1 /* if_en.c 4.35 82/03/03 */ 2 3 #include "en.h" 4 5 /* 6 * Xerox prototype (3 Mb) Ethernet interface driver. 7 */ 8 9 #include "../h/param.h" 10 #include "../h/systm.h" 11 #include "../h/mbuf.h" 12 #include "../h/pte.h" 13 #include "../h/buf.h" 14 #include "../h/protosw.h" 15 #include "../h/socket.h" 16 #include "../h/ubareg.h" 17 #include "../h/ubavar.h" 18 #include "../h/enreg.h" 19 #include "../h/cpu.h" 20 #include "../h/mtpr.h" 21 #include "../h/vmmac.h" 22 #include "../net/in.h" 23 #include "../net/in_systm.h" 24 #include "../net/if.h" 25 #include "../net/if_en.h" 26 #include "../net/if_uba.h" 27 #include "../net/ip.h" 28 #include "../net/ip_var.h" 29 30 #define ENMTU (1024+512) 31 32 int enprobe(), enattach(), enrint(), enxint(), encollide(); 33 struct uba_device *eninfo[NEN]; 34 u_short enstd[] = { 0 }; 35 struct uba_driver endriver = 36 { enprobe, 0, enattach, 0, enstd, "en", eninfo }; 37 #define ENUNIT(x) minor(x) 38 39 int eninit(),enoutput(),enreset(); 40 41 /* 42 * Ethernet software status per interface. 43 * 44 * Each interface is referenced by a network interface structure, 45 * es_if, which the routing code uses to locate the interface. 46 * This structure contains the output queue for the interface, its address, ... 47 * We also have, for each interface, a UBA interface structure, which 48 * contains information about the UNIBUS resources held by the interface: 49 * map registers, buffered data paths, etc. Information is cached in this 50 * structure for use by the if_uba.c routines in running the interface 51 * efficiently. 52 */ 53 struct en_softc { 54 struct ifnet es_if; /* network-visible interface */ 55 struct ifuba es_ifuba; /* UNIBUS resources */ 56 short es_delay; /* current output delay */ 57 short es_mask; /* mask for current output delay */ 58 u_char es_lastx; /* host last transmitted to */ 59 short es_oactive; /* is output active? */ 60 short es_olen; /* length of last output */ 61 } en_softc[NEN]; 62 63 /* 64 * Do output DMA to determine interface presence and 65 * interrupt vector. DMA is too short to disturb other hosts. 66 */ 67 enprobe(reg) 68 caddr_t reg; 69 { 70 register int br, cvec; /* r11, r10 value-result */ 71 register struct endevice *addr = (struct endevice *)reg; 72 73 COUNT(ENPROBE); 74 #ifdef lint 75 br = 0; cvec = br; br = cvec; 76 enrint(0); enxint(0); encollide(0); 77 #endif 78 addr->en_istat = 0; 79 addr->en_owc = -1; 80 addr->en_oba = 0; 81 addr->en_ostat = EN_IEN|EN_GO; 82 DELAY(100000); 83 addr->en_ostat = 0; 84 return (1); 85 } 86 87 /* 88 * Interface exists: make available by filling in network interface 89 * record. System will initialize the interface when it is ready 90 * to accept packets. 91 */ 92 enattach(ui) 93 struct uba_device *ui; 94 { 95 register struct en_softc *es = &en_softc[ui->ui_unit]; 96 COUNT(ENATTACH); 97 98 es->es_if.if_unit = ui->ui_unit; 99 es->es_if.if_name = "en"; 100 es->es_if.if_mtu = ENMTU; 101 es->es_if.if_net = ui->ui_flags; 102 es->es_if.if_host[0] = 103 (~(((struct endevice *)eninfo[ui->ui_unit]->ui_addr)->en_addr)) & 0xff; 104 #ifdef ENKLUDGE 105 if (es->es_if.if_net == 10) { 106 es->es_if.if_host[0] <<= 16; 107 es->es_if.if_host[0] |= 0x4e; 108 } 109 #endif 110 es->es_if.if_addr = 111 if_makeaddr(es->es_if.if_net, es->es_if.if_host[0]); 112 es->es_if.if_init = eninit; 113 es->es_if.if_output = enoutput; 114 es->es_if.if_ubareset = enreset; 115 es->es_ifuba.ifu_flags = UBA_NEEDBDP | UBA_NEED16; 116 if_attach(&es->es_if); 117 } 118 119 /* 120 * Reset of interface after UNIBUS reset. 121 * If interface is on specified uba, reset its state. 122 */ 123 enreset(unit, uban) 124 int unit, uban; 125 { 126 register struct uba_device *ui; 127 COUNT(ENRESET); 128 129 if (unit >= NEN || (ui = eninfo[unit]) == 0 || ui->ui_alive == 0 || 130 ui->ui_ubanum != uban) 131 return; 132 printf(" en%d", unit); 133 eninit(unit); 134 } 135 136 /* 137 * Initialization of interface; clear recorded pending 138 * operations, and reinitialize UNIBUS usage. 139 */ 140 eninit(unit) 141 int unit; 142 { 143 register struct en_softc *es = &en_softc[unit]; 144 register struct uba_device *ui = eninfo[unit]; 145 register struct endevice *addr; 146 int s; 147 148 if (if_ubainit(&es->es_ifuba, ui->ui_ubanum, 149 sizeof (struct en_header), (int)btoc(ENMTU)) == 0) { 150 printf("en%d: can't initialize\n", unit); 151 return; 152 } 153 addr = (struct endevice *)ui->ui_addr; 154 addr->en_istat = addr->en_ostat = 0; 155 156 /* 157 * Hang a receive and start any 158 * pending writes by faking a transmit complete. 159 */ 160 s = splimp(); 161 addr->en_iba = es->es_ifuba.ifu_r.ifrw_info; 162 addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1; 163 addr->en_istat = EN_IEN|EN_GO; 164 es->es_oactive = 1; 165 enxint(unit); 166 splx(s); 167 } 168 169 int enlastdel = 25; 170 171 /* 172 * Start or restart output on interface. 173 * If interface is already active, then this is a retransmit 174 * after a collision, and just restuff registers and delay. 175 * If interface is not already active, get another datagram 176 * to send off of the interface queue, and map it to the interface 177 * before starting the output. 178 */ 179 enstart(dev) 180 dev_t dev; 181 { 182 int unit = ENUNIT(dev); 183 struct uba_device *ui = eninfo[unit]; 184 register struct en_softc *es = &en_softc[unit]; 185 register struct endevice *addr; 186 struct mbuf *m; 187 int dest; 188 COUNT(ENSTART); 189 190 if (es->es_oactive) 191 goto restart; 192 193 /* 194 * Not already active: dequeue another request 195 * and map it to the UNIBUS. If no more requests, 196 * just return. 197 */ 198 IF_DEQUEUE(&es->es_if.if_snd, m); 199 if (m == 0) { 200 es->es_oactive = 0; 201 return; 202 } 203 dest = mtod(m, struct en_header *)->en_dhost; 204 es->es_olen = if_wubaput(&es->es_ifuba, m); 205 206 /* 207 * Ethernet cannot take back-to-back packets (no 208 * buffering in interface. To avoid overrunning 209 * receiver, enforce a small delay (about 1ms) in interface 210 * on successive packets sent to same host. 211 */ 212 if (es->es_lastx && es->es_lastx == dest) 213 es->es_delay = enlastdel; 214 else 215 es->es_lastx = dest; 216 217 restart: 218 /* 219 * Have request mapped to UNIBUS for transmission. 220 * Purge any stale data from this BDP, and start the otput. 221 */ 222 UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_w.ifrw_bdp); 223 addr = (struct endevice *)ui->ui_addr; 224 addr->en_oba = (int)es->es_ifuba.ifu_w.ifrw_info; 225 addr->en_odelay = es->es_delay; 226 addr->en_owc = -((es->es_olen + 1) >> 1); 227 addr->en_ostat = EN_IEN|EN_GO; 228 es->es_oactive = 1; 229 } 230 231 /* 232 * Ethernet interface transmitter interrupt. 233 * Start another output if more data to send. 234 */ 235 enxint(unit) 236 int unit; 237 { 238 register struct uba_device *ui = eninfo[unit]; 239 register struct en_softc *es = &en_softc[unit]; 240 register struct endevice *addr; 241 COUNT(ENXINT); 242 243 if (es->es_oactive == 0) 244 return; 245 addr = (struct endevice *)ui->ui_addr; 246 es->es_if.if_opackets++; 247 es->es_oactive = 0; 248 es->es_delay = 0; 249 es->es_mask = ~0; 250 if (addr->en_ostat&EN_OERROR) { 251 es->es_if.if_oerrors++; 252 printf("en%d: output error\n", unit); 253 } 254 if (es->es_ifuba.ifu_xtofree) { 255 m_freem(es->es_ifuba.ifu_xtofree); 256 es->es_ifuba.ifu_xtofree = 0; 257 } 258 if (es->es_if.if_snd.ifq_head == 0) { 259 es->es_lastx = 0; 260 return; 261 } 262 enstart(unit); 263 } 264 265 /* 266 * Collision on ethernet interface. Do exponential 267 * backoff, and retransmit. If have backed off all 268 * the way printing warning diagnostic, and drop packet. 269 */ 270 encollide(unit) 271 int unit; 272 { 273 register struct en_softc *es = &en_softc[unit]; 274 COUNT(ENCOLLIDE); 275 276 es->es_if.if_collisions++; 277 if (es->es_oactive == 0) 278 return; 279 /* 280 * Es_mask is a 16 bit number with n low zero bits, with 281 * n the number of backoffs. When es_mask is 0 we have 282 * backed off 16 times, and give up. 283 */ 284 if (es->es_mask == 0) { 285 printf("en%d: send error\n", unit); 286 enxint(unit); 287 return; 288 } 289 /* 290 * Another backoff. Restart with delay based on n low bits 291 * of the interval timer. 292 */ 293 es->es_mask <<= 1; 294 es->es_delay = mfpr(ICR) &~ es->es_mask; 295 enstart(unit); 296 } 297 298 int enprintierrors; 299 /* 300 * Ethernet interface receiver interrupt. 301 * If input error just drop packet. 302 * Otherwise purge input buffered data path and examine 303 * packet to determine type. If can't determine length 304 * from type, then have to drop packet. Othewise decapsulate 305 * packet based on type and pass to type specific higher-level 306 * input routine. 307 */ 308 enrint(unit) 309 int unit; 310 { 311 register struct en_softc *es = &en_softc[unit]; 312 struct endevice *addr = (struct endevice *)eninfo[unit]->ui_addr; 313 register struct en_header *en; 314 struct mbuf *m; 315 int len; 316 register struct ifqueue *inq; 317 int off; 318 COUNT(ENRINT); 319 320 es->es_if.if_ipackets++; 321 322 /* 323 * Purge BDP; drop if input error indicated. 324 */ 325 UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_r.ifrw_bdp); 326 if (addr->en_istat&EN_IERROR) { 327 es->es_if.if_ierrors++; 328 if (enprintierrors) 329 printf("en%d: input error\n", unit); 330 goto setup; 331 } 332 333 /* 334 * Get pointer to ethernet header (in input buffer). 335 * Deal with trailer protocol: if type is PUP trailer 336 * get true type from first 16-bit word past data. 337 * Remember that type was trailer by setting off. 338 */ 339 en = (struct en_header *)(es->es_ifuba.ifu_r.ifrw_addr); 340 #define endataaddr(en, off, type) ((type)(((caddr_t)((en)+1)+(off)))) 341 if (en->en_type >= ENPUP_TRAIL && 342 en->en_type < ENPUP_TRAIL+ENPUP_NTRAILER) { 343 off = (en->en_type - ENPUP_TRAIL) * 512; 344 if (off >= ENMTU) 345 goto setup; /* sanity */ 346 en->en_type = *endataaddr(en, off, u_short *); 347 } else 348 off = 0; 349 350 /* 351 * Attempt to infer packet length from type; 352 * can't deal with packet if can't infer length. 353 */ 354 switch (en->en_type) { 355 356 #ifdef INET 357 case ENPUP_IPTYPE: 358 len = htons((u_short)endataaddr(en, off ? off+2 : 0, struct ip *)->ip_len); 359 if (off) 360 len += 2; 361 setipintr(); 362 inq = &ipintrq; 363 break; 364 #endif 365 366 default: 367 printf("en%d: unknown pkt type 0x%x\n", unit, en->en_type); 368 goto setup; 369 } 370 if (len == 0) 371 goto setup; 372 373 /* 374 * Pull packet off interface. Off is nonzero if packet 375 * has trailing header; if_rubaget will then force this header 376 * information to be at the front, but we still have to drop 377 * the two-byte type which is at the front of any trailer data. 378 */ 379 m = if_rubaget(&es->es_ifuba, len, off); 380 if (m == 0) 381 goto setup; 382 if (off) { 383 m->m_off += 2; 384 m->m_len -= 2; 385 } 386 IF_ENQUEUE(inq, m); 387 388 setup: 389 /* 390 * Reset for next packet. 391 */ 392 addr->en_iba = es->es_ifuba.ifu_r.ifrw_info; 393 addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1; 394 addr->en_istat = EN_IEN|EN_GO; 395 } 396 397 /* 398 * Ethernet output routine. 399 * Encapsulate a packet of type family for the local net. 400 * Use trailer local net encapsulation if enough data in first 401 * packet leaves a multiple of 512 bytes of data in remainder. 402 */ 403 enoutput(ifp, m0, pf) 404 struct ifnet *ifp; 405 struct mbuf *m0; 406 int pf; 407 { 408 int type, dest; 409 register struct mbuf *m = m0; 410 register struct en_header *en; 411 int s; 412 413 COUNT(ENOUTPUT); 414 switch (pf) { 415 416 #ifdef INET 417 case PF_INET: { 418 register struct ip *ip = mtod(m0, struct ip *); 419 int off; 420 421 #ifndef ENKLUDGE 422 dest = ip->ip_dst.s_addr >> 24; 423 #else 424 dest = (ip->ip_dst.s_addr >> 8) & 0xff; 425 #endif 426 off = ntohs((u_short)ip->ip_len) - m->m_len; 427 #ifndef ENKLUDGE 428 if (off > 0 && (off & 0x1ff) == 0 && m->m_off >= MMINOFF + 2) { 429 type = ENPUP_TRAIL + (off>>9); 430 m->m_off -= 2; 431 m->m_len += 2; 432 *mtod(m, u_short *) = ENPUP_IPTYPE; 433 goto gottrailertype; 434 } 435 #endif 436 type = ENPUP_IPTYPE; 437 off = 0; 438 goto gottype; 439 } 440 #endif 441 442 default: 443 printf("en%d: can't encapsulate pf%d\n", ifp->if_unit, pf); 444 m_freem(m0); 445 return (0); 446 } 447 448 gottrailertype: 449 /* 450 * Packet to be sent as trailer: move first packet 451 * (control information) to end of chain. 452 */ 453 while (m->m_next) 454 m = m->m_next; 455 m->m_next = m0; 456 m = m0->m_next; 457 m0->m_next = 0; 458 m0 = m; 459 460 gottype: 461 /* 462 * Add local net header. If no space in first mbuf, 463 * allocate another. 464 */ 465 if (m->m_off > MMAXOFF || 466 MMINOFF + sizeof (struct en_header) > m->m_off) { 467 m = m_get(M_DONTWAIT); 468 if (m == 0) { 469 m_freem(m0); 470 return (0); 471 } 472 m->m_next = m0; 473 m->m_off = MMINOFF; 474 m->m_len = sizeof (struct en_header); 475 } else { 476 m->m_off -= sizeof (struct en_header); 477 m->m_len += sizeof (struct en_header); 478 } 479 en = mtod(m, struct en_header *); 480 en->en_shost = ifp->if_host[0]; 481 en->en_dhost = dest; 482 en->en_type = type; 483 484 /* 485 * Queue message on interface, and start output if interface 486 * not yet active. 487 */ 488 s = splimp(); 489 IF_ENQUEUE(&ifp->if_snd, m); 490 if (en_softc[ifp->if_unit].es_oactive == 0) 491 enstart(ifp->if_unit); 492 splx(s); 493 return (1); 494 } 495