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1// SPDX-License-Identifier: GPL-2.0+2/*3 * CompactPCI Hot Plug Driver4 *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 */43static DECLARE_RWSEM(list_rwsem);44static LIST_HEAD(slot_list);45static int slots;46static atomic_t extracting;47int cpci_debug;48static struct cpci_hp_controller *controller;49static struct task_struct *cpci_thread;50static int thread_finished;51 52static int enable_slot(struct hotplug_slot *slot);53static int disable_slot(struct hotplug_slot *slot);54static int set_attention_status(struct hotplug_slot *slot, u8 value);55static int get_power_status(struct hotplug_slot *slot, u8 *value);56static int get_attention_status(struct hotplug_slot *slot, u8 *value);57static int get_adapter_status(struct hotplug_slot *slot, u8 *value);58static int get_latch_status(struct hotplug_slot *slot, u8 *value);59 60static 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 70static int71enable_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 83static int84disable_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 }124disable_error:125 up_write(&list_rwsem);126 return retval;127}128 129static u8130cpci_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 139static int140get_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 148static int149get_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 157static int158set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)159{160 return cpci_set_attention_status(to_slot(hotplug_slot), status);161}162 163static int164get_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 172static int173get_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 181static void release_slot(struct slot *slot)182{183 pci_dev_put(slot->dev);184 kfree(slot);185}186 187#define SLOT_NAME_SIZE 6188 189int190cpci_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 slot202 * 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;234error_slot:235 kfree(slot);236error:237 return status;238}239EXPORT_SYMBOL_GPL(cpci_hp_register_bus);240 241int242cpci_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}266EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus);267 268/* This is the interrupt mode interrupt handler */269static irqreturn_t270cpci_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, upon291 * initialization, the system driver shall clear the292 * INS bits of the cold-inserted devices.293 */294static int295init_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 323static int324check_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) asserts343 * 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 we408 * 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 */431static int432event_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 */466static int467poll_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 493static int494cpci_start_thread(void)495{496 if (controller->irq)497 cpci_thread = kthread_run(event_thread, NULL, "cpci_hp_eventd");498 else499 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 508static void509cpci_stop_thread(void)510{511 kthread_stop(cpci_thread);512 thread_finished = 1;513}514 515int516cpci_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}544EXPORT_SYMBOL_GPL(cpci_hp_register_controller);545 546static void547cleanup_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 }564cleanup_null:565 up_write(&list_rwsem);566}567 568int569cpci_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 } else581 status = -ENODEV;582 return status;583}584EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller);585 586int587cpci_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}622EXPORT_SYMBOL_GPL(cpci_hp_start);623 624int625cpci_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}637EXPORT_SYMBOL_GPL(cpci_hp_stop);638 639int __init640cpci_hotplug_init(int debug)641{642 cpci_debug = debug;643 return 0;644}645