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/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 { 71 struct delayed_work writer; 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; 78 unsigned int count; 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]; 198 199 if (hp->state > ARRAY_SIZE(state_names)) 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); 248 249 pr_debug("%s: %i chars remain\n", __FUNCTION__, remaining); 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 293static int hvsi_read(struct hvsi_struct *hp, char *buf, int count) 294{ 295 unsigned long got; 296 297 got = hvc_get_chars(hp->vtermno, buf, count); 298 299 return got; 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; 313 /* If userland hasn't done an open(2) yet, hp->tty is NULL. */ 314 if (hp->tty && !(hp->tty->flags & CLOCAL)) 315 *to_hangup = hp->tty; 316 } 317 break; 318 case VSV_CLOSE_PROTOCOL: 319 pr_debug("hvsi%i: service processor came back\n", hp->index); 320 if (hp->state != HVSI_CLOSED) { 321 *to_handshake = hp; 322 } 323 break; 324 default: 325 printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ", 326 hp->index); 327 dump_packet(packet); 328 break; 329 } 330} 331 332static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet) 333{ 334 struct hvsi_query_response *resp = (struct hvsi_query_response *)packet; 335 336 switch (hp->state) { 337 case HVSI_WAIT_FOR_VER_RESPONSE: 338 __set_state(hp, HVSI_WAIT_FOR_VER_QUERY); 339 break; 340 case HVSI_WAIT_FOR_MCTRL_RESPONSE: 341 hp->mctrl = 0; 342 if (resp->u.mctrl_word & HVSI_TSDTR) 343 hp->mctrl |= TIOCM_DTR; 344 if (resp->u.mctrl_word & HVSI_TSCD) 345 hp->mctrl |= TIOCM_CD; 346 __set_state(hp, HVSI_OPEN); 347 break; 348 default: 349 printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index); 350 dump_packet(packet); 351 break; 352 } 353} 354 355/* respond to service processor's version query */ 356static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno) 357{ 358 struct hvsi_query_response packet __ALIGNED__; 359 int wrote; 360 361 packet.type = VS_QUERY_RESPONSE_PACKET_HEADER; 362 packet.len = sizeof(struct hvsi_query_response); 363 packet.seqno = atomic_inc_return(&hp->seqno); 364 packet.verb = VSV_SEND_VERSION_NUMBER; 365 packet.u.version = HVSI_VERSION; 366 packet.query_seqno = query_seqno+1; 367 368 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len); 369 dbg_dump_hex((uint8_t*)&packet, packet.len); 370 371 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); 372 if (wrote != packet.len) { 373 printk(KERN_ERR "hvsi%i: couldn't send query response!\n", 374 hp->index); 375 return -EIO; 376 } 377 378 return 0; 379} 380 381static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet) 382{ 383 struct hvsi_query *query = (struct hvsi_query *)packet; 384 385 switch (hp->state) { 386 case HVSI_WAIT_FOR_VER_QUERY: 387 hvsi_version_respond(hp, query->seqno); 388 __set_state(hp, HVSI_OPEN); 389 break; 390 default: 391 printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index); 392 dump_packet(packet); 393 break; 394 } 395} 396 397static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len) 398{ 399 int i; 400 401 for (i=0; i < len; i++) { 402 char c = buf[i]; 403#ifdef CONFIG_MAGIC_SYSRQ 404 if (c == '\0') { 405 hp->sysrq = 1; 406 continue; 407 } else if (hp->sysrq) { 408 handle_sysrq(c, hp->tty); 409 hp->sysrq = 0; 410 continue; 411 } 412#endif /* CONFIG_MAGIC_SYSRQ */ 413 tty_insert_flip_char(hp->tty, c, 0); 414 } 415} 416 417/* 418 * We could get 252 bytes of data at once here. But the tty layer only 419 * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow 420 * it. Accordingly we won't send more than 128 bytes at a time to the flip 421 * buffer, which will give the tty buffer a chance to throttle us. Should the 422 * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be 423 * revisited. 424 */ 425#define TTY_THRESHOLD_THROTTLE 128 426static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp, 427 const uint8_t *packet) 428{ 429 const struct hvsi_header *header = (const struct hvsi_header *)packet; 430 const uint8_t *data = packet + sizeof(struct hvsi_header); 431 int datalen = header->len - sizeof(struct hvsi_header); 432 int overflow = datalen - TTY_THRESHOLD_THROTTLE; 433 434 pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data); 435 436 if (datalen == 0) 437 return NULL; 438 439 if (overflow > 0) { 440 pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __FUNCTION__); 441 datalen = TTY_THRESHOLD_THROTTLE; 442 } 443 444 hvsi_insert_chars(hp, data, datalen); 445 446 if (overflow > 0) { 447 /* 448 * we still have more data to deliver, so we need to save off the 449 * overflow and send it later 450 */ 451 pr_debug("%s: deferring overflow\n", __FUNCTION__); 452 memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow); 453 hp->n_throttle = overflow; 454 } 455 456 return hp->tty; 457} 458 459/* 460 * Returns true/false indicating data successfully read from hypervisor. 461 * Used both to get packets for tty connections and to advance the state 462 * machine during console handshaking (in which case tty = NULL and we ignore 463 * incoming data). 464 */ 465static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip, 466 struct tty_struct **hangup, struct hvsi_struct **handshake) 467{ 468 uint8_t *packet = hp->inbuf; 469 int chunklen; 470 471 *flip = NULL; 472 *hangup = NULL; 473 *handshake = NULL; 474 475 chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ); 476 if (chunklen == 0) { 477 pr_debug("%s: 0-length read\n", __FUNCTION__); 478 return 0; 479 } 480 481 pr_debug("%s: got %i bytes\n", __FUNCTION__, chunklen); 482 dbg_dump_hex(hp->inbuf_end, chunklen); 483 484 hp->inbuf_end += chunklen; 485 486 /* handle all completed packets */ 487 while ((packet < hp->inbuf_end) && got_packet(hp, packet)) { 488 struct hvsi_header *header = (struct hvsi_header *)packet; 489 490 if (!is_header(packet)) { 491 printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index); 492 /* skip bytes until we find a header or run out of data */ 493 while ((packet < hp->inbuf_end) && (!is_header(packet))) 494 packet++; 495 continue; 496 } 497 498 pr_debug("%s: handling %i-byte packet\n", __FUNCTION__, 499 len_packet(packet)); 500 dbg_dump_packet(packet); 501 502 switch (header->type) { 503 case VS_DATA_PACKET_HEADER: 504 if (!is_open(hp)) 505 break; 506 if (hp->tty == NULL) 507 break; /* no tty buffer to put data in */ 508 *flip = hvsi_recv_data(hp, packet); 509 break; 510 case VS_CONTROL_PACKET_HEADER: 511 hvsi_recv_control(hp, packet, hangup, handshake); 512 break; 513 case VS_QUERY_RESPONSE_PACKET_HEADER: 514 hvsi_recv_response(hp, packet); 515 break; 516 case VS_QUERY_PACKET_HEADER: 517 hvsi_recv_query(hp, packet); 518 break; 519 default: 520 printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n", 521 hp->index, header->type); 522 dump_packet(packet); 523 break; 524 } 525 526 packet += len_packet(packet); 527 528 if (*hangup || *handshake) { 529 pr_debug("%s: hangup or handshake\n", __FUNCTION__); 530 /* 531 * we need to send the hangup now before receiving any more data. 532 * If we get "data, hangup, data", we can't deliver the second 533 * data before the hangup. 534 */ 535 break; 536 } 537 } 538 539 compact_inbuf(hp, packet); 540 541 return 1; 542} 543 544static void hvsi_send_overflow(struct hvsi_struct *hp) 545{ 546 pr_debug("%s: delivering %i bytes overflow\n", __FUNCTION__, 547 hp->n_throttle); 548 549 hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle); 550 hp->n_throttle = 0; 551} 552 553/* 554 * must get all pending data because we only get an irq on empty->non-empty 555 * transition 556 */ 557static irqreturn_t hvsi_interrupt(int irq, void *arg) 558{ 559 struct hvsi_struct *hp = (struct hvsi_struct *)arg; 560 struct tty_struct *flip; 561 struct tty_struct *hangup; 562 struct hvsi_struct *handshake; 563 unsigned long flags; 564 int again = 1; 565 566 pr_debug("%s\n", __FUNCTION__); 567 568 while (again) { 569 spin_lock_irqsave(&hp->lock, flags); 570 again = hvsi_load_chunk(hp, &flip, &hangup, &handshake); 571 spin_unlock_irqrestore(&hp->lock, flags); 572 573 /* 574 * we have to call tty_flip_buffer_push() and tty_hangup() outside our 575 * spinlock. But we also have to keep going until we've read all the 576 * available data. 577 */ 578 579 if (flip) { 580 /* there was data put in the tty flip buffer */ 581 tty_flip_buffer_push(flip); 582 flip = NULL; 583 } 584 585 if (hangup) { 586 tty_hangup(hangup); 587 } 588 589 if (handshake) { 590 pr_debug("hvsi%i: attempting re-handshake\n", handshake->index); 591 schedule_work(&handshake->handshaker); 592 } 593 } 594 595 spin_lock_irqsave(&hp->lock, flags); 596 if (hp->tty && hp->n_throttle 597 && (!test_bit(TTY_THROTTLED, &hp->tty->flags))) { 598 /* we weren't hung up and we weren't throttled, so we can deliver the 599 * rest now */ 600 flip = hp->tty; 601 hvsi_send_overflow(hp); 602 } 603 spin_unlock_irqrestore(&hp->lock, flags); 604 605 if (flip) { 606 tty_flip_buffer_push(flip); 607 } 608 609 return IRQ_HANDLED; 610} 611 612/* for boot console, before the irq handler is running */ 613static int __init poll_for_state(struct hvsi_struct *hp, int state) 614{ 615 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT; 616 617 for (;;) { 618 hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */ 619 620 if (hp->state == state) 621 return 0; 622 623 mdelay(5); 624 if (time_after(jiffies, end_jiffies)) 625 return -EIO; 626 } 627} 628 629/* wait for irq handler to change our state */ 630static int wait_for_state(struct hvsi_struct *hp, int state) 631{ 632 int ret = 0; 633 634 if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT)) 635 ret = -EIO; 636 637 return ret; 638} 639 640static int hvsi_query(struct hvsi_struct *hp, uint16_t verb) 641{ 642 struct hvsi_query packet __ALIGNED__; 643 int wrote; 644 645 packet.type = VS_QUERY_PACKET_HEADER; 646 packet.len = sizeof(struct hvsi_query); 647 packet.seqno = atomic_inc_return(&hp->seqno); 648 packet.verb = verb; 649 650 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len); 651 dbg_dump_hex((uint8_t*)&packet, packet.len); 652 653 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); 654 if (wrote != packet.len) { 655 printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index, 656 wrote); 657 return -EIO; 658 } 659 660 return 0; 661} 662 663static int hvsi_get_mctrl(struct hvsi_struct *hp) 664{ 665 int ret; 666 667 set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE); 668 hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS); 669 670 ret = hvsi_wait(hp, HVSI_OPEN); 671 if (ret < 0) { 672 printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index); 673 set_state(hp, HVSI_OPEN); 674 return ret; 675 } 676 677 pr_debug("%s: mctrl 0x%x\n", __FUNCTION__, hp->mctrl); 678 679 return 0; 680} 681 682/* note that we can only set DTR */ 683static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl) 684{ 685 struct hvsi_control packet __ALIGNED__; 686 int wrote; 687 688 packet.type = VS_CONTROL_PACKET_HEADER, 689 packet.seqno = atomic_inc_return(&hp->seqno); 690 packet.len = sizeof(struct hvsi_control); 691 packet.verb = VSV_SET_MODEM_CTL; 692 packet.mask = HVSI_TSDTR; 693 694 if (mctrl & TIOCM_DTR) 695 packet.word = HVSI_TSDTR; 696 697 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len); 698 dbg_dump_hex((uint8_t*)&packet, packet.len); 699 700 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); 701 if (wrote != packet.len) { 702 printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index); 703 return -EIO; 704 } 705 706 return 0; 707} 708 709static void hvsi_drain_input(struct hvsi_struct *hp) 710{ 711 uint8_t buf[HVSI_MAX_READ] __ALIGNED__; 712 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT; 713 714 while (time_before(end_jiffies, jiffies)) 715 if (0 == hvsi_read(hp, buf, HVSI_MAX_READ)) 716 break; 717} 718 719static int hvsi_handshake(struct hvsi_struct *hp) 720{ 721 int ret; 722 723 /* 724 * We could have a CLOSE or other data waiting for us before we even try 725 * to open; try to throw it all away so we don't get confused. (CLOSE 726 * is the first message sent up the pipe when the FSP comes online. We 727 * need to distinguish between "it came up a while ago and we're the first 728 * user" and "it was just reset before it saw our handshake packet".) 729 */ 730 hvsi_drain_input(hp); 731 732 set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE); 733 ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER); 734 if (ret < 0) { 735 printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index); 736 return ret; 737 } 738 739 ret = hvsi_wait(hp, HVSI_OPEN); 740 if (ret < 0) 741 return ret; 742 743 return 0; 744} 745 746static void hvsi_handshaker(struct work_struct *work) 747{ 748 struct hvsi_struct *hp = 749 container_of(work, struct hvsi_struct, handshaker); 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; 792 793 pr_debug("%s: sending %i bytes\n", __FUNCTION__, packet.len); 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; 805 806 pr_debug("%s\n", __FUNCTION__); 807 808 if (line < 0 || line >= hvsi_count) 809 return -ENODEV; 810 hp = &hvsi_ports[line]; 811 812 tty->driver_data = hp; 813 tty->low_latency = 1; /* avoid throttle/tty_flip_buffer_push race */ 814 815 mb(); 816 if (hp->state == HVSI_FSP_DIED) 817 return -EIO; 818 819 spin_lock_irqsave(&hp->lock, flags); 820 hp->tty = tty; 821 hp->count++; 822 atomic_set(&hp->seqno, 0); 823 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE); 824 spin_unlock_irqrestore(&hp->lock, flags); 825 826 if (is_console(hp)) 827 return 0; /* this has already been handshaked as the console */ 828 829 ret = hvsi_handshake(hp); 830 if (ret < 0) { 831 printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name); 832 return ret; 833 } 834 835 ret = hvsi_get_mctrl(hp); 836 if (ret < 0) { 837 printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name); 838 return ret; 839 } 840 841 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR); 842 if (ret < 0) { 843 printk(KERN_ERR "%s: couldn't set DTR\n", tty->name); 844 return ret; 845 } 846 847 return 0; 848} 849 850/* wait for hvsi_write_worker to empty hp->outbuf */ 851static void hvsi_flush_output(struct hvsi_struct *hp) 852{ 853 wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT); 854 855 /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */ 856 cancel_delayed_work(&hp->writer); 857 flush_scheduled_work(); 858 859 /* 860 * it's also possible that our timeout expired and hvsi_write_worker 861 * didn't manage to push outbuf. poof. 862 */ 863 hp->n_outbuf = 0; 864} 865 866static void hvsi_close(struct tty_struct *tty, struct file *filp) 867{ 868 struct hvsi_struct *hp = tty->driver_data; 869 unsigned long flags; 870 871 pr_debug("%s\n", __FUNCTION__); 872 873 if (tty_hung_up_p(filp)) 874 return; 875 876 spin_lock_irqsave(&hp->lock, flags); 877 878 if (--hp->count == 0) { 879 hp->tty = NULL; 880 hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */ 881 882 /* only close down connection if it is not the console */ 883 if (!is_console(hp)) { 884 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */ 885 __set_state(hp, HVSI_CLOSED); 886 /* 887 * any data delivered to the tty layer after this will be 888 * discarded (except for XON/XOFF) 889 */ 890 tty->closing = 1; 891 892 spin_unlock_irqrestore(&hp->lock, flags); 893 894 /* let any existing irq handlers finish. no more will start. */ 895 synchronize_irq(hp->virq); 896 897 /* hvsi_write_worker will re-schedule until outbuf is empty. */ 898 hvsi_flush_output(hp); 899 900 /* tell FSP to stop sending data */ 901 hvsi_close_protocol(hp); 902 903 /* 904 * drain anything FSP is still in the middle of sending, and let 905 * hvsi_handshake drain the rest on the next open. 906 */ 907 hvsi_drain_input(hp); 908 909 spin_lock_irqsave(&hp->lock, flags); 910 } 911 } else if (hp->count < 0) 912 printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n", 913 hp - hvsi_ports, hp->count); 914 915 spin_unlock_irqrestore(&hp->lock, flags); 916} 917 918static void hvsi_hangup(struct tty_struct *tty) 919{ 920 struct hvsi_struct *hp = tty->driver_data; 921 unsigned long flags; 922 923 pr_debug("%s\n", __FUNCTION__); 924 925 spin_lock_irqsave(&hp->lock, flags); 926 927 hp->count = 0; 928 hp->n_outbuf = 0; 929 hp->tty = NULL; 930 931 spin_unlock_irqrestore(&hp->lock, flags); 932} 933 934/* called with hp->lock held */ 935static void hvsi_push(struct hvsi_struct *hp) 936{ 937 int n; 938 939 if (hp->n_outbuf <= 0) 940 return; 941 942 n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf); 943 if (n > 0) { 944 /* success */ 945 pr_debug("%s: wrote %i chars\n", __FUNCTION__, n); 946 hp->n_outbuf = 0; 947 } else if (n == -EIO) { 948 __set_state(hp, HVSI_FSP_DIED); 949 printk(KERN_ERR "hvsi%i: service processor died\n", hp->index); 950 } 951} 952 953/* hvsi_write_worker will keep rescheduling itself until outbuf is empty */ 954static void hvsi_write_worker(struct work_struct *work) 955{ 956 struct hvsi_struct *hp = 957 container_of(work, struct hvsi_struct, writer.work); 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 tty_wakeup(hp->tty); 992 } 993 994out: 995 spin_unlock_irqrestore(&hp->lock, flags); 996} 997 998static int hvsi_write_room(struct tty_struct *tty) 999{ 1000 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data; 1001 1002 return N_OUTBUF - hp->n_outbuf; 1003} 1004 1005static int hvsi_chars_in_buffer(struct tty_struct *tty) 1006{ 1007 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data; 1008 1009 return hp->n_outbuf; 1010} 1011 1012static int hvsi_write(struct tty_struct *tty, 1013 const unsigned char *buf, int count) 1014{ 1015 struct hvsi_struct *hp = tty->driver_data; 1016 const char *source = buf; 1017 unsigned long flags; 1018 int total = 0; 1019 int origcount = count; 1020 1021 spin_lock_irqsave(&hp->lock, flags); 1022 1023 pr_debug("%s: %i chars in buffer\n", __FUNCTION__, hp->n_outbuf); 1024 1025 if (!is_open(hp)) { 1026 /* we're either closing or not yet open; don't accept data */ 1027 pr_debug("%s: not open\n", __FUNCTION__); 1028 goto out; 1029 } 1030 1031 /* 1032 * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf 1033 * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls 1034 * will see there is no room in outbuf and return. 1035 */ 1036 while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) { 1037 int chunksize = min(count, hvsi_write_room(hp->tty)); 1038 1039 BUG_ON(hp->n_outbuf < 0); 1040 memcpy(hp->outbuf + hp->n_outbuf, source, chunksize); 1041 hp->n_outbuf += chunksize; 1042 1043 total += chunksize; 1044 source += chunksize; 1045 count -= chunksize; 1046 hvsi_push(hp); 1047 } 1048 1049 if (hp->n_outbuf > 0) { 1050 /* 1051 * we weren't able to write it all to the hypervisor. 1052 * schedule another push attempt. 1053 */ 1054 schedule_delayed_work(&hp->writer, 10); 1055 } 1056 1057out: 1058 spin_unlock_irqrestore(&hp->lock, flags); 1059 1060 if (total != origcount) 1061 pr_debug("%s: wanted %i, only wrote %i\n", __FUNCTION__, origcount, 1062 total); 1063 1064 return total; 1065} 1066 1067/* 1068 * I have never seen throttle or unthrottle called, so this little throttle 1069 * buffering scheme may or may not work. 1070 */ 1071static void hvsi_throttle(struct tty_struct *tty) 1072{ 1073 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data; 1074 1075 pr_debug("%s\n", __FUNCTION__); 1076 1077 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); 1078} 1079 1080static void hvsi_unthrottle(struct tty_struct *tty) 1081{ 1082 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data; 1083 unsigned long flags; 1084 int shouldflip = 0; 1085 1086 pr_debug("%s\n", __FUNCTION__); 1087 1088 spin_lock_irqsave(&hp->lock, flags); 1089 if (hp->n_throttle) { 1090 hvsi_send_overflow(hp); 1091 shouldflip = 1; 1092 } 1093 spin_unlock_irqrestore(&hp->lock, flags); 1094 1095 if (shouldflip) 1096 tty_flip_buffer_push(hp->tty); 1097 1098 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE); 1099} 1100 1101static int hvsi_tiocmget(struct tty_struct *tty, struct file *file) 1102{ 1103 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data; 1104 1105 hvsi_get_mctrl(hp); 1106 return hp->mctrl; 1107} 1108 1109static int hvsi_tiocmset(struct tty_struct *tty, struct file *file, 1110 unsigned int set, unsigned int clear) 1111{ 1112 struct hvsi_struct *hp = (struct hvsi_struct *)tty->driver_data; 1113 unsigned long flags; 1114 uint16_t new_mctrl; 1115 1116 /* we can only alter DTR */ 1117 clear &= TIOCM_DTR; 1118 set &= TIOCM_DTR; 1119 1120 spin_lock_irqsave(&hp->lock, flags); 1121 1122 new_mctrl = (hp->mctrl & ~clear) | set; 1123 1124 if (hp->mctrl != new_mctrl) { 1125 hvsi_set_mctrl(hp, new_mctrl); 1126 hp->mctrl = new_mctrl; 1127 } 1128 spin_unlock_irqrestore(&hp->lock, flags); 1129 1130 return 0; 1131} 1132 1133 1134static const struct tty_operations hvsi_ops = { 1135 .open = hvsi_open, 1136 .close = hvsi_close, 1137 .write = hvsi_write, 1138 .hangup = hvsi_hangup, 1139 .write_room = hvsi_write_room, 1140 .chars_in_buffer = hvsi_chars_in_buffer, 1141 .throttle = hvsi_throttle, 1142 .unthrottle = hvsi_unthrottle, 1143 .tiocmget = hvsi_tiocmget, 1144 .tiocmset = hvsi_tiocmset, 1145}; 1146 1147static int __init hvsi_init(void) 1148{ 1149 int i; 1150 1151 hvsi_driver = alloc_tty_driver(hvsi_count); 1152 if (!hvsi_driver) 1153 return -ENOMEM; 1154 1155 hvsi_driver->owner = THIS_MODULE; 1156 hvsi_driver->driver_name = "hvsi"; 1157 hvsi_driver->name = "hvsi"; 1158 hvsi_driver->major = HVSI_MAJOR; 1159 hvsi_driver->minor_start = HVSI_MINOR; 1160 hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM; 1161 hvsi_driver->init_termios = tty_std_termios; 1162 hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL; 1163 hvsi_driver->init_termios.c_ispeed = 9600; 1164 hvsi_driver->init_termios.c_ospeed = 9600; 1165 hvsi_driver->flags = TTY_DRIVER_REAL_RAW; 1166 tty_set_operations(hvsi_driver, &hvsi_ops); 1167 1168 for (i=0; i < hvsi_count; i++) { 1169 struct hvsi_struct *hp = &hvsi_ports[i]; 1170 int ret = 1; 1171 1172 ret = request_irq(hp->virq, hvsi_interrupt, IRQF_DISABLED, "hvsi", hp); 1173 if (ret) 1174 printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n", 1175 hp->virq, ret); 1176 } 1177 hvsi_wait = wait_for_state; /* irqs active now */ 1178 1179 if (tty_register_driver(hvsi_driver)) 1180 panic("Couldn't register hvsi console driver\n"); 1181 1182 printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count); 1183 1184 return 0; 1185} 1186device_initcall(hvsi_init); 1187 1188/***** console (not tty) code: *****/ 1189 1190static void hvsi_console_print(struct console *console, const char *buf, 1191 unsigned int count) 1192{ 1193 struct hvsi_struct *hp = &hvsi_ports[console->index]; 1194 char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__; 1195 unsigned int i = 0, n = 0; 1196 int ret, donecr = 0; 1197 1198 mb(); 1199 if (!is_open(hp)) 1200 return; 1201 1202 /* 1203 * ugh, we have to translate LF -> CRLF ourselves, in place. 1204 * copied from hvc_console.c: 1205 */ 1206 while (count > 0 || i > 0) { 1207 if (count > 0 && i < sizeof(c)) { 1208 if (buf[n] == '\n' && !donecr) { 1209 c[i++] = '\r'; 1210 donecr = 1; 1211 } else { 1212 c[i++] = buf[n++]; 1213 donecr = 0; 1214 --count; 1215 } 1216 } else { 1217 ret = hvsi_put_chars(hp, c, i); 1218 if (ret < 0) 1219 i = 0; 1220 i -= ret; 1221 } 1222 } 1223} 1224 1225static struct tty_driver *hvsi_console_device(struct console *console, 1226 int *index) 1227{ 1228 *index = console->index; 1229 return hvsi_driver; 1230} 1231 1232static int __init hvsi_console_setup(struct console *console, char *options) 1233{ 1234 struct hvsi_struct *hp = &hvsi_ports[console->index]; 1235 int ret; 1236 1237 if (console->index < 0 || console->index >= hvsi_count) 1238 return -1; 1239 1240 /* give the FSP a chance to change the baud rate when we re-open */ 1241 hvsi_close_protocol(hp); 1242 1243 ret = hvsi_handshake(hp); 1244 if (ret < 0) 1245 return ret; 1246 1247 ret = hvsi_get_mctrl(hp); 1248 if (ret < 0) 1249 return ret; 1250 1251 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR); 1252 if (ret < 0) 1253 return ret; 1254 1255 hp->flags |= HVSI_CONSOLE; 1256 1257 return 0; 1258} 1259 1260static struct console hvsi_con_driver = { 1261 .name = "hvsi", 1262 .write = hvsi_console_print, 1263 .device = hvsi_console_device, 1264 .setup = hvsi_console_setup, 1265 .flags = CON_PRINTBUFFER, 1266 .index = -1, 1267}; 1268 1269static int __init hvsi_console_init(void) 1270{ 1271 struct device_node *vty; 1272 1273 hvsi_wait = poll_for_state; /* no irqs yet; must poll */ 1274 1275 /* search device tree for vty nodes */ 1276 for (vty = of_find_compatible_node(NULL, "serial", "hvterm-protocol"); 1277 vty != NULL; 1278 vty = of_find_compatible_node(vty, "serial", "hvterm-protocol")) { 1279 struct hvsi_struct *hp; 1280 const uint32_t *vtermno, *irq; 1281 1282 vtermno = of_get_property(vty, "reg", NULL); 1283 irq = of_get_property(vty, "interrupts", NULL); 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]; 1293 INIT_DELAYED_WORK(&hp->writer, hvsi_write_worker); 1294 INIT_WORK(&hp->handshaker, hvsi_handshaker); 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; 1302 hp->virq = irq_create_mapping(NULL, irq[0]); 1303 if (hp->virq == NO_IRQ) { 1304 printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n", 1305 __FUNCTION__, irq[0]); 1306 continue; 1307 } 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); 1317