summaryrefslogtreecommitdiffstats
path: root/drivers/pci/hotplug/pciehp_ctrl.c
blob: 4c8f4cde68540933e0a7c83ac8011bfd68d561e7 (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
/*
 * PCI Express Hot Plug Controller Driver
 *
 * Copyright (C) 1995,2001 Compaq Computer Corporation
 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
 * Copyright (C) 2001 IBM Corp.
 * Copyright (C) 2003-2004 Intel Corporation
 *
 * 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 <greg@kroah.com>, <kristen.c.accardi@intel.com>
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include "../pci.h"
#include "pciehp.h"

static void interrupt_event_handler(struct work_struct *work);

void pciehp_queue_interrupt_event(struct slot *p_slot, u32 event_type)
{
	struct event_info *info;

	info = kmalloc(sizeof(*info), GFP_ATOMIC);
	if (!info) {
		ctrl_err(p_slot->ctrl, "dropped event %d (ENOMEM)\n", event_type);
		return;
	}

	INIT_WORK(&info->work, interrupt_event_handler);
	info->event_type = event_type;
	info->p_slot = p_slot;
	queue_work(p_slot->wq, &info->work);
}

/* The following routines constitute the bulk of the
   hotplug controller logic
 */

static void set_slot_off(struct controller *ctrl, struct slot *pslot)
{
	/* turn off slot, turn on Amber LED, turn off Green LED if supported*/
	if (POWER_CTRL(ctrl)) {
		pciehp_power_off_slot(pslot);

		/*
		 * After turning power off, we must wait for at least 1 second
		 * before taking any action that relies on power having been
		 * removed from the slot/adapter.
		 */
		msleep(1000);
	}

	pciehp_green_led_off(pslot);
	pciehp_set_attention_status(pslot, 1);
}

/**
 * board_added - Called after a board has been added to the system.
 * @p_slot: &slot where board is added
 *
 * Turns power on for the board.
 * Configures board.
 */
static int board_added(struct slot *p_slot)
{
	int retval = 0;
	struct controller *ctrl = p_slot->ctrl;
	struct pci_bus *parent = ctrl->pcie->port->subordinate;

	if (POWER_CTRL(ctrl)) {
		/* Power on slot */
		retval = pciehp_power_on_slot(p_slot);
		if (retval)
			return retval;
	}

	pciehp_green_led_blink(p_slot);

	/* Check link training status */
	retval = pciehp_check_link_status(ctrl);
	if (retval) {
		ctrl_err(ctrl, "Failed to check link status\n");
		goto err_exit;
	}

	/* Check for a power fault */
	if (ctrl->power_fault_detected || pciehp_query_power_fault(p_slot)) {
		ctrl_err(ctrl, "Power fault on slot %s\n", slot_name(p_slot));
		retval = -EIO;
		goto err_exit;
	}

	retval = pciehp_configure_device(p_slot);
	if (retval) {
		ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
			 pci_domain_nr(parent), parent->number);
		if (retval != -EEXIST)
			goto err_exit;
	}

	pciehp_green_led_on(p_slot);
	return 0;

err_exit:
	set_slot_off(ctrl, p_slot);
	return retval;
}

/**
 * remove_board - Turns off slot and LEDs
 * @p_slot: slot where board is being removed
 */
static int remove_board(struct slot *p_slot)
{
	int retval;
	struct controller *ctrl = p_slot->ctrl;

	retval = pciehp_unconfigure_device(p_slot);
	if (retval)
		return retval;

	if (POWER_CTRL(ctrl)) {
		pciehp_power_off_slot(p_slot);

		/*
		 * After turning power off, we must wait for at least 1 second
		 * before taking any action that relies on power having been
		 * removed from the slot/adapter.
		 */
		msleep(1000);
	}

	/* turn off Green LED */
	pciehp_green_led_off(p_slot);
	return 0;
}

struct power_work_info {
	struct slot *p_slot;
	struct work_struct work;
	unsigned int req;
#define DISABLE_REQ 0
#define ENABLE_REQ  1
};

/**
 * pciehp_power_thread - handle pushbutton events
 * @work: &struct work_struct describing work to be done
 *
 * Scheduled procedure to handle blocking stuff for the pushbuttons.
 * Handles all pending events and exits.
 */
static void pciehp_power_thread(struct work_struct *work)
{
	struct power_work_info *info =
		container_of(work, struct power_work_info, work);
	struct slot *p_slot = info->p_slot;
	int ret;

	switch (info->req) {
	case DISABLE_REQ:
		mutex_lock(&p_slot->hotplug_lock);
		pciehp_disable_slot(p_slot);
		mutex_unlock(&p_slot->hotplug_lock);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		mutex_unlock(&p_slot->lock);
		break;
	case ENABLE_REQ:
		mutex_lock(&p_slot->hotplug_lock);
		ret = pciehp_enable_slot(p_slot);
		mutex_unlock(&p_slot->hotplug_lock);
		if (ret)
			pciehp_green_led_off(p_slot);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		mutex_unlock(&p_slot->lock);
		break;
	default:
		break;
	}

	kfree(info);
}

static void pciehp_queue_power_work(struct slot *p_slot, int req)
{
	struct power_work_info *info;

	p_slot->state = (req == ENABLE_REQ) ? POWERON_STATE : POWEROFF_STATE;

	info = kmalloc(sizeof(*info), GFP_KERNEL);
	if (!info) {
		ctrl_err(p_slot->ctrl, "no memory to queue %s request\n",
			 (req == ENABLE_REQ) ? "poweron" : "poweroff");
		return;
	}
	info->p_slot = p_slot;
	INIT_WORK(&info->work, pciehp_power_thread);
	info->req = req;
	queue_work(p_slot->wq, &info->work);
}

void pciehp_queue_pushbutton_work(struct work_struct *work)
{
	struct slot *p_slot = container_of(work, struct slot, work.work);

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case BLINKINGOFF_STATE:
		pciehp_queue_power_work(p_slot, DISABLE_REQ);
		break;
	case BLINKINGON_STATE:
		pciehp_queue_power_work(p_slot, ENABLE_REQ);
		break;
	default:
		break;
	}
	mutex_unlock(&p_slot->lock);
}

/*
 * Note: This function must be called with slot->lock held
 */
static void handle_button_press_event(struct slot *p_slot)
{
	struct controller *ctrl = p_slot->ctrl;
	u8 getstatus;

	switch (p_slot->state) {
	case STATIC_STATE:
		pciehp_get_power_status(p_slot, &getstatus);
		if (getstatus) {
			p_slot->state = BLINKINGOFF_STATE;
			ctrl_info(ctrl, "PCI slot #%s - powering off due to button press\n",
				  slot_name(p_slot));
		} else {
			p_slot->state = BLINKINGON_STATE;
			ctrl_info(ctrl, "PCI slot #%s - powering on due to button press\n",
				  slot_name(p_slot));
		}
		/* blink green LED and turn off amber */
		pciehp_green_led_blink(p_slot);
		pciehp_set_attention_status(p_slot, 0);
		queue_delayed_work(p_slot->wq, &p_slot->work, 5*HZ);
		break;
	case BLINKINGOFF_STATE:
	case BLINKINGON_STATE:
		/*
		 * Cancel if we are still blinking; this means that we
		 * press the attention again before the 5 sec. limit
		 * expires to cancel hot-add or hot-remove
		 */
		ctrl_info(ctrl, "Button cancel on Slot(%s)\n", slot_name(p_slot));
		cancel_delayed_work(&p_slot->work);
		if (p_slot->state == BLINKINGOFF_STATE)
			pciehp_green_led_on(p_slot);
		else
			pciehp_green_led_off(p_slot);
		pciehp_set_attention_status(p_slot, 0);
		ctrl_info(ctrl, "PCI slot #%s - action canceled due to button press\n",
			  slot_name(p_slot));
		p_slot->state = STATIC_STATE;
		break;
	case POWEROFF_STATE:
	case POWERON_STATE:
		/*
		 * Ignore if the slot is on power-on or power-off state;
		 * this means that the previous attention button action
		 * to hot-add or hot-remove is undergoing
		 */
		ctrl_info(ctrl, "Button ignore on Slot(%s)\n", slot_name(p_slot));
		break;
	default:
		ctrl_warn(ctrl, "ignoring invalid state %#x\n", p_slot->state);
		break;
	}
}

/*
 * Note: This function must be called with slot->lock held
 */
static void handle_surprise_event(struct slot *p_slot)
{
	u8 getstatus;

	pciehp_get_adapter_status(p_slot, &getstatus);
	if (!getstatus)
		pciehp_queue_power_work(p_slot, DISABLE_REQ);
	else
		pciehp_queue_power_work(p_slot, ENABLE_REQ);
}

/*
 * Note: This function must be called with slot->lock held
 */
static void handle_link_event(struct slot *p_slot, u32 event)
{
	struct controller *ctrl = p_slot->ctrl;

	switch (p_slot->state) {
	case BLINKINGON_STATE:
	case BLINKINGOFF_STATE:
		cancel_delayed_work(&p_slot->work);
		/* Fall through */
	case STATIC_STATE:
		pciehp_queue_power_work(p_slot, event == INT_LINK_UP ?
					ENABLE_REQ : DISABLE_REQ);
		break;
	case POWERON_STATE:
		if (event == INT_LINK_UP) {
			ctrl_info(ctrl,
				  "Link Up event ignored on slot(%s): already powering on\n",
				  slot_name(p_slot));
		} else {
			ctrl_info(ctrl,
				  "Link Down event queued on slot(%s): currently getting powered on\n",
				  slot_name(p_slot));
			pciehp_queue_power_work(p_slot, DISABLE_REQ);
		}
		break;
	case POWEROFF_STATE:
		if (event == INT_LINK_UP) {
			ctrl_info(ctrl,
				  "Link Up event queued on slot(%s): currently getting powered off\n",
				  slot_name(p_slot));
			pciehp_queue_power_work(p_slot, ENABLE_REQ);
		} else {
			ctrl_info(ctrl,
				  "Link Down event ignored on slot(%s): already powering off\n",
				  slot_name(p_slot));
		}
		break;
	default:
		ctrl_err(ctrl, "ignoring invalid state %#x on slot(%s)\n",
			 p_slot->state, slot_name(p_slot));
		break;
	}
}

static void interrupt_event_handler(struct work_struct *work)
{
	struct event_info *info = container_of(work, struct event_info, work);
	struct slot *p_slot = info->p_slot;
	struct controller *ctrl = p_slot->ctrl;

	mutex_lock(&p_slot->lock);
	switch (info->event_type) {
	case INT_BUTTON_PRESS:
		handle_button_press_event(p_slot);
		break;
	case INT_POWER_FAULT:
		if (!POWER_CTRL(ctrl))
			break;
		pciehp_set_attention_status(p_slot, 1);
		pciehp_green_led_off(p_slot);
		break;
	case INT_PRESENCE_ON:
		handle_surprise_event(p_slot);
		break;
	case INT_PRESENCE_OFF:
		/*
		 * Regardless of surprise capability, we need to
		 * definitely remove a card that has been pulled out!
		 */
		handle_surprise_event(p_slot);
		break;
	case INT_LINK_UP:
	case INT_LINK_DOWN:
		handle_link_event(p_slot, info->event_type);
		break;
	default:
		break;
	}
	mutex_unlock(&p_slot->lock);

	kfree(info);
}

/*
 * Note: This function must be called with slot->hotplug_lock held
 */
int pciehp_enable_slot(struct slot *p_slot)
{
	u8 getstatus = 0;
	int rc;
	struct controller *ctrl = p_slot->ctrl;

	pciehp_get_adapter_status(p_slot, &getstatus);
	if (!getstatus) {
		ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
		return -ENODEV;
	}
	if (MRL_SENS(p_slot->ctrl)) {
		pciehp_get_latch_status(p_slot, &getstatus);
		if (getstatus) {
			ctrl_info(ctrl, "Latch open on slot(%s)\n",
				  slot_name(p_slot));
			return -ENODEV;
		}
	}

	if (POWER_CTRL(p_slot->ctrl)) {
		pciehp_get_power_status(p_slot, &getstatus);
		if (getstatus) {
			ctrl_info(ctrl, "Already enabled on slot(%s)\n",
				  slot_name(p_slot));
			return -EINVAL;
		}
	}

	pciehp_get_latch_status(p_slot, &getstatus);

	rc = board_added(p_slot);
	if (rc)
		pciehp_get_latch_status(p_slot, &getstatus);

	return rc;
}

/*
 * Note: This function must be called with slot->hotplug_lock held
 */
int pciehp_disable_slot(struct slot *p_slot)
{
	u8 getstatus = 0;
	struct controller *ctrl = p_slot->ctrl;

	if (!p_slot->ctrl)
		return 1;

	if (POWER_CTRL(p_slot->ctrl)) {
		pciehp_get_power_status(p_slot, &getstatus);
		if (!getstatus) {
			ctrl_info(ctrl, "Already disabled on slot(%s)\n",
				  slot_name(p_slot));
			return -EINVAL;
		}
	}

	return remove_board(p_slot);
}

int pciehp_sysfs_enable_slot(struct slot *p_slot)
{
	int retval = -ENODEV;
	struct controller *ctrl = p_slot->ctrl;

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case BLINKINGON_STATE:
		cancel_delayed_work(&p_slot->work);
	case STATIC_STATE:
		p_slot->state = POWERON_STATE;
		mutex_unlock(&p_slot->lock);
		mutex_lock(&p_slot->hotplug_lock);
		retval = pciehp_enable_slot(p_slot);
		mutex_unlock(&p_slot->hotplug_lock);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		break;
	case POWERON_STATE:
		ctrl_info(ctrl, "Slot %s is already in powering on state\n",
			  slot_name(p_slot));
		break;
	case BLINKINGOFF_STATE:
	case POWEROFF_STATE:
		ctrl_info(ctrl, "Already enabled on slot %s\n",
			  slot_name(p_slot));
		break;
	default:
		ctrl_err(ctrl, "invalid state %#x on slot %s\n",
			 p_slot->state, slot_name(p_slot));
		break;
	}
	mutex_unlock(&p_slot->lock);

	return retval;
}

int pciehp_sysfs_disable_slot(struct slot *p_slot)
{
	int retval = -ENODEV;
	struct controller *ctrl = p_slot->ctrl;

	mutex_lock(&p_slot->lock);
	switch (p_slot->state) {
	case BLINKINGOFF_STATE:
		cancel_delayed_work(&p_slot->work);
	case STATIC_STATE:
		p_slot->state = POWEROFF_STATE;
		mutex_unlock(&p_slot->lock);
		retval = pciehp_disable_slot(p_slot);
		mutex_lock(&p_slot->lock);
		p_slot->state = STATIC_STATE;
		break;
	case POWEROFF_STATE:
		ctrl_info(ctrl, "Slot %s is already in powering off state\n",
			  slot_name(p_slot));
		break;
	case BLINKINGON_STATE:
	case POWERON_STATE:
		ctrl_info(ctrl, "Already disabled on slot %s\n",
			  slot_name(p_slot));
		break;
	default:
		ctrl_err(ctrl, "invalid state %#x on slot %s\n",
			 p_slot->state, slot_name(p_slot));
		break;
	}
	mutex_unlock(&p_slot->lock);

	return retval;
}
OpenPOWER on IntegriCloud