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Commit | Line | Data |
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9e48565d AC |
1 | /* |
2 | * Tty port functions | |
3 | */ | |
4 | ||
5 | #include <linux/types.h> | |
6 | #include <linux/errno.h> | |
7 | #include <linux/tty.h> | |
8 | #include <linux/tty_driver.h> | |
9 | #include <linux/tty_flip.h> | |
3e61696b | 10 | #include <linux/serial.h> |
9e48565d AC |
11 | #include <linux/timer.h> |
12 | #include <linux/string.h> | |
13 | #include <linux/slab.h> | |
174cd4b1 | 14 | #include <linux/sched/signal.h> |
9e48565d AC |
15 | #include <linux/wait.h> |
16 | #include <linux/bitops.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/module.h> | |
8cde11b2 | 19 | #include <linux/serdev.h> |
9e48565d | 20 | |
c3485ee0 RH |
21 | static int tty_port_default_receive_buf(struct tty_port *port, |
22 | const unsigned char *p, | |
23 | const unsigned char *f, size_t count) | |
24 | { | |
25 | int ret; | |
26 | struct tty_struct *tty; | |
27 | struct tty_ldisc *disc; | |
28 | ||
29 | tty = READ_ONCE(port->itty); | |
30 | if (!tty) | |
31 | return 0; | |
32 | ||
33 | disc = tty_ldisc_ref(tty); | |
34 | if (!disc) | |
35 | return 0; | |
36 | ||
925bb1ce | 37 | mutex_lock(&tty->atomic_write_lock); |
c3485ee0 | 38 | ret = tty_ldisc_receive_buf(disc, p, (char *)f, count); |
925bb1ce | 39 | mutex_unlock(&tty->atomic_write_lock); |
c3485ee0 RH |
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 | ||
56 | static const struct tty_port_client_operations default_client_ops = { | |
57 | .receive_buf = tty_port_default_receive_buf, | |
58 | .write_wakeup = tty_port_default_wakeup, | |
59 | }; | |
60 | ||
9e48565d AC |
61 | void tty_port_init(struct tty_port *port) |
62 | { | |
63 | memset(port, 0, sizeof(*port)); | |
ecbbfd44 | 64 | tty_buffer_init(port); |
9e48565d | 65 | init_waitqueue_head(&port->open_wait); |
bdc04e31 | 66 | init_waitqueue_head(&port->delta_msr_wait); |
9e48565d | 67 | mutex_init(&port->mutex); |
44e4909e | 68 | mutex_init(&port->buf_mutex); |
4a90f09b | 69 | spin_lock_init(&port->lock); |
9e48565d AC |
70 | port->close_delay = (50 * HZ) / 100; |
71 | port->closing_wait = (3000 * HZ) / 100; | |
c3485ee0 | 72 | port->client_ops = &default_client_ops; |
568aafc6 | 73 | kref_init(&port->kref); |
9e48565d AC |
74 | } |
75 | EXPORT_SYMBOL(tty_port_init); | |
76 | ||
2cb4ca02 JS |
77 | /** |
78 | * tty_port_link_device - link tty and tty_port | |
79 | * @port: tty_port of the device | |
80 | * @driver: tty_driver for this device | |
81 | * @index: index of the tty | |
82 | * | |
83 | * Provide the tty layer wit ha link from a tty (specified by @index) to a | |
84 | * tty_port (@port). Use this only if neither tty_port_register_device nor | |
85 | * tty_port_install is used in the driver. If used, this has to be called before | |
86 | * tty_register_driver. | |
87 | */ | |
88 | void tty_port_link_device(struct tty_port *port, | |
89 | struct tty_driver *driver, unsigned index) | |
90 | { | |
91 | if (WARN_ON(index >= driver->num)) | |
92 | return; | |
93 | driver->ports[index] = port; | |
94 | } | |
95 | EXPORT_SYMBOL_GPL(tty_port_link_device); | |
96 | ||
72a33bf5 JS |
97 | /** |
98 | * tty_port_register_device - register tty device | |
99 | * @port: tty_port of the device | |
100 | * @driver: tty_driver for this device | |
101 | * @index: index of the tty | |
102 | * @device: parent if exists, otherwise NULL | |
103 | * | |
104 | * It is the same as tty_register_device except the provided @port is linked to | |
105 | * a concrete tty specified by @index. Use this or tty_port_install (or both). | |
106 | * Call tty_port_link_device as a last resort. | |
107 | */ | |
057eb856 JS |
108 | struct device *tty_port_register_device(struct tty_port *port, |
109 | struct tty_driver *driver, unsigned index, | |
110 | struct device *device) | |
111 | { | |
3086365d | 112 | return tty_port_register_device_attr(port, driver, index, device, NULL, NULL); |
057eb856 JS |
113 | } |
114 | EXPORT_SYMBOL_GPL(tty_port_register_device); | |
115 | ||
b1b79916 TH |
116 | /** |
117 | * tty_port_register_device_attr - register tty device | |
118 | * @port: tty_port of the device | |
119 | * @driver: tty_driver for this device | |
120 | * @index: index of the tty | |
121 | * @device: parent if exists, otherwise NULL | |
122 | * @drvdata: Driver data to be set to device. | |
123 | * @attr_grp: Attribute group to be set on device. | |
124 | * | |
125 | * It is the same as tty_register_device_attr except the provided @port is | |
126 | * linked to a concrete tty specified by @index. Use this or tty_port_install | |
127 | * (or both). Call tty_port_link_device as a last resort. | |
128 | */ | |
129 | struct device *tty_port_register_device_attr(struct tty_port *port, | |
130 | struct tty_driver *driver, unsigned index, | |
131 | struct device *device, void *drvdata, | |
132 | const struct attribute_group **attr_grp) | |
133 | { | |
134 | tty_port_link_device(port, driver, index); | |
135 | return tty_register_device_attr(driver, index, device, drvdata, | |
136 | attr_grp); | |
137 | } | |
138 | EXPORT_SYMBOL_GPL(tty_port_register_device_attr); | |
139 | ||
8cde11b2 JH |
140 | /** |
141 | * tty_port_register_device_attr_serdev - register tty or serdev device | |
142 | * @port: tty_port of the device | |
143 | * @driver: tty_driver for this device | |
144 | * @index: index of the tty | |
145 | * @device: parent if exists, otherwise NULL | |
146 | * @drvdata: driver data for the device | |
147 | * @attr_grp: attribute group for the device | |
148 | * | |
149 | * Register a serdev or tty device depending on if the parent device has any | |
150 | * defined serdev clients or not. | |
151 | */ | |
152 | struct device *tty_port_register_device_attr_serdev(struct tty_port *port, | |
153 | struct tty_driver *driver, unsigned index, | |
154 | struct device *device, void *drvdata, | |
155 | const struct attribute_group **attr_grp) | |
156 | { | |
157 | struct device *dev; | |
158 | ||
159 | tty_port_link_device(port, driver, index); | |
160 | ||
161 | dev = serdev_tty_port_register(port, device, driver, index); | |
162 | if (PTR_ERR(dev) != -ENODEV) { | |
163 | /* Skip creating cdev if we registered a serdev device */ | |
164 | return dev; | |
165 | } | |
166 | ||
167 | return tty_register_device_attr(driver, index, device, drvdata, | |
168 | attr_grp); | |
169 | } | |
170 | EXPORT_SYMBOL_GPL(tty_port_register_device_attr_serdev); | |
171 | ||
172 | /** | |
173 | * tty_port_register_device_serdev - register tty or serdev device | |
174 | * @port: tty_port of the device | |
175 | * @driver: tty_driver for this device | |
176 | * @index: index of the tty | |
177 | * @device: parent if exists, otherwise NULL | |
178 | * | |
179 | * Register a serdev or tty device depending on if the parent device has any | |
180 | * defined serdev clients or not. | |
181 | */ | |
182 | struct device *tty_port_register_device_serdev(struct tty_port *port, | |
183 | struct tty_driver *driver, unsigned index, | |
184 | struct device *device) | |
185 | { | |
186 | return tty_port_register_device_attr_serdev(port, driver, index, | |
187 | device, NULL, NULL); | |
188 | } | |
189 | EXPORT_SYMBOL_GPL(tty_port_register_device_serdev); | |
190 | ||
191 | /** | |
192 | * tty_port_unregister_device - deregister a tty or serdev device | |
193 | * @port: tty_port of the device | |
194 | * @driver: tty_driver for this device | |
195 | * @index: index of the tty | |
196 | * | |
197 | * If a tty or serdev device is registered with a call to | |
198 | * tty_port_register_device_serdev() then this function must be called when | |
199 | * the device is gone. | |
200 | */ | |
201 | void tty_port_unregister_device(struct tty_port *port, | |
202 | struct tty_driver *driver, unsigned index) | |
203 | { | |
204 | int ret; | |
205 | ||
206 | ret = serdev_tty_port_unregister(port); | |
207 | if (ret == 0) | |
208 | return; | |
209 | ||
210 | tty_unregister_device(driver, index); | |
211 | } | |
212 | EXPORT_SYMBOL_GPL(tty_port_unregister_device); | |
213 | ||
9e48565d AC |
214 | int tty_port_alloc_xmit_buf(struct tty_port *port) |
215 | { | |
216 | /* We may sleep in get_zeroed_page() */ | |
44e4909e | 217 | mutex_lock(&port->buf_mutex); |
9e48565d AC |
218 | if (port->xmit_buf == NULL) |
219 | port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); | |
44e4909e | 220 | mutex_unlock(&port->buf_mutex); |
9e48565d AC |
221 | if (port->xmit_buf == NULL) |
222 | return -ENOMEM; | |
223 | return 0; | |
224 | } | |
225 | EXPORT_SYMBOL(tty_port_alloc_xmit_buf); | |
226 | ||
227 | void tty_port_free_xmit_buf(struct tty_port *port) | |
228 | { | |
44e4909e | 229 | mutex_lock(&port->buf_mutex); |
9e48565d AC |
230 | if (port->xmit_buf != NULL) { |
231 | free_page((unsigned long)port->xmit_buf); | |
232 | port->xmit_buf = NULL; | |
233 | } | |
44e4909e | 234 | mutex_unlock(&port->buf_mutex); |
9e48565d AC |
235 | } |
236 | EXPORT_SYMBOL(tty_port_free_xmit_buf); | |
237 | ||
de274bfe JS |
238 | /** |
239 | * tty_port_destroy -- destroy inited port | |
240 | * @port: tty port to be doestroyed | |
241 | * | |
242 | * When a port was initialized using tty_port_init, one has to destroy the | |
243 | * port by this function. Either indirectly by using tty_port refcounting | |
244 | * (tty_port_put) or directly if refcounting is not used. | |
245 | */ | |
246 | void tty_port_destroy(struct tty_port *port) | |
247 | { | |
e176058f | 248 | tty_buffer_cancel_work(port); |
de274bfe JS |
249 | tty_buffer_free_all(port); |
250 | } | |
251 | EXPORT_SYMBOL(tty_port_destroy); | |
252 | ||
568aafc6 AC |
253 | static void tty_port_destructor(struct kref *kref) |
254 | { | |
255 | struct tty_port *port = container_of(kref, struct tty_port, kref); | |
e3bfea23 PH |
256 | |
257 | /* check if last port ref was dropped before tty release */ | |
258 | if (WARN_ON(port->itty)) | |
259 | return; | |
568aafc6 AC |
260 | if (port->xmit_buf) |
261 | free_page((unsigned long)port->xmit_buf); | |
de274bfe | 262 | tty_port_destroy(port); |
81c79838 | 263 | if (port->ops && port->ops->destruct) |
568aafc6 AC |
264 | port->ops->destruct(port); |
265 | else | |
266 | kfree(port); | |
267 | } | |
268 | ||
269 | void tty_port_put(struct tty_port *port) | |
270 | { | |
271 | if (port) | |
272 | kref_put(&port->kref, tty_port_destructor); | |
273 | } | |
274 | EXPORT_SYMBOL(tty_port_put); | |
9e48565d | 275 | |
4a90f09b AC |
276 | /** |
277 | * tty_port_tty_get - get a tty reference | |
278 | * @port: tty port | |
279 | * | |
280 | * Return a refcount protected tty instance or NULL if the port is not | |
281 | * associated with a tty (eg due to close or hangup) | |
282 | */ | |
283 | ||
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 | */ | |
304 | ||
305 | void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) | |
306 | { | |
307 | unsigned long flags; | |
308 | ||
309 | spin_lock_irqsave(&port->lock, flags); | |
a211b1af | 310 | tty_kref_put(port->tty); |
cb4bca35 | 311 | port->tty = tty_kref_get(tty); |
4a90f09b AC |
312 | spin_unlock_irqrestore(&port->lock, flags); |
313 | } | |
314 | EXPORT_SYMBOL(tty_port_tty_set); | |
31f35939 | 315 | |
957dacae | 316 | static void tty_port_shutdown(struct tty_port *port, struct tty_struct *tty) |
7ca0ff9a | 317 | { |
64bc3979 | 318 | mutex_lock(&port->mutex); |
8bde9658 JH |
319 | if (port->console) |
320 | goto out; | |
321 | ||
d41861ca PH |
322 | if (tty_port_initialized(port)) { |
323 | tty_port_set_initialized(port, 0); | |
957dacae JH |
324 | /* |
325 | * Drop DTR/RTS if HUPCL is set. This causes any attached | |
326 | * modem to hang up the line. | |
327 | */ | |
328 | if (tty && C_HUPCL(tty)) | |
329 | tty_port_lower_dtr_rts(port); | |
330 | ||
8bde9658 | 331 | if (port->ops->shutdown) |
7ca0ff9a | 332 | port->ops->shutdown(port); |
8bde9658 JH |
333 | } |
334 | out: | |
64bc3979 | 335 | mutex_unlock(&port->mutex); |
7ca0ff9a AC |
336 | } |
337 | ||
3e61696b AC |
338 | /** |
339 | * tty_port_hangup - hangup helper | |
340 | * @port: tty port | |
341 | * | |
342 | * Perform port level tty hangup flag and count changes. Drop the tty | |
343 | * reference. | |
9c9928bd PH |
344 | * |
345 | * Caller holds tty lock. | |
3e61696b AC |
346 | */ |
347 | ||
348 | void tty_port_hangup(struct tty_port *port) | |
349 | { | |
957dacae | 350 | struct tty_struct *tty; |
3e61696b AC |
351 | unsigned long flags; |
352 | ||
353 | spin_lock_irqsave(&port->lock, flags); | |
354 | port->count = 0; | |
957dacae JH |
355 | tty = port->tty; |
356 | if (tty) | |
357 | set_bit(TTY_IO_ERROR, &tty->flags); | |
3e61696b AC |
358 | port->tty = NULL; |
359 | spin_unlock_irqrestore(&port->lock, flags); | |
807c8d81 | 360 | tty_port_set_active(port, 0); |
957dacae JH |
361 | tty_port_shutdown(port, tty); |
362 | tty_kref_put(tty); | |
3e61696b | 363 | wake_up_interruptible(&port->open_wait); |
bdc04e31 | 364 | wake_up_interruptible(&port->delta_msr_wait); |
3e61696b AC |
365 | } |
366 | EXPORT_SYMBOL(tty_port_hangup); | |
367 | ||
aa27a094 JS |
368 | /** |
369 | * tty_port_tty_hangup - helper to hang up a tty | |
370 | * | |
371 | * @port: tty port | |
372 | * @check_clocal: hang only ttys with CLOCAL unset? | |
373 | */ | |
374 | void tty_port_tty_hangup(struct tty_port *port, bool check_clocal) | |
375 | { | |
376 | struct tty_struct *tty = tty_port_tty_get(port); | |
377 | ||
1d9e689c | 378 | if (tty && (!check_clocal || !C_CLOCAL(tty))) |
aa27a094 | 379 | tty_hangup(tty); |
1d9e689c | 380 | tty_kref_put(tty); |
aa27a094 JS |
381 | } |
382 | EXPORT_SYMBOL_GPL(tty_port_tty_hangup); | |
383 | ||
6aad04f2 JS |
384 | /** |
385 | * tty_port_tty_wakeup - helper to wake up a tty | |
386 | * | |
387 | * @port: tty port | |
388 | */ | |
389 | void tty_port_tty_wakeup(struct tty_port *port) | |
390 | { | |
c3485ee0 | 391 | port->client_ops->write_wakeup(port); |
6aad04f2 JS |
392 | } |
393 | EXPORT_SYMBOL_GPL(tty_port_tty_wakeup); | |
394 | ||
31f35939 AC |
395 | /** |
396 | * tty_port_carrier_raised - carrier raised check | |
397 | * @port: tty port | |
398 | * | |
399 | * Wrapper for the carrier detect logic. For the moment this is used | |
400 | * to hide some internal details. This will eventually become entirely | |
401 | * internal to the tty port. | |
402 | */ | |
403 | ||
404 | int tty_port_carrier_raised(struct tty_port *port) | |
405 | { | |
406 | if (port->ops->carrier_raised == NULL) | |
407 | return 1; | |
408 | return port->ops->carrier_raised(port); | |
409 | } | |
410 | EXPORT_SYMBOL(tty_port_carrier_raised); | |
5d951fb4 AC |
411 | |
412 | /** | |
fcc8ac18 | 413 | * tty_port_raise_dtr_rts - Raise DTR/RTS |
5d951fb4 AC |
414 | * @port: tty port |
415 | * | |
416 | * Wrapper for the DTR/RTS raise logic. For the moment this is used | |
417 | * to hide some internal details. This will eventually become entirely | |
418 | * internal to the tty port. | |
419 | */ | |
420 | ||
421 | void tty_port_raise_dtr_rts(struct tty_port *port) | |
422 | { | |
fcc8ac18 AC |
423 | if (port->ops->dtr_rts) |
424 | port->ops->dtr_rts(port, 1); | |
5d951fb4 AC |
425 | } |
426 | EXPORT_SYMBOL(tty_port_raise_dtr_rts); | |
36c621d8 | 427 | |
fcc8ac18 AC |
428 | /** |
429 | * tty_port_lower_dtr_rts - Lower DTR/RTS | |
430 | * @port: tty port | |
431 | * | |
432 | * Wrapper for the DTR/RTS raise logic. For the moment this is used | |
433 | * to hide some internal details. This will eventually become entirely | |
434 | * internal to the tty port. | |
435 | */ | |
436 | ||
437 | void tty_port_lower_dtr_rts(struct tty_port *port) | |
438 | { | |
439 | if (port->ops->dtr_rts) | |
440 | port->ops->dtr_rts(port, 0); | |
441 | } | |
442 | EXPORT_SYMBOL(tty_port_lower_dtr_rts); | |
443 | ||
36c621d8 AC |
444 | /** |
445 | * tty_port_block_til_ready - Waiting logic for tty open | |
446 | * @port: the tty port being opened | |
447 | * @tty: the tty device being bound | |
ed3f0af8 | 448 | * @filp: the file pointer of the opener or NULL |
36c621d8 AC |
449 | * |
450 | * Implement the core POSIX/SuS tty behaviour when opening a tty device. | |
451 | * Handles: | |
452 | * - hangup (both before and during) | |
453 | * - non blocking open | |
454 | * - rts/dtr/dcd | |
455 | * - signals | |
456 | * - port flags and counts | |
457 | * | |
458 | * The passed tty_port must implement the carrier_raised method if it can | |
fcc8ac18 | 459 | * do carrier detect and the dtr_rts method if it supports software |
36c621d8 AC |
460 | * management of these lines. Note that the dtr/rts raise is done each |
461 | * iteration as a hangup may have previously dropped them while we wait. | |
c590f6b6 PH |
462 | * |
463 | * Caller holds tty lock. | |
464 | * | |
465 | * NB: May drop and reacquire tty lock when blocking, so tty and tty_port | |
466 | * may have changed state (eg., may have been hung up). | |
36c621d8 | 467 | */ |
d774a56d | 468 | |
36c621d8 AC |
469 | int tty_port_block_til_ready(struct tty_port *port, |
470 | struct tty_struct *tty, struct file *filp) | |
471 | { | |
472 | int do_clocal = 0, retval; | |
473 | unsigned long flags; | |
6af9a43d | 474 | DEFINE_WAIT(wait); |
36c621d8 | 475 | |
36c621d8 AC |
476 | /* if non-blocking mode is set we can pass directly to open unless |
477 | the port has just hung up or is in another error state */ | |
18900ca6 | 478 | if (tty_io_error(tty)) { |
807c8d81 | 479 | tty_port_set_active(port, 1); |
8627b96d AC |
480 | return 0; |
481 | } | |
ed3f0af8 | 482 | if (filp == NULL || (filp->f_flags & O_NONBLOCK)) { |
4175f3e3 | 483 | /* Indicate we are open */ |
9db276f8 | 484 | if (C_BAUD(tty)) |
4175f3e3 | 485 | tty_port_raise_dtr_rts(port); |
807c8d81 | 486 | tty_port_set_active(port, 1); |
36c621d8 AC |
487 | return 0; |
488 | } | |
489 | ||
490 | if (C_CLOCAL(tty)) | |
491 | do_clocal = 1; | |
492 | ||
493 | /* Block waiting until we can proceed. We may need to wait for the | |
494 | carrier, but we must also wait for any close that is in progress | |
495 | before the next open may complete */ | |
496 | ||
497 | retval = 0; | |
36c621d8 AC |
498 | |
499 | /* The port lock protects the port counts */ | |
500 | spin_lock_irqsave(&port->lock, flags); | |
e359a4e3 | 501 | port->count--; |
36c621d8 AC |
502 | port->blocked_open++; |
503 | spin_unlock_irqrestore(&port->lock, flags); | |
504 | ||
505 | while (1) { | |
506 | /* Indicate we are open */ | |
d41861ca | 507 | if (C_BAUD(tty) && tty_port_initialized(port)) |
7834909f | 508 | tty_port_raise_dtr_rts(port); |
36c621d8 | 509 | |
3e3b5c08 | 510 | prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE); |
d774a56d AC |
511 | /* Check for a hangup or uninitialised port. |
512 | Return accordingly */ | |
d41861ca | 513 | if (tty_hung_up_p(filp) || !tty_port_initialized(port)) { |
36c621d8 AC |
514 | if (port->flags & ASYNC_HUP_NOTIFY) |
515 | retval = -EAGAIN; | |
516 | else | |
517 | retval = -ERESTARTSYS; | |
518 | break; | |
519 | } | |
0eee50af JS |
520 | /* |
521 | * Probe the carrier. For devices with no carrier detect | |
522 | * tty_port_carrier_raised will always return true. | |
523 | * Never ask drivers if CLOCAL is set, this causes troubles | |
524 | * on some hardware. | |
525 | */ | |
fef062cb | 526 | if (do_clocal || tty_port_carrier_raised(port)) |
36c621d8 AC |
527 | break; |
528 | if (signal_pending(current)) { | |
529 | retval = -ERESTARTSYS; | |
530 | break; | |
531 | } | |
89c8d91e | 532 | tty_unlock(tty); |
36c621d8 | 533 | schedule(); |
89c8d91e | 534 | tty_lock(tty); |
36c621d8 | 535 | } |
3e3b5c08 | 536 | finish_wait(&port->open_wait, &wait); |
36c621d8 AC |
537 | |
538 | /* Update counts. A parallel hangup will have set count to zero and | |
539 | we must not mess that up further */ | |
540 | spin_lock_irqsave(&port->lock, flags); | |
541 | if (!tty_hung_up_p(filp)) | |
542 | port->count++; | |
543 | port->blocked_open--; | |
36c621d8 | 544 | spin_unlock_irqrestore(&port->lock, flags); |
807c8d81 PH |
545 | if (retval == 0) |
546 | tty_port_set_active(port, 1); | |
ecc2e05e | 547 | return retval; |
36c621d8 AC |
548 | } |
549 | EXPORT_SYMBOL(tty_port_block_til_ready); | |
550 | ||
b74414f5 JH |
551 | static void tty_port_drain_delay(struct tty_port *port, struct tty_struct *tty) |
552 | { | |
553 | unsigned int bps = tty_get_baud_rate(tty); | |
554 | long timeout; | |
555 | ||
556 | if (bps > 1200) { | |
557 | timeout = (HZ * 10 * port->drain_delay) / bps; | |
558 | timeout = max_t(long, timeout, HZ / 10); | |
559 | } else { | |
560 | timeout = 2 * HZ; | |
561 | } | |
562 | schedule_timeout_interruptible(timeout); | |
563 | } | |
564 | ||
79c1faa4 | 565 | /* Caller holds tty lock. */ |
d774a56d AC |
566 | int tty_port_close_start(struct tty_port *port, |
567 | struct tty_struct *tty, struct file *filp) | |
a6614999 AC |
568 | { |
569 | unsigned long flags; | |
570 | ||
633caba8 | 571 | if (tty_hung_up_p(filp)) |
a6614999 | 572 | return 0; |
a6614999 | 573 | |
633caba8 | 574 | spin_lock_irqsave(&port->lock, flags); |
d774a56d | 575 | if (tty->count == 1 && port->count != 1) { |
339f36ba PH |
576 | tty_warn(tty, "%s: tty->count = 1 port count = %d\n", __func__, |
577 | port->count); | |
a6614999 AC |
578 | port->count = 1; |
579 | } | |
580 | if (--port->count < 0) { | |
339f36ba PH |
581 | tty_warn(tty, "%s: bad port count (%d)\n", __func__, |
582 | port->count); | |
a6614999 AC |
583 | port->count = 0; |
584 | } | |
585 | ||
586 | if (port->count) { | |
587 | spin_unlock_irqrestore(&port->lock, flags); | |
588 | return 0; | |
589 | } | |
a6614999 | 590 | spin_unlock_irqrestore(&port->lock, flags); |
0b2588ca | 591 | |
ddc7b758 PH |
592 | tty->closing = 1; |
593 | ||
d41861ca | 594 | if (tty_port_initialized(port)) { |
0b2588ca JH |
595 | /* Don't block on a stalled port, just pull the chain */ |
596 | if (tty->flow_stopped) | |
597 | tty_driver_flush_buffer(tty); | |
598 | if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE) | |
79c1faa4 | 599 | tty_wait_until_sent(tty, port->closing_wait); |
0b2588ca JH |
600 | if (port->drain_delay) |
601 | tty_port_drain_delay(port, tty); | |
602 | } | |
e707c35c AC |
603 | /* Flush the ldisc buffering */ |
604 | tty_ldisc_flush(tty); | |
605 | ||
469d6d06 | 606 | /* Report to caller this is the last port reference */ |
a6614999 AC |
607 | return 1; |
608 | } | |
609 | EXPORT_SYMBOL(tty_port_close_start); | |
610 | ||
0733db91 | 611 | /* Caller holds tty lock */ |
a6614999 AC |
612 | void tty_port_close_end(struct tty_port *port, struct tty_struct *tty) |
613 | { | |
614 | unsigned long flags; | |
615 | ||
3f40f5b2 | 616 | tty_ldisc_flush(tty); |
a6614999 AC |
617 | tty->closing = 0; |
618 | ||
ddc7b758 PH |
619 | spin_lock_irqsave(&port->lock, flags); |
620 | ||
a6614999 AC |
621 | if (port->blocked_open) { |
622 | spin_unlock_irqrestore(&port->lock, flags); | |
5823323e PH |
623 | if (port->close_delay) |
624 | msleep_interruptible(jiffies_to_msecs(port->close_delay)); | |
a6614999 AC |
625 | spin_lock_irqsave(&port->lock, flags); |
626 | wake_up_interruptible(&port->open_wait); | |
627 | } | |
a6614999 | 628 | spin_unlock_irqrestore(&port->lock, flags); |
807c8d81 | 629 | tty_port_set_active(port, 0); |
a6614999 AC |
630 | } |
631 | EXPORT_SYMBOL(tty_port_close_end); | |
7ca0ff9a | 632 | |
0733db91 PH |
633 | /** |
634 | * tty_port_close | |
635 | * | |
636 | * Caller holds tty lock | |
0733db91 | 637 | */ |
7ca0ff9a AC |
638 | void tty_port_close(struct tty_port *port, struct tty_struct *tty, |
639 | struct file *filp) | |
640 | { | |
641 | if (tty_port_close_start(port, tty, filp) == 0) | |
642 | return; | |
957dacae | 643 | tty_port_shutdown(port, tty); |
d74e8286 | 644 | set_bit(TTY_IO_ERROR, &tty->flags); |
7ca0ff9a AC |
645 | tty_port_close_end(port, tty); |
646 | tty_port_tty_set(port, NULL); | |
647 | } | |
648 | EXPORT_SYMBOL(tty_port_close); | |
64bc3979 | 649 | |
72a33bf5 JS |
650 | /** |
651 | * tty_port_install - generic tty->ops->install handler | |
652 | * @port: tty_port of the device | |
653 | * @driver: tty_driver for this device | |
654 | * @tty: tty to be installed | |
655 | * | |
656 | * It is the same as tty_standard_install except the provided @port is linked | |
657 | * to a concrete tty specified by @tty. Use this or tty_port_register_device | |
658 | * (or both). Call tty_port_link_device as a last resort. | |
659 | */ | |
695586ca JS |
660 | int tty_port_install(struct tty_port *port, struct tty_driver *driver, |
661 | struct tty_struct *tty) | |
662 | { | |
663 | tty->port = port; | |
664 | return tty_standard_install(driver, tty); | |
665 | } | |
666 | EXPORT_SYMBOL_GPL(tty_port_install); | |
667 | ||
addd4672 PH |
668 | /** |
669 | * tty_port_open | |
670 | * | |
671 | * Caller holds tty lock. | |
672 | * | |
673 | * NB: may drop and reacquire tty lock (in tty_port_block_til_ready()) so | |
674 | * tty and tty_port may have changed state (eg., may be hung up now) | |
675 | */ | |
64bc3979 | 676 | int tty_port_open(struct tty_port *port, struct tty_struct *tty, |
d774a56d | 677 | struct file *filp) |
64bc3979 AC |
678 | { |
679 | spin_lock_irq(&port->lock); | |
e359a4e3 | 680 | ++port->count; |
64bc3979 AC |
681 | spin_unlock_irq(&port->lock); |
682 | tty_port_tty_set(port, tty); | |
683 | ||
684 | /* | |
685 | * Do the device-specific open only if the hardware isn't | |
686 | * already initialized. Serialize open and shutdown using the | |
687 | * port mutex. | |
688 | */ | |
689 | ||
690 | mutex_lock(&port->mutex); | |
691 | ||
d41861ca | 692 | if (!tty_port_initialized(port)) { |
a9a37ec3 | 693 | clear_bit(TTY_IO_ERROR, &tty->flags); |
64bc3979 AC |
694 | if (port->ops->activate) { |
695 | int retval = port->ops->activate(port, tty); | |
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 | } | |
706 | ||
707 | EXPORT_SYMBOL(tty_port_open); |