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