Commit | Line | Data |
---|---|---|
e0495736 AC |
1 | /* |
2 | * Tty buffer allocation management | |
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> | |
10 | #include <linux/timer.h> | |
11 | #include <linux/string.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/wait.h> | |
16 | #include <linux/bitops.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/module.h> | |
593fb1ae | 19 | #include <linux/ratelimit.h> |
e0495736 | 20 | |
1cef50e3 PH |
21 | |
22 | #define MIN_TTYB_SIZE 256 | |
23 | #define TTYB_ALIGN_MASK 255 | |
24 | ||
7bfe0b71 PH |
25 | /* |
26 | * Byte threshold to limit memory consumption for flip buffers. | |
27 | * The actual memory limit is > 2x this amount. | |
28 | */ | |
29 | #define TTYB_MEM_LIMIT 65536 | |
30 | ||
9114fe8c PH |
31 | /* |
32 | * We default to dicing tty buffer allocations to this many characters | |
33 | * in order to avoid multiple page allocations. We know the size of | |
34 | * tty_buffer itself but it must also be taken into account that the | |
35 | * the buffer is 256 byte aligned. See tty_buffer_find for the allocation | |
36 | * logic this must match | |
37 | */ | |
38 | ||
39 | #define TTY_BUFFER_PAGE (((PAGE_SIZE - sizeof(struct tty_buffer)) / 2) & ~0xFF) | |
40 | ||
7bfe0b71 | 41 | |
a7c8d58c PH |
42 | /** |
43 | * tty_buffer_lock_exclusive - gain exclusive access to buffer | |
44 | * tty_buffer_unlock_exclusive - release exclusive access | |
45 | * | |
46 | * @port - tty_port owning the flip buffer | |
47 | * | |
48 | * Guarantees safe use of the line discipline's receive_buf() method by | |
49 | * excluding the buffer work and any pending flush from using the flip | |
50 | * buffer. Data can continue to be added concurrently to the flip buffer | |
51 | * from the driver side. | |
52 | * | |
53 | * On release, the buffer work is restarted if there is data in the | |
54 | * flip buffer | |
55 | */ | |
56 | ||
57 | void tty_buffer_lock_exclusive(struct tty_port *port) | |
58 | { | |
59 | struct tty_bufhead *buf = &port->buf; | |
60 | ||
61 | atomic_inc(&buf->priority); | |
62 | mutex_lock(&buf->lock); | |
63 | } | |
64 | ||
65 | void tty_buffer_unlock_exclusive(struct tty_port *port) | |
66 | { | |
67 | struct tty_bufhead *buf = &port->buf; | |
68 | int restart; | |
69 | ||
70 | restart = buf->head->commit != buf->head->read; | |
71 | ||
72 | atomic_dec(&buf->priority); | |
73 | mutex_unlock(&buf->lock); | |
74 | if (restart) | |
75 | queue_work(system_unbound_wq, &buf->work); | |
76 | } | |
77 | ||
7bfe0b71 PH |
78 | /** |
79 | * tty_buffer_space_avail - return unused buffer space | |
80 | * @port - tty_port owning the flip buffer | |
81 | * | |
82 | * Returns the # of bytes which can be written by the driver without | |
83 | * reaching the buffer limit. | |
84 | * | |
85 | * Note: this does not guarantee that memory is available to write | |
86 | * the returned # of bytes (use tty_prepare_flip_string_xxx() to | |
87 | * pre-allocate if memory guarantee is required). | |
88 | */ | |
89 | ||
90 | int tty_buffer_space_avail(struct tty_port *port) | |
91 | { | |
92 | int space = TTYB_MEM_LIMIT - atomic_read(&port->buf.memory_used); | |
93 | return max(space, 0); | |
94 | } | |
95 | ||
9dd5139f PH |
96 | static void tty_buffer_reset(struct tty_buffer *p, size_t size) |
97 | { | |
98 | p->used = 0; | |
99 | p->size = size; | |
100 | p->next = NULL; | |
101 | p->commit = 0; | |
102 | p->read = 0; | |
103 | } | |
104 | ||
e0495736 AC |
105 | /** |
106 | * tty_buffer_free_all - free buffers used by a tty | |
107 | * @tty: tty to free from | |
108 | * | |
109 | * Remove all the buffers pending on a tty whether queued with data | |
110 | * or in the free ring. Must be called when the tty is no longer in use | |
e0495736 AC |
111 | */ |
112 | ||
ecbbfd44 | 113 | void tty_buffer_free_all(struct tty_port *port) |
e0495736 | 114 | { |
ecbbfd44 | 115 | struct tty_bufhead *buf = &port->buf; |
809850b7 PH |
116 | struct tty_buffer *p, *next; |
117 | struct llist_node *llist; | |
5cff39c6 | 118 | |
2cf7b67e PH |
119 | while ((p = buf->head) != NULL) { |
120 | buf->head = p->next; | |
7391ee16 PH |
121 | if (p->size > 0) |
122 | kfree(p); | |
e0495736 | 123 | } |
809850b7 PH |
124 | llist = llist_del_all(&buf->free); |
125 | llist_for_each_entry_safe(p, next, llist, free) | |
2cf7b67e | 126 | kfree(p); |
809850b7 | 127 | |
7391ee16 PH |
128 | tty_buffer_reset(&buf->sentinel, 0); |
129 | buf->head = &buf->sentinel; | |
130 | buf->tail = &buf->sentinel; | |
7bfe0b71 PH |
131 | |
132 | atomic_set(&buf->memory_used, 0); | |
e0495736 AC |
133 | } |
134 | ||
135 | /** | |
136 | * tty_buffer_alloc - allocate a tty buffer | |
137 | * @tty: tty device | |
138 | * @size: desired size (characters) | |
139 | * | |
140 | * Allocate a new tty buffer to hold the desired number of characters. | |
11b9faa4 PH |
141 | * We round our buffers off in 256 character chunks to get better |
142 | * allocation behaviour. | |
e0495736 AC |
143 | * Return NULL if out of memory or the allocation would exceed the |
144 | * per device queue | |
e0495736 AC |
145 | */ |
146 | ||
ecbbfd44 | 147 | static struct tty_buffer *tty_buffer_alloc(struct tty_port *port, size_t size) |
e0495736 | 148 | { |
809850b7 | 149 | struct llist_node *free; |
e0495736 AC |
150 | struct tty_buffer *p; |
151 | ||
11b9faa4 PH |
152 | /* Round the buffer size out */ |
153 | size = __ALIGN_MASK(size, TTYB_ALIGN_MASK); | |
154 | ||
155 | if (size <= MIN_TTYB_SIZE) { | |
809850b7 PH |
156 | free = llist_del_first(&port->buf.free); |
157 | if (free) { | |
158 | p = llist_entry(free, struct tty_buffer, free); | |
11b9faa4 PH |
159 | goto found; |
160 | } | |
161 | } | |
162 | ||
163 | /* Should possibly check if this fails for the largest buffer we | |
164 | have queued and recycle that ? */ | |
7bfe0b71 | 165 | if (atomic_read(&port->buf.memory_used) > TTYB_MEM_LIMIT) |
e0495736 AC |
166 | return NULL; |
167 | p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC); | |
168 | if (p == NULL) | |
169 | return NULL; | |
9dd5139f | 170 | |
11b9faa4 | 171 | found: |
9dd5139f | 172 | tty_buffer_reset(p, size); |
7bfe0b71 | 173 | atomic_add(size, &port->buf.memory_used); |
e0495736 AC |
174 | return p; |
175 | } | |
176 | ||
177 | /** | |
178 | * tty_buffer_free - free a tty buffer | |
179 | * @tty: tty owning the buffer | |
180 | * @b: the buffer to free | |
181 | * | |
182 | * Free a tty buffer, or add it to the free list according to our | |
183 | * internal strategy | |
e0495736 AC |
184 | */ |
185 | ||
ecbbfd44 | 186 | static void tty_buffer_free(struct tty_port *port, struct tty_buffer *b) |
e0495736 | 187 | { |
ecbbfd44 | 188 | struct tty_bufhead *buf = &port->buf; |
5cff39c6 | 189 | |
e0495736 | 190 | /* Dumb strategy for now - should keep some stats */ |
7bfe0b71 | 191 | WARN_ON(atomic_sub_return(b->size, &buf->memory_used) < 0); |
e0495736 | 192 | |
1cef50e3 | 193 | if (b->size > MIN_TTYB_SIZE) |
e0495736 | 194 | kfree(b); |
7391ee16 | 195 | else if (b->size > 0) |
809850b7 | 196 | llist_add(&b->free, &buf->free); |
e0495736 AC |
197 | } |
198 | ||
e0495736 AC |
199 | /** |
200 | * tty_buffer_flush - flush full tty buffers | |
201 | * @tty: tty to flush | |
202 | * | |
203 | * flush all the buffers containing receive data. If the buffer is | |
204 | * being processed by flush_to_ldisc then we defer the processing | |
205 | * to that function | |
206 | * | |
a7c8d58c | 207 | * Locking: takes buffer lock to ensure single-threaded flip buffer |
e9975fde | 208 | * 'consumer' |
e0495736 AC |
209 | */ |
210 | ||
211 | void tty_buffer_flush(struct tty_struct *tty) | |
212 | { | |
2fc20661 | 213 | struct tty_port *port = tty->port; |
ecbbfd44 | 214 | struct tty_bufhead *buf = &port->buf; |
47aa658a | 215 | struct tty_buffer *next; |
e0495736 | 216 | |
a7c8d58c | 217 | atomic_inc(&buf->priority); |
e9975fde | 218 | |
a7c8d58c | 219 | mutex_lock(&buf->lock); |
47aa658a PH |
220 | while ((next = buf->head->next) != NULL) { |
221 | tty_buffer_free(port, buf->head); | |
222 | buf->head = next; | |
223 | } | |
224 | buf->head->read = buf->head->commit; | |
a7c8d58c PH |
225 | atomic_dec(&buf->priority); |
226 | mutex_unlock(&buf->lock); | |
e0495736 AC |
227 | } |
228 | ||
e0495736 | 229 | /** |
64325a3b | 230 | * tty_buffer_request_room - grow tty buffer if needed |
e0495736 AC |
231 | * @tty: tty structure |
232 | * @size: size desired | |
233 | * | |
234 | * Make at least size bytes of linear space available for the tty | |
235 | * buffer. If we fail return the size we managed to find. | |
e0495736 | 236 | */ |
64325a3b | 237 | int tty_buffer_request_room(struct tty_port *port, size_t size) |
e0495736 | 238 | { |
ecbbfd44 | 239 | struct tty_bufhead *buf = &port->buf; |
e0495736 AC |
240 | struct tty_buffer *b, *n; |
241 | int left; | |
e8437d7e | 242 | |
5cff39c6 | 243 | b = buf->tail; |
7391ee16 | 244 | left = b->size - b->used; |
e0495736 AC |
245 | |
246 | if (left < size) { | |
247 | /* This is the slow path - looking for new buffers to use */ | |
11b9faa4 | 248 | if ((n = tty_buffer_alloc(port, size)) != NULL) { |
5cff39c6 | 249 | buf->tail = n; |
e8437d7e PH |
250 | b->commit = b->used; |
251 | smp_mb(); | |
252 | b->next = n; | |
e0495736 AC |
253 | } else |
254 | size = left; | |
255 | } | |
e0495736 AC |
256 | return size; |
257 | } | |
258 | EXPORT_SYMBOL_GPL(tty_buffer_request_room); | |
259 | ||
260 | /** | |
2832fc11 | 261 | * tty_insert_flip_string_fixed_flag - Add characters to the tty buffer |
2f693357 | 262 | * @port: tty port |
e0495736 | 263 | * @chars: characters |
2832fc11 | 264 | * @flag: flag value for each character |
e0495736 AC |
265 | * @size: size |
266 | * | |
267 | * Queue a series of bytes to the tty buffering. All the characters | |
ccc5ca8d | 268 | * passed are marked with the supplied flag. Returns the number added. |
e0495736 AC |
269 | */ |
270 | ||
2f693357 | 271 | int tty_insert_flip_string_fixed_flag(struct tty_port *port, |
2832fc11 | 272 | const unsigned char *chars, char flag, size_t size) |
e0495736 AC |
273 | { |
274 | int copied = 0; | |
275 | do { | |
d4bee0a6 | 276 | int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE); |
64325a3b IZ |
277 | int space = tty_buffer_request_room(port, goal); |
278 | struct tty_buffer *tb = port->buf.tail; | |
7391ee16 | 279 | if (unlikely(space == 0)) |
e0495736 | 280 | break; |
1fc359fc PH |
281 | memcpy(char_buf_ptr(tb, tb->used), chars, space); |
282 | memset(flag_buf_ptr(tb, tb->used), flag, space); | |
e0495736 AC |
283 | tb->used += space; |
284 | copied += space; | |
285 | chars += space; | |
286 | /* There is a small chance that we need to split the data over | |
287 | several buffers. If this is the case we must loop */ | |
288 | } while (unlikely(size > copied)); | |
289 | return copied; | |
290 | } | |
2832fc11 | 291 | EXPORT_SYMBOL(tty_insert_flip_string_fixed_flag); |
e0495736 AC |
292 | |
293 | /** | |
294 | * tty_insert_flip_string_flags - Add characters to the tty buffer | |
2f693357 | 295 | * @port: tty port |
e0495736 AC |
296 | * @chars: characters |
297 | * @flags: flag bytes | |
298 | * @size: size | |
299 | * | |
300 | * Queue a series of bytes to the tty buffering. For each character | |
301 | * the flags array indicates the status of the character. Returns the | |
302 | * number added. | |
e0495736 AC |
303 | */ |
304 | ||
2f693357 | 305 | int tty_insert_flip_string_flags(struct tty_port *port, |
e0495736 AC |
306 | const unsigned char *chars, const char *flags, size_t size) |
307 | { | |
308 | int copied = 0; | |
309 | do { | |
d4bee0a6 | 310 | int goal = min_t(size_t, size - copied, TTY_BUFFER_PAGE); |
64325a3b IZ |
311 | int space = tty_buffer_request_room(port, goal); |
312 | struct tty_buffer *tb = port->buf.tail; | |
7391ee16 | 313 | if (unlikely(space == 0)) |
e0495736 | 314 | break; |
1fc359fc PH |
315 | memcpy(char_buf_ptr(tb, tb->used), chars, space); |
316 | memcpy(flag_buf_ptr(tb, tb->used), flags, space); | |
e0495736 AC |
317 | tb->used += space; |
318 | copied += space; | |
319 | chars += space; | |
320 | flags += space; | |
321 | /* There is a small chance that we need to split the data over | |
322 | several buffers. If this is the case we must loop */ | |
323 | } while (unlikely(size > copied)); | |
324 | return copied; | |
325 | } | |
326 | EXPORT_SYMBOL(tty_insert_flip_string_flags); | |
327 | ||
328 | /** | |
329 | * tty_schedule_flip - push characters to ldisc | |
6732c8bb | 330 | * @port: tty port to push from |
e0495736 AC |
331 | * |
332 | * Takes any pending buffers and transfers their ownership to the | |
333 | * ldisc side of the queue. It then schedules those characters for | |
334 | * processing by the line discipline. | |
cee4ad1e IS |
335 | * Note that this function can only be used when the low_latency flag |
336 | * is unset. Otherwise the workqueue won't be flushed. | |
e0495736 AC |
337 | */ |
338 | ||
6732c8bb | 339 | void tty_schedule_flip(struct tty_port *port) |
e0495736 | 340 | { |
6732c8bb | 341 | struct tty_bufhead *buf = &port->buf; |
6732c8bb | 342 | WARN_ON(port->low_latency); |
5cff39c6 | 343 | |
7391ee16 | 344 | buf->tail->commit = buf->tail->used; |
5cff39c6 | 345 | schedule_work(&buf->work); |
e0495736 AC |
346 | } |
347 | EXPORT_SYMBOL(tty_schedule_flip); | |
348 | ||
349 | /** | |
350 | * tty_prepare_flip_string - make room for characters | |
2f693357 | 351 | * @port: tty port |
e0495736 AC |
352 | * @chars: return pointer for character write area |
353 | * @size: desired size | |
354 | * | |
355 | * Prepare a block of space in the buffer for data. Returns the length | |
356 | * available and buffer pointer to the space which is now allocated and | |
357 | * accounted for as ready for normal characters. This is used for drivers | |
358 | * that need their own block copy routines into the buffer. There is no | |
359 | * guarantee the buffer is a DMA target! | |
e0495736 AC |
360 | */ |
361 | ||
2f693357 | 362 | int tty_prepare_flip_string(struct tty_port *port, unsigned char **chars, |
ecbbfd44 | 363 | size_t size) |
e0495736 | 364 | { |
64325a3b | 365 | int space = tty_buffer_request_room(port, size); |
e0495736 | 366 | if (likely(space)) { |
64325a3b | 367 | struct tty_buffer *tb = port->buf.tail; |
1fc359fc PH |
368 | *chars = char_buf_ptr(tb, tb->used); |
369 | memset(flag_buf_ptr(tb, tb->used), TTY_NORMAL, space); | |
e0495736 AC |
370 | tb->used += space; |
371 | } | |
372 | return space; | |
373 | } | |
374 | EXPORT_SYMBOL_GPL(tty_prepare_flip_string); | |
375 | ||
376 | /** | |
377 | * tty_prepare_flip_string_flags - make room for characters | |
2f693357 | 378 | * @port: tty port |
e0495736 AC |
379 | * @chars: return pointer for character write area |
380 | * @flags: return pointer for status flag write area | |
381 | * @size: desired size | |
382 | * | |
383 | * Prepare a block of space in the buffer for data. Returns the length | |
384 | * available and buffer pointer to the space which is now allocated and | |
385 | * accounted for as ready for characters. This is used for drivers | |
386 | * that need their own block copy routines into the buffer. There is no | |
387 | * guarantee the buffer is a DMA target! | |
e0495736 AC |
388 | */ |
389 | ||
2f693357 | 390 | int tty_prepare_flip_string_flags(struct tty_port *port, |
e0495736 AC |
391 | unsigned char **chars, char **flags, size_t size) |
392 | { | |
64325a3b | 393 | int space = tty_buffer_request_room(port, size); |
e0495736 | 394 | if (likely(space)) { |
64325a3b | 395 | struct tty_buffer *tb = port->buf.tail; |
1fc359fc PH |
396 | *chars = char_buf_ptr(tb, tb->used); |
397 | *flags = flag_buf_ptr(tb, tb->used); | |
e0495736 AC |
398 | tb->used += space; |
399 | } | |
400 | return space; | |
401 | } | |
402 | EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags); | |
403 | ||
404 | ||
da261e7f PH |
405 | static int |
406 | receive_buf(struct tty_struct *tty, struct tty_buffer *head, int count) | |
407 | { | |
408 | struct tty_ldisc *disc = tty->ldisc; | |
1fc359fc PH |
409 | unsigned char *p = char_buf_ptr(head, head->read); |
410 | char *f = flag_buf_ptr(head, head->read); | |
da261e7f | 411 | |
24a89d1c PH |
412 | if (disc->ops->receive_buf2) |
413 | count = disc->ops->receive_buf2(tty, p, f, count); | |
414 | else { | |
415 | count = min_t(int, count, tty->receive_room); | |
416 | if (count) | |
417 | disc->ops->receive_buf(tty, p, f, count); | |
418 | } | |
da261e7f PH |
419 | head->read += count; |
420 | return count; | |
421 | } | |
e0495736 AC |
422 | |
423 | /** | |
424 | * flush_to_ldisc | |
425 | * @work: tty structure passed from work queue. | |
426 | * | |
427 | * This routine is called out of the software interrupt to flush data | |
428 | * from the buffer chain to the line discipline. | |
429 | * | |
e9975fde PH |
430 | * The receive_buf method is single threaded for each tty instance. |
431 | * | |
a7c8d58c | 432 | * Locking: takes buffer lock to ensure single-threaded flip buffer |
e9975fde | 433 | * 'consumer' |
e0495736 AC |
434 | */ |
435 | ||
436 | static void flush_to_ldisc(struct work_struct *work) | |
437 | { | |
ecbbfd44 JS |
438 | struct tty_port *port = container_of(work, struct tty_port, buf.work); |
439 | struct tty_bufhead *buf = &port->buf; | |
440 | struct tty_struct *tty; | |
e0495736 | 441 | struct tty_ldisc *disc; |
e0495736 | 442 | |
ecbbfd44 | 443 | tty = port->itty; |
34dcfb84 | 444 | if (tty == NULL) |
ecbbfd44 JS |
445 | return; |
446 | ||
e0495736 | 447 | disc = tty_ldisc_ref(tty); |
36697529 | 448 | if (disc == NULL) |
e0495736 AC |
449 | return; |
450 | ||
a7c8d58c | 451 | mutex_lock(&buf->lock); |
45242006 | 452 | |
d7a68be4 PH |
453 | while (1) { |
454 | struct tty_buffer *head = buf->head; | |
455 | int count; | |
456 | ||
a7c8d58c PH |
457 | /* Ldisc or user is trying to gain exclusive access */ |
458 | if (atomic_read(&buf->priority)) | |
d7a68be4 PH |
459 | break; |
460 | ||
461 | count = head->commit - head->read; | |
462 | if (!count) { | |
463 | if (head->next == NULL) | |
da261e7f | 464 | break; |
d7a68be4 PH |
465 | buf->head = head->next; |
466 | tty_buffer_free(port, head); | |
467 | continue; | |
e0495736 | 468 | } |
d7a68be4 PH |
469 | |
470 | count = receive_buf(tty, head, count); | |
471 | if (!count) | |
472 | break; | |
e0495736 | 473 | } |
45242006 | 474 | |
a7c8d58c | 475 | mutex_unlock(&buf->lock); |
e0495736 AC |
476 | |
477 | tty_ldisc_deref(disc); | |
478 | } | |
479 | ||
e043e42b OH |
480 | /** |
481 | * tty_flush_to_ldisc | |
482 | * @tty: tty to push | |
483 | * | |
484 | * Push the terminal flip buffers to the line discipline. | |
485 | * | |
486 | * Must not be called from IRQ context. | |
487 | */ | |
488 | void tty_flush_to_ldisc(struct tty_struct *tty) | |
489 | { | |
d6c53c0e | 490 | if (!tty->port->low_latency) |
ecbbfd44 | 491 | flush_work(&tty->port->buf.work); |
e043e42b OH |
492 | } |
493 | ||
e0495736 AC |
494 | /** |
495 | * tty_flip_buffer_push - terminal | |
2e124b4a | 496 | * @port: tty port to push |
e0495736 AC |
497 | * |
498 | * Queue a push of the terminal flip buffers to the line discipline. This | |
d6c53c0e JS |
499 | * function must not be called from IRQ context if port->low_latency is |
500 | * set. | |
e0495736 AC |
501 | * |
502 | * In the event of the queue being busy for flipping the work will be | |
503 | * held off and retried later. | |
e0495736 AC |
504 | */ |
505 | ||
2e124b4a | 506 | void tty_flip_buffer_push(struct tty_port *port) |
e0495736 | 507 | { |
2e124b4a | 508 | struct tty_bufhead *buf = &port->buf; |
5cff39c6 | 509 | |
7391ee16 | 510 | buf->tail->commit = buf->tail->used; |
e0495736 | 511 | |
2e124b4a | 512 | if (port->low_latency) |
5cff39c6 | 513 | flush_to_ldisc(&buf->work); |
e0495736 | 514 | else |
5cff39c6 | 515 | schedule_work(&buf->work); |
e0495736 AC |
516 | } |
517 | EXPORT_SYMBOL(tty_flip_buffer_push); | |
518 | ||
519 | /** | |
520 | * tty_buffer_init - prepare a tty buffer structure | |
521 | * @tty: tty to initialise | |
522 | * | |
523 | * Set up the initial state of the buffer management for a tty device. | |
524 | * Must be called before the other tty buffer functions are used. | |
e0495736 AC |
525 | */ |
526 | ||
ecbbfd44 | 527 | void tty_buffer_init(struct tty_port *port) |
e0495736 | 528 | { |
ecbbfd44 | 529 | struct tty_bufhead *buf = &port->buf; |
5cff39c6 | 530 | |
a7c8d58c | 531 | mutex_init(&buf->lock); |
7391ee16 PH |
532 | tty_buffer_reset(&buf->sentinel, 0); |
533 | buf->head = &buf->sentinel; | |
534 | buf->tail = &buf->sentinel; | |
809850b7 | 535 | init_llist_head(&buf->free); |
7bfe0b71 | 536 | atomic_set(&buf->memory_used, 0); |
a7c8d58c | 537 | atomic_set(&buf->priority, 0); |
5cff39c6 | 538 | INIT_WORK(&buf->work, flush_to_ldisc); |
e0495736 | 539 | } |