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 } 302 303 int 304 cpci_hp_unregister_bus(struct pci_bus *bus) 305 { 306 struct slot *slot; 307 struct slot *tmp; 308 int status = 0; 309 310 down_write(&list_rwsem); 311 if (!slots) { 312 up_write(&list_rwsem); 313 return -1; 314 } 315 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) { 316 if (slot->bus == bus) { 317 list_del(&slot->slot_list); 318 slots--; 319 320 dbg("deregistering slot %s", slot_name(slot)); 321 status = pci_hp_deregister(slot->hotplug_slot); 322 if (status) { 323 err("pci_hp_deregister failed with error %d", 324 status); 325 break; 326 } 327 } 328 } 329 up_write(&list_rwsem); 330 return status; 331 } 332 333 /* This is the interrupt mode interrupt handler */ 334 static irqreturn_t 335 cpci_hp_intr(int irq, void *data) 336 { 337 dbg("entered cpci_hp_intr"); 338 339 /* Check to see if it was our interrupt */ 340 if ((controller->irq_flags & IRQF_SHARED) && 341 !controller->ops->check_irq(controller->dev_id)) { 342 dbg("exited cpci_hp_intr, not our interrupt"); 343 return IRQ_NONE; 344 } 345 346 /* Disable ENUM interrupt */ 347 controller->ops->disable_irq(); 348 349 /* Trigger processing by the event thread */ 350 wake_up_process(cpci_thread); 351 return IRQ_HANDLED; 352 } 353 354 /* 355 * According to PICMG 2.1 R2.0, section 6.3.2, upon 356 * initialization, the system driver shall clear the 357 * INS bits of the cold-inserted devices. 358 */ 359 static int 360 init_slots(int clear_ins) 361 { 362 struct slot *slot; 363 struct pci_dev* dev; 364 365 dbg("%s - enter", __func__); 366 down_read(&list_rwsem); 367 if (!slots) { 368 up_read(&list_rwsem); 369 return -1; 370 } 371 list_for_each_entry(slot, &slot_list, slot_list) { 372 dbg("%s - looking at slot %s", __func__, slot_name(slot)); 373 if (clear_ins && cpci_check_and_clear_ins(slot)) 374 dbg("%s - cleared INS for slot %s", 375 __func__, slot_name(slot)); 376 dev = pci_get_slot(slot->bus, PCI_DEVFN(slot->number, 0)); 377 if (dev) { 378 if (update_adapter_status(slot->hotplug_slot, 1)) 379 warn("failure to update adapter file"); 380 if (update_latch_status(slot->hotplug_slot, 1)) 381 warn("failure to update latch file"); 382 slot->dev = dev; 383 } 384 } 385 up_read(&list_rwsem); 386 dbg("%s - exit", __func__); 387 return 0; 388 } 389 390 static int 391 check_slots(void) 392 { 393 struct slot *slot; 394 int extracted; 395 int inserted; 396 u16 hs_csr; 397 398 down_read(&list_rwsem); 399 if (!slots) { 400 up_read(&list_rwsem); 401 err("no slots registered, shutting down"); 402 return -1; 403 } 404 extracted = inserted = 0; 405 list_for_each_entry(slot, &slot_list, slot_list) { 406 dbg("%s - looking at slot %s", __func__, slot_name(slot)); 407 if (cpci_check_and_clear_ins(slot)) { 408 /* 409 * Some broken hardware (e.g. PLX 9054AB) asserts 410 * ENUM# twice... 411 */ 412 if (slot->dev) { 413 warn("slot %s already inserted", 414 slot_name(slot)); 415 inserted++; 416 continue; 417 } 418 419 /* Process insertion */ 420 dbg("%s - slot %s inserted", __func__, slot_name(slot)); 421 422 /* GSM, debug */ 423 hs_csr = cpci_get_hs_csr(slot); 424 dbg("%s - slot %s HS_CSR (1) = %04x", 425 __func__, slot_name(slot), hs_csr); 426 427 /* Configure device */ 428 dbg("%s - configuring slot %s", 429 __func__, slot_name(slot)); 430 if (cpci_configure_slot(slot)) { 431 err("%s - could not configure slot %s", 432 __func__, slot_name(slot)); 433 continue; 434 } 435 dbg("%s - finished configuring slot %s", 436 __func__, slot_name(slot)); 437 438 /* GSM, debug */ 439 hs_csr = cpci_get_hs_csr(slot); 440 dbg("%s - slot %s HS_CSR (2) = %04x", 441 __func__, slot_name(slot), hs_csr); 442 443 if (update_latch_status(slot->hotplug_slot, 1)) 444 warn("failure to update latch file"); 445 446 if (update_adapter_status(slot->hotplug_slot, 1)) 447 warn("failure to update adapter file"); 448 449 cpci_led_off(slot); 450 451 /* GSM, debug */ 452 hs_csr = cpci_get_hs_csr(slot); 453 dbg("%s - slot %s HS_CSR (3) = %04x", 454 __func__, slot_name(slot), hs_csr); 455 456 inserted++; 457 } else if (cpci_check_ext(slot)) { 458 /* Process extraction request */ 459 dbg("%s - slot %s extracted", 460 __func__, slot_name(slot)); 461 462 /* GSM, debug */ 463 hs_csr = cpci_get_hs_csr(slot); 464 dbg("%s - slot %s HS_CSR = %04x", 465 __func__, slot_name(slot), hs_csr); 466 467 if (!slot->extracting) { 468 if (update_latch_status(slot->hotplug_slot, 0)) { 469 warn("failure to update latch file"); 470 } 471 slot->extracting = 1; 472 atomic_inc(&extracting); 473 } 474 extracted++; 475 } else if (slot->extracting) { 476 hs_csr = cpci_get_hs_csr(slot); 477 if (hs_csr == 0xffff) { 478 /* 479 * Hmmm, we're likely hosed at this point, should we 480 * bother trying to tell the driver or not? 481 */ 482 err("card in slot %s was improperly removed", 483 slot_name(slot)); 484 if (update_adapter_status(slot->hotplug_slot, 0)) 485 warn("failure to update adapter file"); 486 slot->extracting = 0; 487 atomic_dec(&extracting); 488 } 489 } 490 } 491 up_read(&list_rwsem); 492 dbg("inserted=%d, extracted=%d, extracting=%d", 493 inserted, extracted, atomic_read(&extracting)); 494 if (inserted || extracted) 495 return extracted; 496 else if (!atomic_read(&extracting)) { 497 err("cannot find ENUM# source, shutting down"); 498 return -1; 499 } 500 return 0; 501 } 502 503 /* This is the interrupt mode worker thread body */ 504 static int 505 event_thread(void *data) 506 { 507 int rc; 508 509 dbg("%s - event thread started", __func__); 510 while (1) { 511 dbg("event thread sleeping"); 512 set_current_state(TASK_INTERRUPTIBLE); 513 schedule(); 514 if (kthread_should_stop()) 515 break; 516 do { 517 rc = check_slots(); 518 if (rc > 0) { 519 /* Give userspace a chance to handle extraction */ 520 msleep(500); 521 } else if (rc < 0) { 522 dbg("%s - error checking slots", __func__); 523 thread_finished = 1; 524 goto out; 525 } 526 } while (atomic_read(&extracting) && !kthread_should_stop()); 527 if (kthread_should_stop()) 528 break; 529 530 /* Re-enable ENUM# interrupt */ 531 dbg("%s - re-enabling irq", __func__); 532 controller->ops->enable_irq(); 533 } 534 out: 535 return 0; 536 } 537 538 /* This is the polling mode worker thread body */ 539 static int 540 poll_thread(void *data) 541 { 542 int rc; 543 544 while (1) { 545 if (kthread_should_stop() || signal_pending(current)) 546 break; 547 if (controller->ops->query_enum()) { 548 do { 549 rc = check_slots(); 550 if (rc > 0) { 551 /* Give userspace a chance to handle extraction */ 552 msleep(500); 553 } else if (rc < 0) { 554 dbg("%s - error checking slots", __func__); 555 thread_finished = 1; 556 goto out; 557 } 558 } while (atomic_read(&extracting) && !kthread_should_stop()); 559 } 560 msleep(100); 561 } 562 out: 563 return 0; 564 } 565 566 static int 567 cpci_start_thread(void) 568 { 569 if (controller->irq) 570 cpci_thread = kthread_run(event_thread, NULL, "cpci_hp_eventd"); 571 else 572 cpci_thread = kthread_run(poll_thread, NULL, "cpci_hp_polld"); 573 if (IS_ERR(cpci_thread)) { 574 err("Can't start up our thread"); 575 return PTR_ERR(cpci_thread); 576 } 577 thread_finished = 0; 578 return 0; 579 } 580 581 static void 582 cpci_stop_thread(void) 583 { 584 kthread_stop(cpci_thread); 585 thread_finished = 1; 586 } 587 588 int 589 cpci_hp_register_controller(struct cpci_hp_controller *new_controller) 590 { 591 int status = 0; 592 593 if (controller) 594 return -1; 595 if (!(new_controller && new_controller->ops)) 596 return -EINVAL; 597 if (new_controller->irq) { 598 if (!(new_controller->ops->enable_irq && 599 new_controller->ops->disable_irq)) 600 status = -EINVAL; 601 if (request_irq(new_controller->irq, 602 cpci_hp_intr, 603 new_controller->irq_flags, 604 MY_NAME, 605 new_controller->dev_id)) { 606 err("Can't get irq %d for the hotplug cPCI controller", 607 new_controller->irq); 608 status = -ENODEV; 609 } 610 dbg("%s - acquired controller irq %d", 611 __func__, new_controller->irq); 612 } 613 if (!status) 614 controller = new_controller; 615 return status; 616 } 617 618 static void 619 cleanup_slots(void) 620 { 621 struct slot *slot; 622 struct slot *tmp; 623 624 /* 625 * Unregister all of our slots with the pci_hotplug subsystem, 626 * and free up all memory that we had allocated. 627 */ 628 down_write(&list_rwsem); 629 if (!slots) 630 goto cleanup_null; 631 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) { 632 list_del(&slot->slot_list); 633 pci_hp_deregister(slot->hotplug_slot); 634 } 635 cleanup_null: 636 up_write(&list_rwsem); 637 return; 638 } 639 640 int 641 cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller) 642 { 643 int status = 0; 644 645 if (controller) { 646 if (!thread_finished) 647 cpci_stop_thread(); 648 if (controller->irq) 649 free_irq(controller->irq, controller->dev_id); 650 controller = NULL; 651 cleanup_slots(); 652 } else 653 status = -ENODEV; 654 return status; 655 } 656 657 int 658 cpci_hp_start(void) 659 { 660 static int first = 1; 661 int status; 662 663 dbg("%s - enter", __func__); 664 if (!controller) 665 return -ENODEV; 666 667 down_read(&list_rwsem); 668 if (list_empty(&slot_list)) { 669 up_read(&list_rwsem); 670 return -ENODEV; 671 } 672 up_read(&list_rwsem); 673 674 status = init_slots(first); 675 if (first) 676 first = 0; 677 if (status) 678 return status; 679 680 status = cpci_start_thread(); 681 if (status) 682 return status; 683 dbg("%s - thread started", __func__); 684 685 if (controller->irq) { 686 /* Start enum interrupt processing */ 687 dbg("%s - enabling irq", __func__); 688 controller->ops->enable_irq(); 689 } 690 dbg("%s - exit", __func__); 691 return 0; 692 } 693 694 int 695 cpci_hp_stop(void) 696 { 697 if (!controller) 698 return -ENODEV; 699 if (controller->irq) { 700 /* Stop enum interrupt processing */ 701 dbg("%s - disabling irq", __func__); 702 controller->ops->disable_irq(); 703 } 704 cpci_stop_thread(); 705 return 0; 706 } 707 708 int __init 709 cpci_hotplug_init(int debug) 710 { 711 cpci_debug = debug; 712 return 0; 713 } 714 715 void __exit 716 cpci_hotplug_exit(void) 717 { 718 /* 719 * Clean everything up. 720 */ 721 cpci_hp_stop(); 722 cpci_hp_unregister_controller(controller); 723 } 724 725 EXPORT_SYMBOL_GPL(cpci_hp_register_controller); 726 EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller); 727 EXPORT_SYMBOL_GPL(cpci_hp_register_bus); 728 EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus); 729 EXPORT_SYMBOL_GPL(cpci_hp_start); 730 EXPORT_SYMBOL_GPL(cpci_hp_stop); 731