summaryrefslogtreecommitdiff
path: root/drivers/pci/hotplug/cpci_hotplug_core.c
blob: a5b9f6ae507bb5cf23ab4cf614e97c1fa7e2c6d3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
/*
 * CompactPCI Hot Plug Driver
 *
 * Copyright (C) 2002,2005 SOMA Networks, Inc.
 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
 * Copyright (C) 2001 IBM Corp.
 *
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Send feedback to <scottm@somanetworks.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/smp_lock.h>
#include <asm/atomic.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include "cpci_hotplug.h"

#define DRIVER_AUTHOR	"Scott Murray <scottm@somanetworks.com>"
#define DRIVER_DESC	"CompactPCI Hot Plug Core"

#define MY_NAME	"cpci_hotplug"

#define dbg(format, arg...)					\
	do {							\
		if (cpci_debug)					\
			printk (KERN_DEBUG "%s: " format "\n",	\
				MY_NAME , ## arg); 		\
	} while (0)
#define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME , ## arg)
#define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME , ## arg)
#define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME , ## arg)

/* local variables */
static DECLARE_RWSEM(list_rwsem);
static LIST_HEAD(slot_list);
static int slots;
static atomic_t extracting;
int cpci_debug;
static struct cpci_hp_controller *controller;
static struct task_struct *cpci_thread;
static int thread_finished;

static int enable_slot(struct hotplug_slot *slot);
static int disable_slot(struct hotplug_slot *slot);
static int set_attention_status(struct hotplug_slot *slot, u8 value);
static int get_power_status(struct hotplug_slot *slot, u8 * value);
static int get_attention_status(struct hotplug_slot *slot, u8 * value);
static int get_adapter_status(struct hotplug_slot *slot, u8 * value);
static int get_latch_status(struct hotplug_slot *slot, u8 * value);

static struct hotplug_slot_ops cpci_hotplug_slot_ops = {
	.enable_slot = enable_slot,
	.disable_slot = disable_slot,
	.set_attention_status = set_attention_status,
	.get_power_status = get_power_status,
	.get_attention_status = get_attention_status,
	.get_adapter_status = get_adapter_status,
	.get_latch_status = get_latch_status,
};

static int
update_latch_status(struct hotplug_slot *hotplug_slot, u8 value)
{
	struct hotplug_slot_info info;

	memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info));
	info.latch_status = value;
	return pci_hp_change_slot_info(hotplug_slot, &info);
}

static int
update_adapter_status(struct hotplug_slot *hotplug_slot, u8 value)
{
	struct hotplug_slot_info info;

	memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info));
	info.adapter_status = value;
	return pci_hp_change_slot_info(hotplug_slot, &info);
}

static int
enable_slot(struct hotplug_slot *hotplug_slot)
{
	struct slot *slot = hotplug_slot->private;
	int retval = 0;

	dbg("%s - physical_slot = %s", __func__, slot_name(slot));

	if (controller->ops->set_power)
		retval = controller->ops->set_power(slot, 1);
	return retval;
}

static int
disable_slot(struct hotplug_slot *hotplug_slot)
{
	struct slot *slot = hotplug_slot->private;
	int retval = 0;

	dbg("%s - physical_slot = %s", __func__, slot_name(slot));

	down_write(&list_rwsem);

	/* Unconfigure device */
	dbg("%s - unconfiguring slot %s", __func__, slot_name(slot));
	if ((retval = cpci_unconfigure_slot(slot))) {
		err("%s - could not unconfigure slot %s",
		    __func__, slot_name(slot));
		goto disable_error;
	}
	dbg("%s - finished unconfiguring slot %s", __func__, slot_name(slot));

	/* Clear EXT (by setting it) */
	if (cpci_clear_ext(slot)) {
		err("%s - could not clear EXT for slot %s",
		    __func__, slot_name(slot));
		retval = -ENODEV;
		goto disable_error;
	}
	cpci_led_on(slot);

	if (controller->ops->set_power)
		if ((retval = controller->ops->set_power(slot, 0)))
			goto disable_error;

	if (update_adapter_status(slot->hotplug_slot, 0))
		warn("failure to update adapter file");

	if (slot->extracting) {
		slot->extracting = 0;
		atomic_dec(&extracting);
	}
disable_error:
	up_write(&list_rwsem);
	return retval;
}

static u8
cpci_get_power_status(struct slot *slot)
{
	u8 power = 1;

	if (controller->ops->get_power)
		power = controller->ops->get_power(slot);
	return power;
}

static int
get_power_status(struct hotplug_slot *hotplug_slot, u8 * value)
{
	struct slot *slot = hotplug_slot->private;

	*value = cpci_get_power_status(slot);
	return 0;
}

static int
get_attention_status(struct hotplug_slot *hotplug_slot, u8 * value)
{
	struct slot *slot = hotplug_slot->private;

	*value = cpci_get_attention_status(slot);
	return 0;
}

static int
set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
{
	return cpci_set_attention_status(hotplug_slot->private, status);
}

static int
get_adapter_status(struct hotplug_slot *hotplug_slot, u8 * value)
{
	*value = hotplug_slot->info->adapter_status;
	return 0;
}

static int
get_latch_status(struct hotplug_slot *hotplug_slot, u8 * value)
{
	*value = hotplug_slot->info->latch_status;
	return 0;
}

static void release_slot(struct hotplug_slot *hotplug_slot)
{
	struct slot *slot = hotplug_slot->private;

	kfree(slot->hotplug_slot->info);
	kfree(slot->hotplug_slot);
	if (slot->dev)
		pci_dev_put(slot->dev);
	kfree(slot);
}

#define SLOT_NAME_SIZE	6

int
cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last)
{
	struct slot *slot;
	struct hotplug_slot *hotplug_slot;
	struct hotplug_slot_info *info;
	char name[SLOT_NAME_SIZE];
	int status = -ENOMEM;
	int i;

	if (!(controller && bus))
		return -ENODEV;

	/*
	 * Create a structure for each slot, and register that slot
	 * with the pci_hotplug subsystem.
	 */
	for (i = first; i <= last; ++i) {
		slot = kzalloc(sizeof (struct slot), GFP_KERNEL);
		if (!slot)
			goto error;

		hotplug_slot =
			kzalloc(sizeof (struct hotplug_slot), GFP_KERNEL);
		if (!hotplug_slot)
			goto error_slot;
		slot->hotplug_slot = hotplug_slot;

		info = kzalloc(sizeof (struct hotplug_slot_info), GFP_KERNEL);
		if (!info)
			goto error_hpslot;
		hotplug_slot->info = info;

		slot->bus = bus;
		slot->number = i;
		slot->devfn = PCI_DEVFN(i, 0);

		snprintf(name, SLOT_NAME_SIZE, "%02x:%02x", bus->number, i);

		hotplug_slot->private = slot;
		hotplug_slot->release = &release_slot;
		hotplug_slot->ops = &cpci_hotplug_slot_ops;

		/*
		 * Initialize the slot info structure with some known
		 * good values.
		 */
		dbg("initializing slot %s", name);
		info->power_status = cpci_get_power_status(slot);
		info->attention_status = cpci_get_attention_status(slot);

		dbg("registering slot %s", name);
		status = pci_hp_register(slot->hotplug_slot, bus, i, name);
		if (status) {
			err("pci_hp_register failed with error %d", status);
			goto error_info;
		}
		dbg("slot registered with name: %s", slot_name(slot));

		/* Add slot to our internal list */
		down_write(&list_rwsem);
		list_add(&slot->slot_list, &slot_list);
		slots++;
		up_write(&list_rwsem);
	}
	return 0;
error_info:
	kfree(info);
error_hpslot:
	kfree(hotplug_slot);
error_slot:
	kfree(slot);
error:
	return status;
}

int
cpci_hp_unregister_bus(struct pci_bus *bus)
{
	struct slot *slot;
	struct slot *tmp;
	int status = 0;

	down_write(&list_rwsem);
	if (!slots) {
		up_write(&list_rwsem);
		return -1;
	}
	list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
		if (slot->bus == bus) {
			list_del(&slot->slot_list);
			slots--;

			dbg("deregistering slot %s", slot_name(slot));
			status = pci_hp_deregister(slot->hotplug_slot);
			if (status) {
				err("pci_hp_deregister failed with error %d",
				    status);
				break;
			}
		}
	}
	up_write(&list_rwsem);
	return status;
}

/* This is the interrupt mode interrupt handler */
static irqreturn_t
cpci_hp_intr(int irq, void *data)
{
	dbg("entered cpci_hp_intr");

	/* Check to see if it was our interrupt */
	if ((controller->irq_flags & IRQF_SHARED) &&
	    !controller->ops->check_irq(controller->dev_id)) {
		dbg("exited cpci_hp_intr, not our interrupt");
		return IRQ_NONE;
	}

	/* Disable ENUM interrupt */
	controller->ops->disable_irq();

	/* Trigger processing by the event thread */
	wake_up_process(cpci_thread);
	return IRQ_HANDLED;
}

/*
 * According to PICMG 2.1 R2.0, section 6.3.2, upon
 * initialization, the system driver shall clear the
 * INS bits of the cold-inserted devices.
 */
static int
init_slots(int clear_ins)
{
	struct slot *slot;
	struct pci_dev* dev;

	dbg("%s - enter", __func__);
	down_read(&list_rwsem);
	if (!slots) {
		up_read(&list_rwsem);
		return -1;
	}
	list_for_each_entry(slot, &slot_list, slot_list) {
		dbg("%s - looking at slot %s", __func__, slot_name(slot));
		if (clear_ins && cpci_check_and_clear_ins(slot))
			dbg("%s - cleared INS for slot %s",
			    __func__, slot_name(slot));
		dev = pci_get_slot(slot->bus, PCI_DEVFN(slot->number, 0));
		if (dev) {
			if (update_adapter_status(slot->hotplug_slot, 1))
				warn("failure to update adapter file");
			if (update_latch_status(slot->hotplug_slot, 1))
				warn("failure to update latch file");
			slot->dev = dev;
		}
	}
	up_read(&list_rwsem);
	dbg("%s - exit", __func__);
	return 0;
}

static int
check_slots(void)
{
	struct slot *slot;
	int extracted;
	int inserted;
	u16 hs_csr;

	down_read(&list_rwsem);
	if (!slots) {
		up_read(&list_rwsem);
		err("no slots registered, shutting down");
		return -1;
	}
	extracted = inserted = 0;
	list_for_each_entry(slot, &slot_list, slot_list) {
		dbg("%s - looking at slot %s", __func__, slot_name(slot));
		if (cpci_check_and_clear_ins(slot)) {
			/*
			 * Some broken hardware (e.g. PLX 9054AB) asserts
			 * ENUM# twice...
			 */
			if (slot->dev) {
				warn("slot %s already inserted",
				     slot_name(slot));
				inserted++;
				continue;
			}

			/* Process insertion */
			dbg("%s - slot %s inserted", __func__, slot_name(slot));

			/* GSM, debug */
			hs_csr = cpci_get_hs_csr(slot);
			dbg("%s - slot %s HS_CSR (1) = %04x",
			    __func__, slot_name(slot), hs_csr);

			/* Configure device */
			dbg("%s - configuring slot %s",
			    __func__, slot_name(slot));
			if (cpci_configure_slot(slot)) {
				err("%s - could not configure slot %s",
				    __func__, slot_name(slot));
				continue;
			}
			dbg("%s - finished configuring slot %s",
			    __func__, slot_name(slot));

			/* GSM, debug */
			hs_csr = cpci_get_hs_csr(slot);
			dbg("%s - slot %s HS_CSR (2) = %04x",
			    __func__, slot_name(slot), hs_csr);

			if (update_latch_status(slot->hotplug_slot, 1))
				warn("failure to update latch file");

			if (update_adapter_status(slot->hotplug_slot, 1))
				warn("failure to update adapter file");

			cpci_led_off(slot);

			/* GSM, debug */
			hs_csr = cpci_get_hs_csr(slot);
			dbg("%s - slot %s HS_CSR (3) = %04x",
			    __func__, slot_name(slot), hs_csr);

			inserted++;
		} else if (cpci_check_ext(slot)) {
			/* Process extraction request */
			dbg("%s - slot %s extracted",
			    __func__, slot_name(slot));

			/* GSM, debug */
			hs_csr = cpci_get_hs_csr(slot);
			dbg("%s - slot %s HS_CSR = %04x",
			    __func__, slot_name(slot), hs_csr);

			if (!slot->extracting) {
				if (update_latch_status(slot->hotplug_slot, 0)) {
					warn("failure to update latch file");
				}
				slot->extracting = 1;
				atomic_inc(&extracting);
			}
			extracted++;
		} else if (slot->extracting) {
			hs_csr = cpci_get_hs_csr(slot);
			if (hs_csr == 0xffff) {
				/*
				 * Hmmm, we're likely hosed at this point, should we
				 * bother trying to tell the driver or not?
				 */
				err("card in slot %s was improperly removed",
				    slot_name(slot));
				if (update_adapter_status(slot->hotplug_slot, 0))
					warn("failure to update adapter file");
				slot->extracting = 0;
				atomic_dec(&extracting);
			}
		}
	}
	up_read(&list_rwsem);
	dbg("inserted=%d, extracted=%d, extracting=%d",
	    inserted, extracted, atomic_read(&extracting));
	if (inserted || extracted)
		return extracted;
	else if (!atomic_read(&extracting)) {
		err("cannot find ENUM# source, shutting down");
		return -1;
	}
	return 0;
}

/* This is the interrupt mode worker thread body */
static int
event_thread(void *data)
{
	int rc;

	dbg("%s - event thread started", __func__);
	while (1) {
		dbg("event thread sleeping");
		set_current_state(TASK_INTERRUPTIBLE);
		schedule();
		if (kthread_should_stop())
			break;
		do {
			rc = check_slots();
			if (rc > 0) {
				/* Give userspace a chance to handle extraction */
				msleep(500);
			} else if (rc < 0) {
				dbg("%s - error checking slots", __func__);
				thread_finished = 1;
				goto out;
			}
		} while (atomic_read(&extracting) && !kthread_should_stop());
		if (kthread_should_stop())
			break;

		/* Re-enable ENUM# interrupt */
		dbg("%s - re-enabling irq", __func__);
		controller->ops->enable_irq();
	}
 out:
	return 0;
}

/* This is the polling mode worker thread body */
static int
poll_thread(void *data)
{
	int rc;

	while (1) {
		if (kthread_should_stop() || signal_pending(current))
			break;
		if (controller->ops->query_enum()) {
			do {
				rc = check_slots();
				if (rc > 0) {
					/* Give userspace a chance to handle extraction */
					msleep(500);
				} else if (rc < 0) {
					dbg("%s - error checking slots", __func__);
					thread_finished = 1;
					goto out;
				}
			} while (atomic_read(&extracting) && !kthread_should_stop());
		}
		msleep(100);
	}
 out:
	return 0;
}

static int
cpci_start_thread(void)
{
	if (controller->irq)
		cpci_thread = kthread_run(event_thread, NULL, "cpci_hp_eventd");
	else
		cpci_thread = kthread_run(poll_thread, NULL, "cpci_hp_polld");
	if (IS_ERR(cpci_thread)) {
		err("Can't start up our thread");
		return PTR_ERR(cpci_thread);
	}
	thread_finished = 0;
	return 0;
}

static void
cpci_stop_thread(void)
{
	kthread_stop(cpci_thread);
	thread_finished = 1;
}

int
cpci_hp_register_controller(struct cpci_hp_controller *new_controller)
{
	int status = 0;

	if (controller)
		return -1;
	if (!(new_controller && new_controller->ops))
		return -EINVAL;
	if (new_controller->irq) {
		if (!(new_controller->ops->enable_irq &&
		     new_controller->ops->disable_irq))
			status = -EINVAL;
		if (request_irq(new_controller->irq,
			       cpci_hp_intr,
			       new_controller->irq_flags,
			       MY_NAME,
			       new_controller->dev_id)) {
			err("Can't get irq %d for the hotplug cPCI controller",
			    new_controller->irq);
			status = -ENODEV;
		}
		dbg("%s - acquired controller irq %d",
		    __func__, new_controller->irq);
	}
	if (!status)
		controller = new_controller;
	return status;
}

static void
cleanup_slots(void)
{
	struct slot *slot;
	struct slot *tmp;

	/*
	 * Unregister all of our slots with the pci_hotplug subsystem,
	 * and free up all memory that we had allocated.
	 */
	down_write(&list_rwsem);
	if (!slots)
		goto cleanup_null;
	list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) {
		list_del(&slot->slot_list);
		pci_hp_deregister(slot->hotplug_slot);
	}
cleanup_null:
	up_write(&list_rwsem);
	return;
}

int
cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller)
{
	int status = 0;

	if (controller) {
		if (!thread_finished)
			cpci_stop_thread();
		if (controller->irq)
			free_irq(controller->irq, controller->dev_id);
		controller = NULL;
		cleanup_slots();
	} else
		status = -ENODEV;
	return status;
}

int
cpci_hp_start(void)
{
	static int first = 1;
	int status;

	dbg("%s - enter", __func__);
	if (!controller)
		return -ENODEV;

	down_read(&list_rwsem);
	if (list_empty(&slot_list)) {
		up_read(&list_rwsem);
		return -ENODEV;
	}
	up_read(&list_rwsem);

	status = init_slots(first);
	if (first)
		first = 0;
	if (status)
		return status;

	status = cpci_start_thread();
	if (status)
		return status;
	dbg("%s - thread started", __func__);

	if (controller->irq) {
		/* Start enum interrupt processing */
		dbg("%s - enabling irq", __func__);
		controller->ops->enable_irq();
	}
	dbg("%s - exit", __func__);
	return 0;
}

int
cpci_hp_stop(void)
{
	if (!controller)
		return -ENODEV;
	if (controller->irq) {
		/* Stop enum interrupt processing */
		dbg("%s - disabling irq", __func__);
		controller->ops->disable_irq();
	}
	cpci_stop_thread();
	return 0;
}

int __init
cpci_hotplug_init(int debug)
{
	cpci_debug = debug;
	return 0;
}

void __exit
cpci_hotplug_exit(void)
{
	/*
	 * Clean everything up.
	 */
	cpci_hp_stop();
	cpci_hp_unregister_controller(controller);
}

EXPORT_SYMBOL_GPL(cpci_hp_register_controller);
EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller);
EXPORT_SYMBOL_GPL(cpci_hp_register_bus);
EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus);
EXPORT_SYMBOL_GPL(cpci_hp_start);
EXPORT_SYMBOL_GPL(cpci_hp_stop);