3 * Intel Management Engine Interface (Intel MEI) Linux driver
4 * Copyright (c) 2003-2012, Intel Corporation.
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.
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
18 #include <linux/export.h>
19 #include <linux/kthread.h>
20 #include <linux/interrupt.h>
22 #include <linux/jiffies.h>
23 #include <linux/slab.h>
24 #include <linux/pm_runtime.h>
26 #include <linux/mei.h>
34 * mei_irq_compl_handler - dispatch complete handlers
35 * for the completed callbacks
38 * @cmpl_list: list of completed cbs
40 void mei_irq_compl_handler(struct mei_device *dev, struct list_head *cmpl_list)
42 struct mei_cl_cb *cb, *next;
45 list_for_each_entry_safe(cb, next, cmpl_list, list) {
47 list_del_init(&cb->list);
49 dev_dbg(dev->dev, "completing call back.\n");
50 mei_cl_complete(cl, cb);
53 EXPORT_SYMBOL_GPL(mei_irq_compl_handler);
56 * mei_cl_hbm_equal - check if hbm is addressed to the client
59 * @mei_hdr: header of mei client message
61 * Return: true if matches, false otherwise
63 static inline int mei_cl_hbm_equal(struct mei_cl *cl,
64 struct mei_msg_hdr *mei_hdr)
66 return mei_cl_host_addr(cl) == mei_hdr->host_addr &&
67 mei_cl_me_id(cl) == mei_hdr->me_addr;
71 * mei_irq_discard_msg - discard received message
74 * @hdr: message header
76 static void mei_irq_discard_msg(struct mei_device *dev, struct mei_msg_hdr *hdr)
79 * no need to check for size as it is guarantied
80 * that length fits into rd_msg_buf
82 mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
83 dev_dbg(dev->dev, "discarding message " MEI_HDR_FMT "\n",
88 * mei_cl_irq_read_msg - process client message
91 * @mei_hdr: header of mei client message
92 * @cmpl_list: completion list
96 static int mei_cl_irq_read_msg(struct mei_cl *cl,
97 struct mei_msg_hdr *mei_hdr,
98 struct list_head *cmpl_list)
100 struct mei_device *dev = cl->dev;
101 struct mei_cl_cb *cb;
104 cb = list_first_entry_or_null(&cl->rd_pending, struct mei_cl_cb, list);
106 if (!mei_cl_is_fixed_address(cl)) {
107 cl_err(dev, cl, "pending read cb not found\n");
110 cb = mei_cl_alloc_cb(cl, mei_cl_mtu(cl), MEI_FOP_READ, cl->fp);
113 list_add_tail(&cb->list, &cl->rd_pending);
116 if (!mei_cl_is_connected(cl)) {
117 cl_dbg(dev, cl, "not connected\n");
118 cb->status = -ENODEV;
122 buf_sz = mei_hdr->length + cb->buf_idx;
123 /* catch for integer overflow */
124 if (buf_sz < cb->buf_idx) {
125 cl_err(dev, cl, "message is too big len %d idx %zu\n",
126 mei_hdr->length, cb->buf_idx);
127 cb->status = -EMSGSIZE;
131 if (cb->buf.size < buf_sz) {
132 cl_dbg(dev, cl, "message overflow. size %zu len %d idx %zu\n",
133 cb->buf.size, mei_hdr->length, cb->buf_idx);
134 cb->status = -EMSGSIZE;
138 mei_read_slots(dev, cb->buf.data + cb->buf_idx, mei_hdr->length);
140 cb->buf_idx += mei_hdr->length;
142 if (mei_hdr->msg_complete) {
143 cl_dbg(dev, cl, "completed read length = %zu\n", cb->buf_idx);
144 list_move_tail(&cb->list, cmpl_list);
146 pm_runtime_mark_last_busy(dev->dev);
147 pm_request_autosuspend(dev->dev);
154 list_move_tail(&cb->list, cmpl_list);
155 mei_irq_discard_msg(dev, mei_hdr);
160 * mei_cl_irq_disconnect_rsp - send disconnection response message
163 * @cb: callback block.
164 * @cmpl_list: complete list.
166 * Return: 0, OK; otherwise, error.
168 static int mei_cl_irq_disconnect_rsp(struct mei_cl *cl, struct mei_cl_cb *cb,
169 struct list_head *cmpl_list)
171 struct mei_device *dev = cl->dev;
176 slots = mei_hbuf_empty_slots(dev);
177 msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_response));
179 if (slots < msg_slots)
182 ret = mei_hbm_cl_disconnect_rsp(dev, cl);
183 list_move_tail(&cb->list, cmpl_list);
189 * mei_cl_irq_read - processes client read related operation from the
190 * interrupt thread context - request for flow control credits
193 * @cb: callback block.
194 * @cmpl_list: complete list.
196 * Return: 0, OK; otherwise, error.
198 static int mei_cl_irq_read(struct mei_cl *cl, struct mei_cl_cb *cb,
199 struct list_head *cmpl_list)
201 struct mei_device *dev = cl->dev;
206 if (!list_empty(&cl->rd_pending))
209 msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
210 slots = mei_hbuf_empty_slots(dev);
212 if (slots < msg_slots)
215 ret = mei_hbm_cl_flow_control_req(dev, cl);
219 list_move_tail(&cb->list, cmpl_list);
223 pm_runtime_mark_last_busy(dev->dev);
224 pm_request_autosuspend(dev->dev);
226 list_move_tail(&cb->list, &cl->rd_pending);
231 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
233 return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
236 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
238 return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
241 static inline int hdr_is_valid(u32 msg_hdr)
243 struct mei_msg_hdr *mei_hdr;
245 mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
246 if (!msg_hdr || mei_hdr->reserved)
253 * mei_irq_read_handler - bottom half read routine after ISR to
254 * handle the read processing.
256 * @dev: the device structure
257 * @cmpl_list: An instance of our list structure
258 * @slots: slots to read.
260 * Return: 0 on success, <0 on failure.
262 int mei_irq_read_handler(struct mei_device *dev,
263 struct list_head *cmpl_list, s32 *slots)
265 struct mei_msg_hdr *mei_hdr;
269 if (!dev->rd_msg_hdr) {
270 dev->rd_msg_hdr = mei_read_hdr(dev);
272 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
274 ret = hdr_is_valid(dev->rd_msg_hdr);
276 dev_err(dev->dev, "corrupted message header 0x%08X\n",
282 mei_hdr = (struct mei_msg_hdr *)&dev->rd_msg_hdr;
283 dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
285 if (mei_slots2data(*slots) < mei_hdr->length) {
286 dev_err(dev->dev, "less data available than length=%08x.\n",
288 /* we can't read the message */
294 if (hdr_is_hbm(mei_hdr)) {
295 ret = mei_hbm_dispatch(dev, mei_hdr);
297 dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
304 /* find recipient cl */
305 list_for_each_entry(cl, &dev->file_list, link) {
306 if (mei_cl_hbm_equal(cl, mei_hdr)) {
307 cl_dbg(dev, cl, "got a message\n");
312 /* if no recipient cl was found we assume corrupted header */
313 if (&cl->link == &dev->file_list) {
314 /* A message for not connected fixed address clients
315 * should be silently discarded
317 if (hdr_is_fixed(mei_hdr)) {
318 mei_irq_discard_msg(dev, mei_hdr);
322 dev_err(dev->dev, "no destination client found 0x%08X\n",
328 ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
332 /* reset the number of slots and header */
333 *slots = mei_count_full_read_slots(dev);
336 if (*slots == -EOVERFLOW) {
337 /* overflow - reset */
338 dev_err(dev->dev, "resetting due to slots overflow.\n");
339 /* set the event since message has been read */
346 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
350 * mei_irq_write_handler - dispatch write requests
353 * @dev: the device structure
354 * @cmpl_list: An instance of our list structure
356 * Return: 0 on success, <0 on failure.
358 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
362 struct mei_cl_cb *cb, *next;
367 if (!mei_hbuf_acquire(dev))
370 slots = mei_hbuf_empty_slots(dev);
374 /* complete all waiting for write CB */
375 dev_dbg(dev->dev, "complete all waiting for write cb.\n");
377 list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
381 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
382 cl->writing_state = MEI_WRITE_COMPLETE;
383 list_move_tail(&cb->list, cmpl_list);
386 /* complete control write list CB */
387 dev_dbg(dev->dev, "complete control write list cb.\n");
388 list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
390 switch (cb->fop_type) {
391 case MEI_FOP_DISCONNECT:
392 /* send disconnect message */
393 ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
399 /* send flow control message */
400 ret = mei_cl_irq_read(cl, cb, cmpl_list);
405 case MEI_FOP_CONNECT:
406 /* connect message */
407 ret = mei_cl_irq_connect(cl, cb, cmpl_list);
412 case MEI_FOP_DISCONNECT_RSP:
413 /* send disconnect resp */
414 ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
419 case MEI_FOP_NOTIFY_START:
420 case MEI_FOP_NOTIFY_STOP:
421 ret = mei_cl_irq_notify(cl, cb, cmpl_list);
430 /* complete write list CB */
431 dev_dbg(dev->dev, "complete write list cb.\n");
432 list_for_each_entry_safe(cb, next, &dev->write_list, list) {
434 ret = mei_cl_irq_write(cl, cb, cmpl_list);
440 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
444 * mei_connect_timeout - connect/disconnect timeouts
448 static void mei_connect_timeout(struct mei_cl *cl)
450 struct mei_device *dev = cl->dev;
452 if (cl->state == MEI_FILE_CONNECTING) {
453 if (dev->hbm_f_dot_supported) {
454 cl->state = MEI_FILE_DISCONNECT_REQUIRED;
462 #define MEI_STALL_TIMER_FREQ (2 * HZ)
464 * mei_schedule_stall_timer - re-arm stall_timer work
466 * Schedule stall timer
468 * @dev: the device structure
470 void mei_schedule_stall_timer(struct mei_device *dev)
472 schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
476 * mei_timer - timer function.
478 * @work: pointer to the work_struct structure
481 void mei_timer(struct work_struct *work)
484 struct mei_device *dev = container_of(work,
485 struct mei_device, timer_work.work);
486 bool reschedule_timer = false;
488 mutex_lock(&dev->device_lock);
490 /* Catch interrupt stalls during HBM init handshake */
491 if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
492 dev->hbm_state != MEI_HBM_IDLE) {
494 if (dev->init_clients_timer) {
495 if (--dev->init_clients_timer == 0) {
496 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
501 reschedule_timer = true;
505 if (dev->dev_state != MEI_DEV_ENABLED)
508 /*** connect/disconnect timeouts ***/
509 list_for_each_entry(cl, &dev->file_list, link) {
510 if (cl->timer_count) {
511 if (--cl->timer_count == 0) {
512 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
513 mei_connect_timeout(cl);
516 reschedule_timer = true;
521 if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
522 mei_schedule_stall_timer(dev);
524 mutex_unlock(&dev->device_lock);