FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_rman.c
1 /*-
2 * Copyright 1998 Massachusetts Institute of Technology
3 *
4 * Permission to use, copy, modify, and distribute this software and
5 * its documentation for any purpose and without fee is hereby
6 * granted, provided that both the above copyright notice and this
7 * permission notice appear in all copies, that both the above
8 * copyright notice and this permission notice appear in all
9 * supporting documentation, and that the name of M.I.T. not be used
10 * in advertising or publicity pertaining to distribution of the
11 * software without specific, written prior permission. M.I.T. makes
12 * no representations about the suitability of this software for any
13 * purpose. It is provided "as is" without express or implied
14 * warranty.
15 *
16 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
17 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
20 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
23 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 /*
31 * The kernel resource manager. This code is responsible for keeping track
32 * of hardware resources which are apportioned out to various drivers.
33 * It does not actually assign those resources, and it is not expected
34 * that end-device drivers will call into this code directly. Rather,
35 * the code which implements the buses that those devices are attached to,
36 * and the code which manages CPU resources, will call this code, and the
37 * end-device drivers will make upcalls to that code to actually perform
38 * the allocation.
39 *
40 * There are two sorts of resources managed by this code. The first is
41 * the more familiar array (RMAN_ARRAY) type; resources in this class
42 * consist of a sequence of individually-allocatable objects which have
43 * been numbered in some well-defined order. Most of the resources
44 * are of this type, as it is the most familiar. The second type is
45 * called a gauge (RMAN_GAUGE), and models fungible resources (i.e.,
46 * resources in which each instance is indistinguishable from every
47 * other instance). The principal anticipated application of gauges
48 * is in the context of power consumption, where a bus may have a specific
49 * power budget which all attached devices share. RMAN_GAUGE is not
50 * implemented yet.
51 *
52 * For array resources, we make one simplifying assumption: two clients
53 * sharing the same resource must use the same range of indices. That
54 * is to say, sharing of overlapping-but-not-identical regions is not
55 * permitted.
56 */
57
58 #include "opt_ddb.h"
59
60 #include <sys/cdefs.h>
61 __FBSDID("$FreeBSD: releng/8.4/sys/kern/subr_rman.c 223501 2011-06-24 13:45:14Z jhb $");
62
63 #include <sys/param.h>
64 #include <sys/systm.h>
65 #include <sys/kernel.h>
66 #include <sys/limits.h>
67 #include <sys/lock.h>
68 #include <sys/malloc.h>
69 #include <sys/mutex.h>
70 #include <sys/bus.h> /* XXX debugging */
71 #include <machine/bus.h>
72 #include <sys/rman.h>
73 #include <sys/sysctl.h>
74
75 #ifdef DDB
76 #include <ddb/ddb.h>
77 #endif
78
79 /*
80 * We use a linked list rather than a bitmap because we need to be able to
81 * represent potentially huge objects (like all of a processor's physical
82 * address space). That is also why the indices are defined to have type
83 * `unsigned long' -- that being the largest integral type in ISO C (1990).
84 * The 1999 version of C allows `long long'; we may need to switch to that
85 * at some point in the future, particularly if we want to support 36-bit
86 * addresses on IA32 hardware.
87 */
88 struct resource_i {
89 struct resource r_r;
90 TAILQ_ENTRY(resource_i) r_link;
91 LIST_ENTRY(resource_i) r_sharelink;
92 LIST_HEAD(, resource_i) *r_sharehead;
93 u_long r_start; /* index of the first entry in this resource */
94 u_long r_end; /* index of the last entry (inclusive) */
95 u_int r_flags;
96 void *r_virtual; /* virtual address of this resource */
97 struct device *r_dev; /* device which has allocated this resource */
98 struct rman *r_rm; /* resource manager from whence this came */
99 int r_rid; /* optional rid for this resource. */
100 };
101
102 static int rman_debug = 0;
103 TUNABLE_INT("debug.rman_debug", &rman_debug);
104 SYSCTL_INT(_debug, OID_AUTO, rman_debug, CTLFLAG_RW,
105 &rman_debug, 0, "rman debug");
106
107 #define DPRINTF(params) if (rman_debug) printf params
108
109 static MALLOC_DEFINE(M_RMAN, "rman", "Resource manager");
110
111 struct rman_head rman_head;
112 static struct mtx rman_mtx; /* mutex to protect rman_head */
113 static int int_rman_activate_resource(struct rman *rm, struct resource_i *r,
114 struct resource_i **whohas);
115 static int int_rman_deactivate_resource(struct resource_i *r);
116 static int int_rman_release_resource(struct rman *rm, struct resource_i *r);
117
118 static __inline struct resource_i *
119 int_alloc_resource(int malloc_flag)
120 {
121 struct resource_i *r;
122
123 r = malloc(sizeof *r, M_RMAN, malloc_flag | M_ZERO);
124 if (r != NULL) {
125 r->r_r.__r_i = r;
126 }
127 return (r);
128 }
129
130 int
131 rman_init(struct rman *rm)
132 {
133 static int once = 0;
134
135 if (once == 0) {
136 once = 1;
137 TAILQ_INIT(&rman_head);
138 mtx_init(&rman_mtx, "rman head", NULL, MTX_DEF);
139 }
140
141 if (rm->rm_start == 0 && rm->rm_end == 0)
142 rm->rm_end = ~0ul;
143 if (rm->rm_type == RMAN_UNINIT)
144 panic("rman_init");
145 if (rm->rm_type == RMAN_GAUGE)
146 panic("implement RMAN_GAUGE");
147
148 TAILQ_INIT(&rm->rm_list);
149 rm->rm_mtx = malloc(sizeof *rm->rm_mtx, M_RMAN, M_NOWAIT | M_ZERO);
150 if (rm->rm_mtx == NULL)
151 return ENOMEM;
152 mtx_init(rm->rm_mtx, "rman", NULL, MTX_DEF);
153
154 mtx_lock(&rman_mtx);
155 TAILQ_INSERT_TAIL(&rman_head, rm, rm_link);
156 mtx_unlock(&rman_mtx);
157 return 0;
158 }
159
160 int
161 rman_manage_region(struct rman *rm, u_long start, u_long end)
162 {
163 struct resource_i *r, *s, *t;
164
165 DPRINTF(("rman_manage_region: <%s> request: start %#lx, end %#lx\n",
166 rm->rm_descr, start, end));
167 if (start < rm->rm_start || end > rm->rm_end)
168 return EINVAL;
169 r = int_alloc_resource(M_NOWAIT);
170 if (r == NULL)
171 return ENOMEM;
172 r->r_start = start;
173 r->r_end = end;
174 r->r_rm = rm;
175
176 mtx_lock(rm->rm_mtx);
177
178 /* Skip entries before us. */
179 TAILQ_FOREACH(s, &rm->rm_list, r_link) {
180 if (s->r_end == ULONG_MAX)
181 break;
182 if (s->r_end + 1 >= r->r_start)
183 break;
184 }
185
186 /* If we ran off the end of the list, insert at the tail. */
187 if (s == NULL) {
188 TAILQ_INSERT_TAIL(&rm->rm_list, r, r_link);
189 } else {
190 /* Check for any overlap with the current region. */
191 if (r->r_start <= s->r_end && r->r_end >= s->r_start)
192 return EBUSY;
193
194 /* Check for any overlap with the next region. */
195 t = TAILQ_NEXT(s, r_link);
196 if (t && r->r_start <= t->r_end && r->r_end >= t->r_start)
197 return EBUSY;
198
199 /*
200 * See if this region can be merged with the next region. If
201 * not, clear the pointer.
202 */
203 if (t && (r->r_end + 1 != t->r_start || t->r_flags != 0))
204 t = NULL;
205
206 /* See if we can merge with the current region. */
207 if (s->r_end + 1 == r->r_start && s->r_flags == 0) {
208 /* Can we merge all 3 regions? */
209 if (t != NULL) {
210 s->r_end = t->r_end;
211 TAILQ_REMOVE(&rm->rm_list, t, r_link);
212 free(r, M_RMAN);
213 free(t, M_RMAN);
214 } else {
215 s->r_end = r->r_end;
216 free(r, M_RMAN);
217 }
218 } else if (t != NULL) {
219 /* Can we merge with just the next region? */
220 t->r_start = r->r_start;
221 free(r, M_RMAN);
222 } else if (s->r_end < r->r_start) {
223 TAILQ_INSERT_AFTER(&rm->rm_list, s, r, r_link);
224 } else {
225 TAILQ_INSERT_BEFORE(s, r, r_link);
226 }
227 }
228
229 mtx_unlock(rm->rm_mtx);
230 return 0;
231 }
232
233 int
234 rman_init_from_resource(struct rman *rm, struct resource *r)
235 {
236 int rv;
237
238 if ((rv = rman_init(rm)) != 0)
239 return (rv);
240 return (rman_manage_region(rm, r->__r_i->r_start, r->__r_i->r_end));
241 }
242
243 int
244 rman_fini(struct rman *rm)
245 {
246 struct resource_i *r;
247
248 mtx_lock(rm->rm_mtx);
249 TAILQ_FOREACH(r, &rm->rm_list, r_link) {
250 if (r->r_flags & RF_ALLOCATED) {
251 mtx_unlock(rm->rm_mtx);
252 return EBUSY;
253 }
254 }
255
256 /*
257 * There really should only be one of these if we are in this
258 * state and the code is working properly, but it can't hurt.
259 */
260 while (!TAILQ_EMPTY(&rm->rm_list)) {
261 r = TAILQ_FIRST(&rm->rm_list);
262 TAILQ_REMOVE(&rm->rm_list, r, r_link);
263 free(r, M_RMAN);
264 }
265 mtx_unlock(rm->rm_mtx);
266 mtx_lock(&rman_mtx);
267 TAILQ_REMOVE(&rman_head, rm, rm_link);
268 mtx_unlock(&rman_mtx);
269 mtx_destroy(rm->rm_mtx);
270 free(rm->rm_mtx, M_RMAN);
271
272 return 0;
273 }
274
275 int
276 rman_first_free_region(struct rman *rm, u_long *start, u_long *end)
277 {
278 struct resource_i *r;
279
280 mtx_lock(rm->rm_mtx);
281 TAILQ_FOREACH(r, &rm->rm_list, r_link) {
282 if (!(r->r_flags & RF_ALLOCATED)) {
283 *start = r->r_start;
284 *end = r->r_end;
285 mtx_unlock(rm->rm_mtx);
286 return (0);
287 }
288 }
289 mtx_unlock(rm->rm_mtx);
290 return (ENOENT);
291 }
292
293 int
294 rman_last_free_region(struct rman *rm, u_long *start, u_long *end)
295 {
296 struct resource_i *r;
297
298 mtx_lock(rm->rm_mtx);
299 TAILQ_FOREACH_REVERSE(r, &rm->rm_list, resource_head, r_link) {
300 if (!(r->r_flags & RF_ALLOCATED)) {
301 *start = r->r_start;
302 *end = r->r_end;
303 mtx_unlock(rm->rm_mtx);
304 return (0);
305 }
306 }
307 mtx_unlock(rm->rm_mtx);
308 return (ENOENT);
309 }
310
311 /* Shrink or extend one or both ends of an allocated resource. */
312 int
313 rman_adjust_resource(struct resource *rr, u_long start, u_long end)
314 {
315 struct resource_i *r, *s, *t, *new;
316 struct rman *rm;
317
318 /* Not supported for shared resources. */
319 r = rr->__r_i;
320 if (r->r_flags & (RF_TIMESHARE | RF_SHAREABLE))
321 return (EINVAL);
322
323 /*
324 * This does not support wholesale moving of a resource. At
325 * least part of the desired new range must overlap with the
326 * existing resource.
327 */
328 if (end < r->r_start || r->r_end < start)
329 return (EINVAL);
330
331 /*
332 * Find the two resource regions immediately adjacent to the
333 * allocated resource.
334 */
335 rm = r->r_rm;
336 mtx_lock(rm->rm_mtx);
337 #ifdef INVARIANTS
338 TAILQ_FOREACH(s, &rm->rm_list, r_link) {
339 if (s == r)
340 break;
341 }
342 if (s == NULL)
343 panic("resource not in list");
344 #endif
345 s = TAILQ_PREV(r, resource_head, r_link);
346 t = TAILQ_NEXT(r, r_link);
347 KASSERT(s == NULL || s->r_end + 1 == r->r_start,
348 ("prev resource mismatch"));
349 KASSERT(t == NULL || r->r_end + 1 == t->r_start,
350 ("next resource mismatch"));
351
352 /*
353 * See if the changes are permitted. Shrinking is always allowed,
354 * but growing requires sufficient room in the adjacent region.
355 */
356 if (start < r->r_start && (s == NULL || (s->r_flags & RF_ALLOCATED) ||
357 s->r_start > start)) {
358 mtx_unlock(rm->rm_mtx);
359 return (EBUSY);
360 }
361 if (end > r->r_end && (t == NULL || (t->r_flags & RF_ALLOCATED) ||
362 t->r_end < end)) {
363 mtx_unlock(rm->rm_mtx);
364 return (EBUSY);
365 }
366
367 /*
368 * While holding the lock, grow either end of the resource as
369 * needed and shrink either end if the shrinking does not require
370 * allocating a new resource. We can safely drop the lock and then
371 * insert a new range to handle the shrinking case afterwards.
372 */
373 if (start < r->r_start ||
374 (start > r->r_start && s != NULL && !(s->r_flags & RF_ALLOCATED))) {
375 KASSERT(s->r_flags == 0, ("prev is busy"));
376 r->r_start = start;
377 if (s->r_start == start) {
378 TAILQ_REMOVE(&rm->rm_list, s, r_link);
379 free(s, M_RMAN);
380 } else
381 s->r_end = start - 1;
382 }
383 if (end > r->r_end ||
384 (end < r->r_end && t != NULL && !(t->r_flags & RF_ALLOCATED))) {
385 KASSERT(t->r_flags == 0, ("next is busy"));
386 r->r_end = end;
387 if (t->r_end == end) {
388 TAILQ_REMOVE(&rm->rm_list, t, r_link);
389 free(t, M_RMAN);
390 } else
391 t->r_start = end + 1;
392 }
393 mtx_unlock(rm->rm_mtx);
394
395 /*
396 * Handle the shrinking cases that require allocating a new
397 * resource to hold the newly-free region. We have to recheck
398 * if we still need this new region after acquiring the lock.
399 */
400 if (start > r->r_start) {
401 new = int_alloc_resource(M_WAITOK);
402 new->r_start = r->r_start;
403 new->r_end = start - 1;
404 new->r_rm = rm;
405 mtx_lock(rm->rm_mtx);
406 r->r_start = start;
407 s = TAILQ_PREV(r, resource_head, r_link);
408 if (s != NULL && !(s->r_flags & RF_ALLOCATED)) {
409 s->r_end = start - 1;
410 free(new, M_RMAN);
411 } else
412 TAILQ_INSERT_BEFORE(r, new, r_link);
413 mtx_unlock(rm->rm_mtx);
414 }
415 if (end < r->r_end) {
416 new = int_alloc_resource(M_WAITOK);
417 new->r_start = end + 1;
418 new->r_end = r->r_end;
419 new->r_rm = rm;
420 mtx_lock(rm->rm_mtx);
421 r->r_end = end;
422 t = TAILQ_NEXT(r, r_link);
423 if (t != NULL && !(t->r_flags & RF_ALLOCATED)) {
424 t->r_start = end + 1;
425 free(new, M_RMAN);
426 } else
427 TAILQ_INSERT_AFTER(&rm->rm_list, r, new, r_link);
428 mtx_unlock(rm->rm_mtx);
429 }
430 return (0);
431 }
432
433 struct resource *
434 rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end,
435 u_long count, u_long bound, u_int flags,
436 struct device *dev)
437 {
438 u_int want_activate;
439 struct resource_i *r, *s, *rv;
440 u_long rstart, rend, amask, bmask;
441
442 rv = NULL;
443
444 DPRINTF(("rman_reserve_resource_bound: <%s> request: [%#lx, %#lx], "
445 "length %#lx, flags %u, device %s\n", rm->rm_descr, start, end,
446 count, flags,
447 dev == NULL ? "<null>" : device_get_nameunit(dev)));
448 want_activate = (flags & RF_ACTIVE);
449 flags &= ~RF_ACTIVE;
450
451 mtx_lock(rm->rm_mtx);
452
453 for (r = TAILQ_FIRST(&rm->rm_list);
454 r && r->r_end < start;
455 r = TAILQ_NEXT(r, r_link))
456 ;
457
458 if (r == NULL) {
459 DPRINTF(("could not find a region\n"));
460 goto out;
461 }
462
463 amask = (1ul << RF_ALIGNMENT(flags)) - 1;
464 /* If bound is 0, bmask will also be 0 */
465 bmask = ~(bound - 1);
466 /*
467 * First try to find an acceptable totally-unshared region.
468 */
469 for (s = r; s; s = TAILQ_NEXT(s, r_link)) {
470 DPRINTF(("considering [%#lx, %#lx]\n", s->r_start, s->r_end));
471 if (s->r_start + count - 1 > end) {
472 DPRINTF(("s->r_start (%#lx) + count - 1> end (%#lx)\n",
473 s->r_start, end));
474 break;
475 }
476 if (s->r_flags & RF_ALLOCATED) {
477 DPRINTF(("region is allocated\n"));
478 continue;
479 }
480 rstart = ulmax(s->r_start, start);
481 /*
482 * Try to find a region by adjusting to boundary and alignment
483 * until both conditions are satisfied. This is not an optimal
484 * algorithm, but in most cases it isn't really bad, either.
485 */
486 do {
487 rstart = (rstart + amask) & ~amask;
488 if (((rstart ^ (rstart + count - 1)) & bmask) != 0)
489 rstart += bound - (rstart & ~bmask);
490 } while ((rstart & amask) != 0 && rstart < end &&
491 rstart < s->r_end);
492 rend = ulmin(s->r_end, ulmax(rstart + count - 1, end));
493 if (rstart > rend) {
494 DPRINTF(("adjusted start exceeds end\n"));
495 continue;
496 }
497 DPRINTF(("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n",
498 rstart, rend, (rend - rstart + 1), count));
499
500 if ((rend - rstart + 1) >= count) {
501 DPRINTF(("candidate region: [%#lx, %#lx], size %#lx\n",
502 rstart, rend, (rend - rstart + 1)));
503 if ((s->r_end - s->r_start + 1) == count) {
504 DPRINTF(("candidate region is entire chunk\n"));
505 rv = s;
506 rv->r_flags |= RF_ALLOCATED | flags;
507 rv->r_dev = dev;
508 goto out;
509 }
510
511 /*
512 * If s->r_start < rstart and
513 * s->r_end > rstart + count - 1, then
514 * we need to split the region into three pieces
515 * (the middle one will get returned to the user).
516 * Otherwise, we are allocating at either the
517 * beginning or the end of s, so we only need to
518 * split it in two. The first case requires
519 * two new allocations; the second requires but one.
520 */
521 rv = int_alloc_resource(M_NOWAIT);
522 if (rv == NULL)
523 goto out;
524 rv->r_start = rstart;
525 rv->r_end = rstart + count - 1;
526 rv->r_flags = flags | RF_ALLOCATED;
527 rv->r_dev = dev;
528 rv->r_rm = rm;
529
530 if (s->r_start < rv->r_start && s->r_end > rv->r_end) {
531 DPRINTF(("splitting region in three parts: "
532 "[%#lx, %#lx]; [%#lx, %#lx]; [%#lx, %#lx]\n",
533 s->r_start, rv->r_start - 1,
534 rv->r_start, rv->r_end,
535 rv->r_end + 1, s->r_end));
536 /*
537 * We are allocating in the middle.
538 */
539 r = int_alloc_resource(M_NOWAIT);
540 if (r == NULL) {
541 free(rv, M_RMAN);
542 rv = NULL;
543 goto out;
544 }
545 r->r_start = rv->r_end + 1;
546 r->r_end = s->r_end;
547 r->r_flags = s->r_flags;
548 r->r_rm = rm;
549 s->r_end = rv->r_start - 1;
550 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv,
551 r_link);
552 TAILQ_INSERT_AFTER(&rm->rm_list, rv, r,
553 r_link);
554 } else if (s->r_start == rv->r_start) {
555 DPRINTF(("allocating from the beginning\n"));
556 /*
557 * We are allocating at the beginning.
558 */
559 s->r_start = rv->r_end + 1;
560 TAILQ_INSERT_BEFORE(s, rv, r_link);
561 } else {
562 DPRINTF(("allocating at the end\n"));
563 /*
564 * We are allocating at the end.
565 */
566 s->r_end = rv->r_start - 1;
567 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv,
568 r_link);
569 }
570 goto out;
571 }
572 }
573
574 /*
575 * Now find an acceptable shared region, if the client's requirements
576 * allow sharing. By our implementation restriction, a candidate
577 * region must match exactly by both size and sharing type in order
578 * to be considered compatible with the client's request. (The
579 * former restriction could probably be lifted without too much
580 * additional work, but this does not seem warranted.)
581 */
582 DPRINTF(("no unshared regions found\n"));
583 if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0)
584 goto out;
585
586 for (s = r; s; s = TAILQ_NEXT(s, r_link)) {
587 if (s->r_start > end)
588 break;
589 if ((s->r_flags & flags) != flags)
590 continue;
591 rstart = ulmax(s->r_start, start);
592 rend = ulmin(s->r_end, ulmax(start + count - 1, end));
593 if (s->r_start >= start && s->r_end <= end
594 && (s->r_end - s->r_start + 1) == count &&
595 (s->r_start & amask) == 0 &&
596 ((s->r_start ^ s->r_end) & bmask) == 0) {
597 rv = int_alloc_resource(M_NOWAIT);
598 if (rv == NULL)
599 goto out;
600 rv->r_start = s->r_start;
601 rv->r_end = s->r_end;
602 rv->r_flags = s->r_flags &
603 (RF_ALLOCATED | RF_SHAREABLE | RF_TIMESHARE);
604 rv->r_dev = dev;
605 rv->r_rm = rm;
606 if (s->r_sharehead == NULL) {
607 s->r_sharehead = malloc(sizeof *s->r_sharehead,
608 M_RMAN, M_NOWAIT | M_ZERO);
609 if (s->r_sharehead == NULL) {
610 free(rv, M_RMAN);
611 rv = NULL;
612 goto out;
613 }
614 LIST_INIT(s->r_sharehead);
615 LIST_INSERT_HEAD(s->r_sharehead, s,
616 r_sharelink);
617 s->r_flags |= RF_FIRSTSHARE;
618 }
619 rv->r_sharehead = s->r_sharehead;
620 LIST_INSERT_HEAD(s->r_sharehead, rv, r_sharelink);
621 goto out;
622 }
623 }
624
625 /*
626 * We couldn't find anything.
627 */
628 out:
629 /*
630 * If the user specified RF_ACTIVE in the initial flags,
631 * which is reflected in `want_activate', we attempt to atomically
632 * activate the resource. If this fails, we release the resource
633 * and indicate overall failure. (This behavior probably doesn't
634 * make sense for RF_TIMESHARE-type resources.)
635 */
636 if (rv && want_activate) {
637 struct resource_i *whohas;
638 if (int_rman_activate_resource(rm, rv, &whohas)) {
639 int_rman_release_resource(rm, rv);
640 rv = NULL;
641 }
642 }
643
644 mtx_unlock(rm->rm_mtx);
645 return (rv == NULL ? NULL : &rv->r_r);
646 }
647
648 struct resource *
649 rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
650 u_int flags, struct device *dev)
651 {
652
653 return (rman_reserve_resource_bound(rm, start, end, count, 0, flags,
654 dev));
655 }
656
657 static int
658 int_rman_activate_resource(struct rman *rm, struct resource_i *r,
659 struct resource_i **whohas)
660 {
661 struct resource_i *s;
662 int ok;
663
664 /*
665 * If we are not timesharing, then there is nothing much to do.
666 * If we already have the resource, then there is nothing at all to do.
667 * If we are not on a sharing list with anybody else, then there is
668 * little to do.
669 */
670 if ((r->r_flags & RF_TIMESHARE) == 0
671 || (r->r_flags & RF_ACTIVE) != 0
672 || r->r_sharehead == NULL) {
673 r->r_flags |= RF_ACTIVE;
674 return 0;
675 }
676
677 ok = 1;
678 for (s = LIST_FIRST(r->r_sharehead); s && ok;
679 s = LIST_NEXT(s, r_sharelink)) {
680 if ((s->r_flags & RF_ACTIVE) != 0) {
681 ok = 0;
682 *whohas = s;
683 }
684 }
685 if (ok) {
686 r->r_flags |= RF_ACTIVE;
687 return 0;
688 }
689 return EBUSY;
690 }
691
692 int
693 rman_activate_resource(struct resource *re)
694 {
695 int rv;
696 struct resource_i *r, *whohas;
697 struct rman *rm;
698
699 r = re->__r_i;
700 rm = r->r_rm;
701 mtx_lock(rm->rm_mtx);
702 rv = int_rman_activate_resource(rm, r, &whohas);
703 mtx_unlock(rm->rm_mtx);
704 return rv;
705 }
706
707 int
708 rman_await_resource(struct resource *re, int pri, int timo)
709 {
710 int rv;
711 struct resource_i *r, *whohas;
712 struct rman *rm;
713
714 r = re->__r_i;
715 rm = r->r_rm;
716 mtx_lock(rm->rm_mtx);
717 for (;;) {
718 rv = int_rman_activate_resource(rm, r, &whohas);
719 if (rv != EBUSY)
720 return (rv); /* returns with mutex held */
721
722 if (r->r_sharehead == NULL)
723 panic("rman_await_resource");
724 whohas->r_flags |= RF_WANTED;
725 rv = msleep(r->r_sharehead, rm->rm_mtx, pri, "rmwait", timo);
726 if (rv) {
727 mtx_unlock(rm->rm_mtx);
728 return (rv);
729 }
730 }
731 }
732
733 static int
734 int_rman_deactivate_resource(struct resource_i *r)
735 {
736
737 r->r_flags &= ~RF_ACTIVE;
738 if (r->r_flags & RF_WANTED) {
739 r->r_flags &= ~RF_WANTED;
740 wakeup(r->r_sharehead);
741 }
742 return 0;
743 }
744
745 int
746 rman_deactivate_resource(struct resource *r)
747 {
748 struct rman *rm;
749
750 rm = r->__r_i->r_rm;
751 mtx_lock(rm->rm_mtx);
752 int_rman_deactivate_resource(r->__r_i);
753 mtx_unlock(rm->rm_mtx);
754 return 0;
755 }
756
757 static int
758 int_rman_release_resource(struct rman *rm, struct resource_i *r)
759 {
760 struct resource_i *s, *t;
761
762 if (r->r_flags & RF_ACTIVE)
763 int_rman_deactivate_resource(r);
764
765 /*
766 * Check for a sharing list first. If there is one, then we don't
767 * have to think as hard.
768 */
769 if (r->r_sharehead) {
770 /*
771 * If a sharing list exists, then we know there are at
772 * least two sharers.
773 *
774 * If we are in the main circleq, appoint someone else.
775 */
776 LIST_REMOVE(r, r_sharelink);
777 s = LIST_FIRST(r->r_sharehead);
778 if (r->r_flags & RF_FIRSTSHARE) {
779 s->r_flags |= RF_FIRSTSHARE;
780 TAILQ_INSERT_BEFORE(r, s, r_link);
781 TAILQ_REMOVE(&rm->rm_list, r, r_link);
782 }
783
784 /*
785 * Make sure that the sharing list goes away completely
786 * if the resource is no longer being shared at all.
787 */
788 if (LIST_NEXT(s, r_sharelink) == NULL) {
789 free(s->r_sharehead, M_RMAN);
790 s->r_sharehead = NULL;
791 s->r_flags &= ~RF_FIRSTSHARE;
792 }
793 goto out;
794 }
795
796 /*
797 * Look at the adjacent resources in the list and see if our
798 * segment can be merged with any of them. If either of the
799 * resources is allocated or is not exactly adjacent then they
800 * cannot be merged with our segment.
801 */
802 s = TAILQ_PREV(r, resource_head, r_link);
803 if (s != NULL && ((s->r_flags & RF_ALLOCATED) != 0 ||
804 s->r_end + 1 != r->r_start))
805 s = NULL;
806 t = TAILQ_NEXT(r, r_link);
807 if (t != NULL && ((t->r_flags & RF_ALLOCATED) != 0 ||
808 r->r_end + 1 != t->r_start))
809 t = NULL;
810
811 if (s != NULL && t != NULL) {
812 /*
813 * Merge all three segments.
814 */
815 s->r_end = t->r_end;
816 TAILQ_REMOVE(&rm->rm_list, r, r_link);
817 TAILQ_REMOVE(&rm->rm_list, t, r_link);
818 free(t, M_RMAN);
819 } else if (s != NULL) {
820 /*
821 * Merge previous segment with ours.
822 */
823 s->r_end = r->r_end;
824 TAILQ_REMOVE(&rm->rm_list, r, r_link);
825 } else if (t != NULL) {
826 /*
827 * Merge next segment with ours.
828 */
829 t->r_start = r->r_start;
830 TAILQ_REMOVE(&rm->rm_list, r, r_link);
831 } else {
832 /*
833 * At this point, we know there is nothing we
834 * can potentially merge with, because on each
835 * side, there is either nothing there or what is
836 * there is still allocated. In that case, we don't
837 * want to remove r from the list; we simply want to
838 * change it to an unallocated region and return
839 * without freeing anything.
840 */
841 r->r_flags &= ~RF_ALLOCATED;
842 r->r_dev = NULL;
843 return 0;
844 }
845
846 out:
847 free(r, M_RMAN);
848 return 0;
849 }
850
851 int
852 rman_release_resource(struct resource *re)
853 {
854 int rv;
855 struct resource_i *r;
856 struct rman *rm;
857
858 r = re->__r_i;
859 rm = r->r_rm;
860 mtx_lock(rm->rm_mtx);
861 rv = int_rman_release_resource(rm, r);
862 mtx_unlock(rm->rm_mtx);
863 return (rv);
864 }
865
866 uint32_t
867 rman_make_alignment_flags(uint32_t size)
868 {
869 int i;
870
871 /*
872 * Find the hightest bit set, and add one if more than one bit
873 * set. We're effectively computing the ceil(log2(size)) here.
874 */
875 for (i = 31; i > 0; i--)
876 if ((1 << i) & size)
877 break;
878 if (~(1 << i) & size)
879 i++;
880
881 return(RF_ALIGNMENT_LOG2(i));
882 }
883
884 void
885 rman_set_start(struct resource *r, u_long start)
886 {
887 r->__r_i->r_start = start;
888 }
889
890 u_long
891 rman_get_start(struct resource *r)
892 {
893 return (r->__r_i->r_start);
894 }
895
896 void
897 rman_set_end(struct resource *r, u_long end)
898 {
899 r->__r_i->r_end = end;
900 }
901
902 u_long
903 rman_get_end(struct resource *r)
904 {
905 return (r->__r_i->r_end);
906 }
907
908 u_long
909 rman_get_size(struct resource *r)
910 {
911 return (r->__r_i->r_end - r->__r_i->r_start + 1);
912 }
913
914 u_int
915 rman_get_flags(struct resource *r)
916 {
917 return (r->__r_i->r_flags);
918 }
919
920 void
921 rman_set_virtual(struct resource *r, void *v)
922 {
923 r->__r_i->r_virtual = v;
924 }
925
926 void *
927 rman_get_virtual(struct resource *r)
928 {
929 return (r->__r_i->r_virtual);
930 }
931
932 void
933 rman_set_bustag(struct resource *r, bus_space_tag_t t)
934 {
935 r->r_bustag = t;
936 }
937
938 bus_space_tag_t
939 rman_get_bustag(struct resource *r)
940 {
941 return (r->r_bustag);
942 }
943
944 void
945 rman_set_bushandle(struct resource *r, bus_space_handle_t h)
946 {
947 r->r_bushandle = h;
948 }
949
950 bus_space_handle_t
951 rman_get_bushandle(struct resource *r)
952 {
953 return (r->r_bushandle);
954 }
955
956 void
957 rman_set_rid(struct resource *r, int rid)
958 {
959 r->__r_i->r_rid = rid;
960 }
961
962 int
963 rman_get_rid(struct resource *r)
964 {
965 return (r->__r_i->r_rid);
966 }
967
968 void
969 rman_set_device(struct resource *r, struct device *dev)
970 {
971 r->__r_i->r_dev = dev;
972 }
973
974 struct device *
975 rman_get_device(struct resource *r)
976 {
977 return (r->__r_i->r_dev);
978 }
979
980 int
981 rman_is_region_manager(struct resource *r, struct rman *rm)
982 {
983
984 return (r->__r_i->r_rm == rm);
985 }
986
987 /*
988 * Sysctl interface for scanning the resource lists.
989 *
990 * We take two input parameters; the index into the list of resource
991 * managers, and the resource offset into the list.
992 */
993 static int
994 sysctl_rman(SYSCTL_HANDLER_ARGS)
995 {
996 int *name = (int *)arg1;
997 u_int namelen = arg2;
998 int rman_idx, res_idx;
999 struct rman *rm;
1000 struct resource_i *res;
1001 struct resource_i *sres;
1002 struct u_rman urm;
1003 struct u_resource ures;
1004 int error;
1005
1006 if (namelen != 3)
1007 return (EINVAL);
1008
1009 if (bus_data_generation_check(name[0]))
1010 return (EINVAL);
1011 rman_idx = name[1];
1012 res_idx = name[2];
1013
1014 /*
1015 * Find the indexed resource manager
1016 */
1017 mtx_lock(&rman_mtx);
1018 TAILQ_FOREACH(rm, &rman_head, rm_link) {
1019 if (rman_idx-- == 0)
1020 break;
1021 }
1022 mtx_unlock(&rman_mtx);
1023 if (rm == NULL)
1024 return (ENOENT);
1025
1026 /*
1027 * If the resource index is -1, we want details on the
1028 * resource manager.
1029 */
1030 if (res_idx == -1) {
1031 bzero(&urm, sizeof(urm));
1032 urm.rm_handle = (uintptr_t)rm;
1033 if (rm->rm_descr != NULL)
1034 strlcpy(urm.rm_descr, rm->rm_descr, RM_TEXTLEN);
1035 urm.rm_start = rm->rm_start;
1036 urm.rm_size = rm->rm_end - rm->rm_start + 1;
1037 urm.rm_type = rm->rm_type;
1038
1039 error = SYSCTL_OUT(req, &urm, sizeof(urm));
1040 return (error);
1041 }
1042
1043 /*
1044 * Find the indexed resource and return it.
1045 */
1046 mtx_lock(rm->rm_mtx);
1047 TAILQ_FOREACH(res, &rm->rm_list, r_link) {
1048 if (res->r_sharehead != NULL) {
1049 LIST_FOREACH(sres, res->r_sharehead, r_sharelink)
1050 if (res_idx-- == 0) {
1051 res = sres;
1052 goto found;
1053 }
1054 }
1055 else if (res_idx-- == 0)
1056 goto found;
1057 }
1058 mtx_unlock(rm->rm_mtx);
1059 return (ENOENT);
1060
1061 found:
1062 bzero(&ures, sizeof(ures));
1063 ures.r_handle = (uintptr_t)res;
1064 ures.r_parent = (uintptr_t)res->r_rm;
1065 ures.r_device = (uintptr_t)res->r_dev;
1066 if (res->r_dev != NULL) {
1067 if (device_get_name(res->r_dev) != NULL) {
1068 snprintf(ures.r_devname, RM_TEXTLEN,
1069 "%s%d",
1070 device_get_name(res->r_dev),
1071 device_get_unit(res->r_dev));
1072 } else {
1073 strlcpy(ures.r_devname, "nomatch",
1074 RM_TEXTLEN);
1075 }
1076 } else {
1077 ures.r_devname[0] = '\0';
1078 }
1079 ures.r_start = res->r_start;
1080 ures.r_size = res->r_end - res->r_start + 1;
1081 ures.r_flags = res->r_flags;
1082
1083 mtx_unlock(rm->rm_mtx);
1084 error = SYSCTL_OUT(req, &ures, sizeof(ures));
1085 return (error);
1086 }
1087
1088 SYSCTL_NODE(_hw_bus, OID_AUTO, rman, CTLFLAG_RD, sysctl_rman,
1089 "kernel resource manager");
1090
1091 #ifdef DDB
1092 static void
1093 dump_rman(struct rman *rm)
1094 {
1095 struct resource_i *r;
1096 const char *devname;
1097
1098 if (db_pager_quit)
1099 return;
1100 db_printf("rman: %s\n", rm->rm_descr);
1101 db_printf(" 0x%lx-0x%lx (full range)\n", rm->rm_start, rm->rm_end);
1102 TAILQ_FOREACH(r, &rm->rm_list, r_link) {
1103 if (r->r_dev != NULL) {
1104 devname = device_get_nameunit(r->r_dev);
1105 if (devname == NULL)
1106 devname = "nomatch";
1107 } else
1108 devname = NULL;
1109 db_printf(" 0x%lx-0x%lx ", r->r_start, r->r_end);
1110 if (devname != NULL)
1111 db_printf("(%s)\n", devname);
1112 else
1113 db_printf("----\n");
1114 if (db_pager_quit)
1115 return;
1116 }
1117 }
1118
1119 DB_SHOW_COMMAND(rman, db_show_rman)
1120 {
1121
1122 if (have_addr)
1123 dump_rman((struct rman *)addr);
1124 }
1125
1126 DB_SHOW_ALL_COMMAND(rman, db_show_all_rman)
1127 {
1128 struct rman *rm;
1129
1130 TAILQ_FOREACH(rm, &rman_head, rm_link)
1131 dump_rman(rm);
1132 }
1133 DB_SHOW_ALIAS(allrman, db_show_all_rman);
1134 #endif
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