1 /* if_en.c 4.31 82/01/30 */ 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 if_attach(&es->es_if); 116 } 117 118 /* 119 * Reset of interface after UNIBUS reset. 120 * If interface is on specified uba, reset its state. 121 */ 122 enreset(unit, uban) 123 int unit, uban; 124 { 125 register struct uba_device *ui; 126 COUNT(ENRESET); 127 128 if (unit >= NEN || (ui = eninfo[unit]) == 0 || ui->ui_alive == 0 || 129 ui->ui_ubanum != uban) 130 return; 131 printf(" en%d", unit); 132 eninit(unit); 133 } 134 135 /* 136 * Initialization of interface; clear recorded pending 137 * operations, and reinitialize UNIBUS usage. 138 */ 139 eninit(unit) 140 int unit; 141 { 142 register struct en_softc *es = &en_softc[unit]; 143 register struct uba_device *ui = eninfo[unit]; 144 register struct endevice *addr; 145 int s; 146 147 if (if_ubainit(&es->es_ifuba, ui->ui_ubanum, 148 sizeof (struct en_header), (int)btop(ENMTU)) == 0) { 149 printf("en%d: can't initialize\n", unit); 150 return; 151 } 152 addr = (struct endevice *)ui->ui_addr; 153 addr->en_istat = addr->en_ostat = 0; 154 155 /* 156 * Hang a receive and start any 157 * pending writes by faking a transmit complete. 158 */ 159 s = splimp(); 160 addr->en_iba = es->es_ifuba.ifu_r.ifrw_info; 161 addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1; 162 addr->en_istat = EN_IEN|EN_GO; 163 es->es_oactive = 1; 164 enxint(unit); 165 splx(s); 166 } 167 168 int enlastdel = 25; 169 170 /* 171 * Start or restart output on interface. 172 * If interface is already active, then this is a retransmit 173 * after a collision, and just restuff registers and delay. 174 * If interface is not already active, get another datagram 175 * to send off of the interface queue, and map it to the interface 176 * before starting the output. 177 */ 178 enstart(dev) 179 dev_t dev; 180 { 181 int unit = ENUNIT(dev); 182 struct uba_device *ui = eninfo[unit]; 183 register struct en_softc *es = &en_softc[unit]; 184 register struct endevice *addr; 185 struct mbuf *m; 186 int dest; 187 COUNT(ENSTART); 188 189 if (es->es_oactive) 190 goto restart; 191 192 /* 193 * Not already active: dequeue another request 194 * and map it to the UNIBUS. If no more requests, 195 * just return. 196 */ 197 IF_DEQUEUE(&es->es_if.if_snd, m); 198 if (m == 0) { 199 es->es_oactive = 0; 200 return; 201 } 202 dest = mtod(m, struct en_header *)->en_dhost; 203 es->es_olen = if_wubaput(&es->es_ifuba, m); 204 205 /* 206 * Ethernet cannot take back-to-back packets (no 207 * buffering in interface. To avoid overrunning 208 * receiver, enforce a small delay (about 1ms) in interface 209 * on successive packets sent to same host. 210 */ 211 if (es->es_lastx && es->es_lastx == dest) 212 es->es_delay = enlastdel; 213 else 214 es->es_lastx = dest; 215 216 restart: 217 /* 218 * Have request mapped to UNIBUS for transmission. 219 * Purge any stale data from this BDP, and start the otput. 220 */ 221 UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_w.ifrw_bdp); 222 addr = (struct endevice *)ui->ui_addr; 223 addr->en_oba = (int)es->es_ifuba.ifu_w.ifrw_info; 224 addr->en_odelay = es->es_delay; 225 addr->en_owc = -((es->es_olen + 1) >> 1); 226 addr->en_ostat = EN_IEN|EN_GO; 227 es->es_oactive = 1; 228 } 229 230 /* 231 * Ethernet interface transmitter interrupt. 232 * Start another output if more data to send. 233 */ 234 enxint(unit) 235 int unit; 236 { 237 register struct uba_device *ui = eninfo[unit]; 238 register struct en_softc *es = &en_softc[unit]; 239 register struct endevice *addr; 240 COUNT(ENXINT); 241 242 if (es->es_oactive == 0) 243 return; 244 addr = (struct endevice *)ui->ui_addr; 245 es->es_if.if_opackets++; 246 es->es_oactive = 0; 247 es->es_delay = 0; 248 es->es_mask = ~0; 249 if (addr->en_ostat&EN_OERROR) { 250 es->es_if.if_oerrors++; 251 printf("en%d: output error\n", unit); 252 } 253 if (es->es_if.if_snd.ifq_head == 0) { 254 if (es->es_ifuba.ifu_xtofree) { 255 m_freem(es->es_ifuba.ifu_xtofree); 256 es->es_ifuba.ifu_xtofree = 0; 257 } 258 es->es_lastx = 0; 259 return; 260 } 261 enstart(unit); 262 } 263 264 /* 265 * Collision on ethernet interface. Do exponential 266 * backoff, and retransmit. If have backed off all 267 * the way printing warning diagnostic, and drop packet. 268 */ 269 encollide(unit) 270 int unit; 271 { 272 register struct en_softc *es = &en_softc[unit]; 273 COUNT(ENCOLLIDE); 274 275 es->es_if.if_collisions++; 276 if (es->es_oactive == 0) 277 return; 278 /* 279 * Es_mask is a 16 bit number with n low zero bits, with 280 * n the number of backoffs. When es_mask is 0 we have 281 * backed off 16 times, and give up. 282 */ 283 if (es->es_mask == 0) { 284 printf("en%d: send error\n", unit); 285 enxint(unit); 286 return; 287 } 288 /* 289 * Another backoff. Restart with delay based on n low bits 290 * of the interval timer. 291 */ 292 es->es_mask <<= 1; 293 es->es_delay = mfpr(ICR) &~ es->es_mask; 294 enstart(unit); 295 } 296 297 int enprintierrors; 298 /* 299 * Ethernet interface receiver interrupt. 300 * If input error just drop packet. 301 * Otherwise purge input buffered data path and examine 302 * packet to determine type. If can't determine length 303 * from type, then have to drop packet. Othewise decapsulate 304 * packet based on type and pass to type specific higher-level 305 * input routine. 306 */ 307 enrint(unit) 308 int unit; 309 { 310 register struct en_softc *es = &en_softc[unit]; 311 struct endevice *addr = (struct endevice *)eninfo[unit]->ui_addr; 312 register struct en_header *en; 313 struct mbuf *m; 314 int len; 315 register struct ifqueue *inq; 316 int off; 317 COUNT(ENRINT); 318 319 es->es_if.if_ipackets++; 320 321 /* 322 * Purge BDP; drop if input error indicated. 323 */ 324 UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_r.ifrw_bdp); 325 if (addr->en_istat&EN_IERROR) { 326 es->es_if.if_ierrors++; 327 if (enprintierrors) 328 printf("en%d: input error\n", unit); 329 goto setup; 330 } 331 332 /* 333 * Get pointer to ethernet header (in input buffer). 334 * Deal with trailer protocol: if type is PUP trailer 335 * get true type from first 16-bit word past data. 336 * Remember that type was trailer by setting off. 337 */ 338 en = (struct en_header *)(es->es_ifuba.ifu_r.ifrw_addr); 339 #define endataaddr(en, off, type) ((type)(((caddr_t)((en)+1)+(off)))) 340 if (en->en_type >= ENPUP_TRAIL && 341 en->en_type < ENPUP_TRAIL+ENPUP_NTRAILER) { 342 off = (en->en_type - ENPUP_TRAIL) * 512; 343 if (off >= ENMTU) 344 goto setup; /* sanity */ 345 en->en_type = *endataaddr(en, off, u_short *); 346 } else 347 off = 0; 348 349 /* 350 * Attempt to infer packet length from type; 351 * can't deal with packet if can't infer length. 352 */ 353 switch (en->en_type) { 354 355 #ifdef INET 356 case ENPUP_IPTYPE: 357 len = htons((u_short)endataaddr(en, off ? off+2 : 0, struct ip *)->ip_len); 358 if (off) 359 len += 2; 360 setipintr(); 361 inq = &ipintrq; 362 break; 363 #endif 364 365 default: 366 printf("en%d: unknow pkt type 0x%x\n", en->en_type); 367 goto setup; 368 } 369 if (len == 0) 370 goto setup; 371 372 /* 373 * Pull packet off interface. Off is nonzero if packet 374 * has trailing header; if_rubaget will then force this header 375 * information to be at the front, but we still have to drop 376 * the two-byte type which is at the front of any trailer data. 377 */ 378 m = if_rubaget(&es->es_ifuba, len, off); 379 if (m == 0) 380 goto setup; 381 if (off) { 382 m->m_off += 2; 383 m->m_len -= 2; 384 } 385 IF_ENQUEUE(inq, m); 386 387 setup: 388 /* 389 * Reset for next packet. 390 */ 391 addr->en_iba = es->es_ifuba.ifu_r.ifrw_info; 392 addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1; 393 addr->en_istat = EN_IEN|EN_GO; 394 } 395 396 /* 397 * Ethernet output routine. 398 * Encapsulate a packet of type family for the local net. 399 * Use trailer local net encapsulation if enough data in first 400 * packet leaves a multiple of 512 bytes of data in remainder. 401 */ 402 enoutput(ifp, m0, pf) 403 struct ifnet *ifp; 404 struct mbuf *m0; 405 int pf; 406 { 407 int type, dest; 408 register struct mbuf *m = m0; 409 register struct en_header *en; 410 int s; 411 412 switch (pf) { 413 414 #ifdef INET 415 case PF_INET: { 416 register struct ip *ip = mtod(m0, struct ip *); 417 int off; 418 419 #ifndef ENKLUDGE 420 dest = ip->ip_dst.s_addr >> 24; 421 #else 422 dest = (ip->ip_dst.s_addr >> 8) & 0xff; 423 #endif 424 off = ntohs((u_short)ip->ip_len) - m->m_len; 425 #ifndef ENKLUDGE 426 if (off > 0 && (off & 0x1ff) == 0 && m->m_off >= MMINOFF + 2) { 427 type = ENPUP_TRAIL + (off>>9); 428 m->m_off -= 2; 429 m->m_len += 2; 430 *mtod(m, u_short *) = ENPUP_IPTYPE; 431 goto gottrailertype; 432 } 433 #endif 434 type = ENPUP_IPTYPE; 435 off = 0; 436 goto gottype; 437 } 438 #endif 439 440 default: 441 printf("en%d: can't encapsulate pf%d\n", ifp->if_unit, pf); 442 m_freem(m0); 443 return (0); 444 } 445 446 gottrailertype: 447 /* 448 * Packet to be sent as trailer: move first packet 449 * (control information) to end of chain. 450 */ 451 while (m->m_next) 452 m = m->m_next; 453 m->m_next = m0; 454 m = m0->m_next; 455 m0->m_next = 0; 456 m0 = m; 457 458 gottype: 459 /* 460 * Add local net header. If no space in first mbuf, 461 * allocate another. 462 */ 463 if (m->m_off > MMAXOFF || 464 MMINOFF + sizeof (struct en_header) > m->m_off) { 465 m = m_get(M_DONTWAIT); 466 if (m == 0) { 467 m_freem(m0); 468 return (0); 469 } 470 m->m_next = m0; 471 m->m_off = MMINOFF; 472 m->m_len = sizeof (struct en_header); 473 } else { 474 m->m_off -= sizeof (struct en_header); 475 m->m_len += sizeof (struct en_header); 476 } 477 en = mtod(m, struct en_header *); 478 en->en_shost = ifp->if_host[0]; 479 en->en_dhost = dest; 480 en->en_type = type; 481 482 /* 483 * Queue message on interface, and start output if interface 484 * not yet active. 485 */ 486 s = splimp(); 487 IF_ENQUEUE(&ifp->if_snd, m); 488 if (en_softc[ifp->if_unit].es_oactive == 0) 489 enstart(ifp->if_unit); 490 splx(s); 491 return (1); 492 } 493