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5073ce2e | 1 | /* |
ad787160 C |
2 | * Copyright (c) 1992, 1993 |
3 | * The Regents of the University of California. All rights reserved. | |
5073ce2e CT |
4 | * |
5 | * This software was developed by the Computer Systems Engineering group | |
6 | * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and | |
7 | * contributed to Berkeley. | |
8 | * | |
9 | * All advertising materials mentioning features or use of this software | |
10 | * must display the following acknowledgement: | |
11 | * This product includes software developed by the University of | |
12 | * California, Lawrence Berkeley Laboratories. | |
13 | * | |
ad787160 C |
14 | * Redistribution and use in source and binary forms, with or without |
15 | * modification, are permitted provided that the following conditions | |
16 | * are met: | |
17 | * 1. Redistributions of source code must retain the above copyright | |
18 | * notice, this list of conditions and the following disclaimer. | |
19 | * 2. Redistributions in binary form must reproduce the above copyright | |
20 | * notice, this list of conditions and the following disclaimer in the | |
21 | * documentation and/or other materials provided with the distribution. | |
22 | * 3. All advertising materials mentioning features or use of this software | |
23 | * must display the following acknowledgement: | |
24 | * This product includes software developed by the University of | |
25 | * California, Berkeley and its contributors. | |
26 | * 4. Neither the name of the University nor the names of its contributors | |
27 | * may be used to endorse or promote products derived from this software | |
28 | * without specific prior written permission. | |
29 | * | |
30 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
31 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
32 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
33 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
34 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
35 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
36 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
37 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
38 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
39 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
40 | * SUCH DAMAGE. | |
5073ce2e | 41 | * |
ad787160 | 42 | * @(#)pack.c 8.1 (Berkeley) 6/6/93 |
5073ce2e CT |
43 | */ |
44 | ||
45 | #include <sys/param.h> | |
46 | #include <stdlib.h> | |
47 | #include <string.h> | |
48 | #include "config.h" | |
49 | ||
50 | /* | |
51 | * Packing. We have three separate kinds of packing here. | |
52 | * | |
53 | * First, we pack device instances, to collapse things like | |
54 | * | |
55 | * uba0 at sbi0 nexus ? | |
56 | * uba0 at bi0 nexus ? | |
57 | * | |
58 | * into a single instance that is "at sbi0 or bi0". | |
59 | * | |
60 | * Second, we pack locators. Given something like | |
61 | * | |
62 | * hp0 at mba0 drive 0 | |
63 | * hp* at mba* drive ? | |
64 | * ht0 at mba0 drive 0 | |
65 | * tu0 at ht0 slave 0 | |
66 | * ht* at mba* drive ? | |
67 | * tu* at ht* slave ? | |
68 | * | |
69 | * (where the default drive and slave numbers are -1), we have three | |
70 | * locators whose value is 0 and three whose value is -1. Rather than | |
71 | * emitting six integers, we emit just two. | |
72 | * | |
73 | * Finally, we pack parent vectors. This is very much like packing | |
74 | * locators. Unlike locators, however, parent vectors are always | |
75 | * terminated by -1 (rather like the way C strings always end with | |
76 | * a NUL). | |
77 | * | |
78 | * When packing locators, we would like to find sequences such as | |
79 | * {1 2 3} {2 3 4} {3} {4 5} | |
80 | * and turn this into the flat sequence {1 2 3 4 5}, with each subsequence | |
81 | * given by the appropriate offset (here 0, 1, 2, and 3 respectively). | |
82 | * When we pack parent vectors, overlap of this sort is impossible. | |
83 | * Non-overlapping packing is much easier, and so we use that here | |
84 | * and miss out on the chance to squeeze the locator sequence optimally. | |
85 | * (So it goes.) | |
86 | */ | |
87 | ||
88 | typedef int (*vec_cmp_func) __P((const void *, int, int)); | |
89 | ||
90 | #define TAILHSIZE 128 | |
91 | #define PVHASH(i) ((i) & (TAILHSIZE - 1)) | |
92 | #define LOCHASH(l) (((int)(l) >> 2) & (TAILHSIZE - 1)) | |
93 | struct tails { | |
94 | struct tails *t_next; | |
95 | int t_ends_at; | |
96 | }; | |
97 | ||
98 | static struct tails *tails[TAILHSIZE]; | |
99 | static int locspace; | |
100 | static int pvecspace; | |
101 | static int longest_pvec; | |
102 | ||
103 | static void packdevi __P((void)); | |
104 | static void packlocs __P((void)); | |
105 | static void packpvec __P((void)); | |
106 | ||
107 | static void addparents __P((struct devi *src, struct devi *dst)); | |
108 | static int nparents __P((struct devi **, struct devbase *, int)); | |
109 | static int sameas __P((struct devi *, struct devi *)); | |
110 | static int findvec __P((const void *, int, int, vec_cmp_func, int)); | |
111 | static int samelocs __P((const void *, int, int)); | |
112 | static int addlocs __P((const char **, int)); | |
113 | static int loclencmp __P((const void *, const void *)); | |
114 | static int samepv __P((const void *, int, int)); | |
115 | static int addpv __P((short *, int)); | |
116 | static int pvlencmp __P((const void *, const void *)); | |
117 | static void resettails __P((void)); | |
118 | ||
119 | void | |
120 | pack() | |
121 | { | |
122 | register struct devi *i; | |
123 | register int n; | |
124 | ||
125 | /* Pack instances and make parent vectors. */ | |
126 | packdevi(); | |
127 | ||
128 | /* | |
129 | * Now that we know what we have, find upper limits on space | |
130 | * needed for the loc[] and pv[] tables, and find the longest | |
131 | * single pvec. The loc and pv table sizes are bounded by | |
132 | * what we would get if no packing occurred. | |
133 | */ | |
134 | locspace = pvecspace = 0; | |
135 | for (i = alldevi; i != NULL; i = i->i_next) { | |
136 | if (i->i_collapsed) | |
137 | continue; | |
138 | locspace += i->i_atattr->a_loclen; | |
139 | n = i->i_pvlen + 1; | |
140 | if (n > longest_pvec) | |
141 | longest_pvec = n; | |
142 | pvecspace += n; | |
143 | } | |
144 | ||
145 | /* Allocate and pack loc[]. */ | |
146 | locators.vec = emalloc(locspace * sizeof(*locators.vec)); | |
147 | locators.used = 0; | |
148 | packlocs(); | |
149 | ||
150 | /* Allocate and pack pv[]. */ | |
151 | parents.vec = emalloc(pvecspace * sizeof(*parents.vec)); | |
152 | parents.used = 0; | |
153 | packpvec(); | |
154 | } | |
155 | ||
156 | /* | |
157 | * Pack instances together wherever possible. When everything is | |
158 | * packed, go back and set up the parents for each. We must do this | |
159 | * on a second pass because during the first one, we do not know which, | |
160 | * if any, of the parents will collapse during packing. | |
161 | */ | |
162 | void | |
163 | packdevi() | |
164 | { | |
165 | register struct devi *i, *l, *p; | |
166 | register struct devbase *d; | |
167 | register int j, m, n; | |
168 | ||
169 | packed = emalloc((ndevi + 1) * sizeof *packed); | |
170 | n = 0; | |
171 | for (d = allbases; d != NULL; d = d->d_next) { | |
172 | /* | |
173 | * For each instance of each device, add or collapse | |
174 | * all its aliases. | |
175 | */ | |
176 | for (i = d->d_ihead; i != NULL; i = i->i_bsame) { | |
177 | m = n; | |
178 | for (l = i; l != NULL; l = l->i_alias) { | |
179 | l->i_pvlen = 0; | |
180 | l->i_pvoff = -1; | |
181 | l->i_locoff = -1; | |
182 | l->i_ivoff = -1; | |
183 | /* try to find an equivalent for l */ | |
184 | for (j = m; j < n; j++) { | |
185 | p = packed[j]; | |
186 | if (sameas(l, p)) { | |
187 | l->i_collapsed = 1; | |
188 | l->i_cfindex = p->i_cfindex; | |
189 | goto nextalias; | |
190 | } | |
191 | } | |
192 | /* could not find a suitable alias */ | |
193 | l->i_collapsed = 0; | |
194 | l->i_cfindex = n; | |
195 | l->i_parents = emalloc(sizeof(*l->i_parents)); | |
196 | l->i_parents[0] = NULL; | |
197 | packed[n++] = l; | |
198 | nextalias:; | |
199 | } | |
200 | } | |
201 | } | |
202 | npacked = n; | |
203 | packed[n] = NULL; | |
204 | for (i = alldevi; i != NULL; i = i->i_next) | |
205 | addparents(i, packed[i->i_cfindex]); | |
206 | } | |
207 | ||
208 | /* | |
209 | * Return true if two aliases are "the same". In this case, they need | |
210 | * to have the same config flags and the same locators. | |
211 | */ | |
212 | static int | |
213 | sameas(i1, i2) | |
214 | register struct devi *i1, *i2; | |
215 | { | |
216 | register const char **p1, **p2; | |
217 | ||
218 | if (i1->i_cfflags != i2->i_cfflags) | |
219 | return (0); | |
220 | for (p1 = i1->i_locs, p2 = i2->i_locs; *p1 == *p2; p2++) | |
221 | if (*p1++ == 0) | |
222 | return (1); | |
223 | return 0; | |
224 | } | |
225 | ||
226 | /* | |
227 | * Add the parents associated with "src" to the (presumably uncollapsed) | |
228 | * instance "dst". | |
229 | */ | |
230 | static void | |
231 | addparents(src, dst) | |
232 | register struct devi *src, *dst; | |
233 | { | |
234 | register struct nvlist *nv; | |
235 | register struct devi *i, **p, **q; | |
236 | register int j, n, old, new, ndup; | |
237 | ||
238 | if (dst->i_collapsed) | |
239 | panic("addparents() i_collapsed"); | |
240 | ||
241 | /* Collect up list of parents to add. */ | |
242 | if (src->i_at == NULL) /* none, 'cuz "at root" */ | |
243 | return; | |
244 | if (src->i_atdev != NULL) { | |
245 | n = nparents(NULL, src->i_atdev, src->i_atunit); | |
246 | p = emalloc(n * sizeof *p); | |
247 | if (n == 0) | |
248 | return; | |
249 | (void)nparents(p, src->i_atdev, src->i_atunit); | |
250 | } else { | |
251 | n = 0; | |
252 | for (nv = src->i_atattr->a_refs; nv != NULL; nv = nv->nv_next) | |
253 | n += nparents(NULL, nv->nv_ptr, src->i_atunit); | |
254 | if (n == 0) | |
255 | return; | |
256 | p = emalloc(n * sizeof *p); | |
257 | n = 0; | |
258 | for (nv = src->i_atattr->a_refs; nv != NULL; nv = nv->nv_next) | |
259 | n += nparents(p + n, nv->nv_ptr, src->i_atunit); | |
260 | } | |
261 | /* Now elide duplicates. */ | |
262 | ndup = 0; | |
263 | for (j = 0; j < n; j++) { | |
264 | i = p[j]; | |
265 | for (q = dst->i_parents; *q != NULL; q++) { | |
266 | if (*q == i) { | |
267 | ndup++; | |
268 | p[j] = NULL; | |
269 | break; | |
270 | } | |
271 | } | |
272 | } | |
273 | /* Finally, add all the non-duplicates. */ | |
274 | old = dst->i_pvlen; | |
275 | new = old + (n - ndup); | |
276 | if (old > new) | |
277 | panic("addparents() old > new"); | |
278 | if (old == new) { | |
279 | free(p); | |
280 | return; | |
281 | } | |
282 | dst->i_parents = q = erealloc(dst->i_parents, (new + 1) * sizeof(*q)); | |
283 | dst->i_pvlen = new; | |
284 | q[new] = NULL; | |
285 | q += old; | |
286 | for (j = 0; j < n; j++) | |
287 | if (p[j] != NULL) | |
288 | *q++ = p[j]; | |
289 | free(p); | |
290 | } | |
291 | ||
292 | /* | |
293 | * Count up parents, and optionally store pointers to each. | |
294 | */ | |
295 | static int | |
296 | nparents(p, dev, unit) | |
297 | register struct devi **p; | |
298 | register struct devbase *dev; | |
299 | register int unit; | |
300 | { | |
301 | register struct devi *i, *l; | |
302 | register int n; | |
303 | ||
304 | n = 0; | |
305 | /* for each instance ... */ | |
306 | for (i = dev->d_ihead; i != NULL; i = i->i_bsame) { | |
307 | /* ... take each un-collapsed alias */ | |
308 | for (l = i; l != NULL; l = l->i_alias) { | |
309 | if (!l->i_collapsed && | |
310 | (unit == WILD || unit == l->i_unit)) { | |
311 | if (p != NULL) | |
312 | *p++ = l; | |
313 | n++; | |
314 | } | |
315 | } | |
316 | } | |
317 | return (n); | |
318 | } | |
319 | ||
320 | static void | |
321 | packlocs() | |
322 | { | |
323 | register struct devi **p, *i; | |
324 | register int l, o; | |
325 | ||
326 | qsort(packed, npacked, sizeof *packed, loclencmp); | |
327 | for (p = packed; (i = *p) != NULL; p++) { | |
328 | if ((l = i->i_atattr->a_loclen) > 0) { | |
329 | o = findvec(i->i_locs, LOCHASH(i->i_locs[l - 1]), l, | |
330 | samelocs, locators.used); | |
331 | i->i_locoff = o < 0 ? addlocs(i->i_locs, l) : o; | |
332 | } else | |
333 | i->i_locoff = -1; | |
334 | } | |
335 | resettails(); | |
336 | } | |
337 | ||
338 | static void | |
339 | packpvec() | |
340 | { | |
341 | register struct devi **p, *i, **par; | |
342 | register int l, v, o; | |
343 | register short *vec; | |
344 | ||
345 | vec = emalloc(longest_pvec * sizeof(*vec)); | |
346 | qsort(packed, npacked, sizeof *packed, pvlencmp); | |
347 | for (p = packed; (i = *p) != NULL; p++) { | |
348 | l = i->i_pvlen; | |
349 | if (l > longest_pvec) panic("packpvec"); | |
350 | par = i->i_parents; | |
351 | for (v = 0; v < l; v++) | |
352 | vec[v] = par[v]->i_cfindex; | |
353 | if (l == 0 || | |
354 | (o = findvec(vec, PVHASH(vec[l - 1]), l, | |
355 | samepv, parents.used)) < 0) | |
356 | o = addpv(vec, l); | |
357 | i->i_pvoff = o; | |
358 | } | |
359 | free(vec); | |
360 | resettails(); | |
361 | } | |
362 | ||
363 | /* | |
364 | * Return the index at which the given vector already exists, or -1 | |
365 | * if it is not anywhere in the current set. If we return -1, we assume | |
366 | * our caller will add it at the end of the current set, and we make | |
367 | * sure that next time, we will find it there. | |
368 | */ | |
369 | static int | |
370 | findvec(ptr, hash, len, cmp, nextplace) | |
371 | const void *ptr; | |
372 | int hash, len; | |
373 | vec_cmp_func cmp; | |
374 | int nextplace; | |
375 | { | |
376 | register struct tails *t, **hp; | |
377 | register int off; | |
378 | ||
379 | hp = &tails[hash]; | |
380 | for (t = *hp; t != NULL; t = t->t_next) { | |
381 | off = t->t_ends_at - len; | |
382 | if (off >= 0 && (*cmp)(ptr, off, len)) | |
383 | return (off); | |
384 | } | |
385 | t = emalloc(sizeof(*t)); | |
386 | t->t_next = *hp; | |
387 | *hp = t; | |
388 | t->t_ends_at = nextplace + len; | |
389 | return (-1); | |
390 | } | |
391 | ||
392 | /* | |
393 | * Comparison function for locators. | |
394 | */ | |
395 | static int | |
396 | samelocs(ptr, off, len) | |
397 | const void *ptr; | |
398 | int off; | |
399 | register int len; | |
400 | { | |
401 | register const char **p, **q; | |
402 | ||
403 | for (p = &locators.vec[off], q = (const char **)ptr; --len >= 0;) | |
404 | if (*p++ != *q++) | |
405 | return (0); /* different */ | |
406 | return (1); /* same */ | |
407 | } | |
408 | ||
409 | /* | |
410 | * Add the given locators at the end of the global loc[] table. | |
411 | */ | |
412 | static int | |
413 | addlocs(locs, len) | |
414 | register const char **locs; | |
415 | register int len; | |
416 | { | |
417 | register const char **p; | |
418 | register int ret; | |
419 | ||
420 | ret = locators.used; | |
421 | if ((locators.used = ret + len) > locspace) | |
422 | panic("addlocs: overrun"); | |
423 | for (p = &locators.vec[ret]; --len >= 0;) | |
424 | *p++ = *locs++; | |
425 | return (ret); | |
426 | } | |
427 | ||
428 | /* | |
429 | * Comparison function for qsort-by-locator-length, longest first. | |
430 | * We rashly assume that subtraction of these lengths does not overflow. | |
431 | */ | |
432 | static int | |
433 | loclencmp(a, b) | |
434 | const void *a, *b; | |
435 | { | |
436 | register int l1, l2; | |
437 | ||
438 | l1 = (*(struct devi **)a)->i_atattr->a_loclen; | |
439 | l2 = (*(struct devi **)b)->i_atattr->a_loclen; | |
440 | return (l2 - l1); | |
441 | } | |
442 | ||
443 | /* | |
444 | * Comparison function for parent vectors. | |
445 | */ | |
446 | static int | |
447 | samepv(ptr, off, len) | |
448 | const void *ptr; | |
449 | int off; | |
450 | register int len; | |
451 | { | |
452 | register short *p, *q; | |
453 | ||
454 | for (p = &parents.vec[off], q = (short *)ptr; --len >= 0;) | |
455 | if (*p++ != *q++) | |
456 | return (0); /* different */ | |
457 | return (1); /* same */ | |
458 | } | |
459 | ||
460 | /* | |
461 | * Add the given parent vectors at the end of the global pv[] table. | |
462 | */ | |
463 | static int | |
464 | addpv(pv, len) | |
465 | register short *pv; | |
466 | register int len; | |
467 | { | |
468 | register short *p; | |
469 | register int ret; | |
470 | static int firstend = -1; | |
471 | ||
472 | /* | |
473 | * If the vector is empty, reuse the first -1. It will be | |
474 | * there if there are any nonempty vectors at all, since we | |
475 | * do the longest first. If there are no nonempty vectors, | |
476 | * something is probably wrong, but we will ignore that here. | |
477 | */ | |
478 | if (len == 0 && firstend >= 0) | |
479 | return (firstend); | |
480 | len++; /* account for trailing -1 */ | |
481 | ret = parents.used; | |
482 | if ((parents.used = ret + len) > pvecspace) | |
483 | panic("addpv: overrun"); | |
484 | for (p = &parents.vec[ret]; --len > 0;) | |
485 | *p++ = *pv++; | |
486 | *p = -1; | |
487 | if (firstend < 0) | |
488 | firstend = parents.used - 1; | |
489 | return (ret); | |
490 | } | |
491 | ||
492 | /* | |
493 | * Comparison function for qsort-by-parent-vector-length, longest first. | |
494 | * We rashly assume that subtraction of these lengths does not overflow. | |
495 | */ | |
496 | static int | |
497 | pvlencmp(a, b) | |
498 | const void *a, *b; | |
499 | { | |
500 | register int l1, l2; | |
501 | ||
502 | l1 = (*(struct devi **)a)->i_pvlen; | |
503 | l2 = (*(struct devi **)b)->i_pvlen; | |
504 | return (l2 - l1); | |
505 | } | |
506 | ||
507 | static void | |
508 | resettails() | |
509 | { | |
510 | register struct tails **p, *t, *next; | |
511 | register int i; | |
512 | ||
513 | for (p = tails, i = TAILHSIZE; --i >= 0; p++) { | |
514 | for (t = *p; t != NULL; t = next) { | |
515 | next = t->t_next; | |
516 | free(t); | |
517 | } | |
518 | *p = NULL; | |
519 | } | |
520 | } |