Commit | Line | Data |
---|---|---|
e3b3d0f5 | 1 | // SPDX-License-Identifier: GPL-2.0 |
9e48565d AC |
2 | /* |
3 | * Tty port functions | |
4 | */ | |
5 | ||
6 | #include <linux/types.h> | |
7 | #include <linux/errno.h> | |
8 | #include <linux/tty.h> | |
9 | #include <linux/tty_driver.h> | |
10 | #include <linux/tty_flip.h> | |
3e61696b | 11 | #include <linux/serial.h> |
9e48565d AC |
12 | #include <linux/timer.h> |
13 | #include <linux/string.h> | |
14 | #include <linux/slab.h> | |
174cd4b1 | 15 | #include <linux/sched/signal.h> |
9e48565d AC |
16 | #include <linux/wait.h> |
17 | #include <linux/bitops.h> | |
18 | #include <linux/delay.h> | |
19 | #include <linux/module.h> | |
8cde11b2 | 20 | #include <linux/serdev.h> |
98602c01 | 21 | #include "tty.h" |
9e48565d | 22 | |
c3485ee0 RH |
23 | static int tty_port_default_receive_buf(struct tty_port *port, |
24 | const unsigned char *p, | |
25 | const unsigned char *f, size_t count) | |
26 | { | |
27 | int ret; | |
28 | struct tty_struct *tty; | |
29 | struct tty_ldisc *disc; | |
30 | ||
31 | tty = READ_ONCE(port->itty); | |
32 | if (!tty) | |
33 | return 0; | |
34 | ||
35 | disc = tty_ldisc_ref(tty); | |
36 | if (!disc) | |
37 | return 0; | |
38 | ||
39 | ret = tty_ldisc_receive_buf(disc, p, (char *)f, count); | |
40 | ||
41 | tty_ldisc_deref(disc); | |
42 | ||
43 | return ret; | |
44 | } | |
45 | ||
46 | static void tty_port_default_wakeup(struct tty_port *port) | |
47 | { | |
48 | struct tty_struct *tty = tty_port_tty_get(port); | |
49 | ||
50 | if (tty) { | |
51 | tty_wakeup(tty); | |
52 | tty_kref_put(tty); | |
53 | } | |
54 | } | |
55 | ||
0c5aae59 | 56 | const struct tty_port_client_operations tty_port_default_client_ops = { |
c3485ee0 RH |
57 | .receive_buf = tty_port_default_receive_buf, |
58 | .write_wakeup = tty_port_default_wakeup, | |
59 | }; | |
0c5aae59 | 60 | EXPORT_SYMBOL_GPL(tty_port_default_client_ops); |
c3485ee0 | 61 | |
9e48565d AC |
62 | void tty_port_init(struct tty_port *port) |
63 | { | |
64 | memset(port, 0, sizeof(*port)); | |
ecbbfd44 | 65 | tty_buffer_init(port); |
9e48565d | 66 | init_waitqueue_head(&port->open_wait); |
bdc04e31 | 67 | init_waitqueue_head(&port->delta_msr_wait); |
9e48565d | 68 | mutex_init(&port->mutex); |
44e4909e | 69 | mutex_init(&port->buf_mutex); |
4a90f09b | 70 | spin_lock_init(&port->lock); |
9e48565d AC |
71 | port->close_delay = (50 * HZ) / 100; |
72 | port->closing_wait = (3000 * HZ) / 100; | |
0c5aae59 | 73 | port->client_ops = &tty_port_default_client_ops; |
568aafc6 | 74 | kref_init(&port->kref); |
9e48565d AC |
75 | } |
76 | EXPORT_SYMBOL(tty_port_init); | |
77 | ||
2cb4ca02 JS |
78 | /** |
79 | * tty_port_link_device - link tty and tty_port | |
80 | * @port: tty_port of the device | |
81 | * @driver: tty_driver for this device | |
82 | * @index: index of the tty | |
83 | * | |
1926e5d3 | 84 | * Provide the tty layer with a link from a tty (specified by @index) to a |
2cb4ca02 JS |
85 | * tty_port (@port). Use this only if neither tty_port_register_device nor |
86 | * tty_port_install is used in the driver. If used, this has to be called before | |
87 | * tty_register_driver. | |
88 | */ | |
89 | void tty_port_link_device(struct tty_port *port, | |
90 | struct tty_driver *driver, unsigned index) | |
91 | { | |
92 | if (WARN_ON(index >= driver->num)) | |
93 | return; | |
273f6329 | 94 | driver->ports[index] = port; |
2cb4ca02 JS |
95 | } |
96 | EXPORT_SYMBOL_GPL(tty_port_link_device); | |
97 | ||
72a33bf5 JS |
98 | /** |
99 | * tty_port_register_device - register tty device | |
100 | * @port: tty_port of the device | |
101 | * @driver: tty_driver for this device | |
102 | * @index: index of the tty | |
103 | * @device: parent if exists, otherwise NULL | |
104 | * | |
105 | * It is the same as tty_register_device except the provided @port is linked to | |
106 | * a concrete tty specified by @index. Use this or tty_port_install (or both). | |
107 | * Call tty_port_link_device as a last resort. | |
108 | */ | |
057eb856 JS |
109 | struct device *tty_port_register_device(struct tty_port *port, |
110 | struct tty_driver *driver, unsigned index, | |
111 | struct device *device) | |
112 | { | |
3086365d | 113 | return tty_port_register_device_attr(port, driver, index, device, NULL, NULL); |
057eb856 JS |
114 | } |
115 | EXPORT_SYMBOL_GPL(tty_port_register_device); | |
116 | ||
b1b79916 TH |
117 | /** |
118 | * tty_port_register_device_attr - register tty device | |
119 | * @port: tty_port of the device | |
120 | * @driver: tty_driver for this device | |
121 | * @index: index of the tty | |
122 | * @device: parent if exists, otherwise NULL | |
123 | * @drvdata: Driver data to be set to device. | |
124 | * @attr_grp: Attribute group to be set on device. | |
125 | * | |
126 | * It is the same as tty_register_device_attr except the provided @port is | |
127 | * linked to a concrete tty specified by @index. Use this or tty_port_install | |
128 | * (or both). Call tty_port_link_device as a last resort. | |
129 | */ | |
130 | struct device *tty_port_register_device_attr(struct tty_port *port, | |
131 | struct tty_driver *driver, unsigned index, | |
132 | struct device *device, void *drvdata, | |
133 | const struct attribute_group **attr_grp) | |
134 | { | |
135 | tty_port_link_device(port, driver, index); | |
136 | return tty_register_device_attr(driver, index, device, drvdata, | |
137 | attr_grp); | |
138 | } | |
139 | EXPORT_SYMBOL_GPL(tty_port_register_device_attr); | |
140 | ||
8cde11b2 JH |
141 | /** |
142 | * tty_port_register_device_attr_serdev - register tty or serdev device | |
143 | * @port: tty_port of the device | |
144 | * @driver: tty_driver for this device | |
145 | * @index: index of the tty | |
146 | * @device: parent if exists, otherwise NULL | |
147 | * @drvdata: driver data for the device | |
148 | * @attr_grp: attribute group for the device | |
149 | * | |
150 | * Register a serdev or tty device depending on if the parent device has any | |
151 | * defined serdev clients or not. | |
152 | */ | |
153 | struct device *tty_port_register_device_attr_serdev(struct tty_port *port, | |
154 | struct tty_driver *driver, unsigned index, | |
155 | struct device *device, void *drvdata, | |
156 | const struct attribute_group **attr_grp) | |
157 | { | |
158 | struct device *dev; | |
159 | ||
160 | tty_port_link_device(port, driver, index); | |
161 | ||
162 | dev = serdev_tty_port_register(port, device, driver, index); | |
163 | if (PTR_ERR(dev) != -ENODEV) { | |
164 | /* Skip creating cdev if we registered a serdev device */ | |
165 | return dev; | |
166 | } | |
167 | ||
168 | return tty_register_device_attr(driver, index, device, drvdata, | |
169 | attr_grp); | |
170 | } | |
171 | EXPORT_SYMBOL_GPL(tty_port_register_device_attr_serdev); | |
172 | ||
173 | /** | |
174 | * tty_port_register_device_serdev - register tty or serdev device | |
175 | * @port: tty_port of the device | |
176 | * @driver: tty_driver for this device | |
177 | * @index: index of the tty | |
178 | * @device: parent if exists, otherwise NULL | |
179 | * | |
180 | * Register a serdev or tty device depending on if the parent device has any | |
181 | * defined serdev clients or not. | |
182 | */ | |
183 | struct device *tty_port_register_device_serdev(struct tty_port *port, | |
184 | struct tty_driver *driver, unsigned index, | |
185 | struct device *device) | |
186 | { | |
187 | return tty_port_register_device_attr_serdev(port, driver, index, | |
188 | device, NULL, NULL); | |
189 | } | |
190 | EXPORT_SYMBOL_GPL(tty_port_register_device_serdev); | |
191 | ||
192 | /** | |
193 | * tty_port_unregister_device - deregister a tty or serdev device | |
194 | * @port: tty_port of the device | |
195 | * @driver: tty_driver for this device | |
196 | * @index: index of the tty | |
197 | * | |
198 | * If a tty or serdev device is registered with a call to | |
199 | * tty_port_register_device_serdev() then this function must be called when | |
200 | * the device is gone. | |
201 | */ | |
202 | void tty_port_unregister_device(struct tty_port *port, | |
203 | struct tty_driver *driver, unsigned index) | |
204 | { | |
205 | int ret; | |
206 | ||
207 | ret = serdev_tty_port_unregister(port); | |
208 | if (ret == 0) | |
209 | return; | |
210 | ||
211 | tty_unregister_device(driver, index); | |
212 | } | |
213 | EXPORT_SYMBOL_GPL(tty_port_unregister_device); | |
214 | ||
9e48565d AC |
215 | int tty_port_alloc_xmit_buf(struct tty_port *port) |
216 | { | |
217 | /* We may sleep in get_zeroed_page() */ | |
44e4909e | 218 | mutex_lock(&port->buf_mutex); |
9e48565d AC |
219 | if (port->xmit_buf == NULL) |
220 | port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); | |
44e4909e | 221 | mutex_unlock(&port->buf_mutex); |
9e48565d AC |
222 | if (port->xmit_buf == NULL) |
223 | return -ENOMEM; | |
224 | return 0; | |
225 | } | |
226 | EXPORT_SYMBOL(tty_port_alloc_xmit_buf); | |
227 | ||
228 | void tty_port_free_xmit_buf(struct tty_port *port) | |
229 | { | |
44e4909e | 230 | mutex_lock(&port->buf_mutex); |
9e48565d AC |
231 | if (port->xmit_buf != NULL) { |
232 | free_page((unsigned long)port->xmit_buf); | |
233 | port->xmit_buf = NULL; | |
234 | } | |
44e4909e | 235 | mutex_unlock(&port->buf_mutex); |
9e48565d AC |
236 | } |
237 | EXPORT_SYMBOL(tty_port_free_xmit_buf); | |
238 | ||
de274bfe JS |
239 | /** |
240 | * tty_port_destroy -- destroy inited port | |
1926e5d3 | 241 | * @port: tty port to be destroyed |
de274bfe JS |
242 | * |
243 | * When a port was initialized using tty_port_init, one has to destroy the | |
244 | * port by this function. Either indirectly by using tty_port refcounting | |
245 | * (tty_port_put) or directly if refcounting is not used. | |
246 | */ | |
247 | void tty_port_destroy(struct tty_port *port) | |
248 | { | |
e176058f | 249 | tty_buffer_cancel_work(port); |
de274bfe JS |
250 | tty_buffer_free_all(port); |
251 | } | |
252 | EXPORT_SYMBOL(tty_port_destroy); | |
253 | ||
568aafc6 AC |
254 | static void tty_port_destructor(struct kref *kref) |
255 | { | |
256 | struct tty_port *port = container_of(kref, struct tty_port, kref); | |
e3bfea23 PH |
257 | |
258 | /* check if last port ref was dropped before tty release */ | |
259 | if (WARN_ON(port->itty)) | |
260 | return; | |
568aafc6 AC |
261 | if (port->xmit_buf) |
262 | free_page((unsigned long)port->xmit_buf); | |
de274bfe | 263 | tty_port_destroy(port); |
81c79838 | 264 | if (port->ops && port->ops->destruct) |
568aafc6 AC |
265 | port->ops->destruct(port); |
266 | else | |
267 | kfree(port); | |
268 | } | |
269 | ||
270 | void tty_port_put(struct tty_port *port) | |
271 | { | |
272 | if (port) | |
273 | kref_put(&port->kref, tty_port_destructor); | |
274 | } | |
275 | EXPORT_SYMBOL(tty_port_put); | |
9e48565d | 276 | |
4a90f09b AC |
277 | /** |
278 | * tty_port_tty_get - get a tty reference | |
279 | * @port: tty port | |
280 | * | |
281 | * Return a refcount protected tty instance or NULL if the port is not | |
282 | * associated with a tty (eg due to close or hangup) | |
283 | */ | |
4a90f09b AC |
284 | struct tty_struct *tty_port_tty_get(struct tty_port *port) |
285 | { | |
286 | unsigned long flags; | |
287 | struct tty_struct *tty; | |
288 | ||
289 | spin_lock_irqsave(&port->lock, flags); | |
290 | tty = tty_kref_get(port->tty); | |
291 | spin_unlock_irqrestore(&port->lock, flags); | |
292 | return tty; | |
293 | } | |
294 | EXPORT_SYMBOL(tty_port_tty_get); | |
295 | ||
296 | /** | |
297 | * tty_port_tty_set - set the tty of a port | |
298 | * @port: tty port | |
299 | * @tty: the tty | |
300 | * | |
301 | * Associate the port and tty pair. Manages any internal refcounts. | |
302 | * Pass NULL to deassociate a port | |
303 | */ | |
4a90f09b AC |
304 | void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) |
305 | { | |
306 | unsigned long flags; | |
307 | ||
308 | spin_lock_irqsave(&port->lock, flags); | |
a211b1af | 309 | tty_kref_put(port->tty); |
cb4bca35 | 310 | port->tty = tty_kref_get(tty); |
4a90f09b AC |
311 | spin_unlock_irqrestore(&port->lock, flags); |
312 | } | |
313 | EXPORT_SYMBOL(tty_port_tty_set); | |
31f35939 | 314 | |
957dacae | 315 | static void tty_port_shutdown(struct tty_port *port, struct tty_struct *tty) |
7ca0ff9a | 316 | { |
64bc3979 | 317 | mutex_lock(&port->mutex); |
8bde9658 JH |
318 | if (port->console) |
319 | goto out; | |
320 | ||
d41861ca PH |
321 | if (tty_port_initialized(port)) { |
322 | tty_port_set_initialized(port, 0); | |
957dacae JH |
323 | /* |
324 | * Drop DTR/RTS if HUPCL is set. This causes any attached | |
325 | * modem to hang up the line. | |
326 | */ | |
327 | if (tty && C_HUPCL(tty)) | |
328 | tty_port_lower_dtr_rts(port); | |
329 | ||
0d3cb6f6 | 330 | if (port->ops->shutdown) |
7ca0ff9a | 331 | port->ops->shutdown(port); |
8bde9658 JH |
332 | } |
333 | out: | |
64bc3979 | 334 | mutex_unlock(&port->mutex); |
7ca0ff9a AC |
335 | } |
336 | ||
3e61696b AC |
337 | /** |
338 | * tty_port_hangup - hangup helper | |
339 | * @port: tty port | |
340 | * | |
341 | * Perform port level tty hangup flag and count changes. Drop the tty | |
342 | * reference. | |
9c9928bd PH |
343 | * |
344 | * Caller holds tty lock. | |
3e61696b | 345 | */ |
3e61696b AC |
346 | void tty_port_hangup(struct tty_port *port) |
347 | { | |
957dacae | 348 | struct tty_struct *tty; |
3e61696b AC |
349 | unsigned long flags; |
350 | ||
351 | spin_lock_irqsave(&port->lock, flags); | |
352 | port->count = 0; | |
957dacae JH |
353 | tty = port->tty; |
354 | if (tty) | |
355 | set_bit(TTY_IO_ERROR, &tty->flags); | |
3e61696b AC |
356 | port->tty = NULL; |
357 | spin_unlock_irqrestore(&port->lock, flags); | |
807c8d81 | 358 | tty_port_set_active(port, 0); |
957dacae JH |
359 | tty_port_shutdown(port, tty); |
360 | tty_kref_put(tty); | |
3e61696b | 361 | wake_up_interruptible(&port->open_wait); |
bdc04e31 | 362 | wake_up_interruptible(&port->delta_msr_wait); |
3e61696b AC |
363 | } |
364 | EXPORT_SYMBOL(tty_port_hangup); | |
365 | ||
aa27a094 JS |
366 | /** |
367 | * tty_port_tty_hangup - helper to hang up a tty | |
368 | * | |
369 | * @port: tty port | |
370 | * @check_clocal: hang only ttys with CLOCAL unset? | |
371 | */ | |
372 | void tty_port_tty_hangup(struct tty_port *port, bool check_clocal) | |
373 | { | |
374 | struct tty_struct *tty = tty_port_tty_get(port); | |
375 | ||
1d9e689c | 376 | if (tty && (!check_clocal || !C_CLOCAL(tty))) |
aa27a094 | 377 | tty_hangup(tty); |
1d9e689c | 378 | tty_kref_put(tty); |
aa27a094 JS |
379 | } |
380 | EXPORT_SYMBOL_GPL(tty_port_tty_hangup); | |
381 | ||
6aad04f2 JS |
382 | /** |
383 | * tty_port_tty_wakeup - helper to wake up a tty | |
384 | * | |
385 | * @port: tty port | |
386 | */ | |
387 | void tty_port_tty_wakeup(struct tty_port *port) | |
388 | { | |
c3485ee0 | 389 | port->client_ops->write_wakeup(port); |
6aad04f2 JS |
390 | } |
391 | EXPORT_SYMBOL_GPL(tty_port_tty_wakeup); | |
392 | ||
31f35939 AC |
393 | /** |
394 | * tty_port_carrier_raised - carrier raised check | |
395 | * @port: tty port | |
396 | * | |
397 | * Wrapper for the carrier detect logic. For the moment this is used | |
398 | * to hide some internal details. This will eventually become entirely | |
399 | * internal to the tty port. | |
400 | */ | |
31f35939 AC |
401 | int tty_port_carrier_raised(struct tty_port *port) |
402 | { | |
0d3cb6f6 | 403 | if (port->ops->carrier_raised == NULL) |
31f35939 AC |
404 | return 1; |
405 | return port->ops->carrier_raised(port); | |
406 | } | |
407 | EXPORT_SYMBOL(tty_port_carrier_raised); | |
5d951fb4 AC |
408 | |
409 | /** | |
fcc8ac18 | 410 | * tty_port_raise_dtr_rts - Raise DTR/RTS |
5d951fb4 AC |
411 | * @port: tty port |
412 | * | |
413 | * Wrapper for the DTR/RTS raise logic. For the moment this is used | |
414 | * to hide some internal details. This will eventually become entirely | |
415 | * internal to the tty port. | |
416 | */ | |
5d951fb4 AC |
417 | void tty_port_raise_dtr_rts(struct tty_port *port) |
418 | { | |
0d3cb6f6 | 419 | if (port->ops->dtr_rts) |
fcc8ac18 | 420 | port->ops->dtr_rts(port, 1); |
5d951fb4 AC |
421 | } |
422 | EXPORT_SYMBOL(tty_port_raise_dtr_rts); | |
36c621d8 | 423 | |
fcc8ac18 AC |
424 | /** |
425 | * tty_port_lower_dtr_rts - Lower DTR/RTS | |
426 | * @port: tty port | |
427 | * | |
428 | * Wrapper for the DTR/RTS raise logic. For the moment this is used | |
429 | * to hide some internal details. This will eventually become entirely | |
430 | * internal to the tty port. | |
431 | */ | |
fcc8ac18 AC |
432 | void tty_port_lower_dtr_rts(struct tty_port *port) |
433 | { | |
0d3cb6f6 | 434 | if (port->ops->dtr_rts) |
fcc8ac18 AC |
435 | port->ops->dtr_rts(port, 0); |
436 | } | |
437 | EXPORT_SYMBOL(tty_port_lower_dtr_rts); | |
438 | ||
36c621d8 AC |
439 | /** |
440 | * tty_port_block_til_ready - Waiting logic for tty open | |
441 | * @port: the tty port being opened | |
442 | * @tty: the tty device being bound | |
ed3f0af8 | 443 | * @filp: the file pointer of the opener or NULL |
36c621d8 AC |
444 | * |
445 | * Implement the core POSIX/SuS tty behaviour when opening a tty device. | |
446 | * Handles: | |
447 | * - hangup (both before and during) | |
448 | * - non blocking open | |
449 | * - rts/dtr/dcd | |
450 | * - signals | |
451 | * - port flags and counts | |
452 | * | |
453 | * The passed tty_port must implement the carrier_raised method if it can | |
fcc8ac18 | 454 | * do carrier detect and the dtr_rts method if it supports software |
36c621d8 AC |
455 | * management of these lines. Note that the dtr/rts raise is done each |
456 | * iteration as a hangup may have previously dropped them while we wait. | |
c590f6b6 PH |
457 | * |
458 | * Caller holds tty lock. | |
459 | * | |
460 | * NB: May drop and reacquire tty lock when blocking, so tty and tty_port | |
461 | * may have changed state (eg., may have been hung up). | |
36c621d8 | 462 | */ |
36c621d8 AC |
463 | int tty_port_block_til_ready(struct tty_port *port, |
464 | struct tty_struct *tty, struct file *filp) | |
465 | { | |
466 | int do_clocal = 0, retval; | |
467 | unsigned long flags; | |
6af9a43d | 468 | DEFINE_WAIT(wait); |
36c621d8 | 469 | |
36c621d8 | 470 | /* if non-blocking mode is set we can pass directly to open unless |
1df92640 XT |
471 | * the port has just hung up or is in another error state. |
472 | */ | |
18900ca6 | 473 | if (tty_io_error(tty)) { |
807c8d81 | 474 | tty_port_set_active(port, 1); |
8627b96d AC |
475 | return 0; |
476 | } | |
ed3f0af8 | 477 | if (filp == NULL || (filp->f_flags & O_NONBLOCK)) { |
4175f3e3 | 478 | /* Indicate we are open */ |
9db276f8 | 479 | if (C_BAUD(tty)) |
4175f3e3 | 480 | tty_port_raise_dtr_rts(port); |
807c8d81 | 481 | tty_port_set_active(port, 1); |
36c621d8 AC |
482 | return 0; |
483 | } | |
484 | ||
485 | if (C_CLOCAL(tty)) | |
486 | do_clocal = 1; | |
487 | ||
488 | /* Block waiting until we can proceed. We may need to wait for the | |
1df92640 XT |
489 | * carrier, but we must also wait for any close that is in progress |
490 | * before the next open may complete. | |
491 | */ | |
36c621d8 AC |
492 | |
493 | retval = 0; | |
36c621d8 AC |
494 | |
495 | /* The port lock protects the port counts */ | |
496 | spin_lock_irqsave(&port->lock, flags); | |
e359a4e3 | 497 | port->count--; |
36c621d8 AC |
498 | port->blocked_open++; |
499 | spin_unlock_irqrestore(&port->lock, flags); | |
500 | ||
501 | while (1) { | |
502 | /* Indicate we are open */ | |
d41861ca | 503 | if (C_BAUD(tty) && tty_port_initialized(port)) |
7834909f | 504 | tty_port_raise_dtr_rts(port); |
36c621d8 | 505 | |
3e3b5c08 | 506 | prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE); |
d774a56d | 507 | /* Check for a hangup or uninitialised port. |
1df92640 XT |
508 | * Return accordingly. |
509 | */ | |
d41861ca | 510 | if (tty_hung_up_p(filp) || !tty_port_initialized(port)) { |
36c621d8 AC |
511 | if (port->flags & ASYNC_HUP_NOTIFY) |
512 | retval = -EAGAIN; | |
513 | else | |
514 | retval = -ERESTARTSYS; | |
515 | break; | |
516 | } | |
0eee50af JS |
517 | /* |
518 | * Probe the carrier. For devices with no carrier detect | |
519 | * tty_port_carrier_raised will always return true. | |
520 | * Never ask drivers if CLOCAL is set, this causes troubles | |
521 | * on some hardware. | |
522 | */ | |
fef062cb | 523 | if (do_clocal || tty_port_carrier_raised(port)) |
36c621d8 AC |
524 | break; |
525 | if (signal_pending(current)) { | |
526 | retval = -ERESTARTSYS; | |
527 | break; | |
528 | } | |
89c8d91e | 529 | tty_unlock(tty); |
36c621d8 | 530 | schedule(); |
89c8d91e | 531 | tty_lock(tty); |
36c621d8 | 532 | } |
3e3b5c08 | 533 | finish_wait(&port->open_wait, &wait); |
36c621d8 AC |
534 | |
535 | /* Update counts. A parallel hangup will have set count to zero and | |
1df92640 XT |
536 | * we must not mess that up further. |
537 | */ | |
36c621d8 AC |
538 | spin_lock_irqsave(&port->lock, flags); |
539 | if (!tty_hung_up_p(filp)) | |
540 | port->count++; | |
541 | port->blocked_open--; | |
36c621d8 | 542 | spin_unlock_irqrestore(&port->lock, flags); |
807c8d81 PH |
543 | if (retval == 0) |
544 | tty_port_set_active(port, 1); | |
ecc2e05e | 545 | return retval; |
36c621d8 AC |
546 | } |
547 | EXPORT_SYMBOL(tty_port_block_til_ready); | |
548 | ||
b74414f5 JH |
549 | static void tty_port_drain_delay(struct tty_port *port, struct tty_struct *tty) |
550 | { | |
551 | unsigned int bps = tty_get_baud_rate(tty); | |
552 | long timeout; | |
553 | ||
554 | if (bps > 1200) { | |
555 | timeout = (HZ * 10 * port->drain_delay) / bps; | |
556 | timeout = max_t(long, timeout, HZ / 10); | |
557 | } else { | |
558 | timeout = 2 * HZ; | |
559 | } | |
560 | schedule_timeout_interruptible(timeout); | |
561 | } | |
562 | ||
79c1faa4 | 563 | /* Caller holds tty lock. */ |
d774a56d AC |
564 | int tty_port_close_start(struct tty_port *port, |
565 | struct tty_struct *tty, struct file *filp) | |
a6614999 AC |
566 | { |
567 | unsigned long flags; | |
568 | ||
633caba8 | 569 | if (tty_hung_up_p(filp)) |
a6614999 | 570 | return 0; |
a6614999 | 571 | |
633caba8 | 572 | spin_lock_irqsave(&port->lock, flags); |
d774a56d | 573 | if (tty->count == 1 && port->count != 1) { |
339f36ba PH |
574 | tty_warn(tty, "%s: tty->count = 1 port count = %d\n", __func__, |
575 | port->count); | |
a6614999 AC |
576 | port->count = 1; |
577 | } | |
578 | if (--port->count < 0) { | |
339f36ba PH |
579 | tty_warn(tty, "%s: bad port count (%d)\n", __func__, |
580 | port->count); | |
a6614999 AC |
581 | port->count = 0; |
582 | } | |
583 | ||
584 | if (port->count) { | |
585 | spin_unlock_irqrestore(&port->lock, flags); | |
586 | return 0; | |
587 | } | |
a6614999 | 588 | spin_unlock_irqrestore(&port->lock, flags); |
0b2588ca | 589 | |
ddc7b758 PH |
590 | tty->closing = 1; |
591 | ||
d41861ca | 592 | if (tty_port_initialized(port)) { |
0b2588ca | 593 | /* Don't block on a stalled port, just pull the chain */ |
6e94dbc7 | 594 | if (tty->flow.tco_stopped) |
0b2588ca JH |
595 | tty_driver_flush_buffer(tty); |
596 | if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) | |
79c1faa4 | 597 | tty_wait_until_sent(tty, port->closing_wait); |
0b2588ca JH |
598 | if (port->drain_delay) |
599 | tty_port_drain_delay(port, tty); | |
600 | } | |
e707c35c AC |
601 | /* Flush the ldisc buffering */ |
602 | tty_ldisc_flush(tty); | |
603 | ||
469d6d06 | 604 | /* Report to caller this is the last port reference */ |
a6614999 AC |
605 | return 1; |
606 | } | |
607 | EXPORT_SYMBOL(tty_port_close_start); | |
608 | ||
0733db91 | 609 | /* Caller holds tty lock */ |
a6614999 AC |
610 | void tty_port_close_end(struct tty_port *port, struct tty_struct *tty) |
611 | { | |
612 | unsigned long flags; | |
613 | ||
3f40f5b2 | 614 | tty_ldisc_flush(tty); |
a6614999 AC |
615 | tty->closing = 0; |
616 | ||
ddc7b758 PH |
617 | spin_lock_irqsave(&port->lock, flags); |
618 | ||
a6614999 AC |
619 | if (port->blocked_open) { |
620 | spin_unlock_irqrestore(&port->lock, flags); | |
5823323e PH |
621 | if (port->close_delay) |
622 | msleep_interruptible(jiffies_to_msecs(port->close_delay)); | |
a6614999 AC |
623 | spin_lock_irqsave(&port->lock, flags); |
624 | wake_up_interruptible(&port->open_wait); | |
625 | } | |
a6614999 | 626 | spin_unlock_irqrestore(&port->lock, flags); |
807c8d81 | 627 | tty_port_set_active(port, 0); |
a6614999 AC |
628 | } |
629 | EXPORT_SYMBOL(tty_port_close_end); | |
7ca0ff9a | 630 | |
1b1deb44 | 631 | /* |
0733db91 PH |
632 | * tty_port_close |
633 | * | |
634 | * Caller holds tty lock | |
0733db91 | 635 | */ |
7ca0ff9a AC |
636 | void tty_port_close(struct tty_port *port, struct tty_struct *tty, |
637 | struct file *filp) | |
638 | { | |
639 | if (tty_port_close_start(port, tty, filp) == 0) | |
640 | return; | |
957dacae | 641 | tty_port_shutdown(port, tty); |
2a486026 CP |
642 | if (!port->console) |
643 | set_bit(TTY_IO_ERROR, &tty->flags); | |
7ca0ff9a AC |
644 | tty_port_close_end(port, tty); |
645 | tty_port_tty_set(port, NULL); | |
646 | } | |
647 | EXPORT_SYMBOL(tty_port_close); | |
64bc3979 | 648 | |
72a33bf5 JS |
649 | /** |
650 | * tty_port_install - generic tty->ops->install handler | |
651 | * @port: tty_port of the device | |
652 | * @driver: tty_driver for this device | |
653 | * @tty: tty to be installed | |
654 | * | |
655 | * It is the same as tty_standard_install except the provided @port is linked | |
656 | * to a concrete tty specified by @tty. Use this or tty_port_register_device | |
657 | * (or both). Call tty_port_link_device as a last resort. | |
658 | */ | |
695586ca JS |
659 | int tty_port_install(struct tty_port *port, struct tty_driver *driver, |
660 | struct tty_struct *tty) | |
661 | { | |
662 | tty->port = port; | |
663 | return tty_standard_install(driver, tty); | |
664 | } | |
665 | EXPORT_SYMBOL_GPL(tty_port_install); | |
666 | ||
1b1deb44 | 667 | /* |
addd4672 PH |
668 | * tty_port_open |
669 | * | |
670 | * Caller holds tty lock. | |
671 | * | |
672 | * NB: may drop and reacquire tty lock (in tty_port_block_til_ready()) so | |
673 | * tty and tty_port may have changed state (eg., may be hung up now) | |
674 | */ | |
64bc3979 | 675 | int tty_port_open(struct tty_port *port, struct tty_struct *tty, |
d774a56d | 676 | struct file *filp) |
64bc3979 AC |
677 | { |
678 | spin_lock_irq(&port->lock); | |
e359a4e3 | 679 | ++port->count; |
64bc3979 AC |
680 | spin_unlock_irq(&port->lock); |
681 | tty_port_tty_set(port, tty); | |
682 | ||
683 | /* | |
684 | * Do the device-specific open only if the hardware isn't | |
685 | * already initialized. Serialize open and shutdown using the | |
686 | * port mutex. | |
687 | */ | |
688 | ||
689 | mutex_lock(&port->mutex); | |
690 | ||
d41861ca | 691 | if (!tty_port_initialized(port)) { |
a9a37ec3 | 692 | clear_bit(TTY_IO_ERROR, &tty->flags); |
0d3cb6f6 | 693 | if (port->ops->activate) { |
64bc3979 | 694 | int retval = port->ops->activate(port, tty); |
54ad59a2 | 695 | |
64bc3979 | 696 | if (retval) { |
d774a56d AC |
697 | mutex_unlock(&port->mutex); |
698 | return retval; | |
699 | } | |
700 | } | |
d41861ca | 701 | tty_port_set_initialized(port, 1); |
64bc3979 AC |
702 | } |
703 | mutex_unlock(&port->mutex); | |
704 | return tty_port_block_til_ready(port, tty, filp); | |
705 | } | |
64bc3979 | 706 | EXPORT_SYMBOL(tty_port_open); |