blob: 31980994feadee917603b02ed9b5ae7e59a8feaa [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Milton Millere51d8c92005-07-07 17:56:21 -070025#include <linux/config.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/console.h>
27#include <linux/cpumask.h>
28#include <linux/init.h>
29#include <linux/kbd_kern.h>
30#include <linux/kernel.h>
31#include <linux/kobject.h>
32#include <linux/kthread.h>
33#include <linux/list.h>
34#include <linux/module.h>
35#include <linux/major.h>
36#include <linux/sysrq.h>
37#include <linux/tty.h>
38#include <linux/tty_flip.h>
39#include <linux/sched.h>
40#include <linux/spinlock.h>
41#include <linux/delay.h>
42#include <asm/uaccess.h>
43#include <asm/hvconsole.h>
44#include <asm/vio.h>
45
46#define HVC_MAJOR 229
47#define HVC_MINOR 0
48
49#define TIMEOUT (10)
50
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/*
58 * The Linux TTY code does not support dynamic addition of tty derived devices
59 * so we need to know how many tty devices we might need when space is allocated
60 * for the tty device. Since this driver supports hotplug of vty adapters we
61 * need to make sure we have enough allocated.
62 */
63#define HVC_ALLOC_TTY_ADAPTERS 8
64
Linus Torvalds1da177e2005-04-16 15:20:36 -070065#define N_OUTBUF 16
66#define N_INBUF 16
67
68#define __ALIGNED__ __attribute__((__aligned__(8)))
69
Milton Miller837dcfa2005-07-07 17:56:16 -070070static struct tty_driver *hvc_driver;
71static struct task_struct *hvc_task;
72
73/* Picks up late kicks after list walk but before schedule() */
74static int hvc_kicked;
75
76#ifdef CONFIG_MAGIC_SYSRQ
77static int sysrq_pressed;
78#endif
79
Linus Torvalds1da177e2005-04-16 15:20:36 -070080struct hvc_struct {
81 spinlock_t lock;
82 int index;
83 struct tty_struct *tty;
84 unsigned int count;
85 int do_wakeup;
86 char outbuf[N_OUTBUF] __ALIGNED__;
87 int n_outbuf;
88 uint32_t vtermno;
89 int irq_requested;
90 int irq;
91 struct list_head next;
92 struct kobject kobj; /* ref count & hvc_struct lifetime */
93 struct vio_dev *vdev;
94};
95
96/* dynamic list of hvc_struct instances */
97static struct list_head hvc_structs = LIST_HEAD_INIT(hvc_structs);
98
99/*
100 * Protect the list of hvc_struct instances from inserts and removals during
101 * list traversal.
102 */
103static DEFINE_SPINLOCK(hvc_structs_lock);
104
105/*
Milton Miller6f248082005-07-07 17:56:17 -0700106 * This value is used to assign a tty->index value to a hvc_struct based
107 * upon order of exposure via hvc_probe(), when we can not match it to
108 * a console canidate registered with hvc_instantiate().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 */
Milton Miller6f248082005-07-07 17:56:17 -0700110static int last_hvc = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112/*
113 * Do not call this function with either the hvc_strucst_lock or the hvc_struct
114 * lock held. If successful, this function increments the kobject reference
115 * count against the target hvc_struct so it should be released when finished.
116 */
117struct hvc_struct *hvc_get_by_index(int index)
118{
119 struct hvc_struct *hp;
120 unsigned long flags;
121
122 spin_lock(&hvc_structs_lock);
123
124 list_for_each_entry(hp, &hvc_structs, next) {
125 spin_lock_irqsave(&hp->lock, flags);
126 if (hp->index == index) {
127 kobject_get(&hp->kobj);
128 spin_unlock_irqrestore(&hp->lock, flags);
129 spin_unlock(&hvc_structs_lock);
130 return hp;
131 }
132 spin_unlock_irqrestore(&hp->lock, flags);
133 }
134 hp = NULL;
135
136 spin_unlock(&hvc_structs_lock);
137 return hp;
138}
139
Milton Miller837dcfa2005-07-07 17:56:16 -0700140
141/*
142 * Initial console vtermnos for console API usage prior to full console
143 * initialization. Any vty adapter outside this range will not have usable
144 * console interfaces but can still be used as a tty device. This has to be
145 * static because kmalloc will not work during early console init.
146 */
147static uint32_t vtermnos[MAX_NR_HVC_CONSOLES];
148
149/* Used for accounting purposes */
150static int num_vterms = 0;
151
152/*
153 * Console APIs, NOT TTY. These APIs are available immediately when
154 * hvc_console_setup() finds adapters.
155 */
156
157void hvc_console_print(struct console *co, const char *b, unsigned count)
158{
159 char c[16] __ALIGNED__;
160 unsigned i = 0, n = 0;
161 int r, donecr = 0;
162
163 /* Console access attempt outside of acceptable console range. */
164 if (co->index >= MAX_NR_HVC_CONSOLES)
165 return;
166
167 /* This console adapter was removed so it is not useable. */
168 if (vtermnos[co->index] < 0)
169 return;
170
171 while (count > 0 || i > 0) {
172 if (count > 0 && i < sizeof(c)) {
173 if (b[n] == '\n' && !donecr) {
174 c[i++] = '\r';
175 donecr = 1;
176 } else {
177 c[i++] = b[n++];
178 donecr = 0;
179 --count;
180 }
181 } else {
182 r = hvc_put_chars(vtermnos[co->index], c, i);
183 if (r < 0) {
184 /* throw away chars on error */
185 i = 0;
186 } else if (r > 0) {
187 i -= r;
188 if (i > 0)
189 memmove(c, c+r, i);
190 }
191 }
192 }
193}
194
195static struct tty_driver *hvc_console_device(struct console *c, int *index)
196{
197 *index = c->index;
198 return hvc_driver;
199}
200
201static int __init hvc_console_setup(struct console *co, char *options)
202{
203 return 0;
204}
205
206struct console hvc_con_driver = {
207 .name = "hvc",
208 .write = hvc_console_print,
209 .device = hvc_console_device,
210 .setup = hvc_console_setup,
211 .flags = CON_PRINTBUFFER,
212 .index = -1,
213};
214
215/* Early console initialization. Preceeds driver initialization. */
216static int __init hvc_console_init(void)
217{
218 int i;
219
220 for (i=0; i<MAX_NR_HVC_CONSOLES; i++)
221 vtermnos[i] = -1;
222 num_vterms = hvc_find_vtys();
223 register_console(&hvc_con_driver);
224 return 0;
225}
226console_initcall(hvc_console_init);
227
228/*
Milton Miller6f248082005-07-07 17:56:17 -0700229 * hvc_instantiate() is an early console discovery method which locates
230 * consoles * prior to the vio subsystem discovering them. Hotplugged
231 * vty adapters do NOT get an hvc_instantiate() callback since they
232 * appear after early console init.
Milton Miller837dcfa2005-07-07 17:56:16 -0700233 */
234int hvc_instantiate(uint32_t vtermno, int index)
235{
236 if (index < 0 || index >= MAX_NR_HVC_CONSOLES)
237 return -1;
238
239 if (vtermnos[index] != -1)
240 return -1;
241
242 vtermnos[index] = vtermno;
Milton Miller6f248082005-07-07 17:56:17 -0700243
244 /* reserve all indices upto and including this index */
245 if (last_hvc < index)
246 last_hvc = index;
247
Milton Miller837dcfa2005-07-07 17:56:16 -0700248 return 0;
249}
250
251/* Wake the sleeping khvcd */
252static void hvc_kick(void)
253{
254 hvc_kicked = 1;
255 wake_up_process(hvc_task);
256}
257
Milton Miller8b67f8c2005-07-07 17:56:18 -0700258static int hvc_poll(struct hvc_struct *hp);
259
Milton Miller837dcfa2005-07-07 17:56:16 -0700260/*
261 * NOTE: This API isn't used if the console adapter doesn't support interrupts.
262 * In this case the console is poll driven.
263 */
264static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance, struct pt_regs *regs)
265{
Milton Miller8b67f8c2005-07-07 17:56:18 -0700266 /* if hvc_poll request a repoll, then kick the hvcd thread */
267 if (hvc_poll(dev_instance))
268 hvc_kick();
Milton Miller837dcfa2005-07-07 17:56:16 -0700269 return IRQ_HANDLED;
270}
271
272static void hvc_unthrottle(struct tty_struct *tty)
273{
274 hvc_kick();
275}
276
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277/*
278 * The TTY interface won't be used until after the vio layer has exposed the vty
279 * adapter to the kernel.
280 */
281static int hvc_open(struct tty_struct *tty, struct file * filp)
282{
283 struct hvc_struct *hp;
284 unsigned long flags;
285 int irq = NO_IRQ;
286 int rc = 0;
287 struct kobject *kobjp;
288
289 /* Auto increments kobject reference if found. */
290 if (!(hp = hvc_get_by_index(tty->index))) {
291 printk(KERN_WARNING "hvc_console: tty open failed, no vty associated with tty.\n");
292 return -ENODEV;
293 }
294
295 spin_lock_irqsave(&hp->lock, flags);
296 /* Check and then increment for fast path open. */
297 if (hp->count++ > 0) {
298 spin_unlock_irqrestore(&hp->lock, flags);
299 hvc_kick();
300 return 0;
301 } /* else count == 0 */
302
303 tty->driver_data = hp;
304 hp->tty = tty;
305 /* Save for request_irq outside of spin_lock. */
306 irq = hp->irq;
307 if (irq != NO_IRQ)
308 hp->irq_requested = 1;
309
310 kobjp = &hp->kobj;
311
312 spin_unlock_irqrestore(&hp->lock, flags);
313 /* check error, fallback to non-irq */
314 if (irq != NO_IRQ)
315 rc = request_irq(irq, hvc_handle_interrupt, SA_INTERRUPT, "hvc_console", hp);
316
317 /*
318 * If the request_irq() fails and we return an error. The tty layer
319 * will call hvc_close() after a failed open but we don't want to clean
320 * up there so we'll clean up here and clear out the previously set
321 * tty fields and return the kobject reference.
322 */
323 if (rc) {
324 spin_lock_irqsave(&hp->lock, flags);
325 hp->tty = NULL;
326 hp->irq_requested = 0;
327 spin_unlock_irqrestore(&hp->lock, flags);
328 tty->driver_data = NULL;
329 kobject_put(kobjp);
330 printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc);
331 }
332 /* Force wakeup of the polling thread */
333 hvc_kick();
334
335 return rc;
336}
337
338static void hvc_close(struct tty_struct *tty, struct file * filp)
339{
340 struct hvc_struct *hp;
341 struct kobject *kobjp;
342 int irq = NO_IRQ;
343 unsigned long flags;
344
345 if (tty_hung_up_p(filp))
346 return;
347
348 /*
349 * No driver_data means that this close was issued after a failed
350 * hvc_open by the tty layer's release_dev() function and we can just
351 * exit cleanly because the kobject reference wasn't made.
352 */
353 if (!tty->driver_data)
354 return;
355
356 hp = tty->driver_data;
357 spin_lock_irqsave(&hp->lock, flags);
358
359 kobjp = &hp->kobj;
360 if (--hp->count == 0) {
361 if (hp->irq_requested)
362 irq = hp->irq;
363 hp->irq_requested = 0;
364
365 /* We are done with the tty pointer now. */
366 hp->tty = NULL;
367 spin_unlock_irqrestore(&hp->lock, flags);
368
369 /*
370 * Chain calls chars_in_buffer() and returns immediately if
371 * there is no buffered data otherwise sleeps on a wait queue
372 * waking periodically to check chars_in_buffer().
373 */
374 tty_wait_until_sent(tty, HVC_CLOSE_WAIT);
375
376 if (irq != NO_IRQ)
377 free_irq(irq, hp);
378
379 } else {
380 if (hp->count < 0)
381 printk(KERN_ERR "hvc_close %X: oops, count is %d\n",
382 hp->vtermno, hp->count);
383 spin_unlock_irqrestore(&hp->lock, flags);
384 }
385
386 kobject_put(kobjp);
387}
388
389static void hvc_hangup(struct tty_struct *tty)
390{
391 struct hvc_struct *hp = tty->driver_data;
392 unsigned long flags;
393 int irq = NO_IRQ;
394 int temp_open_count;
395 struct kobject *kobjp;
396
397 if (!hp)
398 return;
399
400 spin_lock_irqsave(&hp->lock, flags);
401
402 /*
403 * The N_TTY line discipline has problems such that in a close vs
404 * open->hangup case this can be called after the final close so prevent
405 * that from happening for now.
406 */
407 if (hp->count <= 0) {
408 spin_unlock_irqrestore(&hp->lock, flags);
409 return;
410 }
411
412 kobjp = &hp->kobj;
413 temp_open_count = hp->count;
414 hp->count = 0;
415 hp->n_outbuf = 0;
416 hp->tty = NULL;
417 if (hp->irq_requested)
418 /* Saved for use outside of spin_lock. */
419 irq = hp->irq;
420 hp->irq_requested = 0;
421 spin_unlock_irqrestore(&hp->lock, flags);
422 if (irq != NO_IRQ)
423 free_irq(irq, hp);
424 while(temp_open_count) {
425 --temp_open_count;
426 kobject_put(kobjp);
427 }
428}
429
430/*
431 * Push buffered characters whether they were just recently buffered or waiting
432 * on a blocked hypervisor. Call this function with hp->lock held.
433 */
434static void hvc_push(struct hvc_struct *hp)
435{
436 int n;
437
438 n = hvc_put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf);
439 if (n <= 0) {
440 if (n == 0)
441 return;
442 /* throw away output on error; this happens when
443 there is no session connected to the vterm. */
444 hp->n_outbuf = 0;
445 } else
446 hp->n_outbuf -= n;
447 if (hp->n_outbuf > 0)
448 memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf);
449 else
450 hp->do_wakeup = 1;
451}
452
453static inline int __hvc_write_kernel(struct hvc_struct *hp,
454 const unsigned char *buf, int count)
455{
456 unsigned long flags;
457 int rsize, written = 0;
458
459 spin_lock_irqsave(&hp->lock, flags);
460
461 /* Push pending writes */
462 if (hp->n_outbuf > 0)
463 hvc_push(hp);
464
465 while (count > 0 && (rsize = N_OUTBUF - hp->n_outbuf) > 0) {
466 if (rsize > count)
467 rsize = count;
468 memcpy(hp->outbuf + hp->n_outbuf, buf, rsize);
469 count -= rsize;
470 buf += rsize;
471 hp->n_outbuf += rsize;
472 written += rsize;
473 hvc_push(hp);
474 }
475 spin_unlock_irqrestore(&hp->lock, flags);
476
477 return written;
478}
479static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count)
480{
481 struct hvc_struct *hp = tty->driver_data;
482 int written;
483
484 /* This write was probably executed during a tty close. */
485 if (!hp)
486 return -EPIPE;
487
488 if (hp->count <= 0)
489 return -EIO;
490
491 written = __hvc_write_kernel(hp, buf, count);
492
493 /*
494 * Racy, but harmless, kick thread if there is still pending data.
495 * There really is nothing wrong with kicking the thread, even if there
496 * is no buffered data.
497 */
498 if (hp->n_outbuf)
499 hvc_kick();
500
501 return written;
502}
503
504/*
505 * This is actually a contract between the driver and the tty layer outlining
506 * how much write room the driver can guarentee will be sent OR BUFFERED. This
507 * driver MUST honor the return value.
508 */
509static int hvc_write_room(struct tty_struct *tty)
510{
511 struct hvc_struct *hp = tty->driver_data;
512
513 if (!hp)
514 return -1;
515
516 return N_OUTBUF - hp->n_outbuf;
517}
518
519static int hvc_chars_in_buffer(struct tty_struct *tty)
520{
521 struct hvc_struct *hp = tty->driver_data;
522
523 if (!hp)
524 return -1;
525 return hp->n_outbuf;
526}
527
528#define HVC_POLL_READ 0x00000001
529#define HVC_POLL_WRITE 0x00000002
530#define HVC_POLL_QUICK 0x00000004
531
532static int hvc_poll(struct hvc_struct *hp)
533{
534 struct tty_struct *tty;
535 int i, n, poll_mask = 0;
536 char buf[N_INBUF] __ALIGNED__;
537 unsigned long flags;
538 int read_total = 0;
539
540 spin_lock_irqsave(&hp->lock, flags);
541
542 /* Push pending writes */
543 if (hp->n_outbuf > 0)
544 hvc_push(hp);
545 /* Reschedule us if still some write pending */
546 if (hp->n_outbuf > 0)
547 poll_mask |= HVC_POLL_WRITE;
548
549 /* No tty attached, just skip */
550 tty = hp->tty;
551 if (tty == NULL)
552 goto bail;
553
554 /* Now check if we can get data (are we throttled ?) */
555 if (test_bit(TTY_THROTTLED, &tty->flags))
556 goto throttled;
557
558 /* If we aren't interrupt driven and aren't throttled, we always
559 * request a reschedule
560 */
561 if (hp->irq == NO_IRQ)
562 poll_mask |= HVC_POLL_READ;
563
564 /* Read data if any */
565 for (;;) {
566 int count = N_INBUF;
567 if (count > (TTY_FLIPBUF_SIZE - tty->flip.count))
568 count = TTY_FLIPBUF_SIZE - tty->flip.count;
569
570 /* If flip is full, just reschedule a later read */
571 if (count == 0) {
572 poll_mask |= HVC_POLL_READ;
573 break;
574 }
575
576 n = hvc_get_chars(hp->vtermno, buf, count);
577 if (n <= 0) {
578 /* Hangup the tty when disconnected from host */
579 if (n == -EPIPE) {
580 spin_unlock_irqrestore(&hp->lock, flags);
581 tty_hangup(tty);
582 spin_lock_irqsave(&hp->lock, flags);
583 }
584 break;
585 }
586 for (i = 0; i < n; ++i) {
587#ifdef CONFIG_MAGIC_SYSRQ
Milton Miller2b9e0ba2005-07-07 17:56:19 -0700588 if (hp->index == hvc_con_driver.index) {
589 /* Handle the SysRq Hack */
590 /* XXX should support a sequence */
591 if (buf[i] == '\x0f') { /* ^O */
592 sysrq_pressed = 1;
593 continue;
594 } else if (sysrq_pressed) {
595 handle_sysrq(buf[i], NULL, tty);
596 sysrq_pressed = 0;
597 continue;
598 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 }
600#endif /* CONFIG_MAGIC_SYSRQ */
601 tty_insert_flip_char(tty, buf[i], 0);
602 }
603
604 if (tty->flip.count)
605 tty_schedule_flip(tty);
606
607 /*
608 * Account for the total amount read in one loop, and if above
Milton Miller8b67f8c2005-07-07 17:56:18 -0700609 * 64 bytes, we do a quick schedule loop to let the tty grok
610 * the data and eventually throttle us.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 */
612 read_total += n;
613 if (read_total >= 64) {
614 poll_mask |= HVC_POLL_QUICK;
615 break;
616 }
617 }
618 throttled:
619 /* Wakeup write queue if necessary */
620 if (hp->do_wakeup) {
621 hp->do_wakeup = 0;
622 tty_wakeup(tty);
623 }
624 bail:
625 spin_unlock_irqrestore(&hp->lock, flags);
626
627 return poll_mask;
628}
629
630#if defined(CONFIG_XMON) && defined(CONFIG_SMP)
631extern cpumask_t cpus_in_xmon;
632#else
633static const cpumask_t cpus_in_xmon = CPU_MASK_NONE;
634#endif
635
636/*
637 * This kthread is either polling or interrupt driven. This is determined by
638 * calling hvc_poll() who determines whether a console adapter support
639 * interrupts.
640 */
641int khvcd(void *unused)
642{
643 int poll_mask;
644 struct hvc_struct *hp;
645
646 __set_current_state(TASK_RUNNING);
647 do {
648 poll_mask = 0;
649 hvc_kicked = 0;
650 wmb();
651 if (cpus_empty(cpus_in_xmon)) {
652 spin_lock(&hvc_structs_lock);
653 list_for_each_entry(hp, &hvc_structs, next) {
654 /*hp = list_entry(node, struct hvc_struct, * next); */
655 poll_mask |= hvc_poll(hp);
656 }
657 spin_unlock(&hvc_structs_lock);
658 } else
659 poll_mask |= HVC_POLL_READ;
660 if (hvc_kicked)
661 continue;
662 if (poll_mask & HVC_POLL_QUICK) {
663 yield();
664 continue;
665 }
666 set_current_state(TASK_INTERRUPTIBLE);
667 if (!hvc_kicked) {
668 if (poll_mask == 0)
669 schedule();
670 else
671 msleep_interruptible(TIMEOUT);
672 }
673 __set_current_state(TASK_RUNNING);
674 } while (!kthread_should_stop());
675
676 return 0;
677}
678
679static struct tty_operations hvc_ops = {
680 .open = hvc_open,
681 .close = hvc_close,
682 .write = hvc_write,
683 .hangup = hvc_hangup,
684 .unthrottle = hvc_unthrottle,
685 .write_room = hvc_write_room,
686 .chars_in_buffer = hvc_chars_in_buffer,
687};
688
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689/* callback when the kboject ref count reaches zero. */
690static void destroy_hvc_struct(struct kobject *kobj)
691{
692 struct hvc_struct *hp = container_of(kobj, struct hvc_struct, kobj);
693 unsigned long flags;
694
695 spin_lock(&hvc_structs_lock);
696
697 spin_lock_irqsave(&hp->lock, flags);
698 list_del(&(hp->next));
699 spin_unlock_irqrestore(&hp->lock, flags);
700
701 spin_unlock(&hvc_structs_lock);
702
703 kfree(hp);
704}
705
706static struct kobj_type hvc_kobj_type = {
707 .release = destroy_hvc_struct,
708};
709
710static int __devinit hvc_probe(
711 struct vio_dev *dev,
712 const struct vio_device_id *id)
713{
714 struct hvc_struct *hp;
Milton Miller6f248082005-07-07 17:56:17 -0700715 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716
717 /* probed with invalid parameters. */
718 if (!dev || !id)
719 return -EPERM;
720
721 hp = kmalloc(sizeof(*hp), GFP_KERNEL);
722 if (!hp)
723 return -ENOMEM;
724
725 memset(hp, 0x00, sizeof(*hp));
726 hp->vtermno = dev->unit_address;
727 hp->vdev = dev;
728 hp->vdev->dev.driver_data = hp;
729 hp->irq = dev->irq;
730
731 kobject_init(&hp->kobj);
732 hp->kobj.ktype = &hvc_kobj_type;
733
734 spin_lock_init(&hp->lock);
735 spin_lock(&hvc_structs_lock);
Milton Miller6f248082005-07-07 17:56:17 -0700736
737 /*
738 * find index to use:
739 * see if this vterm id matches one registered for console.
740 */
741 for (i=0; i < MAX_NR_HVC_CONSOLES; i++)
742 if (vtermnos[i] == hp->vtermno)
743 break;
744
745 /* no matching slot, just use a counter */
746 if (i >= MAX_NR_HVC_CONSOLES)
747 i = ++last_hvc;
748
749 hp->index = i;
750
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 list_add_tail(&(hp->next), &hvc_structs);
752 spin_unlock(&hvc_structs_lock);
753
754 return 0;
755}
756
757static int __devexit hvc_remove(struct vio_dev *dev)
758{
759 struct hvc_struct *hp = dev->dev.driver_data;
760 unsigned long flags;
761 struct kobject *kobjp;
762 struct tty_struct *tty;
763
764 spin_lock_irqsave(&hp->lock, flags);
765 tty = hp->tty;
766 kobjp = &hp->kobj;
767
768 if (hp->index < MAX_NR_HVC_CONSOLES)
769 vtermnos[hp->index] = -1;
770
771 /* Don't whack hp->irq because tty_hangup() will need to free the irq. */
772
773 spin_unlock_irqrestore(&hp->lock, flags);
774
775 /*
776 * We 'put' the instance that was grabbed when the kobject instance
777 * was intialized using kobject_init(). Let the last holder of this
778 * kobject cause it to be removed, which will probably be the tty_hangup
779 * below.
780 */
781 kobject_put(kobjp);
782
783 /*
784 * This function call will auto chain call hvc_hangup. The tty should
785 * always be valid at this time unless a simultaneous tty close already
786 * cleaned up the hvc_struct.
787 */
788 if (tty)
789 tty_hangup(tty);
790 return 0;
791}
792
Milton Miller837dcfa2005-07-07 17:56:16 -0700793char hvc_driver_name[] = "hvc_console";
794
795static struct vio_device_id hvc_driver_table[] __devinitdata= {
796 {"serial", "hvterm1"},
797 { NULL, }
798};
799MODULE_DEVICE_TABLE(vio, hvc_driver_table);
800
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801static struct vio_driver hvc_vio_driver = {
802 .name = hvc_driver_name,
803 .id_table = hvc_driver_table,
804 .probe = hvc_probe,
805 .remove = hvc_remove,
806};
807
808/* Driver initialization. Follow console initialization. This is where the TTY
809 * interfaces start to become available. */
810int __init hvc_init(void)
811{
812 int rc;
813
814 /* We need more than num_vterms adapters due to hotplug additions. */
815 hvc_driver = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS);
816 /* hvc_driver = alloc_tty_driver(num_vterms); */
817 if (!hvc_driver)
818 return -ENOMEM;
819
820 hvc_driver->owner = THIS_MODULE;
821 hvc_driver->devfs_name = "hvc/";
822 hvc_driver->driver_name = "hvc";
823 hvc_driver->name = "hvc";
824 hvc_driver->major = HVC_MAJOR;
825 hvc_driver->minor_start = HVC_MINOR;
826 hvc_driver->type = TTY_DRIVER_TYPE_SYSTEM;
827 hvc_driver->init_termios = tty_std_termios;
828 hvc_driver->flags = TTY_DRIVER_REAL_RAW;
829 tty_set_operations(hvc_driver, &hvc_ops);
830
831 if (tty_register_driver(hvc_driver))
832 panic("Couldn't register hvc console driver\n");
833
834 /* Always start the kthread because there can be hotplug vty adapters
835 * added later. */
836 hvc_task = kthread_run(khvcd, NULL, "khvcd");
837 if (IS_ERR(hvc_task)) {
838 panic("Couldn't create kthread for console.\n");
839 put_tty_driver(hvc_driver);
840 return -EIO;
841 }
842
843 /* Register as a vio device to receive callbacks */
844 rc = vio_register_driver(&hvc_vio_driver);
845
846 return rc;
847}
Milton Miller837dcfa2005-07-07 17:56:16 -0700848module_init(hvc_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849
Milton Miller320da0d2005-07-07 17:56:20 -0700850/* This isn't particularily necessary due to this being a console driver
851 * but it is nice to be thorough.
852 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853static void __exit hvc_exit(void)
854{
855 kthread_stop(hvc_task);
856
857 vio_unregister_driver(&hvc_vio_driver);
858 tty_unregister_driver(hvc_driver);
859 /* return tty_struct instances allocated in hvc_init(). */
860 put_tty_driver(hvc_driver);
Milton Miller320da0d2005-07-07 17:56:20 -0700861 unregister_console(&hvc_con_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863module_exit(hvc_exit);