xref: /openbmc/linux/drivers/misc/mei/interrupt.c (revision eb3fcf00)
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  mei_cl_host_addr(cl) == mei_hdr->host_addr &&
69 		mei_cl_me_id(cl) == 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 	mei_cl_set_disconnected(cl);
184 	mei_io_cb_free(cb);
185 	mei_me_cl_put(cl->me_cl);
186 	cl->me_cl = NULL;
187 
188 	return ret;
189 }
190 
191 /**
192  * mei_cl_irq_read - processes client read related operation from the
193  *	interrupt thread context - request for flow control credits
194  *
195  * @cl: client
196  * @cb: callback block.
197  * @cmpl_list: complete list.
198  *
199  * Return: 0, OK; otherwise, error.
200  */
201 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
202 			   struct mei_cl_cb *cmpl_list)
203 {
204 	struct mei_device *dev = cl->dev;
205 	u32 msg_slots;
206 	int slots;
207 	int ret;
208 
209 	msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
210 	slots = mei_hbuf_empty_slots(dev);
211 
212 	if (slots < msg_slots)
213 		return -EMSGSIZE;
214 
215 	ret = mei_hbm_cl_flow_control_req(dev, cl);
216 	if (ret) {
217 		cl->status = ret;
218 		cb->buf_idx = 0;
219 		list_move_tail(&cb->list, &cmpl_list->list);
220 		return ret;
221 	}
222 
223 	list_move_tail(&cb->list, &cl->rd_pending);
224 
225 	return 0;
226 }
227 
228 /**
229  * mei_irq_read_handler - bottom half read routine after ISR to
230  * handle the read processing.
231  *
232  * @dev: the device structure
233  * @cmpl_list: An instance of our list structure
234  * @slots: slots to read.
235  *
236  * Return: 0 on success, <0 on failure.
237  */
238 int mei_irq_read_handler(struct mei_device *dev,
239 		struct mei_cl_cb *cmpl_list, s32 *slots)
240 {
241 	struct mei_msg_hdr *mei_hdr;
242 	struct mei_cl *cl;
243 	int ret;
244 
245 	if (!dev->rd_msg_hdr) {
246 		dev->rd_msg_hdr = mei_read_hdr(dev);
247 		(*slots)--;
248 		dev_dbg(dev->dev, "slots =%08x.\n", *slots);
249 	}
250 	mei_hdr = (struct mei_msg_hdr *) &dev->rd_msg_hdr;
251 	dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
252 
253 	if (mei_hdr->reserved || !dev->rd_msg_hdr) {
254 		dev_err(dev->dev, "corrupted message header 0x%08X\n",
255 				dev->rd_msg_hdr);
256 		ret = -EBADMSG;
257 		goto end;
258 	}
259 
260 	if (mei_slots2data(*slots) < mei_hdr->length) {
261 		dev_err(dev->dev, "less data available than length=%08x.\n",
262 				*slots);
263 		/* we can't read the message */
264 		ret = -ENODATA;
265 		goto end;
266 	}
267 
268 	/*  HBM message */
269 	if (mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0) {
270 		ret = mei_hbm_dispatch(dev, mei_hdr);
271 		if (ret) {
272 			dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
273 					ret);
274 			goto end;
275 		}
276 		goto reset_slots;
277 	}
278 
279 	/* find recipient cl */
280 	list_for_each_entry(cl, &dev->file_list, link) {
281 		if (mei_cl_hbm_equal(cl, mei_hdr)) {
282 			cl_dbg(dev, cl, "got a message\n");
283 			break;
284 		}
285 	}
286 
287 	/* if no recipient cl was found we assume corrupted header */
288 	if (&cl->link == &dev->file_list) {
289 		dev_err(dev->dev, "no destination client found 0x%08X\n",
290 				dev->rd_msg_hdr);
291 		ret = -EBADMSG;
292 		goto end;
293 	}
294 
295 	if (cl == &dev->iamthif_cl) {
296 		ret = mei_amthif_irq_read_msg(cl, mei_hdr, cmpl_list);
297 	} else {
298 		ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
299 	}
300 
301 
302 reset_slots:
303 	/* reset the number of slots and header */
304 	*slots = mei_count_full_read_slots(dev);
305 	dev->rd_msg_hdr = 0;
306 
307 	if (*slots == -EOVERFLOW) {
308 		/* overflow - reset */
309 		dev_err(dev->dev, "resetting due to slots overflow.\n");
310 		/* set the event since message has been read */
311 		ret = -ERANGE;
312 		goto end;
313 	}
314 end:
315 	return ret;
316 }
317 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
318 
319 
320 /**
321  * mei_irq_write_handler -  dispatch write requests
322  *  after irq received
323  *
324  * @dev: the device structure
325  * @cmpl_list: An instance of our list structure
326  *
327  * Return: 0 on success, <0 on failure.
328  */
329 int mei_irq_write_handler(struct mei_device *dev, struct mei_cl_cb *cmpl_list)
330 {
331 
332 	struct mei_cl *cl;
333 	struct mei_cl_cb *cb, *next;
334 	struct mei_cl_cb *list;
335 	s32 slots;
336 	int ret;
337 
338 
339 	if (!mei_hbuf_acquire(dev))
340 		return 0;
341 
342 	slots = mei_hbuf_empty_slots(dev);
343 	if (slots <= 0)
344 		return -EMSGSIZE;
345 
346 	/* complete all waiting for write CB */
347 	dev_dbg(dev->dev, "complete all waiting for write cb.\n");
348 
349 	list = &dev->write_waiting_list;
350 	list_for_each_entry_safe(cb, next, &list->list, list) {
351 		cl = cb->cl;
352 
353 		cl->status = 0;
354 		cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
355 		cl->writing_state = MEI_WRITE_COMPLETE;
356 		list_move_tail(&cb->list, &cmpl_list->list);
357 	}
358 
359 	if (dev->wd_state == MEI_WD_STOPPING) {
360 		dev->wd_state = MEI_WD_IDLE;
361 		wake_up(&dev->wait_stop_wd);
362 	}
363 
364 	if (mei_cl_is_connected(&dev->wd_cl)) {
365 		if (dev->wd_pending &&
366 		    mei_cl_flow_ctrl_creds(&dev->wd_cl) > 0) {
367 			ret = mei_wd_send(dev);
368 			if (ret)
369 				return ret;
370 			dev->wd_pending = false;
371 		}
372 	}
373 
374 	/* complete control write list CB */
375 	dev_dbg(dev->dev, "complete control write list cb.\n");
376 	list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list.list, list) {
377 		cl = cb->cl;
378 		switch (cb->fop_type) {
379 		case MEI_FOP_DISCONNECT:
380 			/* send disconnect message */
381 			ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
382 			if (ret)
383 				return ret;
384 
385 			break;
386 		case MEI_FOP_READ:
387 			/* send flow control message */
388 			ret = mei_cl_irq_read(cl, cb, cmpl_list);
389 			if (ret)
390 				return ret;
391 
392 			break;
393 		case MEI_FOP_CONNECT:
394 			/* connect message */
395 			ret = mei_cl_irq_connect(cl, cb, cmpl_list);
396 			if (ret)
397 				return ret;
398 
399 			break;
400 		case MEI_FOP_DISCONNECT_RSP:
401 			/* send disconnect resp */
402 			ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
403 			if (ret)
404 				return ret;
405 			break;
406 
407 		case MEI_FOP_NOTIFY_START:
408 		case MEI_FOP_NOTIFY_STOP:
409 			ret = mei_cl_irq_notify(cl, cb, cmpl_list);
410 			if (ret)
411 				return ret;
412 			break;
413 		default:
414 			BUG();
415 		}
416 
417 	}
418 	/* complete  write list CB */
419 	dev_dbg(dev->dev, "complete write list cb.\n");
420 	list_for_each_entry_safe(cb, next, &dev->write_list.list, list) {
421 		cl = cb->cl;
422 		if (cl == &dev->iamthif_cl)
423 			ret = mei_amthif_irq_write(cl, cb, cmpl_list);
424 		else
425 			ret = mei_cl_irq_write(cl, cb, cmpl_list);
426 		if (ret)
427 			return ret;
428 	}
429 	return 0;
430 }
431 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
432 
433 
434 /**
435  * mei_connect_timeout  - connect/disconnect timeouts
436  *
437  * @cl: host client
438  */
439 static void mei_connect_timeout(struct mei_cl *cl)
440 {
441 	struct mei_device *dev = cl->dev;
442 
443 	if (cl->state == MEI_FILE_CONNECTING) {
444 		if (dev->hbm_f_dot_supported) {
445 			cl->state = MEI_FILE_DISCONNECT_REQUIRED;
446 			wake_up(&cl->wait);
447 			return;
448 		}
449 	}
450 	mei_reset(dev);
451 }
452 
453 /**
454  * mei_timer - timer function.
455  *
456  * @work: pointer to the work_struct structure
457  *
458  */
459 void mei_timer(struct work_struct *work)
460 {
461 	unsigned long timeout;
462 	struct mei_cl *cl;
463 
464 	struct mei_device *dev = container_of(work,
465 					struct mei_device, timer_work.work);
466 
467 
468 	mutex_lock(&dev->device_lock);
469 
470 	/* Catch interrupt stalls during HBM init handshake */
471 	if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
472 	    dev->hbm_state != MEI_HBM_IDLE) {
473 
474 		if (dev->init_clients_timer) {
475 			if (--dev->init_clients_timer == 0) {
476 				dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
477 					dev->hbm_state);
478 				mei_reset(dev);
479 				goto out;
480 			}
481 		}
482 	}
483 
484 	if (dev->dev_state != MEI_DEV_ENABLED)
485 		goto out;
486 
487 	/*** connect/disconnect timeouts ***/
488 	list_for_each_entry(cl, &dev->file_list, link) {
489 		if (cl->timer_count) {
490 			if (--cl->timer_count == 0) {
491 				dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
492 				mei_connect_timeout(cl);
493 				goto out;
494 			}
495 		}
496 	}
497 
498 	if (!mei_cl_is_connected(&dev->iamthif_cl))
499 		goto out;
500 
501 	if (dev->iamthif_stall_timer) {
502 		if (--dev->iamthif_stall_timer == 0) {
503 			dev_err(dev->dev, "timer: amthif  hanged.\n");
504 			mei_reset(dev);
505 			dev->iamthif_canceled = false;
506 			dev->iamthif_state = MEI_IAMTHIF_IDLE;
507 			dev->iamthif_timer = 0;
508 
509 			mei_io_cb_free(dev->iamthif_current_cb);
510 			dev->iamthif_current_cb = NULL;
511 
512 			dev->iamthif_file_object = NULL;
513 			mei_amthif_run_next_cmd(dev);
514 		}
515 	}
516 
517 	if (dev->iamthif_timer) {
518 
519 		timeout = dev->iamthif_timer +
520 			mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
521 
522 		dev_dbg(dev->dev, "dev->iamthif_timer = %ld\n",
523 				dev->iamthif_timer);
524 		dev_dbg(dev->dev, "timeout = %ld\n", timeout);
525 		dev_dbg(dev->dev, "jiffies = %ld\n", jiffies);
526 		if (time_after(jiffies, timeout)) {
527 			/*
528 			 * User didn't read the AMTHI data on time (15sec)
529 			 * freeing AMTHI for other requests
530 			 */
531 
532 			dev_dbg(dev->dev, "freeing AMTHI for other requests\n");
533 
534 			mei_io_list_flush(&dev->amthif_rd_complete_list,
535 				&dev->iamthif_cl);
536 			mei_io_cb_free(dev->iamthif_current_cb);
537 			dev->iamthif_current_cb = NULL;
538 
539 			dev->iamthif_file_object->private_data = NULL;
540 			dev->iamthif_file_object = NULL;
541 			dev->iamthif_timer = 0;
542 			mei_amthif_run_next_cmd(dev);
543 
544 		}
545 	}
546 out:
547 	if (dev->dev_state != MEI_DEV_DISABLED)
548 		schedule_delayed_work(&dev->timer_work, 2 * HZ);
549 	mutex_unlock(&dev->device_lock);
550 }
551