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 */
39void 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}
55EXPORT_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 */
65static 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 */
78static inline
79void 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 */
99int 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
152out:
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 */
168static 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 */
203static 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 */
243static 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 */
280static 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 */
323int 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
387reset_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	}
399end:
400	return ret;
401}
402EXPORT_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 */
414int 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}
509EXPORT_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 */
519void 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	}
606out:
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