xref: /linux/drivers/pci/hotplug/pciehp_ctrl.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 void pciehp_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 		ctrl_err(p_slot->ctrl, "dropped event %d (ENOMEM)\n", event_type);
47 		return;
48 	}
49 
50 	INIT_WORK(&info->work, interrupt_event_handler);
51 	info->event_type = event_type;
52 	info->p_slot = p_slot;
53 	queue_work(p_slot->wq, &info->work);
54 }
55 
56 /* The following routines constitute the bulk of the
57    hotplug controller logic
58  */
59 
60 static void set_slot_off(struct controller *ctrl, struct slot *pslot)
61 {
62 	/* turn off slot, turn on Amber LED, turn off Green LED if supported*/
63 	if (POWER_CTRL(ctrl)) {
64 		pciehp_power_off_slot(pslot);
65 
66 		/*
67 		 * After turning power off, we must wait for at least 1 second
68 		 * before taking any action that relies on power having been
69 		 * removed from the slot/adapter.
70 		 */
71 		msleep(1000);
72 	}
73 
74 	pciehp_green_led_off(pslot);
75 	pciehp_set_attention_status(pslot, 1);
76 }
77 
78 /**
79  * board_added - Called after a board has been added to the system.
80  * @p_slot: &slot where board is added
81  *
82  * Turns power on for the board.
83  * Configures board.
84  */
85 static int board_added(struct slot *p_slot)
86 {
87 	int retval = 0;
88 	struct controller *ctrl = p_slot->ctrl;
89 	struct pci_bus *parent = ctrl->pcie->port->subordinate;
90 
91 	if (POWER_CTRL(ctrl)) {
92 		/* Power on slot */
93 		retval = pciehp_power_on_slot(p_slot);
94 		if (retval)
95 			return retval;
96 	}
97 
98 	pciehp_green_led_blink(p_slot);
99 
100 	/* Check link training status */
101 	retval = pciehp_check_link_status(ctrl);
102 	if (retval) {
103 		ctrl_err(ctrl, "Failed to check link status\n");
104 		goto err_exit;
105 	}
106 
107 	/* Check for a power fault */
108 	if (ctrl->power_fault_detected || pciehp_query_power_fault(p_slot)) {
109 		ctrl_err(ctrl, "Power fault on slot %s\n", slot_name(p_slot));
110 		retval = -EIO;
111 		goto err_exit;
112 	}
113 
114 	retval = pciehp_configure_device(p_slot);
115 	if (retval) {
116 		ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
117 			 pci_domain_nr(parent), parent->number);
118 		if (retval != -EEXIST)
119 			goto err_exit;
120 	}
121 
122 	pciehp_green_led_on(p_slot);
123 	return 0;
124 
125 err_exit:
126 	set_slot_off(ctrl, p_slot);
127 	return retval;
128 }
129 
130 /**
131  * remove_board - Turns off slot and LEDs
132  * @p_slot: slot where board is being removed
133  */
134 static int remove_board(struct slot *p_slot)
135 {
136 	int retval;
137 	struct controller *ctrl = p_slot->ctrl;
138 
139 	retval = pciehp_unconfigure_device(p_slot);
140 	if (retval)
141 		return retval;
142 
143 	if (POWER_CTRL(ctrl)) {
144 		pciehp_power_off_slot(p_slot);
145 
146 		/*
147 		 * After turning power off, we must wait for at least 1 second
148 		 * before taking any action that relies on power having been
149 		 * removed from the slot/adapter.
150 		 */
151 		msleep(1000);
152 	}
153 
154 	/* turn off Green LED */
155 	pciehp_green_led_off(p_slot);
156 	return 0;
157 }
158 
159 struct power_work_info {
160 	struct slot *p_slot;
161 	struct work_struct work;
162 	unsigned int req;
163 #define DISABLE_REQ 0
164 #define ENABLE_REQ  1
165 };
166 
167 /**
168  * pciehp_power_thread - handle pushbutton events
169  * @work: &struct work_struct describing work to be done
170  *
171  * Scheduled procedure to handle blocking stuff for the pushbuttons.
172  * Handles all pending events and exits.
173  */
174 static void pciehp_power_thread(struct work_struct *work)
175 {
176 	struct power_work_info *info =
177 		container_of(work, struct power_work_info, work);
178 	struct slot *p_slot = info->p_slot;
179 	int ret;
180 
181 	switch (info->req) {
182 	case DISABLE_REQ:
183 		mutex_lock(&p_slot->hotplug_lock);
184 		pciehp_disable_slot(p_slot);
185 		mutex_unlock(&p_slot->hotplug_lock);
186 		mutex_lock(&p_slot->lock);
187 		p_slot->state = STATIC_STATE;
188 		mutex_unlock(&p_slot->lock);
189 		break;
190 	case ENABLE_REQ:
191 		mutex_lock(&p_slot->hotplug_lock);
192 		ret = pciehp_enable_slot(p_slot);
193 		mutex_unlock(&p_slot->hotplug_lock);
194 		if (ret)
195 			pciehp_green_led_off(p_slot);
196 		mutex_lock(&p_slot->lock);
197 		p_slot->state = STATIC_STATE;
198 		mutex_unlock(&p_slot->lock);
199 		break;
200 	default:
201 		break;
202 	}
203 
204 	kfree(info);
205 }
206 
207 void pciehp_queue_pushbutton_work(struct work_struct *work)
208 {
209 	struct slot *p_slot = container_of(work, struct slot, work.work);
210 	struct power_work_info *info;
211 
212 	info = kmalloc(sizeof(*info), GFP_KERNEL);
213 	if (!info) {
214 		ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
215 			 __func__);
216 		return;
217 	}
218 	info->p_slot = p_slot;
219 	INIT_WORK(&info->work, pciehp_power_thread);
220 
221 	mutex_lock(&p_slot->lock);
222 	switch (p_slot->state) {
223 	case BLINKINGOFF_STATE:
224 		p_slot->state = POWEROFF_STATE;
225 		info->req = DISABLE_REQ;
226 		break;
227 	case BLINKINGON_STATE:
228 		p_slot->state = POWERON_STATE;
229 		info->req = ENABLE_REQ;
230 		break;
231 	default:
232 		kfree(info);
233 		goto out;
234 	}
235 	queue_work(p_slot->wq, &info->work);
236  out:
237 	mutex_unlock(&p_slot->lock);
238 }
239 
240 /*
241  * Note: This function must be called with slot->lock held
242  */
243 static void handle_button_press_event(struct slot *p_slot)
244 {
245 	struct controller *ctrl = p_slot->ctrl;
246 	u8 getstatus;
247 
248 	switch (p_slot->state) {
249 	case STATIC_STATE:
250 		pciehp_get_power_status(p_slot, &getstatus);
251 		if (getstatus) {
252 			p_slot->state = BLINKINGOFF_STATE;
253 			ctrl_info(ctrl, "PCI slot #%s - powering off due to button press\n",
254 				  slot_name(p_slot));
255 		} else {
256 			p_slot->state = BLINKINGON_STATE;
257 			ctrl_info(ctrl, "PCI slot #%s - powering on due to button press\n",
258 				  slot_name(p_slot));
259 		}
260 		/* blink green LED and turn off amber */
261 		pciehp_green_led_blink(p_slot);
262 		pciehp_set_attention_status(p_slot, 0);
263 		queue_delayed_work(p_slot->wq, &p_slot->work, 5*HZ);
264 		break;
265 	case BLINKINGOFF_STATE:
266 	case BLINKINGON_STATE:
267 		/*
268 		 * Cancel if we are still blinking; this means that we
269 		 * press the attention again before the 5 sec. limit
270 		 * expires to cancel hot-add or hot-remove
271 		 */
272 		ctrl_info(ctrl, "Button cancel on Slot(%s)\n", slot_name(p_slot));
273 		cancel_delayed_work(&p_slot->work);
274 		if (p_slot->state == BLINKINGOFF_STATE)
275 			pciehp_green_led_on(p_slot);
276 		else
277 			pciehp_green_led_off(p_slot);
278 		pciehp_set_attention_status(p_slot, 0);
279 		ctrl_info(ctrl, "PCI slot #%s - action canceled due to button press\n",
280 			  slot_name(p_slot));
281 		p_slot->state = STATIC_STATE;
282 		break;
283 	case POWEROFF_STATE:
284 	case POWERON_STATE:
285 		/*
286 		 * Ignore if the slot is on power-on or power-off state;
287 		 * this means that the previous attention button action
288 		 * to hot-add or hot-remove is undergoing
289 		 */
290 		ctrl_info(ctrl, "Button ignore on Slot(%s)\n", slot_name(p_slot));
291 		break;
292 	default:
293 		ctrl_warn(ctrl, "ignoring invalid state %#x\n", p_slot->state);
294 		break;
295 	}
296 }
297 
298 /*
299  * Note: This function must be called with slot->lock held
300  */
301 static void handle_surprise_event(struct slot *p_slot)
302 {
303 	u8 getstatus;
304 	struct power_work_info *info;
305 
306 	info = kmalloc(sizeof(*info), GFP_KERNEL);
307 	if (!info) {
308 		ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
309 			 __func__);
310 		return;
311 	}
312 	info->p_slot = p_slot;
313 	INIT_WORK(&info->work, pciehp_power_thread);
314 
315 	pciehp_get_adapter_status(p_slot, &getstatus);
316 	if (!getstatus) {
317 		p_slot->state = POWEROFF_STATE;
318 		info->req = DISABLE_REQ;
319 	} else {
320 		p_slot->state = POWERON_STATE;
321 		info->req = ENABLE_REQ;
322 	}
323 
324 	queue_work(p_slot->wq, &info->work);
325 }
326 
327 /*
328  * Note: This function must be called with slot->lock held
329  */
330 static void handle_link_event(struct slot *p_slot, u32 event)
331 {
332 	struct controller *ctrl = p_slot->ctrl;
333 	struct power_work_info *info;
334 
335 	info = kmalloc(sizeof(*info), GFP_KERNEL);
336 	if (!info) {
337 		ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
338 			 __func__);
339 		return;
340 	}
341 	info->p_slot = p_slot;
342 	info->req = event == INT_LINK_UP ? ENABLE_REQ : DISABLE_REQ;
343 	INIT_WORK(&info->work, pciehp_power_thread);
344 
345 	switch (p_slot->state) {
346 	case BLINKINGON_STATE:
347 	case BLINKINGOFF_STATE:
348 		cancel_delayed_work(&p_slot->work);
349 		/* Fall through */
350 	case STATIC_STATE:
351 		p_slot->state = event == INT_LINK_UP ?
352 		    POWERON_STATE : POWEROFF_STATE;
353 		queue_work(p_slot->wq, &info->work);
354 		break;
355 	case POWERON_STATE:
356 		if (event == INT_LINK_UP) {
357 			ctrl_info(ctrl,
358 				  "Link Up event ignored on slot(%s): already powering on\n",
359 				  slot_name(p_slot));
360 			kfree(info);
361 		} else {
362 			ctrl_info(ctrl,
363 				  "Link Down event queued on slot(%s): currently getting powered on\n",
364 				  slot_name(p_slot));
365 			p_slot->state = POWEROFF_STATE;
366 			queue_work(p_slot->wq, &info->work);
367 		}
368 		break;
369 	case POWEROFF_STATE:
370 		if (event == INT_LINK_UP) {
371 			ctrl_info(ctrl,
372 				  "Link Up event queued on slot(%s): currently getting powered off\n",
373 				  slot_name(p_slot));
374 			p_slot->state = POWERON_STATE;
375 			queue_work(p_slot->wq, &info->work);
376 		} else {
377 			ctrl_info(ctrl,
378 				  "Link Down event ignored on slot(%s): already powering off\n",
379 				  slot_name(p_slot));
380 			kfree(info);
381 		}
382 		break;
383 	default:
384 		ctrl_err(ctrl, "ignoring invalid state %#x on slot(%s)\n",
385 			 p_slot->state, slot_name(p_slot));
386 		kfree(info);
387 		break;
388 	}
389 }
390 
391 static void interrupt_event_handler(struct work_struct *work)
392 {
393 	struct event_info *info = container_of(work, struct event_info, work);
394 	struct slot *p_slot = info->p_slot;
395 	struct controller *ctrl = p_slot->ctrl;
396 
397 	mutex_lock(&p_slot->lock);
398 	switch (info->event_type) {
399 	case INT_BUTTON_PRESS:
400 		handle_button_press_event(p_slot);
401 		break;
402 	case INT_POWER_FAULT:
403 		if (!POWER_CTRL(ctrl))
404 			break;
405 		pciehp_set_attention_status(p_slot, 1);
406 		pciehp_green_led_off(p_slot);
407 		break;
408 	case INT_PRESENCE_ON:
409 		handle_surprise_event(p_slot);
410 		break;
411 	case INT_PRESENCE_OFF:
412 		/*
413 		 * Regardless of surprise capability, we need to
414 		 * definitely remove a card that has been pulled out!
415 		 */
416 		handle_surprise_event(p_slot);
417 		break;
418 	case INT_LINK_UP:
419 	case INT_LINK_DOWN:
420 		handle_link_event(p_slot, info->event_type);
421 		break;
422 	default:
423 		break;
424 	}
425 	mutex_unlock(&p_slot->lock);
426 
427 	kfree(info);
428 }
429 
430 /*
431  * Note: This function must be called with slot->hotplug_lock held
432  */
433 int pciehp_enable_slot(struct slot *p_slot)
434 {
435 	u8 getstatus = 0;
436 	int rc;
437 	struct controller *ctrl = p_slot->ctrl;
438 
439 	pciehp_get_adapter_status(p_slot, &getstatus);
440 	if (!getstatus) {
441 		ctrl_info(ctrl, "No adapter on slot(%s)\n", slot_name(p_slot));
442 		return -ENODEV;
443 	}
444 	if (MRL_SENS(p_slot->ctrl)) {
445 		pciehp_get_latch_status(p_slot, &getstatus);
446 		if (getstatus) {
447 			ctrl_info(ctrl, "Latch open on slot(%s)\n",
448 				  slot_name(p_slot));
449 			return -ENODEV;
450 		}
451 	}
452 
453 	if (POWER_CTRL(p_slot->ctrl)) {
454 		pciehp_get_power_status(p_slot, &getstatus);
455 		if (getstatus) {
456 			ctrl_info(ctrl, "Already enabled on slot(%s)\n",
457 				  slot_name(p_slot));
458 			return -EINVAL;
459 		}
460 	}
461 
462 	pciehp_get_latch_status(p_slot, &getstatus);
463 
464 	rc = board_added(p_slot);
465 	if (rc)
466 		pciehp_get_latch_status(p_slot, &getstatus);
467 
468 	return rc;
469 }
470 
471 /*
472  * Note: This function must be called with slot->hotplug_lock held
473  */
474 int pciehp_disable_slot(struct slot *p_slot)
475 {
476 	u8 getstatus = 0;
477 	struct controller *ctrl = p_slot->ctrl;
478 
479 	if (!p_slot->ctrl)
480 		return 1;
481 
482 	if (POWER_CTRL(p_slot->ctrl)) {
483 		pciehp_get_power_status(p_slot, &getstatus);
484 		if (!getstatus) {
485 			ctrl_info(ctrl, "Already disabled on slot(%s)\n",
486 				  slot_name(p_slot));
487 			return -EINVAL;
488 		}
489 	}
490 
491 	return remove_board(p_slot);
492 }
493 
494 int pciehp_sysfs_enable_slot(struct slot *p_slot)
495 {
496 	int retval = -ENODEV;
497 	struct controller *ctrl = p_slot->ctrl;
498 
499 	mutex_lock(&p_slot->lock);
500 	switch (p_slot->state) {
501 	case BLINKINGON_STATE:
502 		cancel_delayed_work(&p_slot->work);
503 	case STATIC_STATE:
504 		p_slot->state = POWERON_STATE;
505 		mutex_unlock(&p_slot->lock);
506 		mutex_lock(&p_slot->hotplug_lock);
507 		retval = pciehp_enable_slot(p_slot);
508 		mutex_unlock(&p_slot->hotplug_lock);
509 		mutex_lock(&p_slot->lock);
510 		p_slot->state = STATIC_STATE;
511 		break;
512 	case POWERON_STATE:
513 		ctrl_info(ctrl, "Slot %s is already in powering on state\n",
514 			  slot_name(p_slot));
515 		break;
516 	case BLINKINGOFF_STATE:
517 	case POWEROFF_STATE:
518 		ctrl_info(ctrl, "Already enabled on slot %s\n",
519 			  slot_name(p_slot));
520 		break;
521 	default:
522 		ctrl_err(ctrl, "invalid state %#x on slot %s\n",
523 			 p_slot->state, slot_name(p_slot));
524 		break;
525 	}
526 	mutex_unlock(&p_slot->lock);
527 
528 	return retval;
529 }
530 
531 int pciehp_sysfs_disable_slot(struct slot *p_slot)
532 {
533 	int retval = -ENODEV;
534 	struct controller *ctrl = p_slot->ctrl;
535 
536 	mutex_lock(&p_slot->lock);
537 	switch (p_slot->state) {
538 	case BLINKINGOFF_STATE:
539 		cancel_delayed_work(&p_slot->work);
540 	case STATIC_STATE:
541 		p_slot->state = POWEROFF_STATE;
542 		mutex_unlock(&p_slot->lock);
543 		retval = pciehp_disable_slot(p_slot);
544 		mutex_lock(&p_slot->lock);
545 		p_slot->state = STATIC_STATE;
546 		break;
547 	case POWEROFF_STATE:
548 		ctrl_info(ctrl, "Slot %s is already in powering off state\n",
549 			  slot_name(p_slot));
550 		break;
551 	case BLINKINGON_STATE:
552 	case POWERON_STATE:
553 		ctrl_info(ctrl, "Already disabled on slot %s\n",
554 			  slot_name(p_slot));
555 		break;
556 	default:
557 		ctrl_err(ctrl, "invalid state %#x on slot %s\n",
558 			 p_slot->state, slot_name(p_slot));
559 		break;
560 	}
561 	mutex_unlock(&p_slot->lock);
562 
563 	return retval;
564 }
565