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
update_latch_status(struct hotplug_slot * hotplug_slot,u8 value)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
update_adapter_status(struct hotplug_slot * hotplug_slot,u8 value)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
enable_slot(struct hotplug_slot * hotplug_slot)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
disable_slot(struct hotplug_slot * hotplug_slot)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
cpci_get_power_status(struct slot * slot)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
get_power_status(struct hotplug_slot * hotplug_slot,u8 * value)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
get_attention_status(struct hotplug_slot * hotplug_slot,u8 * value)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
set_attention_status(struct hotplug_slot * hotplug_slot,u8 status)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
get_adapter_status(struct hotplug_slot * hotplug_slot,u8 * value)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
get_latch_status(struct hotplug_slot * hotplug_slot,u8 * value)202 get_latch_status(struct hotplug_slot *hotplug_slot, u8 * value)
203 {
204 *value = hotplug_slot->info->latch_status;
205 return 0;
206 }
207
release_slot(struct hotplug_slot * hotplug_slot)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
cpci_hp_register_bus(struct pci_bus * bus,u8 first,u8 last)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
cpci_hp_unregister_bus(struct pci_bus * bus)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
cpci_hp_intr(int irq,void * data)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
init_slots(int clear_ins)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
check_slots(void)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
event_thread(void * data)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
poll_thread(void * data)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
cpci_start_thread(void)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
cpci_stop_thread(void)576 cpci_stop_thread(void)
577 {
578 kthread_stop(cpci_thread);
579 thread_finished = 1;
580 }
581
582 int
cpci_hp_register_controller(struct cpci_hp_controller * new_controller)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
cleanup_slots(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
cpci_hp_unregister_controller(struct cpci_hp_controller * old_controller)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
cpci_hp_start(void)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
cpci_hp_stop(void)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
cpci_hotplug_init(int debug)703 cpci_hotplug_init(int debug)
704 {
705 cpci_debug = debug;
706 return 0;
707 }
708
709 void __exit
cpci_hotplug_exit(void)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