Merge branch 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6] / 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/smp_lock.h>
36 #include <asm/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         .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,
83 };
84
85 static int
86 update_latch_status(struct hotplug_slot *hotplug_slot, u8 value)
87 {
88         struct hotplug_slot_info info;
89
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);
93 }
94
95 static int
96 update_adapter_status(struct hotplug_slot *hotplug_slot, u8 value)
97 {
98         struct hotplug_slot_info info;
99
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);
103 }
104
105 static int
106 enable_slot(struct hotplug_slot *hotplug_slot)
107 {
108         struct slot *slot = hotplug_slot->private;
109         int retval = 0;
110
111         dbg("%s - physical_slot = %s", __func__, hotplug_slot->name);
112
113         if (controller->ops->set_power)
114                 retval = controller->ops->set_power(slot, 1);
115         return retval;
116 }
117
118 static int
119 disable_slot(struct hotplug_slot *hotplug_slot)
120 {
121         struct slot *slot = hotplug_slot->private;
122         int retval = 0;
123
124         dbg("%s - physical_slot = %s", __func__, hotplug_slot->name);
125
126         down_write(&list_rwsem);
127
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;
135         }
136         dbg("%s - finished unconfiguring slot %s",
137             __func__, slot->hotplug_slot->name);
138
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;
145         }
146         cpci_led_on(slot);
147
148         if (controller->ops->set_power)
149                 if ((retval = controller->ops->set_power(slot, 0)))
150                         goto disable_error;
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->name);
218         kfree(slot->hotplug_slot);
219         if (slot->dev)
220                 pci_dev_put(slot->dev);
221         kfree(slot);
222 }
223
224 #define SLOT_NAME_SIZE  6
225 static void
226 make_slot_name(struct slot *slot)
227 {
228         snprintf(slot->hotplug_slot->name,
229                  SLOT_NAME_SIZE, "%02x:%02x", slot->bus->number, slot->number);
230 }
231
232 int
233 cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last)
234 {
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;
241
242         if (!(controller && bus))
243                 return -ENODEV;
244
245         /*
246          * Create a structure for each slot, and register that slot
247          * with the pci_hotplug subsystem.
248          */
249         for (i = first; i <= last; ++i) {
250                 slot = kzalloc(sizeof (struct slot), GFP_KERNEL);
251                 if (!slot)
252                         goto error;
253
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;
259
260                 info = kzalloc(sizeof (struct hotplug_slot_info), GFP_KERNEL);
261                 if (!info)
262                         goto error_hpslot;
263                 hotplug_slot->info = info;
264
265                 name = kmalloc(SLOT_NAME_SIZE, GFP_KERNEL);
266                 if (!name)
267                         goto error_info;
268                 hotplug_slot->name = name;
269
270                 slot->bus = bus;
271                 slot->number = i;
272                 slot->devfn = PCI_DEVFN(i, 0);
273
274                 hotplug_slot->private = slot;
275                 hotplug_slot->release = &release_slot;
276                 make_slot_name(slot);
277                 hotplug_slot->ops = &cpci_hotplug_slot_ops;
278
279                 /*
280                  * Initialize the slot info structure with some known
281                  * good values.
282                  */
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);
286
287                 dbg("registering slot %s", slot->hotplug_slot->name);
288                 status = pci_hp_register(slot->hotplug_slot);
289                 if (status) {
290                         err("pci_hp_register failed with error %d", status);
291                         goto error_name;
292                 }
293
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);
299         }
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;
311 }
312
313 int
314 cpci_hp_unregister_bus(struct pci_bus *bus)
315 {
316         struct slot *slot;
317         struct slot *tmp;
318         int status = 0;
319
320         down_write(&list_rwsem);
321         if (!slots) {
322                 up_write(&list_rwsem);
323                 return -1;
324         }
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--;
329
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;
336                         }
337                 }
338         }
339         up_write(&list_rwsem);
340         return status;
341 }
342
343 /* This is the interrupt mode interrupt handler */
344 static irqreturn_t
345 cpci_hp_intr(int irq, void *data)
346 {
347         dbg("entered cpci_hp_intr");
348
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;
354         }
355
356         /* Disable ENUM interrupt */
357         controller->ops->disable_irq();
358
359         /* Trigger processing by the event thread */
360         wake_up_process(cpci_thread);
361         return IRQ_HANDLED;
362 }
363
364 /*
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.
368  */
369 static int
370 init_slots(int clear_ins)
371 {
372         struct slot *slot;
373         struct pci_dev* dev;
374
375         dbg("%s - enter", __func__);
376         down_read(&list_rwsem);
377         if (!slots) {
378                 up_read(&list_rwsem);
379                 return -1;
380         }
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;
394                 }
395         }
396         up_read(&list_rwsem);
397         dbg("%s - exit", __func__);
398         return 0;
399 }
400
401 static int
402 check_slots(void)
403 {
404         struct slot *slot;
405         int extracted;
406         int inserted;
407         u16 hs_csr;
408
409         down_read(&list_rwsem);
410         if (!slots) {
411                 up_read(&list_rwsem);
412                 err("no slots registered, shutting down");
413                 return -1;
414         }
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)) {
420                         /*
421                          * Some broken hardware (e.g. PLX 9054AB) asserts
422                          * ENUM# twice...
423                          */
424                         if (slot->dev) {
425                                 warn("slot %s already inserted",
426                                      slot->hotplug_slot->name);
427                                 inserted++;
428                                 continue;
429                         }
430
431                         /* Process insertion */
432                         dbg("%s - slot %s inserted",
433                             __func__, slot->hotplug_slot->name);
434
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);
439
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;
447                         }
448                         dbg("%s - finished configuring slot %s",
449                             __func__, slot->hotplug_slot->name);
450
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);
455
456                         if (update_latch_status(slot->hotplug_slot, 1))
457                                 warn("failure to update latch file");
458
459                         if (update_adapter_status(slot->hotplug_slot, 1))
460                                 warn("failure to update adapter file");
461
462                         cpci_led_off(slot);
463
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);
468
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);
474
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);
479
480                         if (!slot->extracting) {
481                                 if (update_latch_status(slot->hotplug_slot, 0)) {
482                                         warn("failure to update latch file");
483                                 }
484                                 slot->extracting = 1;
485                                 atomic_inc(&extracting);
486                         }
487                         extracted++;
488                 } else if (slot->extracting) {
489                         hs_csr = cpci_get_hs_csr(slot);
490                         if (hs_csr == 0xffff) {
491                                 /*
492                                  * Hmmm, we're likely hosed at this point, should we
493                                  * bother trying to tell the driver or not?
494                                  */
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);
501                         }
502                 }
503         }
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;
512         }
513         return 0;
514 }
515
516 /* This is the interrupt mode worker thread body */
517 static int
518 event_thread(void *data)
519 {
520         int rc;
521
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;
538                         }
539                 } while (atomic_read(&extracting) && !kthread_should_stop());
540                 if (kthread_should_stop())
541                         break;
542
543                 /* Re-enable ENUM# interrupt */
544                 dbg("%s - re-enabling irq", __func__);
545                 controller->ops->enable_irq();
546         }
547  out:
548         return 0;
549 }
550
551 /* This is the polling mode worker thread body */
552 static int
553 poll_thread(void *data)
554 {
555         int rc;
556
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;
570                                 }
571                         } while (atomic_read(&extracting) && !kthread_should_stop());
572                 }
573                 msleep(100);
574         }
575  out:
576         return 0;
577 }
578
579 static int
580 cpci_start_thread(void)
581 {
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);
589         }
590         thread_finished = 0;
591         return 0;
592 }
593
594 static void
595 cpci_stop_thread(void)
596 {
597         kthread_stop(cpci_thread);
598         thread_finished = 1;
599 }
600
601 int
602 cpci_hp_register_controller(struct cpci_hp_controller *new_controller)
603 {
604         int status = 0;
605
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;
622                 }
623                 dbg("%s - acquired controller irq %d",
624                     __func__, new_controller->irq);
625         }
626         if (!status)
627                 controller = new_controller;
628         return status;
629 }
630
631 static void
632 cleanup_slots(void)
633 {
634         struct slot *slot;
635         struct slot *tmp;
636
637         /*
638          * Unregister all of our slots with the pci_hotplug subsystem,
639          * and free up all memory that we had allocated.
640          */
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);
647         }
648 cleanup_null:
649         up_write(&list_rwsem);
650         return;
651 }
652
653 int
654 cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller)
655 {
656         int status = 0;
657
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;
668 }
669
670 int
671 cpci_hp_start(void)
672 {
673         static int first = 1;
674         int status;
675
676         dbg("%s - enter", __func__);
677         if (!controller)
678                 return -ENODEV;
679
680         down_read(&list_rwsem);
681         if (list_empty(&slot_list)) {
682                 up_read(&list_rwsem);
683                 return -ENODEV;
684         }
685         up_read(&list_rwsem);
686
687         status = init_slots(first);
688         if (first)
689                 first = 0;
690         if (status)
691                 return status;
692
693         status = cpci_start_thread();
694         if (status)
695                 return status;
696         dbg("%s - thread started", __func__);
697
698         if (controller->irq) {
699                 /* Start enum interrupt processing */
700                 dbg("%s - enabling irq", __func__);
701                 controller->ops->enable_irq();
702         }
703         dbg("%s - exit", __func__);
704         return 0;
705 }
706
707 int
708 cpci_hp_stop(void)
709 {
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();
716         }
717         cpci_stop_thread();
718         return 0;
719 }
720
721 int __init
722 cpci_hotplug_init(int debug)
723 {
724         cpci_debug = debug;
725         return 0;
726 }
727
728 void __exit
729 cpci_hotplug_exit(void)
730 {
731         /*
732          * Clean everything up.
733          */
734         cpci_hp_stop();
735         cpci_hp_unregister_controller(controller);
736 }
737
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);