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 | ||
bdb498c2 JS |
302 | static int hvc_install(struct tty_driver *driver, struct tty_struct *tty) |
303 | { | |
304 | struct hvc_struct *hp; | |
305 | int rc; | |
306 | ||
307 | /* Auto increments kref reference if found. */ | |
308 | if (!(hp = hvc_get_by_index(tty->index))) | |
309 | return -ENODEV; | |
310 | ||
311 | tty->driver_data = hp; | |
312 | ||
313 | rc = tty_port_install(&hp->port, driver, tty); | |
314 | if (rc) | |
315 | tty_port_put(&hp->port); | |
316 | return rc; | |
317 | } | |
318 | ||
1da177e4 LT |
319 | /* |
320 | * The TTY interface won't be used until after the vio layer has exposed the vty | |
321 | * adapter to the kernel. | |
322 | */ | |
323 | static int hvc_open(struct tty_struct *tty, struct file * filp) | |
324 | { | |
bdb498c2 | 325 | struct hvc_struct *hp = tty->driver_data; |
1da177e4 | 326 | unsigned long flags; |
1da177e4 | 327 | int rc = 0; |
1da177e4 | 328 | |
0146b693 | 329 | spin_lock_irqsave(&hp->port.lock, flags); |
1da177e4 | 330 | /* Check and then increment for fast path open. */ |
0146b693 JS |
331 | if (hp->port.count++ > 0) { |
332 | spin_unlock_irqrestore(&hp->port.lock, flags); | |
1da177e4 LT |
333 | hvc_kick(); |
334 | return 0; | |
335 | } /* else count == 0 */ | |
0146b693 | 336 | spin_unlock_irqrestore(&hp->port.lock, flags); |
1da177e4 | 337 | |
85bbc003 JS |
338 | tty_port_tty_set(&hp->port, tty); |
339 | ||
b1b135c8 CB |
340 | if (hp->ops->notifier_add) |
341 | rc = hp->ops->notifier_add(hp, hp->data); | |
1da177e4 LT |
342 | |
343 | /* | |
611e097d | 344 | * If the notifier fails we return an error. The tty layer |
1da177e4 LT |
345 | * will call hvc_close() after a failed open but we don't want to clean |
346 | * up there so we'll clean up here and clear out the previously set | |
12b20ded | 347 | * tty fields and return the kref reference. |
1da177e4 LT |
348 | */ |
349 | if (rc) { | |
85bbc003 | 350 | tty_port_tty_set(&hp->port, NULL); |
1da177e4 | 351 | tty->driver_data = NULL; |
f3d9f250 | 352 | tty_port_put(&hp->port); |
1da177e4 LT |
353 | printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc); |
354 | } | |
355 | /* Force wakeup of the polling thread */ | |
356 | hvc_kick(); | |
357 | ||
358 | return rc; | |
359 | } | |
360 | ||
361 | static void hvc_close(struct tty_struct *tty, struct file * filp) | |
362 | { | |
363 | struct hvc_struct *hp; | |
1da177e4 LT |
364 | unsigned long flags; |
365 | ||
366 | if (tty_hung_up_p(filp)) | |
367 | return; | |
368 | ||
369 | /* | |
370 | * No driver_data means that this close was issued after a failed | |
371 | * hvc_open by the tty layer's release_dev() function and we can just | |
12b20ded | 372 | * exit cleanly because the kref reference wasn't made. |
1da177e4 LT |
373 | */ |
374 | if (!tty->driver_data) | |
375 | return; | |
376 | ||
377 | hp = tty->driver_data; | |
e74d098c | 378 | |
0146b693 | 379 | spin_lock_irqsave(&hp->port.lock, flags); |
1da177e4 | 380 | |
0146b693 JS |
381 | if (--hp->port.count == 0) { |
382 | spin_unlock_irqrestore(&hp->port.lock, flags); | |
85bbc003 JS |
383 | /* We are done with the tty pointer now. */ |
384 | tty_port_tty_set(&hp->port, NULL); | |
1da177e4 | 385 | |
eef2622a CB |
386 | if (hp->ops->notifier_del) |
387 | hp->ops->notifier_del(hp, hp->data); | |
388 | ||
febde371 HB |
389 | /* cancel pending tty resize work */ |
390 | cancel_work_sync(&hp->tty_resize); | |
391 | ||
1da177e4 LT |
392 | /* |
393 | * Chain calls chars_in_buffer() and returns immediately if | |
394 | * there is no buffered data otherwise sleeps on a wait queue | |
395 | * waking periodically to check chars_in_buffer(). | |
396 | */ | |
0b058353 | 397 | tty_wait_until_sent_from_close(tty, HVC_CLOSE_WAIT); |
1da177e4 | 398 | } else { |
0146b693 | 399 | if (hp->port.count < 0) |
1da177e4 | 400 | printk(KERN_ERR "hvc_close %X: oops, count is %d\n", |
0146b693 JS |
401 | hp->vtermno, hp->port.count); |
402 | spin_unlock_irqrestore(&hp->port.lock, flags); | |
1da177e4 | 403 | } |
bdb498c2 JS |
404 | } |
405 | ||
406 | static void hvc_cleanup(struct tty_struct *tty) | |
407 | { | |
408 | struct hvc_struct *hp = tty->driver_data; | |
1da177e4 | 409 | |
f3d9f250 | 410 | tty_port_put(&hp->port); |
1da177e4 LT |
411 | } |
412 | ||
413 | static void hvc_hangup(struct tty_struct *tty) | |
414 | { | |
415 | struct hvc_struct *hp = tty->driver_data; | |
416 | unsigned long flags; | |
1da177e4 | 417 | int temp_open_count; |
1da177e4 LT |
418 | |
419 | if (!hp) | |
420 | return; | |
421 | ||
febde371 HB |
422 | /* cancel pending tty resize work */ |
423 | cancel_work_sync(&hp->tty_resize); | |
424 | ||
0146b693 | 425 | spin_lock_irqsave(&hp->port.lock, flags); |
1da177e4 LT |
426 | |
427 | /* | |
428 | * The N_TTY line discipline has problems such that in a close vs | |
429 | * open->hangup case this can be called after the final close so prevent | |
430 | * that from happening for now. | |
431 | */ | |
0146b693 JS |
432 | if (hp->port.count <= 0) { |
433 | spin_unlock_irqrestore(&hp->port.lock, flags); | |
1da177e4 LT |
434 | return; |
435 | } | |
436 | ||
0146b693 JS |
437 | temp_open_count = hp->port.count; |
438 | hp->port.count = 0; | |
439 | spin_unlock_irqrestore(&hp->port.lock, flags); | |
85bbc003 | 440 | tty_port_tty_set(&hp->port, NULL); |
eef2622a | 441 | |
0146b693 JS |
442 | hp->n_outbuf = 0; |
443 | ||
fc362e2e | 444 | if (hp->ops->notifier_hangup) |
e74d098c | 445 | hp->ops->notifier_hangup(hp, hp->data); |
611e097d | 446 | |
1da177e4 LT |
447 | while(temp_open_count) { |
448 | --temp_open_count; | |
f3d9f250 | 449 | tty_port_put(&hp->port); |
1da177e4 LT |
450 | } |
451 | } | |
452 | ||
453 | /* | |
454 | * Push buffered characters whether they were just recently buffered or waiting | |
455 | * on a blocked hypervisor. Call this function with hp->lock held. | |
456 | */ | |
3feebbb5 | 457 | static int hvc_push(struct hvc_struct *hp) |
1da177e4 LT |
458 | { |
459 | int n; | |
460 | ||
030ffad2 | 461 | n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); |
1da177e4 | 462 | if (n <= 0) { |
8c2381af | 463 | if (n == 0 || n == -EAGAIN) { |
45d607ed | 464 | hp->do_wakeup = 1; |
3feebbb5 | 465 | return 0; |
45d607ed | 466 | } |
1da177e4 LT |
467 | /* throw away output on error; this happens when |
468 | there is no session connected to the vterm. */ | |
469 | hp->n_outbuf = 0; | |
470 | } else | |
471 | hp->n_outbuf -= n; | |
472 | if (hp->n_outbuf > 0) | |
473 | memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf); | |
474 | else | |
475 | hp->do_wakeup = 1; | |
3feebbb5 HB |
476 | |
477 | return n; | |
1da177e4 LT |
478 | } |
479 | ||
45d607ed | 480 | static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) |
1da177e4 | 481 | { |
45d607ed | 482 | struct hvc_struct *hp = tty->driver_data; |
1da177e4 LT |
483 | unsigned long flags; |
484 | int rsize, written = 0; | |
485 | ||
45d607ed RA |
486 | /* This write was probably executed during a tty close. */ |
487 | if (!hp) | |
488 | return -EPIPE; | |
489 | ||
0146b693 JS |
490 | /* FIXME what's this (unprotected) check for? */ |
491 | if (hp->port.count <= 0) | |
45d607ed RA |
492 | return -EIO; |
493 | ||
1da177e4 LT |
494 | spin_lock_irqsave(&hp->lock, flags); |
495 | ||
496 | /* Push pending writes */ | |
497 | if (hp->n_outbuf > 0) | |
498 | hvc_push(hp); | |
499 | ||
4e9e95a3 | 500 | while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) { |
1da177e4 LT |
501 | if (rsize > count) |
502 | rsize = count; | |
503 | memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); | |
504 | count -= rsize; | |
505 | buf += rsize; | |
506 | hp->n_outbuf += rsize; | |
507 | written += rsize; | |
508 | hvc_push(hp); | |
509 | } | |
510 | spin_unlock_irqrestore(&hp->lock, flags); | |
511 | ||
1da177e4 LT |
512 | /* |
513 | * Racy, but harmless, kick thread if there is still pending data. | |
1da177e4 LT |
514 | */ |
515 | if (hp->n_outbuf) | |
516 | hvc_kick(); | |
517 | ||
518 | return written; | |
519 | } | |
520 | ||
febde371 HB |
521 | /** |
522 | * hvc_set_winsz() - Resize the hvc tty terminal window. | |
523 | * @work: work structure. | |
524 | * | |
525 | * The routine shall not be called within an atomic context because it | |
526 | * might sleep. | |
527 | * | |
528 | * Locking: hp->lock | |
529 | */ | |
530 | static void hvc_set_winsz(struct work_struct *work) | |
531 | { | |
532 | struct hvc_struct *hp; | |
533 | unsigned long hvc_flags; | |
534 | struct tty_struct *tty; | |
535 | struct winsize ws; | |
536 | ||
537 | hp = container_of(work, struct hvc_struct, tty_resize); | |
febde371 | 538 | |
85bbc003 JS |
539 | tty = tty_port_tty_get(&hp->port); |
540 | if (!tty) | |
febde371 | 541 | return; |
85bbc003 JS |
542 | |
543 | spin_lock_irqsave(&hp->lock, hvc_flags); | |
544 | ws = hp->ws; | |
febde371 HB |
545 | spin_unlock_irqrestore(&hp->lock, hvc_flags); |
546 | ||
fc6f6238 | 547 | tty_do_resize(tty, &ws); |
febde371 HB |
548 | tty_kref_put(tty); |
549 | } | |
550 | ||
1da177e4 LT |
551 | /* |
552 | * This is actually a contract between the driver and the tty layer outlining | |
c3ea6921 | 553 | * how much write room the driver can guarantee will be sent OR BUFFERED. This |
1da177e4 LT |
554 | * driver MUST honor the return value. |
555 | */ | |
556 | static int hvc_write_room(struct tty_struct *tty) | |
557 | { | |
558 | struct hvc_struct *hp = tty->driver_data; | |
559 | ||
560 | if (!hp) | |
561 | return -1; | |
562 | ||
4e9e95a3 | 563 | return hp->outbuf_size - hp->n_outbuf; |
1da177e4 LT |
564 | } |
565 | ||
566 | static int hvc_chars_in_buffer(struct tty_struct *tty) | |
567 | { | |
568 | struct hvc_struct *hp = tty->driver_data; | |
569 | ||
570 | if (!hp) | |
23198fda | 571 | return 0; |
1da177e4 LT |
572 | return hp->n_outbuf; |
573 | } | |
574 | ||
b791072b WS |
575 | /* |
576 | * timeout will vary between the MIN and MAX values defined here. By default | |
577 | * and during console activity we will use a default MIN_TIMEOUT of 10. When | |
578 | * the console is idle, we increase the timeout value on each pass through | |
579 | * msleep until we reach the max. This may be noticeable as a brief (average | |
580 | * one second) delay on the console before the console responds to input when | |
581 | * there has been no input for some time. | |
582 | */ | |
583 | #define MIN_TIMEOUT (10) | |
584 | #define MAX_TIMEOUT (2000) | |
585 | static u32 timeout = MIN_TIMEOUT; | |
586 | ||
1da177e4 LT |
587 | #define HVC_POLL_READ 0x00000001 |
588 | #define HVC_POLL_WRITE 0x00000002 | |
1da177e4 | 589 | |
611e097d | 590 | int hvc_poll(struct hvc_struct *hp) |
1da177e4 LT |
591 | { |
592 | struct tty_struct *tty; | |
593 | int i, n, poll_mask = 0; | |
594 | char buf[N_INBUF] __ALIGNED__; | |
595 | unsigned long flags; | |
596 | int read_total = 0; | |
3feebbb5 | 597 | int written_total = 0; |
1da177e4 LT |
598 | |
599 | spin_lock_irqsave(&hp->lock, flags); | |
600 | ||
601 | /* Push pending writes */ | |
602 | if (hp->n_outbuf > 0) | |
3feebbb5 | 603 | written_total = hvc_push(hp); |
b5374461 | 604 | |
1da177e4 | 605 | /* Reschedule us if still some write pending */ |
3feebbb5 | 606 | if (hp->n_outbuf > 0) { |
1da177e4 | 607 | poll_mask |= HVC_POLL_WRITE; |
3feebbb5 HB |
608 | /* If hvc_push() was not able to write, sleep a few msecs */ |
609 | timeout = (written_total) ? 0 : MIN_TIMEOUT; | |
610 | } | |
1da177e4 LT |
611 | |
612 | /* No tty attached, just skip */ | |
85bbc003 | 613 | tty = tty_port_tty_get(&hp->port); |
1da177e4 LT |
614 | if (tty == NULL) |
615 | goto bail; | |
616 | ||
617 | /* Now check if we can get data (are we throttled ?) */ | |
618 | if (test_bit(TTY_THROTTLED, &tty->flags)) | |
619 | goto throttled; | |
620 | ||
611e097d | 621 | /* If we aren't notifier driven and aren't throttled, we always |
1da177e4 LT |
622 | * request a reschedule |
623 | */ | |
611e097d | 624 | if (!hp->irq_requested) |
1da177e4 LT |
625 | poll_mask |= HVC_POLL_READ; |
626 | ||
627 | /* Read data if any */ | |
628 | for (;;) { | |
33f0f88f | 629 | int count = tty_buffer_request_room(tty, N_INBUF); |
1da177e4 LT |
630 | |
631 | /* If flip is full, just reschedule a later read */ | |
632 | if (count == 0) { | |
633 | poll_mask |= HVC_POLL_READ; | |
634 | break; | |
635 | } | |
636 | ||
030ffad2 | 637 | n = hp->ops->get_chars(hp->vtermno, buf, count); |
1da177e4 LT |
638 | if (n <= 0) { |
639 | /* Hangup the tty when disconnected from host */ | |
640 | if (n == -EPIPE) { | |
641 | spin_unlock_irqrestore(&hp->lock, flags); | |
642 | tty_hangup(tty); | |
643 | spin_lock_irqsave(&hp->lock, flags); | |
45d607ed RA |
644 | } else if ( n == -EAGAIN ) { |
645 | /* | |
646 | * Some back-ends can only ensure a certain min | |
647 | * num of bytes read, which may be > 'count'. | |
648 | * Let the tty clear the flip buff to make room. | |
649 | */ | |
650 | poll_mask |= HVC_POLL_READ; | |
1da177e4 LT |
651 | } |
652 | break; | |
653 | } | |
654 | for (i = 0; i < n; ++i) { | |
655 | #ifdef CONFIG_MAGIC_SYSRQ | |
4455b119 | 656 | if (hp->index == hvc_console.index) { |
2b9e0bac MM |
657 | /* Handle the SysRq Hack */ |
658 | /* XXX should support a sequence */ | |
659 | if (buf[i] == '\x0f') { /* ^O */ | |
368c1e32 HB |
660 | /* if ^O is pressed again, reset |
661 | * sysrq_pressed and flip ^O char */ | |
662 | sysrq_pressed = !sysrq_pressed; | |
663 | if (sysrq_pressed) | |
664 | continue; | |
2b9e0bac | 665 | } else if (sysrq_pressed) { |
f335397d | 666 | handle_sysrq(buf[i]); |
2b9e0bac MM |
667 | sysrq_pressed = 0; |
668 | continue; | |
669 | } | |
1da177e4 LT |
670 | } |
671 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
672 | tty_insert_flip_char(tty, buf[i], 0); | |
673 | } | |
674 | ||
1da177e4 | 675 | read_total += n; |
1da177e4 LT |
676 | } |
677 | throttled: | |
678 | /* Wakeup write queue if necessary */ | |
679 | if (hp->do_wakeup) { | |
680 | hp->do_wakeup = 0; | |
681 | tty_wakeup(tty); | |
682 | } | |
683 | bail: | |
684 | spin_unlock_irqrestore(&hp->lock, flags); | |
685 | ||
b791072b WS |
686 | if (read_total) { |
687 | /* Activity is occurring, so reset the polling backoff value to | |
688 | a minimum for performance. */ | |
689 | timeout = MIN_TIMEOUT; | |
690 | ||
fb5c594c | 691 | tty_flip_buffer_push(tty); |
b791072b | 692 | } |
85bbc003 | 693 | tty_kref_put(tty); |
b791072b | 694 | |
1da177e4 LT |
695 | return poll_mask; |
696 | } | |
7721c494 | 697 | EXPORT_SYMBOL_GPL(hvc_poll); |
1da177e4 | 698 | |
febde371 | 699 | /** |
254be490 | 700 | * __hvc_resize() - Update terminal window size information. |
febde371 HB |
701 | * @hp: HVC console pointer |
702 | * @ws: Terminal window size structure | |
703 | * | |
704 | * Stores the specified window size information in the hvc structure of @hp. | |
705 | * The function schedule the tty resize update. | |
706 | * | |
707 | * Locking: Locking free; the function MUST be called holding hp->lock | |
708 | */ | |
254be490 | 709 | void __hvc_resize(struct hvc_struct *hp, struct winsize ws) |
febde371 | 710 | { |
7947cf0d HB |
711 | hp->ws = ws; |
712 | schedule_work(&hp->tty_resize); | |
febde371 | 713 | } |
254be490 | 714 | EXPORT_SYMBOL_GPL(__hvc_resize); |
febde371 | 715 | |
1da177e4 LT |
716 | /* |
717 | * This kthread is either polling or interrupt driven. This is determined by | |
718 | * calling hvc_poll() who determines whether a console adapter support | |
719 | * interrupts. | |
720 | */ | |
5605d4de | 721 | static int khvcd(void *unused) |
1da177e4 LT |
722 | { |
723 | int poll_mask; | |
724 | struct hvc_struct *hp; | |
725 | ||
83144186 | 726 | set_freezable(); |
1da177e4 LT |
727 | do { |
728 | poll_mask = 0; | |
729 | hvc_kicked = 0; | |
b64074e4 | 730 | try_to_freeze(); |
1da177e4 | 731 | wmb(); |
1c8950ff | 732 | if (!cpus_are_in_xmon()) { |
1da177e4 LT |
733 | spin_lock(&hvc_structs_lock); |
734 | list_for_each_entry(hp, &hvc_structs, next) { | |
1da177e4 LT |
735 | poll_mask |= hvc_poll(hp); |
736 | } | |
737 | spin_unlock(&hvc_structs_lock); | |
738 | } else | |
739 | poll_mask |= HVC_POLL_READ; | |
740 | if (hvc_kicked) | |
741 | continue; | |
1da177e4 LT |
742 | set_current_state(TASK_INTERRUPTIBLE); |
743 | if (!hvc_kicked) { | |
744 | if (poll_mask == 0) | |
745 | schedule(); | |
b791072b WS |
746 | else { |
747 | if (timeout < MAX_TIMEOUT) | |
748 | timeout += (timeout >> 6) + 1; | |
749 | ||
750 | msleep_interruptible(timeout); | |
751 | } | |
1da177e4 LT |
752 | } |
753 | __set_current_state(TASK_RUNNING); | |
754 | } while (!kthread_should_stop()); | |
755 | ||
756 | return 0; | |
757 | } | |
758 | ||
4d2bb3f5 BH |
759 | static int hvc_tiocmget(struct tty_struct *tty) |
760 | { | |
761 | struct hvc_struct *hp = tty->driver_data; | |
762 | ||
763 | if (!hp || !hp->ops->tiocmget) | |
764 | return -EINVAL; | |
765 | return hp->ops->tiocmget(hp); | |
766 | } | |
767 | ||
768 | static int hvc_tiocmset(struct tty_struct *tty, | |
769 | unsigned int set, unsigned int clear) | |
770 | { | |
771 | struct hvc_struct *hp = tty->driver_data; | |
772 | ||
773 | if (!hp || !hp->ops->tiocmset) | |
774 | return -EINVAL; | |
775 | return hp->ops->tiocmset(hp, set, clear); | |
776 | } | |
777 | ||
762e77ae AB |
778 | #ifdef CONFIG_CONSOLE_POLL |
779 | int hvc_poll_init(struct tty_driver *driver, int line, char *options) | |
780 | { | |
781 | return 0; | |
782 | } | |
783 | ||
784 | static int hvc_poll_get_char(struct tty_driver *driver, int line) | |
785 | { | |
786 | struct tty_struct *tty = driver->ttys[0]; | |
787 | struct hvc_struct *hp = tty->driver_data; | |
788 | int n; | |
789 | char ch; | |
790 | ||
791 | n = hp->ops->get_chars(hp->vtermno, &ch, 1); | |
792 | ||
793 | if (n == 0) | |
794 | return NO_POLL_CHAR; | |
795 | ||
796 | return ch; | |
797 | } | |
798 | ||
799 | static void hvc_poll_put_char(struct tty_driver *driver, int line, char ch) | |
800 | { | |
801 | struct tty_struct *tty = driver->ttys[0]; | |
802 | struct hvc_struct *hp = tty->driver_data; | |
803 | int n; | |
804 | ||
805 | do { | |
806 | n = hp->ops->put_chars(hp->vtermno, &ch, 1); | |
807 | } while (n <= 0); | |
808 | } | |
809 | #endif | |
810 | ||
b68e31d0 | 811 | static const struct tty_operations hvc_ops = { |
bdb498c2 | 812 | .install = hvc_install, |
1da177e4 LT |
813 | .open = hvc_open, |
814 | .close = hvc_close, | |
bdb498c2 | 815 | .cleanup = hvc_cleanup, |
1da177e4 LT |
816 | .write = hvc_write, |
817 | .hangup = hvc_hangup, | |
818 | .unthrottle = hvc_unthrottle, | |
819 | .write_room = hvc_write_room, | |
820 | .chars_in_buffer = hvc_chars_in_buffer, | |
4d2bb3f5 BH |
821 | .tiocmget = hvc_tiocmget, |
822 | .tiocmset = hvc_tiocmset, | |
762e77ae AB |
823 | #ifdef CONFIG_CONSOLE_POLL |
824 | .poll_init = hvc_poll_init, | |
825 | .poll_get_char = hvc_poll_get_char, | |
826 | .poll_put_char = hvc_poll_put_char, | |
827 | #endif | |
1da177e4 LT |
828 | }; |
829 | ||
f3d9f250 JS |
830 | static const struct tty_port_operations hvc_port_ops = { |
831 | .destruct = hvc_port_destruct, | |
832 | }; | |
833 | ||
119ea109 AS |
834 | struct hvc_struct *hvc_alloc(uint32_t vtermno, int data, |
835 | const struct hv_ops *ops, | |
836 | int outbuf_size) | |
1da177e4 LT |
837 | { |
838 | struct hvc_struct *hp; | |
6f24808e | 839 | int i; |
1da177e4 | 840 | |
3e6c6f63 RR |
841 | /* We wait until a driver actually comes along */ |
842 | if (!hvc_driver) { | |
843 | int err = hvc_init(); | |
844 | if (err) | |
845 | return ERR_PTR(err); | |
846 | } | |
847 | ||
2da7582f | 848 | hp = kzalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size, |
4e9e95a3 | 849 | GFP_KERNEL); |
1da177e4 | 850 | if (!hp) |
acad9559 | 851 | return ERR_PTR(-ENOMEM); |
1da177e4 | 852 | |
acad9559 | 853 | hp->vtermno = vtermno; |
611e097d | 854 | hp->data = data; |
030ffad2 | 855 | hp->ops = ops; |
4e9e95a3 SR |
856 | hp->outbuf_size = outbuf_size; |
857 | hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))]; | |
1da177e4 | 858 | |
f3d9f250 JS |
859 | tty_port_init(&hp->port); |
860 | hp->port.ops = &hvc_port_ops; | |
1da177e4 | 861 | |
febde371 | 862 | INIT_WORK(&hp->tty_resize, hvc_set_winsz); |
1da177e4 LT |
863 | spin_lock_init(&hp->lock); |
864 | spin_lock(&hvc_structs_lock); | |
6f24808e MM |
865 | |
866 | /* | |
867 | * find index to use: | |
868 | * see if this vterm id matches one registered for console. | |
869 | */ | |
31555213 | 870 | for (i=0; i < MAX_NR_HVC_CONSOLES; i++) |
45d607ed RA |
871 | if (vtermnos[i] == hp->vtermno && |
872 | cons_ops[i] == hp->ops) | |
6f24808e MM |
873 | break; |
874 | ||
875 | /* no matching slot, just use a counter */ | |
876 | if (i >= MAX_NR_HVC_CONSOLES) | |
877 | i = ++last_hvc; | |
878 | ||
879 | hp->index = i; | |
880 | ||
1da177e4 LT |
881 | list_add_tail(&(hp->next), &hvc_structs); |
882 | spin_unlock(&hvc_structs_lock); | |
883 | ||
acad9559 | 884 | return hp; |
1da177e4 | 885 | } |
7721c494 | 886 | EXPORT_SYMBOL_GPL(hvc_alloc); |
1da177e4 | 887 | |
934752d8 | 888 | int hvc_remove(struct hvc_struct *hp) |
1da177e4 | 889 | { |
1da177e4 | 890 | unsigned long flags; |
1da177e4 LT |
891 | struct tty_struct *tty; |
892 | ||
85bbc003 | 893 | tty = tty_port_tty_get(&hp->port); |
1da177e4 | 894 | |
85bbc003 | 895 | spin_lock_irqsave(&hp->lock, flags); |
1da177e4 LT |
896 | if (hp->index < MAX_NR_HVC_CONSOLES) |
897 | vtermnos[hp->index] = -1; | |
898 | ||
899 | /* Don't whack hp->irq because tty_hangup() will need to free the irq. */ | |
900 | ||
901 | spin_unlock_irqrestore(&hp->lock, flags); | |
902 | ||
903 | /* | |
12b20ded GKH |
904 | * We 'put' the instance that was grabbed when the kref instance |
905 | * was initialized using kref_init(). Let the last holder of this | |
e74d098c | 906 | * kref cause it to be removed, which will probably be the tty_vhangup |
1da177e4 LT |
907 | * below. |
908 | */ | |
f3d9f250 | 909 | tty_port_put(&hp->port); |
1da177e4 LT |
910 | |
911 | /* | |
e74d098c | 912 | * This function call will auto chain call hvc_hangup. |
1da177e4 | 913 | */ |
e74d098c AS |
914 | if (tty) { |
915 | tty_vhangup(tty); | |
916 | tty_kref_put(tty); | |
917 | } | |
1da177e4 LT |
918 | return 0; |
919 | } | |
c0cefebc | 920 | EXPORT_SYMBOL_GPL(hvc_remove); |
1da177e4 | 921 | |
3e6c6f63 RR |
922 | /* Driver initialization: called as soon as someone uses hvc_alloc(). */ |
923 | static int hvc_init(void) | |
1da177e4 | 924 | { |
55aab8cd | 925 | struct tty_driver *drv; |
3e6c6f63 | 926 | int err; |
55aab8cd | 927 | |
5f6d9c07 | 928 | /* We need more than hvc_count adapters due to hotplug additions. */ |
55aab8cd | 929 | drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS); |
3e6c6f63 RR |
930 | if (!drv) { |
931 | err = -ENOMEM; | |
932 | goto out; | |
933 | } | |
1da177e4 | 934 | |
55aab8cd MN |
935 | drv->driver_name = "hvc"; |
936 | drv->name = "hvc"; | |
937 | drv->major = HVC_MAJOR; | |
938 | drv->minor_start = HVC_MINOR; | |
939 | drv->type = TTY_DRIVER_TYPE_SYSTEM; | |
940 | drv->init_termios = tty_std_termios; | |
56ce9e2b | 941 | drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS; |
55aab8cd | 942 | tty_set_operations(drv, &hvc_ops); |
1da177e4 | 943 | |
1da177e4 LT |
944 | /* Always start the kthread because there can be hotplug vty adapters |
945 | * added later. */ | |
946 | hvc_task = kthread_run(khvcd, NULL, "khvcd"); | |
947 | if (IS_ERR(hvc_task)) { | |
3e6c6f63 RR |
948 | printk(KERN_ERR "Couldn't create kthread for console.\n"); |
949 | err = PTR_ERR(hvc_task); | |
950 | goto put_tty; | |
1da177e4 LT |
951 | } |
952 | ||
3e6c6f63 RR |
953 | err = tty_register_driver(drv); |
954 | if (err) { | |
955 | printk(KERN_ERR "Couldn't register hvc console driver\n"); | |
956 | goto stop_thread; | |
957 | } | |
ef4cbee0 | 958 | |
9fef3d2d MM |
959 | /* |
960 | * Make sure tty is fully registered before allowing it to be | |
961 | * found by hvc_console_device. | |
962 | */ | |
963 | smp_mb(); | |
55aab8cd | 964 | hvc_driver = drv; |
acad9559 | 965 | return 0; |
3e6c6f63 | 966 | |
3e6c6f63 RR |
967 | stop_thread: |
968 | kthread_stop(hvc_task); | |
969 | hvc_task = NULL; | |
2571cd6a JL |
970 | put_tty: |
971 | put_tty_driver(drv); | |
3e6c6f63 RR |
972 | out: |
973 | return err; | |
1da177e4 LT |
974 | } |
975 | ||
c3ea6921 | 976 | /* This isn't particularly necessary due to this being a console driver |
320da0d2 MM |
977 | * but it is nice to be thorough. |
978 | */ | |
1da177e4 LT |
979 | static void __exit hvc_exit(void) |
980 | { | |
3e6c6f63 RR |
981 | if (hvc_driver) { |
982 | kthread_stop(hvc_task); | |
1da177e4 | 983 | |
3e6c6f63 RR |
984 | tty_unregister_driver(hvc_driver); |
985 | /* return tty_struct instances allocated in hvc_init(). */ | |
986 | put_tty_driver(hvc_driver); | |
4455b119 | 987 | unregister_console(&hvc_console); |
3e6c6f63 | 988 | } |
1da177e4 | 989 | } |
1da177e4 | 990 | module_exit(hvc_exit); |