info = kzalloc(sizeof (struct hotplug_slot_info), GFP_KERNEL); 254 if (!info) { 255 status = -ENOMEM; 256 goto error_hpslot; 257 } 258 hotplug_slot->info = info; 259 260 slot->bus = bus; 261 slot->number = i; 262 slot->devfn = PCI_DEVFN(i, 0); 263 264 snprintf(name, SLOT_NAME_SIZE, "%02x:%02x", bus->number, i); 265 266 hotplug_slot->private = slot; 267 hotplug_slot->release = &release_slot; 268 hotplug_slot->ops = &cpci_hotplug_slot_ops; 269 270 /* 271 * Initialize the slot info structure with some known 272 * good values. 273 */ 274 dbg("initializing slot %s", name); 275 info->power_status = cpci_get_power_status(slot); 276 info->attention_status = cpci_get_attention_status(slot); 277 278 dbg("registering slot %s", name); 279 status = pci_hp_register(slot->hotplug_slot, bus, i, name); 280 if (status) { 281 err("pci_hp_register failed with error %d", status); 282 goto error_info; 283 } 284 dbg("slot registered with name: %s", slot_name(slot)); 285 286 /* Add slot to our internal list */ 287 down_write(&list_rwsem); 288 list_add(&slot->slot_list, &slot_list); 289 slots++; 290 up_write(&list_rwsem); 291 } 292 return 0; 293 error_info: 294 kfree(info); 295 error_hpslot: 296 kfree(hotplug_slot); 297 error_slot: 298 kfree(slot); 299 error: 300 return status; 301 } 302 EXPORT_SYMBOL_GPL(cpci_hp_register_bus); 303 304 int 305 cpci_hp_unregister_bus(struct pci_bus *bus) 306 { 307 struct slot *slot; 308 struct slot *tmp; 309 int status = 0; 310 311 down_write(&list_rwsem); 312 if (!slots) { 313 up_write(&list_rwsem); 314 return -1; 315 } 316 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) { 317 if (slot->bus == bus) { 318 list_del(&slot->slot_list); 319 slots--; 320 321 dbg("deregistering slot %s", slot_name(slot)); 322 status = pci_hp_deregister(slot->hotplug_slot); 323 if (status) { 324 err("pci_hp_deregister failed with error %d", 325 status); 326 break; 327 } 328 } 329 } 330 up_write(&list_rwsem); 331 return status; 332 } 333 EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus); 334 335 /* This is the interrupt mode interrupt handler */ 336 static irqreturn_t 337 cpci_hp_intr(int irq, void *data) 338 { 339 dbg("entered cpci_hp_intr"); 340 341 /* Check to see if it was our interrupt */ 342 if ((controller->irq_flags & IRQF_SHARED) && 343 !controller->ops->check_irq(controller->dev_id)) { 344 dbg("exited cpci_hp_intr, not our interrupt"); 345 return IRQ_NONE; 346 } 347 348 /* Disable ENUM interrupt */ 349 controller->ops->disable_irq(); 350 351 /* Trigger processing by the event thread */ 352 wake_up_process(cpci_thread); 353 return IRQ_HANDLED; 354 } 355 356 /* 357 * According to PICMG 2.1 R2.0, section 6.3.2, upon 358 * initialization, the system driver shall clear the 359 * INS bits of the cold-inserted devices. 360 */ 361 static int 362 init_slots(int clear_ins) 363 { 364 struct slot *slot; 365 struct pci_dev *dev; 366 367 dbg("%s - enter", __func__); 368 down_read(&list_rwsem); 369 if (!slots) { 370 up_read(&list_rwsem); 371 return -1; 372 } 373 list_for_each_entry(slot, &slot_list, slot_list) { 374 dbg("%s - looking at slot %s", __func__, slot_name(slot)); 375 if (clear_ins && cpci_check_and_clear_ins(slot)) 376 dbg("%s - cleared INS for slot %s", 377 __func__, slot_name(slot)); 378 dev = pci_get_slot(slot->bus, PCI_DEVFN(slot->number, 0)); 379 if (dev) { 380 if (update_adapter_status(slot->hotplug_slot, 1)) 381 warn("failure to update adapter file"); 382 if (update_latch_status(slot->hotplug_slot, 1)) 383 warn("failure to update latch file"); 384 slot->dev = dev; 385 } 386 } 387 up_read(&list_rwsem); 388 dbg("%s - exit", __func__); 389 return 0; 390 } 391 392 static int 393 check_slots(void) 394 { 395 struct slot *slot; 396 int extracted; 397 int inserted; 398 u16 hs_csr; 399 400 down_read(&list_rwsem); 401 if (!slots) { 402 up_read(&list_rwsem); 403 err("no slots registered, shutting down"); 404 return -1; 405 } 406 extracted = inserted = 0; 407 list_for_each_entry(slot, &slot_list, slot_list) { 408 dbg("%s - looking at slot %s", __func__, slot_name(slot)); 409 if (cpci_check_and_clear_ins(slot)) { 410 /* 411 * Some broken hardware (e.g. PLX 9054AB) asserts 412 * ENUM# twice... 413 */ 414 if (slot->dev) { 415 warn("slot %s already inserted", 416 slot_name(slot)); 417 inserted++; 418 continue; 419 } 420 421 /* Process insertion */ 422 dbg("%s - slot %s inserted", __func__, slot_name(slot)); 423 424 /* GSM, debug */ 425 hs_csr = cpci_get_hs_csr(slot); 426 dbg("%s - slot %s HS_CSR (1) = %04x", 427 __func__, slot_name(slot), hs_csr); 428 429 /* Configure device */ 430 dbg("%s - configuring slot %s", 431 __func__, slot_name(slot)); 432 if (cpci_configure_slot(slot)) { 433 err("%s - could not configure slot %s", 434 __func__, slot_name(slot)); 435 continue; 436 } 437 dbg("%s - finished configuring slot %s", 438 __func__, slot_name(slot)); 439 440 /* GSM, debug */ 441 hs_csr = cpci_get_hs_csr(slot); 442 dbg("%s - slot %s HS_CSR (2) = %04x", 443 __func__, slot_name(slot), hs_csr); 444 445 if (update_latch_status(slot->hotplug_slot, 1)) 446 warn("failure to update latch file"); 447 448 if (update_adapter_status(slot->hotplug_slot, 1)) 449 warn("failure to update adapter file"); 450 451 cpci_led_off(slot); 452 453 /* GSM, debug */ 454 hs_csr = cpci_get_hs_csr(slot); 455 dbg("%s - slot %s HS_CSR (3) = %04x", 456 __func__, slot_name(slot), hs_csr); 457 458 inserted++; 459 } else if (cpci_check_ext(slot)) { 460 /* Process extraction request */ 461 dbg("%s - slot %s extracted", 462 __func__, slot_name(slot)); 463 464 /* GSM, debug */ 465 hs_csr = cpci_get_hs_csr(slot); 466 dbg("%s - slot %s HS_CSR = %04x", 467 __func__, slot_name(slot), hs_csr); 468 469 if (!slot->extracting) { 470 if (update_latch_status(slot->hotplug_slot, 0)) { 471 warn("failure to update latch file"); 472 } 473 slot->extracting = 1; 474 atomic_inc(&extracting); 475 } 476 extracted++; 477 } else if (slot->extracting) { 478 hs_csr = cpci_get_hs_csr(slot); 479 if (hs_csr == 0xffff) { 480 /* 481 * Hmmm, we're likely hosed at this point, should we 482 * bother trying to tell the driver or not? 483 */ 484 err("card in slot %s was improperly removed", 485 slot_name(slot)); 486 if (update_adapter_status(slot->hotplug_slot, 0)) 487 warn("failure to update adapter file"); 488 slot->extracting = 0; 489 atomic_dec(&extracting); 490 } 491 } 492 } 493 up_read(&list_rwsem); 494 dbg("inserted=%d, extracted=%d, extracting=%d", 495 inserted, extracted, atomic_read(&extracting)); 496 if (inserted || extracted) 497 return extracted; 498 else if (!atomic_read(&extracting)) { 499 err("cannot find ENUM# source, shutting down"); 500 return -1; 501 } 502 return 0; 503 } 504 505 /* This is the interrupt mode worker thread body */ 506 static int 507 event_thread(void *data) 508 { 509 int rc; 510 511 dbg("%s - event thread started", __func__); 512 while (1) { 513 dbg("event thread sleeping"); 514 set_current_state(TASK_INTERRUPTIBLE); 515 schedule(); 516 if (kthread_should_stop()) 517 break; 518 do { 519 rc = check_slots(); 520 if (rc > 0) { 521 /* Give userspace a chance to handle extraction */ 522 msleep(500); 523 } else if (rc < 0) { 524 dbg("%s - error checking slots", __func__); 525 thread_finished = 1; 526 goto out; 527 } 528 } while (atomic_read(&extracting) && !kthread_should_stop()); 529 if (kthread_should_stop()) 530 break; 531 532 /* Re-enable ENUM# interrupt */ 533 dbg("%s - re-enabling irq", __func__); 534 controller->ops->enable_irq(); 535 } 536 out: 537 return 0; 538 } 539 540 /* This is the polling mode worker thread body */ 541 static int 542 poll_thread(void *data) 543 { 544 int rc; 545 546 while (1) { 547 if (kthread_should_stop() || signal_pending(current)) 548 break; 549 if (controller->ops->query_enum()) { 550 do { 551 rc = check_slots(); 552 if (rc > 0) { 553 /* Give userspace a chance to handle extraction */ 554 msleep(500); 555 } else if (rc < 0) { 556 dbg("%s - error checking slots", __func__); 557 thread_finished = 1; 558 goto out; 559 } 560 } while (atomic_read(&extracting) && !kthread_should_stop()); 561 } 562 msleep(100); 563 } 564 out: 565 return 0; 566 } 567 568 static int 569 cpci_start_thread(void) 570 { 571 if (controller->irq) 572 cpci_thread = kthread_run(event_thread, NULL, "cpci_hp_eventd"); 573 else 574 cpci_thread = kthread_run(poll_thread, NULL, "cpci_hp_polld"); 575 if (IS_ERR(cpci_thread)) { 576 err("Can't start up our thread"); 577 return PTR_ERR(cpci_thread); 578 } 579 thread_finished = 0; 580 return 0; 581 } 582 583 static void 584 cpci_stop_thread(void) 585 { 586 kthread_stop(cpci_thread); 587 thread_finished = 1; 588 } 589 590 int 591 cpci_hp_register_controller(struct cpci_hp_controller *new_controller) 592 { 593 int status = 0; 594 595 if (controller) 596 return -1; 597 if (!(new_controller && new_controller->ops)) 598 return -EINVAL; 599 if (new_controller->irq) { 600 if (!(new_controller->ops->enable_irq && 601 new_controller->ops->disable_irq)) 602 status = -EINVAL; 603 if (request_irq(new_controller->irq, 604 cpci_hp_intr, 605 new_controller->irq_flags, 606 MY_NAME, 607 new_controller->dev_id)) { 608 err("Can't get irq %d for the hotplug cPCI controller", 609 new_controller->irq); 610 status = -ENODEV; 611 } 612 dbg("%s - acquired controller irq %d", 613 __func__, new_controller->irq); 614 } 615 if (!status) 616 controller = new_controller; 617 return status; 618 } 619 EXPORT_SYMBOL_GPL(cpci_hp_register_controller); 620 621 static void 622 cleanup_slots(void) 623 { 624 struct slot *slot; 625 struct slot *tmp; 626 627 /* 628 * Unregister all of our slots with the pci_hotplug subsystem, 629 * and free up all memory that we had allocated. 630 */ 631 down_write(&list_rwsem); 632 if (!slots) 633 goto cleanup_null; 634 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) { 635 list_del(&slot->slot_list); 636 pci_hp_deregister(slot->hotplug_slot); 637 } 638 cleanup_null: 639 up_write(&list_rwsem); 640 return; 641 } 642 643 int 644 cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller) 645 { 646 int status = 0; 647 648 if (controller) { 649 if (!thread_finished) 650 cpci_stop_thread(); 651 if (controller->irq) 652 free_irq(controller->irq, controller->dev_id); 653 controller = NULL; 654 cleanup_slots(); 655 } else 656 status = -ENODEV; 657 return status; 658 } 659 EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller); 660 661 int 662 cpci_hp_start(void) 663 { 664 static int first = 1; 665 int status; 666 667 dbg("%s - enter", __func__); 668 if (!controller) 669 return -ENODEV; 670 671 down_read(&list_rwsem); 672 if (list_empty(&slot_list)) { 673 up_read(&list_rwsem); 674 return -ENODEV; 675 } 676 up_read(&list_rwsem); 677 678 status = init_slots(first); 679 if (first) 680 first = 0; 681 if (status) 682 return status; 683 684 status = cpci_start_thread(); 685 if (status) 686 return status; 687 dbg("%s - thread started", __func__); 688 689 if (controller->irq) { 690 /* Start enum interrupt processing */ 691 dbg("%s - enabling irq", __func__); 692 controller->ops->enable_irq(); 693 } 694 dbg("%s - exit", __func__); 695 return 0; 696 } 697 EXPORT_SYMBOL_GPL(cpci_hp_start); 698 699 int 700 cpci_hp_stop(void) 701 { 702 if (!controller) 703 return -ENODEV; 704 if (controller->irq) { 705 /* Stop enum interrupt processing */ 706 dbg("%s - disabling irq", __func__); 707 controller->ops->disable_irq(); 708 } 709 cpci_stop_thread(); 710 return 0; 711 } 712 EXPORT_SYMBOL_GPL(cpci_hp_stop); 713 714 int __init 715 cpci_hotplug_init(int debug) 716 { 717 cpci_debug = debug; 718 return 0; 719 } 720 721 void __exit 722 cpci_hotplug_exit(void) 723 { 724 /* 725 * Clean everything up. 726 */ 727 cpci_hp_stop(); 728 cpci_hp_unregister_controller(controller); 729 } 730