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      1 /*
      2  * Copyright 2007 Nouveau Project
      3  *
      4  * Permission is hereby granted, free of charge, to any person obtaining a
      5  * copy of this software and associated documentation files (the "Software"),
      6  * to deal in the Software without restriction, including without limitation
      7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
      8  * and/or sell copies of the Software, and to permit persons to whom the
      9  * Software is furnished to do so, subject to the following conditions:
     10  *
     11  * The above copyright notice and this permission notice shall be included in
     12  * all copies or substantial portions of the Software.
     13  *
     14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     17  * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
     18  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
     19  * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
     20  * SOFTWARE.
     21  */
     22 
     23 #include <stdlib.h>
     24 #include <errno.h>
     25 
     26 #include "nouveau_heap.h"
     27 
     28 int
     29 nouveau_heap_init(struct nouveau_heap **heap,
     30                   unsigned start, unsigned size)
     31 {
     32 	struct nouveau_heap *r;
     33 
     34 	r = calloc(1, sizeof(struct nouveau_heap));
     35 	if (!r)
     36 		return 1;
     37 
     38 	r->start = start;
     39 	r->size  = size;
     40 	*heap = r;
     41 	return 0;
     42 }
     43 
     44 void
     45 nouveau_heap_destroy(struct nouveau_heap **heap)
     46 {
     47 	if (!*heap)
     48 		return;
     49 	free(*heap);
     50 	*heap = NULL;
     51 }
     52 
     53 int
     54 nouveau_heap_alloc(struct nouveau_heap *heap, unsigned size, void *priv,
     55                    struct nouveau_heap **res)
     56 {
     57 	struct nouveau_heap *r;
     58 
     59 	if (!heap || !size || !res || *res)
     60 		return 1;
     61 
     62 	while (heap) {
     63 		if (!heap->in_use && heap->size >= size) {
     64 			r = calloc(1, sizeof(struct nouveau_heap));
     65 			if (!r)
     66 				return 1;
     67 
     68 			r->start  = (heap->start + heap->size) - size;
     69 			r->size   = size;
     70 			r->in_use = 1;
     71 			r->priv   = priv;
     72 
     73 			heap->size -= size;
     74 
     75 			r->next = heap->next;
     76 			if (heap->next)
     77 				heap->next->prev = r;
     78 			r->prev = heap;
     79 			heap->next = r;
     80 
     81 			*res = r;
     82 			return 0;
     83 		}
     84 
     85 		heap = heap->next;
     86 	}
     87 
     88 	return 1;
     89 }
     90 
     91 void
     92 nouveau_heap_free(struct nouveau_heap **res)
     93 {
     94 	struct nouveau_heap *r;
     95 
     96 	if (!res || !*res)
     97 		return;
     98 	r = *res;
     99 	*res = NULL;
    100 
    101 	r->in_use = 0;
    102 
    103 	if (r->next && !r->next->in_use) {
    104 		struct nouveau_heap *new = r->next;
    105 
    106 		new->prev = r->prev;
    107 		if (r->prev)
    108 			r->prev->next = new;
    109 		new->size += r->size;
    110 		new->start = r->start;
    111 
    112 		free(r);
    113 		r = new;
    114 	}
    115 
    116 	if (r->prev && !r->prev->in_use) {
    117 		r->prev->next = r->next;
    118 		if (r->next)
    119 			r->next->prev = r->prev;
    120 		r->prev->size += r->size;
    121 		free(r);
    122 	}
    123 }
    124