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