GNU Linux-libre 4.14.290-gnu1
[releases.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 }