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-rw-r--r--arch/powerpc/lib/rheap.c693
1 files changed, 693 insertions, 0 deletions
diff --git a/arch/powerpc/lib/rheap.c b/arch/powerpc/lib/rheap.c
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1/*
2 * arch/ppc/syslib/rheap.c
3 *
4 * A Remote Heap. Remote means that we don't touch the memory that the
5 * heap points to. Normal heap implementations use the memory they manage
6 * to place their list. We cannot do that because the memory we manage may
7 * have special properties, for example it is uncachable or of different
8 * endianess.
9 *
10 * Author: Pantelis Antoniou <panto@intracom.gr>
11 *
12 * 2004 (c) INTRACOM S.A. Greece. This file is licensed under
13 * the terms of the GNU General Public License version 2. This program
14 * is licensed "as is" without any warranty of any kind, whether express
15 * or implied.
16 */
17#include <linux/types.h>
18#include <linux/errno.h>
19#include <linux/mm.h>
20#include <linux/slab.h>
21
22#include <asm/rheap.h>
23
24/*
25 * Fixup a list_head, needed when copying lists. If the pointers fall
26 * between s and e, apply the delta. This assumes that
27 * sizeof(struct list_head *) == sizeof(unsigned long *).
28 */
29static inline void fixup(unsigned long s, unsigned long e, int d,
30 struct list_head *l)
31{
32 unsigned long *pp;
33
34 pp = (unsigned long *)&l->next;
35 if (*pp >= s && *pp < e)
36 *pp += d;
37
38 pp = (unsigned long *)&l->prev;
39 if (*pp >= s && *pp < e)
40 *pp += d;
41}
42
43/* Grow the allocated blocks */
44static int grow(rh_info_t * info, int max_blocks)
45{
46 rh_block_t *block, *blk;
47 int i, new_blocks;
48 int delta;
49 unsigned long blks, blke;
50
51 if (max_blocks <= info->max_blocks)
52 return -EINVAL;
53
54 new_blocks = max_blocks - info->max_blocks;
55
56 block = kmalloc(sizeof(rh_block_t) * max_blocks, GFP_KERNEL);
57 if (block == NULL)
58 return -ENOMEM;
59
60 if (info->max_blocks > 0) {
61
62 /* copy old block area */
63 memcpy(block, info->block,
64 sizeof(rh_block_t) * info->max_blocks);
65
66 delta = (char *)block - (char *)info->block;
67
68 /* and fixup list pointers */
69 blks = (unsigned long)info->block;
70 blke = (unsigned long)(info->block + info->max_blocks);
71
72 for (i = 0, blk = block; i < info->max_blocks; i++, blk++)
73 fixup(blks, blke, delta, &blk->list);
74
75 fixup(blks, blke, delta, &info->empty_list);
76 fixup(blks, blke, delta, &info->free_list);
77 fixup(blks, blke, delta, &info->taken_list);
78
79 /* free the old allocated memory */
80 if ((info->flags & RHIF_STATIC_BLOCK) == 0)
81 kfree(info->block);
82 }
83
84 info->block = block;
85 info->empty_slots += new_blocks;
86 info->max_blocks = max_blocks;
87 info->flags &= ~RHIF_STATIC_BLOCK;
88
89 /* add all new blocks to the free list */
90 for (i = 0, blk = block + info->max_blocks; i < new_blocks; i++, blk++)
91 list_add(&blk->list, &info->empty_list);
92
93 return 0;
94}
95
96/*
97 * Assure at least the required amount of empty slots. If this function
98 * causes a grow in the block area then all pointers kept to the block
99 * area are invalid!
100 */
101static int assure_empty(rh_info_t * info, int slots)
102{
103 int max_blocks;
104
105 /* This function is not meant to be used to grow uncontrollably */
106 if (slots >= 4)
107 return -EINVAL;
108
109 /* Enough space */
110 if (info->empty_slots >= slots)
111 return 0;
112
113 /* Next 16 sized block */
114 max_blocks = ((info->max_blocks + slots) + 15) & ~15;
115
116 return grow(info, max_blocks);
117}
118
119static rh_block_t *get_slot(rh_info_t * info)
120{
121 rh_block_t *blk;
122
123 /* If no more free slots, and failure to extend. */
124 /* XXX: You should have called assure_empty before */
125 if (info->empty_slots == 0) {
126 printk(KERN_ERR "rh: out of slots; crash is imminent.\n");
127 return NULL;
128 }
129
130 /* Get empty slot to use */
131 blk = list_entry(info->empty_list.next, rh_block_t, list);
132 list_del_init(&blk->list);
133 info->empty_slots--;
134
135 /* Initialize */
136 blk->start = NULL;
137 blk->size = 0;
138 blk->owner = NULL;
139
140 return blk;
141}
142
143static inline void release_slot(rh_info_t * info, rh_block_t * blk)
144{
145 list_add(&blk->list, &info->empty_list);
146 info->empty_slots++;
147}
148
149static void attach_free_block(rh_info_t * info, rh_block_t * blkn)
150{
151 rh_block_t *blk;
152 rh_block_t *before;
153 rh_block_t *after;
154 rh_block_t *next;
155 int size;
156 unsigned long s, e, bs, be;
157 struct list_head *l;
158
159 /* We assume that they are aligned properly */
160 size = blkn->size;
161 s = (unsigned long)blkn->start;
162 e = s + size;
163
164 /* Find the blocks immediately before and after the given one
165 * (if any) */
166 before = NULL;
167 after = NULL;
168 next = NULL;
169
170 list_for_each(l, &info->free_list) {
171 blk = list_entry(l, rh_block_t, list);
172
173 bs = (unsigned long)blk->start;
174 be = bs + blk->size;
175
176 if (next == NULL && s >= bs)
177 next = blk;
178
179 if (be == s)
180 before = blk;
181
182 if (e == bs)
183 after = blk;
184
185 /* If both are not null, break now */
186 if (before != NULL && after != NULL)
187 break;
188 }
189
190 /* Now check if they are really adjacent */
191 if (before != NULL && s != (unsigned long)before->start + before->size)
192 before = NULL;
193
194 if (after != NULL && e != (unsigned long)after->start)
195 after = NULL;
196
197 /* No coalescing; list insert and return */
198 if (before == NULL && after == NULL) {
199
200 if (next != NULL)
201 list_add(&blkn->list, &next->list);
202 else
203 list_add(&blkn->list, &info->free_list);
204
205 return;
206 }
207
208 /* We don't need it anymore */
209 release_slot(info, blkn);
210
211 /* Grow the before block */
212 if (before != NULL && after == NULL) {
213 before->size += size;
214 return;
215 }
216
217 /* Grow the after block backwards */
218 if (before == NULL && after != NULL) {
219 after->start = (int8_t *)after->start - size;
220 after->size += size;
221 return;
222 }
223
224 /* Grow the before block, and release the after block */
225 before->size += size + after->size;
226 list_del(&after->list);
227 release_slot(info, after);
228}
229
230static void attach_taken_block(rh_info_t * info, rh_block_t * blkn)
231{
232 rh_block_t *blk;
233 struct list_head *l;
234
235 /* Find the block immediately before the given one (if any) */
236 list_for_each(l, &info->taken_list) {
237 blk = list_entry(l, rh_block_t, list);
238 if (blk->start > blkn->start) {
239 list_add_tail(&blkn->list, &blk->list);
240 return;
241 }
242 }
243
244 list_add_tail(&blkn->list, &info->taken_list);
245}
246
247/*
248 * Create a remote heap dynamically. Note that no memory for the blocks
249 * are allocated. It will upon the first allocation
250 */
251rh_info_t *rh_create(unsigned int alignment)
252{
253 rh_info_t *info;
254
255 /* Alignment must be a power of two */
256 if ((alignment & (alignment - 1)) != 0)
257 return ERR_PTR(-EINVAL);
258
259 info = kmalloc(sizeof(*info), GFP_KERNEL);
260 if (info == NULL)
261 return ERR_PTR(-ENOMEM);
262
263 info->alignment = alignment;
264
265 /* Initially everything as empty */
266 info->block = NULL;
267 info->max_blocks = 0;
268 info->empty_slots = 0;
269 info->flags = 0;
270
271 INIT_LIST_HEAD(&info->empty_list);
272 INIT_LIST_HEAD(&info->free_list);
273 INIT_LIST_HEAD(&info->taken_list);
274
275 return info;
276}
277
278/*
279 * Destroy a dynamically created remote heap. Deallocate only if the areas
280 * are not static
281 */
282void rh_destroy(rh_info_t * info)
283{
284 if ((info->flags & RHIF_STATIC_BLOCK) == 0 && info->block != NULL)
285 kfree(info->block);
286
287 if ((info->flags & RHIF_STATIC_INFO) == 0)
288 kfree(info);
289}
290
291/*
292 * Initialize in place a remote heap info block. This is needed to support
293 * operation very early in the startup of the kernel, when it is not yet safe
294 * to call kmalloc.
295 */
296void rh_init(rh_info_t * info, unsigned int alignment, int max_blocks,
297 rh_block_t * block)
298{
299 int i;
300 rh_block_t *blk;
301
302 /* Alignment must be a power of two */
303 if ((alignment & (alignment - 1)) != 0)
304 return;
305
306 info->alignment = alignment;
307
308 /* Initially everything as empty */
309 info->block = block;
310 info->max_blocks = max_blocks;
311 info->empty_slots = max_blocks;
312 info->flags = RHIF_STATIC_INFO | RHIF_STATIC_BLOCK;
313
314 INIT_LIST_HEAD(&info->empty_list);
315 INIT_LIST_HEAD(&info->free_list);
316 INIT_LIST_HEAD(&info->taken_list);
317
318 /* Add all new blocks to the free list */
319 for (i = 0, blk = block; i < max_blocks; i++, blk++)
320 list_add(&blk->list, &info->empty_list);
321}
322
323/* Attach a free memory region, coalesces regions if adjuscent */
324int rh_attach_region(rh_info_t * info, void *start, int size)
325{
326 rh_block_t *blk;
327 unsigned long s, e, m;
328 int r;
329
330 /* The region must be aligned */
331 s = (unsigned long)start;
332 e = s + size;
333 m = info->alignment - 1;
334
335 /* Round start up */
336 s = (s + m) & ~m;
337
338 /* Round end down */
339 e = e & ~m;
340
341 /* Take final values */
342 start = (void *)s;
343 size = (int)(e - s);
344
345 /* Grow the blocks, if needed */
346 r = assure_empty(info, 1);
347 if (r < 0)
348 return r;
349
350 blk = get_slot(info);
351 blk->start = start;
352 blk->size = size;
353 blk->owner = NULL;
354
355 attach_free_block(info, blk);
356
357 return 0;
358}
359
360/* Detatch given address range, splits free block if needed. */
361void *rh_detach_region(rh_info_t * info, void *start, int size)
362{
363 struct list_head *l;
364 rh_block_t *blk, *newblk;
365 unsigned long s, e, m, bs, be;
366
367 /* Validate size */
368 if (size <= 0)
369 return ERR_PTR(-EINVAL);
370
371 /* The region must be aligned */
372 s = (unsigned long)start;
373 e = s + size;
374 m = info->alignment - 1;
375
376 /* Round start up */
377 s = (s + m) & ~m;
378
379 /* Round end down */
380 e = e & ~m;
381
382 if (assure_empty(info, 1) < 0)
383 return ERR_PTR(-ENOMEM);
384
385 blk = NULL;
386 list_for_each(l, &info->free_list) {
387 blk = list_entry(l, rh_block_t, list);
388 /* The range must lie entirely inside one free block */
389 bs = (unsigned long)blk->start;
390 be = (unsigned long)blk->start + blk->size;
391 if (s >= bs && e <= be)
392 break;
393 blk = NULL;
394 }
395
396 if (blk == NULL)
397 return ERR_PTR(-ENOMEM);
398
399 /* Perfect fit */
400 if (bs == s && be == e) {
401 /* Delete from free list, release slot */
402 list_del(&blk->list);
403 release_slot(info, blk);
404 return (void *)s;
405 }
406
407 /* blk still in free list, with updated start and/or size */
408 if (bs == s || be == e) {
409 if (bs == s)
410 blk->start = (int8_t *)blk->start + size;
411 blk->size -= size;
412
413 } else {
414 /* The front free fragment */
415 blk->size = s - bs;
416
417 /* the back free fragment */
418 newblk = get_slot(info);
419 newblk->start = (void *)e;
420 newblk->size = be - e;
421
422 list_add(&newblk->list, &blk->list);
423 }
424
425 return (void *)s;
426}
427
428void *rh_alloc(rh_info_t * info, int size, const char *owner)
429{
430 struct list_head *l;
431 rh_block_t *blk;
432 rh_block_t *newblk;
433 void *start;
434
435 /* Validate size */
436 if (size <= 0)
437 return ERR_PTR(-EINVAL);
438
439 /* Align to configured alignment */
440 size = (size + (info->alignment - 1)) & ~(info->alignment - 1);
441
442 if (assure_empty(info, 1) < 0)
443 return ERR_PTR(-ENOMEM);
444
445 blk = NULL;
446 list_for_each(l, &info->free_list) {
447 blk = list_entry(l, rh_block_t, list);
448 if (size <= blk->size)
449 break;
450 blk = NULL;
451 }
452
453 if (blk == NULL)
454 return ERR_PTR(-ENOMEM);
455
456 /* Just fits */
457 if (blk->size == size) {
458 /* Move from free list to taken list */
459 list_del(&blk->list);
460 blk->owner = owner;
461 start = blk->start;
462
463 attach_taken_block(info, blk);
464
465 return start;
466 }
467
468 newblk = get_slot(info);
469 newblk->start = blk->start;
470 newblk->size = size;
471 newblk->owner = owner;
472
473 /* blk still in free list, with updated start, size */
474 blk->start = (int8_t *)blk->start + size;
475 blk->size -= size;
476
477 start = newblk->start;
478
479 attach_taken_block(info, newblk);
480
481 return start;
482}
483
484/* allocate at precisely the given address */
485void *rh_alloc_fixed(rh_info_t * info, void *start, int size, const char *owner)
486{
487 struct list_head *l;
488 rh_block_t *blk, *newblk1, *newblk2;
489 unsigned long s, e, m, bs, be;
490
491 /* Validate size */
492 if (size <= 0)
493 return ERR_PTR(-EINVAL);
494
495 /* The region must be aligned */
496 s = (unsigned long)start;
497 e = s + size;
498 m = info->alignment - 1;
499
500 /* Round start up */
501 s = (s + m) & ~m;
502
503 /* Round end down */
504 e = e & ~m;
505
506 if (assure_empty(info, 2) < 0)
507 return ERR_PTR(-ENOMEM);
508
509 blk = NULL;
510 list_for_each(l, &info->free_list) {
511 blk = list_entry(l, rh_block_t, list);
512 /* The range must lie entirely inside one free block */
513 bs = (unsigned long)blk->start;
514 be = (unsigned long)blk->start + blk->size;
515 if (s >= bs && e <= be)
516 break;
517 }
518
519 if (blk == NULL)
520 return ERR_PTR(-ENOMEM);
521
522 /* Perfect fit */
523 if (bs == s && be == e) {
524 /* Move from free list to taken list */
525 list_del(&blk->list);
526 blk->owner = owner;
527
528 start = blk->start;
529 attach_taken_block(info, blk);
530
531 return start;
532
533 }
534
535 /* blk still in free list, with updated start and/or size */
536 if (bs == s || be == e) {
537 if (bs == s)
538 blk->start = (int8_t *)blk->start + size;
539 blk->size -= size;
540
541 } else {
542 /* The front free fragment */
543 blk->size = s - bs;
544
545 /* The back free fragment */
546 newblk2 = get_slot(info);
547 newblk2->start = (void *)e;
548 newblk2->size = be - e;
549
550 list_add(&newblk2->list, &blk->list);
551 }
552
553 newblk1 = get_slot(info);
554 newblk1->start = (void *)s;
555 newblk1->size = e - s;
556 newblk1->owner = owner;
557
558 start = newblk1->start;
559 attach_taken_block(info, newblk1);
560
561 return start;
562}
563
564int rh_free(rh_info_t * info, void *start)
565{
566 rh_block_t *blk, *blk2;
567 struct list_head *l;
568 int size;
569
570 /* Linear search for block */
571 blk = NULL;
572 list_for_each(l, &info->taken_list) {
573 blk2 = list_entry(l, rh_block_t, list);
574 if (start < blk2->start)
575 break;
576 blk = blk2;
577 }
578
579 if (blk == NULL || start > (blk->start + blk->size))
580 return -EINVAL;
581
582 /* Remove from taken list */
583 list_del(&blk->list);
584
585 /* Get size of freed block */
586 size = blk->size;
587 attach_free_block(info, blk);
588
589 return size;
590}
591
592int rh_get_stats(rh_info_t * info, int what, int max_stats, rh_stats_t * stats)
593{
594 rh_block_t *blk;
595 struct list_head *l;
596 struct list_head *h;
597 int nr;
598
599 switch (what) {
600
601 case RHGS_FREE:
602 h = &info->free_list;
603 break;
604
605 case RHGS_TAKEN:
606 h = &info->taken_list;
607 break;
608
609 default:
610 return -EINVAL;
611 }
612
613 /* Linear search for block */
614 nr = 0;
615 list_for_each(l, h) {
616 blk = list_entry(l, rh_block_t, list);
617 if (stats != NULL && nr < max_stats) {
618 stats->start = blk->start;
619 stats->size = blk->size;
620 stats->owner = blk->owner;
621 stats++;
622 }
623 nr++;
624 }
625
626 return nr;
627}
628
629int rh_set_owner(rh_info_t * info, void *start, const char *owner)
630{
631 rh_block_t *blk, *blk2;
632 struct list_head *l;
633 int size;
634
635 /* Linear search for block */
636 blk = NULL;
637 list_for_each(l, &info->taken_list) {
638 blk2 = list_entry(l, rh_block_t, list);
639 if (start < blk2->start)
640 break;
641 blk = blk2;
642 }
643
644 if (blk == NULL || start > (blk->start + blk->size))
645 return -EINVAL;
646
647 blk->owner = owner;
648 size = blk->size;
649
650 return size;
651}
652
653void rh_dump(rh_info_t * info)
654{
655 static rh_stats_t st[32]; /* XXX maximum 32 blocks */
656 int maxnr;
657 int i, nr;
658
659 maxnr = sizeof(st) / sizeof(st[0]);
660
661 printk(KERN_INFO
662 "info @0x%p (%d slots empty / %d max)\n",
663 info, info->empty_slots, info->max_blocks);
664
665 printk(KERN_INFO " Free:\n");
666 nr = rh_get_stats(info, RHGS_FREE, maxnr, st);
667 if (nr > maxnr)
668 nr = maxnr;
669 for (i = 0; i < nr; i++)
670 printk(KERN_INFO
671 " 0x%p-0x%p (%u)\n",
672 st[i].start, (int8_t *) st[i].start + st[i].size,
673 st[i].size);
674 printk(KERN_INFO "\n");
675
676 printk(KERN_INFO " Taken:\n");
677 nr = rh_get_stats(info, RHGS_TAKEN, maxnr, st);
678 if (nr > maxnr)
679 nr = maxnr;
680 for (i = 0; i < nr; i++)
681 printk(KERN_INFO
682 " 0x%p-0x%p (%u) %s\n",
683 st[i].start, (int8_t *) st[i].start + st[i].size,
684 st[i].size, st[i].owner != NULL ? st[i].owner : "");
685 printk(KERN_INFO "\n");
686}
687
688void rh_dump_blk(rh_info_t * info, rh_block_t * blk)
689{
690 printk(KERN_INFO
691 "blk @0x%p: 0x%p-0x%p (%u)\n",
692 blk, blk->start, (int8_t *) blk->start + blk->size, blk->size);
693}