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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> | |
30 | #include <linux/kobject.h> | |
31 | #include <linux/kthread.h> | |
32 | #include <linux/list.h> | |
33 | #include <linux/module.h> | |
34 | #include <linux/major.h> | |
35 | #include <linux/sysrq.h> | |
36 | #include <linux/tty.h> | |
37 | #include <linux/tty_flip.h> | |
38 | #include <linux/sched.h> | |
39 | #include <linux/spinlock.h> | |
40 | #include <linux/delay.h> | |
41 | #include <asm/uaccess.h> | |
42 | #include <asm/hvconsole.h> | |
43 | #include <asm/vio.h> | |
44 | ||
45 | #define HVC_MAJOR 229 | |
46 | #define HVC_MINOR 0 | |
47 | ||
48 | #define TIMEOUT (10) | |
49 | ||
50 | /* | |
51 | * Wait this long per iteration while trying to push buffered data to the | |
52 | * hypervisor before allowing the tty to complete a close operation. | |
53 | */ | |
54 | #define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */ | |
55 | ||
56 | /* | |
57 | * The Linux TTY code does not support dynamic addition of tty derived devices | |
58 | * so we need to know how many tty devices we might need when space is allocated | |
59 | * for the tty device. Since this driver supports hotplug of vty adapters we | |
60 | * need to make sure we have enough allocated. | |
61 | */ | |
62 | #define HVC_ALLOC_TTY_ADAPTERS 8 | |
63 | ||
64 | static struct tty_driver *hvc_driver; | |
65 | #ifdef CONFIG_MAGIC_SYSRQ | |
66 | static int sysrq_pressed; | |
67 | #endif | |
68 | ||
69 | #define N_OUTBUF 16 | |
70 | #define N_INBUF 16 | |
71 | ||
72 | #define __ALIGNED__ __attribute__((__aligned__(8))) | |
73 | ||
74 | struct hvc_struct { | |
75 | spinlock_t lock; | |
76 | int index; | |
77 | struct tty_struct *tty; | |
78 | unsigned int count; | |
79 | int do_wakeup; | |
80 | char outbuf[N_OUTBUF] __ALIGNED__; | |
81 | int n_outbuf; | |
82 | uint32_t vtermno; | |
83 | int irq_requested; | |
84 | int irq; | |
85 | struct list_head next; | |
86 | struct kobject kobj; /* ref count & hvc_struct lifetime */ | |
87 | struct vio_dev *vdev; | |
88 | }; | |
89 | ||
90 | /* dynamic list of hvc_struct instances */ | |
91 | static struct list_head hvc_structs = LIST_HEAD_INIT(hvc_structs); | |
92 | ||
93 | /* | |
94 | * Protect the list of hvc_struct instances from inserts and removals during | |
95 | * list traversal. | |
96 | */ | |
97 | static DEFINE_SPINLOCK(hvc_structs_lock); | |
98 | ||
99 | /* | |
100 | * Initial console vtermnos for console API usage prior to full console | |
101 | * initialization. Any vty adapter outside this range will not have usable | |
102 | * console interfaces but can still be used as a tty device. This has to be | |
103 | * static because kmalloc will not work during early console init. | |
104 | */ | |
105 | static uint32_t vtermnos[MAX_NR_HVC_CONSOLES]; | |
106 | ||
107 | /* Used for accounting purposes */ | |
108 | static int num_vterms = 0; | |
109 | ||
110 | static struct task_struct *hvc_task; | |
111 | ||
112 | /* | |
113 | * This value is used to associate a tty->index value to a hvc_struct based | |
114 | * upon order of exposure via hvc_probe(). | |
115 | */ | |
116 | static int hvc_count = -1; | |
117 | ||
118 | /* Picks up late kicks after list walk but before schedule() */ | |
119 | static int hvc_kicked; | |
120 | ||
121 | /* Wake the sleeping khvcd */ | |
122 | static void hvc_kick(void) | |
123 | { | |
124 | hvc_kicked = 1; | |
125 | wake_up_process(hvc_task); | |
126 | } | |
127 | ||
128 | /* | |
129 | * NOTE: This API isn't used if the console adapter doesn't support interrupts. | |
130 | * In this case the console is poll driven. | |
131 | */ | |
132 | static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance, struct pt_regs *regs) | |
133 | { | |
134 | hvc_kick(); | |
135 | return IRQ_HANDLED; | |
136 | } | |
137 | ||
138 | static void hvc_unthrottle(struct tty_struct *tty) | |
139 | { | |
140 | hvc_kick(); | |
141 | } | |
142 | ||
143 | /* | |
144 | * Do not call this function with either the hvc_strucst_lock or the hvc_struct | |
145 | * lock held. If successful, this function increments the kobject reference | |
146 | * count against the target hvc_struct so it should be released when finished. | |
147 | */ | |
148 | struct hvc_struct *hvc_get_by_index(int index) | |
149 | { | |
150 | struct hvc_struct *hp; | |
151 | unsigned long flags; | |
152 | ||
153 | spin_lock(&hvc_structs_lock); | |
154 | ||
155 | list_for_each_entry(hp, &hvc_structs, next) { | |
156 | spin_lock_irqsave(&hp->lock, flags); | |
157 | if (hp->index == index) { | |
158 | kobject_get(&hp->kobj); | |
159 | spin_unlock_irqrestore(&hp->lock, flags); | |
160 | spin_unlock(&hvc_structs_lock); | |
161 | return hp; | |
162 | } | |
163 | spin_unlock_irqrestore(&hp->lock, flags); | |
164 | } | |
165 | hp = NULL; | |
166 | ||
167 | spin_unlock(&hvc_structs_lock); | |
168 | return hp; | |
169 | } | |
170 | ||
171 | /* | |
172 | * The TTY interface won't be used until after the vio layer has exposed the vty | |
173 | * adapter to the kernel. | |
174 | */ | |
175 | static int hvc_open(struct tty_struct *tty, struct file * filp) | |
176 | { | |
177 | struct hvc_struct *hp; | |
178 | unsigned long flags; | |
179 | int irq = NO_IRQ; | |
180 | int rc = 0; | |
181 | struct kobject *kobjp; | |
182 | ||
183 | /* Auto increments kobject reference if found. */ | |
184 | if (!(hp = hvc_get_by_index(tty->index))) { | |
185 | printk(KERN_WARNING "hvc_console: tty open failed, no vty associated with tty.\n"); | |
186 | return -ENODEV; | |
187 | } | |
188 | ||
189 | spin_lock_irqsave(&hp->lock, flags); | |
190 | /* Check and then increment for fast path open. */ | |
191 | if (hp->count++ > 0) { | |
192 | spin_unlock_irqrestore(&hp->lock, flags); | |
193 | hvc_kick(); | |
194 | return 0; | |
195 | } /* else count == 0 */ | |
196 | ||
197 | tty->driver_data = hp; | |
198 | hp->tty = tty; | |
199 | /* Save for request_irq outside of spin_lock. */ | |
200 | irq = hp->irq; | |
201 | if (irq != NO_IRQ) | |
202 | hp->irq_requested = 1; | |
203 | ||
204 | kobjp = &hp->kobj; | |
205 | ||
206 | spin_unlock_irqrestore(&hp->lock, flags); | |
207 | /* check error, fallback to non-irq */ | |
208 | if (irq != NO_IRQ) | |
209 | rc = request_irq(irq, hvc_handle_interrupt, SA_INTERRUPT, "hvc_console", hp); | |
210 | ||
211 | /* | |
212 | * If the request_irq() fails and we return an error. The tty layer | |
213 | * will call hvc_close() after a failed open but we don't want to clean | |
214 | * up there so we'll clean up here and clear out the previously set | |
215 | * tty fields and return the kobject reference. | |
216 | */ | |
217 | if (rc) { | |
218 | spin_lock_irqsave(&hp->lock, flags); | |
219 | hp->tty = NULL; | |
220 | hp->irq_requested = 0; | |
221 | spin_unlock_irqrestore(&hp->lock, flags); | |
222 | tty->driver_data = NULL; | |
223 | kobject_put(kobjp); | |
224 | printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc); | |
225 | } | |
226 | /* Force wakeup of the polling thread */ | |
227 | hvc_kick(); | |
228 | ||
229 | return rc; | |
230 | } | |
231 | ||
232 | static void hvc_close(struct tty_struct *tty, struct file * filp) | |
233 | { | |
234 | struct hvc_struct *hp; | |
235 | struct kobject *kobjp; | |
236 | int irq = NO_IRQ; | |
237 | unsigned long flags; | |
238 | ||
239 | if (tty_hung_up_p(filp)) | |
240 | return; | |
241 | ||
242 | /* | |
243 | * No driver_data means that this close was issued after a failed | |
244 | * hvc_open by the tty layer's release_dev() function and we can just | |
245 | * exit cleanly because the kobject reference wasn't made. | |
246 | */ | |
247 | if (!tty->driver_data) | |
248 | return; | |
249 | ||
250 | hp = tty->driver_data; | |
251 | spin_lock_irqsave(&hp->lock, flags); | |
252 | ||
253 | kobjp = &hp->kobj; | |
254 | if (--hp->count == 0) { | |
255 | if (hp->irq_requested) | |
256 | irq = hp->irq; | |
257 | hp->irq_requested = 0; | |
258 | ||
259 | /* We are done with the tty pointer now. */ | |
260 | hp->tty = NULL; | |
261 | spin_unlock_irqrestore(&hp->lock, flags); | |
262 | ||
263 | /* | |
264 | * Chain calls chars_in_buffer() and returns immediately if | |
265 | * there is no buffered data otherwise sleeps on a wait queue | |
266 | * waking periodically to check chars_in_buffer(). | |
267 | */ | |
268 | tty_wait_until_sent(tty, HVC_CLOSE_WAIT); | |
269 | ||
270 | if (irq != NO_IRQ) | |
271 | free_irq(irq, hp); | |
272 | ||
273 | } else { | |
274 | if (hp->count < 0) | |
275 | printk(KERN_ERR "hvc_close %X: oops, count is %d\n", | |
276 | hp->vtermno, hp->count); | |
277 | spin_unlock_irqrestore(&hp->lock, flags); | |
278 | } | |
279 | ||
280 | kobject_put(kobjp); | |
281 | } | |
282 | ||
283 | static void hvc_hangup(struct tty_struct *tty) | |
284 | { | |
285 | struct hvc_struct *hp = tty->driver_data; | |
286 | unsigned long flags; | |
287 | int irq = NO_IRQ; | |
288 | int temp_open_count; | |
289 | struct kobject *kobjp; | |
290 | ||
291 | if (!hp) | |
292 | return; | |
293 | ||
294 | spin_lock_irqsave(&hp->lock, flags); | |
295 | ||
296 | /* | |
297 | * The N_TTY line discipline has problems such that in a close vs | |
298 | * open->hangup case this can be called after the final close so prevent | |
299 | * that from happening for now. | |
300 | */ | |
301 | if (hp->count <= 0) { | |
302 | spin_unlock_irqrestore(&hp->lock, flags); | |
303 | return; | |
304 | } | |
305 | ||
306 | kobjp = &hp->kobj; | |
307 | temp_open_count = hp->count; | |
308 | hp->count = 0; | |
309 | hp->n_outbuf = 0; | |
310 | hp->tty = NULL; | |
311 | if (hp->irq_requested) | |
312 | /* Saved for use outside of spin_lock. */ | |
313 | irq = hp->irq; | |
314 | hp->irq_requested = 0; | |
315 | spin_unlock_irqrestore(&hp->lock, flags); | |
316 | if (irq != NO_IRQ) | |
317 | free_irq(irq, hp); | |
318 | while(temp_open_count) { | |
319 | --temp_open_count; | |
320 | kobject_put(kobjp); | |
321 | } | |
322 | } | |
323 | ||
324 | /* | |
325 | * Push buffered characters whether they were just recently buffered or waiting | |
326 | * on a blocked hypervisor. Call this function with hp->lock held. | |
327 | */ | |
328 | static void hvc_push(struct hvc_struct *hp) | |
329 | { | |
330 | int n; | |
331 | ||
332 | n = hvc_put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); | |
333 | if (n <= 0) { | |
334 | if (n == 0) | |
335 | return; | |
336 | /* throw away output on error; this happens when | |
337 | there is no session connected to the vterm. */ | |
338 | hp->n_outbuf = 0; | |
339 | } else | |
340 | hp->n_outbuf -= n; | |
341 | if (hp->n_outbuf > 0) | |
342 | memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf); | |
343 | else | |
344 | hp->do_wakeup = 1; | |
345 | } | |
346 | ||
347 | static inline int __hvc_write_kernel(struct hvc_struct *hp, | |
348 | const unsigned char *buf, int count) | |
349 | { | |
350 | unsigned long flags; | |
351 | int rsize, written = 0; | |
352 | ||
353 | spin_lock_irqsave(&hp->lock, flags); | |
354 | ||
355 | /* Push pending writes */ | |
356 | if (hp->n_outbuf > 0) | |
357 | hvc_push(hp); | |
358 | ||
359 | while (count > 0 && (rsize = N_OUTBUF - hp->n_outbuf) > 0) { | |
360 | if (rsize > count) | |
361 | rsize = count; | |
362 | memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); | |
363 | count -= rsize; | |
364 | buf += rsize; | |
365 | hp->n_outbuf += rsize; | |
366 | written += rsize; | |
367 | hvc_push(hp); | |
368 | } | |
369 | spin_unlock_irqrestore(&hp->lock, flags); | |
370 | ||
371 | return written; | |
372 | } | |
373 | static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) | |
374 | { | |
375 | struct hvc_struct *hp = tty->driver_data; | |
376 | int written; | |
377 | ||
378 | /* This write was probably executed during a tty close. */ | |
379 | if (!hp) | |
380 | return -EPIPE; | |
381 | ||
382 | if (hp->count <= 0) | |
383 | return -EIO; | |
384 | ||
385 | written = __hvc_write_kernel(hp, buf, count); | |
386 | ||
387 | /* | |
388 | * Racy, but harmless, kick thread if there is still pending data. | |
389 | * There really is nothing wrong with kicking the thread, even if there | |
390 | * is no buffered data. | |
391 | */ | |
392 | if (hp->n_outbuf) | |
393 | hvc_kick(); | |
394 | ||
395 | return written; | |
396 | } | |
397 | ||
398 | /* | |
399 | * This is actually a contract between the driver and the tty layer outlining | |
400 | * how much write room the driver can guarentee will be sent OR BUFFERED. This | |
401 | * driver MUST honor the return value. | |
402 | */ | |
403 | static int hvc_write_room(struct tty_struct *tty) | |
404 | { | |
405 | struct hvc_struct *hp = tty->driver_data; | |
406 | ||
407 | if (!hp) | |
408 | return -1; | |
409 | ||
410 | return N_OUTBUF - hp->n_outbuf; | |
411 | } | |
412 | ||
413 | static int hvc_chars_in_buffer(struct tty_struct *tty) | |
414 | { | |
415 | struct hvc_struct *hp = tty->driver_data; | |
416 | ||
417 | if (!hp) | |
418 | return -1; | |
419 | return hp->n_outbuf; | |
420 | } | |
421 | ||
422 | #define HVC_POLL_READ 0x00000001 | |
423 | #define HVC_POLL_WRITE 0x00000002 | |
424 | #define HVC_POLL_QUICK 0x00000004 | |
425 | ||
426 | static int hvc_poll(struct hvc_struct *hp) | |
427 | { | |
428 | struct tty_struct *tty; | |
429 | int i, n, poll_mask = 0; | |
430 | char buf[N_INBUF] __ALIGNED__; | |
431 | unsigned long flags; | |
432 | int read_total = 0; | |
433 | ||
434 | spin_lock_irqsave(&hp->lock, flags); | |
435 | ||
436 | /* Push pending writes */ | |
437 | if (hp->n_outbuf > 0) | |
438 | hvc_push(hp); | |
439 | /* Reschedule us if still some write pending */ | |
440 | if (hp->n_outbuf > 0) | |
441 | poll_mask |= HVC_POLL_WRITE; | |
442 | ||
443 | /* No tty attached, just skip */ | |
444 | tty = hp->tty; | |
445 | if (tty == NULL) | |
446 | goto bail; | |
447 | ||
448 | /* Now check if we can get data (are we throttled ?) */ | |
449 | if (test_bit(TTY_THROTTLED, &tty->flags)) | |
450 | goto throttled; | |
451 | ||
452 | /* If we aren't interrupt driven and aren't throttled, we always | |
453 | * request a reschedule | |
454 | */ | |
455 | if (hp->irq == NO_IRQ) | |
456 | poll_mask |= HVC_POLL_READ; | |
457 | ||
458 | /* Read data if any */ | |
459 | for (;;) { | |
460 | int count = N_INBUF; | |
461 | if (count > (TTY_FLIPBUF_SIZE - tty->flip.count)) | |
462 | count = TTY_FLIPBUF_SIZE - tty->flip.count; | |
463 | ||
464 | /* If flip is full, just reschedule a later read */ | |
465 | if (count == 0) { | |
466 | poll_mask |= HVC_POLL_READ; | |
467 | break; | |
468 | } | |
469 | ||
470 | n = hvc_get_chars(hp->vtermno, buf, count); | |
471 | if (n <= 0) { | |
472 | /* Hangup the tty when disconnected from host */ | |
473 | if (n == -EPIPE) { | |
474 | spin_unlock_irqrestore(&hp->lock, flags); | |
475 | tty_hangup(tty); | |
476 | spin_lock_irqsave(&hp->lock, flags); | |
477 | } | |
478 | break; | |
479 | } | |
480 | for (i = 0; i < n; ++i) { | |
481 | #ifdef CONFIG_MAGIC_SYSRQ | |
482 | /* Handle the SysRq Hack */ | |
483 | if (buf[i] == '\x0f') { /* ^O -- should support a sequence */ | |
484 | sysrq_pressed = 1; | |
485 | continue; | |
486 | } else if (sysrq_pressed) { | |
487 | handle_sysrq(buf[i], NULL, tty); | |
488 | sysrq_pressed = 0; | |
489 | continue; | |
490 | } | |
491 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
492 | tty_insert_flip_char(tty, buf[i], 0); | |
493 | } | |
494 | ||
495 | if (tty->flip.count) | |
496 | tty_schedule_flip(tty); | |
497 | ||
498 | /* | |
499 | * Account for the total amount read in one loop, and if above | |
500 | * 64 bytes, we do a quick schedule loop to let the tty grok the | |
501 | * data and eventually throttle us. | |
502 | */ | |
503 | read_total += n; | |
504 | if (read_total >= 64) { | |
505 | poll_mask |= HVC_POLL_QUICK; | |
506 | break; | |
507 | } | |
508 | } | |
509 | throttled: | |
510 | /* Wakeup write queue if necessary */ | |
511 | if (hp->do_wakeup) { | |
512 | hp->do_wakeup = 0; | |
513 | tty_wakeup(tty); | |
514 | } | |
515 | bail: | |
516 | spin_unlock_irqrestore(&hp->lock, flags); | |
517 | ||
518 | return poll_mask; | |
519 | } | |
520 | ||
521 | #if defined(CONFIG_XMON) && defined(CONFIG_SMP) | |
522 | extern cpumask_t cpus_in_xmon; | |
523 | #else | |
524 | static const cpumask_t cpus_in_xmon = CPU_MASK_NONE; | |
525 | #endif | |
526 | ||
527 | /* | |
528 | * This kthread is either polling or interrupt driven. This is determined by | |
529 | * calling hvc_poll() who determines whether a console adapter support | |
530 | * interrupts. | |
531 | */ | |
532 | int khvcd(void *unused) | |
533 | { | |
534 | int poll_mask; | |
535 | struct hvc_struct *hp; | |
536 | ||
537 | __set_current_state(TASK_RUNNING); | |
538 | do { | |
539 | poll_mask = 0; | |
540 | hvc_kicked = 0; | |
541 | wmb(); | |
542 | if (cpus_empty(cpus_in_xmon)) { | |
543 | spin_lock(&hvc_structs_lock); | |
544 | list_for_each_entry(hp, &hvc_structs, next) { | |
545 | /*hp = list_entry(node, struct hvc_struct, * next); */ | |
546 | poll_mask |= hvc_poll(hp); | |
547 | } | |
548 | spin_unlock(&hvc_structs_lock); | |
549 | } else | |
550 | poll_mask |= HVC_POLL_READ; | |
551 | if (hvc_kicked) | |
552 | continue; | |
553 | if (poll_mask & HVC_POLL_QUICK) { | |
554 | yield(); | |
555 | continue; | |
556 | } | |
557 | set_current_state(TASK_INTERRUPTIBLE); | |
558 | if (!hvc_kicked) { | |
559 | if (poll_mask == 0) | |
560 | schedule(); | |
561 | else | |
562 | msleep_interruptible(TIMEOUT); | |
563 | } | |
564 | __set_current_state(TASK_RUNNING); | |
565 | } while (!kthread_should_stop()); | |
566 | ||
567 | return 0; | |
568 | } | |
569 | ||
570 | static struct tty_operations hvc_ops = { | |
571 | .open = hvc_open, | |
572 | .close = hvc_close, | |
573 | .write = hvc_write, | |
574 | .hangup = hvc_hangup, | |
575 | .unthrottle = hvc_unthrottle, | |
576 | .write_room = hvc_write_room, | |
577 | .chars_in_buffer = hvc_chars_in_buffer, | |
578 | }; | |
579 | ||
580 | char hvc_driver_name[] = "hvc_console"; | |
581 | ||
582 | static struct vio_device_id hvc_driver_table[] __devinitdata= { | |
583 | {"serial", "hvterm1"}, | |
584 | { NULL, } | |
585 | }; | |
586 | MODULE_DEVICE_TABLE(vio, hvc_driver_table); | |
587 | ||
588 | /* callback when the kboject ref count reaches zero. */ | |
589 | static void destroy_hvc_struct(struct kobject *kobj) | |
590 | { | |
591 | struct hvc_struct *hp = container_of(kobj, struct hvc_struct, kobj); | |
592 | unsigned long flags; | |
593 | ||
594 | spin_lock(&hvc_structs_lock); | |
595 | ||
596 | spin_lock_irqsave(&hp->lock, flags); | |
597 | list_del(&(hp->next)); | |
598 | spin_unlock_irqrestore(&hp->lock, flags); | |
599 | ||
600 | spin_unlock(&hvc_structs_lock); | |
601 | ||
602 | kfree(hp); | |
603 | } | |
604 | ||
605 | static struct kobj_type hvc_kobj_type = { | |
606 | .release = destroy_hvc_struct, | |
607 | }; | |
608 | ||
609 | static int __devinit hvc_probe( | |
610 | struct vio_dev *dev, | |
611 | const struct vio_device_id *id) | |
612 | { | |
613 | struct hvc_struct *hp; | |
614 | ||
615 | /* probed with invalid parameters. */ | |
616 | if (!dev || !id) | |
617 | return -EPERM; | |
618 | ||
619 | hp = kmalloc(sizeof(*hp), GFP_KERNEL); | |
620 | if (!hp) | |
621 | return -ENOMEM; | |
622 | ||
623 | memset(hp, 0x00, sizeof(*hp)); | |
624 | hp->vtermno = dev->unit_address; | |
625 | hp->vdev = dev; | |
626 | hp->vdev->dev.driver_data = hp; | |
627 | hp->irq = dev->irq; | |
628 | ||
629 | kobject_init(&hp->kobj); | |
630 | hp->kobj.ktype = &hvc_kobj_type; | |
631 | ||
632 | spin_lock_init(&hp->lock); | |
633 | spin_lock(&hvc_structs_lock); | |
634 | hp->index = ++hvc_count; | |
635 | list_add_tail(&(hp->next), &hvc_structs); | |
636 | spin_unlock(&hvc_structs_lock); | |
637 | ||
638 | return 0; | |
639 | } | |
640 | ||
641 | static int __devexit hvc_remove(struct vio_dev *dev) | |
642 | { | |
643 | struct hvc_struct *hp = dev->dev.driver_data; | |
644 | unsigned long flags; | |
645 | struct kobject *kobjp; | |
646 | struct tty_struct *tty; | |
647 | ||
648 | spin_lock_irqsave(&hp->lock, flags); | |
649 | tty = hp->tty; | |
650 | kobjp = &hp->kobj; | |
651 | ||
652 | if (hp->index < MAX_NR_HVC_CONSOLES) | |
653 | vtermnos[hp->index] = -1; | |
654 | ||
655 | /* Don't whack hp->irq because tty_hangup() will need to free the irq. */ | |
656 | ||
657 | spin_unlock_irqrestore(&hp->lock, flags); | |
658 | ||
659 | /* | |
660 | * We 'put' the instance that was grabbed when the kobject instance | |
661 | * was intialized using kobject_init(). Let the last holder of this | |
662 | * kobject cause it to be removed, which will probably be the tty_hangup | |
663 | * below. | |
664 | */ | |
665 | kobject_put(kobjp); | |
666 | ||
667 | /* | |
668 | * This function call will auto chain call hvc_hangup. The tty should | |
669 | * always be valid at this time unless a simultaneous tty close already | |
670 | * cleaned up the hvc_struct. | |
671 | */ | |
672 | if (tty) | |
673 | tty_hangup(tty); | |
674 | return 0; | |
675 | } | |
676 | ||
677 | static struct vio_driver hvc_vio_driver = { | |
678 | .name = hvc_driver_name, | |
679 | .id_table = hvc_driver_table, | |
680 | .probe = hvc_probe, | |
681 | .remove = hvc_remove, | |
682 | }; | |
683 | ||
684 | /* Driver initialization. Follow console initialization. This is where the TTY | |
685 | * interfaces start to become available. */ | |
686 | int __init hvc_init(void) | |
687 | { | |
688 | int rc; | |
689 | ||
690 | /* We need more than num_vterms adapters due to hotplug additions. */ | |
691 | hvc_driver = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS); | |
692 | /* hvc_driver = alloc_tty_driver(num_vterms); */ | |
693 | if (!hvc_driver) | |
694 | return -ENOMEM; | |
695 | ||
696 | hvc_driver->owner = THIS_MODULE; | |
697 | hvc_driver->devfs_name = "hvc/"; | |
698 | hvc_driver->driver_name = "hvc"; | |
699 | hvc_driver->name = "hvc"; | |
700 | hvc_driver->major = HVC_MAJOR; | |
701 | hvc_driver->minor_start = HVC_MINOR; | |
702 | hvc_driver->type = TTY_DRIVER_TYPE_SYSTEM; | |
703 | hvc_driver->init_termios = tty_std_termios; | |
704 | hvc_driver->flags = TTY_DRIVER_REAL_RAW; | |
705 | tty_set_operations(hvc_driver, &hvc_ops); | |
706 | ||
707 | if (tty_register_driver(hvc_driver)) | |
708 | panic("Couldn't register hvc console driver\n"); | |
709 | ||
710 | /* Always start the kthread because there can be hotplug vty adapters | |
711 | * added later. */ | |
712 | hvc_task = kthread_run(khvcd, NULL, "khvcd"); | |
713 | if (IS_ERR(hvc_task)) { | |
714 | panic("Couldn't create kthread for console.\n"); | |
715 | put_tty_driver(hvc_driver); | |
716 | return -EIO; | |
717 | } | |
718 | ||
719 | /* Register as a vio device to receive callbacks */ | |
720 | rc = vio_register_driver(&hvc_vio_driver); | |
721 | ||
722 | return rc; | |
723 | } | |
724 | ||
725 | /* This isn't particularily necessary due to this being a console driver but it | |
726 | * is nice to be thorough */ | |
727 | static void __exit hvc_exit(void) | |
728 | { | |
729 | kthread_stop(hvc_task); | |
730 | ||
731 | vio_unregister_driver(&hvc_vio_driver); | |
732 | tty_unregister_driver(hvc_driver); | |
733 | /* return tty_struct instances allocated in hvc_init(). */ | |
734 | put_tty_driver(hvc_driver); | |
735 | } | |
736 | ||
737 | /* | |
738 | * Console APIs, NOT TTY. These APIs are available immediately when | |
739 | * hvc_console_setup() finds adapters. | |
740 | */ | |
741 | ||
742 | /* | |
743 | * hvc_instantiate() is an early console discovery method which locates consoles | |
744 | * prior to the vio subsystem discovering them. Hotplugged vty adapters do NOT | |
745 | * get an hvc_instantiate() callback since the appear after early console init. | |
746 | */ | |
747 | int hvc_instantiate(uint32_t vtermno, int index) | |
748 | { | |
749 | if (index < 0 || index >= MAX_NR_HVC_CONSOLES) | |
750 | return -1; | |
751 | ||
752 | if (vtermnos[index] != -1) | |
753 | return -1; | |
754 | ||
755 | vtermnos[index] = vtermno; | |
756 | return 0; | |
757 | } | |
758 | ||
759 | void hvc_console_print(struct console *co, const char *b, unsigned count) | |
760 | { | |
761 | char c[16] __ALIGNED__; | |
762 | unsigned i = 0, n = 0; | |
763 | int r, donecr = 0; | |
764 | ||
765 | /* Console access attempt outside of acceptable console range. */ | |
766 | if (co->index >= MAX_NR_HVC_CONSOLES) | |
767 | return; | |
768 | ||
769 | /* This console adapter was removed so it is not useable. */ | |
770 | if (vtermnos[co->index] < 0) | |
771 | return; | |
772 | ||
773 | while (count > 0 || i > 0) { | |
774 | if (count > 0 && i < sizeof(c)) { | |
775 | if (b[n] == '\n' && !donecr) { | |
776 | c[i++] = '\r'; | |
777 | donecr = 1; | |
778 | } else { | |
779 | c[i++] = b[n++]; | |
780 | donecr = 0; | |
781 | --count; | |
782 | } | |
783 | } else { | |
784 | r = hvc_put_chars(vtermnos[co->index], c, i); | |
785 | if (r < 0) { | |
786 | /* throw away chars on error */ | |
787 | i = 0; | |
788 | } else if (r > 0) { | |
789 | i -= r; | |
790 | if (i > 0) | |
791 | memmove(c, c+r, i); | |
792 | } | |
793 | } | |
794 | } | |
795 | } | |
796 | ||
797 | static struct tty_driver *hvc_console_device(struct console *c, int *index) | |
798 | { | |
799 | *index = c->index; | |
800 | return hvc_driver; | |
801 | } | |
802 | ||
803 | static int __init hvc_console_setup(struct console *co, char *options) | |
804 | { | |
805 | return 0; | |
806 | } | |
807 | ||
808 | struct console hvc_con_driver = { | |
809 | .name = "hvc", | |
810 | .write = hvc_console_print, | |
811 | .device = hvc_console_device, | |
812 | .setup = hvc_console_setup, | |
813 | .flags = CON_PRINTBUFFER, | |
814 | .index = -1, | |
815 | }; | |
816 | ||
817 | /* Early console initialization. Preceeds driver initialization. */ | |
818 | static int __init hvc_console_init(void) | |
819 | { | |
820 | int i; | |
821 | ||
822 | for (i=0; i<MAX_NR_HVC_CONSOLES; i++) | |
823 | vtermnos[i] = -1; | |
824 | num_vterms = hvc_find_vtys(); | |
825 | register_console(&hvc_con_driver); | |
826 | return 0; | |
827 | } | |
828 | console_initcall(hvc_console_init); | |
829 | ||
830 | module_init(hvc_init); | |
831 | module_exit(hvc_exit); |