powerpc/hvsi: Avoid calculating possibly-invalid address
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / char / hvsi.c
CommitLineData
1da177e4
LT
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>
1da177e4
LT
42#include <linux/spinlock.h>
43#include <linux/sysrq.h>
44#include <linux/tty.h>
45#include <linux/tty_flip.h>
46#include <asm/hvcall.h>
47#include <asm/hvconsole.h>
48#include <asm/prom.h>
49#include <asm/uaccess.h>
50#include <asm/vio.h>
51#include <asm/param.h>
52
53#define HVSI_MAJOR 229
54#define HVSI_MINOR 128
55#define MAX_NR_HVSI_CONSOLES 4
56
57#define HVSI_TIMEOUT (5*HZ)
58#define HVSI_VERSION 1
59#define HVSI_MAX_PACKET 256
60#define HVSI_MAX_READ 16
61#define HVSI_MAX_OUTGOING_DATA 12
62#define N_OUTBUF 12
63
64/*
65 * we pass data via two 8-byte registers, so we would like our char arrays
66 * properly aligned for those loads.
67 */
68#define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
69
70struct hvsi_struct {
c4028958 71 struct delayed_work writer;
1da177e4
LT
72 struct work_struct handshaker;
73 wait_queue_head_t emptyq; /* woken when outbuf is emptied */
74 wait_queue_head_t stateq; /* woken when HVSI state changes */
75 spinlock_t lock;
76 int index;
77 struct tty_struct *tty;
3d26825e 78 int count;
1da177e4
LT
79 uint8_t throttle_buf[128];
80 uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */
81 /* inbuf is for packet reassembly. leave a little room for leftovers. */
82 uint8_t inbuf[HVSI_MAX_PACKET + HVSI_MAX_READ];
83 uint8_t *inbuf_end;
84 int n_throttle;
85 int n_outbuf;
86 uint32_t vtermno;
87 uint32_t virq;
88 atomic_t seqno; /* HVSI packet sequence number */
89 uint16_t mctrl;
90 uint8_t state; /* HVSI protocol state */
91 uint8_t flags;
92#ifdef CONFIG_MAGIC_SYSRQ
93 uint8_t sysrq;
94#endif /* CONFIG_MAGIC_SYSRQ */
95};
96static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES];
97
98static struct tty_driver *hvsi_driver;
99static int hvsi_count;
100static int (*hvsi_wait)(struct hvsi_struct *hp, int state);
101
102enum HVSI_PROTOCOL_STATE {
103 HVSI_CLOSED,
104 HVSI_WAIT_FOR_VER_RESPONSE,
105 HVSI_WAIT_FOR_VER_QUERY,
106 HVSI_OPEN,
107 HVSI_WAIT_FOR_MCTRL_RESPONSE,
108 HVSI_FSP_DIED,
109};
110#define HVSI_CONSOLE 0x1
111
112#define VS_DATA_PACKET_HEADER 0xff
113#define VS_CONTROL_PACKET_HEADER 0xfe
114#define VS_QUERY_PACKET_HEADER 0xfd
115#define VS_QUERY_RESPONSE_PACKET_HEADER 0xfc
116
117/* control verbs */
118#define VSV_SET_MODEM_CTL 1 /* to service processor only */
119#define VSV_MODEM_CTL_UPDATE 2 /* from service processor only */
120#define VSV_CLOSE_PROTOCOL 3
121
122/* query verbs */
123#define VSV_SEND_VERSION_NUMBER 1
124#define VSV_SEND_MODEM_CTL_STATUS 2
125
126/* yes, these masks are not consecutive. */
127#define HVSI_TSDTR 0x01
128#define HVSI_TSCD 0x20
129
130struct hvsi_header {
131 uint8_t type;
132 uint8_t len;
133 uint16_t seqno;
134} __attribute__((packed));
135
136struct hvsi_data {
137 uint8_t type;
138 uint8_t len;
139 uint16_t seqno;
140 uint8_t data[HVSI_MAX_OUTGOING_DATA];
141} __attribute__((packed));
142
143struct hvsi_control {
144 uint8_t type;
145 uint8_t len;
146 uint16_t seqno;
147 uint16_t verb;
148 /* optional depending on verb: */
149 uint32_t word;
150 uint32_t mask;
151} __attribute__((packed));
152
153struct hvsi_query {
154 uint8_t type;
155 uint8_t len;
156 uint16_t seqno;
157 uint16_t verb;
158} __attribute__((packed));
159
160struct hvsi_query_response {
161 uint8_t type;
162 uint8_t len;
163 uint16_t seqno;
164 uint16_t verb;
165 uint16_t query_seqno;
166 union {
167 uint8_t version;
168 uint32_t mctrl_word;
169 } u;
170} __attribute__((packed));
171
172
173
174static inline int is_console(struct hvsi_struct *hp)
175{
176 return hp->flags & HVSI_CONSOLE;
177}
178
179static inline int is_open(struct hvsi_struct *hp)
180{
181 /* if we're waiting for an mctrl then we're already open */
182 return (hp->state == HVSI_OPEN)
183 || (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE);
184}
185
186static inline void print_state(struct hvsi_struct *hp)
187{
188#ifdef DEBUG
189 static const char *state_names[] = {
190 "HVSI_CLOSED",
191 "HVSI_WAIT_FOR_VER_RESPONSE",
192 "HVSI_WAIT_FOR_VER_QUERY",
193 "HVSI_OPEN",
194 "HVSI_WAIT_FOR_MCTRL_RESPONSE",
195 "HVSI_FSP_DIED",
196 };
197 const char *name = state_names[hp->state];
198
fe971071 199 if (hp->state > ARRAY_SIZE(state_names))
1da177e4
LT
200 name = "UNKNOWN";
201
202 pr_debug("hvsi%i: state = %s\n", hp->index, name);
203#endif /* DEBUG */
204}
205
206static inline void __set_state(struct hvsi_struct *hp, int state)
207{
208 hp->state = state;
209 print_state(hp);
210 wake_up_all(&hp->stateq);
211}
212
213static inline void set_state(struct hvsi_struct *hp, int state)
214{
215 unsigned long flags;
216
217 spin_lock_irqsave(&hp->lock, flags);
218 __set_state(hp, state);
219 spin_unlock_irqrestore(&hp->lock, flags);
220}
221
222static inline int len_packet(const uint8_t *packet)
223{
224 return (int)((struct hvsi_header *)packet)->len;
225}
226
227static inline int is_header(const uint8_t *packet)
228{
229 struct hvsi_header *header = (struct hvsi_header *)packet;
230 return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER;
231}
232
233static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet)
234{
235 if (hp->inbuf_end < packet + sizeof(struct hvsi_header))
236 return 0; /* don't even have the packet header */
237
238 if (hp->inbuf_end < (packet + len_packet(packet)))
239 return 0; /* don't have the rest of the packet */
240
241 return 1;
242}
243
244/* shift remaining bytes in packetbuf down */
245static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to)
246{
247 int remaining = (int)(hp->inbuf_end - read_to);
248
bf9d8929 249 pr_debug("%s: %i chars remain\n", __func__, remaining);
1da177e4
LT
250
251 if (read_to != hp->inbuf)
252 memmove(hp->inbuf, read_to, remaining);
253
254 hp->inbuf_end = hp->inbuf + remaining;
255}
256
257#ifdef DEBUG
258#define dbg_dump_packet(packet) dump_packet(packet)
259#define dbg_dump_hex(data, len) dump_hex(data, len)
260#else
261#define dbg_dump_packet(packet) do { } while (0)
262#define dbg_dump_hex(data, len) do { } while (0)
263#endif
264
265static void dump_hex(const uint8_t *data, int len)
266{
267 int i;
268
269 printk(" ");
270 for (i=0; i < len; i++)
271 printk("%.2x", data[i]);
272
273 printk("\n ");
274 for (i=0; i < len; i++) {
275 if (isprint(data[i]))
276 printk("%c", data[i]);
277 else
278 printk(".");
279 }
280 printk("\n");
281}
282
283static void dump_packet(uint8_t *packet)
284{
285 struct hvsi_header *header = (struct hvsi_header *)packet;
286
287 printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len,
288 header->seqno);
289
290 dump_hex(packet, header->len);
291}
292
1da177e4
LT
293static int hvsi_read(struct hvsi_struct *hp, char *buf, int count)
294{
295 unsigned long got;
296
88de0be0
MM
297 got = hvc_get_chars(hp->vtermno, buf, count);
298
299 return got;
1da177e4
LT
300}
301
302static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet,
303 struct tty_struct **to_hangup, struct hvsi_struct **to_handshake)
304{
305 struct hvsi_control *header = (struct hvsi_control *)packet;
306
307 switch (header->verb) {
308 case VSV_MODEM_CTL_UPDATE:
309 if ((header->word & HVSI_TSCD) == 0) {
310 /* CD went away; no more connection */
311 pr_debug("hvsi%i: CD dropped\n", hp->index);
312 hp->mctrl &= TIOCM_CD;
229395c9
LV
313 /* If userland hasn't done an open(2) yet, hp->tty is NULL. */
314 if (hp->tty && !(hp->tty->flags & CLOCAL))
1da177e4
LT
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
bf9d8929 368 pr_debug("%s: sending %i bytes\n", __func__, packet.len);
1da177e4
LT
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) {
7d12e780 408 handle_sysrq(c, hp->tty);
1da177e4
LT
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) {
bf9d8929 440 pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__);
1da177e4
LT
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 */
bf9d8929 451 pr_debug("%s: deferring overflow\n", __func__);
1da177e4
LT
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) {
bf9d8929 477 pr_debug("%s: 0-length read\n", __func__);
1da177e4
LT
478 return 0;
479 }
480
bf9d8929 481 pr_debug("%s: got %i bytes\n", __func__, chunklen);
1da177e4
LT
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
bf9d8929 498 pr_debug("%s: handling %i-byte packet\n", __func__,
1da177e4
LT
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) {
bf9d8929 529 pr_debug("%s: hangup or handshake\n", __func__);
1da177e4
LT
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{
bf9d8929 546 pr_debug("%s: delivering %i bytes overflow\n", __func__,
1da177e4
LT
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 */
7d12e780 557static irqreturn_t hvsi_interrupt(int irq, void *arg)
1da177e4
LT
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
bf9d8929 566 pr_debug("%s\n", __func__);
1da177e4
LT
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 (;;) {
7d12e780 618 hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */
1da177e4
LT
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
bf9d8929 650 pr_debug("%s: sending %i bytes\n", __func__, packet.len);
1da177e4
LT
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
bf9d8929 677 pr_debug("%s: mctrl 0x%x\n", __func__, hp->mctrl);
1da177e4
LT
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
bf9d8929 697 pr_debug("%s: sending %i bytes\n", __func__, packet.len);
1da177e4
LT
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
c4028958 746static void hvsi_handshaker(struct work_struct *work)
1da177e4 747{
c4028958
DH
748 struct hvsi_struct *hp =
749 container_of(work, struct hvsi_struct, handshaker);
1da177e4
LT
750
751 if (hvsi_handshake(hp) >= 0)
752 return;
753
754 printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index);
755 if (is_console(hp)) {
756 /*
757 * ttys will re-attempt the handshake via hvsi_open, but
758 * the console will not.
759 */
760 printk(KERN_ERR "hvsi%i: lost console!\n", hp->index);
761 }
762}
763
764static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count)
765{
766 struct hvsi_data packet __ALIGNED__;
767 int ret;
768
769 BUG_ON(count > HVSI_MAX_OUTGOING_DATA);
770
771 packet.type = VS_DATA_PACKET_HEADER;
772 packet.seqno = atomic_inc_return(&hp->seqno);
773 packet.len = count + sizeof(struct hvsi_header);
774 memcpy(&packet.data, buf, count);
775
776 ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
777 if (ret == packet.len) {
778 /* return the number of chars written, not the packet length */
779 return count;
780 }
781 return ret; /* return any errors */
782}
783
784static void hvsi_close_protocol(struct hvsi_struct *hp)
785{
786 struct hvsi_control packet __ALIGNED__;
787
788 packet.type = VS_CONTROL_PACKET_HEADER;
789 packet.seqno = atomic_inc_return(&hp->seqno);
790 packet.len = 6;
791 packet.verb = VSV_CLOSE_PROTOCOL;
792
bf9d8929 793 pr_debug("%s: sending %i bytes\n", __func__, packet.len);
1da177e4
LT
794 dbg_dump_hex((uint8_t*)&packet, packet.len);
795
796 hvc_put_chars(hp->vtermno, (char *)&packet, packet.len);
797}
798
799static int hvsi_open(struct tty_struct *tty, struct file *filp)
800{
801 struct hvsi_struct *hp;
802 unsigned long flags;
803 int line = tty->index;
804 int ret;
805
bf9d8929 806 pr_debug("%s\n", __func__);
1da177e4
LT
807
808 if (line < 0 || line >= hvsi_count)
809 return -ENODEV;
810 hp = &hvsi_ports[line];
811
812 tty->driver_data = hp;
1da177e4
LT
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
bf9d8929 870 pr_debug("%s\n", __func__);
1da177e4
LT
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
bf9d8929 922 pr_debug("%s\n", __func__);
1da177e4
LT
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 */
bf9d8929 944 pr_debug("%s: wrote %i chars\n", __func__, n);
1da177e4
LT
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 */
c4028958 953static void hvsi_write_worker(struct work_struct *work)
1da177e4 954{
c4028958
DH
955 struct hvsi_struct *hp =
956 container_of(work, struct hvsi_struct, writer.work);
1da177e4
LT
957 unsigned long flags;
958#ifdef DEBUG
959 static long start_j = 0;
960
961 if (start_j == 0)
962 start_j = jiffies;
963#endif /* DEBUG */
964
965 spin_lock_irqsave(&hp->lock, flags);
966
bf9d8929 967 pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
1da177e4
LT
968
969 if (!is_open(hp)) {
970 /*
971 * We could have a non-open connection if the service processor died
972 * while we were busily scheduling ourselves. In that case, it could
973 * be minutes before the service processor comes back, so only try
974 * again once a second.
975 */
976 schedule_delayed_work(&hp->writer, HZ);
977 goto out;
978 }
979
980 hvsi_push(hp);
981 if (hp->n_outbuf > 0)
982 schedule_delayed_work(&hp->writer, 10);
983 else {
984#ifdef DEBUG
bf9d8929 985 pr_debug("%s: outbuf emptied after %li jiffies\n", __func__,
1da177e4
LT
986 jiffies - start_j);
987 start_j = 0;
988#endif /* DEBUG */
989 wake_up_all(&hp->emptyq);
64e0cc38 990 tty_wakeup(hp->tty);
1da177e4
LT
991 }
992
993out:
994 spin_unlock_irqrestore(&hp->lock, flags);
995}
996
997static int hvsi_write_room(struct tty_struct *tty)
998{
c9f19e96 999 struct hvsi_struct *hp = tty->driver_data;
1da177e4
LT
1000
1001 return N_OUTBUF - hp->n_outbuf;
1002}
1003
1004static int hvsi_chars_in_buffer(struct tty_struct *tty)
1005{
c9f19e96 1006 struct hvsi_struct *hp = tty->driver_data;
1da177e4
LT
1007
1008 return hp->n_outbuf;
1009}
1010
1011static int hvsi_write(struct tty_struct *tty,
1012 const unsigned char *buf, int count)
1013{
1014 struct hvsi_struct *hp = tty->driver_data;
1015 const char *source = buf;
1016 unsigned long flags;
1017 int total = 0;
1018 int origcount = count;
1019
1020 spin_lock_irqsave(&hp->lock, flags);
1021
bf9d8929 1022 pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf);
1da177e4
LT
1023
1024 if (!is_open(hp)) {
1025 /* we're either closing or not yet open; don't accept data */
bf9d8929 1026 pr_debug("%s: not open\n", __func__);
1da177e4
LT
1027 goto out;
1028 }
1029
1030 /*
1031 * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf
1032 * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls
1033 * will see there is no room in outbuf and return.
1034 */
1035 while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) {
1036 int chunksize = min(count, hvsi_write_room(hp->tty));
1037
1038 BUG_ON(hp->n_outbuf < 0);
1039 memcpy(hp->outbuf + hp->n_outbuf, source, chunksize);
1040 hp->n_outbuf += chunksize;
1041
1042 total += chunksize;
1043 source += chunksize;
1044 count -= chunksize;
1045 hvsi_push(hp);
1046 }
1047
1048 if (hp->n_outbuf > 0) {
1049 /*
1050 * we weren't able to write it all to the hypervisor.
1051 * schedule another push attempt.
1052 */
1053 schedule_delayed_work(&hp->writer, 10);
1054 }
1055
1056out:
1057 spin_unlock_irqrestore(&hp->lock, flags);
1058
1059 if (total != origcount)
bf9d8929 1060 pr_debug("%s: wanted %i, only wrote %i\n", __func__, origcount,
1da177e4
LT
1061 total);
1062
1063 return total;
1064}
1065
1066/*
1067 * I have never seen throttle or unthrottle called, so this little throttle
1068 * buffering scheme may or may not work.
1069 */
1070static void hvsi_throttle(struct tty_struct *tty)
1071{
c9f19e96 1072 struct hvsi_struct *hp = tty->driver_data;
1da177e4 1073
bf9d8929 1074 pr_debug("%s\n", __func__);
1da177e4
LT
1075
1076 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE);
1077}
1078
1079static void hvsi_unthrottle(struct tty_struct *tty)
1080{
c9f19e96 1081 struct hvsi_struct *hp = tty->driver_data;
1da177e4
LT
1082 unsigned long flags;
1083 int shouldflip = 0;
1084
bf9d8929 1085 pr_debug("%s\n", __func__);
1da177e4
LT
1086
1087 spin_lock_irqsave(&hp->lock, flags);
1088 if (hp->n_throttle) {
1089 hvsi_send_overflow(hp);
1090 shouldflip = 1;
1091 }
1092 spin_unlock_irqrestore(&hp->lock, flags);
1093
1094 if (shouldflip)
1095 tty_flip_buffer_push(hp->tty);
1096
1097 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE);
1098}
1099
1100static int hvsi_tiocmget(struct tty_struct *tty, struct file *file)
1101{
c9f19e96 1102 struct hvsi_struct *hp = tty->driver_data;
1da177e4
LT
1103
1104 hvsi_get_mctrl(hp);
1105 return hp->mctrl;
1106}
1107
1108static int hvsi_tiocmset(struct tty_struct *tty, struct file *file,
1109 unsigned int set, unsigned int clear)
1110{
c9f19e96 1111 struct hvsi_struct *hp = tty->driver_data;
1da177e4
LT
1112 unsigned long flags;
1113 uint16_t new_mctrl;
1114
1115 /* we can only alter DTR */
1116 clear &= TIOCM_DTR;
1117 set &= TIOCM_DTR;
1118
1119 spin_lock_irqsave(&hp->lock, flags);
1120
1121 new_mctrl = (hp->mctrl & ~clear) | set;
1122
1123 if (hp->mctrl != new_mctrl) {
1124 hvsi_set_mctrl(hp, new_mctrl);
1125 hp->mctrl = new_mctrl;
1126 }
1127 spin_unlock_irqrestore(&hp->lock, flags);
1128
1129 return 0;
1130}
1131
1132
b68e31d0 1133static const struct tty_operations hvsi_ops = {
1da177e4
LT
1134 .open = hvsi_open,
1135 .close = hvsi_close,
1136 .write = hvsi_write,
1137 .hangup = hvsi_hangup,
1138 .write_room = hvsi_write_room,
1139 .chars_in_buffer = hvsi_chars_in_buffer,
1140 .throttle = hvsi_throttle,
1141 .unthrottle = hvsi_unthrottle,
1142 .tiocmget = hvsi_tiocmget,
1143 .tiocmset = hvsi_tiocmset,
1144};
1145
1146static int __init hvsi_init(void)
1147{
1148 int i;
1149
1150 hvsi_driver = alloc_tty_driver(hvsi_count);
1151 if (!hvsi_driver)
1152 return -ENOMEM;
1153
1154 hvsi_driver->owner = THIS_MODULE;
1da177e4
LT
1155 hvsi_driver->driver_name = "hvsi";
1156 hvsi_driver->name = "hvsi";
1157 hvsi_driver->major = HVSI_MAJOR;
1158 hvsi_driver->minor_start = HVSI_MINOR;
1159 hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM;
1160 hvsi_driver->init_termios = tty_std_termios;
1161 hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
606d099c
AC
1162 hvsi_driver->init_termios.c_ispeed = 9600;
1163 hvsi_driver->init_termios.c_ospeed = 9600;
1da177e4
LT
1164 hvsi_driver->flags = TTY_DRIVER_REAL_RAW;
1165 tty_set_operations(hvsi_driver, &hvsi_ops);
1166
1167 for (i=0; i < hvsi_count; i++) {
1168 struct hvsi_struct *hp = &hvsi_ports[i];
1169 int ret = 1;
1170
0f2ed4c6 1171 ret = request_irq(hp->virq, hvsi_interrupt, IRQF_DISABLED, "hvsi", hp);
1da177e4
LT
1172 if (ret)
1173 printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n",
1174 hp->virq, ret);
1175 }
1176 hvsi_wait = wait_for_state; /* irqs active now */
1177
1178 if (tty_register_driver(hvsi_driver))
1179 panic("Couldn't register hvsi console driver\n");
1180
8b6a7b2e 1181 printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count);
1da177e4
LT
1182
1183 return 0;
1184}
1185device_initcall(hvsi_init);
1186
1187/***** console (not tty) code: *****/
1188
1189static void hvsi_console_print(struct console *console, const char *buf,
1190 unsigned int count)
1191{
1192 struct hvsi_struct *hp = &hvsi_ports[console->index];
1193 char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__;
1194 unsigned int i = 0, n = 0;
1195 int ret, donecr = 0;
1196
1197 mb();
1198 if (!is_open(hp))
1199 return;
1200
1201 /*
1202 * ugh, we have to translate LF -> CRLF ourselves, in place.
1203 * copied from hvc_console.c:
1204 */
1205 while (count > 0 || i > 0) {
1206 if (count > 0 && i < sizeof(c)) {
1207 if (buf[n] == '\n' && !donecr) {
1208 c[i++] = '\r';
1209 donecr = 1;
1210 } else {
1211 c[i++] = buf[n++];
1212 donecr = 0;
1213 --count;
1214 }
1215 } else {
1216 ret = hvsi_put_chars(hp, c, i);
1217 if (ret < 0)
1218 i = 0;
1219 i -= ret;
1220 }
1221 }
1222}
1223
1224static struct tty_driver *hvsi_console_device(struct console *console,
1225 int *index)
1226{
1227 *index = console->index;
1228 return hvsi_driver;
1229}
1230
1231static int __init hvsi_console_setup(struct console *console, char *options)
1232{
72865650 1233 struct hvsi_struct *hp;
1da177e4
LT
1234 int ret;
1235
1236 if (console->index < 0 || console->index >= hvsi_count)
1237 return -1;
72865650 1238 hp = &hvsi_ports[console->index];
1da177e4
LT
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;
954a46e2 1280 const uint32_t *vtermno, *irq;
1da177e4 1281
01b2726d
SR
1282 vtermno = of_get_property(vty, "reg", NULL);
1283 irq = of_get_property(vty, "interrupts", NULL);
1da177e4
LT
1284 if (!vtermno || !irq)
1285 continue;
1286
1287 if (hvsi_count >= MAX_NR_HVSI_CONSOLES) {
1288 of_node_put(vty);
1289 break;
1290 }
1291
1292 hp = &hvsi_ports[hvsi_count];
c4028958
DH
1293 INIT_DELAYED_WORK(&hp->writer, hvsi_write_worker);
1294 INIT_WORK(&hp->handshaker, hvsi_handshaker);
1da177e4
LT
1295 init_waitqueue_head(&hp->emptyq);
1296 init_waitqueue_head(&hp->stateq);
1297 spin_lock_init(&hp->lock);
1298 hp->index = hvsi_count;
1299 hp->inbuf_end = hp->inbuf;
1300 hp->state = HVSI_CLOSED;
1301 hp->vtermno = *vtermno;
6e99e458 1302 hp->virq = irq_create_mapping(NULL, irq[0]);
1da177e4
LT
1303 if (hp->virq == NO_IRQ) {
1304 printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
bf9d8929 1305 __func__, irq[0]);
1da177e4 1306 continue;
0ebfff14 1307 }
1da177e4
LT
1308
1309 hvsi_count++;
1310 }
1311
1312 if (hvsi_count)
1313 register_console(&hvsi_con_driver);
1314 return 0;
1315}
1316console_initcall(hvsi_console_init);