1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2021, Linaro Ltd <loic.poulain@linaro.org> */ 3 4 #include <linux/err.h> 5 #include <linux/errno.h> 6 #include <linux/debugfs.h> 7 #include <linux/fs.h> 8 #include <linux/init.h> 9 #include <linux/idr.h> 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/poll.h> 13 #include <linux/skbuff.h> 14 #include <linux/slab.h> 15 #include <linux/types.h> 16 #include <linux/uaccess.h> 17 #include <linux/termios.h> 18 #include <linux/wwan.h> 19 #include <net/rtnetlink.h> 20 #include <uapi/linux/wwan.h> 21 22 /* Maximum number of minors in use */ 23 #define WWAN_MAX_MINORS (1 << MINORBITS) 24 25 static DEFINE_MUTEX(wwan_register_lock); /* WWAN device create|remove lock */ 26 static DEFINE_IDA(minors); /* minors for WWAN port chardevs */ 27 static DEFINE_IDA(wwan_dev_ids); /* for unique WWAN device IDs */ 28 static struct class *wwan_class; 29 static int wwan_major; 30 static struct dentry *wwan_debugfs_dir; 31 32 #define to_wwan_dev(d) container_of(d, struct wwan_device, dev) 33 #define to_wwan_port(d) container_of(d, struct wwan_port, dev) 34 35 /* WWAN port flags */ 36 #define WWAN_PORT_TX_OFF 0 37 38 /** 39 * struct wwan_device - The structure that defines a WWAN device 40 * 41 * @id: WWAN device unique ID. 42 * @dev: Underlying device. 43 * @port_id: Current available port ID to pick. 44 * @ops: wwan device ops 45 * @ops_ctxt: context to pass to ops 46 * @debugfs_dir: WWAN device debugfs dir 47 */ 48 struct wwan_device { 49 unsigned int id; 50 struct device dev; 51 atomic_t port_id; 52 const struct wwan_ops *ops; 53 void *ops_ctxt; 54 #ifdef CONFIG_WWAN_DEBUGFS 55 struct dentry *debugfs_dir; 56 #endif 57 }; 58 59 /** 60 * struct wwan_port - The structure that defines a WWAN port 61 * @type: Port type 62 * @start_count: Port start counter 63 * @flags: Store port state and capabilities 64 * @ops: Pointer to WWAN port operations 65 * @ops_lock: Protect port ops 66 * @dev: Underlying device 67 * @rxq: Buffer inbound queue 68 * @waitqueue: The waitqueue for port fops (read/write/poll) 69 * @data_lock: Port specific data access serialization 70 * @headroom_len: SKB reserved headroom size 71 * @frag_len: Length to fragment packet 72 * @at_data: AT port specific data 73 */ 74 struct wwan_port { 75 enum wwan_port_type type; 76 unsigned int start_count; 77 unsigned long flags; 78 const struct wwan_port_ops *ops; 79 struct mutex ops_lock; /* Serialize ops + protect against removal */ 80 struct device dev; 81 struct sk_buff_head rxq; 82 wait_queue_head_t waitqueue; 83 struct mutex data_lock; /* Port specific data access serialization */ 84 size_t headroom_len; 85 size_t frag_len; 86 union { 87 struct { 88 struct ktermios termios; 89 int mdmbits; 90 } at_data; 91 }; 92 }; 93 94 static ssize_t index_show(struct device *dev, struct device_attribute *attr, char *buf) 95 { 96 struct wwan_device *wwan = to_wwan_dev(dev); 97 98 return sprintf(buf, "%d\n", wwan->id); 99 } 100 static DEVICE_ATTR_RO(index); 101 102 static struct attribute *wwan_dev_attrs[] = { 103 &dev_attr_index.attr, 104 NULL, 105 }; 106 ATTRIBUTE_GROUPS(wwan_dev); 107 108 static void wwan_dev_destroy(struct device *dev) 109 { 110 struct wwan_device *wwandev = to_wwan_dev(dev); 111 112 ida_free(&wwan_dev_ids, wwandev->id); 113 kfree(wwandev); 114 } 115 116 static const struct device_type wwan_dev_type = { 117 .name = "wwan_dev", 118 .release = wwan_dev_destroy, 119 .groups = wwan_dev_groups, 120 }; 121 122 static int wwan_dev_parent_match(struct device *dev, const void *parent) 123 { 124 return (dev->type == &wwan_dev_type && 125 (dev->parent == parent || dev == parent)); 126 } 127 128 static struct wwan_device *wwan_dev_get_by_parent(struct device *parent) 129 { 130 struct device *dev; 131 132 dev = class_find_device(wwan_class, NULL, parent, wwan_dev_parent_match); 133 if (!dev) 134 return ERR_PTR(-ENODEV); 135 136 return to_wwan_dev(dev); 137 } 138 139 static int wwan_dev_name_match(struct device *dev, const void *name) 140 { 141 return dev->type == &wwan_dev_type && 142 strcmp(dev_name(dev), name) == 0; 143 } 144 145 static struct wwan_device *wwan_dev_get_by_name(const char *name) 146 { 147 struct device *dev; 148 149 dev = class_find_device(wwan_class, NULL, name, wwan_dev_name_match); 150 if (!dev) 151 return ERR_PTR(-ENODEV); 152 153 return to_wwan_dev(dev); 154 } 155 156 #ifdef CONFIG_WWAN_DEBUGFS 157 struct dentry *wwan_get_debugfs_dir(struct device *parent) 158 { 159 struct wwan_device *wwandev; 160 161 wwandev = wwan_dev_get_by_parent(parent); 162 if (IS_ERR(wwandev)) 163 return ERR_CAST(wwandev); 164 165 return wwandev->debugfs_dir; 166 } 167 EXPORT_SYMBOL_GPL(wwan_get_debugfs_dir); 168 169 static int wwan_dev_debugfs_match(struct device *dev, const void *dir) 170 { 171 struct wwan_device *wwandev; 172 173 if (dev->type != &wwan_dev_type) 174 return 0; 175 176 wwandev = to_wwan_dev(dev); 177 178 return wwandev->debugfs_dir == dir; 179 } 180 181 static struct wwan_device *wwan_dev_get_by_debugfs(struct dentry *dir) 182 { 183 struct device *dev; 184 185 dev = class_find_device(wwan_class, NULL, dir, wwan_dev_debugfs_match); 186 if (!dev) 187 return ERR_PTR(-ENODEV); 188 189 return to_wwan_dev(dev); 190 } 191 192 void wwan_put_debugfs_dir(struct dentry *dir) 193 { 194 struct wwan_device *wwandev = wwan_dev_get_by_debugfs(dir); 195 196 if (WARN_ON(IS_ERR(wwandev))) 197 return; 198 199 /* wwan_dev_get_by_debugfs() also got a reference */ 200 put_device(&wwandev->dev); 201 put_device(&wwandev->dev); 202 } 203 EXPORT_SYMBOL_GPL(wwan_put_debugfs_dir); 204 #endif 205 206 /* This function allocates and registers a new WWAN device OR if a WWAN device 207 * already exist for the given parent, it gets a reference and return it. 208 * This function is not exported (for now), it is called indirectly via 209 * wwan_create_port(). 210 */ 211 static struct wwan_device *wwan_create_dev(struct device *parent) 212 { 213 struct wwan_device *wwandev; 214 int err, id; 215 216 /* The 'find-alloc-register' operation must be protected against 217 * concurrent execution, a WWAN device is possibly shared between 218 * multiple callers or concurrently unregistered from wwan_remove_dev(). 219 */ 220 mutex_lock(&wwan_register_lock); 221 222 /* If wwandev already exists, return it */ 223 wwandev = wwan_dev_get_by_parent(parent); 224 if (!IS_ERR(wwandev)) 225 goto done_unlock; 226 227 id = ida_alloc(&wwan_dev_ids, GFP_KERNEL); 228 if (id < 0) { 229 wwandev = ERR_PTR(id); 230 goto done_unlock; 231 } 232 233 wwandev = kzalloc(sizeof(*wwandev), GFP_KERNEL); 234 if (!wwandev) { 235 wwandev = ERR_PTR(-ENOMEM); 236 ida_free(&wwan_dev_ids, id); 237 goto done_unlock; 238 } 239 240 wwandev->dev.parent = parent; 241 wwandev->dev.class = wwan_class; 242 wwandev->dev.type = &wwan_dev_type; 243 wwandev->id = id; 244 dev_set_name(&wwandev->dev, "wwan%d", wwandev->id); 245 246 err = device_register(&wwandev->dev); 247 if (err) { 248 put_device(&wwandev->dev); 249 wwandev = ERR_PTR(err); 250 goto done_unlock; 251 } 252 253 #ifdef CONFIG_WWAN_DEBUGFS 254 wwandev->debugfs_dir = 255 debugfs_create_dir(kobject_name(&wwandev->dev.kobj), 256 wwan_debugfs_dir); 257 #endif 258 259 done_unlock: 260 mutex_unlock(&wwan_register_lock); 261 262 return wwandev; 263 } 264 265 static int is_wwan_child(struct device *dev, void *data) 266 { 267 return dev->class == wwan_class; 268 } 269 270 static void wwan_remove_dev(struct wwan_device *wwandev) 271 { 272 int ret; 273 274 /* Prevent concurrent picking from wwan_create_dev */ 275 mutex_lock(&wwan_register_lock); 276 277 /* WWAN device is created and registered (get+add) along with its first 278 * child port, and subsequent port registrations only grab a reference 279 * (get). The WWAN device must then be unregistered (del+put) along with 280 * its last port, and reference simply dropped (put) otherwise. In the 281 * same fashion, we must not unregister it when the ops are still there. 282 */ 283 if (wwandev->ops) 284 ret = 1; 285 else 286 ret = device_for_each_child(&wwandev->dev, NULL, is_wwan_child); 287 288 if (!ret) { 289 #ifdef CONFIG_WWAN_DEBUGFS 290 debugfs_remove_recursive(wwandev->debugfs_dir); 291 #endif 292 device_unregister(&wwandev->dev); 293 } else { 294 put_device(&wwandev->dev); 295 } 296 297 mutex_unlock(&wwan_register_lock); 298 } 299 300 /* ------- WWAN port management ------- */ 301 302 static const struct { 303 const char * const name; /* Port type name */ 304 const char * const devsuf; /* Port devce name suffix */ 305 } wwan_port_types[WWAN_PORT_MAX + 1] = { 306 [WWAN_PORT_AT] = { 307 .name = "AT", 308 .devsuf = "at", 309 }, 310 [WWAN_PORT_MBIM] = { 311 .name = "MBIM", 312 .devsuf = "mbim", 313 }, 314 [WWAN_PORT_QMI] = { 315 .name = "QMI", 316 .devsuf = "qmi", 317 }, 318 [WWAN_PORT_QCDM] = { 319 .name = "QCDM", 320 .devsuf = "qcdm", 321 }, 322 [WWAN_PORT_FIREHOSE] = { 323 .name = "FIREHOSE", 324 .devsuf = "firehose", 325 }, 326 [WWAN_PORT_XMMRPC] = { 327 .name = "XMMRPC", 328 .devsuf = "xmmrpc", 329 }, 330 }; 331 332 static ssize_t type_show(struct device *dev, struct device_attribute *attr, 333 char *buf) 334 { 335 struct wwan_port *port = to_wwan_port(dev); 336 337 return sprintf(buf, "%s\n", wwan_port_types[port->type].name); 338 } 339 static DEVICE_ATTR_RO(type); 340 341 static struct attribute *wwan_port_attrs[] = { 342 &dev_attr_type.attr, 343 NULL, 344 }; 345 ATTRIBUTE_GROUPS(wwan_port); 346 347 static void wwan_port_destroy(struct device *dev) 348 { 349 struct wwan_port *port = to_wwan_port(dev); 350 351 ida_free(&minors, MINOR(port->dev.devt)); 352 mutex_destroy(&port->data_lock); 353 mutex_destroy(&port->ops_lock); 354 kfree(port); 355 } 356 357 static const struct device_type wwan_port_dev_type = { 358 .name = "wwan_port", 359 .release = wwan_port_destroy, 360 .groups = wwan_port_groups, 361 }; 362 363 static int wwan_port_minor_match(struct device *dev, const void *minor) 364 { 365 return (dev->type == &wwan_port_dev_type && 366 MINOR(dev->devt) == *(unsigned int *)minor); 367 } 368 369 static struct wwan_port *wwan_port_get_by_minor(unsigned int minor) 370 { 371 struct device *dev; 372 373 dev = class_find_device(wwan_class, NULL, &minor, wwan_port_minor_match); 374 if (!dev) 375 return ERR_PTR(-ENODEV); 376 377 return to_wwan_port(dev); 378 } 379 380 /* Allocate and set unique name based on passed format 381 * 382 * Name allocation approach is highly inspired by the __dev_alloc_name() 383 * function. 384 * 385 * To avoid names collision, the caller must prevent the new port device 386 * registration as well as concurrent invocation of this function. 387 */ 388 static int __wwan_port_dev_assign_name(struct wwan_port *port, const char *fmt) 389 { 390 struct wwan_device *wwandev = to_wwan_dev(port->dev.parent); 391 const unsigned int max_ports = PAGE_SIZE * 8; 392 struct class_dev_iter iter; 393 unsigned long *idmap; 394 struct device *dev; 395 char buf[0x20]; 396 int id; 397 398 idmap = (unsigned long *)get_zeroed_page(GFP_KERNEL); 399 if (!idmap) 400 return -ENOMEM; 401 402 /* Collect ids of same name format ports */ 403 class_dev_iter_init(&iter, wwan_class, NULL, &wwan_port_dev_type); 404 while ((dev = class_dev_iter_next(&iter))) { 405 if (dev->parent != &wwandev->dev) 406 continue; 407 if (sscanf(dev_name(dev), fmt, &id) != 1) 408 continue; 409 if (id < 0 || id >= max_ports) 410 continue; 411 set_bit(id, idmap); 412 } 413 class_dev_iter_exit(&iter); 414 415 /* Allocate unique id */ 416 id = find_first_zero_bit(idmap, max_ports); 417 free_page((unsigned long)idmap); 418 419 snprintf(buf, sizeof(buf), fmt, id); /* Name generation */ 420 421 dev = device_find_child_by_name(&wwandev->dev, buf); 422 if (dev) { 423 put_device(dev); 424 return -ENFILE; 425 } 426 427 return dev_set_name(&port->dev, buf); 428 } 429 430 struct wwan_port *wwan_create_port(struct device *parent, 431 enum wwan_port_type type, 432 const struct wwan_port_ops *ops, 433 struct wwan_port_caps *caps, 434 void *drvdata) 435 { 436 struct wwan_device *wwandev; 437 struct wwan_port *port; 438 char namefmt[0x20]; 439 int minor, err; 440 441 if (type > WWAN_PORT_MAX || !ops) 442 return ERR_PTR(-EINVAL); 443 444 /* A port is always a child of a WWAN device, retrieve (allocate or 445 * pick) the WWAN device based on the provided parent device. 446 */ 447 wwandev = wwan_create_dev(parent); 448 if (IS_ERR(wwandev)) 449 return ERR_CAST(wwandev); 450 451 /* A port is exposed as character device, get a minor */ 452 minor = ida_alloc_range(&minors, 0, WWAN_MAX_MINORS - 1, GFP_KERNEL); 453 if (minor < 0) { 454 err = minor; 455 goto error_wwandev_remove; 456 } 457 458 port = kzalloc(sizeof(*port), GFP_KERNEL); 459 if (!port) { 460 err = -ENOMEM; 461 ida_free(&minors, minor); 462 goto error_wwandev_remove; 463 } 464 465 port->type = type; 466 port->ops = ops; 467 port->frag_len = caps ? caps->frag_len : SIZE_MAX; 468 port->headroom_len = caps ? caps->headroom_len : 0; 469 mutex_init(&port->ops_lock); 470 skb_queue_head_init(&port->rxq); 471 init_waitqueue_head(&port->waitqueue); 472 mutex_init(&port->data_lock); 473 474 port->dev.parent = &wwandev->dev; 475 port->dev.class = wwan_class; 476 port->dev.type = &wwan_port_dev_type; 477 port->dev.devt = MKDEV(wwan_major, minor); 478 dev_set_drvdata(&port->dev, drvdata); 479 480 /* allocate unique name based on wwan device id, port type and number */ 481 snprintf(namefmt, sizeof(namefmt), "wwan%u%s%%d", wwandev->id, 482 wwan_port_types[port->type].devsuf); 483 484 /* Serialize ports registration */ 485 mutex_lock(&wwan_register_lock); 486 487 __wwan_port_dev_assign_name(port, namefmt); 488 err = device_register(&port->dev); 489 490 mutex_unlock(&wwan_register_lock); 491 492 if (err) 493 goto error_put_device; 494 495 return port; 496 497 error_put_device: 498 put_device(&port->dev); 499 error_wwandev_remove: 500 wwan_remove_dev(wwandev); 501 502 return ERR_PTR(err); 503 } 504 EXPORT_SYMBOL_GPL(wwan_create_port); 505 506 void wwan_remove_port(struct wwan_port *port) 507 { 508 struct wwan_device *wwandev = to_wwan_dev(port->dev.parent); 509 510 mutex_lock(&port->ops_lock); 511 if (port->start_count) 512 port->ops->stop(port); 513 port->ops = NULL; /* Prevent any new port operations (e.g. from fops) */ 514 mutex_unlock(&port->ops_lock); 515 516 wake_up_interruptible(&port->waitqueue); 517 518 skb_queue_purge(&port->rxq); 519 dev_set_drvdata(&port->dev, NULL); 520 device_unregister(&port->dev); 521 522 /* Release related wwan device */ 523 wwan_remove_dev(wwandev); 524 } 525 EXPORT_SYMBOL_GPL(wwan_remove_port); 526 527 void wwan_port_rx(struct wwan_port *port, struct sk_buff *skb) 528 { 529 skb_queue_tail(&port->rxq, skb); 530 wake_up_interruptible(&port->waitqueue); 531 } 532 EXPORT_SYMBOL_GPL(wwan_port_rx); 533 534 void wwan_port_txon(struct wwan_port *port) 535 { 536 clear_bit(WWAN_PORT_TX_OFF, &port->flags); 537 wake_up_interruptible(&port->waitqueue); 538 } 539 EXPORT_SYMBOL_GPL(wwan_port_txon); 540 541 void wwan_port_txoff(struct wwan_port *port) 542 { 543 set_bit(WWAN_PORT_TX_OFF, &port->flags); 544 } 545 EXPORT_SYMBOL_GPL(wwan_port_txoff); 546 547 void *wwan_port_get_drvdata(struct wwan_port *port) 548 { 549 return dev_get_drvdata(&port->dev); 550 } 551 EXPORT_SYMBOL_GPL(wwan_port_get_drvdata); 552 553 static int wwan_port_op_start(struct wwan_port *port) 554 { 555 int ret = 0; 556 557 mutex_lock(&port->ops_lock); 558 if (!port->ops) { /* Port got unplugged */ 559 ret = -ENODEV; 560 goto out_unlock; 561 } 562 563 /* If port is already started, don't start again */ 564 if (!port->start_count) 565 ret = port->ops->start(port); 566 567 if (!ret) 568 port->start_count++; 569 570 out_unlock: 571 mutex_unlock(&port->ops_lock); 572 573 return ret; 574 } 575 576 static void wwan_port_op_stop(struct wwan_port *port) 577 { 578 mutex_lock(&port->ops_lock); 579 port->start_count--; 580 if (!port->start_count) { 581 if (port->ops) 582 port->ops->stop(port); 583 skb_queue_purge(&port->rxq); 584 } 585 mutex_unlock(&port->ops_lock); 586 } 587 588 static int wwan_port_op_tx(struct wwan_port *port, struct sk_buff *skb, 589 bool nonblock) 590 { 591 int ret; 592 593 mutex_lock(&port->ops_lock); 594 if (!port->ops) { /* Port got unplugged */ 595 ret = -ENODEV; 596 goto out_unlock; 597 } 598 599 if (nonblock || !port->ops->tx_blocking) 600 ret = port->ops->tx(port, skb); 601 else 602 ret = port->ops->tx_blocking(port, skb); 603 604 out_unlock: 605 mutex_unlock(&port->ops_lock); 606 607 return ret; 608 } 609 610 static bool is_read_blocked(struct wwan_port *port) 611 { 612 return skb_queue_empty(&port->rxq) && port->ops; 613 } 614 615 static bool is_write_blocked(struct wwan_port *port) 616 { 617 return test_bit(WWAN_PORT_TX_OFF, &port->flags) && port->ops; 618 } 619 620 static int wwan_wait_rx(struct wwan_port *port, bool nonblock) 621 { 622 if (!is_read_blocked(port)) 623 return 0; 624 625 if (nonblock) 626 return -EAGAIN; 627 628 if (wait_event_interruptible(port->waitqueue, !is_read_blocked(port))) 629 return -ERESTARTSYS; 630 631 return 0; 632 } 633 634 static int wwan_wait_tx(struct wwan_port *port, bool nonblock) 635 { 636 if (!is_write_blocked(port)) 637 return 0; 638 639 if (nonblock) 640 return -EAGAIN; 641 642 if (wait_event_interruptible(port->waitqueue, !is_write_blocked(port))) 643 return -ERESTARTSYS; 644 645 return 0; 646 } 647 648 static int wwan_port_fops_open(struct inode *inode, struct file *file) 649 { 650 struct wwan_port *port; 651 int err = 0; 652 653 port = wwan_port_get_by_minor(iminor(inode)); 654 if (IS_ERR(port)) 655 return PTR_ERR(port); 656 657 file->private_data = port; 658 stream_open(inode, file); 659 660 err = wwan_port_op_start(port); 661 if (err) 662 put_device(&port->dev); 663 664 return err; 665 } 666 667 static int wwan_port_fops_release(struct inode *inode, struct file *filp) 668 { 669 struct wwan_port *port = filp->private_data; 670 671 wwan_port_op_stop(port); 672 put_device(&port->dev); 673 674 return 0; 675 } 676 677 static ssize_t wwan_port_fops_read(struct file *filp, char __user *buf, 678 size_t count, loff_t *ppos) 679 { 680 struct wwan_port *port = filp->private_data; 681 struct sk_buff *skb; 682 size_t copied; 683 int ret; 684 685 ret = wwan_wait_rx(port, !!(filp->f_flags & O_NONBLOCK)); 686 if (ret) 687 return ret; 688 689 skb = skb_dequeue(&port->rxq); 690 if (!skb) 691 return -EIO; 692 693 copied = min_t(size_t, count, skb->len); 694 if (copy_to_user(buf, skb->data, copied)) { 695 kfree_skb(skb); 696 return -EFAULT; 697 } 698 skb_pull(skb, copied); 699 700 /* skb is not fully consumed, keep it in the queue */ 701 if (skb->len) 702 skb_queue_head(&port->rxq, skb); 703 else 704 consume_skb(skb); 705 706 return copied; 707 } 708 709 static ssize_t wwan_port_fops_write(struct file *filp, const char __user *buf, 710 size_t count, loff_t *offp) 711 { 712 struct sk_buff *skb, *head = NULL, *tail = NULL; 713 struct wwan_port *port = filp->private_data; 714 size_t frag_len, remain = count; 715 int ret; 716 717 ret = wwan_wait_tx(port, !!(filp->f_flags & O_NONBLOCK)); 718 if (ret) 719 return ret; 720 721 do { 722 frag_len = min(remain, port->frag_len); 723 skb = alloc_skb(frag_len + port->headroom_len, GFP_KERNEL); 724 if (!skb) { 725 ret = -ENOMEM; 726 goto freeskb; 727 } 728 skb_reserve(skb, port->headroom_len); 729 730 if (!head) { 731 head = skb; 732 } else if (!tail) { 733 skb_shinfo(head)->frag_list = skb; 734 tail = skb; 735 } else { 736 tail->next = skb; 737 tail = skb; 738 } 739 740 if (copy_from_user(skb_put(skb, frag_len), buf + count - remain, frag_len)) { 741 ret = -EFAULT; 742 goto freeskb; 743 } 744 745 if (skb != head) { 746 head->data_len += skb->len; 747 head->len += skb->len; 748 head->truesize += skb->truesize; 749 } 750 } while (remain -= frag_len); 751 752 ret = wwan_port_op_tx(port, head, !!(filp->f_flags & O_NONBLOCK)); 753 if (!ret) 754 return count; 755 756 freeskb: 757 kfree_skb(head); 758 return ret; 759 } 760 761 static __poll_t wwan_port_fops_poll(struct file *filp, poll_table *wait) 762 { 763 struct wwan_port *port = filp->private_data; 764 __poll_t mask = 0; 765 766 poll_wait(filp, &port->waitqueue, wait); 767 768 mutex_lock(&port->ops_lock); 769 if (port->ops && port->ops->tx_poll) 770 mask |= port->ops->tx_poll(port, filp, wait); 771 else if (!is_write_blocked(port)) 772 mask |= EPOLLOUT | EPOLLWRNORM; 773 if (!is_read_blocked(port)) 774 mask |= EPOLLIN | EPOLLRDNORM; 775 if (!port->ops) 776 mask |= EPOLLHUP | EPOLLERR; 777 mutex_unlock(&port->ops_lock); 778 779 return mask; 780 } 781 782 /* Implements minimalistic stub terminal IOCTLs support */ 783 static long wwan_port_fops_at_ioctl(struct wwan_port *port, unsigned int cmd, 784 unsigned long arg) 785 { 786 int ret = 0; 787 788 mutex_lock(&port->data_lock); 789 790 switch (cmd) { 791 case TCFLSH: 792 break; 793 794 case TCGETS: 795 if (copy_to_user((void __user *)arg, &port->at_data.termios, 796 sizeof(struct termios))) 797 ret = -EFAULT; 798 break; 799 800 case TCSETS: 801 case TCSETSW: 802 case TCSETSF: 803 if (copy_from_user(&port->at_data.termios, (void __user *)arg, 804 sizeof(struct termios))) 805 ret = -EFAULT; 806 break; 807 808 #ifdef TCGETS2 809 case TCGETS2: 810 if (copy_to_user((void __user *)arg, &port->at_data.termios, 811 sizeof(struct termios2))) 812 ret = -EFAULT; 813 break; 814 815 case TCSETS2: 816 case TCSETSW2: 817 case TCSETSF2: 818 if (copy_from_user(&port->at_data.termios, (void __user *)arg, 819 sizeof(struct termios2))) 820 ret = -EFAULT; 821 break; 822 #endif 823 824 case TIOCMGET: 825 ret = put_user(port->at_data.mdmbits, (int __user *)arg); 826 break; 827 828 case TIOCMSET: 829 case TIOCMBIC: 830 case TIOCMBIS: { 831 int mdmbits; 832 833 if (copy_from_user(&mdmbits, (int __user *)arg, sizeof(int))) { 834 ret = -EFAULT; 835 break; 836 } 837 if (cmd == TIOCMBIC) 838 port->at_data.mdmbits &= ~mdmbits; 839 else if (cmd == TIOCMBIS) 840 port->at_data.mdmbits |= mdmbits; 841 else 842 port->at_data.mdmbits = mdmbits; 843 break; 844 } 845 846 default: 847 ret = -ENOIOCTLCMD; 848 } 849 850 mutex_unlock(&port->data_lock); 851 852 return ret; 853 } 854 855 static long wwan_port_fops_ioctl(struct file *filp, unsigned int cmd, 856 unsigned long arg) 857 { 858 struct wwan_port *port = filp->private_data; 859 int res; 860 861 if (port->type == WWAN_PORT_AT) { /* AT port specific IOCTLs */ 862 res = wwan_port_fops_at_ioctl(port, cmd, arg); 863 if (res != -ENOIOCTLCMD) 864 return res; 865 } 866 867 switch (cmd) { 868 case TIOCINQ: { /* aka SIOCINQ aka FIONREAD */ 869 unsigned long flags; 870 struct sk_buff *skb; 871 int amount = 0; 872 873 spin_lock_irqsave(&port->rxq.lock, flags); 874 skb_queue_walk(&port->rxq, skb) 875 amount += skb->len; 876 spin_unlock_irqrestore(&port->rxq.lock, flags); 877 878 return put_user(amount, (int __user *)arg); 879 } 880 881 default: 882 return -ENOIOCTLCMD; 883 } 884 } 885 886 static const struct file_operations wwan_port_fops = { 887 .owner = THIS_MODULE, 888 .open = wwan_port_fops_open, 889 .release = wwan_port_fops_release, 890 .read = wwan_port_fops_read, 891 .write = wwan_port_fops_write, 892 .poll = wwan_port_fops_poll, 893 .unlocked_ioctl = wwan_port_fops_ioctl, 894 #ifdef CONFIG_COMPAT 895 .compat_ioctl = compat_ptr_ioctl, 896 #endif 897 .llseek = noop_llseek, 898 }; 899 900 static int wwan_rtnl_validate(struct nlattr *tb[], struct nlattr *data[], 901 struct netlink_ext_ack *extack) 902 { 903 if (!data) 904 return -EINVAL; 905 906 if (!tb[IFLA_PARENT_DEV_NAME]) 907 return -EINVAL; 908 909 if (!data[IFLA_WWAN_LINK_ID]) 910 return -EINVAL; 911 912 return 0; 913 } 914 915 static struct device_type wwan_type = { .name = "wwan" }; 916 917 static struct net_device *wwan_rtnl_alloc(struct nlattr *tb[], 918 const char *ifname, 919 unsigned char name_assign_type, 920 unsigned int num_tx_queues, 921 unsigned int num_rx_queues) 922 { 923 const char *devname = nla_data(tb[IFLA_PARENT_DEV_NAME]); 924 struct wwan_device *wwandev = wwan_dev_get_by_name(devname); 925 struct net_device *dev; 926 unsigned int priv_size; 927 928 if (IS_ERR(wwandev)) 929 return ERR_CAST(wwandev); 930 931 /* only supported if ops were registered (not just ports) */ 932 if (!wwandev->ops) { 933 dev = ERR_PTR(-EOPNOTSUPP); 934 goto out; 935 } 936 937 priv_size = sizeof(struct wwan_netdev_priv) + wwandev->ops->priv_size; 938 dev = alloc_netdev_mqs(priv_size, ifname, name_assign_type, 939 wwandev->ops->setup, num_tx_queues, num_rx_queues); 940 941 if (dev) { 942 SET_NETDEV_DEV(dev, &wwandev->dev); 943 SET_NETDEV_DEVTYPE(dev, &wwan_type); 944 } 945 946 out: 947 /* release the reference */ 948 put_device(&wwandev->dev); 949 return dev; 950 } 951 952 static int wwan_rtnl_newlink(struct net *src_net, struct net_device *dev, 953 struct nlattr *tb[], struct nlattr *data[], 954 struct netlink_ext_ack *extack) 955 { 956 struct wwan_device *wwandev = wwan_dev_get_by_parent(dev->dev.parent); 957 u32 link_id = nla_get_u32(data[IFLA_WWAN_LINK_ID]); 958 struct wwan_netdev_priv *priv = netdev_priv(dev); 959 int ret; 960 961 if (IS_ERR(wwandev)) 962 return PTR_ERR(wwandev); 963 964 /* shouldn't have a netdev (left) with us as parent so WARN */ 965 if (WARN_ON(!wwandev->ops)) { 966 ret = -EOPNOTSUPP; 967 goto out; 968 } 969 970 priv->link_id = link_id; 971 if (wwandev->ops->newlink) 972 ret = wwandev->ops->newlink(wwandev->ops_ctxt, dev, 973 link_id, extack); 974 else 975 ret = register_netdevice(dev); 976 977 out: 978 /* release the reference */ 979 put_device(&wwandev->dev); 980 return ret; 981 } 982 983 static void wwan_rtnl_dellink(struct net_device *dev, struct list_head *head) 984 { 985 struct wwan_device *wwandev = wwan_dev_get_by_parent(dev->dev.parent); 986 987 if (IS_ERR(wwandev)) 988 return; 989 990 /* shouldn't have a netdev (left) with us as parent so WARN */ 991 if (WARN_ON(!wwandev->ops)) 992 goto out; 993 994 if (wwandev->ops->dellink) 995 wwandev->ops->dellink(wwandev->ops_ctxt, dev, head); 996 else 997 unregister_netdevice_queue(dev, head); 998 999 out: 1000 /* release the reference */ 1001 put_device(&wwandev->dev); 1002 } 1003 1004 static size_t wwan_rtnl_get_size(const struct net_device *dev) 1005 { 1006 return 1007 nla_total_size(4) + /* IFLA_WWAN_LINK_ID */ 1008 0; 1009 } 1010 1011 static int wwan_rtnl_fill_info(struct sk_buff *skb, 1012 const struct net_device *dev) 1013 { 1014 struct wwan_netdev_priv *priv = netdev_priv(dev); 1015 1016 if (nla_put_u32(skb, IFLA_WWAN_LINK_ID, priv->link_id)) 1017 goto nla_put_failure; 1018 1019 return 0; 1020 1021 nla_put_failure: 1022 return -EMSGSIZE; 1023 } 1024 1025 static const struct nla_policy wwan_rtnl_policy[IFLA_WWAN_MAX + 1] = { 1026 [IFLA_WWAN_LINK_ID] = { .type = NLA_U32 }, 1027 }; 1028 1029 static struct rtnl_link_ops wwan_rtnl_link_ops __read_mostly = { 1030 .kind = "wwan", 1031 .maxtype = __IFLA_WWAN_MAX, 1032 .alloc = wwan_rtnl_alloc, 1033 .validate = wwan_rtnl_validate, 1034 .newlink = wwan_rtnl_newlink, 1035 .dellink = wwan_rtnl_dellink, 1036 .get_size = wwan_rtnl_get_size, 1037 .fill_info = wwan_rtnl_fill_info, 1038 .policy = wwan_rtnl_policy, 1039 }; 1040 1041 static void wwan_create_default_link(struct wwan_device *wwandev, 1042 u32 def_link_id) 1043 { 1044 struct nlattr *tb[IFLA_MAX + 1], *linkinfo[IFLA_INFO_MAX + 1]; 1045 struct nlattr *data[IFLA_WWAN_MAX + 1]; 1046 struct net_device *dev; 1047 struct nlmsghdr *nlh; 1048 struct sk_buff *msg; 1049 1050 /* Forge attributes required to create a WWAN netdev. We first 1051 * build a netlink message and then parse it. This looks 1052 * odd, but such approach is less error prone. 1053 */ 1054 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 1055 if (WARN_ON(!msg)) 1056 return; 1057 nlh = nlmsg_put(msg, 0, 0, RTM_NEWLINK, 0, 0); 1058 if (WARN_ON(!nlh)) 1059 goto free_attrs; 1060 1061 if (nla_put_string(msg, IFLA_PARENT_DEV_NAME, dev_name(&wwandev->dev))) 1062 goto free_attrs; 1063 tb[IFLA_LINKINFO] = nla_nest_start(msg, IFLA_LINKINFO); 1064 if (!tb[IFLA_LINKINFO]) 1065 goto free_attrs; 1066 linkinfo[IFLA_INFO_DATA] = nla_nest_start(msg, IFLA_INFO_DATA); 1067 if (!linkinfo[IFLA_INFO_DATA]) 1068 goto free_attrs; 1069 if (nla_put_u32(msg, IFLA_WWAN_LINK_ID, def_link_id)) 1070 goto free_attrs; 1071 nla_nest_end(msg, linkinfo[IFLA_INFO_DATA]); 1072 nla_nest_end(msg, tb[IFLA_LINKINFO]); 1073 1074 nlmsg_end(msg, nlh); 1075 1076 /* The next three parsing calls can not fail */ 1077 nlmsg_parse_deprecated(nlh, 0, tb, IFLA_MAX, NULL, NULL); 1078 nla_parse_nested_deprecated(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO], 1079 NULL, NULL); 1080 nla_parse_nested_deprecated(data, IFLA_WWAN_MAX, 1081 linkinfo[IFLA_INFO_DATA], NULL, NULL); 1082 1083 rtnl_lock(); 1084 1085 dev = rtnl_create_link(&init_net, "wwan%d", NET_NAME_ENUM, 1086 &wwan_rtnl_link_ops, tb, NULL); 1087 if (WARN_ON(IS_ERR(dev))) 1088 goto unlock; 1089 1090 if (WARN_ON(wwan_rtnl_newlink(&init_net, dev, tb, data, NULL))) { 1091 free_netdev(dev); 1092 goto unlock; 1093 } 1094 1095 rtnl_configure_link(dev, NULL, 0, NULL); /* Link initialized, notify new link */ 1096 1097 unlock: 1098 rtnl_unlock(); 1099 1100 free_attrs: 1101 nlmsg_free(msg); 1102 } 1103 1104 /** 1105 * wwan_register_ops - register WWAN device ops 1106 * @parent: Device to use as parent and shared by all WWAN ports and 1107 * created netdevs 1108 * @ops: operations to register 1109 * @ctxt: context to pass to operations 1110 * @def_link_id: id of the default link that will be automatically created by 1111 * the WWAN core for the WWAN device. The default link will not be created 1112 * if the passed value is WWAN_NO_DEFAULT_LINK. 1113 * 1114 * Returns: 0 on success, a negative error code on failure 1115 */ 1116 int wwan_register_ops(struct device *parent, const struct wwan_ops *ops, 1117 void *ctxt, u32 def_link_id) 1118 { 1119 struct wwan_device *wwandev; 1120 1121 if (WARN_ON(!parent || !ops || !ops->setup)) 1122 return -EINVAL; 1123 1124 wwandev = wwan_create_dev(parent); 1125 if (IS_ERR(wwandev)) 1126 return PTR_ERR(wwandev); 1127 1128 if (WARN_ON(wwandev->ops)) { 1129 wwan_remove_dev(wwandev); 1130 return -EBUSY; 1131 } 1132 1133 wwandev->ops = ops; 1134 wwandev->ops_ctxt = ctxt; 1135 1136 /* NB: we do not abort ops registration in case of default link 1137 * creation failure. Link ops is the management interface, while the 1138 * default link creation is a service option. And we should not prevent 1139 * a user from manually creating a link latter if service option failed 1140 * now. 1141 */ 1142 if (def_link_id != WWAN_NO_DEFAULT_LINK) 1143 wwan_create_default_link(wwandev, def_link_id); 1144 1145 return 0; 1146 } 1147 EXPORT_SYMBOL_GPL(wwan_register_ops); 1148 1149 /* Enqueue child netdev deletion */ 1150 static int wwan_child_dellink(struct device *dev, void *data) 1151 { 1152 struct list_head *kill_list = data; 1153 1154 if (dev->type == &wwan_type) 1155 wwan_rtnl_dellink(to_net_dev(dev), kill_list); 1156 1157 return 0; 1158 } 1159 1160 /** 1161 * wwan_unregister_ops - remove WWAN device ops 1162 * @parent: Device to use as parent and shared by all WWAN ports and 1163 * created netdevs 1164 */ 1165 void wwan_unregister_ops(struct device *parent) 1166 { 1167 struct wwan_device *wwandev = wwan_dev_get_by_parent(parent); 1168 LIST_HEAD(kill_list); 1169 1170 if (WARN_ON(IS_ERR(wwandev))) 1171 return; 1172 if (WARN_ON(!wwandev->ops)) { 1173 put_device(&wwandev->dev); 1174 return; 1175 } 1176 1177 /* put the reference obtained by wwan_dev_get_by_parent(), 1178 * we should still have one (that the owner is giving back 1179 * now) due to the ops being assigned. 1180 */ 1181 put_device(&wwandev->dev); 1182 1183 rtnl_lock(); /* Prevent concurent netdev(s) creation/destroying */ 1184 1185 /* Remove all child netdev(s), using batch removing */ 1186 device_for_each_child(&wwandev->dev, &kill_list, 1187 wwan_child_dellink); 1188 unregister_netdevice_many(&kill_list); 1189 1190 wwandev->ops = NULL; /* Finally remove ops */ 1191 1192 rtnl_unlock(); 1193 1194 wwandev->ops_ctxt = NULL; 1195 wwan_remove_dev(wwandev); 1196 } 1197 EXPORT_SYMBOL_GPL(wwan_unregister_ops); 1198 1199 static int __init wwan_init(void) 1200 { 1201 int err; 1202 1203 err = rtnl_link_register(&wwan_rtnl_link_ops); 1204 if (err) 1205 return err; 1206 1207 wwan_class = class_create(THIS_MODULE, "wwan"); 1208 if (IS_ERR(wwan_class)) { 1209 err = PTR_ERR(wwan_class); 1210 goto unregister; 1211 } 1212 1213 /* chrdev used for wwan ports */ 1214 wwan_major = __register_chrdev(0, 0, WWAN_MAX_MINORS, "wwan_port", 1215 &wwan_port_fops); 1216 if (wwan_major < 0) { 1217 err = wwan_major; 1218 goto destroy; 1219 } 1220 1221 #ifdef CONFIG_WWAN_DEBUGFS 1222 wwan_debugfs_dir = debugfs_create_dir("wwan", NULL); 1223 #endif 1224 1225 return 0; 1226 1227 destroy: 1228 class_destroy(wwan_class); 1229 unregister: 1230 rtnl_link_unregister(&wwan_rtnl_link_ops); 1231 return err; 1232 } 1233 1234 static void __exit wwan_exit(void) 1235 { 1236 debugfs_remove_recursive(wwan_debugfs_dir); 1237 __unregister_chrdev(wwan_major, 0, WWAN_MAX_MINORS, "wwan_port"); 1238 rtnl_link_unregister(&wwan_rtnl_link_ops); 1239 class_destroy(wwan_class); 1240 } 1241 1242 module_init(wwan_init); 1243 module_exit(wwan_exit); 1244 1245 MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>"); 1246 MODULE_DESCRIPTION("WWAN core"); 1247 MODULE_LICENSE("GPL v2"); 1248