1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * ipmi_devintf.c 4 * 5 * Linux device interface for the IPMI message handler. 6 * 7 * Author: MontaVista Software, Inc. 8 * Corey Minyard <minyard@mvista.com> 9 * source@mvista.com 10 * 11 * Copyright 2002 MontaVista Software Inc. 12 */ 13 14 #include <linux/module.h> 15 #include <linux/moduleparam.h> 16 #include <linux/errno.h> 17 #include <linux/poll.h> 18 #include <linux/sched.h> 19 #include <linux/spinlock.h> 20 #include <linux/slab.h> 21 #include <linux/ipmi.h> 22 #include <linux/mutex.h> 23 #include <linux/init.h> 24 #include <linux/device.h> 25 #include <linux/compat.h> 26 27 struct ipmi_file_private 28 { 29 struct ipmi_user *user; 30 spinlock_t recv_msg_lock; 31 struct list_head recv_msgs; 32 struct fasync_struct *fasync_queue; 33 wait_queue_head_t wait; 34 struct mutex recv_mutex; 35 int default_retries; 36 unsigned int default_retry_time_ms; 37 }; 38 39 static void file_receive_handler(struct ipmi_recv_msg *msg, 40 void *handler_data) 41 { 42 struct ipmi_file_private *priv = handler_data; 43 int was_empty; 44 unsigned long flags; 45 46 spin_lock_irqsave(&priv->recv_msg_lock, flags); 47 was_empty = list_empty(&priv->recv_msgs); 48 list_add_tail(&msg->link, &priv->recv_msgs); 49 spin_unlock_irqrestore(&priv->recv_msg_lock, flags); 50 51 if (was_empty) { 52 wake_up_interruptible(&priv->wait); 53 kill_fasync(&priv->fasync_queue, SIGIO, POLL_IN); 54 } 55 } 56 57 static __poll_t ipmi_poll(struct file *file, poll_table *wait) 58 { 59 struct ipmi_file_private *priv = file->private_data; 60 __poll_t mask = 0; 61 unsigned long flags; 62 63 poll_wait(file, &priv->wait, wait); 64 65 spin_lock_irqsave(&priv->recv_msg_lock, flags); 66 67 if (!list_empty(&priv->recv_msgs)) 68 mask |= (EPOLLIN | EPOLLRDNORM); 69 70 spin_unlock_irqrestore(&priv->recv_msg_lock, flags); 71 72 return mask; 73 } 74 75 static int ipmi_fasync(int fd, struct file *file, int on) 76 { 77 struct ipmi_file_private *priv = file->private_data; 78 79 return fasync_helper(fd, file, on, &priv->fasync_queue); 80 } 81 82 static const struct ipmi_user_hndl ipmi_hndlrs = 83 { 84 .ipmi_recv_hndl = file_receive_handler, 85 }; 86 87 static int ipmi_open(struct inode *inode, struct file *file) 88 { 89 int if_num = iminor(inode); 90 int rv; 91 struct ipmi_file_private *priv; 92 93 priv = kmalloc(sizeof(*priv), GFP_KERNEL); 94 if (!priv) 95 return -ENOMEM; 96 97 rv = ipmi_create_user(if_num, 98 &ipmi_hndlrs, 99 priv, 100 &priv->user); 101 if (rv) { 102 kfree(priv); 103 goto out; 104 } 105 106 file->private_data = priv; 107 108 spin_lock_init(&priv->recv_msg_lock); 109 INIT_LIST_HEAD(&priv->recv_msgs); 110 init_waitqueue_head(&priv->wait); 111 priv->fasync_queue = NULL; 112 mutex_init(&priv->recv_mutex); 113 114 /* Use the low-level defaults. */ 115 priv->default_retries = -1; 116 priv->default_retry_time_ms = 0; 117 118 out: 119 return rv; 120 } 121 122 static int ipmi_release(struct inode *inode, struct file *file) 123 { 124 struct ipmi_file_private *priv = file->private_data; 125 int rv; 126 struct ipmi_recv_msg *msg, *next; 127 128 rv = ipmi_destroy_user(priv->user); 129 if (rv) 130 return rv; 131 132 list_for_each_entry_safe(msg, next, &priv->recv_msgs, link) 133 ipmi_free_recv_msg(msg); 134 135 kfree(priv); 136 137 return 0; 138 } 139 140 static int handle_send_req(struct ipmi_user *user, 141 struct ipmi_req *req, 142 int retries, 143 unsigned int retry_time_ms) 144 { 145 int rv; 146 struct ipmi_addr addr; 147 struct kernel_ipmi_msg msg; 148 149 if (req->addr_len > sizeof(struct ipmi_addr)) 150 return -EINVAL; 151 152 if (copy_from_user(&addr, req->addr, req->addr_len)) 153 return -EFAULT; 154 155 msg.netfn = req->msg.netfn; 156 msg.cmd = req->msg.cmd; 157 msg.data_len = req->msg.data_len; 158 msg.data = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL); 159 if (!msg.data) 160 return -ENOMEM; 161 162 /* From here out we cannot return, we must jump to "out" for 163 error exits to free msgdata. */ 164 165 rv = ipmi_validate_addr(&addr, req->addr_len); 166 if (rv) 167 goto out; 168 169 if (req->msg.data != NULL) { 170 if (req->msg.data_len > IPMI_MAX_MSG_LENGTH) { 171 rv = -EMSGSIZE; 172 goto out; 173 } 174 175 if (copy_from_user(msg.data, 176 req->msg.data, 177 req->msg.data_len)) { 178 rv = -EFAULT; 179 goto out; 180 } 181 } else { 182 msg.data_len = 0; 183 } 184 185 rv = ipmi_request_settime(user, 186 &addr, 187 req->msgid, 188 &msg, 189 NULL, 190 0, 191 retries, 192 retry_time_ms); 193 out: 194 kfree(msg.data); 195 return rv; 196 } 197 198 static int handle_recv(struct ipmi_file_private *priv, 199 bool trunc, struct ipmi_recv *rsp, 200 int (*copyout)(struct ipmi_recv *, void __user *), 201 void __user *to) 202 { 203 int addr_len; 204 struct list_head *entry; 205 struct ipmi_recv_msg *msg; 206 unsigned long flags; 207 int rv = 0, rv2 = 0; 208 209 /* We claim a mutex because we don't want two 210 users getting something from the queue at a time. 211 Since we have to release the spinlock before we can 212 copy the data to the user, it's possible another 213 user will grab something from the queue, too. Then 214 the messages might get out of order if something 215 fails and the message gets put back onto the 216 queue. This mutex prevents that problem. */ 217 mutex_lock(&priv->recv_mutex); 218 219 /* Grab the message off the list. */ 220 spin_lock_irqsave(&priv->recv_msg_lock, flags); 221 if (list_empty(&(priv->recv_msgs))) { 222 spin_unlock_irqrestore(&priv->recv_msg_lock, flags); 223 rv = -EAGAIN; 224 goto recv_err; 225 } 226 entry = priv->recv_msgs.next; 227 msg = list_entry(entry, struct ipmi_recv_msg, link); 228 list_del(entry); 229 spin_unlock_irqrestore(&priv->recv_msg_lock, flags); 230 231 addr_len = ipmi_addr_length(msg->addr.addr_type); 232 if (rsp->addr_len < addr_len) { 233 rv = -EINVAL; 234 goto recv_putback_on_err; 235 } 236 237 if (copy_to_user(rsp->addr, &msg->addr, addr_len)) { 238 rv = -EFAULT; 239 goto recv_putback_on_err; 240 } 241 rsp->addr_len = addr_len; 242 243 rsp->recv_type = msg->recv_type; 244 rsp->msgid = msg->msgid; 245 rsp->msg.netfn = msg->msg.netfn; 246 rsp->msg.cmd = msg->msg.cmd; 247 248 if (msg->msg.data_len > 0) { 249 if (rsp->msg.data_len < msg->msg.data_len) { 250 rv2 = -EMSGSIZE; 251 if (trunc) 252 msg->msg.data_len = rsp->msg.data_len; 253 else 254 goto recv_putback_on_err; 255 } 256 257 if (copy_to_user(rsp->msg.data, 258 msg->msg.data, 259 msg->msg.data_len)) { 260 rv = -EFAULT; 261 goto recv_putback_on_err; 262 } 263 rsp->msg.data_len = msg->msg.data_len; 264 } else { 265 rsp->msg.data_len = 0; 266 } 267 268 rv = copyout(rsp, to); 269 if (rv) 270 goto recv_putback_on_err; 271 272 mutex_unlock(&priv->recv_mutex); 273 ipmi_free_recv_msg(msg); 274 return rv2; 275 276 recv_putback_on_err: 277 /* If we got an error, put the message back onto 278 the head of the queue. */ 279 spin_lock_irqsave(&priv->recv_msg_lock, flags); 280 list_add(entry, &priv->recv_msgs); 281 spin_unlock_irqrestore(&priv->recv_msg_lock, flags); 282 recv_err: 283 mutex_unlock(&priv->recv_mutex); 284 return rv; 285 } 286 287 static int copyout_recv(struct ipmi_recv *rsp, void __user *to) 288 { 289 return copy_to_user(to, rsp, sizeof(struct ipmi_recv)) ? -EFAULT : 0; 290 } 291 292 static long ipmi_ioctl(struct file *file, 293 unsigned int cmd, 294 unsigned long data) 295 { 296 int rv = -EINVAL; 297 struct ipmi_file_private *priv = file->private_data; 298 void __user *arg = (void __user *)data; 299 300 switch (cmd) 301 { 302 case IPMICTL_SEND_COMMAND: 303 { 304 struct ipmi_req req; 305 int retries; 306 unsigned int retry_time_ms; 307 308 if (copy_from_user(&req, arg, sizeof(req))) { 309 rv = -EFAULT; 310 break; 311 } 312 313 mutex_lock(&priv->recv_mutex); 314 retries = priv->default_retries; 315 retry_time_ms = priv->default_retry_time_ms; 316 mutex_unlock(&priv->recv_mutex); 317 318 rv = handle_send_req(priv->user, &req, retries, retry_time_ms); 319 break; 320 } 321 322 case IPMICTL_SEND_COMMAND_SETTIME: 323 { 324 struct ipmi_req_settime req; 325 326 if (copy_from_user(&req, arg, sizeof(req))) { 327 rv = -EFAULT; 328 break; 329 } 330 331 rv = handle_send_req(priv->user, 332 &req.req, 333 req.retries, 334 req.retry_time_ms); 335 break; 336 } 337 338 case IPMICTL_RECEIVE_MSG: 339 case IPMICTL_RECEIVE_MSG_TRUNC: 340 { 341 struct ipmi_recv rsp; 342 343 if (copy_from_user(&rsp, arg, sizeof(rsp))) 344 rv = -EFAULT; 345 else 346 rv = handle_recv(priv, cmd == IPMICTL_RECEIVE_MSG_TRUNC, 347 &rsp, copyout_recv, arg); 348 break; 349 } 350 351 case IPMICTL_REGISTER_FOR_CMD: 352 { 353 struct ipmi_cmdspec val; 354 355 if (copy_from_user(&val, arg, sizeof(val))) { 356 rv = -EFAULT; 357 break; 358 } 359 360 rv = ipmi_register_for_cmd(priv->user, val.netfn, val.cmd, 361 IPMI_CHAN_ALL); 362 break; 363 } 364 365 case IPMICTL_UNREGISTER_FOR_CMD: 366 { 367 struct ipmi_cmdspec val; 368 369 if (copy_from_user(&val, arg, sizeof(val))) { 370 rv = -EFAULT; 371 break; 372 } 373 374 rv = ipmi_unregister_for_cmd(priv->user, val.netfn, val.cmd, 375 IPMI_CHAN_ALL); 376 break; 377 } 378 379 case IPMICTL_REGISTER_FOR_CMD_CHANS: 380 { 381 struct ipmi_cmdspec_chans val; 382 383 if (copy_from_user(&val, arg, sizeof(val))) { 384 rv = -EFAULT; 385 break; 386 } 387 388 rv = ipmi_register_for_cmd(priv->user, val.netfn, val.cmd, 389 val.chans); 390 break; 391 } 392 393 case IPMICTL_UNREGISTER_FOR_CMD_CHANS: 394 { 395 struct ipmi_cmdspec_chans val; 396 397 if (copy_from_user(&val, arg, sizeof(val))) { 398 rv = -EFAULT; 399 break; 400 } 401 402 rv = ipmi_unregister_for_cmd(priv->user, val.netfn, val.cmd, 403 val.chans); 404 break; 405 } 406 407 case IPMICTL_SET_GETS_EVENTS_CMD: 408 { 409 int val; 410 411 if (copy_from_user(&val, arg, sizeof(val))) { 412 rv = -EFAULT; 413 break; 414 } 415 416 rv = ipmi_set_gets_events(priv->user, val); 417 break; 418 } 419 420 /* The next four are legacy, not per-channel. */ 421 case IPMICTL_SET_MY_ADDRESS_CMD: 422 { 423 unsigned int val; 424 425 if (copy_from_user(&val, arg, sizeof(val))) { 426 rv = -EFAULT; 427 break; 428 } 429 430 rv = ipmi_set_my_address(priv->user, 0, val); 431 break; 432 } 433 434 case IPMICTL_GET_MY_ADDRESS_CMD: 435 { 436 unsigned int val; 437 unsigned char rval; 438 439 rv = ipmi_get_my_address(priv->user, 0, &rval); 440 if (rv) 441 break; 442 443 val = rval; 444 445 if (copy_to_user(arg, &val, sizeof(val))) { 446 rv = -EFAULT; 447 break; 448 } 449 break; 450 } 451 452 case IPMICTL_SET_MY_LUN_CMD: 453 { 454 unsigned int val; 455 456 if (copy_from_user(&val, arg, sizeof(val))) { 457 rv = -EFAULT; 458 break; 459 } 460 461 rv = ipmi_set_my_LUN(priv->user, 0, val); 462 break; 463 } 464 465 case IPMICTL_GET_MY_LUN_CMD: 466 { 467 unsigned int val; 468 unsigned char rval; 469 470 rv = ipmi_get_my_LUN(priv->user, 0, &rval); 471 if (rv) 472 break; 473 474 val = rval; 475 476 if (copy_to_user(arg, &val, sizeof(val))) { 477 rv = -EFAULT; 478 break; 479 } 480 break; 481 } 482 483 case IPMICTL_SET_MY_CHANNEL_ADDRESS_CMD: 484 { 485 struct ipmi_channel_lun_address_set val; 486 487 if (copy_from_user(&val, arg, sizeof(val))) { 488 rv = -EFAULT; 489 break; 490 } 491 492 return ipmi_set_my_address(priv->user, val.channel, val.value); 493 break; 494 } 495 496 case IPMICTL_GET_MY_CHANNEL_ADDRESS_CMD: 497 { 498 struct ipmi_channel_lun_address_set val; 499 500 if (copy_from_user(&val, arg, sizeof(val))) { 501 rv = -EFAULT; 502 break; 503 } 504 505 rv = ipmi_get_my_address(priv->user, val.channel, &val.value); 506 if (rv) 507 break; 508 509 if (copy_to_user(arg, &val, sizeof(val))) { 510 rv = -EFAULT; 511 break; 512 } 513 break; 514 } 515 516 case IPMICTL_SET_MY_CHANNEL_LUN_CMD: 517 { 518 struct ipmi_channel_lun_address_set val; 519 520 if (copy_from_user(&val, arg, sizeof(val))) { 521 rv = -EFAULT; 522 break; 523 } 524 525 rv = ipmi_set_my_LUN(priv->user, val.channel, val.value); 526 break; 527 } 528 529 case IPMICTL_GET_MY_CHANNEL_LUN_CMD: 530 { 531 struct ipmi_channel_lun_address_set val; 532 533 if (copy_from_user(&val, arg, sizeof(val))) { 534 rv = -EFAULT; 535 break; 536 } 537 538 rv = ipmi_get_my_LUN(priv->user, val.channel, &val.value); 539 if (rv) 540 break; 541 542 if (copy_to_user(arg, &val, sizeof(val))) { 543 rv = -EFAULT; 544 break; 545 } 546 break; 547 } 548 549 case IPMICTL_SET_TIMING_PARMS_CMD: 550 { 551 struct ipmi_timing_parms parms; 552 553 if (copy_from_user(&parms, arg, sizeof(parms))) { 554 rv = -EFAULT; 555 break; 556 } 557 558 mutex_lock(&priv->recv_mutex); 559 priv->default_retries = parms.retries; 560 priv->default_retry_time_ms = parms.retry_time_ms; 561 mutex_unlock(&priv->recv_mutex); 562 rv = 0; 563 break; 564 } 565 566 case IPMICTL_GET_TIMING_PARMS_CMD: 567 { 568 struct ipmi_timing_parms parms; 569 570 mutex_lock(&priv->recv_mutex); 571 parms.retries = priv->default_retries; 572 parms.retry_time_ms = priv->default_retry_time_ms; 573 mutex_unlock(&priv->recv_mutex); 574 575 if (copy_to_user(arg, &parms, sizeof(parms))) { 576 rv = -EFAULT; 577 break; 578 } 579 580 rv = 0; 581 break; 582 } 583 584 case IPMICTL_GET_MAINTENANCE_MODE_CMD: 585 { 586 int mode; 587 588 mode = ipmi_get_maintenance_mode(priv->user); 589 if (copy_to_user(arg, &mode, sizeof(mode))) { 590 rv = -EFAULT; 591 break; 592 } 593 rv = 0; 594 break; 595 } 596 597 case IPMICTL_SET_MAINTENANCE_MODE_CMD: 598 { 599 int mode; 600 601 if (copy_from_user(&mode, arg, sizeof(mode))) { 602 rv = -EFAULT; 603 break; 604 } 605 rv = ipmi_set_maintenance_mode(priv->user, mode); 606 break; 607 } 608 609 default: 610 rv = -ENOTTY; 611 break; 612 } 613 614 return rv; 615 } 616 617 #ifdef CONFIG_COMPAT 618 /* 619 * The following code contains code for supporting 32-bit compatible 620 * ioctls on 64-bit kernels. This allows running 32-bit apps on the 621 * 64-bit kernel 622 */ 623 #define COMPAT_IPMICTL_SEND_COMMAND \ 624 _IOR(IPMI_IOC_MAGIC, 13, struct compat_ipmi_req) 625 #define COMPAT_IPMICTL_SEND_COMMAND_SETTIME \ 626 _IOR(IPMI_IOC_MAGIC, 21, struct compat_ipmi_req_settime) 627 #define COMPAT_IPMICTL_RECEIVE_MSG \ 628 _IOWR(IPMI_IOC_MAGIC, 12, struct compat_ipmi_recv) 629 #define COMPAT_IPMICTL_RECEIVE_MSG_TRUNC \ 630 _IOWR(IPMI_IOC_MAGIC, 11, struct compat_ipmi_recv) 631 632 struct compat_ipmi_msg { 633 u8 netfn; 634 u8 cmd; 635 u16 data_len; 636 compat_uptr_t data; 637 }; 638 639 struct compat_ipmi_req { 640 compat_uptr_t addr; 641 compat_uint_t addr_len; 642 compat_long_t msgid; 643 struct compat_ipmi_msg msg; 644 }; 645 646 struct compat_ipmi_recv { 647 compat_int_t recv_type; 648 compat_uptr_t addr; 649 compat_uint_t addr_len; 650 compat_long_t msgid; 651 struct compat_ipmi_msg msg; 652 }; 653 654 struct compat_ipmi_req_settime { 655 struct compat_ipmi_req req; 656 compat_int_t retries; 657 compat_uint_t retry_time_ms; 658 }; 659 660 /* 661 * Define some helper functions for copying IPMI data 662 */ 663 static void get_compat_ipmi_msg(struct ipmi_msg *p64, 664 struct compat_ipmi_msg *p32) 665 { 666 p64->netfn = p32->netfn; 667 p64->cmd = p32->cmd; 668 p64->data_len = p32->data_len; 669 p64->data = compat_ptr(p32->data); 670 } 671 672 static void get_compat_ipmi_req(struct ipmi_req *p64, 673 struct compat_ipmi_req *p32) 674 { 675 p64->addr = compat_ptr(p32->addr); 676 p64->addr_len = p32->addr_len; 677 p64->msgid = p32->msgid; 678 get_compat_ipmi_msg(&p64->msg, &p32->msg); 679 } 680 681 static void get_compat_ipmi_req_settime(struct ipmi_req_settime *p64, 682 struct compat_ipmi_req_settime *p32) 683 { 684 get_compat_ipmi_req(&p64->req, &p32->req); 685 p64->retries = p32->retries; 686 p64->retry_time_ms = p32->retry_time_ms; 687 } 688 689 static void get_compat_ipmi_recv(struct ipmi_recv *p64, 690 struct compat_ipmi_recv *p32) 691 { 692 memset(p64, 0, sizeof(struct ipmi_recv)); 693 p64->recv_type = p32->recv_type; 694 p64->addr = compat_ptr(p32->addr); 695 p64->addr_len = p32->addr_len; 696 p64->msgid = p32->msgid; 697 get_compat_ipmi_msg(&p64->msg, &p32->msg); 698 } 699 700 static int copyout_recv32(struct ipmi_recv *p64, void __user *to) 701 { 702 struct compat_ipmi_recv v32; 703 memset(&v32, 0, sizeof(struct compat_ipmi_recv)); 704 v32.recv_type = p64->recv_type; 705 v32.addr = ptr_to_compat(p64->addr); 706 v32.addr_len = p64->addr_len; 707 v32.msgid = p64->msgid; 708 v32.msg.netfn = p64->msg.netfn; 709 v32.msg.cmd = p64->msg.cmd; 710 v32.msg.data_len = p64->msg.data_len; 711 v32.msg.data = ptr_to_compat(p64->msg.data); 712 return copy_to_user(to, &v32, sizeof(v32)) ? -EFAULT : 0; 713 } 714 715 /* 716 * Handle compatibility ioctls 717 */ 718 static long compat_ipmi_ioctl(struct file *filep, unsigned int cmd, 719 unsigned long arg) 720 { 721 struct ipmi_file_private *priv = filep->private_data; 722 723 switch(cmd) { 724 case COMPAT_IPMICTL_SEND_COMMAND: 725 { 726 struct ipmi_req rp; 727 struct compat_ipmi_req r32; 728 int retries; 729 unsigned int retry_time_ms; 730 731 if (copy_from_user(&r32, compat_ptr(arg), sizeof(r32))) 732 return -EFAULT; 733 734 get_compat_ipmi_req(&rp, &r32); 735 736 mutex_lock(&priv->recv_mutex); 737 retries = priv->default_retries; 738 retry_time_ms = priv->default_retry_time_ms; 739 mutex_unlock(&priv->recv_mutex); 740 741 return handle_send_req(priv->user, &rp, 742 retries, retry_time_ms); 743 } 744 case COMPAT_IPMICTL_SEND_COMMAND_SETTIME: 745 { 746 struct ipmi_req_settime sp; 747 struct compat_ipmi_req_settime sp32; 748 749 if (copy_from_user(&sp32, compat_ptr(arg), sizeof(sp32))) 750 return -EFAULT; 751 752 get_compat_ipmi_req_settime(&sp, &sp32); 753 754 return handle_send_req(priv->user, &sp.req, 755 sp.retries, sp.retry_time_ms); 756 } 757 case COMPAT_IPMICTL_RECEIVE_MSG: 758 case COMPAT_IPMICTL_RECEIVE_MSG_TRUNC: 759 { 760 struct ipmi_recv recv64; 761 struct compat_ipmi_recv recv32; 762 763 if (copy_from_user(&recv32, compat_ptr(arg), sizeof(recv32))) 764 return -EFAULT; 765 766 get_compat_ipmi_recv(&recv64, &recv32); 767 768 return handle_recv(priv, 769 cmd == COMPAT_IPMICTL_RECEIVE_MSG_TRUNC, 770 &recv64, copyout_recv32, compat_ptr(arg)); 771 } 772 default: 773 return ipmi_ioctl(filep, cmd, arg); 774 } 775 } 776 #endif 777 778 static const struct file_operations ipmi_fops = { 779 .owner = THIS_MODULE, 780 .unlocked_ioctl = ipmi_ioctl, 781 #ifdef CONFIG_COMPAT 782 .compat_ioctl = compat_ipmi_ioctl, 783 #endif 784 .open = ipmi_open, 785 .release = ipmi_release, 786 .fasync = ipmi_fasync, 787 .poll = ipmi_poll, 788 .llseek = noop_llseek, 789 }; 790 791 #define DEVICE_NAME "ipmidev" 792 793 static int ipmi_major; 794 module_param(ipmi_major, int, 0); 795 MODULE_PARM_DESC(ipmi_major, "Sets the major number of the IPMI device. By" 796 " default, or if you set it to zero, it will choose the next" 797 " available device. Setting it to -1 will disable the" 798 " interface. Other values will set the major device number" 799 " to that value."); 800 801 /* Keep track of the devices that are registered. */ 802 struct ipmi_reg_list { 803 dev_t dev; 804 struct list_head link; 805 }; 806 static LIST_HEAD(reg_list); 807 static DEFINE_MUTEX(reg_list_mutex); 808 809 static struct class *ipmi_class; 810 811 static void ipmi_new_smi(int if_num, struct device *device) 812 { 813 dev_t dev = MKDEV(ipmi_major, if_num); 814 struct ipmi_reg_list *entry; 815 816 entry = kmalloc(sizeof(*entry), GFP_KERNEL); 817 if (!entry) { 818 pr_err("ipmi_devintf: Unable to create the ipmi class device link\n"); 819 return; 820 } 821 entry->dev = dev; 822 823 mutex_lock(®_list_mutex); 824 device_create(ipmi_class, device, dev, NULL, "ipmi%d", if_num); 825 list_add(&entry->link, ®_list); 826 mutex_unlock(®_list_mutex); 827 } 828 829 static void ipmi_smi_gone(int if_num) 830 { 831 dev_t dev = MKDEV(ipmi_major, if_num); 832 struct ipmi_reg_list *entry; 833 834 mutex_lock(®_list_mutex); 835 list_for_each_entry(entry, ®_list, link) { 836 if (entry->dev == dev) { 837 list_del(&entry->link); 838 kfree(entry); 839 break; 840 } 841 } 842 device_destroy(ipmi_class, dev); 843 mutex_unlock(®_list_mutex); 844 } 845 846 static struct ipmi_smi_watcher smi_watcher = 847 { 848 .owner = THIS_MODULE, 849 .new_smi = ipmi_new_smi, 850 .smi_gone = ipmi_smi_gone, 851 }; 852 853 static int __init init_ipmi_devintf(void) 854 { 855 int rv; 856 857 if (ipmi_major < 0) 858 return -EINVAL; 859 860 pr_info("ipmi device interface\n"); 861 862 ipmi_class = class_create(THIS_MODULE, "ipmi"); 863 if (IS_ERR(ipmi_class)) { 864 pr_err("ipmi: can't register device class\n"); 865 return PTR_ERR(ipmi_class); 866 } 867 868 rv = register_chrdev(ipmi_major, DEVICE_NAME, &ipmi_fops); 869 if (rv < 0) { 870 class_destroy(ipmi_class); 871 pr_err("ipmi: can't get major %d\n", ipmi_major); 872 return rv; 873 } 874 875 if (ipmi_major == 0) { 876 ipmi_major = rv; 877 } 878 879 rv = ipmi_smi_watcher_register(&smi_watcher); 880 if (rv) { 881 unregister_chrdev(ipmi_major, DEVICE_NAME); 882 class_destroy(ipmi_class); 883 pr_warn("ipmi: can't register smi watcher\n"); 884 return rv; 885 } 886 887 return 0; 888 } 889 module_init(init_ipmi_devintf); 890 891 static void __exit cleanup_ipmi(void) 892 { 893 struct ipmi_reg_list *entry, *entry2; 894 mutex_lock(®_list_mutex); 895 list_for_each_entry_safe(entry, entry2, ®_list, link) { 896 list_del(&entry->link); 897 device_destroy(ipmi_class, entry->dev); 898 kfree(entry); 899 } 900 mutex_unlock(®_list_mutex); 901 class_destroy(ipmi_class); 902 ipmi_smi_watcher_unregister(&smi_watcher); 903 unregister_chrdev(ipmi_major, DEVICE_NAME); 904 } 905 module_exit(cleanup_ipmi); 906 907 MODULE_LICENSE("GPL"); 908 MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>"); 909 MODULE_DESCRIPTION("Linux device interface for the IPMI message handler."); 910