net: Fix recursive descent in __scm_destroy().
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / pci / hotplug / cpci_hotplug_core.c
blob935947991dc98649dfaa8794fb55604ee12cb895
1 /*
2 * CompactPCI Hot Plug Driver
4 * Copyright (C) 2002,2005 SOMA Networks, Inc.
5 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
6 * Copyright (C) 2001 IBM Corp.
8 * All rights reserved.
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.
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.
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.
25 * Send feedback to <scottm@somanetworks.com>
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 <linux/smp_lock.h>
36 #include <asm/atomic.h>
37 #include <linux/delay.h>
38 #include <linux/kthread.h>
39 #include "cpci_hotplug.h"
41 #define DRIVER_AUTHOR "Scott Murray <scottm@somanetworks.com>"
42 #define DRIVER_DESC "CompactPCI Hot Plug Core"
44 #define MY_NAME "cpci_hotplug"
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)
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;
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);
74 static struct hotplug_slot_ops cpci_hotplug_slot_ops = {
75 .owner = THIS_MODULE,
76 .enable_slot = enable_slot,
77 .disable_slot = disable_slot,
78 .set_attention_status = set_attention_status,
79 .get_power_status = get_power_status,
80 .get_attention_status = get_attention_status,
81 .get_adapter_status = get_adapter_status,
82 .get_latch_status = get_latch_status,
85 static int
86 update_latch_status(struct hotplug_slot *hotplug_slot, u8 value)
88 struct hotplug_slot_info info;
90 memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info));
91 info.latch_status = value;
92 return pci_hp_change_slot_info(hotplug_slot, &info);
95 static int
96 update_adapter_status(struct hotplug_slot *hotplug_slot, u8 value)
98 struct hotplug_slot_info info;
100 memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info));
101 info.adapter_status = value;
102 return pci_hp_change_slot_info(hotplug_slot, &info);
105 static int
106 enable_slot(struct hotplug_slot *hotplug_slot)
108 struct slot *slot = hotplug_slot->private;
109 int retval = 0;
111 dbg("%s - physical_slot = %s", __func__, hotplug_slot->name);
113 if (controller->ops->set_power)
114 retval = controller->ops->set_power(slot, 1);
115 return retval;
118 static int
119 disable_slot(struct hotplug_slot *hotplug_slot)
121 struct slot *slot = hotplug_slot->private;
122 int retval = 0;
124 dbg("%s - physical_slot = %s", __func__, hotplug_slot->name);
126 down_write(&list_rwsem);
128 /* Unconfigure device */
129 dbg("%s - unconfiguring slot %s",
130 __func__, slot->hotplug_slot->name);
131 if ((retval = cpci_unconfigure_slot(slot))) {
132 err("%s - could not unconfigure slot %s",
133 __func__, slot->hotplug_slot->name);
134 goto disable_error;
136 dbg("%s - finished unconfiguring slot %s",
137 __func__, slot->hotplug_slot->name);
139 /* Clear EXT (by setting it) */
140 if (cpci_clear_ext(slot)) {
141 err("%s - could not clear EXT for slot %s",
142 __func__, slot->hotplug_slot->name);
143 retval = -ENODEV;
144 goto disable_error;
146 cpci_led_on(slot);
148 if (controller->ops->set_power)
149 if ((retval = controller->ops->set_power(slot, 0)))
150 goto disable_error;
152 if (update_adapter_status(slot->hotplug_slot, 0))
153 warn("failure to update adapter file");
155 if (slot->extracting) {
156 slot->extracting = 0;
157 atomic_dec(&extracting);
159 disable_error:
160 up_write(&list_rwsem);
161 return retval;
164 static u8
165 cpci_get_power_status(struct slot *slot)
167 u8 power = 1;
169 if (controller->ops->get_power)
170 power = controller->ops->get_power(slot);
171 return power;
174 static int
175 get_power_status(struct hotplug_slot *hotplug_slot, u8 * value)
177 struct slot *slot = hotplug_slot->private;
179 *value = cpci_get_power_status(slot);
180 return 0;
183 static int
184 get_attention_status(struct hotplug_slot *hotplug_slot, u8 * value)
186 struct slot *slot = hotplug_slot->private;
188 *value = cpci_get_attention_status(slot);
189 return 0;
192 static int
193 set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
195 return cpci_set_attention_status(hotplug_slot->private, status);
198 static int
199 get_adapter_status(struct hotplug_slot *hotplug_slot, u8 * value)
201 *value = hotplug_slot->info->adapter_status;
202 return 0;
205 static int
206 get_latch_status(struct hotplug_slot *hotplug_slot, u8 * value)
208 *value = hotplug_slot->info->latch_status;
209 return 0;
212 static void release_slot(struct hotplug_slot *hotplug_slot)
214 struct slot *slot = hotplug_slot->private;
216 kfree(slot->hotplug_slot->info);
217 kfree(slot->hotplug_slot->name);
218 kfree(slot->hotplug_slot);
219 if (slot->dev)
220 pci_dev_put(slot->dev);
221 kfree(slot);
224 #define SLOT_NAME_SIZE 6
225 static void
226 make_slot_name(struct slot *slot)
228 snprintf(slot->hotplug_slot->name,
229 SLOT_NAME_SIZE, "%02x:%02x", slot->bus->number, slot->number);
233 cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last)
235 struct slot *slot;
236 struct hotplug_slot *hotplug_slot;
237 struct hotplug_slot_info *info;
238 char *name;
239 int status = -ENOMEM;
240 int i;
242 if (!(controller && bus))
243 return -ENODEV;
246 * Create a structure for each slot, and register that slot
247 * with the pci_hotplug subsystem.
249 for (i = first; i <= last; ++i) {
250 slot = kzalloc(sizeof (struct slot), GFP_KERNEL);
251 if (!slot)
252 goto error;
254 hotplug_slot =
255 kzalloc(sizeof (struct hotplug_slot), GFP_KERNEL);
256 if (!hotplug_slot)
257 goto error_slot;
258 slot->hotplug_slot = hotplug_slot;
260 info = kzalloc(sizeof (struct hotplug_slot_info), GFP_KERNEL);
261 if (!info)
262 goto error_hpslot;
263 hotplug_slot->info = info;
265 name = kmalloc(SLOT_NAME_SIZE, GFP_KERNEL);
266 if (!name)
267 goto error_info;
268 hotplug_slot->name = name;
270 slot->bus = bus;
271 slot->number = i;
272 slot->devfn = PCI_DEVFN(i, 0);
274 hotplug_slot->private = slot;
275 hotplug_slot->release = &release_slot;
276 make_slot_name(slot);
277 hotplug_slot->ops = &cpci_hotplug_slot_ops;
280 * Initialize the slot info structure with some known
281 * good values.
283 dbg("initializing slot %s", slot->hotplug_slot->name);
284 info->power_status = cpci_get_power_status(slot);
285 info->attention_status = cpci_get_attention_status(slot);
287 dbg("registering slot %s", slot->hotplug_slot->name);
288 status = pci_hp_register(slot->hotplug_slot, bus, i);
289 if (status) {
290 err("pci_hp_register failed with error %d", status);
291 goto error_name;
294 /* Add slot to our internal list */
295 down_write(&list_rwsem);
296 list_add(&slot->slot_list, &slot_list);
297 slots++;
298 up_write(&list_rwsem);
300 return 0;
301 error_name:
302 kfree(name);
303 error_info:
304 kfree(info);
305 error_hpslot:
306 kfree(hotplug_slot);
307 error_slot:
308 kfree(slot);
309 error:
310 return status;
314 cpci_hp_unregister_bus(struct pci_bus *bus)
316 struct slot *slot;
317 struct slot *tmp;
318 int status = 0;
320 down_write(&list_rwsem);
321 if (!slots) {
322 up_write(&list_rwsem);
323 return -1;
325 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
326 if (slot->bus == bus) {
327 list_del(&slot->slot_list);
328 slots--;
330 dbg("deregistering slot %s", slot->hotplug_slot->name);
331 status = pci_hp_deregister(slot->hotplug_slot);
332 if (status) {
333 err("pci_hp_deregister failed with error %d",
334 status);
335 break;
339 up_write(&list_rwsem);
340 return status;
343 /* This is the interrupt mode interrupt handler */
344 static irqreturn_t
345 cpci_hp_intr(int irq, void *data)
347 dbg("entered cpci_hp_intr");
349 /* Check to see if it was our interrupt */
350 if ((controller->irq_flags & IRQF_SHARED) &&
351 !controller->ops->check_irq(controller->dev_id)) {
352 dbg("exited cpci_hp_intr, not our interrupt");
353 return IRQ_NONE;
356 /* Disable ENUM interrupt */
357 controller->ops->disable_irq();
359 /* Trigger processing by the event thread */
360 wake_up_process(cpci_thread);
361 return IRQ_HANDLED;
365 * According to PICMG 2.1 R2.0, section 6.3.2, upon
366 * initialization, the system driver shall clear the
367 * INS bits of the cold-inserted devices.
369 static int
370 init_slots(int clear_ins)
372 struct slot *slot;
373 struct pci_dev* dev;
375 dbg("%s - enter", __func__);
376 down_read(&list_rwsem);
377 if (!slots) {
378 up_read(&list_rwsem);
379 return -1;
381 list_for_each_entry(slot, &slot_list, slot_list) {
382 dbg("%s - looking at slot %s",
383 __func__, slot->hotplug_slot->name);
384 if (clear_ins && cpci_check_and_clear_ins(slot))
385 dbg("%s - cleared INS for slot %s",
386 __func__, slot->hotplug_slot->name);
387 dev = pci_get_slot(slot->bus, PCI_DEVFN(slot->number, 0));
388 if (dev) {
389 if (update_adapter_status(slot->hotplug_slot, 1))
390 warn("failure to update adapter file");
391 if (update_latch_status(slot->hotplug_slot, 1))
392 warn("failure to update latch file");
393 slot->dev = dev;
396 up_read(&list_rwsem);
397 dbg("%s - exit", __func__);
398 return 0;
401 static int
402 check_slots(void)
404 struct slot *slot;
405 int extracted;
406 int inserted;
407 u16 hs_csr;
409 down_read(&list_rwsem);
410 if (!slots) {
411 up_read(&list_rwsem);
412 err("no slots registered, shutting down");
413 return -1;
415 extracted = inserted = 0;
416 list_for_each_entry(slot, &slot_list, slot_list) {
417 dbg("%s - looking at slot %s",
418 __func__, slot->hotplug_slot->name);
419 if (cpci_check_and_clear_ins(slot)) {
421 * Some broken hardware (e.g. PLX 9054AB) asserts
422 * ENUM# twice...
424 if (slot->dev) {
425 warn("slot %s already inserted",
426 slot->hotplug_slot->name);
427 inserted++;
428 continue;
431 /* Process insertion */
432 dbg("%s - slot %s inserted",
433 __func__, slot->hotplug_slot->name);
435 /* GSM, debug */
436 hs_csr = cpci_get_hs_csr(slot);
437 dbg("%s - slot %s HS_CSR (1) = %04x",
438 __func__, slot->hotplug_slot->name, hs_csr);
440 /* Configure device */
441 dbg("%s - configuring slot %s",
442 __func__, slot->hotplug_slot->name);
443 if (cpci_configure_slot(slot)) {
444 err("%s - could not configure slot %s",
445 __func__, slot->hotplug_slot->name);
446 continue;
448 dbg("%s - finished configuring slot %s",
449 __func__, slot->hotplug_slot->name);
451 /* GSM, debug */
452 hs_csr = cpci_get_hs_csr(slot);
453 dbg("%s - slot %s HS_CSR (2) = %04x",
454 __func__, slot->hotplug_slot->name, hs_csr);
456 if (update_latch_status(slot->hotplug_slot, 1))
457 warn("failure to update latch file");
459 if (update_adapter_status(slot->hotplug_slot, 1))
460 warn("failure to update adapter file");
462 cpci_led_off(slot);
464 /* GSM, debug */
465 hs_csr = cpci_get_hs_csr(slot);
466 dbg("%s - slot %s HS_CSR (3) = %04x",
467 __func__, slot->hotplug_slot->name, hs_csr);
469 inserted++;
470 } else if (cpci_check_ext(slot)) {
471 /* Process extraction request */
472 dbg("%s - slot %s extracted",
473 __func__, slot->hotplug_slot->name);
475 /* GSM, debug */
476 hs_csr = cpci_get_hs_csr(slot);
477 dbg("%s - slot %s HS_CSR = %04x",
478 __func__, slot->hotplug_slot->name, hs_csr);
480 if (!slot->extracting) {
481 if (update_latch_status(slot->hotplug_slot, 0)) {
482 warn("failure to update latch file");
484 slot->extracting = 1;
485 atomic_inc(&extracting);
487 extracted++;
488 } else if (slot->extracting) {
489 hs_csr = cpci_get_hs_csr(slot);
490 if (hs_csr == 0xffff) {
492 * Hmmm, we're likely hosed at this point, should we
493 * bother trying to tell the driver or not?
495 err("card in slot %s was improperly removed",
496 slot->hotplug_slot->name);
497 if (update_adapter_status(slot->hotplug_slot, 0))
498 warn("failure to update adapter file");
499 slot->extracting = 0;
500 atomic_dec(&extracting);
504 up_read(&list_rwsem);
505 dbg("inserted=%d, extracted=%d, extracting=%d",
506 inserted, extracted, atomic_read(&extracting));
507 if (inserted || extracted)
508 return extracted;
509 else if (!atomic_read(&extracting)) {
510 err("cannot find ENUM# source, shutting down");
511 return -1;
513 return 0;
516 /* This is the interrupt mode worker thread body */
517 static int
518 event_thread(void *data)
520 int rc;
522 dbg("%s - event thread started", __func__);
523 while (1) {
524 dbg("event thread sleeping");
525 set_current_state(TASK_INTERRUPTIBLE);
526 schedule();
527 if (kthread_should_stop())
528 break;
529 do {
530 rc = check_slots();
531 if (rc > 0) {
532 /* Give userspace a chance to handle extraction */
533 msleep(500);
534 } else if (rc < 0) {
535 dbg("%s - error checking slots", __func__);
536 thread_finished = 1;
537 goto out;
539 } while (atomic_read(&extracting) && !kthread_should_stop());
540 if (kthread_should_stop())
541 break;
543 /* Re-enable ENUM# interrupt */
544 dbg("%s - re-enabling irq", __func__);
545 controller->ops->enable_irq();
547 out:
548 return 0;
551 /* This is the polling mode worker thread body */
552 static int
553 poll_thread(void *data)
555 int rc;
557 while (1) {
558 if (kthread_should_stop() || signal_pending(current))
559 break;
560 if (controller->ops->query_enum()) {
561 do {
562 rc = check_slots();
563 if (rc > 0) {
564 /* Give userspace a chance to handle extraction */
565 msleep(500);
566 } else if (rc < 0) {
567 dbg("%s - error checking slots", __func__);
568 thread_finished = 1;
569 goto out;
571 } while (atomic_read(&extracting) && !kthread_should_stop());
573 msleep(100);
575 out:
576 return 0;
579 static int
580 cpci_start_thread(void)
582 if (controller->irq)
583 cpci_thread = kthread_run(event_thread, NULL, "cpci_hp_eventd");
584 else
585 cpci_thread = kthread_run(poll_thread, NULL, "cpci_hp_polld");
586 if (IS_ERR(cpci_thread)) {
587 err("Can't start up our thread");
588 return PTR_ERR(cpci_thread);
590 thread_finished = 0;
591 return 0;
594 static void
595 cpci_stop_thread(void)
597 kthread_stop(cpci_thread);
598 thread_finished = 1;
602 cpci_hp_register_controller(struct cpci_hp_controller *new_controller)
604 int status = 0;
606 if (controller)
607 return -1;
608 if (!(new_controller && new_controller->ops))
609 return -EINVAL;
610 if (new_controller->irq) {
611 if (!(new_controller->ops->enable_irq &&
612 new_controller->ops->disable_irq))
613 status = -EINVAL;
614 if (request_irq(new_controller->irq,
615 cpci_hp_intr,
616 new_controller->irq_flags,
617 MY_NAME,
618 new_controller->dev_id)) {
619 err("Can't get irq %d for the hotplug cPCI controller",
620 new_controller->irq);
621 status = -ENODEV;
623 dbg("%s - acquired controller irq %d",
624 __func__, new_controller->irq);
626 if (!status)
627 controller = new_controller;
628 return status;
631 static void
632 cleanup_slots(void)
634 struct slot *slot;
635 struct slot *tmp;
638 * Unregister all of our slots with the pci_hotplug subsystem,
639 * and free up all memory that we had allocated.
641 down_write(&list_rwsem);
642 if (!slots)
643 goto cleanup_null;
644 list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
645 list_del(&slot->slot_list);
646 pci_hp_deregister(slot->hotplug_slot);
648 cleanup_null:
649 up_write(&list_rwsem);
650 return;
654 cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller)
656 int status = 0;
658 if (controller) {
659 if (!thread_finished)
660 cpci_stop_thread();
661 if (controller->irq)
662 free_irq(controller->irq, controller->dev_id);
663 controller = NULL;
664 cleanup_slots();
665 } else
666 status = -ENODEV;
667 return status;
671 cpci_hp_start(void)
673 static int first = 1;
674 int status;
676 dbg("%s - enter", __func__);
677 if (!controller)
678 return -ENODEV;
680 down_read(&list_rwsem);
681 if (list_empty(&slot_list)) {
682 up_read(&list_rwsem);
683 return -ENODEV;
685 up_read(&list_rwsem);
687 status = init_slots(first);
688 if (first)
689 first = 0;
690 if (status)
691 return status;
693 status = cpci_start_thread();
694 if (status)
695 return status;
696 dbg("%s - thread started", __func__);
698 if (controller->irq) {
699 /* Start enum interrupt processing */
700 dbg("%s - enabling irq", __func__);
701 controller->ops->enable_irq();
703 dbg("%s - exit", __func__);
704 return 0;
708 cpci_hp_stop(void)
710 if (!controller)
711 return -ENODEV;
712 if (controller->irq) {
713 /* Stop enum interrupt processing */
714 dbg("%s - disabling irq", __func__);
715 controller->ops->disable_irq();
717 cpci_stop_thread();
718 return 0;
721 int __init
722 cpci_hotplug_init(int debug)
724 cpci_debug = debug;
725 return 0;
728 void __exit
729 cpci_hotplug_exit(void)
732 * Clean everything up.
734 cpci_hp_stop();
735 cpci_hp_unregister_controller(controller);
738 EXPORT_SYMBOL_GPL(cpci_hp_register_controller);
739 EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller);
740 EXPORT_SYMBOL_GPL(cpci_hp_register_bus);
741 EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus);
742 EXPORT_SYMBOL_GPL(cpci_hp_start);
743 EXPORT_SYMBOL_GPL(cpci_hp_stop);