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 <asm/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 = -ENOMEM; 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 goto error; 242 243 hotplug_slot = 244 kzalloc(sizeof (struct hotplug_slot), GFP_KERNEL); 245 if (!hotplug_slot) 246 goto error_slot; 247 slot->hotplug_slot = hotplug_slot; 248 249 info = kzalloc(sizeof (struct hotplug_slot_info), GFP_KERNEL); 250 if (!info) 251 goto error_hpslot; 252 hotplug_slot->info = info; 253 254 slot->bus = bus; 255 slot->number = i; 256 slot->devfn = PCI_DEVFN(i, 0); 257 258 snprintf(name, SLOT_NAME_SIZE, "%02x:%02x", bus->number, i); 259 260 hotplug_slot->private = slot; 261 hotplug_slot->release = &release_slot; 262 hotplug_slot->ops = &cpci_hotplug_slot_ops; 263 264 /* 265 * Initialize the slot info structure with some known 266 * good values. 267 */ 268 dbg("initializing slot %s", name); 269 info->power_status = cpci_get_power_status(slot); 270 info->attention_status = cpci_get_attention_status(slot); 271 272 dbg("registering slot %s", name); 273 status = pci_hp_register(slot->hotplug_slot, bus, i, name); 274 if (status) { 275 err("pci_hp_register failed with error %d", status); 276 goto error_info; 277 } 278 dbg("slot registered with name: %s", slot_name(slot)); 279 280 /* Add slot to our internal list */ 281 down_write(&list_rwsem); 282 list_add(&slot->slot_list, &slot_list); 283 slots++; 284 up_write(&list_rwsem); 285 } 286 return 0; 287 error_info: 288 kfree(info); 289 error_hpslot: 290 kfree(hotplug_slot); 291 error_slot: 292 kfree(slot); 293 error: 294 return status; 295 } 296 297 int 298 cpci_hp_unregister_bus(struct pci_bus *bus) 299 { 300 struct slot *slot; 301 struct slot *tmp; 302 int status = 0; 303 304 down_write(&list_rwsem); 305 if (!slots) { 306 up_write(&list_rwsem); 307 return -1; 308 } 309 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) { 310 if (slot->bus == bus) { 311 list_del(&slot->slot_list); 312 slots--; 313 314 dbg("deregistering slot %s", slot_name(slot)); 315 status = pci_hp_deregister(slot->hotplug_slot); 316 if (status) { 317 err("pci_hp_deregister failed with error %d", 318 status); 319 break; 320 } 321 } 322 } 323 up_write(&list_rwsem); 324 return status; 325 } 326 327 /* This is the interrupt mode interrupt handler */ 328 static irqreturn_t 329 cpci_hp_intr(int irq, void *data) 330 { 331 dbg("entered cpci_hp_intr"); 332 333 /* Check to see if it was our interrupt */ 334 if ((controller->irq_flags & IRQF_SHARED) && 335 !controller->ops->check_irq(controller->dev_id)) { 336 dbg("exited cpci_hp_intr, not our interrupt"); 337 return IRQ_NONE; 338 } 339 340 /* Disable ENUM interrupt */ 341 controller->ops->disable_irq(); 342 343 /* Trigger processing by the event thread */ 344 wake_up_process(cpci_thread); 345 return IRQ_HANDLED; 346 } 347 348 /* 349 * According to PICMG 2.1 R2.0, section 6.3.2, upon 350 * initialization, the system driver shall clear the 351 * INS bits of the cold-inserted devices. 352 */ 353 static int 354 init_slots(int clear_ins) 355 { 356 struct slot *slot; 357 struct pci_dev* dev; 358 359 dbg("%s - enter", __func__); 360 down_read(&list_rwsem); 361 if (!slots) { 362 up_read(&list_rwsem); 363 return -1; 364 } 365 list_for_each_entry(slot, &slot_list, slot_list) { 366 dbg("%s - looking at slot %s", __func__, slot_name(slot)); 367 if (clear_ins && cpci_check_and_clear_ins(slot)) 368 dbg("%s - cleared INS for slot %s", 369 __func__, slot_name(slot)); 370 dev = pci_get_slot(slot->bus, PCI_DEVFN(slot->number, 0)); 371 if (dev) { 372 if (update_adapter_status(slot->hotplug_slot, 1)) 373 warn("failure to update adapter file"); 374 if (update_latch_status(slot->hotplug_slot, 1)) 375 warn("failure to update latch file"); 376 slot->dev = dev; 377 } 378 } 379 up_read(&list_rwsem); 380 dbg("%s - exit", __func__); 381 return 0; 382 } 383 384 static int 385 check_slots(void) 386 { 387 struct slot *slot; 388 int extracted; 389 int inserted; 390 u16 hs_csr; 391 392 down_read(&list_rwsem); 393 if (!slots) { 394 up_read(&list_rwsem); 395 err("no slots registered, shutting down"); 396 return -1; 397 } 398 extracted = inserted = 0; 399 list_for_each_entry(slot, &slot_list, slot_list) { 400 dbg("%s - looking at slot %s", __func__, slot_name(slot)); 401 if (cpci_check_and_clear_ins(slot)) { 402 /* 403 * Some broken hardware (e.g. PLX 9054AB) asserts 404 * ENUM# twice... 405 */ 406 if (slot->dev) { 407 warn("slot %s already inserted", 408 slot_name(slot)); 409 inserted++; 410 continue; 411 } 412 413 /* Process insertion */ 414 dbg("%s - slot %s inserted", __func__, slot_name(slot)); 415 416 /* GSM, debug */ 417 hs_csr = cpci_get_hs_csr(slot); 418 dbg("%s - slot %s HS_CSR (1) = %04x", 419 __func__, slot_name(slot), hs_csr); 420 421 /* Configure device */ 422 dbg("%s - configuring slot %s", 423 __func__, slot_name(slot)); 424 if (cpci_configure_slot(slot)) { 425 err("%s - could not configure slot %s", 426 __func__, slot_name(slot)); 427 continue; 428 } 429 dbg("%s - finished configuring slot %s", 430 __func__, slot_name(slot)); 431 432 /* GSM, debug */ 433 hs_csr = cpci_get_hs_csr(slot); 434 dbg("%s - slot %s HS_CSR (2) = %04x", 435 __func__, slot_name(slot), hs_csr); 436 437 if (update_latch_status(slot->hotplug_slot, 1)) 438 warn("failure to update latch file"); 439 440 if (update_adapter_status(slot->hotplug_slot, 1)) 441 warn("failure to update adapter file"); 442 443 cpci_led_off(slot); 444 445 /* GSM, debug */ 446 hs_csr = cpci_get_hs_csr(slot); 447 dbg("%s - slot %s HS_CSR (3) = %04x", 448 __func__, slot_name(slot), hs_csr); 449 450 inserted++; 451 } else if (cpci_check_ext(slot)) { 452 /* Process extraction request */ 453 dbg("%s - slot %s extracted", 454 __func__, slot_name(slot)); 455 456 /* GSM, debug */ 457 hs_csr = cpci_get_hs_csr(slot); 458 dbg("%s - slot %s HS_CSR = %04x", 459 __func__, slot_name(slot), hs_csr); 460 461 if (!slot->extracting) { 462 if (update_latch_status(slot->hotplug_slot, 0)) { 463 warn("failure to update latch file"); 464 } 465 slot->extracting = 1; 466 atomic_inc(&extracting); 467 } 468 extracted++; 469 } else if (slot->extracting) { 470 hs_csr = cpci_get_hs_csr(slot); 471 if (hs_csr == 0xffff) { 472 /* 473 * Hmmm, we're likely hosed at this point, should we 474 * bother trying to tell the driver or not? 475 */ 476 err("card in slot %s was improperly removed", 477 slot_name(slot)); 478 if (update_adapter_status(slot->hotplug_slot, 0)) 479 warn("failure to update adapter file"); 480 slot->extracting = 0; 481 atomic_dec(&extracting); 482 } 483 } 484 } 485 up_read(&list_rwsem); 486 dbg("inserted=%d, extracted=%d, extracting=%d", 487 inserted, extracted, atomic_read(&extracting)); 488 if (inserted || extracted) 489 return extracted; 490 else if (!atomic_read(&extracting)) { 491 err("cannot find ENUM# source, shutting down"); 492 return -1; 493 } 494 return 0; 495 } 496 497 /* This is the interrupt mode worker thread body */ 498 static int 499 event_thread(void *data) 500 { 501 int rc; 502 503 dbg("%s - event thread started", __func__); 504 while (1) { 505 dbg("event thread sleeping"); 506 set_current_state(TASK_INTERRUPTIBLE); 507 schedule(); 508 if (kthread_should_stop()) 509 break; 510 do { 511 rc = check_slots(); 512 if (rc > 0) { 513 /* Give userspace a chance to handle extraction */ 514 msleep(500); 515 } else if (rc < 0) { 516 dbg("%s - error checking slots", __func__); 517 thread_finished = 1; 518 goto out; 519 } 520 } while (atomic_read(&extracting) && !kthread_should_stop()); 521 if (kthread_should_stop()) 522 break; 523 524 /* Re-enable ENUM# interrupt */ 525 dbg("%s - re-enabling irq", __func__); 526 controller->ops->enable_irq(); 527 } 528 out: 529 return 0; 530 } 531 532 /* This is the polling mode worker thread body */ 533 static int 534 poll_thread(void *data) 535 { 536 int rc; 537 538 while (1) { 539 if (kthread_should_stop() || signal_pending(current)) 540 break; 541 if (controller->ops->query_enum()) { 542 do { 543 rc = check_slots(); 544 if (rc > 0) { 545 /* Give userspace a chance to handle extraction */ 546 msleep(500); 547 } else if (rc < 0) { 548 dbg("%s - error checking slots", __func__); 549 thread_finished = 1; 550 goto out; 551 } 552 } while (atomic_read(&extracting) && !kthread_should_stop()); 553 } 554 msleep(100); 555 } 556 out: 557 return 0; 558 } 559 560 static int 561 cpci_start_thread(void) 562 { 563 if (controller->irq) 564 cpci_thread = kthread_run(event_thread, NULL, "cpci_hp_eventd"); 565 else 566 cpci_thread = kthread_run(poll_thread, NULL, "cpci_hp_polld"); 567 if (IS_ERR(cpci_thread)) { 568 err("Can't start up our thread"); 569 return PTR_ERR(cpci_thread); 570 } 571 thread_finished = 0; 572 return 0; 573 } 574 575 static void 576 cpci_stop_thread(void) 577 { 578 kthread_stop(cpci_thread); 579 thread_finished = 1; 580 } 581 582 int 583 cpci_hp_register_controller(struct cpci_hp_controller *new_controller) 584 { 585 int status = 0; 586 587 if (controller) 588 return -1; 589 if (!(new_controller && new_controller->ops)) 590 return -EINVAL; 591 if (new_controller->irq) { 592 if (!(new_controller->ops->enable_irq && 593 new_controller->ops->disable_irq)) 594 status = -EINVAL; 595 if (request_irq(new_controller->irq, 596 cpci_hp_intr, 597 new_controller->irq_flags, 598 MY_NAME, 599 new_controller->dev_id)) { 600 err("Can't get irq %d for the hotplug cPCI controller", 601 new_controller->irq); 602 status = -ENODEV; 603 } 604 dbg("%s - acquired controller irq %d", 605 __func__, new_controller->irq); 606 } 607 if (!status) 608 controller = new_controller; 609 return status; 610 } 611 612 static void 613 cleanup_slots(void) 614 { 615 struct slot *slot; 616 struct slot *tmp; 617 618 /* 619 * Unregister all of our slots with the pci_hotplug subsystem, 620 * and free up all memory that we had allocated. 621 */ 622 down_write(&list_rwsem); 623 if (!slots) 624 goto cleanup_null; 625 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) { 626 list_del(&slot->slot_list); 627 pci_hp_deregister(slot->hotplug_slot); 628 } 629 cleanup_null: 630 up_write(&list_rwsem); 631 return; 632 } 633 634 int 635 cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller) 636 { 637 int status = 0; 638 639 if (controller) { 640 if (!thread_finished) 641 cpci_stop_thread(); 642 if (controller->irq) 643 free_irq(controller->irq, controller->dev_id); 644 controller = NULL; 645 cleanup_slots(); 646 } else 647 status = -ENODEV; 648 return status; 649 } 650 651 int 652 cpci_hp_start(void) 653 { 654 static int first = 1; 655 int status; 656 657 dbg("%s - enter", __func__); 658 if (!controller) 659 return -ENODEV; 660 661 down_read(&list_rwsem); 662 if (list_empty(&slot_list)) { 663 up_read(&list_rwsem); 664 return -ENODEV; 665 } 666 up_read(&list_rwsem); 667 668 status = init_slots(first); 669 if (first) 670 first = 0; 671 if (status) 672 return status; 673 674 status = cpci_start_thread(); 675 if (status) 676 return status; 677 dbg("%s - thread started", __func__); 678 679 if (controller->irq) { 680 /* Start enum interrupt processing */ 681 dbg("%s - enabling irq", __func__); 682 controller->ops->enable_irq(); 683 } 684 dbg("%s - exit", __func__); 685 return 0; 686 } 687 688 int 689 cpci_hp_stop(void) 690 { 691 if (!controller) 692 return -ENODEV; 693 if (controller->irq) { 694 /* Stop enum interrupt processing */ 695 dbg("%s - disabling irq", __func__); 696 controller->ops->disable_irq(); 697 } 698 cpci_stop_thread(); 699 return 0; 700 } 701 702 int __init 703 cpci_hotplug_init(int debug) 704 { 705 cpci_debug = debug; 706 return 0; 707 } 708 709 void __exit 710 cpci_hotplug_exit(void) 711 { 712 /* 713 * Clean everything up. 714 */ 715 cpci_hp_stop(); 716 cpci_hp_unregister_controller(controller); 717 } 718 719 EXPORT_SYMBOL_GPL(cpci_hp_register_controller); 720 EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller); 721 EXPORT_SYMBOL_GPL(cpci_hp_register_bus); 722 EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus); 723 EXPORT_SYMBOL_GPL(cpci_hp_start); 724 EXPORT_SYMBOL_GPL(cpci_hp_stop); 725