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