xref: /openbmc/linux/drivers/misc/mei/interrupt.c (revision 94cdda6b)
1 /*
2  *
3  * Intel Management Engine Interface (Intel MEI) Linux driver
4  * Copyright (c) 2003-2012, Intel Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  */
16 
17 
18 #include <linux/export.h>
19 #include <linux/kthread.h>
20 #include <linux/interrupt.h>
21 #include <linux/fs.h>
22 #include <linux/jiffies.h>
23 #include <linux/slab.h>
24 
25 #include <linux/mei.h>
26 
27 #include "mei_dev.h"
28 #include "hbm.h"
29 #include "client.h"
30 
31 
32 /**
33  * mei_irq_compl_handler - dispatch complete handlers
34  *	for the completed callbacks
35  *
36  * @dev: mei device
37  * @compl_list: list of completed cbs
38  */
39 void mei_irq_compl_handler(struct mei_device *dev, struct mei_cl_cb *compl_list)
40 {
41 	struct mei_cl_cb *cb, *next;
42 	struct mei_cl *cl;
43 
44 	list_for_each_entry_safe(cb, next, &compl_list->list, list) {
45 		cl = cb->cl;
46 		list_del_init(&cb->list);
47 
48 		dev_dbg(dev->dev, "completing call back.\n");
49 		if (cl == &dev->iamthif_cl)
50 			mei_amthif_complete(dev, cb);
51 		else
52 			mei_cl_complete(cl, cb);
53 	}
54 }
55 EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
56 
57 /**
58  * mei_cl_hbm_equal - check if hbm is addressed to the client
59  *
60  * @cl: host client
61  * @mei_hdr: header of mei client message
62  *
63  * Return: true if matches, false otherwise
64  */
65 static inline int mei_cl_hbm_equal(struct mei_cl *cl,
66 			struct mei_msg_hdr *mei_hdr)
67 {
68 	return cl->host_client_id == mei_hdr->host_addr &&
69 		cl->me_client_id == mei_hdr->me_addr;
70 }
71 
72 /**
73  * mei_irq_discard_msg  - discard received message
74  *
75  * @dev: mei device
76  * @hdr: message header
77  */
78 static inline
79 void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr)
80 {
81 	/*
82 	 * no need to check for size as it is guarantied
83 	 * that length fits into rd_msg_buf
84 	 */
85 	mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
86 	dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
87 		MEI_HDR_PRM(hdr));
88 }
89 
90 /**
91  * mei_cl_irq_read_msg - process client message
92  *
93  * @cl: reading client
94  * @mei_hdr: header of mei client message
95  * @complete_list: completion list
96  *
97  * Return: always 0
98  */
99 int mei_cl_irq_read_msg(struct mei_cl *cl,
100 		       struct mei_msg_hdr *mei_hdr,
101 		       struct mei_cl_cb *complete_list)
102 {
103 	struct mei_device *dev = cl->dev;
104 	struct mei_cl_cb *cb;
105 	unsigned char *buffer = NULL;
106 
107 	cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
108 	if (!cb) {
109 		cl_err(dev, cl, "pending read cb not found\n");
110 		goto out;
111 	}
112 
113 	if (!mei_cl_is_connected(cl)) {
114 		cl_dbg(dev, cl, "not connected\n");
115 		cb->status = -ENODEV;
116 		goto out;
117 	}
118 
119 	if (cb->buf.size == 0 || cb->buf.data == NULL) {
120 		cl_err(dev, cl, "response buffer is not allocated.\n");
121 		list_move_tail(&cb->list, &complete_list->list);
122 		cb->status = -ENOMEM;
123 		goto out;
124 	}
125 
126 	if (cb->buf.size < mei_hdr->length + cb->buf_idx) {
127 		cl_dbg(dev, cl, "message overflow. size %d len %d idx %ld\n",
128 			cb->buf.size, mei_hdr->length, cb->buf_idx);
129 		buffer = krealloc(cb->buf.data, mei_hdr->length + cb->buf_idx,
130 				  GFP_KERNEL);
131 
132 		if (!buffer) {
133 			cb->status = -ENOMEM;
134 			list_move_tail(&cb->list, &complete_list->list);
135 			goto out;
136 		}
137 		cb->buf.data = buffer;
138 		cb->buf.size = mei_hdr->length + cb->buf_idx;
139 	}
140 
141 	buffer = cb->buf.data + cb->buf_idx;
142 	mei_read_slots(dev, buffer, mei_hdr->length);
143 
144 	cb->buf_idx += mei_hdr->length;
145 
146 	if (mei_hdr->msg_complete) {
147 		cb->read_time = jiffies;
148 		cl_dbg(dev, cl, "completed read length = %lu\n", cb->buf_idx);
149 		list_move_tail(&cb->list, &complete_list->list);
150 	}
151 
152 out:
153 	if (!buffer)
154 		mei_irq_discard_msg(dev, mei_hdr);
155 
156 	return 0;
157 }
158 
159 /**
160  * mei_cl_irq_disconnect_rsp - send disconnection response message
161  *
162  * @cl: client
163  * @cb: callback block.
164  * @cmpl_list: complete list.
165  *
166  * Return: 0, OK; otherwise, error.
167  */
168 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
169 				     struct mei_cl_cb *cmpl_list)
170 {
171 	struct mei_device *dev = cl->dev;
172 	u32 msg_slots;
173 	int slots;
174 	int ret;
175 
176 	slots = mei_hbuf_empty_slots(dev);
177 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_response));
178 
179 	if (slots < msg_slots)
180 		return -EMSGSIZE;
181 
182 	ret = mei_hbm_cl_disconnect_rsp(dev, cl);
183 
184 	cl->state = MEI_FILE_DISCONNECTED;
185 	cl->status = 0;
186 	mei_io_cb_free(cb);
187 
188 	return ret;
189 }
190 
191 
192 
193 /**
194  * mei_cl_irq_disconnect - processes close related operation from
195  *	interrupt thread context - send disconnect request
196  *
197  * @cl: client
198  * @cb: callback block.
199  * @cmpl_list: complete list.
200  *
201  * Return: 0, OK; otherwise, error.
202  */
203 static int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
204 			    struct mei_cl_cb *cmpl_list)
205 {
206 	struct mei_device *dev = cl->dev;
207 	u32 msg_slots;
208 	int slots;
209 
210 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
211 	slots = mei_hbuf_empty_slots(dev);
212 
213 	if (slots < msg_slots)
214 		return -EMSGSIZE;
215 
216 	if (mei_hbm_cl_disconnect_req(dev, cl)) {
217 		cl->status = 0;
218 		cb->buf_idx = 0;
219 		list_move_tail(&cb->list, &cmpl_list->list);
220 		return -EIO;
221 	}
222 
223 	cl->state = MEI_FILE_DISCONNECTING;
224 	cl->status = 0;
225 	cb->buf_idx = 0;
226 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
227 	cl->timer_count = MEI_CONNECT_TIMEOUT;
228 
229 	return 0;
230 }
231 
232 
233 /**
234  * mei_cl_irq_read - processes client read related operation from the
235  *	interrupt thread context - request for flow control credits
236  *
237  * @cl: client
238  * @cb: callback block.
239  * @cmpl_list: complete list.
240  *
241  * Return: 0, OK; otherwise, error.
242  */
243 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
244 			   struct mei_cl_cb *cmpl_list)
245 {
246 	struct mei_device *dev = cl->dev;
247 	u32 msg_slots;
248 	int slots;
249 	int ret;
250 
251 	msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
252 	slots = mei_hbuf_empty_slots(dev);
253 
254 	if (slots < msg_slots)
255 		return -EMSGSIZE;
256 
257 	ret = mei_hbm_cl_flow_control_req(dev, cl);
258 	if (ret) {
259 		cl->status = ret;
260 		cb->buf_idx = 0;
261 		list_move_tail(&cb->list, &cmpl_list->list);
262 		return ret;
263 	}
264 
265 	list_move_tail(&cb->list, &cl->rd_pending);
266 
267 	return 0;
268 }
269 
270 
271 /**
272  * mei_cl_irq_connect - send connect request in irq_thread context
273  *
274  * @cl: client
275  * @cb: callback block.
276  * @cmpl_list: complete list.
277  *
278  * Return: 0, OK; otherwise, error.
279  */
280 static int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
281 			      struct mei_cl_cb *cmpl_list)
282 {
283 	struct mei_device *dev = cl->dev;
284 	u32 msg_slots;
285 	int slots;
286 	int ret;
287 
288 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
289 	slots = mei_hbuf_empty_slots(dev);
290 
291 	if (mei_cl_is_other_connecting(cl))
292 		return 0;
293 
294 	if (slots < msg_slots)
295 		return -EMSGSIZE;
296 
297 	cl->state = MEI_FILE_CONNECTING;
298 
299 	ret = mei_hbm_cl_connect_req(dev, cl);
300 	if (ret) {
301 		cl->status = ret;
302 		cb->buf_idx = 0;
303 		list_del_init(&cb->list);
304 		return ret;
305 	}
306 
307 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
308 	cl->timer_count = MEI_CONNECT_TIMEOUT;
309 	return 0;
310 }
311 
312 
313 /**
314  * mei_irq_read_handler - bottom half read routine after ISR to
315  * handle the read processing.
316  *
317  * @dev: the device structure
318  * @cmpl_list: An instance of our list structure
319  * @slots: slots to read.
320  *
321  * Return: 0 on success, <0 on failure.
322  */
323 int mei_irq_read_handler(struct mei_device *dev,
324 		struct mei_cl_cb *cmpl_list, s32 *slots)
325 {
326 	struct mei_msg_hdr *mei_hdr;
327 	struct mei_cl *cl;
328 	int ret;
329 
330 	if (!dev->rd_msg_hdr) {
331 		dev->rd_msg_hdr = mei_read_hdr(dev);
332 		(*slots)--;
333 		dev_dbg(dev->dev, "slots =%08x.\n", *slots);
334 	}
335 	mei_hdr = (struct mei_msg_hdr *) &dev->rd_msg_hdr;
336 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
337 
338 	if (mei_hdr->reserved || !dev->rd_msg_hdr) {
339 		dev_err(dev->dev, "corrupted message header 0x%08X\n",
340 				dev->rd_msg_hdr);
341 		ret = -EBADMSG;
342 		goto end;
343 	}
344 
345 	if (mei_slots2data(*slots) < mei_hdr->length) {
346 		dev_err(dev->dev, "less data available than length=%08x.\n",
347 				*slots);
348 		/* we can't read the message */
349 		ret = -ENODATA;
350 		goto end;
351 	}
352 
353 	/*  HBM message */
354 	if (mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0) {
355 		ret = mei_hbm_dispatch(dev, mei_hdr);
356 		if (ret) {
357 			dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
358 					ret);
359 			goto end;
360 		}
361 		goto reset_slots;
362 	}
363 
364 	/* find recipient cl */
365 	list_for_each_entry(cl, &dev->file_list, link) {
366 		if (mei_cl_hbm_equal(cl, mei_hdr)) {
367 			cl_dbg(dev, cl, "got a message\n");
368 			break;
369 		}
370 	}
371 
372 	/* if no recipient cl was found we assume corrupted header */
373 	if (&cl->link == &dev->file_list) {
374 		dev_err(dev->dev, "no destination client found 0x%08X\n",
375 				dev->rd_msg_hdr);
376 		ret = -EBADMSG;
377 		goto end;
378 	}
379 
380 	if (cl == &dev->iamthif_cl) {
381 		ret = mei_amthif_irq_read_msg(cl, mei_hdr, cmpl_list);
382 	} else {
383 		ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
384 	}
385 
386 
387 reset_slots:
388 	/* reset the number of slots and header */
389 	*slots = mei_count_full_read_slots(dev);
390 	dev->rd_msg_hdr = 0;
391 
392 	if (*slots == -EOVERFLOW) {
393 		/* overflow - reset */
394 		dev_err(dev->dev, "resetting due to slots overflow.\n");
395 		/* set the event since message has been read */
396 		ret = -ERANGE;
397 		goto end;
398 	}
399 end:
400 	return ret;
401 }
402 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
403 
404 
405 /**
406  * mei_irq_write_handler -  dispatch write requests
407  *  after irq received
408  *
409  * @dev: the device structure
410  * @cmpl_list: An instance of our list structure
411  *
412  * Return: 0 on success, <0 on failure.
413  */
414 int mei_irq_write_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list)
415 {
416 
417 	struct mei_cl *cl;
418 	struct mei_cl_cb *cb, *next;
419 	struct mei_cl_cb *list;
420 	s32 slots;
421 	int ret;
422 
423 
424 	if (!mei_hbuf_acquire(dev))
425 		return 0;
426 
427 	slots = mei_hbuf_empty_slots(dev);
428 	if (slots <= 0)
429 		return -EMSGSIZE;
430 
431 	/* complete all waiting for write CB */
432 	dev_dbg(dev->dev, "complete all waiting for write cb.\n");
433 
434 	list = &dev->write_waiting_list;
435 	list_for_each_entry_safe(cb, next, &list->list, list) {
436 		cl = cb->cl;
437 
438 		cl->status = 0;
439 		cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
440 		cl->writing_state = MEI_WRITE_COMPLETE;
441 		list_move_tail(&cb->list, &cmpl_list->list);
442 	}
443 
444 	if (dev->wd_state == MEI_WD_STOPPING) {
445 		dev->wd_state = MEI_WD_IDLE;
446 		wake_up(&dev->wait_stop_wd);
447 	}
448 
449 	if (mei_cl_is_connected(&dev->wd_cl)) {
450 		if (dev->wd_pending &&
451 		    mei_cl_flow_ctrl_creds(&dev->wd_cl) > 0) {
452 			ret = mei_wd_send(dev);
453 			if (ret)
454 				return ret;
455 			dev->wd_pending = false;
456 		}
457 	}
458 
459 	/* complete control write list CB */
460 	dev_dbg(dev->dev, "complete control write list cb.\n");
461 	list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list.list, list) {
462 		cl = cb->cl;
463 		switch (cb->fop_type) {
464 		case MEI_FOP_DISCONNECT:
465 			/* send disconnect message */
466 			ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
467 			if (ret)
468 				return ret;
469 
470 			break;
471 		case MEI_FOP_READ:
472 			/* send flow control message */
473 			ret = mei_cl_irq_read(cl, cb, cmpl_list);
474 			if (ret)
475 				return ret;
476 
477 			break;
478 		case MEI_FOP_CONNECT:
479 			/* connect message */
480 			ret = mei_cl_irq_connect(cl, cb, cmpl_list);
481 			if (ret)
482 				return ret;
483 
484 			break;
485 		case MEI_FOP_DISCONNECT_RSP:
486 			/* send disconnect resp */
487 			ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
488 			if (ret)
489 				return ret;
490 			break;
491 		default:
492 			BUG();
493 		}
494 
495 	}
496 	/* complete  write list CB */
497 	dev_dbg(dev->dev, "complete write list cb.\n");
498 	list_for_each_entry_safe(cb, next, &dev->write_list.list, list) {
499 		cl = cb->cl;
500 		if (cl == &dev->iamthif_cl)
501 			ret = mei_amthif_irq_write(cl, cb, cmpl_list);
502 		else
503 			ret = mei_cl_irq_write(cl, cb, cmpl_list);
504 		if (ret)
505 			return ret;
506 	}
507 	return 0;
508 }
509 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
510 
511 
512 
513 /**
514  * mei_timer - timer function.
515  *
516  * @work: pointer to the work_struct structure
517  *
518  */
519 void mei_timer(struct work_struct *work)
520 {
521 	unsigned long timeout;
522 	struct mei_cl *cl;
523 
524 	struct mei_device *dev = container_of(work,
525 					struct mei_device, timer_work.work);
526 
527 
528 	mutex_lock(&dev->device_lock);
529 
530 	/* Catch interrupt stalls during HBM init handshake */
531 	if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
532 	    dev->hbm_state != MEI_HBM_IDLE) {
533 
534 		if (dev->init_clients_timer) {
535 			if (--dev->init_clients_timer == 0) {
536 				dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
537 					dev->hbm_state);
538 				mei_reset(dev);
539 				goto out;
540 			}
541 		}
542 	}
543 
544 	if (dev->dev_state != MEI_DEV_ENABLED)
545 		goto out;
546 
547 	/*** connect/disconnect timeouts ***/
548 	list_for_each_entry(cl, &dev->file_list, link) {
549 		if (cl->timer_count) {
550 			if (--cl->timer_count == 0) {
551 				dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
552 				mei_reset(dev);
553 				goto out;
554 			}
555 		}
556 	}
557 
558 	if (!mei_cl_is_connected(&dev->iamthif_cl))
559 		goto out;
560 
561 	if (dev->iamthif_stall_timer) {
562 		if (--dev->iamthif_stall_timer == 0) {
563 			dev_err(dev->dev, "timer: amthif  hanged.\n");
564 			mei_reset(dev);
565 			dev->iamthif_canceled = false;
566 			dev->iamthif_state = MEI_IAMTHIF_IDLE;
567 			dev->iamthif_timer = 0;
568 
569 			mei_io_cb_free(dev->iamthif_current_cb);
570 			dev->iamthif_current_cb = NULL;
571 
572 			dev->iamthif_file_object = NULL;
573 			mei_amthif_run_next_cmd(dev);
574 		}
575 	}
576 
577 	if (dev->iamthif_timer) {
578 
579 		timeout = dev->iamthif_timer +
580 			mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
581 
582 		dev_dbg(dev->dev, "dev->iamthif_timer = %ld\n",
583 				dev->iamthif_timer);
584 		dev_dbg(dev->dev, "timeout = %ld\n", timeout);
585 		dev_dbg(dev->dev, "jiffies = %ld\n", jiffies);
586 		if (time_after(jiffies, timeout)) {
587 			/*
588 			 * User didn't read the AMTHI data on time (15sec)
589 			 * freeing AMTHI for other requests
590 			 */
591 
592 			dev_dbg(dev->dev, "freeing AMTHI for other requests\n");
593 
594 			mei_io_list_flush(&dev->amthif_rd_complete_list,
595 				&dev->iamthif_cl);
596 			mei_io_cb_free(dev->iamthif_current_cb);
597 			dev->iamthif_current_cb = NULL;
598 
599 			dev->iamthif_file_object->private_data = NULL;
600 			dev->iamthif_file_object = NULL;
601 			dev->iamthif_timer = 0;
602 			mei_amthif_run_next_cmd(dev);
603 
604 		}
605 	}
606 out:
607 	if (dev->dev_state != MEI_DEV_DISABLED)
608 		schedule_delayed_work(&dev->timer_work, 2 * HZ);
609 	mutex_unlock(&dev->device_lock);
610 }
611