1/* 2 * PCBIT-D low-layer interface 3 * 4 * Copyright (C) 1996 Universidade de Lisboa 5 * 6 * Written by Pedro Roque Marques (roque@di.fc.ul.pt) 7 * 8 * This software may be used and distributed according to the terms of 9 * the GNU General Public License, incorporated herein by reference. 10 */ 11 12/* 13 * 19991203 - Fernando Carvalho - takion@superbofh.org 14 * Hacked to compile with egcs and run with current version of isdn modules 15*/ 16 17/* 18 * Based on documentation provided by Inesc: 19 * - "Interface com bus do PC para o PCBIT e PCBIT-D", Inesc, Jan 93 20 */ 21 22/* 23 * TODO: better handling of errors 24 * re-write/remove debug printks 25 */ 26 27#include <linux/string.h> 28#include <linux/kernel.h> 29#include <linux/types.h> 30#include <linux/sched.h> 31#include <linux/slab.h> 32#include <linux/interrupt.h> 33#include <linux/workqueue.h> 34#include <linux/mm.h> 35#include <linux/skbuff.h> 36 37#include <linux/isdnif.h> 38 39#include <asm/system.h> 40#include <asm/io.h> 41 42 43#include "pcbit.h" 44#include "layer2.h" 45#include "edss1.h" 46 47#undef DEBUG_FRAG 48 49 50/* 51 * Prototypes 52 */ 53 54static void pcbit_transmit(struct pcbit_dev *dev); 55 56static void pcbit_recv_ack(struct pcbit_dev *dev, unsigned char ack); 57 58static void pcbit_l2_error(struct pcbit_dev *dev); 59static void pcbit_l2_active_conf(struct pcbit_dev *dev, u_char info); 60static void pcbit_l2_err_recover(unsigned long data); 61 62static void pcbit_firmware_bug(struct pcbit_dev *dev); 63 64static __inline__ void 65pcbit_sched_delivery(struct pcbit_dev *dev) 66{ 67 schedule_work(&dev->qdelivery); 68} 69 70 71/* 72 * Called from layer3 73 */ 74 75int 76pcbit_l2_write(struct pcbit_dev *dev, ulong msg, ushort refnum, 77 struct sk_buff *skb, unsigned short hdr_len) 78{ 79 struct frame_buf *frame, 80 *ptr; 81 unsigned long flags; 82 83 if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) { 84 dev_kfree_skb(skb); 85 return -1; 86 } 87 if ((frame = kmalloc(sizeof(struct frame_buf), 88 GFP_ATOMIC)) == NULL) { 89 printk(KERN_WARNING "pcbit_2_write: kmalloc failed\n"); 90 dev_kfree_skb(skb); 91 return -1; 92 } 93 frame->msg = msg; 94 frame->refnum = refnum; 95 frame->copied = 0; 96 frame->hdr_len = hdr_len; 97 98 if (skb) 99 frame->dt_len = skb->len - hdr_len; 100 else 101 frame->dt_len = 0; 102 103 frame->skb = skb; 104 105 frame->next = NULL; 106 107 spin_lock_irqsave(&dev->lock, flags); 108 109 if (dev->write_queue == NULL) { 110 dev->write_queue = frame; 111 spin_unlock_irqrestore(&dev->lock, flags); 112 pcbit_transmit(dev); 113 } else { 114 for (ptr = dev->write_queue; ptr->next; ptr = ptr->next); 115 ptr->next = frame; 116 117 spin_unlock_irqrestore(&dev->lock, flags); 118 } 119 return 0; 120} 121 122static __inline__ void 123pcbit_tx_update(struct pcbit_dev *dev, ushort len) 124{ 125 u_char info; 126 127 dev->send_seq = (dev->send_seq + 1) % 8; 128 129 dev->fsize[dev->send_seq] = len; 130 info = 0; 131 info |= dev->rcv_seq << 3; 132 info |= dev->send_seq; 133 134 writeb(info, dev->sh_mem + BANK4); 135 136} 137 138/* 139 * called by interrupt service routine or by write_2 140 */ 141 142static void 143pcbit_transmit(struct pcbit_dev *dev) 144{ 145 struct frame_buf *frame = NULL; 146 unsigned char unacked; 147 int flen; /* fragment frame length including all headers */ 148 int free; 149 int count, 150 cp_len; 151 unsigned long flags; 152 unsigned short tt; 153 154 if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) 155 return; 156 157 unacked = (dev->send_seq + (8 - dev->unack_seq)) & 0x07; 158 159 spin_lock_irqsave(&dev->lock, flags); 160 161 if (dev->free > 16 && dev->write_queue && unacked < 7) { 162 163 if (!dev->w_busy) 164 dev->w_busy = 1; 165 else { 166 spin_unlock_irqrestore(&dev->lock, flags); 167 return; 168 } 169 170 171 frame = dev->write_queue; 172 free = dev->free; 173 174 spin_unlock_irqrestore(&dev->lock, flags); 175 176 if (frame->copied == 0) { 177 178 /* Type 0 frame */ 179 180 ulong msg; 181 182 if (frame->skb) 183 flen = FRAME_HDR_LEN + PREHDR_LEN + frame->skb->len; 184 else 185 flen = FRAME_HDR_LEN + PREHDR_LEN; 186 187 if (flen > free) 188 flen = free; 189 190 msg = frame->msg; 191 192 /* 193 * Board level 2 header 194 */ 195 196 pcbit_writew(dev, flen - FRAME_HDR_LEN); 197 198 pcbit_writeb(dev, GET_MSG_CPU(msg)); 199 200 pcbit_writeb(dev, GET_MSG_PROC(msg)); 201 202 /* TH */ 203 pcbit_writew(dev, frame->hdr_len + PREHDR_LEN); 204 205 /* TD */ 206 pcbit_writew(dev, frame->dt_len); 207 208 209 /* 210 * Board level 3 fixed-header 211 */ 212 213 /* LEN = TH */ 214 pcbit_writew(dev, frame->hdr_len + PREHDR_LEN); 215 216 /* XX */ 217 pcbit_writew(dev, 0); 218 219 /* C + S */ 220 pcbit_writeb(dev, GET_MSG_CMD(msg)); 221 pcbit_writeb(dev, GET_MSG_SCMD(msg)); 222 223 /* NUM */ 224 pcbit_writew(dev, frame->refnum); 225 226 count = FRAME_HDR_LEN + PREHDR_LEN; 227 } else { 228 /* Type 1 frame */ 229 230 flen = 2 + (frame->skb->len - frame->copied); 231 232 if (flen > free) 233 flen = free; 234 235 /* TT */ 236 tt = ((ushort) (flen - 2)) | 0x8000U; /* Type 1 */ 237 pcbit_writew(dev, tt); 238 239 count = 2; 240 } 241 242 if (frame->skb) { 243 cp_len = frame->skb->len - frame->copied; 244 if (cp_len > flen - count) 245 cp_len = flen - count; 246 247 memcpy_topcbit(dev, frame->skb->data + frame->copied, 248 cp_len); 249 frame->copied += cp_len; 250 } 251 /* bookkeeping */ 252 dev->free -= flen; 253 pcbit_tx_update(dev, flen); 254 255 spin_lock_irqsave(&dev->lock, flags); 256 257 if (frame->skb == NULL || frame->copied == frame->skb->len) { 258 259 dev->write_queue = frame->next; 260 261 if (frame->skb != NULL) { 262 /* free frame */ 263 dev_kfree_skb(frame->skb); 264 } 265 kfree(frame); 266 } 267 dev->w_busy = 0; 268 spin_unlock_irqrestore(&dev->lock, flags); 269 } else { 270 spin_unlock_irqrestore(&dev->lock, flags); 271#ifdef DEBUG 272 printk(KERN_DEBUG "unacked %d free %d write_queue %s\n", 273 unacked, dev->free, dev->write_queue ? "not empty" : 274 "empty"); 275#endif 276 } 277} 278 279 280/* 281 * deliver a queued frame to the upper layer 282 */ 283 284void 285pcbit_deliver(struct work_struct *work) 286{ 287 struct frame_buf *frame; 288 unsigned long flags, msg; 289 struct pcbit_dev *dev = 290 container_of(work, struct pcbit_dev, qdelivery); 291 292 spin_lock_irqsave(&dev->lock, flags); 293 294 while ((frame = dev->read_queue)) { 295 dev->read_queue = frame->next; 296 spin_unlock_irqrestore(&dev->lock, flags); 297 298 msg = 0; 299 SET_MSG_CPU(msg, 0); 300 SET_MSG_PROC(msg, 0); 301 SET_MSG_CMD(msg, frame->skb->data[2]); 302 SET_MSG_SCMD(msg, frame->skb->data[3]); 303 304 frame->refnum = *((ushort *) frame->skb->data + 4); 305 frame->msg = *((ulong *) & msg); 306 307 skb_pull(frame->skb, 6); 308 309 pcbit_l3_receive(dev, frame->msg, frame->skb, frame->hdr_len, 310 frame->refnum); 311 312 kfree(frame); 313 314 spin_lock_irqsave(&dev->lock, flags); 315 } 316 317 spin_unlock_irqrestore(&dev->lock, flags); 318} 319 320/* 321 * Reads BANK 2 & Reassembles 322 */ 323 324static void 325pcbit_receive(struct pcbit_dev *dev) 326{ 327 unsigned short tt; 328 u_char cpu, 329 proc; 330 struct frame_buf *frame = NULL; 331 unsigned long flags; 332 u_char type1; 333 334 if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) 335 return; 336 337 tt = pcbit_readw(dev); 338 339 if ((tt & 0x7fffU) > 511) { 340 printk(KERN_INFO "pcbit: invalid frame length -> TT=%04x\n", 341 tt); 342 pcbit_l2_error(dev); 343 return; 344 } 345 if (!(tt & 0x8000U)) { /* Type 0 */ 346 type1 = 0; 347 348 if (dev->read_frame) { 349 printk(KERN_DEBUG "pcbit_receive: Type 0 frame and read_frame != NULL\n"); 350 /* discard previous queued frame */ 351 kfree_skb(dev->read_frame->skb); 352 kfree(dev->read_frame); 353 dev->read_frame = NULL; 354 } 355 frame = kzalloc(sizeof(struct frame_buf), GFP_ATOMIC); 356 357 if (frame == NULL) { 358 printk(KERN_WARNING "kmalloc failed\n"); 359 return; 360 } 361 362 cpu = pcbit_readb(dev); 363 proc = pcbit_readb(dev); 364 365 366 if (cpu != 0x06 && cpu != 0x02) { 367 printk(KERN_DEBUG "pcbit: invalid cpu value\n"); 368 kfree(frame); 369 pcbit_l2_error(dev); 370 return; 371 } 372 /* 373 * we discard cpu & proc on receiving 374 * but we read it to update the pointer 375 */ 376 377 frame->hdr_len = pcbit_readw(dev); 378 frame->dt_len = pcbit_readw(dev); 379 380 /* 381 * 0 sized packet 382 * I don't know if they are an error or not... 383 * But they are very frequent 384 * Not documented 385 */ 386 387 if (frame->hdr_len == 0) { 388 kfree(frame); 389#ifdef DEBUG 390 printk(KERN_DEBUG "0 sized frame\n"); 391#endif 392 pcbit_firmware_bug(dev); 393 return; 394 } 395 /* sanity check the length values */ 396 if (frame->hdr_len > 1024 || frame->dt_len > 2048) { 397#ifdef DEBUG 398 printk(KERN_DEBUG "length problem: "); 399 printk(KERN_DEBUG "TH=%04x TD=%04x\n", 400 frame->hdr_len, 401 frame->dt_len); 402#endif 403 pcbit_l2_error(dev); 404 kfree(frame); 405 return; 406 } 407 /* minimum frame read */ 408 409 frame->skb = dev_alloc_skb(frame->hdr_len + frame->dt_len + 410 ((frame->hdr_len + 15) & ~15)); 411 412 if (!frame->skb) { 413 printk(KERN_DEBUG "pcbit_receive: out of memory\n"); 414 kfree(frame); 415 return; 416 } 417 /* 16 byte alignment for IP */ 418 if (frame->dt_len) 419 skb_reserve(frame->skb, (frame->hdr_len + 15) & ~15); 420 421 } else { 422 /* Type 1 */ 423 type1 = 1; 424 tt &= 0x7fffU; 425 426 if (!(frame = dev->read_frame)) { 427 printk("Type 1 frame and no frame queued\n"); 428 /* usually after an error: toss frame */ 429 dev->readptr += tt; 430 if (dev->readptr > dev->sh_mem + BANK2 + BANKLEN) 431 dev->readptr -= BANKLEN; 432 return; 433 434 } 435 } 436 437 memcpy_frompcbit(dev, skb_put(frame->skb, tt), tt); 438 439 frame->copied += tt; 440 spin_lock_irqsave(&dev->lock, flags); 441 if (frame->copied == frame->hdr_len + frame->dt_len) { 442 443 if (type1) { 444 dev->read_frame = NULL; 445 } 446 if (dev->read_queue) { 447 struct frame_buf *ptr; 448 for (ptr = dev->read_queue; ptr->next; ptr = ptr->next); 449 ptr->next = frame; 450 } else 451 dev->read_queue = frame; 452 453 } else { 454 dev->read_frame = frame; 455 } 456 spin_unlock_irqrestore(&dev->lock, flags); 457} 458 459/* 460 * The board sends 0 sized frames 461 * They are TDATA_CONFs that get messed up somehow 462 * gotta send a fake acknowledgment to the upper layer somehow 463 */ 464 465static __inline__ void 466pcbit_fake_conf(struct pcbit_dev *dev, struct pcbit_chan *chan) 467{ 468 isdn_ctrl ictl; 469 470 if (chan->queued) { 471 chan->queued--; 472 473 ictl.driver = dev->id; 474 ictl.command = ISDN_STAT_BSENT; 475 ictl.arg = chan->id; 476 dev->dev_if->statcallb(&ictl); 477 } 478} 479 480static void 481pcbit_firmware_bug(struct pcbit_dev *dev) 482{ 483 struct pcbit_chan *chan; 484 485 chan = dev->b1; 486 487 if (chan->fsm_state == ST_ACTIVE) { 488 pcbit_fake_conf(dev, chan); 489 } 490 chan = dev->b2; 491 492 if (chan->fsm_state == ST_ACTIVE) { 493 pcbit_fake_conf(dev, chan); 494 } 495} 496 497irqreturn_t 498pcbit_irq_handler(int interrupt, void *devptr) 499{ 500 struct pcbit_dev *dev; 501 u_char info, 502 ack_seq, 503 read_seq; 504 505 dev = (struct pcbit_dev *) devptr; 506 507 if (!dev) { 508 printk(KERN_WARNING "pcbit_irq_handler: wrong device\n"); 509 return IRQ_NONE; 510 } 511 if (dev->interrupt) { 512 printk(KERN_DEBUG "pcbit: reentering interrupt hander\n"); 513 return IRQ_HANDLED; 514 } 515 dev->interrupt = 1; 516 517 info = readb(dev->sh_mem + BANK3); 518 519 if (dev->l2_state == L2_STARTING || dev->l2_state == L2_ERROR) { 520 pcbit_l2_active_conf(dev, info); 521 dev->interrupt = 0; 522 return IRQ_HANDLED; 523 } 524 if (info & 0x40U) { /* E bit set */ 525#ifdef DEBUG 526 printk(KERN_DEBUG "pcbit_irq_handler: E bit on\n"); 527#endif 528 pcbit_l2_error(dev); 529 dev->interrupt = 0; 530 return IRQ_HANDLED; 531 } 532 if (dev->l2_state != L2_RUNNING && dev->l2_state != L2_LOADING) { 533 dev->interrupt = 0; 534 return IRQ_HANDLED; 535 } 536 ack_seq = (info >> 3) & 0x07U; 537 read_seq = (info & 0x07U); 538 539 dev->interrupt = 0; 540 541 if (read_seq != dev->rcv_seq) { 542 while (read_seq != dev->rcv_seq) { 543 pcbit_receive(dev); 544 dev->rcv_seq = (dev->rcv_seq + 1) % 8; 545 } 546 pcbit_sched_delivery(dev); 547 } 548 if (ack_seq != dev->unack_seq) { 549 pcbit_recv_ack(dev, ack_seq); 550 } 551 info = dev->rcv_seq << 3; 552 info |= dev->send_seq; 553 554 writeb(info, dev->sh_mem + BANK4); 555 return IRQ_HANDLED; 556} 557 558 559static void 560pcbit_l2_active_conf(struct pcbit_dev *dev, u_char info) 561{ 562 u_char state; 563 564 state = dev->l2_state; 565 566#ifdef DEBUG 567 printk(KERN_DEBUG "layer2_active_confirm\n"); 568#endif 569 570 571 if (info & 0x80U) { 572 dev->rcv_seq = info & 0x07U; 573 dev->l2_state = L2_RUNNING; 574 } else 575 dev->l2_state = L2_DOWN; 576 577 if (state == L2_STARTING) 578 wake_up_interruptible(&dev->set_running_wq); 579 580 if (state == L2_ERROR && dev->l2_state == L2_RUNNING) { 581 pcbit_transmit(dev); 582 } 583} 584 585static void 586pcbit_l2_err_recover(unsigned long data) 587{ 588 589 struct pcbit_dev *dev; 590 struct frame_buf *frame; 591 592 dev = (struct pcbit_dev *) data; 593 594 del_timer(&dev->error_recover_timer); 595 if (dev->w_busy || dev->r_busy) { 596 init_timer(&dev->error_recover_timer); 597 dev->error_recover_timer.expires = jiffies + ERRTIME; 598 add_timer(&dev->error_recover_timer); 599 return; 600 } 601 dev->w_busy = dev->r_busy = 1; 602 603 if (dev->read_frame) { 604 kfree_skb(dev->read_frame->skb); 605 kfree(dev->read_frame); 606 dev->read_frame = NULL; 607 } 608 if (dev->write_queue) { 609 frame = dev->write_queue; 610#ifdef FREE_ON_ERROR 611 dev->write_queue = dev->write_queue->next; 612 613 if (frame->skb) { 614 dev_kfree_skb(frame->skb); 615 } 616 kfree(frame); 617#else 618 frame->copied = 0; 619#endif 620 } 621 dev->rcv_seq = dev->send_seq = dev->unack_seq = 0; 622 dev->free = 511; 623 dev->l2_state = L2_ERROR; 624 625 /* this is an hack... */ 626 pcbit_firmware_bug(dev); 627 628 dev->writeptr = dev->sh_mem; 629 dev->readptr = dev->sh_mem + BANK2; 630 631 writeb((0x80U | ((dev->rcv_seq & 0x07) << 3) | (dev->send_seq & 0x07)), 632 dev->sh_mem + BANK4); 633 dev->w_busy = dev->r_busy = 0; 634 635} 636 637static void 638pcbit_l2_error(struct pcbit_dev *dev) 639{ 640 if (dev->l2_state == L2_RUNNING) { 641 642 printk(KERN_INFO "pcbit: layer 2 error\n"); 643 644#ifdef DEBUG 645 log_state(dev); 646#endif 647 648 dev->l2_state = L2_DOWN; 649 650 init_timer(&dev->error_recover_timer); 651 dev->error_recover_timer.function = &pcbit_l2_err_recover; 652 dev->error_recover_timer.data = (ulong) dev; 653 dev->error_recover_timer.expires = jiffies + ERRTIME; 654 add_timer(&dev->error_recover_timer); 655 } 656} 657 658/* 659 * Description: 660 * if board acks frames 661 * update dev->free 662 * call pcbit_transmit to write possible queued frames 663 */ 664 665static void 666pcbit_recv_ack(struct pcbit_dev *dev, unsigned char ack) 667{ 668 int i, 669 count; 670 int unacked; 671 672 unacked = (dev->send_seq + (8 - dev->unack_seq)) & 0x07; 673 674 /* dev->unack_seq < ack <= dev->send_seq; */ 675 676 if (unacked) { 677 678 if (dev->send_seq > dev->unack_seq) { 679 if (ack <= dev->unack_seq || ack > dev->send_seq) { 680 printk(KERN_DEBUG 681 "layer 2 ack unacceptable - dev %d", 682 dev->id); 683 684 pcbit_l2_error(dev); 685 } else if (ack > dev->send_seq && ack <= dev->unack_seq) { 686 printk(KERN_DEBUG 687 "layer 2 ack unacceptable - dev %d", 688 dev->id); 689 pcbit_l2_error(dev); 690 } 691 } 692 /* ack is acceptable */ 693 694 695 i = dev->unack_seq; 696 697 do { 698 dev->unack_seq = i = (i + 1) % 8; 699 dev->free += dev->fsize[i]; 700 } while (i != ack); 701 702 count = 0; 703 while (count < 7 && dev->write_queue) { 704 u8 lsend_seq = dev->send_seq; 705 706 pcbit_transmit(dev); 707 708 if (dev->send_seq == lsend_seq) 709 break; 710 count++; 711 } 712 } else 713 printk(KERN_DEBUG "recv_ack: unacked = 0\n"); 714} 715