xref: /csrg-svn/sys/vax/if/if_il.c (revision 12488)
1 /*	if_il.c	4.19	83/05/18	*/
2 
3 #include "il.h"
4 
5 /*
6  * Interlan Ethernet Communications Controller interface
7  */
8 #include "../machine/pte.h"
9 
10 #include "../h/param.h"
11 #include "../h/systm.h"
12 #include "../h/mbuf.h"
13 #include "../h/buf.h"
14 #include "../h/protosw.h"
15 #include "../h/socket.h"
16 #include "../h/vmmac.h"
17 #include <errno.h>
18 
19 #include "../net/if.h"
20 #include "../net/netisr.h"
21 #include "../net/route.h"
22 #include "../netinet/in.h"
23 #include "../netinet/in_systm.h"
24 #include "../netinet/ip.h"
25 #include "../netinet/ip_var.h"
26 #include "../netinet/if_ether.h"
27 #include "../netpup/pup.h"
28 
29 #include "../vax/cpu.h"
30 #include "../vax/mtpr.h"
31 #include "../vaxif/if_il.h"
32 #include "../vaxif/if_ilreg.h"
33 #include "../vaxif/if_uba.h"
34 #include "../vaxuba/ubareg.h"
35 #include "../vaxuba/ubavar.h"
36 
37 int	ilprobe(), ilattach(), ilrint(), ilcint();
38 struct	uba_device *ilinfo[NIL];
39 u_short ilstd[] = { 0 };
40 struct	uba_driver ildriver =
41 	{ ilprobe, 0, ilattach, 0, ilstd, "il", ilinfo };
42 #define	ILUNIT(x)	minor(x)
43 int	ilinit(),iloutput(),ilreset(),ilwatch();
44 
45 /*
46  * Ethernet software status per interface.
47  *
48  * Each interface is referenced by a network interface structure,
49  * is_if, which the routing code uses to locate the interface.
50  * This structure contains the output queue for the interface, its address, ...
51  * We also have, for each interface, a UBA interface structure, which
52  * contains information about the UNIBUS resources held by the interface:
53  * map registers, buffered data paths, etc.  Information is cached in this
54  * structure for use by the if_uba.c routines in running the interface
55  * efficiently.
56  */
57 struct	il_softc {
58 	struct	arpcom is_ac;		/* Ethernet common part */
59 #define	is_if	is_ac.ac_if		/* network-visible interface */
60 #define	is_addr	is_ac.ac_enaddr		/* hardware Ethernet address */
61 	struct	ifuba is_ifuba;		/* UNIBUS resources */
62 	int	is_flags;
63 #define	ILF_OACTIVE	0x1		/* output is active */
64 #define	ILF_RCVPENDING	0x2		/* start rcv in ilcint */
65 #define	ILF_STATPENDING	0x4		/* stat cmd pending */
66 	short	is_lastcmd;		/* can't read csr, so must save it */
67 	short	is_scaninterval;	/* interval of stat collection */
68 #define	ILWATCHINTERVAL	60		/* once every 60 seconds */
69 	struct	il_stats is_stats;	/* holds on-board statistics */
70 	struct	il_stats is_sum;	/* summation over time */
71 	int	is_ubaddr;		/* mapping registers of is_stats */
72 } il_softc[NIL];
73 
74 ilprobe(reg)
75 	caddr_t reg;
76 {
77 	register int br, cvec;		/* r11, r10 value-result */
78 	register struct ildevice *addr = (struct ildevice *)reg;
79 	register i;
80 
81 #ifdef lint
82 	br = 0; cvec = br; br = cvec;
83 	i = 0; ilrint(i); ilcint(i); ilwatch(i);
84 #endif
85 
86 	addr->il_csr = ILC_OFFLINE|IL_CIE;
87 	DELAY(100000);
88 	i = addr->il_csr;		/* clear CDONE */
89 	if (cvec > 0 && cvec != 0x200)
90 		cvec -= 4;
91 	return (1);
92 }
93 
94 /*
95  * Interface exists: make available by filling in network interface
96  * record.  System will initialize the interface when it is ready
97  * to accept packets.  A STATUS command is done to get the ethernet
98  * address and other interesting data.
99  */
100 ilattach(ui)
101 	struct uba_device *ui;
102 {
103 	register struct il_softc *is = &il_softc[ui->ui_unit];
104 	register struct ifnet *ifp = &is->is_if;
105 	register struct ildevice *addr = (struct ildevice *)ui->ui_addr;
106 	struct sockaddr_in *sin;
107 
108 	ifp->if_unit = ui->ui_unit;
109 	ifp->if_name = "il";
110 	ifp->if_mtu = ETHERMTU;
111 
112 	/*
113 	 * Reset the board and map the statistics
114 	 * buffer onto the Unibus.
115 	 */
116 	addr->il_csr = ILC_RESET;
117 	while ((addr->il_csr&IL_CDONE) == 0)
118 		;
119 	if (addr->il_csr&IL_STATUS)
120 		printf("il%d: reset failed, csr=%b\n", ui->ui_unit,
121 			addr->il_csr, IL_BITS);
122 
123 	is->is_ubaddr = uballoc(ui->ui_ubanum, (caddr_t)&is->is_stats,
124 		sizeof (struct il_stats), 0);
125 	addr->il_bar = is->is_ubaddr & 0xffff;
126 	addr->il_bcr = sizeof (struct il_stats);
127 	addr->il_csr = ((is->is_ubaddr >> 2) & IL_EUA)|ILC_STAT;
128 	while ((addr->il_csr&IL_CDONE) == 0)
129 		;
130 	if (addr->il_csr&IL_STATUS)
131 		printf("il%d: status failed, csr=%b\n", ui->ui_unit,
132 			addr->il_csr, IL_BITS);
133 	ubarelse(ui->ui_ubanum, &is->is_ubaddr);
134 #ifdef notdef
135 	printf("il%d: addr=%x:%x:%x:%x:%x:%x module=%s firmware=%s\n",
136 		ui->ui_unit,
137 		is->is_stats.ils_addr[0]&0xff, is->is_stats.ils_addr[1]&0xff,
138 		is->is_stats.ils_addr[2]&0xff, is->is_stats.ils_addr[3]&0xff,
139 		is->is_stats.ils_addr[4]&0xff, is->is_stats.ils_addr[5]&0xff,
140 		is->is_stats.ils_module, is->is_stats.ils_firmware);
141 #endif
142 	bcopy(is->is_stats.ils_addr, is->is_addr, sizeof (is->is_addr));
143 	sin = (struct sockaddr_in *)&ifp->if_addr;
144 	sin->sin_family = AF_INET;
145 	if (ui->ui_flags) {
146 		int i = ((is->is_addr[3]&0xff)<<16) |
147 		    ((is->is_addr[4]&0xff)<<8) |
148 		    (is->is_addr[5]&0xff);
149 		sin->sin_addr = if_makeaddr(ui->ui_flags, i);
150 	} else
151 		sin->sin_addr = arpmyaddr();
152 
153 	ifp->if_init = ilinit;
154 	ifp->if_output = iloutput;
155 	ifp->if_reset = ilreset;
156 	ifp->if_watchdog = ilwatch;
157 	is->is_scaninterval = ILWATCHINTERVAL;
158 	ifp->if_timer = is->is_scaninterval;
159 	is->is_ifuba.ifu_flags = UBA_CANTWAIT;
160 #ifdef notdef
161 	is->is_ifuba.ifu_flags |= UBA_NEEDBDP;
162 #endif
163 	if_attach(ifp);
164 }
165 
166 /*
167  * Reset of interface after UNIBUS reset.
168  * If interface is on specified uba, reset its state.
169  */
170 ilreset(unit, uban)
171 	int unit, uban;
172 {
173 	register struct uba_device *ui;
174 
175 	if (unit >= NIL || (ui = ilinfo[unit]) == 0 || ui->ui_alive == 0 ||
176 	    ui->ui_ubanum != uban)
177 		return;
178 	printf(" il%d", unit);
179 	ilinit(unit);
180 }
181 
182 /*
183  * Initialization of interface; clear recorded pending
184  * operations, and reinitialize UNIBUS usage.
185  */
186 ilinit(unit)
187 	int unit;
188 {
189 	register struct il_softc *is = &il_softc[unit];
190 	register struct uba_device *ui = ilinfo[unit];
191 	register struct ildevice *addr;
192 	int s;
193 	register struct ifnet *ifp = &is->is_if;
194 	register struct sockaddr_in *sin, *sinb;
195 
196 	sin = (struct sockaddr_in *)&ifp->if_addr;
197 	if (sin->sin_addr.s_addr == 0)	/* if address still unknown */
198 		return;
199 	ifp->if_net = in_netof(sin->sin_addr);
200 	ifp->if_host[0] = in_lnaof(sin->sin_addr);
201 	sinb = (struct sockaddr_in *)&ifp->if_broadaddr;
202 	sinb->sin_family = AF_INET;
203 	sinb->sin_addr = if_makeaddr(ifp->if_net, INADDR_ANY);
204 	ifp->if_flags = IFF_BROADCAST;
205 
206 	if (if_ubainit(&is->is_ifuba, ui->ui_ubanum,
207 	    sizeof (struct il_rheader), (int)btoc(ETHERMTU)) == 0) {
208 		printf("il%d: can't initialize\n", unit);
209 		is->is_if.if_flags &= ~IFF_UP;
210 		return;
211 	}
212 	is->is_ubaddr = uballoc(ui->ui_ubanum, (caddr_t)&is->is_stats,
213 		sizeof (struct il_stats), 0);
214 	addr = (struct ildevice *)ui->ui_addr;
215 
216 	/*
217 	 * Turn off source address insertion (it's faster this way),
218 	 * and set board online.  Former doesn't work if board is
219 	 * already online (happens on ubareset), so we put it offline
220 	 * first.
221 	 */
222 	s = splimp();
223 	addr->il_csr = ILC_OFFLINE;
224 	while ((addr->il_csr & IL_CDONE) == 0)
225 		;
226 	addr->il_csr = ILC_CISA;
227 	while ((addr->il_csr & IL_CDONE) == 0)
228 		;
229 	/*
230 	 * Set board online.
231 	 * Hang receive buffer and start any pending
232 	 * writes by faking a transmit complete.
233 	 * Receive bcr is not a muliple of 4 so buffer
234 	 * chaining can't happen.
235 	 */
236 	addr->il_csr = ILC_ONLINE;
237 	while ((addr->il_csr & IL_CDONE) == 0)
238 		;
239 	addr->il_bar = is->is_ifuba.ifu_r.ifrw_info & 0xffff;
240 	addr->il_bcr = sizeof(struct il_rheader) + ETHERMTU + 6;
241 	addr->il_csr =
242 		((is->is_ifuba.ifu_r.ifrw_info >> 2) & IL_EUA)|ILC_RCV|IL_RIE;
243 	while ((addr->il_csr & IL_CDONE) == 0)
244 		;
245 	is->is_flags = ILF_OACTIVE;
246 	is->is_if.if_flags |= IFF_UP;
247 	is->is_lastcmd = 0;
248 	ilcint(unit);
249 	splx(s);
250 	if_rtinit(&is->is_if, RTF_UP);
251 	arpattach(&is->is_ac);
252 	arpwhohas(&is->is_ac, &sin->sin_addr);
253 }
254 
255 /*
256  * Start output on interface.
257  * Get another datagram to send off of the interface queue,
258  * and map it to the interface before starting the output.
259  */
260 ilstart(dev)
261 	dev_t dev;
262 {
263         int unit = ILUNIT(dev), len;
264 	struct uba_device *ui = ilinfo[unit];
265 	register struct il_softc *is = &il_softc[unit];
266 	register struct ildevice *addr;
267 	struct mbuf *m;
268 	short csr;
269 
270 	IF_DEQUEUE(&is->is_if.if_snd, m);
271 	addr = (struct ildevice *)ui->ui_addr;
272 	if (m == 0) {
273 		if ((is->is_flags & ILF_STATPENDING) == 0)
274 			return;
275 		addr->il_bar = is->is_ubaddr & 0xffff;
276 		addr->il_bcr = sizeof (struct il_stats);
277 		csr = ((is->is_ubaddr >> 2) & IL_EUA)|ILC_STAT|IL_RIE|IL_CIE;
278 		is->is_flags &= ~ILF_STATPENDING;
279 		goto startcmd;
280 	}
281 	len = if_wubaput(&is->is_ifuba, m);
282 	/*
283 	 * Ensure minimum packet length.
284 	 * This makes the safe assumtion that there are no virtual holes
285 	 * after the data.
286 	 * For security, it might be wise to zero out the added bytes,
287 	 * but we're mainly interested in speed at the moment.
288 	 */
289 	if (len - sizeof(struct ether_header) < ETHERMIN)
290 		len = ETHERMIN + sizeof(struct ether_header);
291 	if (is->is_ifuba.ifu_flags & UBA_NEEDBDP)
292 		UBAPURGE(is->is_ifuba.ifu_uba, is->is_ifuba.ifu_w.ifrw_bdp);
293 	addr->il_bar = is->is_ifuba.ifu_w.ifrw_info & 0xffff;
294 	addr->il_bcr = len;
295 	csr =
296 	  ((is->is_ifuba.ifu_w.ifrw_info >> 2) & IL_EUA)|ILC_XMIT|IL_CIE|IL_RIE;
297 
298 startcmd:
299 	is->is_lastcmd = csr & IL_CMD;
300 	addr->il_csr = csr;
301 	is->is_flags |= ILF_OACTIVE;
302 }
303 
304 /*
305  * Command done interrupt.
306  */
307 ilcint(unit)
308 	int unit;
309 {
310 	register struct il_softc *is = &il_softc[unit];
311 	struct uba_device *ui = ilinfo[unit];
312 	register struct ildevice *addr = (struct ildevice *)ui->ui_addr;
313 	short csr;
314 
315 	if ((is->is_flags & ILF_OACTIVE) == 0) {
316 		printf("il%d: stray xmit interrupt, csr=%b\n", unit,
317 			addr->il_csr, IL_BITS);
318 		return;
319 	}
320 
321 	csr = addr->il_csr;
322 	/*
323 	 * Hang receive buffer if it couldn't
324 	 * be done earlier (in ilrint).
325 	 */
326 	if (is->is_flags & ILF_RCVPENDING) {
327 		addr->il_bar = is->is_ifuba.ifu_r.ifrw_info & 0xffff;
328 		addr->il_bcr = sizeof(struct il_rheader) + ETHERMTU + 6;
329 		addr->il_csr =
330 		  ((is->is_ifuba.ifu_r.ifrw_info >> 2) & IL_EUA)|ILC_RCV|IL_RIE;
331 		while ((addr->il_csr & IL_CDONE) == 0)
332 			;
333 		is->is_flags &= ~ILF_RCVPENDING;
334 	}
335 	is->is_flags &= ~ILF_OACTIVE;
336 	csr &= IL_STATUS;
337 	switch (is->is_lastcmd) {
338 
339 	case ILC_XMIT:
340 		is->is_if.if_opackets++;
341 		if (csr > ILERR_RETRIES)
342 			is->is_if.if_oerrors++;
343 		break;
344 
345 	case ILC_STAT:
346 		if (csr == ILERR_SUCCESS)
347 			iltotal(is);
348 		break;
349 	}
350 	if (is->is_ifuba.ifu_xtofree) {
351 		m_freem(is->is_ifuba.ifu_xtofree);
352 		is->is_ifuba.ifu_xtofree = 0;
353 	}
354 	ilstart(unit);
355 }
356 
357 /*
358  * Ethernet interface receiver interrupt.
359  * If input error just drop packet.
360  * Otherwise purge input buffered data path and examine
361  * packet to determine type.  If can't determine length
362  * from type, then have to drop packet.  Othewise decapsulate
363  * packet based on type and pass to type specific higher-level
364  * input routine.
365  */
366 ilrint(unit)
367 	int unit;
368 {
369 	register struct il_softc *is = &il_softc[unit];
370 	struct ildevice *addr = (struct ildevice *)ilinfo[unit]->ui_addr;
371 	register struct il_rheader *il;
372     	struct mbuf *m;
373 	int len, off, resid;
374 	register struct ifqueue *inq;
375 
376 	is->is_if.if_ipackets++;
377 	if (is->is_ifuba.ifu_flags & UBA_NEEDBDP)
378 		UBAPURGE(is->is_ifuba.ifu_uba, is->is_ifuba.ifu_r.ifrw_bdp);
379 	il = (struct il_rheader *)(is->is_ifuba.ifu_r.ifrw_addr);
380 	len = il->ilr_length - sizeof(struct il_rheader);
381 	if ((il->ilr_status&(ILFSTAT_A|ILFSTAT_C)) || len < 46 ||
382 	    len > ETHERMTU) {
383 		is->is_if.if_ierrors++;
384 #ifdef notdef
385 		if (is->is_if.if_ierrors % 100 == 0)
386 			printf("il%d: += 100 input errors\n", unit);
387 #endif
388 		goto setup;
389 	}
390 
391 	/*
392 	 * Deal with trailer protocol: if type is PUP trailer
393 	 * get true type from first 16-bit word past data.
394 	 * Remember that type was trailer by setting off.
395 	 */
396 	il->ilr_type = ntohs((u_short)il->ilr_type);
397 #define	ildataaddr(il, off, type)	((type)(((caddr_t)((il)+1)+(off))))
398 	if (il->ilr_type >= ETHERPUP_TRAIL &&
399 	    il->ilr_type < ETHERPUP_TRAIL+ETHERPUP_NTRAILER) {
400 		off = (il->ilr_type - ETHERPUP_TRAIL) * 512;
401 		if (off >= ETHERMTU)
402 			goto setup;		/* sanity */
403 		il->ilr_type = ntohs(*ildataaddr(il, off, u_short *));
404 		resid = ntohs(*(ildataaddr(il, off+2, u_short *)));
405 		if (off + resid > len)
406 			goto setup;		/* sanity */
407 		len = off + resid;
408 	} else
409 		off = 0;
410 	if (len == 0)
411 		goto setup;
412 
413 	/*
414 	 * Pull packet off interface.  Off is nonzero if packet
415 	 * has trailing header; ilget will then force this header
416 	 * information to be at the front, but we still have to drop
417 	 * the type and length which are at the front of any trailer data.
418 	 */
419 	m = if_rubaget(&is->is_ifuba, len, off);
420 	if (m == 0)
421 		goto setup;
422 	if (off) {
423 		m->m_off += 2 * sizeof (u_short);
424 		m->m_len -= 2 * sizeof (u_short);
425 	}
426 	switch (il->ilr_type) {
427 
428 #ifdef INET
429 	case ETHERPUP_IPTYPE:
430 		schednetisr(NETISR_IP);
431 		inq = &ipintrq;
432 		break;
433 
434 	case ETHERPUP_ARPTYPE:
435 		arpinput(&is->is_ac, m);
436 		return;
437 #endif
438 	default:
439 		m_freem(m);
440 		goto setup;
441 	}
442 
443 	if (IF_QFULL(inq)) {
444 		IF_DROP(inq);
445 		m_freem(m);
446 		goto setup;
447 	}
448 	IF_ENQUEUE(inq, m);
449 
450 setup:
451 	/*
452 	 * Reset for next packet if possible.
453 	 * If waiting for transmit command completion, set flag
454 	 * and wait until command completes.
455 	 */
456 	if (is->is_flags & ILF_OACTIVE) {
457 		is->is_flags |= ILF_RCVPENDING;
458 		return;
459 	}
460 	addr->il_bar = is->is_ifuba.ifu_r.ifrw_info & 0xffff;
461 	addr->il_bcr = sizeof(struct il_rheader) + ETHERMTU + 6;
462 	addr->il_csr =
463 		((is->is_ifuba.ifu_r.ifrw_info >> 2) & IL_EUA)|ILC_RCV|IL_RIE;
464 	while ((addr->il_csr & IL_CDONE) == 0)
465 		;
466 }
467 
468 /*
469  * Ethernet output routine.
470  * Encapsulate a packet of type family for the local net.
471  * Use trailer local net encapsulation if enough data in first
472  * packet leaves a multiple of 512 bytes of data in remainder.
473  */
474 iloutput(ifp, m0, dst)
475 	struct ifnet *ifp;
476 	struct mbuf *m0;
477 	struct sockaddr *dst;
478 {
479 	int type, s, error;
480 	u_char edst[6];
481 	struct in_addr idst;
482 	register struct il_softc *is = &il_softc[ifp->if_unit];
483 	register struct mbuf *m = m0;
484 	register struct ether_header *il;
485 	register int off;
486 
487 	switch (dst->sa_family) {
488 
489 #ifdef INET
490 	case AF_INET:
491 		idst = ((struct sockaddr_in *)dst)->sin_addr;
492 		if (!arpresolve(&is->is_ac, m, &idst, edst))
493 			return (0);	/* if not yet resolved */
494 		off = ntohs((u_short)mtod(m, struct ip *)->ip_len) - m->m_len;
495 		if (off > 0 && (off & 0x1ff) == 0 &&
496 		    m->m_off >= MMINOFF + 2 * sizeof (u_short)) {
497 			type = ETHERPUP_TRAIL + (off>>9);
498 			m->m_off -= 2 * sizeof (u_short);
499 			m->m_len += 2 * sizeof (u_short);
500 			*mtod(m, u_short *) = htons((u_short)ETHERPUP_IPTYPE);
501 			*(mtod(m, u_short *) + 1) = htons((u_short)m->m_len);
502 			goto gottrailertype;
503 		}
504 		type = ETHERPUP_IPTYPE;
505 		off = 0;
506 		goto gottype;
507 #endif
508 
509 	case AF_UNSPEC:
510 		il = (struct ether_header *)dst->sa_data;
511 		bcopy(il->ether_dhost, edst, sizeof (edst));
512 		type = il->ether_type;
513 		goto gottype;
514 
515 	default:
516 		printf("il%d: can't handle af%d\n", ifp->if_unit,
517 			dst->sa_family);
518 		error = EAFNOSUPPORT;
519 		goto bad;
520 	}
521 
522 gottrailertype:
523 	/*
524 	 * Packet to be sent as trailer: move first packet
525 	 * (control information) to end of chain.
526 	 */
527 	while (m->m_next)
528 		m = m->m_next;
529 	m->m_next = m0;
530 	m = m0->m_next;
531 	m0->m_next = 0;
532 	m0 = m;
533 
534 gottype:
535 	/*
536 	 * Add local net header.  If no space in first mbuf,
537 	 * allocate another.
538 	 */
539 	if (m->m_off > MMAXOFF ||
540 	    MMINOFF + sizeof (struct ether_header) > m->m_off) {
541 		m = m_get(M_DONTWAIT, MT_HEADER);
542 		if (m == 0) {
543 			error = ENOBUFS;
544 			goto bad;
545 		}
546 		m->m_next = m0;
547 		m->m_off = MMINOFF;
548 		m->m_len = sizeof (struct ether_header);
549 	} else {
550 		m->m_off -= sizeof (struct ether_header);
551 		m->m_len += sizeof (struct ether_header);
552 	}
553 	il = mtod(m, struct ether_header *);
554 	il->ether_type = htons((u_short)type);
555 	bcopy(edst, il->ether_dhost, sizeof (edst));
556 	bcopy((caddr_t)is->is_addr, (caddr_t)il->ether_shost, 6);
557 
558 	/*
559 	 * Queue message on interface, and start output if interface
560 	 * not yet active.
561 	 */
562 	s = splimp();
563 	if (IF_QFULL(&ifp->if_snd)) {
564 		IF_DROP(&ifp->if_snd);
565 		splx(s);
566 		m_freem(m);
567 		return (ENOBUFS);
568 	}
569 	IF_ENQUEUE(&ifp->if_snd, m);
570 	if ((is->is_flags & ILF_OACTIVE) == 0)
571 		ilstart(ifp->if_unit);
572 	splx(s);
573 	return (0);
574 
575 bad:
576 	m_freem(m0);
577 	return (error);
578 }
579 
580 /*
581  * Watchdog routine, request statistics from board.
582  */
583 ilwatch(unit)
584 	int unit;
585 {
586 	register struct il_softc *is = &il_softc[unit];
587 	register struct ifnet *ifp = &is->is_if;
588 	int s;
589 
590 	if (is->is_flags & ILF_STATPENDING) {
591 		ifp->if_timer = is->is_scaninterval;
592 		return;
593 	}
594 	s = splimp();
595 	is->is_flags |= ILF_STATPENDING;
596 	if ((is->is_flags & ILF_OACTIVE) == 0)
597 		ilstart(ifp->if_unit);
598 	splx(s);
599 	ifp->if_timer = is->is_scaninterval;
600 }
601 
602 /*
603  * Total up the on-board statistics.
604  */
605 iltotal(is)
606 	register struct il_softc *is;
607 {
608 	register u_short *interval, *sum, *end;
609 
610 	interval = &is->is_stats.ils_frames;
611 	sum = &is->is_sum.ils_frames;
612 	end = is->is_sum.ils_fill2;
613 	while (sum < end)
614 		*sum++ += *interval++;
615 	is->is_if.if_collisions = is->is_sum.ils_collis;
616 }
617