1 /*
2  * PCI Express Hot Plug Controller Driver
3  *
4  * Copyright (C) 1995,2001 Compaq Computer Corporation
5  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
6  * Copyright (C) 2001 IBM Corp.
7  * Copyright (C) 2003-2004 Intel Corporation
8  *
9  * All rights reserved.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or (at
14  * your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
19  * NON INFRINGEMENT.  See the GNU General Public License for more
20  * details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25  *
26  * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
27  *
28  */
29 
30 #include <linux/module.h>
31 #include <linux/kernel.h>
32 #include <linux/types.h>
33 #include <linux/slab.h>
34 #include <linux/pci.h>
35 #include "../pci.h"
36 #include "pciehp.h"
37 
38 static void interrupt_event_handler(struct work_struct *work);
39 
40 static int queue_interrupt_event(struct slot *p_slot, u32 event_type)
41 {
42 	struct event_info *info;
43 
44 	info = kmalloc(sizeof(*info), GFP_ATOMIC);
45 	if (!info)
46 		return -ENOMEM;
47 
48 	info->event_type = event_type;
49 	info->p_slot = p_slot;
50 	INIT_WORK(&info->work, interrupt_event_handler);
51 
52 	queue_work(p_slot->wq, &info->work);
53 
54 	return 0;
55 }
56 
57 u8 pciehp_handle_attention_button(struct slot *p_slot)
58 {
59 	u32 event_type;
60 	struct controller *ctrl = p_slot->ctrl;
61 
62 	/* Attention Button Change */
63 	ctrl_dbg(ctrl, "Attention button interrupt received\n");
64 
65 	/*
66 	 *  Button pressed - See if need to TAKE ACTION!!!
67 	 */
68 	ctrl_info(ctrl, "Button pressed on Slot(%s)\n", slot_name(p_slot));
69 	event_type = INT_BUTTON_PRESS;
70 
71 	queue_interrupt_event(p_slot, event_type);
72 
73 	return 0;
74 }
75 
76 u8 pciehp_handle_switch_change(struct slot *p_slot)
77 {
78 	u8 getstatus;
79 	u32 event_type;
80 	struct controller *ctrl = p_slot->ctrl;
81 
82 	/* Switch Change */
83 	ctrl_dbg(ctrl, "Switch interrupt received\n");
84 
85 	pciehp_get_latch_status(p_slot, &getstatus);
86 	if (getstatus) {
87 		/*
88 		 * Switch opened
89 		 */
90 		ctrl_info(ctrl, "Latch open on Slot(%s)\n", slot_name(p_slot));
91 		event_type = INT_SWITCH_OPEN;
92 	} else {
93 		/*
94 		 *  Switch closed
95 		 */
96 		ctrl_info(ctrl, "Latch close on Slot(%s)\n", slot_name(p_slot));
97 		event_type = INT_SWITCH_CLOSE;
98 	}
99 
100 	queue_interrupt_event(p_slot, event_type);
101 
102 	return 1;
103 }
104 
105 u8 pciehp_handle_presence_change(struct slot *p_slot)
106 {
107 	u32 event_type;
108 	u8 presence_save;
109 	struct controller *ctrl = p_slot->ctrl;
110 
111 	/* Presence Change */
112 	ctrl_dbg(ctrl, "Presence/Notify input change\n");
113 
114 	/* Switch is open, assume a presence change
115 	 * Save the presence state
116 	 */
117 	pciehp_get_adapter_status(p_slot, &presence_save);
118 	if (presence_save) {
119 		/*
120 		 * Card Present
121 		 */
122 		ctrl_info(ctrl, "Card present on Slot(%s)\n", slot_name(p_slot));
123 		event_type = INT_PRESENCE_ON;
124 	} else {
125 		/*
126 		 * Not Present
127 		 */
128 		ctrl_info(ctrl, "Card not present on Slot(%s)\n",
129 			  slot_name(p_slot));
130 		event_type = INT_PRESENCE_OFF;
131 	}
132 
133 	queue_interrupt_event(p_slot, event_type);
134 
135 	return 1;
136 }
137 
138 u8 pciehp_handle_power_fault(struct slot *p_slot)
139 {
140 	u32 event_type;
141 	struct controller *ctrl = p_slot->ctrl;
142 
143 	/* power fault */
144 	ctrl_dbg(ctrl, "Power fault interrupt received\n");
145 	ctrl_err(ctrl, "Power fault on slot %s\n", slot_name(p_slot));
146 	event_type = INT_POWER_FAULT;
147 	ctrl_info(ctrl, "Power fault bit %x set\n", 0);
148 	queue_interrupt_event(p_slot, event_type);
149 
150 	return 1;
151 }
152 
153 void pciehp_handle_linkstate_change(struct slot *p_slot)
154 {
155 	u32 event_type;
156 	struct controller *ctrl = p_slot->ctrl;
157 
158 	/* Link Status Change */
159 	ctrl_dbg(ctrl, "Data Link Layer State change\n");
160 
161 	if (pciehp_check_link_active(ctrl)) {
162 		ctrl_info(ctrl, "slot(%s): Link Up event\n",
163 			  slot_name(p_slot));
164 		event_type = INT_LINK_UP;
165 	} else {
166 		ctrl_info(ctrl, "slot(%s): Link Down event\n",
167 			  slot_name(p_slot));
168 		event_type = INT_LINK_DOWN;
169 	}
170 
171 	queue_interrupt_event(p_slot, event_type);
172 }
173 
174 /* The following routines constitute the bulk of the
175    hotplug controller logic
176  */
177 
178 static void set_slot_off(struct controller *ctrl, struct slot *pslot)
179 {
180 	/* turn off slot, turn on Amber LED, turn off Green LED if supported*/
181 	if (POWER_CTRL(ctrl)) {
182 		pciehp_power_off_slot(pslot);
183 
184 		/*
185 		 * After turning power off, we must wait for at least 1 second
186 		 * before taking any action that relies on power having been
187 		 * removed from the slot/adapter.
188 		 */
189 		msleep(1000);
190 	}
191 
192 	pciehp_green_led_off(pslot);
193 	pciehp_set_attention_status(pslot, 1);
194 }
195 
196 /**
197  * board_added - Called after a board has been added to the system.
198  * @p_slot: &slot where board is added
199  *
200  * Turns power on for the board.
201  * Configures board.
202  */
203 static int board_added(struct slot *p_slot)
204 {
205 	int retval = 0;
206 	struct controller *ctrl = p_slot->ctrl;
207 	struct pci_bus *parent = ctrl->pcie->port->subordinate;
208 
209 	if (POWER_CTRL(ctrl)) {
210 		/* Power on slot */
211 		retval = pciehp_power_on_slot(p_slot);
212 		if (retval)
213 			return retval;
214 	}
215 
216 	pciehp_green_led_blink(p_slot);
217 
218 	/* Check link training status */
219 	retval = pciehp_check_link_status(ctrl);
220 	if (retval) {
221 		ctrl_err(ctrl, "Failed to check link status\n");
222 		goto err_exit;
223 	}
224 
225 	/* Check for a power fault */
226 	if (ctrl->power_fault_detected || pciehp_query_power_fault(p_slot)) {
227 		ctrl_err(ctrl, "Power fault on slot %s\n", slot_name(p_slot));
228 		retval = -EIO;
229 		goto err_exit;
230 	}
231 
232 	retval = pciehp_configure_device(p_slot);
233 	if (retval) {
234 		ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
235 			 pci_domain_nr(parent), parent->number);
236 		if (retval != -EEXIST)
237 			goto err_exit;
238 	}
239 
240 	pciehp_green_led_on(p_slot);
241 	return 0;
242 
243 err_exit:
244 	set_slot_off(ctrl, p_slot);
245 	return retval;
246 }
247 
248 /**
249  * remove_board - Turns off slot and LEDs
250  * @p_slot: slot where board is being removed
251  */
252 static int remove_board(struct slot *p_slot)
253 {
254 	int retval;
255 	struct controller *ctrl = p_slot->ctrl;
256 
257 	retval = pciehp_unconfigure_device(p_slot);
258 	if (retval)
259 		return retval;
260 
261 	if (POWER_CTRL(ctrl)) {
262 		pciehp_power_off_slot(p_slot);
263 
264 		/*
265 		 * After turning power off, we must wait for at least 1 second
266 		 * before taking any action that relies on power having been
267 		 * removed from the slot/adapter.
268 		 */
269 		msleep(1000);
270 	}
271 
272 	/* turn off Green LED */
273 	pciehp_green_led_off(p_slot);
274 	return 0;
275 }
276 
277 struct power_work_info {
278 	struct slot *p_slot;
279 	struct work_struct work;
280 	unsigned int req;
281 #define DISABLE_REQ 0
282 #define ENABLE_REQ  1
283 };
284 
285 /**
286  * pciehp_power_thread - handle pushbutton events
287  * @work: &struct work_struct describing work to be done
288  *
289  * Scheduled procedure to handle blocking stuff for the pushbuttons.
290  * Handles all pending events and exits.
291  */
292 static void pciehp_power_thread(struct work_struct *work)
293 {
294 	struct power_work_info *info =
295 		container_of(work, struct power_work_info, work);
296 	struct slot *p_slot = info->p_slot;
297 	int ret;
298 
299 	switch (info->req) {
300 	case DISABLE_REQ:
301 		ctrl_dbg(p_slot->ctrl,
302 			 "Disabling domain:bus:device=%04x:%02x:00\n",
303 			 pci_domain_nr(p_slot->ctrl->pcie->port->subordinate),
304 			 p_slot->ctrl->pcie->port->subordinate->number);
305 		mutex_lock(&p_slot->hotplug_lock);
306 		pciehp_disable_slot(p_slot);
307 		mutex_unlock(&p_slot->hotplug_lock);
308 		mutex_lock(&p_slot->lock);
309 		p_slot->state = STATIC_STATE;
310 		mutex_unlock(&p_slot->lock);
311 		break;
312 	case ENABLE_REQ:
313 		ctrl_dbg(p_slot->ctrl,
314 			 "Enabling domain:bus:device=%04x:%02x:00\n",
315 			 pci_domain_nr(p_slot->ctrl->pcie->port->subordinate),
316 			 p_slot->ctrl->pcie->port->subordinate->number);
317 		mutex_lock(&p_slot->hotplug_lock);
318 		ret = pciehp_enable_slot(p_slot);
319 		mutex_unlock(&p_slot->hotplug_lock);
320 		if (ret)
321 			pciehp_green_led_off(p_slot);
322 		mutex_lock(&p_slot->lock);
323 		p_slot->state = STATIC_STATE;
324 		mutex_unlock(&p_slot->lock);
325 		break;
326 	default:
327 		break;
328 	}
329 
330 	kfree(info);
331 }
332 
333 void pciehp_queue_pushbutton_work(struct work_struct *work)
334 {
335 	struct slot *p_slot = container_of(work, struct slot, work.work);
336 	struct power_work_info *info;
337 
338 	info = kmalloc(sizeof(*info), GFP_KERNEL);
339 	if (!info) {
340 		ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
341 			 __func__);
342 		return;
343 	}
344 	info->p_slot = p_slot;
345 	INIT_WORK(&info->work, pciehp_power_thread);
346 
347 	mutex_lock(&p_slot->lock);
348 	switch (p_slot->state) {
349 	case BLINKINGOFF_STATE:
350 		p_slot->state = POWEROFF_STATE;
351 		info->req = DISABLE_REQ;
352 		break;
353 	case BLINKINGON_STATE:
354 		p_slot->state = POWERON_STATE;
355 		info->req = ENABLE_REQ;
356 		break;
357 	default:
358 		kfree(info);
359 		goto out;
360 	}
361 	queue_work(p_slot->wq, &info->work);
362  out:
363 	mutex_unlock(&p_slot->lock);
364 }
365 
366 /*
367  * Note: This function must be called with slot->lock held
368  */
369 static void handle_button_press_event(struct slot *p_slot)
370 {
371 	struct controller *ctrl = p_slot->ctrl;
372 	u8 getstatus;
373 
374 	switch (p_slot->state) {
375 	case STATIC_STATE:
376 		pciehp_get_power_status(p_slot, &getstatus);
377 		if (getstatus) {
378 			p_slot->state = BLINKINGOFF_STATE;
379 			ctrl_info(ctrl, "PCI slot #%s - powering off due to button press\n",
380 				  slot_name(p_slot));
381 		} else {
382 			p_slot->state = BLINKINGON_STATE;
383 			ctrl_info(ctrl, "PCI slot #%s - powering on due to button press\n",
384 				  slot_name(p_slot));
385 		}
386 		/* blink green LED and turn off amber */
387 		pciehp_green_led_blink(p_slot);
388 		pciehp_set_attention_status(p_slot, 0);
389 		queue_delayed_work(p_slot->wq, &p_slot->work, 5*HZ);
390 		break;
391 	case BLINKINGOFF_STATE:
392 	case BLINKINGON_STATE:
393 		/*
394 		 * Cancel if we are still blinking; this means that we
395 		 * press the attention again before the 5 sec. limit
396 		 * expires to cancel hot-add or hot-remove
397 		 */
398 		ctrl_info(ctrl, "Button cancel on Slot(%s)\n", slot_name(p_slot));
399 		cancel_delayed_work(&p_slot->work);
400 		if (p_slot->state == BLINKINGOFF_STATE)
401 			pciehp_green_led_on(p_slot);
402 		else
403 			pciehp_green_led_off(p_slot);
404 		pciehp_set_attention_status(p_slot, 0);
405 		ctrl_info(ctrl, "PCI slot #%s - action canceled due to button press\n",
406 			  slot_name(p_slot));
407 		p_slot->state = STATIC_STATE;
408 		break;
409 	case POWEROFF_STATE:
410 	case POWERON_STATE:
411 		/*
412 		 * Ignore if the slot is on power-on or power-off state;
413 		 * this means that the previous attention button action
414 		 * to hot-add or hot-remove is undergoing
415 		 */
416 		ctrl_info(ctrl, "Button ignore on Slot(%s)\n", slot_name(p_slot));
417 		break;
418 	default:
419 		ctrl_warn(ctrl, "Not a valid state\n");
420 		break;
421 	}
422 }
423 
424 /*
425  * Note: This function must be called with slot->lock held
426  */
427 static void handle_surprise_event(struct slot *p_slot)
428 {
429 	u8 getstatus;
430 	struct power_work_info *info;
431 
432 	info = kmalloc(sizeof(*info), GFP_KERNEL);
433 	if (!info) {
434 		ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
435 			 __func__);
436 		return;
437 	}
438 	info->p_slot = p_slot;
439 	INIT_WORK(&info->work, pciehp_power_thread);
440 
441 	pciehp_get_adapter_status(p_slot, &getstatus);
442 	if (!getstatus) {
443 		p_slot->state = POWEROFF_STATE;
444 		info->req = DISABLE_REQ;
445 	} else {
446 		p_slot->state = POWERON_STATE;
447 		info->req = ENABLE_REQ;
448 	}
449 
450 	queue_work(p_slot->wq, &info->work);
451 }
452 
453 /*
454  * Note: This function must be called with slot->lock held
455  */
456 static void handle_link_event(struct slot *p_slot, u32 event)
457 {
458 	struct controller *ctrl = p_slot->ctrl;
459 	struct power_work_info *info;
460 
461 	info = kmalloc(sizeof(*info), GFP_KERNEL);
462 	if (!info) {
463 		ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
464 			 __func__);
465 		return;
466 	}
467 	info->p_slot = p_slot;
468 	info->req = event == INT_LINK_UP ? ENABLE_REQ : DISABLE_REQ;
469 	INIT_WORK(&info->work, pciehp_power_thread);
470 
471 	switch (p_slot->state) {
472 	case BLINKINGON_STATE:
473 	case BLINKINGOFF_STATE:
474 		cancel_delayed_work(&p_slot->work);
475 		/* Fall through */
476 	case STATIC_STATE:
477 		p_slot->state = event == INT_LINK_UP ?
478 		    POWERON_STATE : POWEROFF_STATE;
479 		queue_work(p_slot->wq, &info->work);
480 		break;
481 	case POWERON_STATE:
482 		if (event == INT_LINK_UP) {
483 			ctrl_info(ctrl,
484 				  "Link Up event ignored on slot(%s): already powering on\n",
485 				  slot_name(p_slot));
486 			kfree(info);
487 		} else {
488 			ctrl_info(ctrl,
489 				  "Link Down event queued on slot(%s): currently getting powered on\n",
490 				  slot_name(p_slot));
491 			p_slot->state = POWEROFF_STATE;
492 			queue_work(p_slot->wq, &info->work);
493 		}
494 		break;
495 	case POWEROFF_STATE:
496 		if (event == INT_LINK_UP) {
497 			ctrl_info(ctrl,
498 				  "Link Up event queued on slot(%s): currently getting powered off\n",
499 				  slot_name(p_slot));
500 			p_slot->state = POWERON_STATE;
501 			queue_work(p_slot->wq, &info->work);
502 		} else {
503 			ctrl_info(ctrl,
504 				  "Link Down event ignored on slot(%s): already powering off\n",
505 				  slot_name(p_slot));
506 			kfree(info);
507 		}
508 		break;
509 	default:
510 		ctrl_err(ctrl, "Not a valid state on slot(%s)\n",
511 			 slot_name(p_slot));
512 		kfree(info);
513 		break;
514 	}
515 }
516 
517 static void interrupt_event_handler(struct work_struct *work)
518 {
519 	struct event_info *info = container_of(work, struct event_info, work);
520 	struct slot *p_slot = info->p_slot;
521 	struct controller *ctrl = p_slot->ctrl;
522 
523 	mutex_lock(&p_slot->lock);
524 	switch (info->event_type) {
525 	case INT_BUTTON_PRESS:
526 		handle_button_press_event(p_slot);
527 		break;
528 	case INT_POWER_FAULT:
529 		if (!POWER_CTRL(ctrl))
530 			break;
531 		pciehp_set_attention_status(p_slot, 1);
532 		pciehp_green_led_off(p_slot);
533 		break;
534 	case INT_PRESENCE_ON:
535 		ctrl_dbg(ctrl, "Surprise Insertion\n");
536 		handle_surprise_event(p_slot);
537 		break;
538 	case INT_PRESENCE_OFF:
539 		/*
540 		 * Regardless of surprise capability, we need to
541 		 * definitely remove a card that has been pulled out!
542 		 */
543 		ctrl_dbg(ctrl, "Surprise Removal\n");
544 		handle_surprise_event(p_slot);
545 		break;
546 	case INT_LINK_UP:
547 	case INT_LINK_DOWN:
548 		handle_link_event(p_slot, info->event_type);
549 		break;
550 	default:
551 		break;
552 	}
553 	mutex_unlock(&p_slot->lock);
554 
555 	kfree(info);
556 }
557 
558 /*
559  * Note: This function must be called with slot->hotplug_lock held
560  */
561 int pciehp_enable_slot(struct slot *p_slot)
562 {
563 	u8 getstatus = 0;
564 	int rc;
565 	struct controller *ctrl = p_slot->ctrl;
566 
567 	pciehp_get_adapter_status(p_slot, &getstatus);
568 	if (!getstatus) {
569 		ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
570 		return -ENODEV;
571 	}
572 	if (MRL_SENS(p_slot->ctrl)) {
573 		pciehp_get_latch_status(p_slot, &getstatus);
574 		if (getstatus) {
575 			ctrl_info(ctrl, "Latch open on slot(%s)\n",
576 				  slot_name(p_slot));
577 			return -ENODEV;
578 		}
579 	}
580 
581 	if (POWER_CTRL(p_slot->ctrl)) {
582 		pciehp_get_power_status(p_slot, &getstatus);
583 		if (getstatus) {
584 			ctrl_info(ctrl, "Already enabled on slot(%s)\n",
585 				  slot_name(p_slot));
586 			return -EINVAL;
587 		}
588 	}
589 
590 	pciehp_get_latch_status(p_slot, &getstatus);
591 
592 	rc = board_added(p_slot);
593 	if (rc)
594 		pciehp_get_latch_status(p_slot, &getstatus);
595 
596 	return rc;
597 }
598 
599 /*
600  * Note: This function must be called with slot->hotplug_lock held
601  */
602 int pciehp_disable_slot(struct slot *p_slot)
603 {
604 	u8 getstatus = 0;
605 	struct controller *ctrl = p_slot->ctrl;
606 
607 	if (!p_slot->ctrl)
608 		return 1;
609 
610 	if (POWER_CTRL(p_slot->ctrl)) {
611 		pciehp_get_power_status(p_slot, &getstatus);
612 		if (!getstatus) {
613 			ctrl_info(ctrl, "Already disabled on slot(%s)\n",
614 				  slot_name(p_slot));
615 			return -EINVAL;
616 		}
617 	}
618 
619 	return remove_board(p_slot);
620 }
621 
622 int pciehp_sysfs_enable_slot(struct slot *p_slot)
623 {
624 	int retval = -ENODEV;
625 	struct controller *ctrl = p_slot->ctrl;
626 
627 	mutex_lock(&p_slot->lock);
628 	switch (p_slot->state) {
629 	case BLINKINGON_STATE:
630 		cancel_delayed_work(&p_slot->work);
631 	case STATIC_STATE:
632 		p_slot->state = POWERON_STATE;
633 		mutex_unlock(&p_slot->lock);
634 		mutex_lock(&p_slot->hotplug_lock);
635 		retval = pciehp_enable_slot(p_slot);
636 		mutex_unlock(&p_slot->hotplug_lock);
637 		mutex_lock(&p_slot->lock);
638 		p_slot->state = STATIC_STATE;
639 		break;
640 	case POWERON_STATE:
641 		ctrl_info(ctrl, "Slot %s is already in powering on state\n",
642 			  slot_name(p_slot));
643 		break;
644 	case BLINKINGOFF_STATE:
645 	case POWEROFF_STATE:
646 		ctrl_info(ctrl, "Already enabled on slot %s\n",
647 			  slot_name(p_slot));
648 		break;
649 	default:
650 		ctrl_err(ctrl, "Not a valid state on slot %s\n",
651 			 slot_name(p_slot));
652 		break;
653 	}
654 	mutex_unlock(&p_slot->lock);
655 
656 	return retval;
657 }
658 
659 int pciehp_sysfs_disable_slot(struct slot *p_slot)
660 {
661 	int retval = -ENODEV;
662 	struct controller *ctrl = p_slot->ctrl;
663 
664 	mutex_lock(&p_slot->lock);
665 	switch (p_slot->state) {
666 	case BLINKINGOFF_STATE:
667 		cancel_delayed_work(&p_slot->work);
668 	case STATIC_STATE:
669 		p_slot->state = POWEROFF_STATE;
670 		mutex_unlock(&p_slot->lock);
671 		retval = pciehp_disable_slot(p_slot);
672 		mutex_lock(&p_slot->lock);
673 		p_slot->state = STATIC_STATE;
674 		break;
675 	case POWEROFF_STATE:
676 		ctrl_info(ctrl, "Slot %s is already in powering off state\n",
677 			  slot_name(p_slot));
678 		break;
679 	case BLINKINGON_STATE:
680 	case POWERON_STATE:
681 		ctrl_info(ctrl, "Already disabled on slot %s\n",
682 			  slot_name(p_slot));
683 		break;
684 	default:
685 		ctrl_err(ctrl, "Not a valid state on slot %s\n",
686 			 slot_name(p_slot));
687 		break;
688 	}
689 	mutex_unlock(&p_slot->lock);
690 
691 	return retval;
692 }
693