powerpc/pci/rpadlpar: Fix device reference leaks
[pandora-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/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/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
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
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
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
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
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
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
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
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
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
202 get_latch_status(struct hotplug_slot *hotplug_slot, u8 * value)
203 {
204         *value = hotplug_slot->info->latch_status;
205         return 0;
206 }
207
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
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
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
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
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
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
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
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
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
576 cpci_stop_thread(void)
577 {
578         kthread_stop(cpci_thread);
579         thread_finished = 1;
580 }
581
582 int
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
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
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
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
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
703 cpci_hotplug_init(int debug)
704 {
705         cpci_debug = debug;
706         return 0;
707 }
708
709 void __exit
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);