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#include <linux/pm_runtime.h>
25
26#include <linux/mei.h>
27
28#include "mei_dev.h"
29#include "hbm.h"
30#include "client.h"
31
32
33/**
34 * mei_irq_compl_handler - dispatch complete handlers
35 *	for the completed callbacks
36 *
37 * @dev: mei device
38 * @compl_list: list of completed cbs
39 */
40void mei_irq_compl_handler(struct mei_device *dev, struct mei_cl_cb *compl_list)
41{
42	struct mei_cl_cb *cb, *next;
43	struct mei_cl *cl;
44
45	list_for_each_entry_safe(cb, next, &compl_list->list, list) {
46		cl = cb->cl;
47		list_del_init(&cb->list);
48
49		dev_dbg(dev->dev, "completing call back.\n");
50		if (cl == &dev->iamthif_cl)
51			mei_amthif_complete(dev, cb);
52		else
53			mei_cl_complete(cl, cb);
54	}
55}
56EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
57
58/**
59 * mei_cl_hbm_equal - check if hbm is addressed to the client
60 *
61 * @cl: host client
62 * @mei_hdr: header of mei client message
63 *
64 * Return: true if matches, false otherwise
65 */
66static inline int mei_cl_hbm_equal(struct mei_cl *cl,
67			struct mei_msg_hdr *mei_hdr)
68{
69	return  mei_cl_host_addr(cl) == mei_hdr->host_addr &&
70		mei_cl_me_id(cl) == mei_hdr->me_addr;
71}
72
73/**
74 * mei_irq_discard_msg  - discard received message
75 *
76 * @dev: mei device
77 * @hdr: message header
78 */
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	} else {
151		pm_runtime_mark_last_busy(dev->dev);
152		pm_request_autosuspend(dev->dev);
153	}
154
155out:
156	if (!buffer)
157		mei_irq_discard_msg(dev, mei_hdr);
158
159	return 0;
160}
161
162/**
163 * mei_cl_irq_disconnect_rsp - send disconnection response message
164 *
165 * @cl: client
166 * @cb: callback block.
167 * @cmpl_list: complete list.
168 *
169 * Return: 0, OK; otherwise, error.
170 */
171static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
172				     struct mei_cl_cb *cmpl_list)
173{
174	struct mei_device *dev = cl->dev;
175	u32 msg_slots;
176	int slots;
177	int ret;
178
179	slots = mei_hbuf_empty_slots(dev);
180	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_response));
181
182	if (slots < msg_slots)
183		return -EMSGSIZE;
184
185	ret = mei_hbm_cl_disconnect_rsp(dev, cl);
186	list_move_tail(&cb->list, &cmpl_list->list);
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 */
201static 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 */
238int 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
302reset_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	}
314end:
315	return ret;
316}
317EXPORT_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 */
329int 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}
431EXPORT_SYMBOL_GPL(mei_irq_write_handler);
432
433
434/**
435 * mei_connect_timeout  - connect/disconnect timeouts
436 *
437 * @cl: host client
438 */
439static 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 */
459void 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	}
546out:
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