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[PATCH] aic7xxx_osm build fix
[cris-mirror.git] / drivers / char / hvsi.c
blobf1f1192ba2b50ce00706f2dbb1ee9c850f338329
1 /*
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
71 struct 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 };
97 static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES];
98
99 static struct tty_driver *hvsi_driver;
100 static int hvsi_count;
101 static int (*hvsi_wait)(struct hvsi_struct *hp, int state);
102
103 enum 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
131 struct hvsi_header {
132 uint8_t type;
133 uint8_t len;
134 uint16_t seqno;
135 } __attribute__((packed));
136
137 struct 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
144 struct 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
154 struct hvsi_query {
155 uint8_t type;
156 uint8_t len;
157 uint16_t seqno;
158 uint16_t verb;
159 } __attribute__((packed));
160
161 struct 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
175 static inline int is_console(struct hvsi_struct *hp)
176 {
177 return hp->flags & HVSI_CONSOLE;
178 }
179
180 static 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
187 static 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
200 if (hp->state > (sizeof(state_names)/sizeof(char*)))
201 name = "UNKNOWN";
202
203 pr_debug("hvsi%i: state = %s\n", hp->index, name);
204 #endif /* DEBUG */
205 }
206
207 static 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
214 static 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
223 static inline int len_packet(const uint8_t *packet)
224 {
225 return (int)((struct hvsi_header *)packet)->len;
226 }
227
228 static 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
234 static 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 */
246 static 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
266 static 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
284 static 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
294 /* can't use hvc_get_chars because that strips CRs */
295 static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
296 {
297 unsigned long got;
298
299 if (plpar_hcall(H_GET_TERM_CHAR, hp->vtermno, 0, 0, 0, &got,
300 (unsigned long *)buf, (unsigned long *)buf+1) == H_Success)
301 return got;
302 return 0;
303 }
304
305 static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
306 struct tty_struct **to_hangup, struct hvsi_struct **to_handshake)
307 {
308 struct hvsi_control *header = (struct hvsi_control *)packet;
309
310 switch (header->verb) {
311 case VSV_MODEM_CTL_UPDATE:
312 if ((header->word & HVSI_TSCD) == 0) {
313 /* CD went away; no more connection */
314 pr_debug("hvsi%i: CD dropped\n", hp->index);
315 hp->mctrl &= TIOCM_CD;
316 if (!(hp->tty->flags & CLOCAL))
317 *to_hangup = hp->tty;
318 }
319 break;
320 case VSV_CLOSE_PROTOCOL:
321 pr_debug("hvsi%i: service processor came back\n", hp->index);
322 if (hp->state != HVSI_CLOSED) {
323 *to_handshake = hp;
324 }
325 break;
326 default:
327 printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ",
328 hp->index);
329 dump_packet(packet);
330 break;
331 }
332 }
333
334 static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet)
335 {
336 struct hvsi_query_response *resp = (struct hvsi_query_response *)packet;
337
338 switch (hp->state) {
339 case HVSI_WAIT_FOR_VER_RESPONSE:
340 __set_state(hp, HVSI_WAIT_FOR_VER_QUERY);
341 break;
342 case HVSI_WAIT_FOR_MCTRL_RESPONSE:
343 hp->mctrl = 0;
344 if (resp->u.mctrl_word & HVSI_TSDTR)
345 hp->mctrl |= TIOCM_DTR;
346 if (resp->u.mctrl_word & HVSI_TSCD)
347 hp->mctrl |= TIOCM_CD;
348 __set_state(hp, HVSI_OPEN);
349 break;
350 default:
351 printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index);
352 dump_packet(packet);
353 break;
354 }
355 }
356
357 /* respond to service processor's version query */
358 static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno)
359 {
360 struct hvsi_query_response packet __ALIGNED__;
361 int wrote;
362
363 packet.type = VS_QUERY_RESPONSE_PACKET_HEADER;
364 packet.len = sizeof(struct hvsi_query_response);
365 packet.seqno = atomic_inc_return(&hp->seqno);
366 packet.verb = VSV_SEND_VERSION_NUMBER;
367 packet.u.version = HVSI_VERSION;
368 packet.query_seqno = query_seqno+1;
369
370 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
371 dbg_dump_hex((uint8_t*)&packet, packet.len);
372
373 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
374 if (wrote != packet.len) {
375 printk(KERN_ERR "hvsi%i: couldn't send query response!\n",
376 hp->index);
377 return -EIO;
378 }
379
380 return 0;
381 }
382
383 static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet)
384 {
385 struct hvsi_query *query = (struct hvsi_query *)packet;
386
387 switch (hp->state) {
388 case HVSI_WAIT_FOR_VER_QUERY:
389 hvsi_version_respond(hp, query->seqno);
390 __set_state(hp, HVSI_OPEN);
391 break;
392 default:
393 printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index);
394 dump_packet(packet);
395 break;
396 }
397 }
398
399 static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len)
400 {
401 int i;
402
403 for (i=0; i < len; i++) {
404 char c = buf[i];
405 #ifdef CONFIG_MAGIC_SYSRQ
406 if (c == '\0') {
407 hp->sysrq = 1;
408 continue;
409 } else if (hp->sysrq) {
410 handle_sysrq(c, NULL, hp->tty);
411 hp->sysrq = 0;
412 continue;
413 }
414 #endif /* CONFIG_MAGIC_SYSRQ */
415 tty_insert_flip_char(hp->tty, c, 0);
416 }
417 }
418
419 /*
420 * We could get 252 bytes of data at once here. But the tty layer only
421 * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow
422 * it. Accordingly we won't send more than 128 bytes at a time to the flip
423 * buffer, which will give the tty buffer a chance to throttle us. Should the
424 * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be
425 * revisited.
426 */
427 #define TTY_THRESHOLD_THROTTLE 128
428 static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp,
429 const uint8_t *packet)
430 {
431 const struct hvsi_header *header = (const struct hvsi_header *)packet;
432 const uint8_t *data = packet + sizeof(struct hvsi_header);
433 int datalen = header->len - sizeof(struct hvsi_header);
434 int overflow = datalen - TTY_THRESHOLD_THROTTLE;
435
436 pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data);
437
438 if (datalen == 0)
439 return NULL;
440
441 if (overflow > 0) {
442 pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __FUNCTION__);
443 datalen = TTY_THRESHOLD_THROTTLE;
444 }
445
446 hvsi_insert_chars(hp, data, datalen);
447
448 if (overflow > 0) {
449 /*
450 * we still have more data to deliver, so we need to save off the
451 * overflow and send it later
452 */
453 pr_debug("%s: deferring overflow\n", __FUNCTION__);
454 memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow);
455 hp->n_throttle = overflow;
456 }
457
458 return hp->tty;
459 }
460
461 /*
462 * Returns true/false indicating data successfully read from hypervisor.
463 * Used both to get packets for tty connections and to advance the state
464 * machine during console handshaking (in which case tty = NULL and we ignore
465 * incoming data).
466 */
467 static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip,
468 struct tty_struct **hangup, struct hvsi_struct **handshake)
469 {
470 uint8_t *packet = hp->inbuf;
471 int chunklen;
472
473 *flip = NULL;
474 *hangup = NULL;
475 *handshake = NULL;
476
477 chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ);
478 if (chunklen == 0) {
479 pr_debug("%s: 0-length read\n", __FUNCTION__);
480 return 0;
481 }
482
483 pr_debug("%s: got %i bytes\n", __FUNCTION__, chunklen);
484 dbg_dump_hex(hp->inbuf_end, chunklen);
485
486 hp->inbuf_end += chunklen;
487
488 /* handle all completed packets */
489 while ((packet < hp->inbuf_end) && got_packet(hp, packet)) {
490 struct hvsi_header *header = (struct hvsi_header *)packet;
491
492 if (!is_header(packet)) {
493 printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index);
494 /* skip bytes until we find a header or run out of data */
495 while ((packet < hp->inbuf_end) && (!is_header(packet)))
496 packet++;
497 continue;
498 }
499
500 pr_debug("%s: handling %i-byte packet\n", __FUNCTION__,
501 len_packet(packet));
502 dbg_dump_packet(packet);
503
504 switch (header->type) {
505 case VS_DATA_PACKET_HEADER:
506 if (!is_open(hp))
507 break;
508 if (hp->tty == NULL)
509 break; /* no tty buffer to put data in */
510 *flip = hvsi_recv_data(hp, packet);
511 break;
512 case VS_CONTROL_PACKET_HEADER:
513 hvsi_recv_control(hp, packet, hangup, handshake);
514 break;
515 case VS_QUERY_RESPONSE_PACKET_HEADER:
516 hvsi_recv_response(hp, packet);
517 break;
518 case VS_QUERY_PACKET_HEADER:
519 hvsi_recv_query(hp, packet);
520 break;
521 default:
522 printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n",
523 hp->index, header->type);
524 dump_packet(packet);
525 break;
526 }
527
528 packet += len_packet(packet);
529
530 if (*hangup || *handshake) {
531 pr_debug("%s: hangup or handshake\n", __FUNCTION__);
532 /*
533 * we need to send the hangup now before receiving any more data.
534 * If we get "data, hangup, data", we can't deliver the second
535 * data before the hangup.
536 */
537 break;
538 }
539 }
540
541 compact_inbuf(hp, packet);
542
543 return 1;
544 }
545
546 static void hvsi_send_overflow(struct hvsi_struct *hp)
547 {
548 pr_debug("%s: delivering %i bytes overflow\n", __FUNCTION__,
549 hp->n_throttle);
550
551 hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle);
552 hp->n_throttle = 0;
553 }
554
555 /*
556 * must get all pending data because we only get an irq on empty->non-empty
557 * transition
558 */
559 static irqreturn_t hvsi_interrupt(int irq, void *arg, struct pt_regs *regs)
560 {
561 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
562 struct tty_struct *flip;
563 struct tty_struct *hangup;
564 struct hvsi_struct *handshake;
565 unsigned long flags;
566 int again = 1;
567
568 pr_debug("%s\n", __FUNCTION__);
569
570 while (again) {
571 spin_lock_irqsave(&hp->lock, flags);
572 again = hvsi_load_chunk(hp, &flip, &hangup, &handshake);
573 spin_unlock_irqrestore(&hp->lock, flags);
574
575 /*
576 * we have to call tty_flip_buffer_push() and tty_hangup() outside our
577 * spinlock. But we also have to keep going until we've read all the
578 * available data.
579 */
580
581 if (flip) {
582 /* there was data put in the tty flip buffer */
583 tty_flip_buffer_push(flip);
584 flip = NULL;
585 }
586
587 if (hangup) {
588 tty_hangup(hangup);
589 }
590
591 if (handshake) {
592 pr_debug("hvsi%i: attempting re-handshake\n", handshake->index);
593 schedule_work(&handshake->handshaker);
594 }
595 }
596
597 spin_lock_irqsave(&hp->lock, flags);
598 if (hp->tty && hp->n_throttle
599 && (!test_bit(TTY_THROTTLED, &hp->tty->flags))) {
600 /* we weren't hung up and we weren't throttled, so we can deliver the
601 * rest now */
602 flip = hp->tty;
603 hvsi_send_overflow(hp);
604 }
605 spin_unlock_irqrestore(&hp->lock, flags);
606
607 if (flip) {
608 tty_flip_buffer_push(flip);
609 }
610
611 return IRQ_HANDLED;
612 }
613
614 /* for boot console, before the irq handler is running */
615 static int __init poll_for_state(struct hvsi_struct *hp, int state)
616 {
617 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
618
619 for (;;) {
620 hvsi_interrupt(hp->virq, (void *)hp, NULL); /* get pending data */
621
622 if (hp->state == state)
623 return 0;
624
625 mdelay(5);
626 if (time_after(jiffies, end_jiffies))
627 return -EIO;
628 }
629 }
630
631 /* wait for irq handler to change our state */
632 static int wait_for_state(struct hvsi_struct *hp, int state)
633 {
634 int ret = 0;
635
636 if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT))
637 ret = -EIO;
638
639 return ret;
640 }
641
642 static int hvsi_query(struct hvsi_struct *hp, uint16_t verb)
643 {
644 struct hvsi_query packet __ALIGNED__;
645 int wrote;
646
647 packet.type = VS_QUERY_PACKET_HEADER;
648 packet.len = sizeof(struct hvsi_query);
649 packet.seqno = atomic_inc_return(&hp->seqno);
650 packet.verb = verb;
651
652 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
653 dbg_dump_hex((uint8_t*)&packet, packet.len);
654
655 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
656 if (wrote != packet.len) {
657 printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index,
658 wrote);
659 return -EIO;
660 }
661
662 return 0;
663 }
664
665 static int hvsi_get_mctrl(struct hvsi_struct *hp)
666 {
667 int ret;
668
669 set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE);
670 hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS);
671
672 ret = hvsi_wait(hp, HVSI_OPEN);
673 if (ret < 0) {
674 printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index);
675 set_state(hp, HVSI_OPEN);
676 return ret;
677 }
678
679 pr_debug("%s: mctrl 0x%x\n", __FUNCTION__, hp->mctrl);
680
681 return 0;
682 }
683
684 /* note that we can only set DTR */
685 static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl)
686 {
687 struct hvsi_control packet __ALIGNED__;
688 int wrote;
689
690 packet.type = VS_CONTROL_PACKET_HEADER,
691 packet.seqno = atomic_inc_return(&hp->seqno);
692 packet.len = sizeof(struct hvsi_control);
693 packet.verb = VSV_SET_MODEM_CTL;
694 packet.mask = HVSI_TSDTR;
695
696 if (mctrl & TIOCM_DTR)
697 packet.word = HVSI_TSDTR;
698
699 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
700 dbg_dump_hex((uint8_t*)&packet, packet.len);
701
702 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
703 if (wrote != packet.len) {
704 printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index);
705 return -EIO;
706 }
707
708 return 0;
709 }
710
711 static void hvsi_drain_input(struct hvsi_struct *hp)
712 {
713 uint8_t buf[HVSI_MAX_READ] __ALIGNED__;
714 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT;
715
716 while (time_before(end_jiffies, jiffies))
717 if (0 == hvsi_read(hp, buf, HVSI_MAX_READ))
718 break;
719 }
720
721 static int hvsi_handshake(struct hvsi_struct *hp)
722 {
723 int ret;
724
725 /*
726 * We could have a CLOSE or other data waiting for us before we even try
727 * to open; try to throw it all away so we don't get confused. (CLOSE
728 * is the first message sent up the pipe when the FSP comes online. We
729 * need to distinguish between "it came up a while ago and we're the first
730 * user" and "it was just reset before it saw our handshake packet".)
731 */
732 hvsi_drain_input(hp);
733
734 set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE);
735 ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER);
736 if (ret < 0) {
737 printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index);
738 return ret;
739 }
740
741 ret = hvsi_wait(hp, HVSI_OPEN);
742 if (ret < 0)
743 return ret;
744
745 return 0;
746 }
747
748 static void hvsi_handshaker(void *arg)
749 {
750 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
751
752 if (hvsi_handshake(hp) >= 0)
753 return;
754
755 printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index);
756 if (is_console(hp)) {
757 /*
758 * ttys will re-attempt the handshake via hvsi_open, but
759 * the console will not.
760 */
761 printk(KERN_ERR "hvsi%i: lost console!\n", hp->index);
762 }
763 }
764
765 static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count)
766 {
767 struct hvsi_data packet __ALIGNED__;
768 int ret;
769
770 BUG_ON(count > HVSI_MAX_OUTGOING_DATA);
771
772 packet.type = VS_DATA_PACKET_HEADER;
773 packet.seqno = atomic_inc_return(&hp->seqno);
774 packet.len = count + sizeof(struct hvsi_header);
775 memcpy(&packet.data, buf, count);
776
777 ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
778 if (ret == packet.len) {
779 /* return the number of chars written, not the packet length */
780 return count;
781 }
782 return ret; /* return any errors */
783 }
784
785 static void hvsi_close_protocol(struct hvsi_struct *hp)
786 {
787 struct hvsi_control packet __ALIGNED__;
788
789 packet.type = VS_CONTROL_PACKET_HEADER;
790 packet.seqno = atomic_inc_return(&hp->seqno);
791 packet.len = 6;
792 packet.verb = VSV_CLOSE_PROTOCOL;
793
794 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len);
795 dbg_dump_hex((uint8_t*)&packet, packet.len);
796
797 hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
798 }
799
800 static int hvsi_open(struct tty_struct *tty, struct file *filp)
801 {
802 struct hvsi_struct *hp;
803 unsigned long flags;
804 int line = tty->index;
805 int ret;
806
807 pr_debug("%s\n", __FUNCTION__);
808
809 if (line < 0 || line >= hvsi_count)
810 return -ENODEV;
811 hp = &hvsi_ports[line];
812
813 tty->driver_data = hp;
814 tty->low_latency = 1; /* avoid throttle/tty_flip_buffer_push race */
815
816 mb();
817 if (hp->state == HVSI_FSP_DIED)
818 return -EIO;
819
820 spin_lock_irqsave(&hp->lock, flags);
821 hp->tty = tty;
822 hp->count++;
823 atomic_set(&hp->seqno, 0);
824 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
825 spin_unlock_irqrestore(&hp->lock, flags);
826
827 if (is_console(hp))
828 return 0; /* this has already been handshaked as the console */
829
830 ret = hvsi_handshake(hp);
831 if (ret < 0) {
832 printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name);
833 return ret;
834 }
835
836 ret = hvsi_get_mctrl(hp);
837 if (ret < 0) {
838 printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name);
839 return ret;
840 }
841
842 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
843 if (ret < 0) {
844 printk(KERN_ERR "%s: couldn't set DTR\n", tty->name);
845 return ret;
846 }
847
848 return 0;
849 }
850
851 /* wait for hvsi_write_worker to empty hp->outbuf */
852 static void hvsi_flush_output(struct hvsi_struct *hp)
853 {
854 wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT);
855
856 /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */
857 cancel_delayed_work(&hp->writer);
858 flush_scheduled_work();
859
860 /*
861 * it's also possible that our timeout expired and hvsi_write_worker
862 * didn't manage to push outbuf. poof.
863 */
864 hp->n_outbuf = 0;
865 }
866
867 static void hvsi_close(struct tty_struct *tty, struct file *filp)
868 {
869 struct hvsi_struct *hp = tty->driver_data;
870 unsigned long flags;
871
872 pr_debug("%s\n", __FUNCTION__);
873
874 if (tty_hung_up_p(filp))
875 return;
876
877 spin_lock_irqsave(&hp->lock, flags);
878
879 if (--hp->count == 0) {
880 hp->tty = NULL;
881 hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */
882
883 /* only close down connection if it is not the console */
884 if (!is_console(hp)) {
885 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */
886 __set_state(hp, HVSI_CLOSED);
887 /*
888 * any data delivered to the tty layer after this will be
889 * discarded (except for XON/XOFF)
890 */
891 tty->closing = 1;
892
893 spin_unlock_irqrestore(&hp->lock, flags);
894
895 /* let any existing irq handlers finish. no more will start. */
896 synchronize_irq(hp->virq);
897
898 /* hvsi_write_worker will re-schedule until outbuf is empty. */
899 hvsi_flush_output(hp);
900
901 /* tell FSP to stop sending data */
902 hvsi_close_protocol(hp);
903
904 /*
905 * drain anything FSP is still in the middle of sending, and let
906 * hvsi_handshake drain the rest on the next open.
907 */
908 hvsi_drain_input(hp);
909
910 spin_lock_irqsave(&hp->lock, flags);
911 }
912 } else if (hp->count < 0)
913 printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n",
914 hp - hvsi_ports, hp->count);
915
916 spin_unlock_irqrestore(&hp->lock, flags);
917 }
918
919 static void hvsi_hangup(struct tty_struct *tty)
920 {
921 struct hvsi_struct *hp = tty->driver_data;
922 unsigned long flags;
923
924 pr_debug("%s\n", __FUNCTION__);
925
926 spin_lock_irqsave(&hp->lock, flags);
927
928 hp->count = 0;
929 hp->n_outbuf = 0;
930 hp->tty = NULL;
931
932 spin_unlock_irqrestore(&hp->lock, flags);
933 }
934
935 /* called with hp->lock held */
936 static void hvsi_push(struct hvsi_struct *hp)
937 {
938 int n;
939
940 if (hp->n_outbuf <= 0)
941 return;
942
943 n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf);
944 if (n > 0) {
945 /* success */
946 pr_debug("%s: wrote %i chars\n", __FUNCTION__, n);
947 hp->n_outbuf = 0;
948 } else if (n == -EIO) {
949 __set_state(hp, HVSI_FSP_DIED);
950 printk(KERN_ERR "hvsi%i: service processor died\n", hp->index);
951 }
952 }
953
954 /* hvsi_write_worker will keep rescheduling itself until outbuf is empty */
955 static void hvsi_write_worker(void *arg)
956 {
957 struct hvsi_struct *hp = (struct hvsi_struct *)arg;
958 unsigned long flags;
959 #ifdef DEBUG
960 static long start_j = 0;
961
962 if (start_j == 0)
963 start_j = jiffies;
964 #endif /* DEBUG */
965
966 spin_lock_irqsave(&hp->lock, flags);
967
968 pr_debug("%s: %i chars in buffer\n", __FUNCTION__, hp->n_outbuf);
969
970 if (!is_open(hp)) {
971 /*
972 * We could have a non-open connection if the service processor died
973 * while we were busily scheduling ourselves. In that case, it could
974 * be minutes before the service processor comes back, so only try
975 * again once a second.
976 */
977 schedule_delayed_work(&hp->writer, HZ);
978 goto out;
979 }
980
981 hvsi_push(hp);
982 if (hp->n_outbuf > 0)
983 schedule_delayed_work(&hp->writer, 10);
984 else {
985 #ifdef DEBUG
986 pr_debug("%s: outbuf emptied after %li jiffies\n", __FUNCTION__,
987 jiffies - start_j);
988 start_j = 0;
989 #endif /* DEBUG */
990 wake_up_all(&hp->emptyq);
991 if (test_bit(TTY_DO_WRITE_WAKEUP, &hp->tty->flags)
992 && hp->tty->ldisc.write_wakeup)
993 hp->tty->ldisc.write_wakeup(hp->tty);
994 wake_up_interruptible(&hp->tty->write_wait);
995 }
996
997 out:
998 spin_unlock_irqrestore(&hp->lock, flags);
999 }
1000
1001 static int hvsi_write_room(struct tty_struct *tty)
1002 {
1003 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1004
1005 return N_OUTBUF - hp->n_outbuf;
1006 }
1007
1008 static int hvsi_chars_in_buffer(struct tty_struct *tty)
1009 {
1010 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1011
1012 return hp->n_outbuf;
1013 }
1014
1015 static int hvsi_write(struct tty_struct *tty,
1016 const unsigned char *buf, int count)
1017 {
1018 struct hvsi_struct *hp = tty->driver_data;
1019 const char *source = buf;
1020 unsigned long flags;
1021 int total = 0;
1022 int origcount = count;
1023
1024 spin_lock_irqsave(&hp->lock, flags);
1025
1026 pr_debug("%s: %i chars in buffer\n", __FUNCTION__, hp->n_outbuf);
1027
1028 if (!is_open(hp)) {
1029 /* we're either closing or not yet open; don't accept data */
1030 pr_debug("%s: not open\n", __FUNCTION__);
1031 goto out;
1032 }
1033
1034 /*
1035 * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf
1036 * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
1037 * will see there is no room in outbuf and return.
1038 */
1039 while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) {
1040 int chunksize = min(count, hvsi_write_room(hp->tty));
1041
1042 BUG_ON(hp->n_outbuf < 0);
1043 memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
1044 hp->n_outbuf += chunksize;
1045
1046 total += chunksize;
1047 source += chunksize;
1048 count -= chunksize;
1049 hvsi_push(hp);
1050 }
1051
1052 if (hp->n_outbuf > 0) {
1053 /*
1054 * we weren't able to write it all to the hypervisor.
1055 * schedule another push attempt.
1056 */
1057 schedule_delayed_work(&hp->writer, 10);
1058 }
1059
1060 out:
1061 spin_unlock_irqrestore(&hp->lock, flags);
1062
1063 if (total != origcount)
1064 pr_debug("%s: wanted %i, only wrote %i\n", __FUNCTION__, origcount,
1065 total);
1066
1067 return total;
1068 }
1069
1070 /*
1071 * I have never seen throttle or unthrottle called, so this little throttle
1072 * buffering scheme may or may not work.
1073 */
1074 static void hvsi_throttle(struct tty_struct *tty)
1075 {
1076 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1077
1078 pr_debug("%s\n", __FUNCTION__);
1079
1080 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE);
1081 }
1082
1083 static void hvsi_unthrottle(struct tty_struct *tty)
1084 {
1085 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1086 unsigned long flags;
1087 int shouldflip = 0;
1088
1089 pr_debug("%s\n", __FUNCTION__);
1090
1091 spin_lock_irqsave(&hp->lock, flags);
1092 if (hp->n_throttle) {
1093 hvsi_send_overflow(hp);
1094 shouldflip = 1;
1095 }
1096 spin_unlock_irqrestore(&hp->lock, flags);
1097
1098 if (shouldflip)
1099 tty_flip_buffer_push(hp->tty);
1100
1101 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
1102 }
1103
1104 static int hvsi_tiocmget(struct tty_struct *tty, struct file *file)
1105 {
1106 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1107
1108 hvsi_get_mctrl(hp);
1109 return hp->mctrl;
1110 }
1111
1112 static int hvsi_tiocmset(struct tty_struct *tty, struct file *file,
1113 unsigned int set, unsigned int clear)
1114 {
1115 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data;
1116 unsigned long flags;
1117 uint16_t new_mctrl;
1118
1119 /* we can only alter DTR */
1120 clear &= TIOCM_DTR;
1121 set &= TIOCM_DTR;
1122
1123 spin_lock_irqsave(&hp->lock, flags);
1124
1125 new_mctrl = (hp->mctrl & ~clear) | set;
1126
1127 if (hp->mctrl != new_mctrl) {
1128 hvsi_set_mctrl(hp, new_mctrl);
1129 hp->mctrl = new_mctrl;
1130 }
1131 spin_unlock_irqrestore(&hp->lock, flags);
1132
1133 return 0;
1134 }
1135
1136
1137 static struct tty_operations hvsi_ops = {
1138 .open = hvsi_open,
1139 .close = hvsi_close,
1140 .write = hvsi_write,
1141 .hangup = hvsi_hangup,
1142 .write_room = hvsi_write_room,
1143 .chars_in_buffer = hvsi_chars_in_buffer,
1144 .throttle = hvsi_throttle,
1145 .unthrottle = hvsi_unthrottle,
1146 .tiocmget = hvsi_tiocmget,
1147 .tiocmset = hvsi_tiocmset,
1148 };
1149
1150 static int __init hvsi_init(void)
1151 {
1152 int i;
1153
1154 hvsi_driver = alloc_tty_driver(hvsi_count);
1155 if (!hvsi_driver)
1156 return -ENOMEM;
1157
1158 hvsi_driver->owner = THIS_MODULE;
1159 hvsi_driver->devfs_name = "hvsi/";
1160 hvsi_driver->driver_name = "hvsi";
1161 hvsi_driver->name = "hvsi";
1162 hvsi_driver->major = HVSI_MAJOR;
1163 hvsi_driver->minor_start = HVSI_MINOR;
1164 hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM;
1165 hvsi_driver->init_termios = tty_std_termios;
1166 hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
1167 hvsi_driver->flags = TTY_DRIVER_REAL_RAW;
1168 tty_set_operations(hvsi_driver, &hvsi_ops);
1169
1170 for (i=0; i < hvsi_count; i++) {
1171 struct hvsi_struct *hp = &hvsi_ports[i];
1172 int ret = 1;
1173
1174 ret = request_irq(hp->virq, hvsi_interrupt, SA_INTERRUPT, "hvsi", hp);
1175 if (ret)
1176 printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n",
1177 hp->virq, ret);
1178 }
1179 hvsi_wait = wait_for_state; /* irqs active now */
1180
1181 if (tty_register_driver(hvsi_driver))
1182 panic("Couldn't register hvsi console driver\n");
1183
1184 printk(KERN_INFO "HVSI: registered %i devices\n", hvsi_count);
1185
1186 return 0;
1187 }
1188 device_initcall(hvsi_init);
1189
1190 /***** console (not tty) code: *****/
1191
1192 static void hvsi_console_print(struct console *console, const char *buf,
1193 unsigned int count)
1194 {
1195 struct hvsi_struct *hp = &hvsi_ports[console->index];
1196 char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__;
1197 unsigned int i = 0, n = 0;
1198 int ret, donecr = 0;
1199
1200 mb();
1201 if (!is_open(hp))
1202 return;
1203
1204 /*
1205 * ugh, we have to translate LF -> CRLF ourselves, in place.
1206 * copied from hvc_console.c:
1207 */
1208 while (count > 0 || i > 0) {
1209 if (count > 0 && i < sizeof(c)) {
1210 if (buf[n] == '\n' && !donecr) {
1211 c[i++] = '\r';
1212 donecr = 1;
1213 } else {
1214 c[i++] = buf[n++];
1215 donecr = 0;
1216 --count;
1217 }
1218 } else {
1219 ret = hvsi_put_chars(hp, c, i);
1220 if (ret < 0)
1221 i = 0;
1222 i -= ret;
1223 }
1224 }
1225 }
1226
1227 static struct tty_driver *hvsi_console_device(struct console *console,
1228 int *index)
1229 {
1230 *index = console->index;
1231 return hvsi_driver;
1232 }
1233
1234 static int __init hvsi_console_setup(struct console *console, char *options)
1235 {
1236 struct hvsi_struct *hp = &hvsi_ports[console->index];
1237 int ret;
1238
1239 if (console->index < 0 || console->index >= hvsi_count)
1240 return -1;
1241
1242 /* give the FSP a chance to change the baud rate when we re-open */
1243 hvsi_close_protocol(hp);
1244
1245 ret = hvsi_handshake(hp);
1246 if (ret < 0)
1247 return ret;
1248
1249 ret = hvsi_get_mctrl(hp);
1250 if (ret < 0)
1251 return ret;
1252
1253 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR);
1254 if (ret < 0)
1255 return ret;
1256
1257 hp->flags |= HVSI_CONSOLE;
1258
1259 return 0;
1260 }
1261
1262 static struct console hvsi_con_driver = {
1263 .name = "hvsi",
1264 .write = hvsi_console_print,
1265 .device = hvsi_console_device,
1266 .setup = hvsi_console_setup,
1267 .flags = CON_PRINTBUFFER,
1268 .index = -1,
1269 };
1270
1271 static int __init hvsi_console_init(void)
1272 {
1273 struct device_node *vty;
1274
1275 hvsi_wait = poll_for_state; /* no irqs yet; must poll */
1276
1277 /* search device tree for vty nodes */
1278 for (vty = of_find_compatible_node(NULL, "serial", "hvterm-protocol");
1279 vty != NULL;
1280 vty = of_find_compatible_node(vty, "serial", "hvterm-protocol")) {
1281 struct hvsi_struct *hp;
1282 uint32_t *vtermno;
1283 uint32_t *irq;
1284
1285 vtermno = (uint32_t *)get_property(vty, "reg", NULL);
1286 irq = (uint32_t *)get_property(vty, "interrupts", NULL);
1287 if (!vtermno || !irq)
1288 continue;
1289
1290 if (hvsi_count >= MAX_NR_HVSI_CONSOLES) {
1291 of_node_put(vty);
1292 break;
1293 }
1294
1295 hp = &hvsi_ports[hvsi_count];
1296 INIT_WORK(&hp->writer, hvsi_write_worker, hp);
1297 INIT_WORK(&hp->handshaker, hvsi_handshaker, hp);
1298 init_waitqueue_head(&hp->emptyq);
1299 init_waitqueue_head(&hp->stateq);
1300 spin_lock_init(&hp->lock);
1301 hp->index = hvsi_count;
1302 hp->inbuf_end = hp->inbuf;
1303 hp->state = HVSI_CLOSED;
1304 hp->vtermno = *vtermno;
1305 hp->virq = virt_irq_create_mapping(irq[0]);
1306 if (hp->virq == NO_IRQ) {
1307 printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
1308 __FUNCTION__, hp->virq);
1309 continue;
1310 } else
1311 hp->virq = irq_offset_up(hp->virq);
1312
1313 hvsi_count++;
1314 }
1315
1316 if (hvsi_count)
1317 register_console(&hvsi_con_driver);
1318 return 0;
1319 }
1320 console_initcall(hvsi_console_init);
CRIS linux kernel tree