1 /* if_en.c 4.15 81/11/29 */ 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 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, "es", 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; 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_mtu = ENMTU; 100 es->es_if.if_net = ui->ui_flags; 101 es->es_if.if_host[0] = 102 ~(((struct endevice *)eninfo[ui->ui_unit])->en_addr) & 0xff; 103 es->es_if.if_addr = 104 if_makeaddr(es->es_if.if_net, es->es_if.if_host[0]); 105 es->es_if.if_output = enoutput; 106 es->es_if.if_init = eninit; 107 es->es_if.if_ubareset = enreset; 108 } 109 110 /* 111 * Reset of interface after UNIBUS reset. 112 * If interface is on specified uba, reset its state. 113 */ 114 enreset(unit, uban) 115 int unit, uban; 116 { 117 register struct uba_device *ui; 118 COUNT(ENRESET); 119 120 if (unit >= NEN || (ui = eninfo[unit]) == 0 || ui->ui_alive == 0) { 121 printf("es%d: not alive\n", unit); 122 return; 123 } 124 if (ui->ui_ubanum != uban) 125 return; 126 eninit(unit); 127 } 128 129 /* 130 * Initialization of interface; clear recorded pending 131 * operations, and reinitialize UNIBUS usage. 132 */ 133 eninit(unit) 134 int unit; 135 { 136 register struct uba_device *ui; 137 register struct endevice *addr; 138 register struct en_softc *es; 139 int s; 140 141 es = &en_softc[unit]; 142 ui = eninfo[unit]; 143 if (if_ubainit(&es->es_ifuba, ui->ui_ubanum, 144 sizeof (struct en_header), (int)btop(ENMTU)) == 0) { 145 printf("es%d: can't initialize\n", unit); 146 return; 147 } 148 addr = (struct endevice *)ui->ui_addr; 149 addr->en_istat = addr->en_ostat = 0; 150 151 /* 152 * Hang pending read, start any writes. 153 */ 154 s = splimp(); 155 enstart(unit); 156 enxint(unit); 157 splx(s); 158 } 159 160 int enlastdel = 25; 161 162 /* 163 * Start or restart output on interface. 164 * If interface is already active, then this is a retransmit 165 * after a collision, and just restuff registers and delay. 166 * If interface is not already active, get another datagram 167 * to send off of the interface queue, and map it to the interface 168 * before starting the output. 169 */ 170 enstart(dev) 171 dev_t dev; 172 { 173 int unit; 174 struct uba_device *ui; 175 register struct endevice *addr; 176 register struct en_softc *es; 177 struct mbuf *m; 178 int dest; 179 COUNT(ENSTART); 180 181 unit = ENUNIT(dev); 182 ui = eninfo[unit]; 183 es = &en_softc[unit]; 184 if (es->es_oactive) 185 goto restart; 186 187 /* 188 * Not already active: dequeue another request 189 * and map it to the UNIBUS. If no more requests, 190 * just return. 191 */ 192 IF_DEQUEUE(&es->es_if.if_snd, m); 193 if (m == 0) { 194 es->es_oactive = 0; 195 return; 196 } 197 es->es_olen = if_wubaput(&es->es_ifuba, m); 198 199 /* 200 * Ethernet cannot take back-to-back packets (no 201 * buffering in interface. To avoid overrunning 202 * receiver, enforce a small delay (about 1ms) in interface 203 * on successive packets sent to same host. 204 */ 205 dest = mtod(m, struct en_header *)->en_dhost; 206 if (es->es_lastx && es->es_lastx == dest) 207 es->es_delay = enlastdel; 208 else 209 es->es_lastx = dest; 210 211 restart: 212 /* 213 * Have request mapped to UNIBUS for transmission. 214 * Purge any stale data from this BDP, and start the otput. 215 */ 216 UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_w.ifrw_bdp); 217 addr = (struct endevice *)ui->ui_addr; 218 addr->en_oba = (int)es->es_ifuba.ifu_w.ifrw_addr; 219 addr->en_odelay = es->es_delay; 220 addr->en_owc = -((es->es_olen + 1) >> 1); 221 addr->en_ostat = EN_IEN|EN_GO; 222 es->es_oactive = 1; 223 } 224 225 /* 226 * Ethernet interface transmitter interrupt. 227 * Start another output if more data to send. 228 */ 229 enxint(unit) 230 int unit; 231 { 232 register struct endevice *addr; 233 register struct uba_device *ui; 234 register struct en_softc *es; 235 COUNT(ENXINT); 236 237 ui = eninfo[unit]; 238 es = &en_softc[unit]; 239 if (es->es_oactive == 0) 240 return; 241 addr = (struct endevice *)ui->ui_addr; 242 es = &en_softc[unit]; 243 es->es_oactive = 0; 244 es->es_delay = 0; 245 es->es_mask = ~0; 246 if (addr->en_ostat&EN_OERROR) 247 printf("es%d: output error\n", unit); 248 if (es->es_if.if_snd.ifq_head == 0) { 249 es->es_lastx = 0; 250 return; 251 } 252 enstart(unit); 253 } 254 255 /* 256 * Collision on ethernet interface. Do exponential 257 * backoff, and retransmit. If have backed off all 258 * the way printing warning diagnostic, and drop packet. 259 */ 260 encollide(unit) 261 int unit; 262 { 263 register struct en_softc *es; 264 COUNT(ENCOLLIDE); 265 266 es = &en_softc[unit]; 267 es->es_if.if_collisions++; 268 if (es->es_oactive == 0) 269 return; 270 if (es->es_mask == 0) { 271 printf("es%d: send error\n", unit); 272 enxint(unit); 273 } else { 274 es->es_mask <<= 1; 275 es->es_delay = mfpr(ICR) &~ es->es_mask; 276 enstart(unit); 277 } 278 } 279 280 /* 281 * Ethernet interface receiver interrupt. 282 * If input error just drop packet. 283 * Otherwise purge input buffered data path and examine 284 * packet to determine type. If can't determine length 285 * from type, then have to drop packet. Othewise decapsulate 286 * packet based on type and pass to type specific higher-level 287 * input routine. 288 */ 289 enrint(unit) 290 int unit; 291 { 292 struct endevice *addr; 293 register struct en_softc *es; 294 struct en_header *en; 295 struct mbuf *m; 296 struct ifqueue *inq; 297 register int len; 298 int off; 299 COUNT(ENRINT); 300 301 es = &en_softc[unit]; 302 addr = (struct endevice *)eninfo[unit]->ui_addr; 303 304 /* 305 * Purge BDP; drop error packets. 306 */ 307 UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_r.ifrw_bdp); 308 if (addr->en_istat&EN_IERROR) { 309 es->es_if.if_ierrors++; 310 printf("es%d: input error\n", unit); 311 goto setup; 312 } 313 314 /* 315 * Get pointer to ethernet header (in input buffer). 316 * Deal with trailer protocol: if type is PUP trailer 317 * get true type from first 16-bit word past data. 318 * Remember that type was trailer by setting off. 319 */ 320 en = (struct en_header *)(es->es_ifuba.ifu_r.ifrw_addr); 321 #define endataaddr(en, off, type) ((type)(((caddr_t)((en)+1)+(off)))) 322 if (en->en_type >= ENPUP_TRAIL && 323 en->en_type < ENPUP_TRAIL+ENPUP_NTRAILER) { 324 off = (en->en_type - ENPUP_TRAIL) * 512; 325 en->en_type = *endataaddr(en, off, u_short *); 326 off += 2; 327 } else 328 off = 0; 329 330 /* 331 * Attempt to infer packet length from type; 332 * can't deal with packet if can't infer length. 333 */ 334 switch (en->en_type) { 335 336 #ifdef INET 337 case ENPUP_IPTYPE: 338 len = endataaddr(en, off, struct ip *)->ip_len; 339 setipintr(); 340 inq = &ipintrq; 341 break; 342 #endif 343 344 default: 345 printf("en%d: unknow pkt type 0x%x\n", en->en_type); 346 goto setup; 347 } 348 if (len == 0) 349 goto setup; 350 351 /* 352 * Pull packet off interface. Off is nonzero if packet 353 * has trailing header; if_rubaget will then force this header 354 * information to be at the front, but we still have to drop 355 * the two-byte type which is at the front of the trailer data 356 * (which we ``consumed'' above). 357 */ 358 m = if_rubaget(&es->es_ifuba, len, off); 359 if (off) { 360 m->m_off += 2; 361 m->m_len -= 2; 362 } 363 IF_ENQUEUE(inq, m); 364 365 setup: 366 /* 367 * Reset for next packet. 368 */ 369 addr->en_iba = es->es_ifuba.ifu_r.ifrw_info; 370 addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1; 371 addr->en_istat = EN_IEN|EN_GO; 372 } 373 374 /* 375 * Ethernet output routine. 376 * Encapsulate a packet of type family for the local net. 377 * Use trailer local net encapsulation if enough data in first 378 * packet leaves a multiple of 512 bytes of data in remainder. 379 */ 380 enoutput(ifp, m0, pf) 381 struct ifnet *ifp; 382 struct mbuf *m0; 383 int pf; 384 { 385 int type, dest; 386 register struct mbuf *m = m0; 387 register struct en_header *en; 388 int s; 389 390 switch (pf) { 391 392 #ifdef INET 393 case PF_INET: { 394 register struct ip *ip = mtod(m0, struct ip *); 395 int off; 396 397 dest = ip->ip_dst.s_addr >> 24; 398 off = ip->ip_len - m->m_len; 399 if (off && off % 512 == 0 && m->m_off >= MMINOFF + 2) { 400 type = ENPUP_TRAIL + (off>>9); 401 m->m_off -= 2; 402 m->m_len += 2; 403 *mtod(m, u_short *) = ENPUP_IPTYPE; 404 goto gottrailertype; 405 } 406 type = ENPUP_IPTYPE; 407 off = 0; 408 goto gottype; 409 } 410 #endif 411 412 default: 413 printf("en%d: can't encapsulate pf%d\n", ifp->if_unit, pf); 414 m_freem(m0); 415 return (0); 416 } 417 418 /* 419 * Packet to be sent as trailer: move first packet 420 * (control information) to end of chain. 421 */ 422 gottrailertype: 423 while (m->m_next) 424 m = m->m_next; 425 m->m_next = m0; 426 m = m0->m_next; 427 m0->m_next = 0; 428 429 /* 430 * Add local net header. If no space in first mbuf, 431 * allocate another. 432 */ 433 gottype: 434 m0 = m; 435 if (MMINOFF + sizeof (struct en_header) > m->m_off) { 436 m = m_get(0); 437 if (m == 0) { 438 m_freem(m0); 439 return (0); 440 } 441 m->m_next = m0; 442 m->m_off = MMINOFF; 443 m->m_len = sizeof (struct en_header); 444 } else { 445 m = m0; 446 m->m_off -= sizeof (struct en_header); 447 m->m_len += sizeof (struct en_header); 448 } 449 en = mtod(m, struct en_header *); 450 en->en_shost = ifp->if_host[0]; 451 en->en_dhost = dest; 452 en->en_type = type; 453 454 /* 455 * Queue message on interface, and start output if interface 456 * not yet active. 457 */ 458 s = splimp(); 459 IF_ENQUEUE(&ifp->if_snd, m); 460 splx(s); 461 if (en_softc[ifp->if_unit].es_oactive == 0) 462 enstart(ifp->if_unit); 463 return (1); 464 } 465