git.oblomov.eu Git - linux-2.6/blob - drivers/char/hvsi.c

   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);