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 #include <linux/module.h> 17 #include <linux/moduleparam.h> 18 #include <linux/kernel.h> 19 #include <linux/device.h> 20 #include <linux/slab.h> 21 #include <linux/fs.h> 22 #include <linux/errno.h> 23 #include <linux/types.h> 24 #include <linux/fcntl.h> 25 #include <linux/poll.h> 26 #include <linux/init.h> 27 #include <linux/ioctl.h> 28 #include <linux/cdev.h> 29 #include <linux/sched/signal.h> 30 #include <linux/uuid.h> 31 #include <linux/compat.h> 32 #include <linux/jiffies.h> 33 #include <linux/interrupt.h> 34 35 #include <linux/mei.h> 36 37 #include "mei_dev.h" 38 #include "client.h" 39 40 /** 41 * mei_open - the open function 42 * 43 * @inode: pointer to inode structure 44 * @file: pointer to file structure 45 * 46 * Return: 0 on success, <0 on error 47 */ 48 static int mei_open(struct inode *inode, struct file *file) 49 { 50 struct mei_device *dev; 51 struct mei_cl *cl; 52 53 int err; 54 55 dev = container_of(inode->i_cdev, struct mei_device, cdev); 56 if (!dev) 57 return -ENODEV; 58 59 mutex_lock(&dev->device_lock); 60 61 if (dev->dev_state != MEI_DEV_ENABLED) { 62 dev_dbg(dev->dev, "dev_state != MEI_ENABLED dev_state = %s\n", 63 mei_dev_state_str(dev->dev_state)); 64 err = -ENODEV; 65 goto err_unlock; 66 } 67 68 cl = mei_cl_alloc_linked(dev); 69 if (IS_ERR(cl)) { 70 err = PTR_ERR(cl); 71 goto err_unlock; 72 } 73 74 cl->fp = file; 75 file->private_data = cl; 76 77 mutex_unlock(&dev->device_lock); 78 79 return nonseekable_open(inode, file); 80 81 err_unlock: 82 mutex_unlock(&dev->device_lock); 83 return err; 84 } 85 86 /** 87 * mei_release - the release function 88 * 89 * @inode: pointer to inode structure 90 * @file: pointer to file structure 91 * 92 * Return: 0 on success, <0 on error 93 */ 94 static int mei_release(struct inode *inode, struct file *file) 95 { 96 struct mei_cl *cl = file->private_data; 97 struct mei_device *dev; 98 int rets; 99 100 if (WARN_ON(!cl || !cl->dev)) 101 return -ENODEV; 102 103 dev = cl->dev; 104 105 mutex_lock(&dev->device_lock); 106 107 rets = mei_cl_disconnect(cl); 108 109 mei_cl_flush_queues(cl, file); 110 cl_dbg(dev, cl, "removing\n"); 111 112 mei_cl_unlink(cl); 113 114 file->private_data = NULL; 115 116 kfree(cl); 117 118 mutex_unlock(&dev->device_lock); 119 return rets; 120 } 121 122 123 /** 124 * mei_read - the read function. 125 * 126 * @file: pointer to file structure 127 * @ubuf: pointer to user buffer 128 * @length: buffer length 129 * @offset: data offset in buffer 130 * 131 * Return: >=0 data length on success , <0 on error 132 */ 133 static ssize_t mei_read(struct file *file, char __user *ubuf, 134 size_t length, loff_t *offset) 135 { 136 struct mei_cl *cl = file->private_data; 137 struct mei_device *dev; 138 struct mei_cl_cb *cb = NULL; 139 bool nonblock = !!(file->f_flags & O_NONBLOCK); 140 int rets; 141 142 if (WARN_ON(!cl || !cl->dev)) 143 return -ENODEV; 144 145 dev = cl->dev; 146 147 148 mutex_lock(&dev->device_lock); 149 if (dev->dev_state != MEI_DEV_ENABLED) { 150 rets = -ENODEV; 151 goto out; 152 } 153 154 if (length == 0) { 155 rets = 0; 156 goto out; 157 } 158 159 if (ubuf == NULL) { 160 rets = -EMSGSIZE; 161 goto out; 162 } 163 164 cb = mei_cl_read_cb(cl, file); 165 if (cb) 166 goto copy_buffer; 167 168 if (*offset > 0) 169 *offset = 0; 170 171 rets = mei_cl_read_start(cl, length, file); 172 if (rets && rets != -EBUSY) { 173 cl_dbg(dev, cl, "mei start read failure status = %d\n", rets); 174 goto out; 175 } 176 177 if (nonblock) { 178 rets = -EAGAIN; 179 goto out; 180 } 181 182 mutex_unlock(&dev->device_lock); 183 if (wait_event_interruptible(cl->rx_wait, 184 !list_empty(&cl->rd_completed) || 185 !mei_cl_is_connected(cl))) { 186 if (signal_pending(current)) 187 return -EINTR; 188 return -ERESTARTSYS; 189 } 190 mutex_lock(&dev->device_lock); 191 192 if (!mei_cl_is_connected(cl)) { 193 rets = -ENODEV; 194 goto out; 195 } 196 197 cb = mei_cl_read_cb(cl, file); 198 if (!cb) { 199 rets = 0; 200 goto out; 201 } 202 203 copy_buffer: 204 /* now copy the data to user space */ 205 if (cb->status) { 206 rets = cb->status; 207 cl_dbg(dev, cl, "read operation failed %d\n", rets); 208 goto free; 209 } 210 211 cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n", 212 cb->buf.size, cb->buf_idx, *offset); 213 if (*offset >= cb->buf_idx) { 214 rets = 0; 215 goto free; 216 } 217 218 /* length is being truncated to PAGE_SIZE, 219 * however buf_idx may point beyond that */ 220 length = min_t(size_t, length, cb->buf_idx - *offset); 221 222 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) { 223 dev_dbg(dev->dev, "failed to copy data to userland\n"); 224 rets = -EFAULT; 225 goto free; 226 } 227 228 rets = length; 229 *offset += length; 230 /* not all data was read, keep the cb */ 231 if (*offset < cb->buf_idx) 232 goto out; 233 234 free: 235 mei_io_cb_free(cb); 236 *offset = 0; 237 238 out: 239 cl_dbg(dev, cl, "end mei read rets = %d\n", rets); 240 mutex_unlock(&dev->device_lock); 241 return rets; 242 } 243 /** 244 * mei_write - the write function. 245 * 246 * @file: pointer to file structure 247 * @ubuf: pointer to user buffer 248 * @length: buffer length 249 * @offset: data offset in buffer 250 * 251 * Return: >=0 data length on success , <0 on error 252 */ 253 static ssize_t mei_write(struct file *file, const char __user *ubuf, 254 size_t length, loff_t *offset) 255 { 256 struct mei_cl *cl = file->private_data; 257 struct mei_cl_cb *cb; 258 struct mei_device *dev; 259 int rets; 260 261 if (WARN_ON(!cl || !cl->dev)) 262 return -ENODEV; 263 264 dev = cl->dev; 265 266 mutex_lock(&dev->device_lock); 267 268 if (dev->dev_state != MEI_DEV_ENABLED) { 269 rets = -ENODEV; 270 goto out; 271 } 272 273 if (!mei_cl_is_connected(cl)) { 274 cl_err(dev, cl, "is not connected"); 275 rets = -ENODEV; 276 goto out; 277 } 278 279 if (!mei_me_cl_is_active(cl->me_cl)) { 280 rets = -ENOTTY; 281 goto out; 282 } 283 284 if (length > mei_cl_mtu(cl)) { 285 rets = -EFBIG; 286 goto out; 287 } 288 289 if (length == 0) { 290 rets = 0; 291 goto out; 292 } 293 294 while (cl->tx_cb_queued >= dev->tx_queue_limit) { 295 if (file->f_flags & O_NONBLOCK) { 296 rets = -EAGAIN; 297 goto out; 298 } 299 mutex_unlock(&dev->device_lock); 300 rets = wait_event_interruptible(cl->tx_wait, 301 cl->writing_state == MEI_WRITE_COMPLETE || 302 (!mei_cl_is_connected(cl))); 303 mutex_lock(&dev->device_lock); 304 if (rets) { 305 if (signal_pending(current)) 306 rets = -EINTR; 307 goto out; 308 } 309 if (!mei_cl_is_connected(cl)) { 310 rets = -ENODEV; 311 goto out; 312 } 313 } 314 315 *offset = 0; 316 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file); 317 if (!cb) { 318 rets = -ENOMEM; 319 goto out; 320 } 321 322 rets = copy_from_user(cb->buf.data, ubuf, length); 323 if (rets) { 324 dev_dbg(dev->dev, "failed to copy data from userland\n"); 325 rets = -EFAULT; 326 mei_io_cb_free(cb); 327 goto out; 328 } 329 330 rets = mei_cl_write(cl, cb); 331 out: 332 mutex_unlock(&dev->device_lock); 333 return rets; 334 } 335 336 /** 337 * mei_ioctl_connect_client - the connect to fw client IOCTL function 338 * 339 * @file: private data of the file object 340 * @data: IOCTL connect data, input and output parameters 341 * 342 * Locking: called under "dev->device_lock" lock 343 * 344 * Return: 0 on success, <0 on failure. 345 */ 346 static int mei_ioctl_connect_client(struct file *file, 347 struct mei_connect_client_data *data) 348 { 349 struct mei_device *dev; 350 struct mei_client *client; 351 struct mei_me_client *me_cl; 352 struct mei_cl *cl; 353 int rets; 354 355 cl = file->private_data; 356 dev = cl->dev; 357 358 if (dev->dev_state != MEI_DEV_ENABLED) 359 return -ENODEV; 360 361 if (cl->state != MEI_FILE_INITIALIZING && 362 cl->state != MEI_FILE_DISCONNECTED) 363 return -EBUSY; 364 365 /* find ME client we're trying to connect to */ 366 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid); 367 if (!me_cl) { 368 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n", 369 &data->in_client_uuid); 370 rets = -ENOTTY; 371 goto end; 372 } 373 374 if (me_cl->props.fixed_address) { 375 bool forbidden = dev->override_fixed_address ? 376 !dev->allow_fixed_address : !dev->hbm_f_fa_supported; 377 if (forbidden) { 378 dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n", 379 &data->in_client_uuid); 380 rets = -ENOTTY; 381 goto end; 382 } 383 } 384 385 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n", 386 me_cl->client_id); 387 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n", 388 me_cl->props.protocol_version); 389 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n", 390 me_cl->props.max_msg_length); 391 392 /* prepare the output buffer */ 393 client = &data->out_client_properties; 394 client->max_msg_length = me_cl->props.max_msg_length; 395 client->protocol_version = me_cl->props.protocol_version; 396 dev_dbg(dev->dev, "Can connect?\n"); 397 398 rets = mei_cl_connect(cl, me_cl, file); 399 400 end: 401 mei_me_cl_put(me_cl); 402 return rets; 403 } 404 405 /** 406 * mei_ioctl_client_notify_request - 407 * propagate event notification request to client 408 * 409 * @file: pointer to file structure 410 * @request: 0 - disable, 1 - enable 411 * 412 * Return: 0 on success , <0 on error 413 */ 414 static int mei_ioctl_client_notify_request(const struct file *file, u32 request) 415 { 416 struct mei_cl *cl = file->private_data; 417 418 if (request != MEI_HBM_NOTIFICATION_START && 419 request != MEI_HBM_NOTIFICATION_STOP) 420 return -EINVAL; 421 422 return mei_cl_notify_request(cl, file, (u8)request); 423 } 424 425 /** 426 * mei_ioctl_client_notify_get - wait for notification request 427 * 428 * @file: pointer to file structure 429 * @notify_get: 0 - disable, 1 - enable 430 * 431 * Return: 0 on success , <0 on error 432 */ 433 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get) 434 { 435 struct mei_cl *cl = file->private_data; 436 bool notify_ev; 437 bool block = (file->f_flags & O_NONBLOCK) == 0; 438 int rets; 439 440 rets = mei_cl_notify_get(cl, block, ¬ify_ev); 441 if (rets) 442 return rets; 443 444 *notify_get = notify_ev ? 1 : 0; 445 return 0; 446 } 447 448 /** 449 * mei_ioctl - the IOCTL function 450 * 451 * @file: pointer to file structure 452 * @cmd: ioctl command 453 * @data: pointer to mei message structure 454 * 455 * Return: 0 on success , <0 on error 456 */ 457 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data) 458 { 459 struct mei_device *dev; 460 struct mei_cl *cl = file->private_data; 461 struct mei_connect_client_data connect_data; 462 u32 notify_get, notify_req; 463 int rets; 464 465 466 if (WARN_ON(!cl || !cl->dev)) 467 return -ENODEV; 468 469 dev = cl->dev; 470 471 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd); 472 473 mutex_lock(&dev->device_lock); 474 if (dev->dev_state != MEI_DEV_ENABLED) { 475 rets = -ENODEV; 476 goto out; 477 } 478 479 switch (cmd) { 480 case IOCTL_MEI_CONNECT_CLIENT: 481 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n"); 482 if (copy_from_user(&connect_data, (char __user *)data, 483 sizeof(struct mei_connect_client_data))) { 484 dev_dbg(dev->dev, "failed to copy data from userland\n"); 485 rets = -EFAULT; 486 goto out; 487 } 488 489 rets = mei_ioctl_connect_client(file, &connect_data); 490 if (rets) 491 goto out; 492 493 /* if all is ok, copying the data back to user. */ 494 if (copy_to_user((char __user *)data, &connect_data, 495 sizeof(struct mei_connect_client_data))) { 496 dev_dbg(dev->dev, "failed to copy data to userland\n"); 497 rets = -EFAULT; 498 goto out; 499 } 500 501 break; 502 503 case IOCTL_MEI_NOTIFY_SET: 504 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n"); 505 if (copy_from_user(¬ify_req, 506 (char __user *)data, sizeof(notify_req))) { 507 dev_dbg(dev->dev, "failed to copy data from userland\n"); 508 rets = -EFAULT; 509 goto out; 510 } 511 rets = mei_ioctl_client_notify_request(file, notify_req); 512 break; 513 514 case IOCTL_MEI_NOTIFY_GET: 515 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n"); 516 rets = mei_ioctl_client_notify_get(file, ¬ify_get); 517 if (rets) 518 goto out; 519 520 dev_dbg(dev->dev, "copy connect data to user\n"); 521 if (copy_to_user((char __user *)data, 522 ¬ify_get, sizeof(notify_get))) { 523 dev_dbg(dev->dev, "failed to copy data to userland\n"); 524 rets = -EFAULT; 525 goto out; 526 527 } 528 break; 529 530 default: 531 rets = -ENOIOCTLCMD; 532 } 533 534 out: 535 mutex_unlock(&dev->device_lock); 536 return rets; 537 } 538 539 /** 540 * mei_compat_ioctl - the compat IOCTL function 541 * 542 * @file: pointer to file structure 543 * @cmd: ioctl command 544 * @data: pointer to mei message structure 545 * 546 * Return: 0 on success , <0 on error 547 */ 548 #ifdef CONFIG_COMPAT 549 static long mei_compat_ioctl(struct file *file, 550 unsigned int cmd, unsigned long data) 551 { 552 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data)); 553 } 554 #endif 555 556 557 /** 558 * mei_poll - the poll function 559 * 560 * @file: pointer to file structure 561 * @wait: pointer to poll_table structure 562 * 563 * Return: poll mask 564 */ 565 static __poll_t mei_poll(struct file *file, poll_table *wait) 566 { 567 __poll_t req_events = poll_requested_events(wait); 568 struct mei_cl *cl = file->private_data; 569 struct mei_device *dev; 570 __poll_t mask = 0; 571 bool notify_en; 572 573 if (WARN_ON(!cl || !cl->dev)) 574 return EPOLLERR; 575 576 dev = cl->dev; 577 578 mutex_lock(&dev->device_lock); 579 580 notify_en = cl->notify_en && (req_events & EPOLLPRI); 581 582 if (dev->dev_state != MEI_DEV_ENABLED || 583 !mei_cl_is_connected(cl)) { 584 mask = EPOLLERR; 585 goto out; 586 } 587 588 if (notify_en) { 589 poll_wait(file, &cl->ev_wait, wait); 590 if (cl->notify_ev) 591 mask |= EPOLLPRI; 592 } 593 594 if (req_events & (EPOLLIN | EPOLLRDNORM)) { 595 poll_wait(file, &cl->rx_wait, wait); 596 597 if (!list_empty(&cl->rd_completed)) 598 mask |= EPOLLIN | EPOLLRDNORM; 599 else 600 mei_cl_read_start(cl, mei_cl_mtu(cl), file); 601 } 602 603 if (req_events & (POLLOUT | POLLWRNORM)) { 604 poll_wait(file, &cl->tx_wait, wait); 605 if (cl->tx_cb_queued < dev->tx_queue_limit) 606 mask |= POLLOUT | POLLWRNORM; 607 } 608 609 out: 610 mutex_unlock(&dev->device_lock); 611 return mask; 612 } 613 614 /** 615 * mei_cl_is_write_queued - check if the client has pending writes. 616 * 617 * @cl: writing host client 618 * 619 * Return: true if client is writing, false otherwise. 620 */ 621 static bool mei_cl_is_write_queued(struct mei_cl *cl) 622 { 623 struct mei_device *dev = cl->dev; 624 struct mei_cl_cb *cb; 625 626 list_for_each_entry(cb, &dev->write_list, list) 627 if (cb->cl == cl) 628 return true; 629 list_for_each_entry(cb, &dev->write_waiting_list, list) 630 if (cb->cl == cl) 631 return true; 632 return false; 633 } 634 635 /** 636 * mei_fsync - the fsync handler 637 * 638 * @fp: pointer to file structure 639 * @start: unused 640 * @end: unused 641 * @datasync: unused 642 * 643 * Return: 0 on success, -ENODEV if client is not connected 644 */ 645 static int mei_fsync(struct file *fp, loff_t start, loff_t end, int datasync) 646 { 647 struct mei_cl *cl = fp->private_data; 648 struct mei_device *dev; 649 int rets; 650 651 if (WARN_ON(!cl || !cl->dev)) 652 return -ENODEV; 653 654 dev = cl->dev; 655 656 mutex_lock(&dev->device_lock); 657 658 if (dev->dev_state != MEI_DEV_ENABLED || !mei_cl_is_connected(cl)) { 659 rets = -ENODEV; 660 goto out; 661 } 662 663 while (mei_cl_is_write_queued(cl)) { 664 mutex_unlock(&dev->device_lock); 665 rets = wait_event_interruptible(cl->tx_wait, 666 cl->writing_state == MEI_WRITE_COMPLETE || 667 !mei_cl_is_connected(cl)); 668 mutex_lock(&dev->device_lock); 669 if (rets) { 670 if (signal_pending(current)) 671 rets = -EINTR; 672 goto out; 673 } 674 if (!mei_cl_is_connected(cl)) { 675 rets = -ENODEV; 676 goto out; 677 } 678 } 679 rets = 0; 680 out: 681 mutex_unlock(&dev->device_lock); 682 return rets; 683 } 684 685 /** 686 * mei_fasync - asynchronous io support 687 * 688 * @fd: file descriptor 689 * @file: pointer to file structure 690 * @band: band bitmap 691 * 692 * Return: negative on error, 693 * 0 if it did no changes, 694 * and positive a process was added or deleted 695 */ 696 static int mei_fasync(int fd, struct file *file, int band) 697 { 698 699 struct mei_cl *cl = file->private_data; 700 701 if (!mei_cl_is_connected(cl)) 702 return -ENODEV; 703 704 return fasync_helper(fd, file, band, &cl->ev_async); 705 } 706 707 /** 708 * fw_status_show - mei device fw_status attribute show method 709 * 710 * @device: device pointer 711 * @attr: attribute pointer 712 * @buf: char out buffer 713 * 714 * Return: number of the bytes printed into buf or error 715 */ 716 static ssize_t fw_status_show(struct device *device, 717 struct device_attribute *attr, char *buf) 718 { 719 struct mei_device *dev = dev_get_drvdata(device); 720 struct mei_fw_status fw_status; 721 int err, i; 722 ssize_t cnt = 0; 723 724 mutex_lock(&dev->device_lock); 725 err = mei_fw_status(dev, &fw_status); 726 mutex_unlock(&dev->device_lock); 727 if (err) { 728 dev_err(device, "read fw_status error = %d\n", err); 729 return err; 730 } 731 732 for (i = 0; i < fw_status.count; i++) 733 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n", 734 fw_status.status[i]); 735 return cnt; 736 } 737 static DEVICE_ATTR_RO(fw_status); 738 739 /** 740 * hbm_ver_show - display HBM protocol version negotiated with FW 741 * 742 * @device: device pointer 743 * @attr: attribute pointer 744 * @buf: char out buffer 745 * 746 * Return: number of the bytes printed into buf or error 747 */ 748 static ssize_t hbm_ver_show(struct device *device, 749 struct device_attribute *attr, char *buf) 750 { 751 struct mei_device *dev = dev_get_drvdata(device); 752 struct hbm_version ver; 753 754 mutex_lock(&dev->device_lock); 755 ver = dev->version; 756 mutex_unlock(&dev->device_lock); 757 758 return sprintf(buf, "%u.%u\n", ver.major_version, ver.minor_version); 759 } 760 static DEVICE_ATTR_RO(hbm_ver); 761 762 /** 763 * hbm_ver_drv_show - display HBM protocol version advertised by driver 764 * 765 * @device: device pointer 766 * @attr: attribute pointer 767 * @buf: char out buffer 768 * 769 * Return: number of the bytes printed into buf or error 770 */ 771 static ssize_t hbm_ver_drv_show(struct device *device, 772 struct device_attribute *attr, char *buf) 773 { 774 return sprintf(buf, "%u.%u\n", HBM_MAJOR_VERSION, HBM_MINOR_VERSION); 775 } 776 static DEVICE_ATTR_RO(hbm_ver_drv); 777 778 static ssize_t tx_queue_limit_show(struct device *device, 779 struct device_attribute *attr, char *buf) 780 { 781 struct mei_device *dev = dev_get_drvdata(device); 782 u8 size = 0; 783 784 mutex_lock(&dev->device_lock); 785 size = dev->tx_queue_limit; 786 mutex_unlock(&dev->device_lock); 787 788 return snprintf(buf, PAGE_SIZE, "%u\n", size); 789 } 790 791 static ssize_t tx_queue_limit_store(struct device *device, 792 struct device_attribute *attr, 793 const char *buf, size_t count) 794 { 795 struct mei_device *dev = dev_get_drvdata(device); 796 u8 limit; 797 unsigned int inp; 798 int err; 799 800 err = kstrtouint(buf, 10, &inp); 801 if (err) 802 return err; 803 if (inp > MEI_TX_QUEUE_LIMIT_MAX || inp < MEI_TX_QUEUE_LIMIT_MIN) 804 return -EINVAL; 805 limit = inp; 806 807 mutex_lock(&dev->device_lock); 808 dev->tx_queue_limit = limit; 809 mutex_unlock(&dev->device_lock); 810 811 return count; 812 } 813 static DEVICE_ATTR_RW(tx_queue_limit); 814 815 static struct attribute *mei_attrs[] = { 816 &dev_attr_fw_status.attr, 817 &dev_attr_hbm_ver.attr, 818 &dev_attr_hbm_ver_drv.attr, 819 &dev_attr_tx_queue_limit.attr, 820 NULL 821 }; 822 ATTRIBUTE_GROUPS(mei); 823 824 /* 825 * file operations structure will be used for mei char device. 826 */ 827 static const struct file_operations mei_fops = { 828 .owner = THIS_MODULE, 829 .read = mei_read, 830 .unlocked_ioctl = mei_ioctl, 831 #ifdef CONFIG_COMPAT 832 .compat_ioctl = mei_compat_ioctl, 833 #endif 834 .open = mei_open, 835 .release = mei_release, 836 .write = mei_write, 837 .poll = mei_poll, 838 .fsync = mei_fsync, 839 .fasync = mei_fasync, 840 .llseek = no_llseek 841 }; 842 843 static struct class *mei_class; 844 static dev_t mei_devt; 845 #define MEI_MAX_DEVS MINORMASK 846 static DEFINE_MUTEX(mei_minor_lock); 847 static DEFINE_IDR(mei_idr); 848 849 /** 850 * mei_minor_get - obtain next free device minor number 851 * 852 * @dev: device pointer 853 * 854 * Return: allocated minor, or -ENOSPC if no free minor left 855 */ 856 static int mei_minor_get(struct mei_device *dev) 857 { 858 int ret; 859 860 mutex_lock(&mei_minor_lock); 861 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL); 862 if (ret >= 0) 863 dev->minor = ret; 864 else if (ret == -ENOSPC) 865 dev_err(dev->dev, "too many mei devices\n"); 866 867 mutex_unlock(&mei_minor_lock); 868 return ret; 869 } 870 871 /** 872 * mei_minor_free - mark device minor number as free 873 * 874 * @dev: device pointer 875 */ 876 static void mei_minor_free(struct mei_device *dev) 877 { 878 mutex_lock(&mei_minor_lock); 879 idr_remove(&mei_idr, dev->minor); 880 mutex_unlock(&mei_minor_lock); 881 } 882 883 int mei_register(struct mei_device *dev, struct device *parent) 884 { 885 struct device *clsdev; /* class device */ 886 int ret, devno; 887 888 ret = mei_minor_get(dev); 889 if (ret < 0) 890 return ret; 891 892 /* Fill in the data structures */ 893 devno = MKDEV(MAJOR(mei_devt), dev->minor); 894 cdev_init(&dev->cdev, &mei_fops); 895 dev->cdev.owner = parent->driver->owner; 896 897 /* Add the device */ 898 ret = cdev_add(&dev->cdev, devno, 1); 899 if (ret) { 900 dev_err(parent, "unable to add device %d:%d\n", 901 MAJOR(mei_devt), dev->minor); 902 goto err_dev_add; 903 } 904 905 clsdev = device_create_with_groups(mei_class, parent, devno, 906 dev, mei_groups, 907 "mei%d", dev->minor); 908 909 if (IS_ERR(clsdev)) { 910 dev_err(parent, "unable to create device %d:%d\n", 911 MAJOR(mei_devt), dev->minor); 912 ret = PTR_ERR(clsdev); 913 goto err_dev_create; 914 } 915 916 ret = mei_dbgfs_register(dev, dev_name(clsdev)); 917 if (ret) { 918 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret); 919 goto err_dev_dbgfs; 920 } 921 922 return 0; 923 924 err_dev_dbgfs: 925 device_destroy(mei_class, devno); 926 err_dev_create: 927 cdev_del(&dev->cdev); 928 err_dev_add: 929 mei_minor_free(dev); 930 return ret; 931 } 932 EXPORT_SYMBOL_GPL(mei_register); 933 934 void mei_deregister(struct mei_device *dev) 935 { 936 int devno; 937 938 devno = dev->cdev.dev; 939 cdev_del(&dev->cdev); 940 941 mei_dbgfs_deregister(dev); 942 943 device_destroy(mei_class, devno); 944 945 mei_minor_free(dev); 946 } 947 EXPORT_SYMBOL_GPL(mei_deregister); 948 949 static int __init mei_init(void) 950 { 951 int ret; 952 953 mei_class = class_create(THIS_MODULE, "mei"); 954 if (IS_ERR(mei_class)) { 955 pr_err("couldn't create class\n"); 956 ret = PTR_ERR(mei_class); 957 goto err; 958 } 959 960 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei"); 961 if (ret < 0) { 962 pr_err("unable to allocate char dev region\n"); 963 goto err_class; 964 } 965 966 ret = mei_cl_bus_init(); 967 if (ret < 0) { 968 pr_err("unable to initialize bus\n"); 969 goto err_chrdev; 970 } 971 972 return 0; 973 974 err_chrdev: 975 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS); 976 err_class: 977 class_destroy(mei_class); 978 err: 979 return ret; 980 } 981 982 static void __exit mei_exit(void) 983 { 984 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS); 985 class_destroy(mei_class); 986 mei_cl_bus_exit(); 987 } 988 989 module_init(mei_init); 990 module_exit(mei_exit); 991 992 MODULE_AUTHOR("Intel Corporation"); 993 MODULE_DESCRIPTION("Intel(R) Management Engine Interface"); 994 MODULE_LICENSE("GPL v2"); 995 996