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_stall_timer = 0;
54 dev->iamthif_open_count = 0;
58 * mei_amthif_host_init - mei initialization amthif client.
60 * @dev: the device structure
63 * Return: 0 on success, <0 on failure.
65 int mei_amthif_host_init(struct mei_device *dev, struct mei_me_client *me_cl)
67 struct mei_cl *cl = &dev->iamthif_cl;
70 dev->iamthif_state = MEI_IAMTHIF_IDLE;
74 ret = mei_cl_link(cl, MEI_IAMTHIF_HOST_CLIENT_ID);
76 dev_err(dev->dev, "amthif: failed cl_link %d\n", ret);
80 ret = mei_cl_connect(cl, me_cl, NULL);
82 dev->iamthif_state = MEI_IAMTHIF_IDLE;
88 * mei_amthif_read - read data from AMTHIF client
90 * @dev: the device structure
91 * @file: pointer to file object
92 * @ubuf: pointer to user data in user space
93 * @length: data length to read
94 * @offset: data read offset
96 * Locking: called under "dev->device_lock" lock
99 * returned data length on success,
100 * zero if no data to read,
101 * negative on failure.
103 int mei_amthif_read(struct mei_device *dev, struct file *file,
104 char __user *ubuf, size_t length, loff_t *offset)
106 struct mei_cl *cl = file->private_data;
107 struct mei_cl_cb *cb;
111 dev_dbg(dev->dev, "checking amthif data\n");
112 cb = mei_cl_read_cb(cl, file);
114 /* Check for if we can block or not*/
115 if (cb == NULL && file->f_flags & O_NONBLOCK)
119 dev_dbg(dev->dev, "waiting for amthif data\n");
121 /* unlock the Mutex */
122 mutex_unlock(&dev->device_lock);
124 wait_ret = wait_event_interruptible(cl->rx_wait,
125 !list_empty(&cl->rd_completed) ||
126 !mei_cl_is_connected(cl));
128 /* Locking again the Mutex */
129 mutex_lock(&dev->device_lock);
134 if (!mei_cl_is_connected(cl)) {
139 cb = mei_cl_read_cb(cl, file);
144 dev_dbg(dev->dev, "read operation failed %d\n", rets);
148 dev_dbg(dev->dev, "Got amthif data\n");
149 /* if the whole message will fit remove it from the list */
150 if (cb->buf_idx >= *offset && length >= (cb->buf_idx - *offset))
151 list_del_init(&cb->list);
152 else if (cb->buf_idx <= *offset) {
153 /* end of the message has been reached */
154 list_del_init(&cb->list);
158 /* else means that not full buffer will be read and do not
159 * remove message from deletion list
162 dev_dbg(dev->dev, "amthif cb->buf.size - %zd cb->buf_idx - %zd\n",
163 cb->buf.size, cb->buf_idx);
165 /* length is being truncated to PAGE_SIZE, however,
166 * the buf_idx may point beyond */
167 length = min_t(size_t, length, (cb->buf_idx - *offset));
169 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
170 dev_dbg(dev->dev, "failed to copy data to userland\n");
174 if ((*offset + length) < cb->buf_idx) {
180 dev_dbg(dev->dev, "free amthif cb memory.\n");
188 * mei_amthif_read_start - queue message for sending read credential
191 * @file: file pointer of message recipient
193 * Return: 0 on success, <0 on failure.
195 static int mei_amthif_read_start(struct mei_cl *cl, const struct file *file)
197 struct mei_device *dev = cl->dev;
198 struct mei_cl_cb *cb;
201 cb = mei_io_cb_init(cl, MEI_FOP_READ, file);
207 rets = mei_io_cb_alloc_buf(cb, mei_cl_mtu(cl));
211 list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
213 dev->iamthif_state = MEI_IAMTHIF_READING;
214 dev->iamthif_fp = cb->fp;
215 dev->iamthif_current_cb = cb;
224 * mei_amthif_send_cmd - send amthif command to the ME
226 * @cl: the host client
227 * @cb: mei call back struct
229 * Return: 0 on success, <0 on failure.
231 static int mei_amthif_send_cmd(struct mei_cl *cl, struct mei_cl_cb *cb)
233 struct mei_device *dev;
241 dev->iamthif_state = MEI_IAMTHIF_WRITING;
242 dev->iamthif_current_cb = cb;
243 dev->iamthif_fp = cb->fp;
244 dev->iamthif_canceled = false;
246 ret = mei_cl_write(cl, cb, false);
251 cb->status = mei_amthif_read_start(cl, cb->fp);
257 * mei_amthif_run_next_cmd - send next amt command from queue
259 * @dev: the device structure
261 * Return: 0 on success, <0 on failure.
263 int mei_amthif_run_next_cmd(struct mei_device *dev)
265 struct mei_cl *cl = &dev->iamthif_cl;
266 struct mei_cl_cb *cb;
268 dev->iamthif_canceled = false;
269 dev->iamthif_state = MEI_IAMTHIF_IDLE;
270 dev->iamthif_fp = NULL;
272 dev_dbg(dev->dev, "complete amthif cmd_list cb.\n");
274 cb = list_first_entry_or_null(&dev->amthif_cmd_list.list,
279 list_del_init(&cb->list);
280 return mei_amthif_send_cmd(cl, cb);
284 * mei_amthif_write - write amthif data to amthif client
287 * @cb: mei call back struct
289 * Return: 0 on success, <0 on failure.
291 int mei_amthif_write(struct mei_cl *cl, struct mei_cl_cb *cb)
294 struct mei_device *dev = cl->dev;
296 list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
299 * The previous request is still in processing, queue this one.
301 if (dev->iamthif_state > MEI_IAMTHIF_IDLE &&
302 dev->iamthif_state < MEI_IAMTHIF_READ_COMPLETE)
305 return mei_amthif_run_next_cmd(dev);
309 * mei_amthif_poll - the amthif poll function
311 * @dev: the device structure
312 * @file: pointer to file structure
313 * @wait: pointer to poll_table structure
317 * Locking: called under "dev->device_lock" lock
320 unsigned int mei_amthif_poll(struct mei_device *dev,
321 struct file *file, poll_table *wait)
323 unsigned int mask = 0;
325 poll_wait(file, &dev->iamthif_cl.rx_wait, wait);
327 if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
328 dev->iamthif_fp == file) {
330 mask |= POLLIN | POLLRDNORM;
331 mei_amthif_run_next_cmd(dev);
340 * mei_amthif_irq_write - write iamthif command in irq thread context.
342 * @cl: private data of the file object.
343 * @cb: callback block.
344 * @cmpl_list: complete list.
346 * Return: 0, OK; otherwise, error.
348 int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
349 struct mei_cl_cb *cmpl_list)
353 ret = mei_cl_irq_write(cl, cb, cmpl_list);
358 cb->status = mei_amthif_read_start(cl, cb->fp);
364 * mei_amthif_irq_read_msg - read routine after ISR to
365 * handle the read amthif message
368 * @mei_hdr: header of amthif message
369 * @cmpl_list: completed callbacks list
371 * Return: -ENODEV if cb is NULL 0 otherwise; error message is in cb->status
373 int mei_amthif_irq_read_msg(struct mei_cl *cl,
374 struct mei_msg_hdr *mei_hdr,
375 struct mei_cl_cb *cmpl_list)
377 struct mei_device *dev;
382 if (dev->iamthif_state != MEI_IAMTHIF_READING)
385 ret = mei_cl_irq_read_msg(cl, mei_hdr, cmpl_list);
389 if (!mei_hdr->msg_complete)
392 dev_dbg(dev->dev, "completed amthif read.\n ");
393 dev->iamthif_current_cb = NULL;
394 dev->iamthif_stall_timer = 0;
400 * mei_amthif_complete - complete amthif callback.
403 * @cb: callback block.
405 void mei_amthif_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
407 struct mei_device *dev = cl->dev;
409 if (cb->fop_type == MEI_FOP_WRITE) {
411 dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
416 * in case of error enqueue the write cb to complete read list
417 * so it can be propagated to the reader
419 list_add_tail(&cb->list, &cl->rd_completed);
420 wake_up_interruptible(&cl->rx_wait);
424 if (!dev->iamthif_canceled) {
425 dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
426 dev->iamthif_stall_timer = 0;
427 list_add_tail(&cb->list, &cl->rd_completed);
428 dev_dbg(dev->dev, "amthif read completed\n");
430 mei_amthif_run_next_cmd(dev);
433 dev_dbg(dev->dev, "completing amthif call back.\n");
434 wake_up_interruptible(&cl->rx_wait);
438 * mei_clear_list - removes all callbacks associated with file
441 * @dev: device structure.
442 * @file: file structure
443 * @mei_cb_list: callbacks list
445 * mei_clear_list is called to clear resources associated with file
446 * when application calls close function or Ctrl-C was pressed
448 * Return: true if callback removed from the list, false otherwise
450 static bool mei_clear_list(struct mei_device *dev,
451 const struct file *file, struct list_head *mei_cb_list)
453 struct mei_cl *cl = &dev->iamthif_cl;
454 struct mei_cl_cb *cb, *next;
455 bool removed = false;
457 /* list all list member */
458 list_for_each_entry_safe(cb, next, mei_cb_list, list) {
459 /* check if list member associated with a file */
460 if (file == cb->fp) {
461 /* check if cb equal to current iamthif cb */
462 if (dev->iamthif_current_cb == cb) {
463 dev->iamthif_current_cb = NULL;
464 /* send flow control to iamthif client */
465 mei_hbm_cl_flow_control_req(dev, cl);
467 /* free all allocated buffers */
476 * mei_clear_lists - removes all callbacks associated with file
478 * @dev: device structure
479 * @file: file structure
481 * mei_clear_lists is called to clear resources associated with file
482 * when application calls close function or Ctrl-C was pressed
484 * Return: true if callback removed from the list, false otherwise
486 static bool mei_clear_lists(struct mei_device *dev, const struct file *file)
488 bool removed = false;
489 struct mei_cl *cl = &dev->iamthif_cl;
491 /* remove callbacks associated with a file */
492 mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
493 if (mei_clear_list(dev, file, &cl->rd_completed))
496 mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
498 if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
501 if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
504 if (mei_clear_list(dev, file, &dev->write_list.list))
507 /* check if iamthif_current_cb not NULL */
508 if (dev->iamthif_current_cb && !removed) {
509 /* check file and iamthif current cb association */
510 if (dev->iamthif_current_cb->fp == file) {
512 mei_io_cb_free(dev->iamthif_current_cb);
513 dev->iamthif_current_cb = NULL;
521 * mei_amthif_release - the release function
523 * @dev: device structure
524 * @file: pointer to file structure
526 * Return: 0 on success, <0 on error
528 int mei_amthif_release(struct mei_device *dev, struct file *file)
530 if (dev->iamthif_open_count > 0)
531 dev->iamthif_open_count--;
533 if (dev->iamthif_fp == file &&
534 dev->iamthif_state != MEI_IAMTHIF_IDLE) {
536 dev_dbg(dev->dev, "amthif canceled iamthif state %d\n",
538 dev->iamthif_canceled = true;
539 if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
540 dev_dbg(dev->dev, "run next amthif iamthif cb\n");
541 mei_amthif_run_next_cmd(dev);
545 if (mei_clear_lists(dev, file))
546 dev->iamthif_state = MEI_IAMTHIF_IDLE;