1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * CompactPCI Hot Plug Driver 4 * 5 * Copyright (C) 2002,2005 SOMA Networks, Inc. 6 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com) 7 * Copyright (C) 2001 IBM Corp. 8 * 9 * All rights reserved. 10 * 11 * Send feedback to <scottm@somanetworks.com> 12 */ 13 14 #include <linux/module.h> 15 #include <linux/kernel.h> 16 #include <linux/sched/signal.h> 17 #include <linux/slab.h> 18 #include <linux/pci.h> 19 #include <linux/pci_hotplug.h> 20 #include <linux/init.h> 21 #include <linux/interrupt.h> 22 #include <linux/atomic.h> 23 #include <linux/delay.h> 24 #include <linux/kthread.h> 25 #include "cpci_hotplug.h" 26 27 #define DRIVER_AUTHOR "Scott Murray <scottm@somanetworks.com>" 28 #define DRIVER_DESC "CompactPCI Hot Plug Core" 29 30 #define MY_NAME "cpci_hotplug" 31 32 #define dbg(format, arg...) \ 33 do { \ 34 if (cpci_debug) \ 35 printk(KERN_DEBUG "%s: " format "\n", \ 36 MY_NAME, ## arg); \ 37 } while (0) 38 #define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg) 39 #define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg) 40 #define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg) 41 42 /* local variables */ 43 static DECLARE_RWSEM(list_rwsem); 44 static LIST_HEAD(slot_list); 45 static int slots; 46 static atomic_t extracting; 47 int cpci_debug; 48 static struct cpci_hp_controller *controller; 49 static struct task_struct *cpci_thread; 50 static int thread_finished; 51 52 static int enable_slot(struct hotplug_slot *slot); 53 static int disable_slot(struct hotplug_slot *slot); 54 static int set_attention_status(struct hotplug_slot *slot, u8 value); 55 static int get_power_status(struct hotplug_slot *slot, u8 *value); 56 static int get_attention_status(struct hotplug_slot *slot, u8 *value); 57 static int get_adapter_status(struct hotplug_slot *slot, u8 *value); 58 static int get_latch_status(struct hotplug_slot *slot, u8 *value); 59 60 static const struct hotplug_slot_ops cpci_hotplug_slot_ops = { 61 .enable_slot = enable_slot, 62 .disable_slot = disable_slot, 63 .set_attention_status = set_attention_status, 64 .get_power_status = get_power_status, 65 .get_attention_status = get_attention_status, 66 .get_adapter_status = get_adapter_status, 67 .get_latch_status = get_latch_status, 68 }; 69 70 static int 71 enable_slot(struct hotplug_slot *hotplug_slot) 72 { 73 struct slot *slot = to_slot(hotplug_slot); 74 int retval = 0; 75 76 dbg("%s - physical_slot = %s", __func__, slot_name(slot)); 77 78 if (controller->ops->set_power) 79 retval = controller->ops->set_power(slot, 1); 80 return retval; 81 } 82 83 static int 84 disable_slot(struct hotplug_slot *hotplug_slot) 85 { 86 struct slot *slot = to_slot(hotplug_slot); 87 int retval = 0; 88 89 dbg("%s - physical_slot = %s", __func__, slot_name(slot)); 90 91 down_write(&list_rwsem); 92 93 /* Unconfigure device */ 94 dbg("%s - unconfiguring slot %s", __func__, slot_name(slot)); 95 retval = cpci_unconfigure_slot(slot); 96 if (retval) { 97 err("%s - could not unconfigure slot %s", 98 __func__, slot_name(slot)); 99 goto disable_error; 100 } 101 dbg("%s - finished unconfiguring slot %s", __func__, slot_name(slot)); 102 103 /* Clear EXT (by setting it) */ 104 if (cpci_clear_ext(slot)) { 105 err("%s - could not clear EXT for slot %s", 106 __func__, slot_name(slot)); 107 retval = -ENODEV; 108 goto disable_error; 109 } 110 cpci_led_on(slot); 111 112 if (controller->ops->set_power) { 113 retval = controller->ops->set_power(slot, 0); 114 if (retval) 115 goto disable_error; 116 } 117 118 slot->adapter_status = 0; 119 120 if (slot->extracting) { 121 slot->extracting = 0; 122 atomic_dec(&extracting); 123 } 124 disable_error: 125 up_write(&list_rwsem); 126 return retval; 127 } 128 129 static u8 130 cpci_get_power_status(struct slot *slot) 131 { 132 u8 power = 1; 133 134 if (controller->ops->get_power) 135 power = controller->ops->get_power(slot); 136 return power; 137 } 138 139 static int 140 get_power_status(struct hotplug_slot *hotplug_slot, u8 *value) 141 { 142 struct slot *slot = to_slot(hotplug_slot); 143 144 *value = cpci_get_power_status(slot); 145 return 0; 146 } 147 148 static int 149 get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value) 150 { 151 struct slot *slot = to_slot(hotplug_slot); 152 153 *value = cpci_get_attention_status(slot); 154 return 0; 155 } 156 157 static int 158 set_attention_status(struct hotplug_slot *hotplug_slot, u8 status) 159 { 160 return cpci_set_attention_status(to_slot(hotplug_slot), status); 161 } 162 163 static int 164 get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value) 165 { 166 struct slot *slot = to_slot(hotplug_slot); 167 168 *value = slot->adapter_status; 169 return 0; 170 } 171 172 static int 173 get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value) 174 { 175 struct slot *slot = to_slot(hotplug_slot); 176 177 *value = slot->latch_status; 178 return 0; 179 } 180 181 static void release_slot(struct slot *slot) 182 { 183 pci_dev_put(slot->dev); 184 kfree(slot); 185 } 186 187 #define SLOT_NAME_SIZE 6 188 189 int 190 cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last) 191 { 192 struct slot *slot; 193 char name[SLOT_NAME_SIZE]; 194 int status; 195 int i; 196 197 if (!(controller && bus)) 198 return -ENODEV; 199 200 /* 201 * Create a structure for each slot, and register that slot 202 * with the pci_hotplug subsystem. 203 */ 204 for (i = first; i <= last; ++i) { 205 slot = kzalloc(sizeof(struct slot), GFP_KERNEL); 206 if (!slot) { 207 status = -ENOMEM; 208 goto error; 209 } 210 211 slot->bus = bus; 212 slot->number = i; 213 slot->devfn = PCI_DEVFN(i, 0); 214 215 snprintf(name, SLOT_NAME_SIZE, "%02x:%02x", bus->number, i); 216 217 slot->hotplug_slot.ops = &cpci_hotplug_slot_ops; 218 219 dbg("registering slot %s", name); 220 status = pci_hp_register(&slot->hotplug_slot, bus, i, name); 221 if (status) { 222 err("pci_hp_register failed with error %d", status); 223 goto error_slot; 224 } 225 dbg("slot registered with name: %s", slot_name(slot)); 226 227 /* Add slot to our internal list */ 228 down_write(&list_rwsem); 229 list_add(&slot->slot_list, &slot_list); 230 slots++; 231 up_write(&list_rwsem); 232 } 233 return 0; 234 error_slot: 235 kfree(slot); 236 error: 237 return status; 238 } 239 EXPORT_SYMBOL_GPL(cpci_hp_register_bus); 240 241 int 242 cpci_hp_unregister_bus(struct pci_bus *bus) 243 { 244 struct slot *slot; 245 struct slot *tmp; 246 int status = 0; 247 248 down_write(&list_rwsem); 249 if (!slots) { 250 up_write(&list_rwsem); 251 return -1; 252 } 253 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) { 254 if (slot->bus == bus) { 255 list_del(&slot->slot_list); 256 slots--; 257 258 dbg("deregistering slot %s", slot_name(slot)); 259 pci_hp_deregister(&slot->hotplug_slot); 260 release_slot(slot); 261 } 262 } 263 up_write(&list_rwsem); 264 return status; 265 } 266 EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus); 267 268 /* This is the interrupt mode interrupt handler */ 269 static irqreturn_t 270 cpci_hp_intr(int irq, void *data) 271 { 272 dbg("entered cpci_hp_intr"); 273 274 /* Check to see if it was our interrupt */ 275 if ((controller->irq_flags & IRQF_SHARED) && 276 !controller->ops->check_irq(controller->dev_id)) { 277 dbg("exited cpci_hp_intr, not our interrupt"); 278 return IRQ_NONE; 279 } 280 281 /* Disable ENUM interrupt */ 282 controller->ops->disable_irq(); 283 284 /* Trigger processing by the event thread */ 285 wake_up_process(cpci_thread); 286 return IRQ_HANDLED; 287 } 288 289 /* 290 * According to PICMG 2.1 R2.0, section 6.3.2, upon 291 * initialization, the system driver shall clear the 292 * INS bits of the cold-inserted devices. 293 */ 294 static int 295 init_slots(int clear_ins) 296 { 297 struct slot *slot; 298 struct pci_dev *dev; 299 300 dbg("%s - enter", __func__); 301 down_read(&list_rwsem); 302 if (!slots) { 303 up_read(&list_rwsem); 304 return -1; 305 } 306 list_for_each_entry(slot, &slot_list, slot_list) { 307 dbg("%s - looking at slot %s", __func__, slot_name(slot)); 308 if (clear_ins && cpci_check_and_clear_ins(slot)) 309 dbg("%s - cleared INS for slot %s", 310 __func__, slot_name(slot)); 311 dev = pci_get_slot(slot->bus, PCI_DEVFN(slot->number, 0)); 312 if (dev) { 313 slot->adapter_status = 1; 314 slot->latch_status = 1; 315 slot->dev = dev; 316 } 317 } 318 up_read(&list_rwsem); 319 dbg("%s - exit", __func__); 320 return 0; 321 } 322 323 static int 324 check_slots(void) 325 { 326 struct slot *slot; 327 int extracted; 328 int inserted; 329 u16 hs_csr; 330 331 down_read(&list_rwsem); 332 if (!slots) { 333 up_read(&list_rwsem); 334 err("no slots registered, shutting down"); 335 return -1; 336 } 337 extracted = inserted = 0; 338 list_for_each_entry(slot, &slot_list, slot_list) { 339 dbg("%s - looking at slot %s", __func__, slot_name(slot)); 340 if (cpci_check_and_clear_ins(slot)) { 341 /* 342 * Some broken hardware (e.g. PLX 9054AB) asserts 343 * ENUM# twice... 344 */ 345 if (slot->dev) { 346 warn("slot %s already inserted", 347 slot_name(slot)); 348 inserted++; 349 continue; 350 } 351 352 /* Process insertion */ 353 dbg("%s - slot %s inserted", __func__, slot_name(slot)); 354 355 /* GSM, debug */ 356 hs_csr = cpci_get_hs_csr(slot); 357 dbg("%s - slot %s HS_CSR (1) = %04x", 358 __func__, slot_name(slot), hs_csr); 359 360 /* Configure device */ 361 dbg("%s - configuring slot %s", 362 __func__, slot_name(slot)); 363 if (cpci_configure_slot(slot)) { 364 err("%s - could not configure slot %s", 365 __func__, slot_name(slot)); 366 continue; 367 } 368 dbg("%s - finished configuring slot %s", 369 __func__, slot_name(slot)); 370 371 /* GSM, debug */ 372 hs_csr = cpci_get_hs_csr(slot); 373 dbg("%s - slot %s HS_CSR (2) = %04x", 374 __func__, slot_name(slot), hs_csr); 375 376 slot->latch_status = 1; 377 slot->adapter_status = 1; 378 379 cpci_led_off(slot); 380 381 /* GSM, debug */ 382 hs_csr = cpci_get_hs_csr(slot); 383 dbg("%s - slot %s HS_CSR (3) = %04x", 384 __func__, slot_name(slot), hs_csr); 385 386 inserted++; 387 } else if (cpci_check_ext(slot)) { 388 /* Process extraction request */ 389 dbg("%s - slot %s extracted", 390 __func__, slot_name(slot)); 391 392 /* GSM, debug */ 393 hs_csr = cpci_get_hs_csr(slot); 394 dbg("%s - slot %s HS_CSR = %04x", 395 __func__, slot_name(slot), hs_csr); 396 397 if (!slot->extracting) { 398 slot->latch_status = 0; 399 slot->extracting = 1; 400 atomic_inc(&extracting); 401 } 402 extracted++; 403 } else if (slot->extracting) { 404 hs_csr = cpci_get_hs_csr(slot); 405 if (hs_csr == 0xffff) { 406 /* 407 * Hmmm, we're likely hosed at this point, should we 408 * bother trying to tell the driver or not? 409 */ 410 err("card in slot %s was improperly removed", 411 slot_name(slot)); 412 slot->adapter_status = 0; 413 slot->extracting = 0; 414 atomic_dec(&extracting); 415 } 416 } 417 } 418 up_read(&list_rwsem); 419 dbg("inserted=%d, extracted=%d, extracting=%d", 420 inserted, extracted, atomic_read(&extracting)); 421 if (inserted || extracted) 422 return extracted; 423 else if (!atomic_read(&extracting)) { 424 err("cannot find ENUM# source, shutting down"); 425 return -1; 426 } 427 return 0; 428 } 429 430 /* This is the interrupt mode worker thread body */ 431 static int 432 event_thread(void *data) 433 { 434 int rc; 435 436 dbg("%s - event thread started", __func__); 437 while (1) { 438 dbg("event thread sleeping"); 439 set_current_state(TASK_INTERRUPTIBLE); 440 schedule(); 441 if (kthread_should_stop()) 442 break; 443 do { 444 rc = check_slots(); 445 if (rc > 0) { 446 /* Give userspace a chance to handle extraction */ 447 msleep(500); 448 } else if (rc < 0) { 449 dbg("%s - error checking slots", __func__); 450 thread_finished = 1; 451 goto out; 452 } 453 } while (atomic_read(&extracting) && !kthread_should_stop()); 454 if (kthread_should_stop()) 455 break; 456 457 /* Re-enable ENUM# interrupt */ 458 dbg("%s - re-enabling irq", __func__); 459 controller->ops->enable_irq(); 460 } 461 out: 462 return 0; 463 } 464 465 /* This is the polling mode worker thread body */ 466 static int 467 poll_thread(void *data) 468 { 469 int rc; 470 471 while (1) { 472 if (kthread_should_stop() || signal_pending(current)) 473 break; 474 if (controller->ops->query_enum()) { 475 do { 476 rc = check_slots(); 477 if (rc > 0) { 478 /* Give userspace a chance to handle extraction */ 479 msleep(500); 480 } else if (rc < 0) { 481 dbg("%s - error checking slots", __func__); 482 thread_finished = 1; 483 goto out; 484 } 485 } while (atomic_read(&extracting) && !kthread_should_stop()); 486 } 487 msleep(100); 488 } 489 out: 490 return 0; 491 } 492 493 static int 494 cpci_start_thread(void) 495 { 496 if (controller->irq) 497 cpci_thread = kthread_run(event_thread, NULL, "cpci_hp_eventd"); 498 else 499 cpci_thread = kthread_run(poll_thread, NULL, "cpci_hp_polld"); 500 if (IS_ERR(cpci_thread)) { 501 err("Can't start up our thread"); 502 return PTR_ERR(cpci_thread); 503 } 504 thread_finished = 0; 505 return 0; 506 } 507 508 static void 509 cpci_stop_thread(void) 510 { 511 kthread_stop(cpci_thread); 512 thread_finished = 1; 513 } 514 515 int 516 cpci_hp_register_controller(struct cpci_hp_controller *new_controller) 517 { 518 int status = 0; 519 520 if (controller) 521 return -1; 522 if (!(new_controller && new_controller->ops)) 523 return -EINVAL; 524 if (new_controller->irq) { 525 if (!(new_controller->ops->enable_irq && 526 new_controller->ops->disable_irq)) 527 status = -EINVAL; 528 if (request_irq(new_controller->irq, 529 cpci_hp_intr, 530 new_controller->irq_flags, 531 MY_NAME, 532 new_controller->dev_id)) { 533 err("Can't get irq %d for the hotplug cPCI controller", 534 new_controller->irq); 535 status = -ENODEV; 536 } 537 dbg("%s - acquired controller irq %d", 538 __func__, new_controller->irq); 539 } 540 if (!status) 541 controller = new_controller; 542 return status; 543 } 544 EXPORT_SYMBOL_GPL(cpci_hp_register_controller); 545 546 static void 547 cleanup_slots(void) 548 { 549 struct slot *slot; 550 struct slot *tmp; 551 552 /* 553 * Unregister all of our slots with the pci_hotplug subsystem, 554 * and free up all memory that we had allocated. 555 */ 556 down_write(&list_rwsem); 557 if (!slots) 558 goto cleanup_null; 559 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) { 560 list_del(&slot->slot_list); 561 pci_hp_deregister(&slot->hotplug_slot); 562 release_slot(slot); 563 } 564 cleanup_null: 565 up_write(&list_rwsem); 566 } 567 568 int 569 cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller) 570 { 571 int status = 0; 572 573 if (controller) { 574 if (!thread_finished) 575 cpci_stop_thread(); 576 if (controller->irq) 577 free_irq(controller->irq, controller->dev_id); 578 controller = NULL; 579 cleanup_slots(); 580 } else 581 status = -ENODEV; 582 return status; 583 } 584 EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller); 585 586 int 587 cpci_hp_start(void) 588 { 589 static int first = 1; 590 int status; 591 592 dbg("%s - enter", __func__); 593 if (!controller) 594 return -ENODEV; 595 596 down_read(&list_rwsem); 597 if (list_empty(&slot_list)) { 598 up_read(&list_rwsem); 599 return -ENODEV; 600 } 601 up_read(&list_rwsem); 602 603 status = init_slots(first); 604 if (first) 605 first = 0; 606 if (status) 607 return status; 608 609 status = cpci_start_thread(); 610 if (status) 611 return status; 612 dbg("%s - thread started", __func__); 613 614 if (controller->irq) { 615 /* Start enum interrupt processing */ 616 dbg("%s - enabling irq", __func__); 617 controller->ops->enable_irq(); 618 } 619 dbg("%s - exit", __func__); 620 return 0; 621 } 622 EXPORT_SYMBOL_GPL(cpci_hp_start); 623 624 int 625 cpci_hp_stop(void) 626 { 627 if (!controller) 628 return -ENODEV; 629 if (controller->irq) { 630 /* Stop enum interrupt processing */ 631 dbg("%s - disabling irq", __func__); 632 controller->ops->disable_irq(); 633 } 634 cpci_stop_thread(); 635 return 0; 636 } 637 EXPORT_SYMBOL_GPL(cpci_hp_stop); 638 639 int __init 640 cpci_hotplug_init(int debug) 641 { 642 cpci_debug = debug; 643 return 0; 644 } 645