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#include <asm/hvsi.h> 53 54#define HVSI_MAJOR 229 55#define HVSI_MINOR 128 56#define MAX_NR_HVSI_CONSOLES 4 57 58#define HVSI_TIMEOUT (5*HZ) 59#define HVSI_VERSION 1 60#define HVSI_MAX_PACKET 256 61#define HVSI_MAX_READ 16 62#define HVSI_MAX_OUTGOING_DATA 12 63#define N_OUTBUF 12 64 65/* 66 * we pass data via two 8-byte registers, so we would like our char arrays 67 * properly aligned for those loads. 68 */ 69#define __ALIGNED__ __attribute__((__aligned__(sizeof(long)))) 70 71struct hvsi_struct { 72 struct tty_port port; 73 struct delayed_work writer; 74 struct work_struct handshaker; 75 wait_queue_head_t emptyq; /* woken when outbuf is emptied */ 76 wait_queue_head_t stateq; /* woken when HVSI state changes */ 77 spinlock_t lock; 78 int index; 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 112static inline int is_console(struct hvsi_struct *hp) 113{ 114 return hp->flags & HVSI_CONSOLE; 115} 116 117static inline int is_open(struct hvsi_struct *hp) 118{ 119 /* if we're waiting for an mctrl then we're already open */ 120 return (hp->state == HVSI_OPEN) 121 || (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE); 122} 123 124static inline void print_state(struct hvsi_struct *hp) 125{ 126#ifdef DEBUG 127 static const char *state_names[] = { 128 "HVSI_CLOSED", 129 "HVSI_WAIT_FOR_VER_RESPONSE", 130 "HVSI_WAIT_FOR_VER_QUERY", 131 "HVSI_OPEN", 132 "HVSI_WAIT_FOR_MCTRL_RESPONSE", 133 "HVSI_FSP_DIED", 134 }; 135 const char *name = (hp->state < ARRAY_SIZE(state_names)) 136 ? state_names[hp->state] : "UNKNOWN"; 137 138 pr_debug("hvsi%i: state = %s\n", hp->index, name); 139#endif /* DEBUG */ 140} 141 142static inline void __set_state(struct hvsi_struct *hp, int state) 143{ 144 hp->state = state; 145 print_state(hp); 146 wake_up_all(&hp->stateq); 147} 148 149static inline void set_state(struct hvsi_struct *hp, int state) 150{ 151 unsigned long flags; 152 153 spin_lock_irqsave(&hp->lock, flags); 154 __set_state(hp, state); 155 spin_unlock_irqrestore(&hp->lock, flags); 156} 157 158static inline int len_packet(const uint8_t *packet) 159{ 160 return (int)((struct hvsi_header *)packet)->len; 161} 162 163static inline int is_header(const uint8_t *packet) 164{ 165 struct hvsi_header *header = (struct hvsi_header *)packet; 166 return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER; 167} 168 169static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet) 170{ 171 if (hp->inbuf_end < packet + sizeof(struct hvsi_header)) 172 return 0; /* don't even have the packet header */ 173 174 if (hp->inbuf_end < (packet + len_packet(packet))) 175 return 0; /* don't have the rest of the packet */ 176 177 return 1; 178} 179 180/* shift remaining bytes in packetbuf down */ 181static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to) 182{ 183 int remaining = (int)(hp->inbuf_end - read_to); 184 185 pr_debug("%s: %i chars remain\n", __func__, remaining); 186 187 if (read_to != hp->inbuf) 188 memmove(hp->inbuf, read_to, remaining); 189 190 hp->inbuf_end = hp->inbuf + remaining; 191} 192 193#ifdef DEBUG 194#define dbg_dump_packet(packet) dump_packet(packet) 195#define dbg_dump_hex(data, len) dump_hex(data, len) 196#else 197#define dbg_dump_packet(packet) do { } while (0) 198#define dbg_dump_hex(data, len) do { } while (0) 199#endif 200 201static void dump_hex(const uint8_t *data, int len) 202{ 203 int i; 204 205 printk(" "); 206 for (i=0; i < len; i++) 207 printk("%.2x", data[i]); 208 209 printk("\n "); 210 for (i=0; i < len; i++) { 211 if (isprint(data[i])) 212 printk("%c", data[i]); 213 else 214 printk("."); 215 } 216 printk("\n"); 217} 218 219static void dump_packet(uint8_t *packet) 220{ 221 struct hvsi_header *header = (struct hvsi_header *)packet; 222 223 printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len, 224 header->seqno); 225 226 dump_hex(packet, header->len); 227} 228 229static int hvsi_read(struct hvsi_struct *hp, char *buf, int count) 230{ 231 unsigned long got; 232 233 got = hvc_get_chars(hp->vtermno, buf, count); 234 235 return got; 236} 237 238static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet, 239 struct tty_struct *tty, struct hvsi_struct **to_handshake) 240{ 241 struct hvsi_control *header = (struct hvsi_control *)packet; 242 243 switch (be16_to_cpu(header->verb)) { 244 case VSV_MODEM_CTL_UPDATE: 245 if ((be32_to_cpu(header->word) & HVSI_TSCD) == 0) { 246 /* CD went away; no more connection */ 247 pr_debug("hvsi%i: CD dropped\n", hp->index); 248 hp->mctrl &= TIOCM_CD; 249 if (tty && !C_CLOCAL(tty)) 250 tty_hangup(tty); 251 } 252 break; 253 case VSV_CLOSE_PROTOCOL: 254 pr_debug("hvsi%i: service processor came back\n", hp->index); 255 if (hp->state != HVSI_CLOSED) { 256 *to_handshake = hp; 257 } 258 break; 259 default: 260 printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ", 261 hp->index); 262 dump_packet(packet); 263 break; 264 } 265} 266 267static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet) 268{ 269 struct hvsi_query_response *resp = (struct hvsi_query_response *)packet; 270 uint32_t mctrl_word; 271 272 switch (hp->state) { 273 case HVSI_WAIT_FOR_VER_RESPONSE: 274 __set_state(hp, HVSI_WAIT_FOR_VER_QUERY); 275 break; 276 case HVSI_WAIT_FOR_MCTRL_RESPONSE: 277 hp->mctrl = 0; 278 mctrl_word = be32_to_cpu(resp->u.mctrl_word); 279 if (mctrl_word & HVSI_TSDTR) 280 hp->mctrl |= TIOCM_DTR; 281 if (mctrl_word & HVSI_TSCD) 282 hp->mctrl |= TIOCM_CD; 283 __set_state(hp, HVSI_OPEN); 284 break; 285 default: 286 printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index); 287 dump_packet(packet); 288 break; 289 } 290} 291 292/* respond to service processor's version query */ 293static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno) 294{ 295 struct hvsi_query_response packet __ALIGNED__; 296 int wrote; 297 298 packet.hdr.type = VS_QUERY_RESPONSE_PACKET_HEADER; 299 packet.hdr.len = sizeof(struct hvsi_query_response); 300 packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno)); 301 packet.verb = cpu_to_be16(VSV_SEND_VERSION_NUMBER); 302 packet.u.version = HVSI_VERSION; 303 packet.query_seqno = cpu_to_be16(query_seqno+1); 304 305 pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len); 306 dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); 307 308 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); 309 if (wrote != packet.hdr.len) { 310 printk(KERN_ERR "hvsi%i: couldn't send query response!\n", 311 hp->index); 312 return -EIO; 313 } 314 315 return 0; 316} 317 318static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet) 319{ 320 struct hvsi_query *query = (struct hvsi_query *)packet; 321 322 switch (hp->state) { 323 case HVSI_WAIT_FOR_VER_QUERY: 324 hvsi_version_respond(hp, be16_to_cpu(query->hdr.seqno)); 325 __set_state(hp, HVSI_OPEN); 326 break; 327 default: 328 printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index); 329 dump_packet(packet); 330 break; 331 } 332} 333 334static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len) 335{ 336 int i; 337 338 for (i=0; i < len; i++) { 339 char c = buf[i]; 340#ifdef CONFIG_MAGIC_SYSRQ 341 if (c == '\0') { 342 hp->sysrq = 1; 343 continue; 344 } else if (hp->sysrq) { 345 handle_sysrq(c); 346 hp->sysrq = 0; 347 continue; 348 } 349#endif /* CONFIG_MAGIC_SYSRQ */ 350 tty_insert_flip_char(&hp->port, c, 0); 351 } 352} 353 354/* 355 * We could get 252 bytes of data at once here. But the tty layer only 356 * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow 357 * it. Accordingly we won't send more than 128 bytes at a time to the flip 358 * buffer, which will give the tty buffer a chance to throttle us. Should the 359 * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be 360 * revisited. 361 */ 362#define TTY_THRESHOLD_THROTTLE 128 363static bool hvsi_recv_data(struct hvsi_struct *hp, const uint8_t *packet) 364{ 365 const struct hvsi_header *header = (const struct hvsi_header *)packet; 366 const uint8_t *data = packet + sizeof(struct hvsi_header); 367 int datalen = header->len - sizeof(struct hvsi_header); 368 int overflow = datalen - TTY_THRESHOLD_THROTTLE; 369 370 pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data); 371 372 if (datalen == 0) 373 return false; 374 375 if (overflow > 0) { 376 pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__); 377 datalen = TTY_THRESHOLD_THROTTLE; 378 } 379 380 hvsi_insert_chars(hp, data, datalen); 381 382 if (overflow > 0) { 383 /* 384 * we still have more data to deliver, so we need to save off the 385 * overflow and send it later 386 */ 387 pr_debug("%s: deferring overflow\n", __func__); 388 memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow); 389 hp->n_throttle = overflow; 390 } 391 392 return true; 393} 394 395/* 396 * Returns true/false indicating data successfully read from hypervisor. 397 * Used both to get packets for tty connections and to advance the state 398 * machine during console handshaking (in which case tty = NULL and we ignore 399 * incoming data). 400 */ 401static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct *tty, 402 struct hvsi_struct **handshake) 403{ 404 uint8_t *packet = hp->inbuf; 405 int chunklen; 406 bool flip = false; 407 408 *handshake = NULL; 409 410 chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ); 411 if (chunklen == 0) { 412 pr_debug("%s: 0-length read\n", __func__); 413 return 0; 414 } 415 416 pr_debug("%s: got %i bytes\n", __func__, chunklen); 417 dbg_dump_hex(hp->inbuf_end, chunklen); 418 419 hp->inbuf_end += chunklen; 420 421 /* handle all completed packets */ 422 while ((packet < hp->inbuf_end) && got_packet(hp, packet)) { 423 struct hvsi_header *header = (struct hvsi_header *)packet; 424 425 if (!is_header(packet)) { 426 printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index); 427 /* skip bytes until we find a header or run out of data */ 428 while ((packet < hp->inbuf_end) && (!is_header(packet))) 429 packet++; 430 continue; 431 } 432 433 pr_debug("%s: handling %i-byte packet\n", __func__, 434 len_packet(packet)); 435 dbg_dump_packet(packet); 436 437 switch (header->type) { 438 case VS_DATA_PACKET_HEADER: 439 if (!is_open(hp)) 440 break; 441 flip = hvsi_recv_data(hp, packet); 442 break; 443 case VS_CONTROL_PACKET_HEADER: 444 hvsi_recv_control(hp, packet, tty, handshake); 445 break; 446 case VS_QUERY_RESPONSE_PACKET_HEADER: 447 hvsi_recv_response(hp, packet); 448 break; 449 case VS_QUERY_PACKET_HEADER: 450 hvsi_recv_query(hp, packet); 451 break; 452 default: 453 printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n", 454 hp->index, header->type); 455 dump_packet(packet); 456 break; 457 } 458 459 packet += len_packet(packet); 460 461 if (*handshake) { 462 pr_debug("%s: handshake\n", __func__); 463 break; 464 } 465 } 466 467 compact_inbuf(hp, packet); 468 469 if (flip) 470 tty_flip_buffer_push(&hp->port); 471 472 return 1; 473} 474 475static void hvsi_send_overflow(struct hvsi_struct *hp) 476{ 477 pr_debug("%s: delivering %i bytes overflow\n", __func__, 478 hp->n_throttle); 479 480 hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle); 481 hp->n_throttle = 0; 482} 483 484/* 485 * must get all pending data because we only get an irq on empty->non-empty 486 * transition 487 */ 488static irqreturn_t hvsi_interrupt(int irq, void *arg) 489{ 490 struct hvsi_struct *hp = (struct hvsi_struct *)arg; 491 struct hvsi_struct *handshake; 492 struct tty_struct *tty; 493 unsigned long flags; 494 int again = 1; 495 496 pr_debug("%s\n", __func__); 497 498 tty = tty_port_tty_get(&hp->port); 499 500 while (again) { 501 spin_lock_irqsave(&hp->lock, flags); 502 again = hvsi_load_chunk(hp, tty, &handshake); 503 spin_unlock_irqrestore(&hp->lock, flags); 504 505 if (handshake) { 506 pr_debug("hvsi%i: attempting re-handshake\n", handshake->index); 507 schedule_work(&handshake->handshaker); 508 } 509 } 510 511 spin_lock_irqsave(&hp->lock, flags); 512 if (tty && hp->n_throttle && !test_bit(TTY_THROTTLED, &tty->flags)) { 513 /* we weren't hung up and we weren't throttled, so we can 514 * deliver the rest now */ 515 hvsi_send_overflow(hp); 516 tty_flip_buffer_push(&hp->port); 517 } 518 spin_unlock_irqrestore(&hp->lock, flags); 519 520 tty_kref_put(tty); 521 522 return IRQ_HANDLED; 523} 524 525/* for boot console, before the irq handler is running */ 526static int __init poll_for_state(struct hvsi_struct *hp, int state) 527{ 528 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT; 529 530 for (;;) { 531 hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */ 532 533 if (hp->state == state) 534 return 0; 535 536 mdelay(5); 537 if (time_after(jiffies, end_jiffies)) 538 return -EIO; 539 } 540} 541 542/* wait for irq handler to change our state */ 543static int wait_for_state(struct hvsi_struct *hp, int state) 544{ 545 int ret = 0; 546 547 if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT)) 548 ret = -EIO; 549 550 return ret; 551} 552 553static int hvsi_query(struct hvsi_struct *hp, uint16_t verb) 554{ 555 struct hvsi_query packet __ALIGNED__; 556 int wrote; 557 558 packet.hdr.type = VS_QUERY_PACKET_HEADER; 559 packet.hdr.len = sizeof(struct hvsi_query); 560 packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno)); 561 packet.verb = cpu_to_be16(verb); 562 563 pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len); 564 dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); 565 566 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); 567 if (wrote != packet.hdr.len) { 568 printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index, 569 wrote); 570 return -EIO; 571 } 572 573 return 0; 574} 575 576static int hvsi_get_mctrl(struct hvsi_struct *hp) 577{ 578 int ret; 579 580 set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE); 581 hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS); 582 583 ret = hvsi_wait(hp, HVSI_OPEN); 584 if (ret < 0) { 585 printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index); 586 set_state(hp, HVSI_OPEN); 587 return ret; 588 } 589 590 pr_debug("%s: mctrl 0x%x\n", __func__, hp->mctrl); 591 592 return 0; 593} 594 595/* note that we can only set DTR */ 596static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl) 597{ 598 struct hvsi_control packet __ALIGNED__; 599 int wrote; 600 601 packet.hdr.type = VS_CONTROL_PACKET_HEADER; 602 packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno)); 603 packet.hdr.len = sizeof(struct hvsi_control); 604 packet.verb = cpu_to_be16(VSV_SET_MODEM_CTL); 605 packet.mask = cpu_to_be32(HVSI_TSDTR); 606 607 if (mctrl & TIOCM_DTR) 608 packet.word = cpu_to_be32(HVSI_TSDTR); 609 610 pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len); 611 dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); 612 613 wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); 614 if (wrote != packet.hdr.len) { 615 printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index); 616 return -EIO; 617 } 618 619 return 0; 620} 621 622static void hvsi_drain_input(struct hvsi_struct *hp) 623{ 624 uint8_t buf[HVSI_MAX_READ] __ALIGNED__; 625 unsigned long end_jiffies = jiffies + HVSI_TIMEOUT; 626 627 while (time_before(end_jiffies, jiffies)) 628 if (0 == hvsi_read(hp, buf, HVSI_MAX_READ)) 629 break; 630} 631 632static int hvsi_handshake(struct hvsi_struct *hp) 633{ 634 int ret; 635 636 /* 637 * We could have a CLOSE or other data waiting for us before we even try 638 * to open; try to throw it all away so we don't get confused. (CLOSE 639 * is the first message sent up the pipe when the FSP comes online. We 640 * need to distinguish between "it came up a while ago and we're the first 641 * user" and "it was just reset before it saw our handshake packet".) 642 */ 643 hvsi_drain_input(hp); 644 645 set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE); 646 ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER); 647 if (ret < 0) { 648 printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index); 649 return ret; 650 } 651 652 ret = hvsi_wait(hp, HVSI_OPEN); 653 if (ret < 0) 654 return ret; 655 656 return 0; 657} 658 659static void hvsi_handshaker(struct work_struct *work) 660{ 661 struct hvsi_struct *hp = 662 container_of(work, struct hvsi_struct, handshaker); 663 664 if (hvsi_handshake(hp) >= 0) 665 return; 666 667 printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index); 668 if (is_console(hp)) { 669 /* 670 * ttys will re-attempt the handshake via hvsi_open, but 671 * the console will not. 672 */ 673 printk(KERN_ERR "hvsi%i: lost console!\n", hp->index); 674 } 675} 676 677static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count) 678{ 679 struct hvsi_data packet __ALIGNED__; 680 int ret; 681 682 BUG_ON(count > HVSI_MAX_OUTGOING_DATA); 683 684 packet.hdr.type = VS_DATA_PACKET_HEADER; 685 packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno)); 686 packet.hdr.len = count + sizeof(struct hvsi_header); 687 memcpy(&packet.data, buf, count); 688 689 ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); 690 if (ret == packet.hdr.len) { 691 /* return the number of chars written, not the packet length */ 692 return count; 693 } 694 return ret; /* return any errors */ 695} 696 697static void hvsi_close_protocol(struct hvsi_struct *hp) 698{ 699 struct hvsi_control packet __ALIGNED__; 700 701 packet.hdr.type = VS_CONTROL_PACKET_HEADER; 702 packet.hdr.seqno = cpu_to_be16(atomic_inc_return(&hp->seqno)); 703 packet.hdr.len = 6; 704 packet.verb = cpu_to_be16(VSV_CLOSE_PROTOCOL); 705 706 pr_debug("%s: sending %i bytes\n", __func__, packet.hdr.len); 707 dbg_dump_hex((uint8_t*)&packet, packet.hdr.len); 708 709 hvc_put_chars(hp->vtermno, (char *)&packet, packet.hdr.len); 710} 711 712static int hvsi_open(struct tty_struct *tty, struct file *filp) 713{ 714 struct hvsi_struct *hp; 715 unsigned long flags; 716 int ret; 717 718 pr_debug("%s\n", __func__); 719 720 hp = &hvsi_ports[tty->index]; 721 722 tty->driver_data = hp; 723 724 mb(); 725 if (hp->state == HVSI_FSP_DIED) 726 return -EIO; 727 728 tty_port_tty_set(&hp->port, tty); 729 spin_lock_irqsave(&hp->lock, flags); 730 hp->port.count++; 731 atomic_set(&hp->seqno, 0); 732 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE); 733 spin_unlock_irqrestore(&hp->lock, flags); 734 735 if (is_console(hp)) 736 return 0; /* this has already been handshaked as the console */ 737 738 ret = hvsi_handshake(hp); 739 if (ret < 0) { 740 printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name); 741 return ret; 742 } 743 744 ret = hvsi_get_mctrl(hp); 745 if (ret < 0) { 746 printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name); 747 return ret; 748 } 749 750 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR); 751 if (ret < 0) { 752 printk(KERN_ERR "%s: couldn't set DTR\n", tty->name); 753 return ret; 754 } 755 756 return 0; 757} 758 759/* wait for hvsi_write_worker to empty hp->outbuf */ 760static void hvsi_flush_output(struct hvsi_struct *hp) 761{ 762 wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT); 763 764 /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */ 765 cancel_delayed_work_sync(&hp->writer); 766 flush_work(&hp->handshaker); 767 768 /* 769 * it's also possible that our timeout expired and hvsi_write_worker 770 * didn't manage to push outbuf. poof. 771 */ 772 hp->n_outbuf = 0; 773} 774 775static void hvsi_close(struct tty_struct *tty, struct file *filp) 776{ 777 struct hvsi_struct *hp = tty->driver_data; 778 unsigned long flags; 779 780 pr_debug("%s\n", __func__); 781 782 if (tty_hung_up_p(filp)) 783 return; 784 785 spin_lock_irqsave(&hp->lock, flags); 786 787 if (--hp->port.count == 0) { 788 tty_port_tty_set(&hp->port, NULL); 789 hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */ 790 791 /* only close down connection if it is not the console */ 792 if (!is_console(hp)) { 793 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */ 794 __set_state(hp, HVSI_CLOSED); 795 /* 796 * any data delivered to the tty layer after this will be 797 * discarded (except for XON/XOFF) 798 */ 799 tty->closing = 1; 800 801 spin_unlock_irqrestore(&hp->lock, flags); 802 803 /* let any existing irq handlers finish. no more will start. */ 804 synchronize_irq(hp->virq); 805 806 /* hvsi_write_worker will re-schedule until outbuf is empty. */ 807 hvsi_flush_output(hp); 808 809 /* tell FSP to stop sending data */ 810 hvsi_close_protocol(hp); 811 812 /* 813 * drain anything FSP is still in the middle of sending, and let 814 * hvsi_handshake drain the rest on the next open. 815 */ 816 hvsi_drain_input(hp); 817 818 spin_lock_irqsave(&hp->lock, flags); 819 } 820 } else if (hp->port.count < 0) 821 printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n", 822 hp - hvsi_ports, hp->port.count); 823 824 spin_unlock_irqrestore(&hp->lock, flags); 825} 826 827static void hvsi_hangup(struct tty_struct *tty) 828{ 829 struct hvsi_struct *hp = tty->driver_data; 830 unsigned long flags; 831 832 pr_debug("%s\n", __func__); 833 834 tty_port_tty_set(&hp->port, NULL); 835 836 spin_lock_irqsave(&hp->lock, flags); 837 hp->port.count = 0; 838 hp->n_outbuf = 0; 839 spin_unlock_irqrestore(&hp->lock, flags); 840} 841 842/* called with hp->lock held */ 843static void hvsi_push(struct hvsi_struct *hp) 844{ 845 int n; 846 847 if (hp->n_outbuf <= 0) 848 return; 849 850 n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf); 851 if (n > 0) { 852 /* success */ 853 pr_debug("%s: wrote %i chars\n", __func__, n); 854 hp->n_outbuf = 0; 855 } else if (n == -EIO) { 856 __set_state(hp, HVSI_FSP_DIED); 857 printk(KERN_ERR "hvsi%i: service processor died\n", hp->index); 858 } 859} 860 861/* hvsi_write_worker will keep rescheduling itself until outbuf is empty */ 862static void hvsi_write_worker(struct work_struct *work) 863{ 864 struct hvsi_struct *hp = 865 container_of(work, struct hvsi_struct, writer.work); 866 unsigned long flags; 867#ifdef DEBUG 868 static long start_j = 0; 869 870 if (start_j == 0) 871 start_j = jiffies; 872#endif /* DEBUG */ 873 874 spin_lock_irqsave(&hp->lock, flags); 875 876 pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf); 877 878 if (!is_open(hp)) { 879 /* 880 * We could have a non-open connection if the service processor died 881 * while we were busily scheduling ourselves. In that case, it could 882 * be minutes before the service processor comes back, so only try 883 * again once a second. 884 */ 885 schedule_delayed_work(&hp->writer, HZ); 886 goto out; 887 } 888 889 hvsi_push(hp); 890 if (hp->n_outbuf > 0) 891 schedule_delayed_work(&hp->writer, 10); 892 else { 893#ifdef DEBUG 894 pr_debug("%s: outbuf emptied after %li jiffies\n", __func__, 895 jiffies - start_j); 896 start_j = 0; 897#endif /* DEBUG */ 898 wake_up_all(&hp->emptyq); 899 tty_port_tty_wakeup(&hp->port); 900 } 901 902out: 903 spin_unlock_irqrestore(&hp->lock, flags); 904} 905 906static int hvsi_write_room(struct tty_struct *tty) 907{ 908 struct hvsi_struct *hp = tty->driver_data; 909 910 return N_OUTBUF - hp->n_outbuf; 911} 912 913static int hvsi_chars_in_buffer(struct tty_struct *tty) 914{ 915 struct hvsi_struct *hp = tty->driver_data; 916 917 return hp->n_outbuf; 918} 919 920static int hvsi_write(struct tty_struct *tty, 921 const unsigned char *buf, int count) 922{ 923 struct hvsi_struct *hp = tty->driver_data; 924 const char *source = buf; 925 unsigned long flags; 926 int total = 0; 927 int origcount = count; 928 929 spin_lock_irqsave(&hp->lock, flags); 930 931 pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf); 932 933 if (!is_open(hp)) { 934 /* we're either closing or not yet open; don't accept data */ 935 pr_debug("%s: not open\n", __func__); 936 goto out; 937 } 938 939 /* 940 * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf 941 * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls 942 * will see there is no room in outbuf and return. 943 */ 944 while ((count > 0) && (hvsi_write_room(tty) > 0)) { 945 int chunksize = min(count, hvsi_write_room(tty)); 946 947 BUG_ON(hp->n_outbuf < 0); 948 memcpy(hp->outbuf + hp->n_outbuf, source, chunksize); 949 hp->n_outbuf += chunksize; 950 951 total += chunksize; 952 source += chunksize; 953 count -= chunksize; 954 hvsi_push(hp); 955 } 956 957 if (hp->n_outbuf > 0) { 958 /* 959 * we weren't able to write it all to the hypervisor. 960 * schedule another push attempt. 961 */ 962 schedule_delayed_work(&hp->writer, 10); 963 } 964 965out: 966 spin_unlock_irqrestore(&hp->lock, flags); 967 968 if (total != origcount) 969 pr_debug("%s: wanted %i, only wrote %i\n", __func__, origcount, 970 total); 971 972 return total; 973} 974 975/* 976 * I have never seen throttle or unthrottle called, so this little throttle 977 * buffering scheme may or may not work. 978 */ 979static void hvsi_throttle(struct tty_struct *tty) 980{ 981 struct hvsi_struct *hp = tty->driver_data; 982 983 pr_debug("%s\n", __func__); 984 985 h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); 986} 987 988static void hvsi_unthrottle(struct tty_struct *tty) 989{ 990 struct hvsi_struct *hp = tty->driver_data; 991 unsigned long flags; 992 993 pr_debug("%s\n", __func__); 994 995 spin_lock_irqsave(&hp->lock, flags); 996 if (hp->n_throttle) { 997 hvsi_send_overflow(hp); 998 tty_flip_buffer_push(&hp->port); 999 } 1000 spin_unlock_irqrestore(&hp->lock, flags); 1001 1002 1003 h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE); 1004} 1005 1006static int hvsi_tiocmget(struct tty_struct *tty) 1007{ 1008 struct hvsi_struct *hp = tty->driver_data; 1009 1010 hvsi_get_mctrl(hp); 1011 return hp->mctrl; 1012} 1013 1014static int hvsi_tiocmset(struct tty_struct *tty, 1015 unsigned int set, unsigned int clear) 1016{ 1017 struct hvsi_struct *hp = tty->driver_data; 1018 unsigned long flags; 1019 uint16_t new_mctrl; 1020 1021 /* we can only alter DTR */ 1022 clear &= TIOCM_DTR; 1023 set &= TIOCM_DTR; 1024 1025 spin_lock_irqsave(&hp->lock, flags); 1026 1027 new_mctrl = (hp->mctrl & ~clear) | set; 1028 1029 if (hp->mctrl != new_mctrl) { 1030 hvsi_set_mctrl(hp, new_mctrl); 1031 hp->mctrl = new_mctrl; 1032 } 1033 spin_unlock_irqrestore(&hp->lock, flags); 1034 1035 return 0; 1036} 1037 1038 1039static const struct tty_operations hvsi_ops = { 1040 .open = hvsi_open, 1041 .close = hvsi_close, 1042 .write = hvsi_write, 1043 .hangup = hvsi_hangup, 1044 .write_room = hvsi_write_room, 1045 .chars_in_buffer = hvsi_chars_in_buffer, 1046 .throttle = hvsi_throttle, 1047 .unthrottle = hvsi_unthrottle, 1048 .tiocmget = hvsi_tiocmget, 1049 .tiocmset = hvsi_tiocmset, 1050}; 1051 1052static int __init hvsi_init(void) 1053{ 1054 int i; 1055 1056 hvsi_driver = alloc_tty_driver(hvsi_count); 1057 if (!hvsi_driver) 1058 return -ENOMEM; 1059 1060 hvsi_driver->driver_name = "hvsi"; 1061 hvsi_driver->name = "hvsi"; 1062 hvsi_driver->major = HVSI_MAJOR; 1063 hvsi_driver->minor_start = HVSI_MINOR; 1064 hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM; 1065 hvsi_driver->init_termios = tty_std_termios; 1066 hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL; 1067 hvsi_driver->init_termios.c_ispeed = 9600; 1068 hvsi_driver->init_termios.c_ospeed = 9600; 1069 hvsi_driver->flags = TTY_DRIVER_REAL_RAW; 1070 tty_set_operations(hvsi_driver, &hvsi_ops); 1071 1072 for (i=0; i < hvsi_count; i++) { 1073 struct hvsi_struct *hp = &hvsi_ports[i]; 1074 int ret = 1; 1075 1076 tty_port_link_device(&hp->port, hvsi_driver, i); 1077 1078 ret = request_irq(hp->virq, hvsi_interrupt, 0, "hvsi", hp); 1079 if (ret) 1080 printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n", 1081 hp->virq, ret); 1082 } 1083 hvsi_wait = wait_for_state; /* irqs active now */ 1084 1085 if (tty_register_driver(hvsi_driver)) 1086 panic("Couldn't register hvsi console driver\n"); 1087 1088 printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count); 1089 1090 return 0; 1091} 1092device_initcall(hvsi_init); 1093 1094/***** console (not tty) code: *****/ 1095 1096static void hvsi_console_print(struct console *console, const char *buf, 1097 unsigned int count) 1098{ 1099 struct hvsi_struct *hp = &hvsi_ports[console->index]; 1100 char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__; 1101 unsigned int i = 0, n = 0; 1102 int ret, donecr = 0; 1103 1104 mb(); 1105 if (!is_open(hp)) 1106 return; 1107 1108 /* 1109 * ugh, we have to translate LF -> CRLF ourselves, in place. 1110 * copied from hvc_console.c: 1111 */ 1112 while (count > 0 || i > 0) { 1113 if (count > 0 && i < sizeof(c)) { 1114 if (buf[n] == '\n' && !donecr) { 1115 c[i++] = '\r'; 1116 donecr = 1; 1117 } else { 1118 c[i++] = buf[n++]; 1119 donecr = 0; 1120 --count; 1121 } 1122 } else { 1123 ret = hvsi_put_chars(hp, c, i); 1124 if (ret < 0) 1125 i = 0; 1126 i -= ret; 1127 } 1128 } 1129} 1130 1131static struct tty_driver *hvsi_console_device(struct console *console, 1132 int *index) 1133{ 1134 *index = console->index; 1135 return hvsi_driver; 1136} 1137 1138static int __init hvsi_console_setup(struct console *console, char *options) 1139{ 1140 struct hvsi_struct *hp; 1141 int ret; 1142 1143 if (console->index < 0 || console->index >= hvsi_count) 1144 return -1; 1145 hp = &hvsi_ports[console->index]; 1146 1147 /* give the FSP a chance to change the baud rate when we re-open */ 1148 hvsi_close_protocol(hp); 1149 1150 ret = hvsi_handshake(hp); 1151 if (ret < 0) 1152 return ret; 1153 1154 ret = hvsi_get_mctrl(hp); 1155 if (ret < 0) 1156 return ret; 1157 1158 ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR); 1159 if (ret < 0) 1160 return ret; 1161 1162 hp->flags |= HVSI_CONSOLE; 1163 1164 return 0; 1165} 1166 1167static struct console hvsi_console = { 1168 .name = "hvsi", 1169 .write = hvsi_console_print, 1170 .device = hvsi_console_device, 1171 .setup = hvsi_console_setup, 1172 .flags = CON_PRINTBUFFER, 1173 .index = -1, 1174}; 1175 1176static int __init hvsi_console_init(void) 1177{ 1178 struct device_node *vty; 1179 1180 hvsi_wait = poll_for_state; /* no irqs yet; must poll */ 1181 1182 /* search device tree for vty nodes */ 1183 for_each_compatible_node(vty, "serial", "hvterm-protocol") { 1184 struct hvsi_struct *hp; 1185 const __be32 *vtermno, *irq; 1186 1187 vtermno = of_get_property(vty, "reg", NULL); 1188 irq = of_get_property(vty, "interrupts", NULL); 1189 if (!vtermno || !irq) 1190 continue; 1191 1192 if (hvsi_count >= MAX_NR_HVSI_CONSOLES) { 1193 of_node_put(vty); 1194 break; 1195 } 1196 1197 hp = &hvsi_ports[hvsi_count]; 1198 INIT_DELAYED_WORK(&hp->writer, hvsi_write_worker); 1199 INIT_WORK(&hp->handshaker, hvsi_handshaker); 1200 init_waitqueue_head(&hp->emptyq); 1201 init_waitqueue_head(&hp->stateq); 1202 spin_lock_init(&hp->lock); 1203 tty_port_init(&hp->port); 1204 hp->index = hvsi_count; 1205 hp->inbuf_end = hp->inbuf; 1206 hp->state = HVSI_CLOSED; 1207 hp->vtermno = be32_to_cpup(vtermno); 1208 hp->virq = irq_create_mapping(NULL, be32_to_cpup(irq)); 1209 if (hp->virq == 0) { 1210 printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n", 1211 __func__, be32_to_cpup(irq)); 1212 tty_port_destroy(&hp->port); 1213 continue; 1214 } 1215 1216 hvsi_count++; 1217 } 1218 1219 if (hvsi_count) 1220 register_console(&hvsi_console); 1221 return 0; 1222} 1223console_initcall(hvsi_console_init); 1224