]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/pci/hotplug/cpci_hotplug_core.c
sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched...
[mirror_ubuntu-artful-kernel.git] / drivers / pci / hotplug / cpci_hotplug_core.c
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/sched/signal.h>
31 #include <linux/slab.h>
32 #include <linux/pci.h>
33 #include <linux/pci_hotplug.h>
34 #include <linux/init.h>
35 #include <linux/interrupt.h>
36 #include <linux/atomic.h>
37 #include <linux/delay.h>
38 #include <linux/kthread.h>
39 #include "cpci_hotplug.h"
40
41 #define DRIVER_AUTHOR "Scott Murray <scottm@somanetworks.com>"
42 #define DRIVER_DESC "CompactPCI Hot Plug Core"
43
44 #define MY_NAME "cpci_hotplug"
45
46 #define dbg(format, arg...) \
47 do { \
48 if (cpci_debug) \
49 printk(KERN_DEBUG "%s: " format "\n", \
50 MY_NAME, ## arg); \
51 } while (0)
52 #define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg)
53 #define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg)
54 #define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg)
55
56 /* local variables */
57 static DECLARE_RWSEM(list_rwsem);
58 static LIST_HEAD(slot_list);
59 static int slots;
60 static atomic_t extracting;
61 int cpci_debug;
62 static struct cpci_hp_controller *controller;
63 static struct task_struct *cpci_thread;
64 static int thread_finished;
65
66 static int enable_slot(struct hotplug_slot *slot);
67 static int disable_slot(struct hotplug_slot *slot);
68 static int set_attention_status(struct hotplug_slot *slot, u8 value);
69 static int get_power_status(struct hotplug_slot *slot, u8 *value);
70 static int get_attention_status(struct hotplug_slot *slot, u8 *value);
71 static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
72 static int get_latch_status(struct hotplug_slot *slot, u8 *value);
73
74 static struct hotplug_slot_ops cpci_hotplug_slot_ops = {
75 .enable_slot = enable_slot,
76 .disable_slot = disable_slot,
77 .set_attention_status = set_attention_status,
78 .get_power_status = get_power_status,
79 .get_attention_status = get_attention_status,
80 .get_adapter_status = get_adapter_status,
81 .get_latch_status = get_latch_status,
82 };
83
84 static int
85 update_latch_status(struct hotplug_slot *hotplug_slot, u8 value)
86 {
87 struct hotplug_slot_info info;
88
89 memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info));
90 info.latch_status = value;
91 return pci_hp_change_slot_info(hotplug_slot, &info);
92 }
93
94 static int
95 update_adapter_status(struct hotplug_slot *hotplug_slot, u8 value)
96 {
97 struct hotplug_slot_info info;
98
99 memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info));
100 info.adapter_status = value;
101 return pci_hp_change_slot_info(hotplug_slot, &info);
102 }
103
104 static int
105 enable_slot(struct hotplug_slot *hotplug_slot)
106 {
107 struct slot *slot = hotplug_slot->private;
108 int retval = 0;
109
110 dbg("%s - physical_slot = %s", __func__, slot_name(slot));
111
112 if (controller->ops->set_power)
113 retval = controller->ops->set_power(slot, 1);
114 return retval;
115 }
116
117 static int
118 disable_slot(struct hotplug_slot *hotplug_slot)
119 {
120 struct slot *slot = hotplug_slot->private;
121 int retval = 0;
122
123 dbg("%s - physical_slot = %s", __func__, slot_name(slot));
124
125 down_write(&list_rwsem);
126
127 /* Unconfigure device */
128 dbg("%s - unconfiguring slot %s", __func__, slot_name(slot));
129 retval = cpci_unconfigure_slot(slot);
130 if (retval) {
131 err("%s - could not unconfigure slot %s",
132 __func__, slot_name(slot));
133 goto disable_error;
134 }
135 dbg("%s - finished unconfiguring slot %s", __func__, slot_name(slot));
136
137 /* Clear EXT (by setting it) */
138 if (cpci_clear_ext(slot)) {
139 err("%s - could not clear EXT for slot %s",
140 __func__, slot_name(slot));
141 retval = -ENODEV;
142 goto disable_error;
143 }
144 cpci_led_on(slot);
145
146 if (controller->ops->set_power) {
147 retval = controller->ops->set_power(slot, 0);
148 if (retval)
149 goto disable_error;
150 }
151
152 if (update_adapter_status(slot->hotplug_slot, 0))
153 warn("failure to update adapter file");
154
155 if (slot->extracting) {
156 slot->extracting = 0;
157 atomic_dec(&extracting);
158 }
159 disable_error:
160 up_write(&list_rwsem);
161 return retval;
162 }
163
164 static u8
165 cpci_get_power_status(struct slot *slot)
166 {
167 u8 power = 1;
168
169 if (controller->ops->get_power)
170 power = controller->ops->get_power(slot);
171 return power;
172 }
173
174 static int
175 get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
176 {
177 struct slot *slot = hotplug_slot->private;
178
179 *value = cpci_get_power_status(slot);
180 return 0;
181 }
182
183 static int
184 get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
185 {
186 struct slot *slot = hotplug_slot->private;
187
188 *value = cpci_get_attention_status(slot);
189 return 0;
190 }
191
192 static int
193 set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
194 {
195 return cpci_set_attention_status(hotplug_slot->private, status);
196 }
197
198 static int
199 get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
200 {
201 *value = hotplug_slot->info->adapter_status;
202 return 0;
203 }
204
205 static int
206 get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
207 {
208 *value = hotplug_slot->info->latch_status;
209 return 0;
210 }
211
212 static void release_slot(struct hotplug_slot *hotplug_slot)
213 {
214 struct slot *slot = hotplug_slot->private;
215
216 kfree(slot->hotplug_slot->info);
217 kfree(slot->hotplug_slot);
218 pci_dev_put(slot->dev);
219 kfree(slot);
220 }
221
222 #define SLOT_NAME_SIZE 6
223
224 int
225 cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last)
226 {
227 struct slot *slot;
228 struct hotplug_slot *hotplug_slot;
229 struct hotplug_slot_info *info;
230 char name[SLOT_NAME_SIZE];
231 int status;
232 int i;
233
234 if (!(controller && bus))
235 return -ENODEV;
236
237 /*
238 * Create a structure for each slot, and register that slot
239 * with the pci_hotplug subsystem.
240 */
241 for (i = first; i <= last; ++i) {
242 slot = kzalloc(sizeof(struct slot), GFP_KERNEL);
243 if (!slot) {
244 status = -ENOMEM;
245 goto error;
246 }
247
248 hotplug_slot =
249 kzalloc(sizeof(struct hotplug_slot), GFP_KERNEL);
250 if (!hotplug_slot) {
251 status = -ENOMEM;
252 goto error_slot;
253 }
254 slot->hotplug_slot = hotplug_slot;
255
256 info = kzalloc(sizeof(struct hotplug_slot_info), GFP_KERNEL);
257 if (!info) {
258 status = -ENOMEM;
259 goto error_hpslot;
260 }
261 hotplug_slot->info = info;
262
263 slot->bus = bus;
264 slot->number = i;
265 slot->devfn = PCI_DEVFN(i, 0);
266
267 snprintf(name, SLOT_NAME_SIZE, "%02x:%02x", bus->number, i);
268
269 hotplug_slot->private = slot;
270 hotplug_slot->release = &release_slot;
271 hotplug_slot->ops = &cpci_hotplug_slot_ops;
272
273 /*
274 * Initialize the slot info structure with some known
275 * good values.
276 */
277 dbg("initializing slot %s", name);
278 info->power_status = cpci_get_power_status(slot);
279 info->attention_status = cpci_get_attention_status(slot);
280
281 dbg("registering slot %s", name);
282 status = pci_hp_register(slot->hotplug_slot, bus, i, name);
283 if (status) {
284 err("pci_hp_register failed with error %d", status);
285 goto error_info;
286 }
287 dbg("slot registered with name: %s", slot_name(slot));
288
289 /* Add slot to our internal list */
290 down_write(&list_rwsem);
291 list_add(&slot->slot_list, &slot_list);
292 slots++;
293 up_write(&list_rwsem);
294 }
295 return 0;
296 error_info:
297 kfree(info);
298 error_hpslot:
299 kfree(hotplug_slot);
300 error_slot:
301 kfree(slot);
302 error:
303 return status;
304 }
305 EXPORT_SYMBOL_GPL(cpci_hp_register_bus);
306
307 int
308 cpci_hp_unregister_bus(struct pci_bus *bus)
309 {
310 struct slot *slot;
311 struct slot *tmp;
312 int status = 0;
313
314 down_write(&list_rwsem);
315 if (!slots) {
316 up_write(&list_rwsem);
317 return -1;
318 }
319 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
320 if (slot->bus == bus) {
321 list_del(&slot->slot_list);
322 slots--;
323
324 dbg("deregistering slot %s", slot_name(slot));
325 status = pci_hp_deregister(slot->hotplug_slot);
326 if (status) {
327 err("pci_hp_deregister failed with error %d",
328 status);
329 break;
330 }
331 }
332 }
333 up_write(&list_rwsem);
334 return status;
335 }
336 EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus);
337
338 /* This is the interrupt mode interrupt handler */
339 static irqreturn_t
340 cpci_hp_intr(int irq, void *data)
341 {
342 dbg("entered cpci_hp_intr");
343
344 /* Check to see if it was our interrupt */
345 if ((controller->irq_flags & IRQF_SHARED) &&
346 !controller->ops->check_irq(controller->dev_id)) {
347 dbg("exited cpci_hp_intr, not our interrupt");
348 return IRQ_NONE;
349 }
350
351 /* Disable ENUM interrupt */
352 controller->ops->disable_irq();
353
354 /* Trigger processing by the event thread */
355 wake_up_process(cpci_thread);
356 return IRQ_HANDLED;
357 }
358
359 /*
360 * According to PICMG 2.1 R2.0, section 6.3.2, upon
361 * initialization, the system driver shall clear the
362 * INS bits of the cold-inserted devices.
363 */
364 static int
365 init_slots(int clear_ins)
366 {
367 struct slot *slot;
368 struct pci_dev *dev;
369
370 dbg("%s - enter", __func__);
371 down_read(&list_rwsem);
372 if (!slots) {
373 up_read(&list_rwsem);
374 return -1;
375 }
376 list_for_each_entry(slot, &slot_list, slot_list) {
377 dbg("%s - looking at slot %s", __func__, slot_name(slot));
378 if (clear_ins && cpci_check_and_clear_ins(slot))
379 dbg("%s - cleared INS for slot %s",
380 __func__, slot_name(slot));
381 dev = pci_get_slot(slot->bus, PCI_DEVFN(slot->number, 0));
382 if (dev) {
383 if (update_adapter_status(slot->hotplug_slot, 1))
384 warn("failure to update adapter file");
385 if (update_latch_status(slot->hotplug_slot, 1))
386 warn("failure to update latch file");
387 slot->dev = dev;
388 }
389 }
390 up_read(&list_rwsem);
391 dbg("%s - exit", __func__);
392 return 0;
393 }
394
395 static int
396 check_slots(void)
397 {
398 struct slot *slot;
399 int extracted;
400 int inserted;
401 u16 hs_csr;
402
403 down_read(&list_rwsem);
404 if (!slots) {
405 up_read(&list_rwsem);
406 err("no slots registered, shutting down");
407 return -1;
408 }
409 extracted = inserted = 0;
410 list_for_each_entry(slot, &slot_list, slot_list) {
411 dbg("%s - looking at slot %s", __func__, slot_name(slot));
412 if (cpci_check_and_clear_ins(slot)) {
413 /*
414 * Some broken hardware (e.g. PLX 9054AB) asserts
415 * ENUM# twice...
416 */
417 if (slot->dev) {
418 warn("slot %s already inserted",
419 slot_name(slot));
420 inserted++;
421 continue;
422 }
423
424 /* Process insertion */
425 dbg("%s - slot %s inserted", __func__, slot_name(slot));
426
427 /* GSM, debug */
428 hs_csr = cpci_get_hs_csr(slot);
429 dbg("%s - slot %s HS_CSR (1) = %04x",
430 __func__, slot_name(slot), hs_csr);
431
432 /* Configure device */
433 dbg("%s - configuring slot %s",
434 __func__, slot_name(slot));
435 if (cpci_configure_slot(slot)) {
436 err("%s - could not configure slot %s",
437 __func__, slot_name(slot));
438 continue;
439 }
440 dbg("%s - finished configuring slot %s",
441 __func__, slot_name(slot));
442
443 /* GSM, debug */
444 hs_csr = cpci_get_hs_csr(slot);
445 dbg("%s - slot %s HS_CSR (2) = %04x",
446 __func__, slot_name(slot), hs_csr);
447
448 if (update_latch_status(slot->hotplug_slot, 1))
449 warn("failure to update latch file");
450
451 if (update_adapter_status(slot->hotplug_slot, 1))
452 warn("failure to update adapter file");
453
454 cpci_led_off(slot);
455
456 /* GSM, debug */
457 hs_csr = cpci_get_hs_csr(slot);
458 dbg("%s - slot %s HS_CSR (3) = %04x",
459 __func__, slot_name(slot), hs_csr);
460
461 inserted++;
462 } else if (cpci_check_ext(slot)) {
463 /* Process extraction request */
464 dbg("%s - slot %s extracted",
465 __func__, slot_name(slot));
466
467 /* GSM, debug */
468 hs_csr = cpci_get_hs_csr(slot);
469 dbg("%s - slot %s HS_CSR = %04x",
470 __func__, slot_name(slot), hs_csr);
471
472 if (!slot->extracting) {
473 if (update_latch_status(slot->hotplug_slot, 0))
474 warn("failure to update latch file");
475
476 slot->extracting = 1;
477 atomic_inc(&extracting);
478 }
479 extracted++;
480 } else if (slot->extracting) {
481 hs_csr = cpci_get_hs_csr(slot);
482 if (hs_csr == 0xffff) {
483 /*
484 * Hmmm, we're likely hosed at this point, should we
485 * bother trying to tell the driver or not?
486 */
487 err("card in slot %s was improperly removed",
488 slot_name(slot));
489 if (update_adapter_status(slot->hotplug_slot, 0))
490 warn("failure to update adapter file");
491 slot->extracting = 0;
492 atomic_dec(&extracting);
493 }
494 }
495 }
496 up_read(&list_rwsem);
497 dbg("inserted=%d, extracted=%d, extracting=%d",
498 inserted, extracted, atomic_read(&extracting));
499 if (inserted || extracted)
500 return extracted;
501 else if (!atomic_read(&extracting)) {
502 err("cannot find ENUM# source, shutting down");
503 return -1;
504 }
505 return 0;
506 }
507
508 /* This is the interrupt mode worker thread body */
509 static int
510 event_thread(void *data)
511 {
512 int rc;
513
514 dbg("%s - event thread started", __func__);
515 while (1) {
516 dbg("event thread sleeping");
517 set_current_state(TASK_INTERRUPTIBLE);
518 schedule();
519 if (kthread_should_stop())
520 break;
521 do {
522 rc = check_slots();
523 if (rc > 0) {
524 /* Give userspace a chance to handle extraction */
525 msleep(500);
526 } else if (rc < 0) {
527 dbg("%s - error checking slots", __func__);
528 thread_finished = 1;
529 goto out;
530 }
531 } while (atomic_read(&extracting) && !kthread_should_stop());
532 if (kthread_should_stop())
533 break;
534
535 /* Re-enable ENUM# interrupt */
536 dbg("%s - re-enabling irq", __func__);
537 controller->ops->enable_irq();
538 }
539 out:
540 return 0;
541 }
542
543 /* This is the polling mode worker thread body */
544 static int
545 poll_thread(void *data)
546 {
547 int rc;
548
549 while (1) {
550 if (kthread_should_stop() || signal_pending(current))
551 break;
552 if (controller->ops->query_enum()) {
553 do {
554 rc = check_slots();
555 if (rc > 0) {
556 /* Give userspace a chance to handle extraction */
557 msleep(500);
558 } else if (rc < 0) {
559 dbg("%s - error checking slots", __func__);
560 thread_finished = 1;
561 goto out;
562 }
563 } while (atomic_read(&extracting) && !kthread_should_stop());
564 }
565 msleep(100);
566 }
567 out:
568 return 0;
569 }
570
571 static int
572 cpci_start_thread(void)
573 {
574 if (controller->irq)
575 cpci_thread = kthread_run(event_thread, NULL, "cpci_hp_eventd");
576 else
577 cpci_thread = kthread_run(poll_thread, NULL, "cpci_hp_polld");
578 if (IS_ERR(cpci_thread)) {
579 err("Can't start up our thread");
580 return PTR_ERR(cpci_thread);
581 }
582 thread_finished = 0;
583 return 0;
584 }
585
586 static void
587 cpci_stop_thread(void)
588 {
589 kthread_stop(cpci_thread);
590 thread_finished = 1;
591 }
592
593 int
594 cpci_hp_register_controller(struct cpci_hp_controller *new_controller)
595 {
596 int status = 0;
597
598 if (controller)
599 return -1;
600 if (!(new_controller && new_controller->ops))
601 return -EINVAL;
602 if (new_controller->irq) {
603 if (!(new_controller->ops->enable_irq &&
604 new_controller->ops->disable_irq))
605 status = -EINVAL;
606 if (request_irq(new_controller->irq,
607 cpci_hp_intr,
608 new_controller->irq_flags,
609 MY_NAME,
610 new_controller->dev_id)) {
611 err("Can't get irq %d for the hotplug cPCI controller",
612 new_controller->irq);
613 status = -ENODEV;
614 }
615 dbg("%s - acquired controller irq %d",
616 __func__, new_controller->irq);
617 }
618 if (!status)
619 controller = new_controller;
620 return status;
621 }
622 EXPORT_SYMBOL_GPL(cpci_hp_register_controller);
623
624 static void
625 cleanup_slots(void)
626 {
627 struct slot *slot;
628 struct slot *tmp;
629
630 /*
631 * Unregister all of our slots with the pci_hotplug subsystem,
632 * and free up all memory that we had allocated.
633 */
634 down_write(&list_rwsem);
635 if (!slots)
636 goto cleanup_null;
637 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
638 list_del(&slot->slot_list);
639 pci_hp_deregister(slot->hotplug_slot);
640 }
641 cleanup_null:
642 up_write(&list_rwsem);
643 return;
644 }
645
646 int
647 cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller)
648 {
649 int status = 0;
650
651 if (controller) {
652 if (!thread_finished)
653 cpci_stop_thread();
654 if (controller->irq)
655 free_irq(controller->irq, controller->dev_id);
656 controller = NULL;
657 cleanup_slots();
658 } else
659 status = -ENODEV;
660 return status;
661 }
662 EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller);
663
664 int
665 cpci_hp_start(void)
666 {
667 static int first = 1;
668 int status;
669
670 dbg("%s - enter", __func__);
671 if (!controller)
672 return -ENODEV;
673
674 down_read(&list_rwsem);
675 if (list_empty(&slot_list)) {
676 up_read(&list_rwsem);
677 return -ENODEV;
678 }
679 up_read(&list_rwsem);
680
681 status = init_slots(first);
682 if (first)
683 first = 0;
684 if (status)
685 return status;
686
687 status = cpci_start_thread();
688 if (status)
689 return status;
690 dbg("%s - thread started", __func__);
691
692 if (controller->irq) {
693 /* Start enum interrupt processing */
694 dbg("%s - enabling irq", __func__);
695 controller->ops->enable_irq();
696 }
697 dbg("%s - exit", __func__);
698 return 0;
699 }
700 EXPORT_SYMBOL_GPL(cpci_hp_start);
701
702 int
703 cpci_hp_stop(void)
704 {
705 if (!controller)
706 return -ENODEV;
707 if (controller->irq) {
708 /* Stop enum interrupt processing */
709 dbg("%s - disabling irq", __func__);
710 controller->ops->disable_irq();
711 }
712 cpci_stop_thread();
713 return 0;
714 }
715 EXPORT_SYMBOL_GPL(cpci_hp_stop);
716
717 int __init
718 cpci_hotplug_init(int debug)
719 {
720 cpci_debug = debug;
721 return 0;
722 }