blob: a9522189fc9efeaa82dab6d3b479df11d89a8412 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C) 2004 Hollis Blanchard <hollisb@us.ibm.com>, IBM
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18
19/* Host Virtual Serial Interface (HVSI) is a protocol between the hosted OS
20 * and the service processor on IBM pSeries servers. On these servers, there
21 * are no serial ports under the OS's control, and sometimes there is no other
22 * console available either. However, the service processor has two standard
23 * serial ports, so this over-complicated protocol allows the OS to control
24 * those ports by proxy.
25 *
26 * Besides data, the procotol supports the reading/writing of the serial
27 * port's DTR line, and the reading of the CD line. This is to allow the OS to
28 * control a modem attached to the service processor's serial port. Note that
29 * the OS cannot change the speed of the port through this protocol.
30 */
31
32#undef DEBUG
33
34#include <linux/console.h>
35#include <linux/ctype.h>
36#include <linux/delay.h>
37#include <linux/init.h>
38#include <linux/interrupt.h>
39#include <linux/module.h>
40#include <linux/major.h>
41#include <linux/kernel.h>
42#include <linux/sched.h>
43#include <linux/spinlock.h>
44#include <linux/sysrq.h>
45#include <linux/tty.h>
46#include <linux/tty_flip.h>
47#include <asm/hvcall.h>
48#include <asm/hvconsole.h>
49#include <asm/prom.h>
50#include <asm/uaccess.h>
51#include <asm/vio.h>
52#include <asm/param.h>
53
54#define HVSI_MAJOR 229
55#define HVSI_MINOR 128
56#define MAX_NR_HVSI_CONSOLES 4
57
58#define HVSI_TIMEOUT (5*HZ)
59#define HVSI_VERSION 1
60#define HVSI_MAX_PACKET 256
61#define HVSI_MAX_READ 16
62#define HVSI_MAX_OUTGOING_DATA 12
63#define N_OUTBUF 12
64
65/*
66 * we pass data via two 8-byte registers, so we would like our char arrays
67 * properly aligned for those loads.
68 */
69#define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
70
71struct hvsi_struct {
72 struct work_struct writer;
73 struct work_struct handshaker;
74 wait_queue_head_t emptyq; /* woken when outbuf is emptied */
75 wait_queue_head_t stateq; /* woken when HVSI state changes */
76 spinlock_t lock;
77 int index;
78 struct tty_struct *tty;
79 unsigned int count;
80 uint8_t throttle_buf[128];
81 uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */
82 /* inbuf is for packet reassembly. leave a little room for leftovers. */
83 uint8_t inbuf[HVSI_MAX_PACKET + HVSI_MAX_READ];
84 uint8_t *inbuf_end;
85 int n_throttle;
86 int n_outbuf;
87 uint32_t vtermno;
88 uint32_t virq;
89 atomic_t seqno; /* HVSI packet sequence number */
90 uint16_t mctrl;
91 uint8_t state; /* HVSI protocol state */
92 uint8_t flags;
93#ifdef CONFIG_MAGIC_SYSRQ
94 uint8_t sysrq;
95#endif /* CONFIG_MAGIC_SYSRQ */
96};
97static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES];
98
99static struct tty_driver *hvsi_driver;
100static int hvsi_count;
101static int (*hvsi_wait)(struct hvsi_struct *hp, int state);
102
103enum HVSI_PROTOCOL_STATE {
104 HVSI_CLOSED,
105 HVSI_WAIT_FOR_VER_RESPONSE,
106 HVSI_WAIT_FOR_VER_QUERY,
107 HVSI_OPEN,
108 HVSI_WAIT_FOR_MCTRL_RESPONSE,
109 HVSI_FSP_DIED,
110};
111#define HVSI_CONSOLE 0x1
112
113#define VS_DATA_PACKET_HEADER 0xff
114#define VS_CONTROL_PACKET_HEADER 0xfe
115#define VS_QUERY_PACKET_HEADER 0xfd
116#define VS_QUERY_RESPONSE_PACKET_HEADER 0xfc
117
118/* control verbs */
119#define VSV_SET_MODEM_CTL 1 /* to service processor only */
120#define VSV_MODEM_CTL_UPDATE 2 /* from service processor only */
121#define VSV_CLOSE_PROTOCOL 3
122
123/* query verbs */
124#define VSV_SEND_VERSION_NUMBER 1
125#define VSV_SEND_MODEM_CTL_STATUS 2
126
127/* yes, these masks are not consecutive. */
128#define HVSI_TSDTR 0x01
129#define HVSI_TSCD 0x20
130
131struct hvsi_header {
132 uint8_t type;
133 uint8_t len;
134 uint16_t seqno;
135} __attribute__((packed));
136
137struct hvsi_data {
138 uint8_t type;
139 uint8_t len;
140 uint16_t seqno;
141 uint8_t data[HVSI_MAX_OUTGOING_DATA];
142} __attribute__((packed));
143
144struct hvsi_control {
145 uint8_t type;
146 uint8_t len;
147 uint16_t seqno;
148 uint16_t verb;
149 /* optional depending on verb: */
150 uint32_t word;
151 uint32_t mask;
152} __attribute__((packed));
153
154struct hvsi_query {
155 uint8_t type;
156 uint8_t len;
157 uint16_t seqno;
158 uint16_t verb;
159} __attribute__((packed));
160
161struct hvsi_query_response {
162 uint8_t type;
163 uint8_t len;
164 uint16_t seqno;
165 uint16_t verb;
166 uint16_t query_seqno;
167 union {
168 uint8_t version;
169 uint32_t mctrl_word;
170 } u;
171} __attribute__((packed));
172
173
174
175static inline int is_console(struct hvsi_struct *hp)
176{
177 return hp->flags & HVSI_CONSOLE;
178}
179
180static inline int is_open(struct hvsi_struct *hp)
181{
182 /* if we're waiting for an mctrl then we're already open */
183 return (hp->state == HVSI_OPEN)
184 || (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE);
185}
186
187static inline void print_state(struct hvsi_struct *hp)
188{
189#ifdef DEBUG
190 static const char *state_names[] = {
191 "HVSI_CLOSED",
192 "HVSI_WAIT_FOR_VER_RESPONSE",
193 "HVSI_WAIT_FOR_VER_QUERY",
194 "HVSI_OPEN",
195 "HVSI_WAIT_FOR_MCTRL_RESPONSE",
196 "HVSI_FSP_DIED",
197 };
198 const char *name = state_names[hp->state];
199
Tobias Klauserfe971072006-01-09 20:54:02 -0800200 if (hp->state > ARRAY_SIZE(state_names))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 name = "UNKNOWN";
202
203 pr_debug("hvsi%i: state = %s\n", hp->index, name);
204#endif /* DEBUG */
205}
206
207static inline void __set_state(struct hvsi_struct *hp, int state)
208{
209 hp->state = state;
210 print_state(hp);
211 wake_up_all(&hp->stateq);
212}
213
214static inline void set_state(struct hvsi_struct *hp, int state)
215{
216 unsigned long flags;
217
218 spin_lock_irqsave(&hp->lock, flags);
219 __set_state(hp, state);
220 spin_unlock_irqrestore(&hp->lock, flags);
221}
222
223static inline int len_packet(const uint8_t *packet)
224{
225 return (int)((struct hvsi_header *)packet)->len;
226}
227
228static inline int is_header(const uint8_t *packet)
229{
230 struct hvsi_header *header = (struct hvsi_header *)packet;
231 return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER;
232}
233
234static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet)
235{
236 if (hp->inbuf_end < packet + sizeof(struct hvsi_header))
237 return 0; /* don't even have the packet header */
238
239 if (hp->inbuf_end < (packet + len_packet(packet)))
240 return 0; /* don't have the rest of the packet */
241
242 return 1;
243}
244
245/* shift remaining bytes in packetbuf down */
246static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to)
247{
248 int remaining = (int)(hp->inbuf_end - read_to);
249
250 pr_debug("%s: %i chars remain\n", __FUNCTION__, remaining);
251
252 if (read_to != hp->inbuf)
253 memmove(hp->inbuf, read_to, remaining);
254
255 hp->inbuf_end = hp->inbuf + remaining;
256}
257
258#ifdef DEBUG
259#define dbg_dump_packet(packet) dump_packet(packet)
260#define dbg_dump_hex(data, len) dump_hex(data, len)
261#else
262#define dbg_dump_packet(packet) do { } while (0)
263#define dbg_dump_hex(data, len) do { } while (0)
264#endif
265
266static void dump_hex(const uint8_t *data, int len)
267{
268 int i;
269
270 printk(" ");
271 for (i=0; i < len; i++)
272 printk("%.2x", data[i]);
273
274 printk("\n ");
275 for (i=0; i < len; i++) {
276 if (isprint(data[i]))
277 printk("%c", data[i]);
278 else
279 printk(".");
280 }
281 printk("\n");
282}
283
284static void dump_packet(uint8_t *packet)
285{
286 struct hvsi_header *header = (struct hvsi_header *)packet;
287
288 printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len,
289 header->seqno);
290
291 dump_hex(packet, header->len);
292}
293
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
295{
296 unsigned long got;
297
Milton Miller88de0be2005-07-07 17:56:27 -0700298 got = hvc_get_chars(hp->vtermno, buf, count);
299
300 return got;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301}
302
303static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
304 struct tty_struct **to_hangup, struct hvsi_struct **to_handshake)
305{
306 struct hvsi_control *header = (struct hvsi_control *)packet;
307
308 switch (header->verb) {
309 case VSV_MODEM_CTL_UPDATE:
310 if ((header->word & HVSI_TSCD) == 0) {
311 /* CD went away; no more connection */
312 pr_debug("hvsi%i: CD dropped\n", hp->index);
313 hp->mctrl &= TIOCM_CD;
314 if (!(hp->tty->flags & CLOCAL))
315 *to_hangup = hp->tty;
316 }
317 break;
318 case VSV_CLOSE_PROTOCOL:
319 pr_debug("hvsi%i: service processor came back\n", hp->index);
320 if (hp->state != HVSI_CLOSED) {
321 *to_handshake = hp;
322 }
323 break;
324 default:
325 printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ",
326 hp->index);
327 dump_packet(packet);
328 break;
329 }
330}
331
332static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
333{
334 struct hvsi_query_response *resp = (struct hvsi_query_response *)packet;
335
336 switch (hp->state) {
337 case HVSI_WAIT_FOR_VER_RESPONSE:
338 __set_state(hp, HVSI_WAIT_FOR_VER_QUERY);
339 break;
340 case HVSI_WAIT_FOR_MCTRL_RESPONSE:
341 hp->mctrl = 0;
342 if (resp->u.mctrl_word & HVSI_TSDTR)
343 hp->mctrl |= TIOCM_DTR;
344 if (resp->u.mctrl_word & HVSI_TSCD)
345 hp->mctrl |= TIOCM_CD;
346 __set_state(hp, HVSI_OPEN);
347 break;
348 default:
349 printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index);
350 dump_packet(packet);
351 break;
352 }
353}
354
355/* respond to service processor's version query */
356static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno)
357{
358 struct hvsi_query_response packet __ALIGNED__;
359 int wrote;
360
361 packet.type = VS_QUERY_RESPONSE_PACKET_HEADER;
362 packet.len = sizeof(struct hvsi_query_response);
363 packet.seqno = atomic_inc_return(&hp->seqno);
364 packet.verb = VSV_SEND_VERSION_NUMBER;
365 packet.u.version = HVSI_VERSION;
366 packet.query_seqno = query_seqno+1;
367
368 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
369 dbg_dump_hex((uint8_t*)&packet, packet.len);
370
371 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
372 if (wrote != packet.len) {
373 printk(KERN_ERR "hvsi%i: couldn't send query response!\n",
374 hp->index);
375 return -EIO;
376 }
377
378 return 0;
379}
380
381static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
382{
383 struct hvsi_query *query = (struct hvsi_query *)packet;
384
385 switch (hp->state) {
386 case HVSI_WAIT_FOR_VER_QUERY:
387 hvsi_version_respond(hp, query->seqno);
388 __set_state(hp, HVSI_OPEN);
389 break;
390 default:
391 printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index);
392 dump_packet(packet);
393 break;
394 }
395}
396
397static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
398{
399 int i;
400
401 for (i=0; i < len; i++) {
402 char c = buf[i];
403#ifdef CONFIG_MAGIC_SYSRQ
404 if (c == '\0') {
405 hp->sysrq = 1;
406 continue;
407 } else if (hp->sysrq) {
408 handle_sysrq(c, NULL, hp->tty);
409 hp->sysrq = 0;
410 continue;
411 }
412#endif /* CONFIG_MAGIC_SYSRQ */
413 tty_insert_flip_char(hp->tty, c, 0);
414 }
415}
416
417/*
418 * We could get 252 bytes of data at once here. But the tty layer only
419 * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow
420 * it. Accordingly we won't send more than 128 bytes at a time to the flip
421 * buffer, which will give the tty buffer a chance to throttle us. Should the
422 * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be
423 * revisited.
424 */
425#define TTY_THRESHOLD_THROTTLE 128
426static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp,
427 const uint8_t *packet)
428{
429 const struct hvsi_header *header = (const struct hvsi_header *)packet;
430 const uint8_t *data = packet + sizeof(struct hvsi_header);
431 int datalen = header->len - sizeof(struct hvsi_header);
432 int overflow = datalen - TTY_THRESHOLD_THROTTLE;
433
434 pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data);
435
436 if (datalen == 0)
437 return NULL;
438
439 if (overflow > 0) {
440 pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __FUNCTION__);
441 datalen = TTY_THRESHOLD_THROTTLE;
442 }
443
444 hvsi_insert_chars(hp, data, datalen);
445
446 if (overflow > 0) {
447 /*
448 * we still have more data to deliver, so we need to save off the
449 * overflow and send it later
450 */
451 pr_debug("%s: deferring overflow\n", __FUNCTION__);
452 memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow);
453 hp->n_throttle = overflow;
454 }
455
456 return hp->tty;
457}
458
459/*
460 * Returns true/false indicating data successfully read from hypervisor.
461 * Used both to get packets for tty connections and to advance the state
462 * machine during console handshaking (in which case tty = NULL and we ignore
463 * incoming data).
464 */
465static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip,
466 struct tty_struct **hangup, struct hvsi_struct **handshake)
467{
468 uint8_t *packet = hp->inbuf;
469 int chunklen;
470
471 *flip = NULL;
472 *hangup = NULL;
473 *handshake = NULL;
474
475 chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ);
476 if (chunklen == 0) {
477 pr_debug("%s: 0-length read\n", __FUNCTION__);
478 return 0;
479 }
480
481 pr_debug("%s: got %i bytes\n", __FUNCTION__, chunklen);
482 dbg_dump_hex(hp->inbuf_end, chunklen);
483
484 hp->inbuf_end += chunklen;
485
486 /* handle all completed packets */
487 while ((packet < hp->inbuf_end) && got_packet(hp, packet)) {
488 struct hvsi_header *header = (struct hvsi_header *)packet;
489
490 if (!is_header(packet)) {
491 printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index);
492 /* skip bytes until we find a header or run out of data */
493 while ((packet < hp->inbuf_end) && (!is_header(packet)))
494 packet++;
495 continue;
496 }
497
498 pr_debug("%s: handling %i-byte packet\n", __FUNCTION__,
499 len_packet(packet));
500 dbg_dump_packet(packet);
501
502 switch (header->type) {
503 case VS_DATA_PACKET_HEADER:
504 if (!is_open(hp))
505 break;
506 if (hp->tty == NULL)
507 break; /* no tty buffer to put data in */
508 *flip = hvsi_recv_data(hp, packet);
509 break;
510 case VS_CONTROL_PACKET_HEADER:
511 hvsi_recv_control(hp, packet, hangup, handshake);
512 break;
513 case VS_QUERY_RESPONSE_PACKET_HEADER:
514 hvsi_recv_response(hp, packet);
515 break;
516 case VS_QUERY_PACKET_HEADER:
517 hvsi_recv_query(hp, packet);
518 break;
519 default:
520 printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n",
521 hp->index, header->type);
522 dump_packet(packet);
523 break;
524 }
525
526 packet += len_packet(packet);
527
528 if (*hangup || *handshake) {
529 pr_debug("%s: hangup or handshake\n", __FUNCTION__);
530 /*
531 * we need to send the hangup now before receiving any more data.
532 * If we get "data, hangup, data", we can't deliver the second
533 * data before the hangup.
534 */
535 break;
536 }
537 }
538
539 compact_inbuf(hp, packet);
540
541 return 1;
542}
543
544static void hvsi_send_overflow(struct hvsi_struct *hp)
545{
546 pr_debug("%s: delivering %i bytes overflow\n", __FUNCTION__,
547 hp->n_throttle);
548
549 hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle);
550 hp->n_throttle = 0;
551}
552
553/*
554 * must get all pending data because we only get an irq on empty->non-empty
555 * transition
556 */
557static irqreturn_t hvsi_interrupt(int irq, void *arg, struct pt_regs *regs)
558{
559 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
560 struct tty_struct *flip;
561 struct tty_struct *hangup;
562 struct hvsi_struct *handshake;
563 unsigned long flags;
564 int again = 1;
565
566 pr_debug("%s\n", __FUNCTION__);
567
568 while (again) {
569 spin_lock_irqsave(&hp->lock, flags);
570 again = hvsi_load_chunk(hp, &flip, &hangup, &handshake);
571 spin_unlock_irqrestore(&hp->lock, flags);
572
573 /*
574 * we have to call tty_flip_buffer_push() and tty_hangup() outside our
575 * spinlock. But we also have to keep going until we've read all the
576 * available data.
577 */
578
579 if (flip) {
580 /* there was data put in the tty flip buffer */
581 tty_flip_buffer_push(flip);
582 flip = NULL;
583 }
584
585 if (hangup) {
586 tty_hangup(hangup);
587 }
588
589 if (handshake) {
590 pr_debug("hvsi%i: attempting re-handshake\n", handshake->index);
591 schedule_work(&handshake->handshaker);
592 }
593 }
594
595 spin_lock_irqsave(&hp->lock, flags);
596 if (hp->tty && hp->n_throttle
597 && (!test_bit(TTY_THROTTLED, &hp->tty->flags))) {
598 /* we weren't hung up and we weren't throttled, so we can deliver the
599 * rest now */
600 flip = hp->tty;
601 hvsi_send_overflow(hp);
602 }
603 spin_unlock_irqrestore(&hp->lock, flags);
604
605 if (flip) {
606 tty_flip_buffer_push(flip);
607 }
608
609 return IRQ_HANDLED;
610}
611
612/* for boot console, before the irq handler is running */
613static int __init poll_for_state(struct hvsi_struct *hp, int state)
614{
615 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
616
617 for (;;) {
618 hvsi_interrupt(hp->virq, (void *)hp, NULL); /* get pending data */
619
620 if (hp->state == state)
621 return 0;
622
623 mdelay(5);
624 if (time_after(jiffies, end_jiffies))
625 return -EIO;
626 }
627}
628
629/* wait for irq handler to change our state */
630static int wait_for_state(struct hvsi_struct *hp, int state)
631{
632 int ret = 0;
633
634 if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT))
635 ret = -EIO;
636
637 return ret;
638}
639
640static int hvsi_query(struct hvsi_struct *hp, uint16_t verb)
641{
642 struct hvsi_query packet __ALIGNED__;
643 int wrote;
644
645 packet.type = VS_QUERY_PACKET_HEADER;
646 packet.len = sizeof(struct hvsi_query);
647 packet.seqno = atomic_inc_return(&hp->seqno);
648 packet.verb = verb;
649
650 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
651 dbg_dump_hex((uint8_t*)&packet, packet.len);
652
653 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
654 if (wrote != packet.len) {
655 printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index,
656 wrote);
657 return -EIO;
658 }
659
660 return 0;
661}
662
663static int hvsi_get_mctrl(struct hvsi_struct *hp)
664{
665 int ret;
666
667 set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE);
668 hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS);
669
670 ret = hvsi_wait(hp, HVSI_OPEN);
671 if (ret < 0) {
672 printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index);
673 set_state(hp, HVSI_OPEN);
674 return ret;
675 }
676
677 pr_debug("%s: mctrl 0x%x\n", __FUNCTION__, hp->mctrl);
678
679 return 0;
680}
681
682/* note that we can only set DTR */
683static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl)
684{
685 struct hvsi_control packet __ALIGNED__;
686 int wrote;
687
688 packet.type = VS_CONTROL_PACKET_HEADER,
689 packet.seqno = atomic_inc_return(&hp->seqno);
690 packet.len = sizeof(struct hvsi_control);
691 packet.verb = VSV_SET_MODEM_CTL;
692 packet.mask = HVSI_TSDTR;
693
694 if (mctrl & TIOCM_DTR)
695 packet.word = HVSI_TSDTR;
696
697 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
698 dbg_dump_hex((uint8_t*)&packet, packet.len);
699
700 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
701 if (wrote != packet.len) {
702 printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index);
703 return -EIO;
704 }
705
706 return 0;
707}
708
709static void hvsi_drain_input(struct hvsi_struct *hp)
710{
711 uint8_t buf[HVSI_MAX_READ] __ALIGNED__;
712 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
713
714 while (time_before(end_jiffies, jiffies))
715 if (0 == hvsi_read(hp, buf, HVSI_MAX_READ))
716 break;
717}
718
719static int hvsi_handshake(struct hvsi_struct *hp)
720{
721 int ret;
722
723 /*
724 * We could have a CLOSE or other data waiting for us before we even try
725 * to open; try to throw it all away so we don't get confused. (CLOSE
726 * is the first message sent up the pipe when the FSP comes online. We
727 * need to distinguish between "it came up a while ago and we're the first
728 * user" and "it was just reset before it saw our handshake packet".)
729 */
730 hvsi_drain_input(hp);
731
732 set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE);
733 ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER);
734 if (ret < 0) {
735 printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index);
736 return ret;
737 }
738
739 ret = hvsi_wait(hp, HVSI_OPEN);
740 if (ret < 0)
741 return ret;
742
743 return 0;
744}
745
746static void hvsi_handshaker(void *arg)
747{
748 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
749
750 if (hvsi_handshake(hp) >= 0)
751 return;
752
753 printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index);
754 if (is_console(hp)) {
755 /*
756 * ttys will re-attempt the handshake via hvsi_open, but
757 * the console will not.
758 */
759 printk(KERN_ERR "hvsi%i: lost console!\n", hp->index);
760 }
761}
762
763static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count)
764{
765 struct hvsi_data packet __ALIGNED__;
766 int ret;
767
768 BUG_ON(count > HVSI_MAX_OUTGOING_DATA);
769
770 packet.type = VS_DATA_PACKET_HEADER;
771 packet.seqno = atomic_inc_return(&hp->seqno);
772 packet.len = count + sizeof(struct hvsi_header);
773 memcpy(&packet.data, buf, count);
774
775 ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
776 if (ret == packet.len) {
777 /* return the number of chars written, not the packet length */
778 return count;
779 }
780 return ret; /* return any errors */
781}
782
783static void hvsi_close_protocol(struct hvsi_struct *hp)
784{
785 struct hvsi_control packet __ALIGNED__;
786
787 packet.type = VS_CONTROL_PACKET_HEADER;
788 packet.seqno = atomic_inc_return(&hp->seqno);
789 packet.len = 6;
790 packet.verb = VSV_CLOSE_PROTOCOL;
791
792 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
793 dbg_dump_hex((uint8_t*)&packet, packet.len);
794
795 hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
796}
797
798static int hvsi_open(struct tty_struct *tty, struct file *filp)
799{
800 struct hvsi_struct *hp;
801 unsigned long flags;
802 int line = tty->index;
803 int ret;
804
805 pr_debug("%s\n", __FUNCTION__);
806
807 if (line < 0 || line >= hvsi_count)
808 return -ENODEV;
809 hp = &hvsi_ports[line];
810
811 tty->driver_data = hp;
812 tty->low_latency = 1; /* avoid throttle/tty_flip_buffer_push race */
813
814 mb();
815 if (hp->state == HVSI_FSP_DIED)
816 return -EIO;
817
818 spin_lock_irqsave(&hp->lock, flags);
819 hp->tty = tty;
820 hp->count++;
821 atomic_set(&hp->seqno, 0);
822 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
823 spin_unlock_irqrestore(&hp->lock, flags);
824
825 if (is_console(hp))
826 return 0; /* this has already been handshaked as the console */
827
828 ret = hvsi_handshake(hp);
829 if (ret < 0) {
830 printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name);
831 return ret;
832 }
833
834 ret = hvsi_get_mctrl(hp);
835 if (ret < 0) {
836 printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name);
837 return ret;
838 }
839
840 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
841 if (ret < 0) {
842 printk(KERN_ERR "%s: couldn't set DTR\n", tty->name);
843 return ret;
844 }
845
846 return 0;
847}
848
849/* wait for hvsi_write_worker to empty hp->outbuf */
850static void hvsi_flush_output(struct hvsi_struct *hp)
851{
852 wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT);
853
854 /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */
855 cancel_delayed_work(&hp->writer);
856 flush_scheduled_work();
857
858 /*
859 * it's also possible that our timeout expired and hvsi_write_worker
860 * didn't manage to push outbuf. poof.
861 */
862 hp->n_outbuf = 0;
863}
864
865static void hvsi_close(struct tty_struct *tty, struct file *filp)
866{
867 struct hvsi_struct *hp = tty->driver_data;
868 unsigned long flags;
869
870 pr_debug("%s\n", __FUNCTION__);
871
872 if (tty_hung_up_p(filp))
873 return;
874
875 spin_lock_irqsave(&hp->lock, flags);
876
877 if (--hp->count == 0) {
878 hp->tty = NULL;
879 hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */
880
881 /* only close down connection if it is not the console */
882 if (!is_console(hp)) {
883 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */
884 __set_state(hp, HVSI_CLOSED);
885 /*
886 * any data delivered to the tty layer after this will be
887 * discarded (except for XON/XOFF)
888 */
889 tty->closing = 1;
890
891 spin_unlock_irqrestore(&hp->lock, flags);
892
893 /* let any existing irq handlers finish. no more will start. */
894 synchronize_irq(hp->virq);
895
896 /* hvsi_write_worker will re-schedule until outbuf is empty. */
897 hvsi_flush_output(hp);
898
899 /* tell FSP to stop sending data */
900 hvsi_close_protocol(hp);
901
902 /*
903 * drain anything FSP is still in the middle of sending, and let
904 * hvsi_handshake drain the rest on the next open.
905 */
906 hvsi_drain_input(hp);
907
908 spin_lock_irqsave(&hp->lock, flags);
909 }
910 } else if (hp->count < 0)
911 printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n",
912 hp - hvsi_ports, hp->count);
913
914 spin_unlock_irqrestore(&hp->lock, flags);
915}
916
917static void hvsi_hangup(struct tty_struct *tty)
918{
919 struct hvsi_struct *hp = tty->driver_data;
920 unsigned long flags;
921
922 pr_debug("%s\n", __FUNCTION__);
923
924 spin_lock_irqsave(&hp->lock, flags);
925
926 hp->count = 0;
927 hp->n_outbuf = 0;
928 hp->tty = NULL;
929
930 spin_unlock_irqrestore(&hp->lock, flags);
931}
932
933/* called with hp->lock held */
934static void hvsi_push(struct hvsi_struct *hp)
935{
936 int n;
937
938 if (hp->n_outbuf <= 0)
939 return;
940
941 n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf);
942 if (n > 0) {
943 /* success */
944 pr_debug("%s: wrote %i chars\n", __FUNCTION__, n);
945 hp->n_outbuf = 0;
946 } else if (n == -EIO) {
947 __set_state(hp, HVSI_FSP_DIED);
948 printk(KERN_ERR "hvsi%i: service processor died\n", hp->index);
949 }
950}
951
952/* hvsi_write_worker will keep rescheduling itself until outbuf is empty */
953static void hvsi_write_worker(void *arg)
954{
955 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
956 unsigned long flags;
957#ifdef DEBUG
958 static long start_j = 0;
959
960 if (start_j == 0)
961 start_j = jiffies;
962#endif /* DEBUG */
963
964 spin_lock_irqsave(&hp->lock, flags);
965
966 pr_debug("%s: %i chars in buffer\n", __FUNCTION__, hp->n_outbuf);
967
968 if (!is_open(hp)) {
969 /*
970 * We could have a non-open connection if the service processor died
971 * while we were busily scheduling ourselves. In that case, it could
972 * be minutes before the service processor comes back, so only try
973 * again once a second.
974 */
975 schedule_delayed_work(&hp->writer, HZ);
976 goto out;
977 }
978
979 hvsi_push(hp);
980 if (hp->n_outbuf > 0)
981 schedule_delayed_work(&hp->writer, 10);
982 else {
983#ifdef DEBUG
984 pr_debug("%s: outbuf emptied after %li jiffies\n", __FUNCTION__,
985 jiffies - start_j);
986 start_j = 0;
987#endif /* DEBUG */
988 wake_up_all(&hp->emptyq);
989 if (test_bit(TTY_DO_WRITE_WAKEUP, &hp->tty->flags)
990 && hp->tty->ldisc.write_wakeup)
991 hp->tty->ldisc.write_wakeup(hp->tty);
992 wake_up_interruptible(&hp->tty->write_wait);
993 }
994
995out:
996 spin_unlock_irqrestore(&hp->lock, flags);
997}
998
999static int hvsi_write_room(struct tty_struct *tty)
1000{
1001 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1002
1003 return N_OUTBUF - hp->n_outbuf;
1004}
1005
1006static int hvsi_chars_in_buffer(struct tty_struct *tty)
1007{
1008 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1009
1010 return hp->n_outbuf;
1011}
1012
1013static int hvsi_write(struct tty_struct *tty,
1014 const unsigned char *buf, int count)
1015{
1016 struct hvsi_struct *hp = tty->driver_data;
1017 const char *source = buf;
1018 unsigned long flags;
1019 int total = 0;
1020 int origcount = count;
1021
1022 spin_lock_irqsave(&hp->lock, flags);
1023
1024 pr_debug("%s: %i chars in buffer\n", __FUNCTION__, hp->n_outbuf);
1025
1026 if (!is_open(hp)) {
1027 /* we're either closing or not yet open; don't accept data */
1028 pr_debug("%s: not open\n", __FUNCTION__);
1029 goto out;
1030 }
1031
1032 /*
1033 * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf
1034 * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
1035 * will see there is no room in outbuf and return.
1036 */
1037 while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) {
1038 int chunksize = min(count, hvsi_write_room(hp->tty));
1039
1040 BUG_ON(hp->n_outbuf < 0);
1041 memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
1042 hp->n_outbuf += chunksize;
1043
1044 total += chunksize;
1045 source += chunksize;
1046 count -= chunksize;
1047 hvsi_push(hp);
1048 }
1049
1050 if (hp->n_outbuf > 0) {
1051 /*
1052 * we weren't able to write it all to the hypervisor.
1053 * schedule another push attempt.
1054 */
1055 schedule_delayed_work(&hp->writer, 10);
1056 }
1057
1058out:
1059 spin_unlock_irqrestore(&hp->lock, flags);
1060
1061 if (total != origcount)
1062 pr_debug("%s: wanted %i, only wrote %i\n", __FUNCTION__, origcount,
1063 total);
1064
1065 return total;
1066}
1067
1068/*
1069 * I have never seen throttle or unthrottle called, so this little throttle
1070 * buffering scheme may or may not work.
1071 */
1072static void hvsi_throttle(struct tty_struct *tty)
1073{
1074 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1075
1076 pr_debug("%s\n", __FUNCTION__);
1077
1078 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE);
1079}
1080
1081static void hvsi_unthrottle(struct tty_struct *tty)
1082{
1083 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1084 unsigned long flags;
1085 int shouldflip = 0;
1086
1087 pr_debug("%s\n", __FUNCTION__);
1088
1089 spin_lock_irqsave(&hp->lock, flags);
1090 if (hp->n_throttle) {
1091 hvsi_send_overflow(hp);
1092 shouldflip = 1;
1093 }
1094 spin_unlock_irqrestore(&hp->lock, flags);
1095
1096 if (shouldflip)
1097 tty_flip_buffer_push(hp->tty);
1098
1099 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
1100}
1101
1102static int hvsi_tiocmget(struct tty_struct *tty, struct file *file)
1103{
1104 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1105
1106 hvsi_get_mctrl(hp);
1107 return hp->mctrl;
1108}
1109
1110static int hvsi_tiocmset(struct tty_struct *tty, struct file *file,
1111 unsigned int set, unsigned int clear)
1112{
1113 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1114 unsigned long flags;
1115 uint16_t new_mctrl;
1116
1117 /* we can only alter DTR */
1118 clear &= TIOCM_DTR;
1119 set &= TIOCM_DTR;
1120
1121 spin_lock_irqsave(&hp->lock, flags);
1122
1123 new_mctrl = (hp->mctrl & ~clear) | set;
1124
1125 if (hp->mctrl != new_mctrl) {
1126 hvsi_set_mctrl(hp, new_mctrl);
1127 hp->mctrl = new_mctrl;
1128 }
1129 spin_unlock_irqrestore(&hp->lock, flags);
1130
1131 return 0;
1132}
1133
1134
1135static struct tty_operations hvsi_ops = {
1136 .open = hvsi_open,
1137 .close = hvsi_close,
1138 .write = hvsi_write,
1139 .hangup = hvsi_hangup,
1140 .write_room = hvsi_write_room,
1141 .chars_in_buffer = hvsi_chars_in_buffer,
1142 .throttle = hvsi_throttle,
1143 .unthrottle = hvsi_unthrottle,
1144 .tiocmget = hvsi_tiocmget,
1145 .tiocmset = hvsi_tiocmset,
1146};
1147
1148static int __init hvsi_init(void)
1149{
1150 int i;
1151
1152 hvsi_driver = alloc_tty_driver(hvsi_count);
1153 if (!hvsi_driver)
1154 return -ENOMEM;
1155
1156 hvsi_driver->owner = THIS_MODULE;
1157 hvsi_driver->devfs_name = "hvsi/";
1158 hvsi_driver->driver_name = "hvsi";
1159 hvsi_driver->name = "hvsi";
1160 hvsi_driver->major = HVSI_MAJOR;
1161 hvsi_driver->minor_start = HVSI_MINOR;
1162 hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM;
1163 hvsi_driver->init_termios = tty_std_termios;
1164 hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
1165 hvsi_driver->flags = TTY_DRIVER_REAL_RAW;
1166 tty_set_operations(hvsi_driver, &hvsi_ops);
1167
1168 for (i=0; i < hvsi_count; i++) {
1169 struct hvsi_struct *hp = &hvsi_ports[i];
1170 int ret = 1;
1171
1172 ret = request_irq(hp->virq, hvsi_interrupt, SA_INTERRUPT, "hvsi", hp);
1173 if (ret)
1174 printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n",
1175 hp->virq, ret);
1176 }
1177 hvsi_wait = wait_for_state; /* irqs active now */
1178
1179 if (tty_register_driver(hvsi_driver))
1180 panic("Couldn't register hvsi console driver\n");
1181
1182 printk(KERN_INFO "HVSI: registered %i devices\n", hvsi_count);
1183
1184 return 0;
1185}
1186device_initcall(hvsi_init);
1187
1188/***** console (not tty) code: *****/
1189
1190static void hvsi_console_print(struct console *console, const char *buf,
1191 unsigned int count)
1192{
1193 struct hvsi_struct *hp = &hvsi_ports[console->index];
1194 char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__;
1195 unsigned int i = 0, n = 0;
1196 int ret, donecr = 0;
1197
1198 mb();
1199 if (!is_open(hp))
1200 return;
1201
1202 /*
1203 * ugh, we have to translate LF -> CRLF ourselves, in place.
1204 * copied from hvc_console.c:
1205 */
1206 while (count > 0 || i > 0) {
1207 if (count > 0 && i < sizeof(c)) {
1208 if (buf[n] == '\n' && !donecr) {
1209 c[i++] = '\r';
1210 donecr = 1;
1211 } else {
1212 c[i++] = buf[n++];
1213 donecr = 0;
1214 --count;
1215 }
1216 } else {
1217 ret = hvsi_put_chars(hp, c, i);
1218 if (ret < 0)
1219 i = 0;
1220 i -= ret;
1221 }
1222 }
1223}
1224
1225static struct tty_driver *hvsi_console_device(struct console *console,
1226 int *index)
1227{
1228 *index = console->index;
1229 return hvsi_driver;
1230}
1231
1232static int __init hvsi_console_setup(struct console *console, char *options)
1233{
1234 struct hvsi_struct *hp = &hvsi_ports[console->index];
1235 int ret;
1236
1237 if (console->index < 0 || console->index >= hvsi_count)
1238 return -1;
1239
1240 /* give the FSP a chance to change the baud rate when we re-open */
1241 hvsi_close_protocol(hp);
1242
1243 ret = hvsi_handshake(hp);
1244 if (ret < 0)
1245 return ret;
1246
1247 ret = hvsi_get_mctrl(hp);
1248 if (ret < 0)
1249 return ret;
1250
1251 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
1252 if (ret < 0)
1253 return ret;
1254
1255 hp->flags |= HVSI_CONSOLE;
1256
1257 return 0;
1258}
1259
1260static struct console hvsi_con_driver = {
1261 .name = "hvsi",
1262 .write = hvsi_console_print,
1263 .device = hvsi_console_device,
1264 .setup = hvsi_console_setup,
1265 .flags = CON_PRINTBUFFER,
1266 .index = -1,
1267};
1268
1269static int __init hvsi_console_init(void)
1270{
1271 struct device_node *vty;
1272
1273 hvsi_wait = poll_for_state; /* no irqs yet; must poll */
1274
1275 /* search device tree for vty nodes */
1276 for (vty = of_find_compatible_node(NULL, "serial", "hvterm-protocol");
1277 vty != NULL;
1278 vty = of_find_compatible_node(vty, "serial", "hvterm-protocol")) {
1279 struct hvsi_struct *hp;
1280 uint32_t *vtermno;
1281 uint32_t *irq;
1282
1283 vtermno = (uint32_t *)get_property(vty, "reg", NULL);
1284 irq = (uint32_t *)get_property(vty, "interrupts", NULL);
1285 if (!vtermno || !irq)
1286 continue;
1287
1288 if (hvsi_count >= MAX_NR_HVSI_CONSOLES) {
1289 of_node_put(vty);
1290 break;
1291 }
1292
1293 hp = &hvsi_ports[hvsi_count];
1294 INIT_WORK(&hp->writer, hvsi_write_worker, hp);
1295 INIT_WORK(&hp->handshaker, hvsi_handshaker, hp);
1296 init_waitqueue_head(&hp->emptyq);
1297 init_waitqueue_head(&hp->stateq);
1298 spin_lock_init(&hp->lock);
1299 hp->index = hvsi_count;
1300 hp->inbuf_end = hp->inbuf;
1301 hp->state = HVSI_CLOSED;
1302 hp->vtermno = *vtermno;
1303 hp->virq = virt_irq_create_mapping(irq[0]);
1304 if (hp->virq == NO_IRQ) {
1305 printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
1306 __FUNCTION__, hp->virq);
1307 continue;
1308 } else
1309 hp->virq = irq_offset_up(hp->virq);
1310
1311 hvsi_count++;
1312 }
1313
1314 if (hvsi_count)
1315 register_console(&hvsi_con_driver);
1316 return 0;
1317}
1318console_initcall(hvsi_console_init);