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1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright (c) 2021, Linaro Ltd <loic.poulain@linaro.org> */
3
4#include <linux/bitmap.h>
5#include <linux/err.h>
6#include <linux/errno.h>
7#include <linux/debugfs.h>
8#include <linux/fs.h>
9#include <linux/init.h>
10#include <linux/idr.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/poll.h>
14#include <linux/skbuff.h>
15#include <linux/slab.h>
16#include <linux/types.h>
17#include <linux/uaccess.h>
18#include <linux/termios.h>
19#include <linux/wwan.h>
20#include <net/rtnetlink.h>
21#include <uapi/linux/wwan.h>
22
23/* Maximum number of minors in use */
24#define WWAN_MAX_MINORS (1 << MINORBITS)
25
26static DEFINE_MUTEX(wwan_register_lock); /* WWAN device create|remove lock */
27static DEFINE_IDA(minors); /* minors for WWAN port chardevs */
28static DEFINE_IDA(wwan_dev_ids); /* for unique WWAN device IDs */
29static const struct class wwan_class = {
30 .name = "wwan",
31};
32static int wwan_major;
33static struct dentry *wwan_debugfs_dir;
34
35#define to_wwan_dev(d) container_of(d, struct wwan_device, dev)
36#define to_wwan_port(d) container_of(d, struct wwan_port, dev)
37
38/* WWAN port flags */
39#define WWAN_PORT_TX_OFF 0
40
41/**
42 * struct wwan_device - The structure that defines a WWAN device
43 *
44 * @id: WWAN device unique ID.
45 * @dev: Underlying device.
46 * @port_id: Current available port ID to pick.
47 * @ops: wwan device ops
48 * @ops_ctxt: context to pass to ops
49 * @debugfs_dir: WWAN device debugfs dir
50 */
51struct wwan_device {
52 unsigned int id;
53 struct device dev;
54 atomic_t port_id;
55 const struct wwan_ops *ops;
56 void *ops_ctxt;
57#ifdef CONFIG_WWAN_DEBUGFS
58 struct dentry *debugfs_dir;
59#endif
60};
61
62/**
63 * struct wwan_port - The structure that defines a WWAN port
64 * @type: Port type
65 * @start_count: Port start counter
66 * @flags: Store port state and capabilities
67 * @ops: Pointer to WWAN port operations
68 * @ops_lock: Protect port ops
69 * @dev: Underlying device
70 * @rxq: Buffer inbound queue
71 * @waitqueue: The waitqueue for port fops (read/write/poll)
72 * @data_lock: Port specific data access serialization
73 * @headroom_len: SKB reserved headroom size
74 * @frag_len: Length to fragment packet
75 * @at_data: AT port specific data
76 */
77struct wwan_port {
78 enum wwan_port_type type;
79 unsigned int start_count;
80 unsigned long flags;
81 const struct wwan_port_ops *ops;
82 struct mutex ops_lock; /* Serialize ops + protect against removal */
83 struct device dev;
84 struct sk_buff_head rxq;
85 wait_queue_head_t waitqueue;
86 struct mutex data_lock; /* Port specific data access serialization */
87 size_t headroom_len;
88 size_t frag_len;
89 union {
90 struct {
91 struct ktermios termios;
92 int mdmbits;
93 } at_data;
94 };
95};
96
97static ssize_t index_show(struct device *dev, struct device_attribute *attr, char *buf)
98{
99 struct wwan_device *wwan = to_wwan_dev(dev);
100
101 return sprintf(buf, "%d\n", wwan->id);
102}
103static DEVICE_ATTR_RO(index);
104
105static struct attribute *wwan_dev_attrs[] = {
106 &dev_attr_index.attr,
107 NULL,
108};
109ATTRIBUTE_GROUPS(wwan_dev);
110
111static void wwan_dev_destroy(struct device *dev)
112{
113 struct wwan_device *wwandev = to_wwan_dev(dev);
114
115 ida_free(&wwan_dev_ids, wwandev->id);
116 kfree(wwandev);
117}
118
119static const struct device_type wwan_dev_type = {
120 .name = "wwan_dev",
121 .release = wwan_dev_destroy,
122 .groups = wwan_dev_groups,
123};
124
125static int wwan_dev_parent_match(struct device *dev, const void *parent)
126{
127 return (dev->type == &wwan_dev_type &&
128 (dev->parent == parent || dev == parent));
129}
130
131static struct wwan_device *wwan_dev_get_by_parent(struct device *parent)
132{
133 struct device *dev;
134
135 dev = class_find_device(&wwan_class, NULL, parent, wwan_dev_parent_match);
136 if (!dev)
137 return ERR_PTR(-ENODEV);
138
139 return to_wwan_dev(dev);
140}
141
142static int wwan_dev_name_match(struct device *dev, const void *name)
143{
144 return dev->type == &wwan_dev_type &&
145 strcmp(dev_name(dev), name) == 0;
146}
147
148static struct wwan_device *wwan_dev_get_by_name(const char *name)
149{
150 struct device *dev;
151
152 dev = class_find_device(&wwan_class, NULL, name, wwan_dev_name_match);
153 if (!dev)
154 return ERR_PTR(-ENODEV);
155
156 return to_wwan_dev(dev);
157}
158
159#ifdef CONFIG_WWAN_DEBUGFS
160struct dentry *wwan_get_debugfs_dir(struct device *parent)
161{
162 struct wwan_device *wwandev;
163
164 wwandev = wwan_dev_get_by_parent(parent);
165 if (IS_ERR(wwandev))
166 return ERR_CAST(wwandev);
167
168 return wwandev->debugfs_dir;
169}
170EXPORT_SYMBOL_GPL(wwan_get_debugfs_dir);
171
172static int wwan_dev_debugfs_match(struct device *dev, const void *dir)
173{
174 struct wwan_device *wwandev;
175
176 if (dev->type != &wwan_dev_type)
177 return 0;
178
179 wwandev = to_wwan_dev(dev);
180
181 return wwandev->debugfs_dir == dir;
182}
183
184static struct wwan_device *wwan_dev_get_by_debugfs(struct dentry *dir)
185{
186 struct device *dev;
187
188 dev = class_find_device(&wwan_class, NULL, dir, wwan_dev_debugfs_match);
189 if (!dev)
190 return ERR_PTR(-ENODEV);
191
192 return to_wwan_dev(dev);
193}
194
195void wwan_put_debugfs_dir(struct dentry *dir)
196{
197 struct wwan_device *wwandev = wwan_dev_get_by_debugfs(dir);
198
199 if (WARN_ON(IS_ERR(wwandev)))
200 return;
201
202 /* wwan_dev_get_by_debugfs() also got a reference */
203 put_device(&wwandev->dev);
204 put_device(&wwandev->dev);
205}
206EXPORT_SYMBOL_GPL(wwan_put_debugfs_dir);
207#endif
208
209/* This function allocates and registers a new WWAN device OR if a WWAN device
210 * already exist for the given parent, it gets a reference and return it.
211 * This function is not exported (for now), it is called indirectly via
212 * wwan_create_port().
213 */
214static struct wwan_device *wwan_create_dev(struct device *parent)
215{
216 struct wwan_device *wwandev;
217 int err, id;
218
219 /* The 'find-alloc-register' operation must be protected against
220 * concurrent execution, a WWAN device is possibly shared between
221 * multiple callers or concurrently unregistered from wwan_remove_dev().
222 */
223 mutex_lock(&wwan_register_lock);
224
225 /* If wwandev already exists, return it */
226 wwandev = wwan_dev_get_by_parent(parent);
227 if (!IS_ERR(wwandev))
228 goto done_unlock;
229
230 id = ida_alloc(&wwan_dev_ids, GFP_KERNEL);
231 if (id < 0) {
232 wwandev = ERR_PTR(id);
233 goto done_unlock;
234 }
235
236 wwandev = kzalloc(sizeof(*wwandev), GFP_KERNEL);
237 if (!wwandev) {
238 wwandev = ERR_PTR(-ENOMEM);
239 ida_free(&wwan_dev_ids, id);
240 goto done_unlock;
241 }
242
243 wwandev->dev.parent = parent;
244 wwandev->dev.class = &wwan_class;
245 wwandev->dev.type = &wwan_dev_type;
246 wwandev->id = id;
247 dev_set_name(&wwandev->dev, "wwan%d", wwandev->id);
248
249 err = device_register(&wwandev->dev);
250 if (err) {
251 put_device(&wwandev->dev);
252 wwandev = ERR_PTR(err);
253 goto done_unlock;
254 }
255
256#ifdef CONFIG_WWAN_DEBUGFS
257 wwandev->debugfs_dir =
258 debugfs_create_dir(kobject_name(&wwandev->dev.kobj),
259 wwan_debugfs_dir);
260#endif
261
262done_unlock:
263 mutex_unlock(&wwan_register_lock);
264
265 return wwandev;
266}
267
268static int is_wwan_child(struct device *dev, void *data)
269{
270 return dev->class == &wwan_class;
271}
272
273static void wwan_remove_dev(struct wwan_device *wwandev)
274{
275 int ret;
276
277 /* Prevent concurrent picking from wwan_create_dev */
278 mutex_lock(&wwan_register_lock);
279
280 /* WWAN device is created and registered (get+add) along with its first
281 * child port, and subsequent port registrations only grab a reference
282 * (get). The WWAN device must then be unregistered (del+put) along with
283 * its last port, and reference simply dropped (put) otherwise. In the
284 * same fashion, we must not unregister it when the ops are still there.
285 */
286 if (wwandev->ops)
287 ret = 1;
288 else
289 ret = device_for_each_child(&wwandev->dev, NULL, is_wwan_child);
290
291 if (!ret) {
292#ifdef CONFIG_WWAN_DEBUGFS
293 debugfs_remove_recursive(wwandev->debugfs_dir);
294#endif
295 device_unregister(&wwandev->dev);
296 } else {
297 put_device(&wwandev->dev);
298 }
299
300 mutex_unlock(&wwan_register_lock);
301}
302
303/* ------- WWAN port management ------- */
304
305static const struct {
306 const char * const name; /* Port type name */
307 const char * const devsuf; /* Port device name suffix */
308} wwan_port_types[WWAN_PORT_MAX + 1] = {
309 [WWAN_PORT_AT] = {
310 .name = "AT",
311 .devsuf = "at",
312 },
313 [WWAN_PORT_MBIM] = {
314 .name = "MBIM",
315 .devsuf = "mbim",
316 },
317 [WWAN_PORT_QMI] = {
318 .name = "QMI",
319 .devsuf = "qmi",
320 },
321 [WWAN_PORT_QCDM] = {
322 .name = "QCDM",
323 .devsuf = "qcdm",
324 },
325 [WWAN_PORT_FIREHOSE] = {
326 .name = "FIREHOSE",
327 .devsuf = "firehose",
328 },
329 [WWAN_PORT_XMMRPC] = {
330 .name = "XMMRPC",
331 .devsuf = "xmmrpc",
332 },
333 [WWAN_PORT_FASTBOOT] = {
334 .name = "FASTBOOT",
335 .devsuf = "fastboot",
336 },
337 [WWAN_PORT_ADB] = {
338 .name = "ADB",
339 .devsuf = "adb",
340 },
341 [WWAN_PORT_MIPC] = {
342 .name = "MIPC",
343 .devsuf = "mipc",
344 },
345};
346
347static ssize_t type_show(struct device *dev, struct device_attribute *attr,
348 char *buf)
349{
350 struct wwan_port *port = to_wwan_port(dev);
351
352 return sprintf(buf, "%s\n", wwan_port_types[port->type].name);
353}
354static DEVICE_ATTR_RO(type);
355
356static struct attribute *wwan_port_attrs[] = {
357 &dev_attr_type.attr,
358 NULL,
359};
360ATTRIBUTE_GROUPS(wwan_port);
361
362static void wwan_port_destroy(struct device *dev)
363{
364 struct wwan_port *port = to_wwan_port(dev);
365
366 ida_free(&minors, MINOR(port->dev.devt));
367 mutex_destroy(&port->data_lock);
368 mutex_destroy(&port->ops_lock);
369 kfree(port);
370}
371
372static const struct device_type wwan_port_dev_type = {
373 .name = "wwan_port",
374 .release = wwan_port_destroy,
375 .groups = wwan_port_groups,
376};
377
378static int wwan_port_minor_match(struct device *dev, const void *minor)
379{
380 return (dev->type == &wwan_port_dev_type &&
381 MINOR(dev->devt) == *(unsigned int *)minor);
382}
383
384static struct wwan_port *wwan_port_get_by_minor(unsigned int minor)
385{
386 struct device *dev;
387
388 dev = class_find_device(&wwan_class, NULL, &minor, wwan_port_minor_match);
389 if (!dev)
390 return ERR_PTR(-ENODEV);
391
392 return to_wwan_port(dev);
393}
394
395/* Allocate and set unique name based on passed format
396 *
397 * Name allocation approach is highly inspired by the __dev_alloc_name()
398 * function.
399 *
400 * To avoid names collision, the caller must prevent the new port device
401 * registration as well as concurrent invocation of this function.
402 */
403static int __wwan_port_dev_assign_name(struct wwan_port *port, const char *fmt)
404{
405 struct wwan_device *wwandev = to_wwan_dev(port->dev.parent);
406 const unsigned int max_ports = PAGE_SIZE * 8;
407 struct class_dev_iter iter;
408 unsigned long *idmap;
409 struct device *dev;
410 char buf[0x20];
411 int id;
412
413 idmap = bitmap_zalloc(max_ports, GFP_KERNEL);
414 if (!idmap)
415 return -ENOMEM;
416
417 /* Collect ids of same name format ports */
418 class_dev_iter_init(&iter, &wwan_class, NULL, &wwan_port_dev_type);
419 while ((dev = class_dev_iter_next(&iter))) {
420 if (dev->parent != &wwandev->dev)
421 continue;
422 if (sscanf(dev_name(dev), fmt, &id) != 1)
423 continue;
424 if (id < 0 || id >= max_ports)
425 continue;
426 set_bit(id, idmap);
427 }
428 class_dev_iter_exit(&iter);
429
430 /* Allocate unique id */
431 id = find_first_zero_bit(idmap, max_ports);
432 bitmap_free(idmap);
433
434 snprintf(buf, sizeof(buf), fmt, id); /* Name generation */
435
436 dev = device_find_child_by_name(&wwandev->dev, buf);
437 if (dev) {
438 put_device(dev);
439 return -ENFILE;
440 }
441
442 return dev_set_name(&port->dev, "%s", buf);
443}
444
445struct wwan_port *wwan_create_port(struct device *parent,
446 enum wwan_port_type type,
447 const struct wwan_port_ops *ops,
448 struct wwan_port_caps *caps,
449 void *drvdata)
450{
451 struct wwan_device *wwandev;
452 struct wwan_port *port;
453 char namefmt[0x20];
454 int minor, err;
455
456 if (type > WWAN_PORT_MAX || !ops)
457 return ERR_PTR(-EINVAL);
458
459 /* A port is always a child of a WWAN device, retrieve (allocate or
460 * pick) the WWAN device based on the provided parent device.
461 */
462 wwandev = wwan_create_dev(parent);
463 if (IS_ERR(wwandev))
464 return ERR_CAST(wwandev);
465
466 /* A port is exposed as character device, get a minor */
467 minor = ida_alloc_range(&minors, 0, WWAN_MAX_MINORS - 1, GFP_KERNEL);
468 if (minor < 0) {
469 err = minor;
470 goto error_wwandev_remove;
471 }
472
473 port = kzalloc(sizeof(*port), GFP_KERNEL);
474 if (!port) {
475 err = -ENOMEM;
476 ida_free(&minors, minor);
477 goto error_wwandev_remove;
478 }
479
480 port->type = type;
481 port->ops = ops;
482 port->frag_len = caps ? caps->frag_len : SIZE_MAX;
483 port->headroom_len = caps ? caps->headroom_len : 0;
484 mutex_init(&port->ops_lock);
485 skb_queue_head_init(&port->rxq);
486 init_waitqueue_head(&port->waitqueue);
487 mutex_init(&port->data_lock);
488
489 port->dev.parent = &wwandev->dev;
490 port->dev.class = &wwan_class;
491 port->dev.type = &wwan_port_dev_type;
492 port->dev.devt = MKDEV(wwan_major, minor);
493 dev_set_drvdata(&port->dev, drvdata);
494
495 /* allocate unique name based on wwan device id, port type and number */
496 snprintf(namefmt, sizeof(namefmt), "wwan%u%s%%d", wwandev->id,
497 wwan_port_types[port->type].devsuf);
498
499 /* Serialize ports registration */
500 mutex_lock(&wwan_register_lock);
501
502 __wwan_port_dev_assign_name(port, namefmt);
503 err = device_register(&port->dev);
504
505 mutex_unlock(&wwan_register_lock);
506
507 if (err)
508 goto error_put_device;
509
510 dev_info(&wwandev->dev, "port %s attached\n", dev_name(&port->dev));
511 return port;
512
513error_put_device:
514 put_device(&port->dev);
515error_wwandev_remove:
516 wwan_remove_dev(wwandev);
517
518 return ERR_PTR(err);
519}
520EXPORT_SYMBOL_GPL(wwan_create_port);
521
522void wwan_remove_port(struct wwan_port *port)
523{
524 struct wwan_device *wwandev = to_wwan_dev(port->dev.parent);
525
526 mutex_lock(&port->ops_lock);
527 if (port->start_count)
528 port->ops->stop(port);
529 port->ops = NULL; /* Prevent any new port operations (e.g. from fops) */
530 mutex_unlock(&port->ops_lock);
531
532 wake_up_interruptible(&port->waitqueue);
533
534 skb_queue_purge(&port->rxq);
535 dev_set_drvdata(&port->dev, NULL);
536
537 dev_info(&wwandev->dev, "port %s disconnected\n", dev_name(&port->dev));
538 device_unregister(&port->dev);
539
540 /* Release related wwan device */
541 wwan_remove_dev(wwandev);
542}
543EXPORT_SYMBOL_GPL(wwan_remove_port);
544
545void wwan_port_rx(struct wwan_port *port, struct sk_buff *skb)
546{
547 skb_queue_tail(&port->rxq, skb);
548 wake_up_interruptible(&port->waitqueue);
549}
550EXPORT_SYMBOL_GPL(wwan_port_rx);
551
552void wwan_port_txon(struct wwan_port *port)
553{
554 clear_bit(WWAN_PORT_TX_OFF, &port->flags);
555 wake_up_interruptible(&port->waitqueue);
556}
557EXPORT_SYMBOL_GPL(wwan_port_txon);
558
559void wwan_port_txoff(struct wwan_port *port)
560{
561 set_bit(WWAN_PORT_TX_OFF, &port->flags);
562}
563EXPORT_SYMBOL_GPL(wwan_port_txoff);
564
565void *wwan_port_get_drvdata(struct wwan_port *port)
566{
567 return dev_get_drvdata(&port->dev);
568}
569EXPORT_SYMBOL_GPL(wwan_port_get_drvdata);
570
571static int wwan_port_op_start(struct wwan_port *port)
572{
573 int ret = 0;
574
575 mutex_lock(&port->ops_lock);
576 if (!port->ops) { /* Port got unplugged */
577 ret = -ENODEV;
578 goto out_unlock;
579 }
580
581 /* If port is already started, don't start again */
582 if (!port->start_count)
583 ret = port->ops->start(port);
584
585 if (!ret)
586 port->start_count++;
587
588out_unlock:
589 mutex_unlock(&port->ops_lock);
590
591 return ret;
592}
593
594static void wwan_port_op_stop(struct wwan_port *port)
595{
596 mutex_lock(&port->ops_lock);
597 port->start_count--;
598 if (!port->start_count) {
599 if (port->ops)
600 port->ops->stop(port);
601 skb_queue_purge(&port->rxq);
602 }
603 mutex_unlock(&port->ops_lock);
604}
605
606static int wwan_port_op_tx(struct wwan_port *port, struct sk_buff *skb,
607 bool nonblock)
608{
609 int ret;
610
611 mutex_lock(&port->ops_lock);
612 if (!port->ops) { /* Port got unplugged */
613 ret = -ENODEV;
614 goto out_unlock;
615 }
616
617 if (nonblock || !port->ops->tx_blocking)
618 ret = port->ops->tx(port, skb);
619 else
620 ret = port->ops->tx_blocking(port, skb);
621
622out_unlock:
623 mutex_unlock(&port->ops_lock);
624
625 return ret;
626}
627
628static bool is_read_blocked(struct wwan_port *port)
629{
630 return skb_queue_empty(&port->rxq) && port->ops;
631}
632
633static bool is_write_blocked(struct wwan_port *port)
634{
635 return test_bit(WWAN_PORT_TX_OFF, &port->flags) && port->ops;
636}
637
638static int wwan_wait_rx(struct wwan_port *port, bool nonblock)
639{
640 if (!is_read_blocked(port))
641 return 0;
642
643 if (nonblock)
644 return -EAGAIN;
645
646 if (wait_event_interruptible(port->waitqueue, !is_read_blocked(port)))
647 return -ERESTARTSYS;
648
649 return 0;
650}
651
652static int wwan_wait_tx(struct wwan_port *port, bool nonblock)
653{
654 if (!is_write_blocked(port))
655 return 0;
656
657 if (nonblock)
658 return -EAGAIN;
659
660 if (wait_event_interruptible(port->waitqueue, !is_write_blocked(port)))
661 return -ERESTARTSYS;
662
663 return 0;
664}
665
666static int wwan_port_fops_open(struct inode *inode, struct file *file)
667{
668 struct wwan_port *port;
669 int err = 0;
670
671 port = wwan_port_get_by_minor(iminor(inode));
672 if (IS_ERR(port))
673 return PTR_ERR(port);
674
675 file->private_data = port;
676 stream_open(inode, file);
677
678 err = wwan_port_op_start(port);
679 if (err)
680 put_device(&port->dev);
681
682 return err;
683}
684
685static int wwan_port_fops_release(struct inode *inode, struct file *filp)
686{
687 struct wwan_port *port = filp->private_data;
688
689 wwan_port_op_stop(port);
690 put_device(&port->dev);
691
692 return 0;
693}
694
695static ssize_t wwan_port_fops_read(struct file *filp, char __user *buf,
696 size_t count, loff_t *ppos)
697{
698 struct wwan_port *port = filp->private_data;
699 struct sk_buff *skb;
700 size_t copied;
701 int ret;
702
703 ret = wwan_wait_rx(port, !!(filp->f_flags & O_NONBLOCK));
704 if (ret)
705 return ret;
706
707 skb = skb_dequeue(&port->rxq);
708 if (!skb)
709 return -EIO;
710
711 copied = min_t(size_t, count, skb->len);
712 if (copy_to_user(buf, skb->data, copied)) {
713 kfree_skb(skb);
714 return -EFAULT;
715 }
716 skb_pull(skb, copied);
717
718 /* skb is not fully consumed, keep it in the queue */
719 if (skb->len)
720 skb_queue_head(&port->rxq, skb);
721 else
722 consume_skb(skb);
723
724 return copied;
725}
726
727static ssize_t wwan_port_fops_write(struct file *filp, const char __user *buf,
728 size_t count, loff_t *offp)
729{
730 struct sk_buff *skb, *head = NULL, *tail = NULL;
731 struct wwan_port *port = filp->private_data;
732 size_t frag_len, remain = count;
733 int ret;
734
735 ret = wwan_wait_tx(port, !!(filp->f_flags & O_NONBLOCK));
736 if (ret)
737 return ret;
738
739 do {
740 frag_len = min(remain, port->frag_len);
741 skb = alloc_skb(frag_len + port->headroom_len, GFP_KERNEL);
742 if (!skb) {
743 ret = -ENOMEM;
744 goto freeskb;
745 }
746 skb_reserve(skb, port->headroom_len);
747
748 if (!head) {
749 head = skb;
750 } else if (!tail) {
751 skb_shinfo(head)->frag_list = skb;
752 tail = skb;
753 } else {
754 tail->next = skb;
755 tail = skb;
756 }
757
758 if (copy_from_user(skb_put(skb, frag_len), buf + count - remain, frag_len)) {
759 ret = -EFAULT;
760 goto freeskb;
761 }
762
763 if (skb != head) {
764 head->data_len += skb->len;
765 head->len += skb->len;
766 head->truesize += skb->truesize;
767 }
768 } while (remain -= frag_len);
769
770 ret = wwan_port_op_tx(port, head, !!(filp->f_flags & O_NONBLOCK));
771 if (!ret)
772 return count;
773
774freeskb:
775 kfree_skb(head);
776 return ret;
777}
778
779static __poll_t wwan_port_fops_poll(struct file *filp, poll_table *wait)
780{
781 struct wwan_port *port = filp->private_data;
782 __poll_t mask = 0;
783
784 poll_wait(filp, &port->waitqueue, wait);
785
786 mutex_lock(&port->ops_lock);
787 if (port->ops && port->ops->tx_poll)
788 mask |= port->ops->tx_poll(port, filp, wait);
789 else if (!is_write_blocked(port))
790 mask |= EPOLLOUT | EPOLLWRNORM;
791 if (!is_read_blocked(port))
792 mask |= EPOLLIN | EPOLLRDNORM;
793 if (!port->ops)
794 mask |= EPOLLHUP | EPOLLERR;
795 mutex_unlock(&port->ops_lock);
796
797 return mask;
798}
799
800/* Implements minimalistic stub terminal IOCTLs support */
801static long wwan_port_fops_at_ioctl(struct wwan_port *port, unsigned int cmd,
802 unsigned long arg)
803{
804 int ret = 0;
805
806 mutex_lock(&port->data_lock);
807
808 switch (cmd) {
809 case TCFLSH:
810 break;
811
812 case TCGETS:
813 if (copy_to_user((void __user *)arg, &port->at_data.termios,
814 sizeof(struct termios)))
815 ret = -EFAULT;
816 break;
817
818 case TCSETS:
819 case TCSETSW:
820 case TCSETSF:
821 if (copy_from_user(&port->at_data.termios, (void __user *)arg,
822 sizeof(struct termios)))
823 ret = -EFAULT;
824 break;
825
826#ifdef TCGETS2
827 case TCGETS2:
828 if (copy_to_user((void __user *)arg, &port->at_data.termios,
829 sizeof(struct termios2)))
830 ret = -EFAULT;
831 break;
832
833 case TCSETS2:
834 case TCSETSW2:
835 case TCSETSF2:
836 if (copy_from_user(&port->at_data.termios, (void __user *)arg,
837 sizeof(struct termios2)))
838 ret = -EFAULT;
839 break;
840#endif
841
842 case TIOCMGET:
843 ret = put_user(port->at_data.mdmbits, (int __user *)arg);
844 break;
845
846 case TIOCMSET:
847 case TIOCMBIC:
848 case TIOCMBIS: {
849 int mdmbits;
850
851 if (copy_from_user(&mdmbits, (int __user *)arg, sizeof(int))) {
852 ret = -EFAULT;
853 break;
854 }
855 if (cmd == TIOCMBIC)
856 port->at_data.mdmbits &= ~mdmbits;
857 else if (cmd == TIOCMBIS)
858 port->at_data.mdmbits |= mdmbits;
859 else
860 port->at_data.mdmbits = mdmbits;
861 break;
862 }
863
864 default:
865 ret = -ENOIOCTLCMD;
866 }
867
868 mutex_unlock(&port->data_lock);
869
870 return ret;
871}
872
873static long wwan_port_fops_ioctl(struct file *filp, unsigned int cmd,
874 unsigned long arg)
875{
876 struct wwan_port *port = filp->private_data;
877 int res;
878
879 if (port->type == WWAN_PORT_AT) { /* AT port specific IOCTLs */
880 res = wwan_port_fops_at_ioctl(port, cmd, arg);
881 if (res != -ENOIOCTLCMD)
882 return res;
883 }
884
885 switch (cmd) {
886 case TIOCINQ: { /* aka SIOCINQ aka FIONREAD */
887 unsigned long flags;
888 struct sk_buff *skb;
889 int amount = 0;
890
891 spin_lock_irqsave(&port->rxq.lock, flags);
892 skb_queue_walk(&port->rxq, skb)
893 amount += skb->len;
894 spin_unlock_irqrestore(&port->rxq.lock, flags);
895
896 return put_user(amount, (int __user *)arg);
897 }
898
899 default:
900 return -ENOIOCTLCMD;
901 }
902}
903
904static const struct file_operations wwan_port_fops = {
905 .owner = THIS_MODULE,
906 .open = wwan_port_fops_open,
907 .release = wwan_port_fops_release,
908 .read = wwan_port_fops_read,
909 .write = wwan_port_fops_write,
910 .poll = wwan_port_fops_poll,
911 .unlocked_ioctl = wwan_port_fops_ioctl,
912#ifdef CONFIG_COMPAT
913 .compat_ioctl = compat_ptr_ioctl,
914#endif
915 .llseek = noop_llseek,
916};
917
918static int wwan_rtnl_validate(struct nlattr *tb[], struct nlattr *data[],
919 struct netlink_ext_ack *extack)
920{
921 if (!data)
922 return -EINVAL;
923
924 if (!tb[IFLA_PARENT_DEV_NAME])
925 return -EINVAL;
926
927 if (!data[IFLA_WWAN_LINK_ID])
928 return -EINVAL;
929
930 return 0;
931}
932
933static const struct device_type wwan_type = { .name = "wwan" };
934
935static struct net_device *wwan_rtnl_alloc(struct nlattr *tb[],
936 const char *ifname,
937 unsigned char name_assign_type,
938 unsigned int num_tx_queues,
939 unsigned int num_rx_queues)
940{
941 const char *devname = nla_data(tb[IFLA_PARENT_DEV_NAME]);
942 struct wwan_device *wwandev = wwan_dev_get_by_name(devname);
943 struct net_device *dev;
944 unsigned int priv_size;
945
946 if (IS_ERR(wwandev))
947 return ERR_CAST(wwandev);
948
949 /* only supported if ops were registered (not just ports) */
950 if (!wwandev->ops) {
951 dev = ERR_PTR(-EOPNOTSUPP);
952 goto out;
953 }
954
955 priv_size = sizeof(struct wwan_netdev_priv) + wwandev->ops->priv_size;
956 dev = alloc_netdev_mqs(priv_size, ifname, name_assign_type,
957 wwandev->ops->setup, num_tx_queues, num_rx_queues);
958
959 if (dev) {
960 SET_NETDEV_DEV(dev, &wwandev->dev);
961 SET_NETDEV_DEVTYPE(dev, &wwan_type);
962 }
963
964out:
965 /* release the reference */
966 put_device(&wwandev->dev);
967 return dev;
968}
969
970static int wwan_rtnl_newlink(struct net *src_net, struct net_device *dev,
971 struct nlattr *tb[], struct nlattr *data[],
972 struct netlink_ext_ack *extack)
973{
974 struct wwan_device *wwandev = wwan_dev_get_by_parent(dev->dev.parent);
975 u32 link_id = nla_get_u32(data[IFLA_WWAN_LINK_ID]);
976 struct wwan_netdev_priv *priv = netdev_priv(dev);
977 int ret;
978
979 if (IS_ERR(wwandev))
980 return PTR_ERR(wwandev);
981
982 /* shouldn't have a netdev (left) with us as parent so WARN */
983 if (WARN_ON(!wwandev->ops)) {
984 ret = -EOPNOTSUPP;
985 goto out;
986 }
987
988 priv->link_id = link_id;
989 if (wwandev->ops->newlink)
990 ret = wwandev->ops->newlink(wwandev->ops_ctxt, dev,
991 link_id, extack);
992 else
993 ret = register_netdevice(dev);
994
995out:
996 /* release the reference */
997 put_device(&wwandev->dev);
998 return ret;
999}
1000
1001static void wwan_rtnl_dellink(struct net_device *dev, struct list_head *head)
1002{
1003 struct wwan_device *wwandev = wwan_dev_get_by_parent(dev->dev.parent);
1004
1005 if (IS_ERR(wwandev))
1006 return;
1007
1008 /* shouldn't have a netdev (left) with us as parent so WARN */
1009 if (WARN_ON(!wwandev->ops))
1010 goto out;
1011
1012 if (wwandev->ops->dellink)
1013 wwandev->ops->dellink(wwandev->ops_ctxt, dev, head);
1014 else
1015 unregister_netdevice_queue(dev, head);
1016
1017out:
1018 /* release the reference */
1019 put_device(&wwandev->dev);
1020}
1021
1022static size_t wwan_rtnl_get_size(const struct net_device *dev)
1023{
1024 return
1025 nla_total_size(4) + /* IFLA_WWAN_LINK_ID */
1026 0;
1027}
1028
1029static int wwan_rtnl_fill_info(struct sk_buff *skb,
1030 const struct net_device *dev)
1031{
1032 struct wwan_netdev_priv *priv = netdev_priv(dev);
1033
1034 if (nla_put_u32(skb, IFLA_WWAN_LINK_ID, priv->link_id))
1035 goto nla_put_failure;
1036
1037 return 0;
1038
1039nla_put_failure:
1040 return -EMSGSIZE;
1041}
1042
1043static const struct nla_policy wwan_rtnl_policy[IFLA_WWAN_MAX + 1] = {
1044 [IFLA_WWAN_LINK_ID] = { .type = NLA_U32 },
1045};
1046
1047static struct rtnl_link_ops wwan_rtnl_link_ops __read_mostly = {
1048 .kind = "wwan",
1049 .maxtype = IFLA_WWAN_MAX,
1050 .alloc = wwan_rtnl_alloc,
1051 .validate = wwan_rtnl_validate,
1052 .newlink = wwan_rtnl_newlink,
1053 .dellink = wwan_rtnl_dellink,
1054 .get_size = wwan_rtnl_get_size,
1055 .fill_info = wwan_rtnl_fill_info,
1056 .policy = wwan_rtnl_policy,
1057};
1058
1059static void wwan_create_default_link(struct wwan_device *wwandev,
1060 u32 def_link_id)
1061{
1062 struct nlattr *tb[IFLA_MAX + 1], *linkinfo[IFLA_INFO_MAX + 1];
1063 struct nlattr *data[IFLA_WWAN_MAX + 1];
1064 struct net_device *dev;
1065 struct nlmsghdr *nlh;
1066 struct sk_buff *msg;
1067
1068 /* Forge attributes required to create a WWAN netdev. We first
1069 * build a netlink message and then parse it. This looks
1070 * odd, but such approach is less error prone.
1071 */
1072 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1073 if (WARN_ON(!msg))
1074 return;
1075 nlh = nlmsg_put(msg, 0, 0, RTM_NEWLINK, 0, 0);
1076 if (WARN_ON(!nlh))
1077 goto free_attrs;
1078
1079 if (nla_put_string(msg, IFLA_PARENT_DEV_NAME, dev_name(&wwandev->dev)))
1080 goto free_attrs;
1081 tb[IFLA_LINKINFO] = nla_nest_start(msg, IFLA_LINKINFO);
1082 if (!tb[IFLA_LINKINFO])
1083 goto free_attrs;
1084 linkinfo[IFLA_INFO_DATA] = nla_nest_start(msg, IFLA_INFO_DATA);
1085 if (!linkinfo[IFLA_INFO_DATA])
1086 goto free_attrs;
1087 if (nla_put_u32(msg, IFLA_WWAN_LINK_ID, def_link_id))
1088 goto free_attrs;
1089 nla_nest_end(msg, linkinfo[IFLA_INFO_DATA]);
1090 nla_nest_end(msg, tb[IFLA_LINKINFO]);
1091
1092 nlmsg_end(msg, nlh);
1093
1094 /* The next three parsing calls can not fail */
1095 nlmsg_parse_deprecated(nlh, 0, tb, IFLA_MAX, NULL, NULL);
1096 nla_parse_nested_deprecated(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO],
1097 NULL, NULL);
1098 nla_parse_nested_deprecated(data, IFLA_WWAN_MAX,
1099 linkinfo[IFLA_INFO_DATA], NULL, NULL);
1100
1101 rtnl_lock();
1102
1103 dev = rtnl_create_link(&init_net, "wwan%d", NET_NAME_ENUM,
1104 &wwan_rtnl_link_ops, tb, NULL);
1105 if (WARN_ON(IS_ERR(dev)))
1106 goto unlock;
1107
1108 if (WARN_ON(wwan_rtnl_newlink(&init_net, dev, tb, data, NULL))) {
1109 free_netdev(dev);
1110 goto unlock;
1111 }
1112
1113 rtnl_configure_link(dev, NULL, 0, NULL); /* Link initialized, notify new link */
1114
1115unlock:
1116 rtnl_unlock();
1117
1118free_attrs:
1119 nlmsg_free(msg);
1120}
1121
1122/**
1123 * wwan_register_ops - register WWAN device ops
1124 * @parent: Device to use as parent and shared by all WWAN ports and
1125 * created netdevs
1126 * @ops: operations to register
1127 * @ctxt: context to pass to operations
1128 * @def_link_id: id of the default link that will be automatically created by
1129 * the WWAN core for the WWAN device. The default link will not be created
1130 * if the passed value is WWAN_NO_DEFAULT_LINK.
1131 *
1132 * Returns: 0 on success, a negative error code on failure
1133 */
1134int wwan_register_ops(struct device *parent, const struct wwan_ops *ops,
1135 void *ctxt, u32 def_link_id)
1136{
1137 struct wwan_device *wwandev;
1138
1139 if (WARN_ON(!parent || !ops || !ops->setup))
1140 return -EINVAL;
1141
1142 wwandev = wwan_create_dev(parent);
1143 if (IS_ERR(wwandev))
1144 return PTR_ERR(wwandev);
1145
1146 if (WARN_ON(wwandev->ops)) {
1147 wwan_remove_dev(wwandev);
1148 return -EBUSY;
1149 }
1150
1151 wwandev->ops = ops;
1152 wwandev->ops_ctxt = ctxt;
1153
1154 /* NB: we do not abort ops registration in case of default link
1155 * creation failure. Link ops is the management interface, while the
1156 * default link creation is a service option. And we should not prevent
1157 * a user from manually creating a link latter if service option failed
1158 * now.
1159 */
1160 if (def_link_id != WWAN_NO_DEFAULT_LINK)
1161 wwan_create_default_link(wwandev, def_link_id);
1162
1163 return 0;
1164}
1165EXPORT_SYMBOL_GPL(wwan_register_ops);
1166
1167/* Enqueue child netdev deletion */
1168static int wwan_child_dellink(struct device *dev, void *data)
1169{
1170 struct list_head *kill_list = data;
1171
1172 if (dev->type == &wwan_type)
1173 wwan_rtnl_dellink(to_net_dev(dev), kill_list);
1174
1175 return 0;
1176}
1177
1178/**
1179 * wwan_unregister_ops - remove WWAN device ops
1180 * @parent: Device to use as parent and shared by all WWAN ports and
1181 * created netdevs
1182 */
1183void wwan_unregister_ops(struct device *parent)
1184{
1185 struct wwan_device *wwandev = wwan_dev_get_by_parent(parent);
1186 LIST_HEAD(kill_list);
1187
1188 if (WARN_ON(IS_ERR(wwandev)))
1189 return;
1190 if (WARN_ON(!wwandev->ops)) {
1191 put_device(&wwandev->dev);
1192 return;
1193 }
1194
1195 /* put the reference obtained by wwan_dev_get_by_parent(),
1196 * we should still have one (that the owner is giving back
1197 * now) due to the ops being assigned.
1198 */
1199 put_device(&wwandev->dev);
1200
1201 rtnl_lock(); /* Prevent concurrent netdev(s) creation/destroying */
1202
1203 /* Remove all child netdev(s), using batch removing */
1204 device_for_each_child(&wwandev->dev, &kill_list,
1205 wwan_child_dellink);
1206 unregister_netdevice_many(&kill_list);
1207
1208 wwandev->ops = NULL; /* Finally remove ops */
1209
1210 rtnl_unlock();
1211
1212 wwandev->ops_ctxt = NULL;
1213 wwan_remove_dev(wwandev);
1214}
1215EXPORT_SYMBOL_GPL(wwan_unregister_ops);
1216
1217static int __init wwan_init(void)
1218{
1219 int err;
1220
1221 err = rtnl_link_register(&wwan_rtnl_link_ops);
1222 if (err)
1223 return err;
1224
1225 err = class_register(&wwan_class);
1226 if (err)
1227 goto unregister;
1228
1229 /* chrdev used for wwan ports */
1230 wwan_major = __register_chrdev(0, 0, WWAN_MAX_MINORS, "wwan_port",
1231 &wwan_port_fops);
1232 if (wwan_major < 0) {
1233 err = wwan_major;
1234 goto destroy;
1235 }
1236
1237#ifdef CONFIG_WWAN_DEBUGFS
1238 wwan_debugfs_dir = debugfs_create_dir("wwan", NULL);
1239#endif
1240
1241 return 0;
1242
1243destroy:
1244 class_unregister(&wwan_class);
1245unregister:
1246 rtnl_link_unregister(&wwan_rtnl_link_ops);
1247 return err;
1248}
1249
1250static void __exit wwan_exit(void)
1251{
1252 debugfs_remove_recursive(wwan_debugfs_dir);
1253 __unregister_chrdev(wwan_major, 0, WWAN_MAX_MINORS, "wwan_port");
1254 rtnl_link_unregister(&wwan_rtnl_link_ops);
1255 class_unregister(&wwan_class);
1256}
1257
1258module_init(wwan_init);
1259module_exit(wwan_exit);
1260
1261MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>");
1262MODULE_DESCRIPTION("WWAN core");
1263MODULE_LICENSE("GPL v2");