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 list_move_tail(&cb->list, &cl->rd_pending);
228 static inline bool hdr_is_hbm(struct mei_msg_hdr *mei_hdr)
230 return mei_hdr->host_addr == 0 && mei_hdr->me_addr == 0;
233 static inline bool hdr_is_fixed(struct mei_msg_hdr *mei_hdr)
235 return mei_hdr->host_addr == 0 && mei_hdr->me_addr != 0;
238 static inline int hdr_is_valid(u32 msg_hdr)
240 struct mei_msg_hdr *mei_hdr;
242 mei_hdr = (struct mei_msg_hdr *)&msg_hdr;
243 if (!msg_hdr || mei_hdr->reserved)
250 * mei_irq_read_handler - bottom half read routine after ISR to
251 * handle the read processing.
253 * @dev: the device structure
254 * @cmpl_list: An instance of our list structure
255 * @slots: slots to read.
257 * Return: 0 on success, <0 on failure.
259 int mei_irq_read_handler(struct mei_device *dev,
260 struct list_head *cmpl_list, s32 *slots)
262 struct mei_msg_hdr *mei_hdr;
266 if (!dev->rd_msg_hdr) {
267 dev->rd_msg_hdr = mei_read_hdr(dev);
269 dev_dbg(dev->dev, "slots =%08x.\n", *slots);
271 ret = hdr_is_valid(dev->rd_msg_hdr);
273 dev_err(dev->dev, "corrupted message header 0x%08X\n",
279 mei_hdr = (struct mei_msg_hdr *)&dev->rd_msg_hdr;
280 dev_dbg(dev->dev, MEI_HDR_FMT, MEI_HDR_PRM(mei_hdr));
282 if (mei_slots2data(*slots) < mei_hdr->length) {
283 dev_err(dev->dev, "less data available than length=%08x.\n",
285 /* we can't read the message */
291 if (hdr_is_hbm(mei_hdr)) {
292 ret = mei_hbm_dispatch(dev, mei_hdr);
294 dev_dbg(dev->dev, "mei_hbm_dispatch failed ret = %d\n",
301 /* find recipient cl */
302 list_for_each_entry(cl, &dev->file_list, link) {
303 if (mei_cl_hbm_equal(cl, mei_hdr)) {
304 cl_dbg(dev, cl, "got a message\n");
309 /* if no recipient cl was found we assume corrupted header */
310 if (&cl->link == &dev->file_list) {
311 /* A message for not connected fixed address clients
312 * should be silently discarded
314 if (hdr_is_fixed(mei_hdr)) {
315 mei_irq_discard_msg(dev, mei_hdr);
319 dev_err(dev->dev, "no destination client found 0x%08X\n",
325 ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
329 /* reset the number of slots and header */
330 *slots = mei_count_full_read_slots(dev);
333 if (*slots == -EOVERFLOW) {
334 /* overflow - reset */
335 dev_err(dev->dev, "resetting due to slots overflow.\n");
336 /* set the event since message has been read */
343 EXPORT_SYMBOL_GPL(mei_irq_read_handler);
347 * mei_irq_write_handler - dispatch write requests
350 * @dev: the device structure
351 * @cmpl_list: An instance of our list structure
353 * Return: 0 on success, <0 on failure.
355 int mei_irq_write_handler(struct mei_device *dev, struct list_head *cmpl_list)
359 struct mei_cl_cb *cb, *next;
364 if (!mei_hbuf_acquire(dev))
367 slots = mei_hbuf_empty_slots(dev);
371 /* complete all waiting for write CB */
372 dev_dbg(dev->dev, "complete all waiting for write cb.\n");
374 list_for_each_entry_safe(cb, next, &dev->write_waiting_list, list) {
378 cl_dbg(dev, cl, "MEI WRITE COMPLETE\n");
379 cl->writing_state = MEI_WRITE_COMPLETE;
380 list_move_tail(&cb->list, cmpl_list);
383 /* complete control write list CB */
384 dev_dbg(dev->dev, "complete control write list cb.\n");
385 list_for_each_entry_safe(cb, next, &dev->ctrl_wr_list, list) {
387 switch (cb->fop_type) {
388 case MEI_FOP_DISCONNECT:
389 /* send disconnect message */
390 ret = mei_cl_irq_disconnect(cl, cb, cmpl_list);
396 /* send flow control message */
397 ret = mei_cl_irq_read(cl, cb, cmpl_list);
402 case MEI_FOP_CONNECT:
403 /* connect message */
404 ret = mei_cl_irq_connect(cl, cb, cmpl_list);
409 case MEI_FOP_DISCONNECT_RSP:
410 /* send disconnect resp */
411 ret = mei_cl_irq_disconnect_rsp(cl, cb, cmpl_list);
416 case MEI_FOP_NOTIFY_START:
417 case MEI_FOP_NOTIFY_STOP:
418 ret = mei_cl_irq_notify(cl, cb, cmpl_list);
427 /* complete write list CB */
428 dev_dbg(dev->dev, "complete write list cb.\n");
429 list_for_each_entry_safe(cb, next, &dev->write_list, list) {
431 ret = mei_cl_irq_write(cl, cb, cmpl_list);
437 EXPORT_SYMBOL_GPL(mei_irq_write_handler);
441 * mei_connect_timeout - connect/disconnect timeouts
445 static void mei_connect_timeout(struct mei_cl *cl)
447 struct mei_device *dev = cl->dev;
449 if (cl->state == MEI_FILE_CONNECTING) {
450 if (dev->hbm_f_dot_supported) {
451 cl->state = MEI_FILE_DISCONNECT_REQUIRED;
459 #define MEI_STALL_TIMER_FREQ (2 * HZ)
461 * mei_schedule_stall_timer - re-arm stall_timer work
463 * Schedule stall timer
465 * @dev: the device structure
467 void mei_schedule_stall_timer(struct mei_device *dev)
469 schedule_delayed_work(&dev->timer_work, MEI_STALL_TIMER_FREQ);
473 * mei_timer - timer function.
475 * @work: pointer to the work_struct structure
478 void mei_timer(struct work_struct *work)
481 struct mei_device *dev = container_of(work,
482 struct mei_device, timer_work.work);
483 bool reschedule_timer = false;
485 mutex_lock(&dev->device_lock);
487 /* Catch interrupt stalls during HBM init handshake */
488 if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
489 dev->hbm_state != MEI_HBM_IDLE) {
491 if (dev->init_clients_timer) {
492 if (--dev->init_clients_timer == 0) {
493 dev_err(dev->dev, "timer: init clients timeout hbm_state = %d.\n",
498 reschedule_timer = true;
502 if (dev->dev_state != MEI_DEV_ENABLED)
505 /*** connect/disconnect timeouts ***/
506 list_for_each_entry(cl, &dev->file_list, link) {
507 if (cl->timer_count) {
508 if (--cl->timer_count == 0) {
509 dev_err(dev->dev, "timer: connect/disconnect timeout.\n");
510 mei_connect_timeout(cl);
513 reschedule_timer = true;
518 if (dev->dev_state != MEI_DEV_DISABLED && reschedule_timer)
519 mei_schedule_stall_timer(dev);
521 mutex_unlock(&dev->device_lock);