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
17 #include <linux/kernel.h>
19 #include <linux/errno.h>
20 #include <linux/types.h>
21 #include <linux/fcntl.h>
22 #include <linux/ioctl.h>
23 #include <linux/cdev.h>
24 #include <linux/list.h>
25 #include <linux/delay.h>
26 #include <linux/sched.h>
27 #include <linux/uuid.h>
28 #include <linux/jiffies.h>
29 #include <linux/uaccess.h>
30 #include <linux/slab.h>
32 #include <linux/mei.h>
38 const uuid_le mei_amthif_guid = UUID_LE(0x12f80028, 0xb4b7, 0x4b2d,
39 0xac, 0xa8, 0x46, 0xe0,
40 0xff, 0x65, 0x81, 0x4c);
43 * mei_amthif_reset_params - initializes mei device iamthif
45 * @dev: the device structure
47 void mei_amthif_reset_params(struct mei_device *dev)
49 /* reset iamthif parameters. */
50 dev->iamthif_current_cb = NULL;
51 dev->iamthif_canceled = false;
52 dev->iamthif_state = MEI_IAMTHIF_IDLE;
53 dev->iamthif_timer = 0;
54 dev->iamthif_stall_timer = 0;
55 dev->iamthif_open_count = 0;
59 * mei_amthif_host_init - mei initialization amthif client.
61 * @dev: the device structure
64 * Return: 0 on success, <0 on failure.
66 int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl)
68 struct mei_cl *cl = &dev->iamthif_cl;
71 dev->iamthif_state = MEI_IAMTHIF_IDLE;
75 ret = mei_cl_link(cl, MEI_IAMTHIF_HOST_CLIENT_ID);
77 dev_err(dev->dev, "amthif: failed cl_link %d\n", ret);
81 ret = mei_cl_connect(cl, me_cl, NULL);
83 dev->iamthif_state = MEI_IAMTHIF_IDLE;
89 * mei_amthif_find_read_list_entry - finds a amthilist entry for current file
91 * @dev: the device structure
92 * @file: pointer to file object
94 * Return: returned a list entry on success, NULL on failure.
96 struct mei_cl_cb *mei_amthif_find_read_list_entry(struct mei_device *dev,
101 list_for_each_entry(cb, &dev->amthif_rd_complete_list.list, list)
102 if (cb->file_object == file)
109 * mei_amthif_read - read data from AMTHIF client
111 * @dev: the device structure
112 * @file: pointer to file object
113 * @ubuf: pointer to user data in user space
114 * @length: data length to read
115 * @offset: data read offset
117 * Locking: called under "dev->device_lock" lock
120 * returned data length on success,
121 * zero if no data to read,
122 * negative on failure.
124 int mei_amthif_read(struct mei_device *dev, struct file *file,
125 char __user *ubuf, size_t length, loff_t *offset)
127 struct mei_cl *cl = file->private_data;
128 struct mei_cl_cb *cb;
129 unsigned long timeout;
133 /* Only possible if we are in timeout */
135 dev_err(dev->dev, "bad file ext.\n");
139 dev_dbg(dev->dev, "checking amthif data\n");
140 cb = mei_amthif_find_read_list_entry(dev, file);
142 /* Check for if we can block or not*/
143 if (cb == NULL && file->f_flags & O_NONBLOCK)
147 dev_dbg(dev->dev, "waiting for amthif data\n");
149 /* unlock the Mutex */
150 mutex_unlock(&dev->device_lock);
152 wait_ret = wait_event_interruptible(dev->iamthif_cl.wait,
153 (cb = mei_amthif_find_read_list_entry(dev, file)));
155 /* Locking again the Mutex */
156 mutex_lock(&dev->device_lock);
161 dev_dbg(dev->dev, "woke up from sleep\n");
166 dev_dbg(dev->dev, "read operation failed %d\n", rets);
170 dev_dbg(dev->dev, "Got amthif data\n");
171 dev->iamthif_timer = 0;
173 timeout = cb->read_time +
174 mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
175 dev_dbg(dev->dev, "amthif timeout = %lud\n",
178 if (time_after(jiffies, timeout)) {
179 dev_dbg(dev->dev, "amthif Time out\n");
180 /* 15 sec for the message has expired */
181 list_del_init(&cb->list);
185 /* if the whole message will fit remove it from the list */
186 if (cb->buf_idx >= *offset && length >= (cb->buf_idx - *offset))
187 list_del_init(&cb->list);
188 else if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
189 /* end of the message has been reached */
190 list_del_init(&cb->list);
194 /* else means that not full buffer will be read and do not
195 * remove message from deletion list
198 dev_dbg(dev->dev, "amthif cb->buf size - %d\n",
200 dev_dbg(dev->dev, "amthif cb->buf_idx - %lu\n", cb->buf_idx);
202 /* length is being truncated to PAGE_SIZE, however,
203 * the buf_idx may point beyond */
204 length = min_t(size_t, length, (cb->buf_idx - *offset));
206 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
207 dev_dbg(dev->dev, "failed to copy data to userland\n");
211 if ((*offset + length) < cb->buf_idx) {
217 dev_dbg(dev->dev, "free amthif cb memory.\n");
225 * mei_amthif_read_start - queue message for sending read credential
228 * @file: file pointer of message recipient
230 * Return: 0 on success, <0 on failure.
232 static int mei_amthif_read_start(struct mei_cl *cl, struct file *file)
234 struct mei_device *dev = cl->dev;
235 struct mei_cl_cb *cb;
238 cb = mei_io_cb_init(cl, MEI_FOP_READ, file);
244 rets = mei_io_cb_alloc_buf(cb, mei_cl_mtu(cl));
248 list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
250 dev->iamthif_state = MEI_IAMTHIF_READING;
251 dev->iamthif_file_object = cb->file_object;
252 dev->iamthif_current_cb = cb;
261 * mei_amthif_send_cmd - send amthif command to the ME
263 * @cl: the host client
264 * @cb: mei call back struct
266 * Return: 0 on success, <0 on failure.
268 static int mei_amthif_send_cmd(struct mei_cl *cl, struct mei_cl_cb *cb)
270 struct mei_device *dev;
278 dev->iamthif_state = MEI_IAMTHIF_WRITING;
279 dev->iamthif_current_cb = cb;
280 dev->iamthif_file_object = cb->file_object;
281 dev->iamthif_canceled = false;
283 ret = mei_cl_write(cl, cb, false);
288 cb->status = mei_amthif_read_start(cl, cb->file_object);
294 * mei_amthif_run_next_cmd - send next amt command from queue
296 * @dev: the device structure
298 * Return: 0 on success, <0 on failure.
300 int mei_amthif_run_next_cmd(struct mei_device *dev)
302 struct mei_cl *cl = &dev->iamthif_cl;
303 struct mei_cl_cb *cb;
305 dev->iamthif_canceled = false;
306 dev->iamthif_state = MEI_IAMTHIF_IDLE;
307 dev->iamthif_timer = 0;
308 dev->iamthif_file_object = NULL;
310 dev_dbg(dev->dev, "complete amthif cmd_list cb.\n");
312 cb = list_first_entry_or_null(&dev->amthif_cmd_list.list,
317 list_del_init(&cb->list);
318 return mei_amthif_send_cmd(cl, cb);
322 * mei_amthif_write - write amthif data to amthif client
325 * @cb: mei call back struct
327 * Return: 0 on success, <0 on failure.
329 int mei_amthif_write(struct mei_cl *cl, struct mei_cl_cb *cb)
332 struct mei_device *dev;
334 if (WARN_ON(!cl || !cl->dev))
342 list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
343 return mei_amthif_run_next_cmd(dev);
347 * mei_amthif_poll - the amthif poll function
349 * @dev: the device structure
350 * @file: pointer to file structure
351 * @wait: pointer to poll_table structure
355 * Locking: called under "dev->device_lock" lock
358 unsigned int mei_amthif_poll(struct mei_device *dev,
359 struct file *file, poll_table *wait)
361 unsigned int mask = 0;
363 poll_wait(file, &dev->iamthif_cl.wait, wait);
365 if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
366 dev->iamthif_file_object == file) {
368 mask |= POLLIN | POLLRDNORM;
369 mei_amthif_run_next_cmd(dev);
378 * mei_amthif_irq_write - write iamthif command in irq thread context.
380 * @cl: private data of the file object.
381 * @cb: callback block.
382 * @cmpl_list: complete list.
384 * Return: 0, OK; otherwise, error.
386 int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
387 struct mei_cl_cb *cmpl_list)
391 ret = mei_cl_irq_write(cl, cb, cmpl_list);
396 cb->status = mei_amthif_read_start(cl, cb->file_object);
402 * mei_amthif_irq_read_msg - read routine after ISR to
403 * handle the read amthif message
406 * @mei_hdr: header of amthif message
407 * @cmpl_list: completed callbacks list
409 * Return: -ENODEV if cb is NULL 0 otherwise; error message is in cb->status
411 int mei_amthif_irq_read_msg(struct mei_cl *cl,
412 struct mei_msg_hdr *mei_hdr,
413 struct mei_cl_cb *cmpl_list)
415 struct mei_device *dev;
420 if (dev->iamthif_state != MEI_IAMTHIF_READING)
423 ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
427 if (!mei_hdr->msg_complete)
430 dev_dbg(dev->dev, "completed amthif read.\n ");
431 dev->iamthif_current_cb = NULL;
432 dev->iamthif_stall_timer = 0;
438 * mei_amthif_complete - complete amthif callback.
440 * @dev: the device structure.
441 * @cb: callback block.
443 void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb)
446 if (cb->fop_type == MEI_FOP_WRITE) {
448 dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
453 * in case of error enqueue the write cb to complete read list
454 * so it can be propagated to the reader
456 list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
457 wake_up_interruptible(&dev->iamthif_cl.wait);
461 if (dev->iamthif_canceled != 1) {
462 dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
463 dev->iamthif_stall_timer = 0;
464 list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
465 dev_dbg(dev->dev, "amthif read completed\n");
466 dev->iamthif_timer = jiffies;
467 dev_dbg(dev->dev, "dev->iamthif_timer = %ld\n",
470 mei_amthif_run_next_cmd(dev);
473 dev_dbg(dev->dev, "completing amthif call back.\n");
474 wake_up_interruptible(&dev->iamthif_cl.wait);
478 * mei_clear_list - removes all callbacks associated with file
481 * @dev: device structure.
482 * @file: file structure
483 * @mei_cb_list: callbacks list
485 * mei_clear_list is called to clear resources associated with file
486 * when application calls close function or Ctrl-C was pressed
488 * Return: true if callback removed from the list, false otherwise
490 static bool mei_clear_list(struct mei_device *dev,
491 const struct file *file, struct list_head *mei_cb_list)
493 struct mei_cl *cl = &dev->iamthif_cl;
494 struct mei_cl_cb *cb, *next;
495 bool removed = false;
497 /* list all list member */
498 list_for_each_entry_safe(cb, next, mei_cb_list, list) {
499 /* check if list member associated with a file */
500 if (file == cb->file_object) {
501 /* check if cb equal to current iamthif cb */
502 if (dev->iamthif_current_cb == cb) {
503 dev->iamthif_current_cb = NULL;
504 /* send flow control to iamthif client */
505 mei_hbm_cl_flow_control_req(dev, cl);
507 /* free all allocated buffers */
516 * mei_clear_lists - removes all callbacks associated with file
518 * @dev: device structure
519 * @file: file structure
521 * mei_clear_lists is called to clear resources associated with file
522 * when application calls close function or Ctrl-C was pressed
524 * Return: true if callback removed from the list, false otherwise
526 static bool mei_clear_lists(struct mei_device *dev, struct file *file)
528 bool removed = false;
530 /* remove callbacks associated with a file */
531 mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
532 if (mei_clear_list(dev, file, &dev->amthif_rd_complete_list.list))
535 mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
537 if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
540 if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
543 if (mei_clear_list(dev, file, &dev->write_list.list))
546 /* check if iamthif_current_cb not NULL */
547 if (dev->iamthif_current_cb && !removed) {
548 /* check file and iamthif current cb association */
549 if (dev->iamthif_current_cb->file_object == file) {
551 mei_io_cb_free(dev->iamthif_current_cb);
552 dev->iamthif_current_cb = NULL;
560 * mei_amthif_release - the release function
562 * @dev: device structure
563 * @file: pointer to file structure
565 * Return: 0 on success, <0 on error
567 int mei_amthif_release(struct mei_device *dev, struct file *file)
569 if (dev->iamthif_open_count > 0)
570 dev->iamthif_open_count--;
572 if (dev->iamthif_file_object == file &&
573 dev->iamthif_state != MEI_IAMTHIF_IDLE) {
575 dev_dbg(dev->dev, "amthif canceled iamthif state %d\n",
577 dev->iamthif_canceled = true;
578 if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
579 dev_dbg(dev->dev, "run next amthif iamthif cb\n");
580 mei_amthif_run_next_cmd(dev);
584 if (mei_clear_lists(dev, file))
585 dev->iamthif_state = MEI_IAMTHIF_IDLE;