1 /* if_en.c 4.27 81/12/22 */ 2 3 #define ENKLUDGE 4 #include "en.h" 5 6 /* 7 * Xerox prototype (3 Mb) Ethernet interface driver. 8 */ 9 10 #include "../h/param.h" 11 #include "../h/systm.h" 12 #include "../h/mbuf.h" 13 #include "../h/pte.h" 14 #include "../h/buf.h" 15 #include "../h/protosw.h" 16 #include "../h/socket.h" 17 #include "../h/ubareg.h" 18 #include "../h/ubavar.h" 19 #include "../h/enreg.h" 20 #include "../h/cpu.h" 21 #include "../h/mtpr.h" 22 #include "../h/vmmac.h" 23 #include "../net/in.h" 24 #include "../net/in_systm.h" 25 #include "../net/if.h" 26 #include "../net/if_en.h" 27 #include "../net/if_uba.h" 28 #include "../net/ip.h" 29 #include "../net/ip_var.h" 30 31 #define ENMTU (1024+512) 32 33 int enprobe(), enattach(), enrint(), enxint(), encollide(); 34 struct uba_device *eninfo[NEN]; 35 u_short enstd[] = { 0 }; 36 struct uba_driver endriver = 37 { enprobe, 0, enattach, 0, enstd, "en", eninfo }; 38 #define ENUNIT(x) minor(x) 39 40 int eninit(),enoutput(),enreset(); 41 42 /* 43 * Ethernet software status per interface. 44 * 45 * Each interface is referenced by a network interface structure, 46 * es_if, which the routing code uses to locate the interface. 47 * This structure contains the output queue for the interface, its address, ... 48 * We also have, for each interface, a UBA interface structure, which 49 * contains information about the UNIBUS resources held by the interface: 50 * map registers, buffered data paths, etc. Information is cached in this 51 * structure for use by the if_uba.c routines in running the interface 52 * efficiently. 53 */ 54 struct en_softc { 55 struct ifnet es_if; /* network-visible interface */ 56 struct ifuba es_ifuba; /* UNIBUS resources */ 57 short es_delay; /* current output delay */ 58 short es_mask; /* mask for current output delay */ 59 u_char es_lastx; /* host last transmitted to */ 60 short es_oactive; /* is output active? */ 61 short es_olen; /* length of last output */ 62 } en_softc[NEN]; 63 64 /* 65 * Do output DMA to determine interface presence and 66 * interrupt vector. DMA is too short to disturb other hosts. 67 */ 68 enprobe(reg) 69 caddr_t reg; 70 { 71 register int br, cvec; /* r11, r10 value-result */ 72 register struct endevice *addr = (struct endevice *)reg; 73 74 COUNT(ENPROBE); 75 #ifdef lint 76 br = 0; cvec = br; br = cvec; 77 enrint(0); enxint(0); encollide(0); 78 #endif 79 addr->en_istat = 0; 80 addr->en_owc = -1; 81 addr->en_oba = 0; 82 addr->en_ostat = EN_IEN|EN_GO; 83 DELAY(100000); 84 addr->en_ostat = 0; 85 return (1); 86 } 87 88 /* 89 * Interface exists: make available by filling in network interface 90 * record. System will initialize the interface when it is ready 91 * to accept packets. 92 */ 93 enattach(ui) 94 struct uba_device *ui; 95 { 96 register struct en_softc *es = &en_softc[ui->ui_unit]; 97 COUNT(ENATTACH); 98 99 es->es_if.if_unit = ui->ui_unit; 100 es->es_if.if_name = "en"; 101 es->es_if.if_mtu = ENMTU; 102 es->es_if.if_net = ui->ui_flags; 103 es->es_if.if_host[0] = 104 (~(((struct endevice *)eninfo[ui->ui_unit]->ui_addr)->en_addr)) & 0xff; 105 #ifdef ENKLUDGE 106 if (es->es_if.if_net == 10) { 107 es->es_if.if_host[0] <<= 16; 108 es->es_if.if_host[0] |= 0x4e; 109 } 110 #endif 111 es->es_if.if_addr = 112 if_makeaddr(es->es_if.if_net, es->es_if.if_host[0]); 113 es->es_if.if_init = eninit; 114 es->es_if.if_output = enoutput; 115 es->es_if.if_ubareset = enreset; 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)btop(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_if.if_snd.ifq_head == 0) { 255 if (es->es_ifuba.ifu_xtofree) { 256 m_freem(es->es_ifuba.ifu_xtofree); 257 es->es_ifuba.ifu_xtofree = 0; 258 } 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 /* 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 printf("en%d: input error\n", unit); 328 goto setup; 329 } 330 331 /* 332 * Get pointer to ethernet header (in input buffer). 333 * Deal with trailer protocol: if type is PUP trailer 334 * get true type from first 16-bit word past data. 335 * Remember that type was trailer by setting off. 336 */ 337 en = (struct en_header *)(es->es_ifuba.ifu_r.ifrw_addr); 338 #define endataaddr(en, off, type) ((type)(((caddr_t)((en)+1)+(off)))) 339 if (en->en_type >= ENPUP_TRAIL && 340 en->en_type < ENPUP_TRAIL+ENPUP_NTRAILER) { 341 off = (en->en_type - ENPUP_TRAIL) * 512; 342 if (off >= ENMTU) 343 goto setup; /* sanity */ 344 en->en_type = *endataaddr(en, off, u_short *); 345 } else 346 off = 0; 347 348 /* 349 * Attempt to infer packet length from type; 350 * can't deal with packet if can't infer length. 351 */ 352 switch (en->en_type) { 353 354 #ifdef INET 355 case ENPUP_IPTYPE: 356 len = htons((u_short)endataaddr(en, off ? off+2 : 0, struct ip *)->ip_len); 357 if (off) 358 len += 2; 359 setipintr(); 360 inq = &ipintrq; 361 break; 362 #endif 363 364 default: 365 printf("en%d: unknow pkt type 0x%x\n", en->en_type); 366 goto setup; 367 } 368 if (len == 0) 369 goto setup; 370 371 /* 372 * Pull packet off interface. Off is nonzero if packet 373 * has trailing header; if_rubaget will then force this header 374 * information to be at the front, but we still have to drop 375 * the two-byte type which is at the front of any trailer data. 376 */ 377 m = if_rubaget(&es->es_ifuba, len, off); 378 if (m == 0) 379 goto setup; 380 if (off) { 381 m->m_off += 2; 382 m->m_len -= 2; 383 } 384 IF_ENQUEUE(inq, m); 385 386 setup: 387 /* 388 * Reset for next packet. 389 */ 390 addr->en_iba = es->es_ifuba.ifu_r.ifrw_info; 391 addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1; 392 addr->en_istat = EN_IEN|EN_GO; 393 } 394 395 /* 396 * Ethernet output routine. 397 * Encapsulate a packet of type family for the local net. 398 * Use trailer local net encapsulation if enough data in first 399 * packet leaves a multiple of 512 bytes of data in remainder. 400 */ 401 enoutput(ifp, m0, pf) 402 struct ifnet *ifp; 403 struct mbuf *m0; 404 int pf; 405 { 406 int type, dest; 407 register struct mbuf *m = m0; 408 register struct en_header *en; 409 int s; 410 411 switch (pf) { 412 413 #ifdef INET 414 case PF_INET: { 415 register struct ip *ip = mtod(m0, struct ip *); 416 int off; 417 418 #ifndef ENKLUDGE 419 dest = ip->ip_dst.s_addr >> 24; 420 #else 421 dest = (ip->ip_dst.s_addr >> 8) & 0xff; 422 #endif 423 off = ntohs((u_short)ip->ip_len) - m->m_len; 424 if (off > 0 && (off & 0x1ff) == 0 && m->m_off >= MMINOFF + 2) { 425 type = ENPUP_TRAIL + (off>>9); 426 m->m_off -= 2; 427 m->m_len += 2; 428 *mtod(m, u_short *) = ENPUP_IPTYPE; 429 goto gottrailertype; 430 } 431 type = ENPUP_IPTYPE; 432 off = 0; 433 goto gottype; 434 } 435 #endif 436 437 default: 438 printf("en%d: can't encapsulate pf%d\n", ifp->if_unit, pf); 439 m_freem(m0); 440 return (0); 441 } 442 443 gottrailertype: 444 /* 445 * Packet to be sent as trailer: move first packet 446 * (control information) to end of chain. 447 */ 448 while (m->m_next) 449 m = m->m_next; 450 m->m_next = m0; 451 m = m0->m_next; 452 m0->m_next = 0; 453 m0 = m; 454 455 gottype: 456 /* 457 * Add local net header. If no space in first mbuf, 458 * allocate another. 459 */ 460 if (m->m_off > MMAXOFF || 461 MMINOFF + sizeof (struct en_header) > m->m_off) { 462 m = m_get(0); 463 if (m == 0) { 464 m_freem(m0); 465 return (0); 466 } 467 m->m_next = m0; 468 m->m_off = MMINOFF; 469 m->m_len = sizeof (struct en_header); 470 } else { 471 m->m_off -= sizeof (struct en_header); 472 m->m_len += sizeof (struct en_header); 473 } 474 en = mtod(m, struct en_header *); 475 en->en_shost = ifp->if_host[0]; 476 en->en_dhost = dest; 477 en->en_type = type; 478 479 /* 480 * Queue message on interface, and start output if interface 481 * not yet active. 482 */ 483 s = splimp(); 484 IF_ENQUEUE(&ifp->if_snd, m); 485 if (en_softc[ifp->if_unit].es_oactive == 0) 486 enstart(ifp->if_unit); 487 splx(s); 488 return (1); 489 } 490