Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM | |
3 | * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM | |
4 | * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp. | |
5 | * Copyright (C) 2004 IBM Corporation | |
6 | * | |
7 | * Additional Author(s): | |
8 | * Ryan S. Arnold <rsa@us.ibm.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License as published by | |
12 | * the Free Software Foundation; either version 2 of the License, or | |
13 | * (at your option) any later version. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, | |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | * GNU General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program; if not, write to the Free Software | |
22 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
23 | */ | |
24 | ||
25 | #include <linux/console.h> | |
26 | #include <linux/cpumask.h> | |
27 | #include <linux/init.h> | |
28 | #include <linux/kbd_kern.h> | |
29 | #include <linux/kernel.h> | |
1da177e4 LT |
30 | #include <linux/kthread.h> |
31 | #include <linux/list.h> | |
32 | #include <linux/module.h> | |
33 | #include <linux/major.h> | |
34 | #include <linux/sysrq.h> | |
35 | #include <linux/tty.h> | |
36 | #include <linux/tty_flip.h> | |
37 | #include <linux/sched.h> | |
38 | #include <linux/spinlock.h> | |
39 | #include <linux/delay.h> | |
7dfb7103 | 40 | #include <linux/freezer.h> |
5a0e3ad6 | 41 | #include <linux/slab.h> |
762e77ae | 42 | #include <linux/serial_core.h> |
45d607ed | 43 | |
1da177e4 | 44 | #include <asm/uaccess.h> |
45d607ed RA |
45 | |
46 | #include "hvc_console.h" | |
1da177e4 LT |
47 | |
48 | #define HVC_MAJOR 229 | |
49 | #define HVC_MINOR 0 | |
50 | ||
1da177e4 LT |
51 | /* |
52 | * Wait this long per iteration while trying to push buffered data to the | |
53 | * hypervisor before allowing the tty to complete a close operation. | |
54 | */ | |
55 | #define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */ | |
56 | ||
57 | /* | |
45d607ed RA |
58 | * These sizes are most efficient for vio, because they are the |
59 | * native transfer size. We could make them selectable in the | |
60 | * future to better deal with backends that want other buffer sizes. | |
1da177e4 | 61 | */ |
1da177e4 LT |
62 | #define N_OUTBUF 16 |
63 | #define N_INBUF 16 | |
64 | ||
45d607ed | 65 | #define __ALIGNED__ __attribute__((__aligned__(sizeof(long)))) |
1da177e4 | 66 | |
837dcfaf MM |
67 | static struct tty_driver *hvc_driver; |
68 | static struct task_struct *hvc_task; | |
69 | ||
70 | /* Picks up late kicks after list walk but before schedule() */ | |
71 | static int hvc_kicked; | |
72 | ||
3e6c6f63 RR |
73 | static int hvc_init(void); |
74 | ||
837dcfaf MM |
75 | #ifdef CONFIG_MAGIC_SYSRQ |
76 | static int sysrq_pressed; | |
77 | #endif | |
78 | ||
1da177e4 | 79 | /* dynamic list of hvc_struct instances */ |
bed9759b | 80 | static LIST_HEAD(hvc_structs); |
1da177e4 LT |
81 | |
82 | /* | |
83 | * Protect the list of hvc_struct instances from inserts and removals during | |
84 | * list traversal. | |
85 | */ | |
86 | static DEFINE_SPINLOCK(hvc_structs_lock); | |
87 | ||
837dcfaf | 88 | /* |
6f24808e MM |
89 | * This value is used to assign a tty->index value to a hvc_struct based |
90 | * upon order of exposure via hvc_probe(), when we can not match it to | |
c3ea6921 | 91 | * a console candidate registered with hvc_instantiate(). |
837dcfaf | 92 | */ |
6f24808e | 93 | static int last_hvc = -1; |
837dcfaf MM |
94 | |
95 | /* | |
c3ea6921 | 96 | * Do not call this function with either the hvc_structs_lock or the hvc_struct |
12b20ded | 97 | * lock held. If successful, this function increments the kref reference |
837dcfaf MM |
98 | * count against the target hvc_struct so it should be released when finished. |
99 | */ | |
4fa156ea | 100 | static struct hvc_struct *hvc_get_by_index(int index) |
837dcfaf MM |
101 | { |
102 | struct hvc_struct *hp; | |
103 | unsigned long flags; | |
104 | ||
105 | spin_lock(&hvc_structs_lock); | |
106 | ||
107 | list_for_each_entry(hp, &hvc_structs, next) { | |
108 | spin_lock_irqsave(&hp->lock, flags); | |
109 | if (hp->index == index) { | |
f3d9f250 | 110 | tty_port_get(&hp->port); |
837dcfaf MM |
111 | spin_unlock_irqrestore(&hp->lock, flags); |
112 | spin_unlock(&hvc_structs_lock); | |
113 | return hp; | |
114 | } | |
115 | spin_unlock_irqrestore(&hp->lock, flags); | |
116 | } | |
117 | hp = NULL; | |
118 | ||
119 | spin_unlock(&hvc_structs_lock); | |
120 | return hp; | |
121 | } | |
122 | ||
123 | ||
1da177e4 LT |
124 | /* |
125 | * Initial console vtermnos for console API usage prior to full console | |
126 | * initialization. Any vty adapter outside this range will not have usable | |
127 | * console interfaces but can still be used as a tty device. This has to be | |
128 | * static because kmalloc will not work during early console init. | |
129 | */ | |
b5113068 | 130 | static const struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; |
64e4da57 MM |
131 | static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] = |
132 | {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1}; | |
1da177e4 | 133 | |
837dcfaf MM |
134 | /* |
135 | * Console APIs, NOT TTY. These APIs are available immediately when | |
136 | * hvc_console_setup() finds adapters. | |
137 | */ | |
138 | ||
4fa156ea AB |
139 | static void hvc_console_print(struct console *co, const char *b, |
140 | unsigned count) | |
837dcfaf | 141 | { |
45d607ed | 142 | char c[N_OUTBUF] __ALIGNED__; |
837dcfaf | 143 | unsigned i = 0, n = 0; |
030ffad2 | 144 | int r, donecr = 0, index = co->index; |
837dcfaf MM |
145 | |
146 | /* Console access attempt outside of acceptable console range. */ | |
030ffad2 | 147 | if (index >= MAX_NR_HVC_CONSOLES) |
837dcfaf MM |
148 | return; |
149 | ||
c3ea6921 | 150 | /* This console adapter was removed so it is not usable. */ |
ecfcbee7 | 151 | if (vtermnos[index] == -1) |
837dcfaf MM |
152 | return; |
153 | ||
154 | while (count > 0 || i > 0) { | |
155 | if (count > 0 && i < sizeof(c)) { | |
156 | if (b[n] == '\n' && !donecr) { | |
157 | c[i++] = '\r'; | |
158 | donecr = 1; | |
159 | } else { | |
160 | c[i++] = b[n++]; | |
161 | donecr = 0; | |
162 | --count; | |
163 | } | |
164 | } else { | |
030ffad2 | 165 | r = cons_ops[index]->put_chars(vtermnos[index], c, i); |
3feebbb5 | 166 | if (r <= 0) { |
8c2381af HB |
167 | /* throw away characters on error |
168 | * but spin in case of -EAGAIN */ | |
169 | if (r != -EAGAIN) | |
170 | i = 0; | |
837dcfaf MM |
171 | } else if (r > 0) { |
172 | i -= r; | |
173 | if (i > 0) | |
174 | memmove(c, c+r, i); | |
175 | } | |
176 | } | |
177 | } | |
178 | } | |
179 | ||
180 | static struct tty_driver *hvc_console_device(struct console *c, int *index) | |
181 | { | |
7805b1b2 MM |
182 | if (vtermnos[c->index] == -1) |
183 | return NULL; | |
184 | ||
837dcfaf MM |
185 | *index = c->index; |
186 | return hvc_driver; | |
187 | } | |
188 | ||
189 | static int __init hvc_console_setup(struct console *co, char *options) | |
4d2bb3f5 | 190 | { |
7805b1b2 MM |
191 | if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES) |
192 | return -ENODEV; | |
193 | ||
194 | if (vtermnos[co->index] == -1) | |
195 | return -ENODEV; | |
196 | ||
837dcfaf MM |
197 | return 0; |
198 | } | |
199 | ||
4455b119 | 200 | static struct console hvc_console = { |
837dcfaf MM |
201 | .name = "hvc", |
202 | .write = hvc_console_print, | |
203 | .device = hvc_console_device, | |
204 | .setup = hvc_console_setup, | |
205 | .flags = CON_PRINTBUFFER, | |
206 | .index = -1, | |
207 | }; | |
208 | ||
d5ee257c | 209 | /* |
c3ea6921 | 210 | * Early console initialization. Precedes driver initialization. |
d5ee257c MM |
211 | * |
212 | * (1) we are first, and the user specified another driver | |
213 | * -- index will remain -1 | |
214 | * (2) we are first and the user specified no driver | |
215 | * -- index will be set to 0, then we will fail setup. | |
216 | * (3) we are first and the user specified our driver | |
217 | * -- index will be set to user specified driver, and we will fail | |
218 | * (4) we are after driver, and this initcall will register us | |
219 | * -- if the user didn't specify a driver then the console will match | |
220 | * | |
221 | * Note that for cases 2 and 3, we will match later when the io driver | |
222 | * calls hvc_instantiate() and call register again. | |
223 | */ | |
837dcfaf MM |
224 | static int __init hvc_console_init(void) |
225 | { | |
4455b119 | 226 | register_console(&hvc_console); |
837dcfaf MM |
227 | return 0; |
228 | } | |
229 | console_initcall(hvc_console_init); | |
1da177e4 | 230 | |
12b20ded | 231 | /* callback when the kboject ref count reaches zero. */ |
f3d9f250 | 232 | static void hvc_port_destruct(struct tty_port *port) |
12b20ded | 233 | { |
f3d9f250 | 234 | struct hvc_struct *hp = container_of(port, struct hvc_struct, port); |
12b20ded GKH |
235 | unsigned long flags; |
236 | ||
237 | spin_lock(&hvc_structs_lock); | |
238 | ||
239 | spin_lock_irqsave(&hp->lock, flags); | |
240 | list_del(&(hp->next)); | |
241 | spin_unlock_irqrestore(&hp->lock, flags); | |
242 | ||
243 | spin_unlock(&hvc_structs_lock); | |
244 | ||
245 | kfree(hp); | |
246 | } | |
247 | ||
1da177e4 | 248 | /* |
6f24808e MM |
249 | * hvc_instantiate() is an early console discovery method which locates |
250 | * consoles * prior to the vio subsystem discovering them. Hotplugged | |
251 | * vty adapters do NOT get an hvc_instantiate() callback since they | |
252 | * appear after early console init. | |
1da177e4 | 253 | */ |
b5113068 | 254 | int hvc_instantiate(uint32_t vtermno, int index, const struct hv_ops *ops) |
837dcfaf | 255 | { |
7805b1b2 MM |
256 | struct hvc_struct *hp; |
257 | ||
837dcfaf MM |
258 | if (index < 0 || index >= MAX_NR_HVC_CONSOLES) |
259 | return -1; | |
1da177e4 | 260 | |
837dcfaf MM |
261 | if (vtermnos[index] != -1) |
262 | return -1; | |
263 | ||
c3ea6921 | 264 | /* make sure no no tty has been registered in this index */ |
7805b1b2 MM |
265 | hp = hvc_get_by_index(index); |
266 | if (hp) { | |
f3d9f250 | 267 | tty_port_put(&hp->port); |
7805b1b2 MM |
268 | return -1; |
269 | } | |
270 | ||
837dcfaf | 271 | vtermnos[index] = vtermno; |
030ffad2 | 272 | cons_ops[index] = ops; |
6f24808e | 273 | |
c3ea6921 | 274 | /* reserve all indices up to and including this index */ |
6f24808e MM |
275 | if (last_hvc < index) |
276 | last_hvc = index; | |
277 | ||
d5ee257c MM |
278 | /* if this index is what the user requested, then register |
279 | * now (setup won't fail at this point). It's ok to just | |
280 | * call register again if previously .setup failed. | |
281 | */ | |
4455b119 CM |
282 | if (index == hvc_console.index) |
283 | register_console(&hvc_console); | |
d5ee257c | 284 | |
837dcfaf MM |
285 | return 0; |
286 | } | |
7721c494 | 287 | EXPORT_SYMBOL_GPL(hvc_instantiate); |
1da177e4 LT |
288 | |
289 | /* Wake the sleeping khvcd */ | |
611e097d | 290 | void hvc_kick(void) |
1da177e4 LT |
291 | { |
292 | hvc_kicked = 1; | |
293 | wake_up_process(hvc_task); | |
294 | } | |
7721c494 | 295 | EXPORT_SYMBOL_GPL(hvc_kick); |
1da177e4 | 296 | |
1da177e4 LT |
297 | static void hvc_unthrottle(struct tty_struct *tty) |
298 | { | |
299 | hvc_kick(); | |
300 | } | |
301 | ||
1da177e4 LT |
302 | /* |
303 | * The TTY interface won't be used until after the vio layer has exposed the vty | |
304 | * adapter to the kernel. | |
305 | */ | |
306 | static int hvc_open(struct tty_struct *tty, struct file * filp) | |
307 | { | |
308 | struct hvc_struct *hp; | |
309 | unsigned long flags; | |
1da177e4 | 310 | int rc = 0; |
1da177e4 | 311 | |
12b20ded | 312 | /* Auto increments kref reference if found. */ |
87fd7724 | 313 | if (!(hp = hvc_get_by_index(tty->index))) |
1da177e4 | 314 | return -ENODEV; |
1da177e4 | 315 | |
0146b693 | 316 | spin_lock_irqsave(&hp->port.lock, flags); |
1da177e4 | 317 | /* Check and then increment for fast path open. */ |
0146b693 JS |
318 | if (hp->port.count++ > 0) { |
319 | spin_unlock_irqrestore(&hp->port.lock, flags); | |
1da177e4 LT |
320 | hvc_kick(); |
321 | return 0; | |
322 | } /* else count == 0 */ | |
0146b693 | 323 | spin_unlock_irqrestore(&hp->port.lock, flags); |
1da177e4 LT |
324 | |
325 | tty->driver_data = hp; | |
85bbc003 JS |
326 | tty_port_tty_set(&hp->port, tty); |
327 | ||
b1b135c8 CB |
328 | if (hp->ops->notifier_add) |
329 | rc = hp->ops->notifier_add(hp, hp->data); | |
1da177e4 LT |
330 | |
331 | /* | |
611e097d | 332 | * If the notifier fails we return an error. The tty layer |
1da177e4 LT |
333 | * will call hvc_close() after a failed open but we don't want to clean |
334 | * up there so we'll clean up here and clear out the previously set | |
12b20ded | 335 | * tty fields and return the kref reference. |
1da177e4 LT |
336 | */ |
337 | if (rc) { | |
85bbc003 | 338 | tty_port_tty_set(&hp->port, NULL); |
1da177e4 | 339 | tty->driver_data = NULL; |
f3d9f250 | 340 | tty_port_put(&hp->port); |
1da177e4 LT |
341 | printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc); |
342 | } | |
343 | /* Force wakeup of the polling thread */ | |
344 | hvc_kick(); | |
345 | ||
346 | return rc; | |
347 | } | |
348 | ||
349 | static void hvc_close(struct tty_struct *tty, struct file * filp) | |
350 | { | |
351 | struct hvc_struct *hp; | |
1da177e4 LT |
352 | unsigned long flags; |
353 | ||
354 | if (tty_hung_up_p(filp)) | |
355 | return; | |
356 | ||
357 | /* | |
358 | * No driver_data means that this close was issued after a failed | |
359 | * hvc_open by the tty layer's release_dev() function and we can just | |
12b20ded | 360 | * exit cleanly because the kref reference wasn't made. |
1da177e4 LT |
361 | */ |
362 | if (!tty->driver_data) | |
363 | return; | |
364 | ||
365 | hp = tty->driver_data; | |
e74d098c | 366 | |
0146b693 | 367 | spin_lock_irqsave(&hp->port.lock, flags); |
1da177e4 | 368 | |
0146b693 JS |
369 | if (--hp->port.count == 0) { |
370 | spin_unlock_irqrestore(&hp->port.lock, flags); | |
85bbc003 JS |
371 | /* We are done with the tty pointer now. */ |
372 | tty_port_tty_set(&hp->port, NULL); | |
1da177e4 | 373 | |
eef2622a CB |
374 | if (hp->ops->notifier_del) |
375 | hp->ops->notifier_del(hp, hp->data); | |
376 | ||
febde371 HB |
377 | /* cancel pending tty resize work */ |
378 | cancel_work_sync(&hp->tty_resize); | |
379 | ||
1da177e4 LT |
380 | /* |
381 | * Chain calls chars_in_buffer() and returns immediately if | |
382 | * there is no buffered data otherwise sleeps on a wait queue | |
383 | * waking periodically to check chars_in_buffer(). | |
384 | */ | |
0b058353 | 385 | tty_wait_until_sent_from_close(tty, HVC_CLOSE_WAIT); |
1da177e4 | 386 | } else { |
0146b693 | 387 | if (hp->port.count < 0) |
1da177e4 | 388 | printk(KERN_ERR "hvc_close %X: oops, count is %d\n", |
0146b693 JS |
389 | hp->vtermno, hp->port.count); |
390 | spin_unlock_irqrestore(&hp->port.lock, flags); | |
1da177e4 LT |
391 | } |
392 | ||
f3d9f250 | 393 | tty_port_put(&hp->port); |
1da177e4 LT |
394 | } |
395 | ||
396 | static void hvc_hangup(struct tty_struct *tty) | |
397 | { | |
398 | struct hvc_struct *hp = tty->driver_data; | |
399 | unsigned long flags; | |
1da177e4 | 400 | int temp_open_count; |
1da177e4 LT |
401 | |
402 | if (!hp) | |
403 | return; | |
404 | ||
febde371 HB |
405 | /* cancel pending tty resize work */ |
406 | cancel_work_sync(&hp->tty_resize); | |
407 | ||
0146b693 | 408 | spin_lock_irqsave(&hp->port.lock, flags); |
1da177e4 LT |
409 | |
410 | /* | |
411 | * The N_TTY line discipline has problems such that in a close vs | |
412 | * open->hangup case this can be called after the final close so prevent | |
413 | * that from happening for now. | |
414 | */ | |
0146b693 JS |
415 | if (hp->port.count <= 0) { |
416 | spin_unlock_irqrestore(&hp->port.lock, flags); | |
1da177e4 LT |
417 | return; |
418 | } | |
419 | ||
0146b693 JS |
420 | temp_open_count = hp->port.count; |
421 | hp->port.count = 0; | |
422 | spin_unlock_irqrestore(&hp->port.lock, flags); | |
85bbc003 | 423 | tty_port_tty_set(&hp->port, NULL); |
eef2622a | 424 | |
0146b693 JS |
425 | hp->n_outbuf = 0; |
426 | ||
fc362e2e | 427 | if (hp->ops->notifier_hangup) |
e74d098c | 428 | hp->ops->notifier_hangup(hp, hp->data); |
611e097d | 429 | |
1da177e4 LT |
430 | while(temp_open_count) { |
431 | --temp_open_count; | |
f3d9f250 | 432 | tty_port_put(&hp->port); |
1da177e4 LT |
433 | } |
434 | } | |
435 | ||
436 | /* | |
437 | * Push buffered characters whether they were just recently buffered or waiting | |
438 | * on a blocked hypervisor. Call this function with hp->lock held. | |
439 | */ | |
3feebbb5 | 440 | static int hvc_push(struct hvc_struct *hp) |
1da177e4 LT |
441 | { |
442 | int n; | |
443 | ||
030ffad2 | 444 | n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); |
1da177e4 | 445 | if (n <= 0) { |
8c2381af | 446 | if (n == 0 || n == -EAGAIN) { |
45d607ed | 447 | hp->do_wakeup = 1; |
3feebbb5 | 448 | return 0; |
45d607ed | 449 | } |
1da177e4 LT |
450 | /* throw away output on error; this happens when |
451 | there is no session connected to the vterm. */ | |
452 | hp->n_outbuf = 0; | |
453 | } else | |
454 | hp->n_outbuf -= n; | |
455 | if (hp->n_outbuf > 0) | |
456 | memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf); | |
457 | else | |
458 | hp->do_wakeup = 1; | |
3feebbb5 HB |
459 | |
460 | return n; | |
1da177e4 LT |
461 | } |
462 | ||
45d607ed | 463 | static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) |
1da177e4 | 464 | { |
45d607ed | 465 | struct hvc_struct *hp = tty->driver_data; |
1da177e4 LT |
466 | unsigned long flags; |
467 | int rsize, written = 0; | |
468 | ||
45d607ed RA |
469 | /* This write was probably executed during a tty close. */ |
470 | if (!hp) | |
471 | return -EPIPE; | |
472 | ||
0146b693 JS |
473 | /* FIXME what's this (unprotected) check for? */ |
474 | if (hp->port.count <= 0) | |
45d607ed RA |
475 | return -EIO; |
476 | ||
1da177e4 LT |
477 | spin_lock_irqsave(&hp->lock, flags); |
478 | ||
479 | /* Push pending writes */ | |
480 | if (hp->n_outbuf > 0) | |
481 | hvc_push(hp); | |
482 | ||
4e9e95a3 | 483 | while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) { |
1da177e4 LT |
484 | if (rsize > count) |
485 | rsize = count; | |
486 | memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); | |
487 | count -= rsize; | |
488 | buf += rsize; | |
489 | hp->n_outbuf += rsize; | |
490 | written += rsize; | |
491 | hvc_push(hp); | |
492 | } | |
493 | spin_unlock_irqrestore(&hp->lock, flags); | |
494 | ||
1da177e4 LT |
495 | /* |
496 | * Racy, but harmless, kick thread if there is still pending data. | |
1da177e4 LT |
497 | */ |
498 | if (hp->n_outbuf) | |
499 | hvc_kick(); | |
500 | ||
501 | return written; | |
502 | } | |
503 | ||
febde371 HB |
504 | /** |
505 | * hvc_set_winsz() - Resize the hvc tty terminal window. | |
506 | * @work: work structure. | |
507 | * | |
508 | * The routine shall not be called within an atomic context because it | |
509 | * might sleep. | |
510 | * | |
511 | * Locking: hp->lock | |
512 | */ | |
513 | static void hvc_set_winsz(struct work_struct *work) | |
514 | { | |
515 | struct hvc_struct *hp; | |
516 | unsigned long hvc_flags; | |
517 | struct tty_struct *tty; | |
518 | struct winsize ws; | |
519 | ||
520 | hp = container_of(work, struct hvc_struct, tty_resize); | |
febde371 | 521 | |
85bbc003 JS |
522 | tty = tty_port_tty_get(&hp->port); |
523 | if (!tty) | |
febde371 | 524 | return; |
85bbc003 JS |
525 | |
526 | spin_lock_irqsave(&hp->lock, hvc_flags); | |
527 | ws = hp->ws; | |
febde371 HB |
528 | spin_unlock_irqrestore(&hp->lock, hvc_flags); |
529 | ||
fc6f6238 | 530 | tty_do_resize(tty, &ws); |
febde371 HB |
531 | tty_kref_put(tty); |
532 | } | |
533 | ||
1da177e4 LT |
534 | /* |
535 | * This is actually a contract between the driver and the tty layer outlining | |
c3ea6921 | 536 | * how much write room the driver can guarantee will be sent OR BUFFERED. This |
1da177e4 LT |
537 | * driver MUST honor the return value. |
538 | */ | |
539 | static int hvc_write_room(struct tty_struct *tty) | |
540 | { | |
541 | struct hvc_struct *hp = tty->driver_data; | |
542 | ||
543 | if (!hp) | |
544 | return -1; | |
545 | ||
4e9e95a3 | 546 | return hp->outbuf_size - hp->n_outbuf; |
1da177e4 LT |
547 | } |
548 | ||
549 | static int hvc_chars_in_buffer(struct tty_struct *tty) | |
550 | { | |
551 | struct hvc_struct *hp = tty->driver_data; | |
552 | ||
553 | if (!hp) | |
23198fda | 554 | return 0; |
1da177e4 LT |
555 | return hp->n_outbuf; |
556 | } | |
557 | ||
b791072b WS |
558 | /* |
559 | * timeout will vary between the MIN and MAX values defined here. By default | |
560 | * and during console activity we will use a default MIN_TIMEOUT of 10. When | |
561 | * the console is idle, we increase the timeout value on each pass through | |
562 | * msleep until we reach the max. This may be noticeable as a brief (average | |
563 | * one second) delay on the console before the console responds to input when | |
564 | * there has been no input for some time. | |
565 | */ | |
566 | #define MIN_TIMEOUT (10) | |
567 | #define MAX_TIMEOUT (2000) | |
568 | static u32 timeout = MIN_TIMEOUT; | |
569 | ||
1da177e4 LT |
570 | #define HVC_POLL_READ 0x00000001 |
571 | #define HVC_POLL_WRITE 0x00000002 | |
1da177e4 | 572 | |
611e097d | 573 | int hvc_poll(struct hvc_struct *hp) |
1da177e4 LT |
574 | { |
575 | struct tty_struct *tty; | |
576 | int i, n, poll_mask = 0; | |
577 | char buf[N_INBUF] __ALIGNED__; | |
578 | unsigned long flags; | |
579 | int read_total = 0; | |
3feebbb5 | 580 | int written_total = 0; |
1da177e4 LT |
581 | |
582 | spin_lock_irqsave(&hp->lock, flags); | |
583 | ||
584 | /* Push pending writes */ | |
585 | if (hp->n_outbuf > 0) | |
3feebbb5 | 586 | written_total = hvc_push(hp); |
b5374461 | 587 | |
1da177e4 | 588 | /* Reschedule us if still some write pending */ |
3feebbb5 | 589 | if (hp->n_outbuf > 0) { |
1da177e4 | 590 | poll_mask |= HVC_POLL_WRITE; |
3feebbb5 HB |
591 | /* If hvc_push() was not able to write, sleep a few msecs */ |
592 | timeout = (written_total) ? 0 : MIN_TIMEOUT; | |
593 | } | |
1da177e4 LT |
594 | |
595 | /* No tty attached, just skip */ | |
85bbc003 | 596 | tty = tty_port_tty_get(&hp->port); |
1da177e4 LT |
597 | if (tty == NULL) |
598 | goto bail; | |
599 | ||
600 | /* Now check if we can get data (are we throttled ?) */ | |
601 | if (test_bit(TTY_THROTTLED, &tty->flags)) | |
602 | goto throttled; | |
603 | ||
611e097d | 604 | /* If we aren't notifier driven and aren't throttled, we always |
1da177e4 LT |
605 | * request a reschedule |
606 | */ | |
611e097d | 607 | if (!hp->irq_requested) |
1da177e4 LT |
608 | poll_mask |= HVC_POLL_READ; |
609 | ||
610 | /* Read data if any */ | |
611 | for (;;) { | |
33f0f88f | 612 | int count = tty_buffer_request_room(tty, N_INBUF); |
1da177e4 LT |
613 | |
614 | /* If flip is full, just reschedule a later read */ | |
615 | if (count == 0) { | |
616 | poll_mask |= HVC_POLL_READ; | |
617 | break; | |
618 | } | |
619 | ||
030ffad2 | 620 | n = hp->ops->get_chars(hp->vtermno, buf, count); |
1da177e4 LT |
621 | if (n <= 0) { |
622 | /* Hangup the tty when disconnected from host */ | |
623 | if (n == -EPIPE) { | |
624 | spin_unlock_irqrestore(&hp->lock, flags); | |
625 | tty_hangup(tty); | |
626 | spin_lock_irqsave(&hp->lock, flags); | |
45d607ed RA |
627 | } else if ( n == -EAGAIN ) { |
628 | /* | |
629 | * Some back-ends can only ensure a certain min | |
630 | * num of bytes read, which may be > 'count'. | |
631 | * Let the tty clear the flip buff to make room. | |
632 | */ | |
633 | poll_mask |= HVC_POLL_READ; | |
1da177e4 LT |
634 | } |
635 | break; | |
636 | } | |
637 | for (i = 0; i < n; ++i) { | |
638 | #ifdef CONFIG_MAGIC_SYSRQ | |
4455b119 | 639 | if (hp->index == hvc_console.index) { |
2b9e0bac MM |
640 | /* Handle the SysRq Hack */ |
641 | /* XXX should support a sequence */ | |
642 | if (buf[i] == '\x0f') { /* ^O */ | |
368c1e32 HB |
643 | /* if ^O is pressed again, reset |
644 | * sysrq_pressed and flip ^O char */ | |
645 | sysrq_pressed = !sysrq_pressed; | |
646 | if (sysrq_pressed) | |
647 | continue; | |
2b9e0bac | 648 | } else if (sysrq_pressed) { |
f335397d | 649 | handle_sysrq(buf[i]); |
2b9e0bac MM |
650 | sysrq_pressed = 0; |
651 | continue; | |
652 | } | |
1da177e4 LT |
653 | } |
654 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
655 | tty_insert_flip_char(tty, buf[i], 0); | |
656 | } | |
657 | ||
1da177e4 | 658 | read_total += n; |
1da177e4 LT |
659 | } |
660 | throttled: | |
661 | /* Wakeup write queue if necessary */ | |
662 | if (hp->do_wakeup) { | |
663 | hp->do_wakeup = 0; | |
664 | tty_wakeup(tty); | |
665 | } | |
666 | bail: | |
667 | spin_unlock_irqrestore(&hp->lock, flags); | |
668 | ||
b791072b WS |
669 | if (read_total) { |
670 | /* Activity is occurring, so reset the polling backoff value to | |
671 | a minimum for performance. */ | |
672 | timeout = MIN_TIMEOUT; | |
673 | ||
fb5c594c | 674 | tty_flip_buffer_push(tty); |
b791072b | 675 | } |
85bbc003 | 676 | tty_kref_put(tty); |
b791072b | 677 | |
1da177e4 LT |
678 | return poll_mask; |
679 | } | |
7721c494 | 680 | EXPORT_SYMBOL_GPL(hvc_poll); |
1da177e4 | 681 | |
febde371 | 682 | /** |
254be490 | 683 | * __hvc_resize() - Update terminal window size information. |
febde371 HB |
684 | * @hp: HVC console pointer |
685 | * @ws: Terminal window size structure | |
686 | * | |
687 | * Stores the specified window size information in the hvc structure of @hp. | |
688 | * The function schedule the tty resize update. | |
689 | * | |
690 | * Locking: Locking free; the function MUST be called holding hp->lock | |
691 | */ | |
254be490 | 692 | void __hvc_resize(struct hvc_struct *hp, struct winsize ws) |
febde371 | 693 | { |
7947cf0d HB |
694 | hp->ws = ws; |
695 | schedule_work(&hp->tty_resize); | |
febde371 | 696 | } |
254be490 | 697 | EXPORT_SYMBOL_GPL(__hvc_resize); |
febde371 | 698 | |
1da177e4 LT |
699 | /* |
700 | * This kthread is either polling or interrupt driven. This is determined by | |
701 | * calling hvc_poll() who determines whether a console adapter support | |
702 | * interrupts. | |
703 | */ | |
5605d4de | 704 | static int khvcd(void *unused) |
1da177e4 LT |
705 | { |
706 | int poll_mask; | |
707 | struct hvc_struct *hp; | |
708 | ||
83144186 | 709 | set_freezable(); |
1da177e4 LT |
710 | do { |
711 | poll_mask = 0; | |
712 | hvc_kicked = 0; | |
b64074e4 | 713 | try_to_freeze(); |
1da177e4 | 714 | wmb(); |
1c8950ff | 715 | if (!cpus_are_in_xmon()) { |
1da177e4 LT |
716 | spin_lock(&hvc_structs_lock); |
717 | list_for_each_entry(hp, &hvc_structs, next) { | |
1da177e4 LT |
718 | poll_mask |= hvc_poll(hp); |
719 | } | |
720 | spin_unlock(&hvc_structs_lock); | |
721 | } else | |
722 | poll_mask |= HVC_POLL_READ; | |
723 | if (hvc_kicked) | |
724 | continue; | |
1da177e4 LT |
725 | set_current_state(TASK_INTERRUPTIBLE); |
726 | if (!hvc_kicked) { | |
727 | if (poll_mask == 0) | |
728 | schedule(); | |
b791072b WS |
729 | else { |
730 | if (timeout < MAX_TIMEOUT) | |
731 | timeout += (timeout >> 6) + 1; | |
732 | ||
733 | msleep_interruptible(timeout); | |
734 | } | |
1da177e4 LT |
735 | } |
736 | __set_current_state(TASK_RUNNING); | |
737 | } while (!kthread_should_stop()); | |
738 | ||
739 | return 0; | |
740 | } | |
741 | ||
4d2bb3f5 BH |
742 | static int hvc_tiocmget(struct tty_struct *tty) |
743 | { | |
744 | struct hvc_struct *hp = tty->driver_data; | |
745 | ||
746 | if (!hp || !hp->ops->tiocmget) | |
747 | return -EINVAL; | |
748 | return hp->ops->tiocmget(hp); | |
749 | } | |
750 | ||
751 | static int hvc_tiocmset(struct tty_struct *tty, | |
752 | unsigned int set, unsigned int clear) | |
753 | { | |
754 | struct hvc_struct *hp = tty->driver_data; | |
755 | ||
756 | if (!hp || !hp->ops->tiocmset) | |
757 | return -EINVAL; | |
758 | return hp->ops->tiocmset(hp, set, clear); | |
759 | } | |
760 | ||
762e77ae AB |
761 | #ifdef CONFIG_CONSOLE_POLL |
762 | int hvc_poll_init(struct tty_driver *driver, int line, char *options) | |
763 | { | |
764 | return 0; | |
765 | } | |
766 | ||
767 | static int hvc_poll_get_char(struct tty_driver *driver, int line) | |
768 | { | |
769 | struct tty_struct *tty = driver->ttys[0]; | |
770 | struct hvc_struct *hp = tty->driver_data; | |
771 | int n; | |
772 | char ch; | |
773 | ||
774 | n = hp->ops->get_chars(hp->vtermno, &ch, 1); | |
775 | ||
776 | if (n == 0) | |
777 | return NO_POLL_CHAR; | |
778 | ||
779 | return ch; | |
780 | } | |
781 | ||
782 | static void hvc_poll_put_char(struct tty_driver *driver, int line, char ch) | |
783 | { | |
784 | struct tty_struct *tty = driver->ttys[0]; | |
785 | struct hvc_struct *hp = tty->driver_data; | |
786 | int n; | |
787 | ||
788 | do { | |
789 | n = hp->ops->put_chars(hp->vtermno, &ch, 1); | |
790 | } while (n <= 0); | |
791 | } | |
792 | #endif | |
793 | ||
b68e31d0 | 794 | static const struct tty_operations hvc_ops = { |
1da177e4 LT |
795 | .open = hvc_open, |
796 | .close = hvc_close, | |
797 | .write = hvc_write, | |
798 | .hangup = hvc_hangup, | |
799 | .unthrottle = hvc_unthrottle, | |
800 | .write_room = hvc_write_room, | |
801 | .chars_in_buffer = hvc_chars_in_buffer, | |
4d2bb3f5 BH |
802 | .tiocmget = hvc_tiocmget, |
803 | .tiocmset = hvc_tiocmset, | |
762e77ae AB |
804 | #ifdef CONFIG_CONSOLE_POLL |
805 | .poll_init = hvc_poll_init, | |
806 | .poll_get_char = hvc_poll_get_char, | |
807 | .poll_put_char = hvc_poll_put_char, | |
808 | #endif | |
1da177e4 LT |
809 | }; |
810 | ||
f3d9f250 JS |
811 | static const struct tty_port_operations hvc_port_ops = { |
812 | .destruct = hvc_port_destruct, | |
813 | }; | |
814 | ||
119ea109 AS |
815 | struct hvc_struct *hvc_alloc(uint32_t vtermno, int data, |
816 | const struct hv_ops *ops, | |
817 | int outbuf_size) | |
1da177e4 LT |
818 | { |
819 | struct hvc_struct *hp; | |
6f24808e | 820 | int i; |
1da177e4 | 821 | |
3e6c6f63 RR |
822 | /* We wait until a driver actually comes along */ |
823 | if (!hvc_driver) { | |
824 | int err = hvc_init(); | |
825 | if (err) | |
826 | return ERR_PTR(err); | |
827 | } | |
828 | ||
2da7582f | 829 | hp = kzalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size, |
4e9e95a3 | 830 | GFP_KERNEL); |
1da177e4 | 831 | if (!hp) |
acad9559 | 832 | return ERR_PTR(-ENOMEM); |
1da177e4 | 833 | |
acad9559 | 834 | hp->vtermno = vtermno; |
611e097d | 835 | hp->data = data; |
030ffad2 | 836 | hp->ops = ops; |
4e9e95a3 SR |
837 | hp->outbuf_size = outbuf_size; |
838 | hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))]; | |
1da177e4 | 839 | |
f3d9f250 JS |
840 | tty_port_init(&hp->port); |
841 | hp->port.ops = &hvc_port_ops; | |
1da177e4 | 842 | |
febde371 | 843 | INIT_WORK(&hp->tty_resize, hvc_set_winsz); |
1da177e4 LT |
844 | spin_lock_init(&hp->lock); |
845 | spin_lock(&hvc_structs_lock); | |
6f24808e MM |
846 | |
847 | /* | |
848 | * find index to use: | |
849 | * see if this vterm id matches one registered for console. | |
850 | */ | |
31555213 | 851 | for (i=0; i < MAX_NR_HVC_CONSOLES; i++) |
45d607ed RA |
852 | if (vtermnos[i] == hp->vtermno && |
853 | cons_ops[i] == hp->ops) | |
6f24808e MM |
854 | break; |
855 | ||
856 | /* no matching slot, just use a counter */ | |
857 | if (i >= MAX_NR_HVC_CONSOLES) | |
858 | i = ++last_hvc; | |
859 | ||
860 | hp->index = i; | |
861 | ||
1da177e4 LT |
862 | list_add_tail(&(hp->next), &hvc_structs); |
863 | spin_unlock(&hvc_structs_lock); | |
864 | ||
acad9559 | 865 | return hp; |
1da177e4 | 866 | } |
7721c494 | 867 | EXPORT_SYMBOL_GPL(hvc_alloc); |
1da177e4 | 868 | |
934752d8 | 869 | int hvc_remove(struct hvc_struct *hp) |
1da177e4 | 870 | { |
1da177e4 | 871 | unsigned long flags; |
1da177e4 LT |
872 | struct tty_struct *tty; |
873 | ||
85bbc003 | 874 | tty = tty_port_tty_get(&hp->port); |
1da177e4 | 875 | |
85bbc003 | 876 | spin_lock_irqsave(&hp->lock, flags); |
1da177e4 LT |
877 | if (hp->index < MAX_NR_HVC_CONSOLES) |
878 | vtermnos[hp->index] = -1; | |
879 | ||
880 | /* Don't whack hp->irq because tty_hangup() will need to free the irq. */ | |
881 | ||
882 | spin_unlock_irqrestore(&hp->lock, flags); | |
883 | ||
884 | /* | |
12b20ded GKH |
885 | * We 'put' the instance that was grabbed when the kref instance |
886 | * was initialized using kref_init(). Let the last holder of this | |
e74d098c | 887 | * kref cause it to be removed, which will probably be the tty_vhangup |
1da177e4 LT |
888 | * below. |
889 | */ | |
f3d9f250 | 890 | tty_port_put(&hp->port); |
1da177e4 LT |
891 | |
892 | /* | |
e74d098c | 893 | * This function call will auto chain call hvc_hangup. |
1da177e4 | 894 | */ |
e74d098c AS |
895 | if (tty) { |
896 | tty_vhangup(tty); | |
897 | tty_kref_put(tty); | |
898 | } | |
1da177e4 LT |
899 | return 0; |
900 | } | |
c0cefebc | 901 | EXPORT_SYMBOL_GPL(hvc_remove); |
1da177e4 | 902 | |
3e6c6f63 RR |
903 | /* Driver initialization: called as soon as someone uses hvc_alloc(). */ |
904 | static int hvc_init(void) | |
1da177e4 | 905 | { |
55aab8cd | 906 | struct tty_driver *drv; |
3e6c6f63 | 907 | int err; |
55aab8cd | 908 | |
5f6d9c07 | 909 | /* We need more than hvc_count adapters due to hotplug additions. */ |
55aab8cd | 910 | drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS); |
3e6c6f63 RR |
911 | if (!drv) { |
912 | err = -ENOMEM; | |
913 | goto out; | |
914 | } | |
1da177e4 | 915 | |
55aab8cd MN |
916 | drv->driver_name = "hvc"; |
917 | drv->name = "hvc"; | |
918 | drv->major = HVC_MAJOR; | |
919 | drv->minor_start = HVC_MINOR; | |
920 | drv->type = TTY_DRIVER_TYPE_SYSTEM; | |
921 | drv->init_termios = tty_std_termios; | |
56ce9e2b | 922 | drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS; |
55aab8cd | 923 | tty_set_operations(drv, &hvc_ops); |
1da177e4 | 924 | |
1da177e4 LT |
925 | /* Always start the kthread because there can be hotplug vty adapters |
926 | * added later. */ | |
927 | hvc_task = kthread_run(khvcd, NULL, "khvcd"); | |
928 | if (IS_ERR(hvc_task)) { | |
3e6c6f63 RR |
929 | printk(KERN_ERR "Couldn't create kthread for console.\n"); |
930 | err = PTR_ERR(hvc_task); | |
931 | goto put_tty; | |
1da177e4 LT |
932 | } |
933 | ||
3e6c6f63 RR |
934 | err = tty_register_driver(drv); |
935 | if (err) { | |
936 | printk(KERN_ERR "Couldn't register hvc console driver\n"); | |
937 | goto stop_thread; | |
938 | } | |
ef4cbee0 | 939 | |
9fef3d2d MM |
940 | /* |
941 | * Make sure tty is fully registered before allowing it to be | |
942 | * found by hvc_console_device. | |
943 | */ | |
944 | smp_mb(); | |
55aab8cd | 945 | hvc_driver = drv; |
acad9559 | 946 | return 0; |
3e6c6f63 | 947 | |
3e6c6f63 RR |
948 | stop_thread: |
949 | kthread_stop(hvc_task); | |
950 | hvc_task = NULL; | |
2571cd6a JL |
951 | put_tty: |
952 | put_tty_driver(drv); | |
3e6c6f63 RR |
953 | out: |
954 | return err; | |
1da177e4 LT |
955 | } |
956 | ||
c3ea6921 | 957 | /* This isn't particularly necessary due to this being a console driver |
320da0d2 MM |
958 | * but it is nice to be thorough. |
959 | */ | |
1da177e4 LT |
960 | static void __exit hvc_exit(void) |
961 | { | |
3e6c6f63 RR |
962 | if (hvc_driver) { |
963 | kthread_stop(hvc_task); | |
1da177e4 | 964 | |
3e6c6f63 RR |
965 | tty_unregister_driver(hvc_driver); |
966 | /* return tty_struct instances allocated in hvc_init(). */ | |
967 | put_tty_driver(hvc_driver); | |
4455b119 | 968 | unregister_console(&hvc_console); |
3e6c6f63 | 969 | } |
1da177e4 | 970 | } |
1da177e4 | 971 | module_exit(hvc_exit); |