1848b8605Smrg/* 2848b8605Smrg * Copyright 2007 Nouveau Project 3848b8605Smrg * 4848b8605Smrg * Permission is hereby granted, free of charge, to any person obtaining a 5848b8605Smrg * copy of this software and associated documentation files (the "Software"), 6848b8605Smrg * to deal in the Software without restriction, including without limitation 7848b8605Smrg * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8848b8605Smrg * and/or sell copies of the Software, and to permit persons to whom the 9848b8605Smrg * Software is furnished to do so, subject to the following conditions: 10848b8605Smrg * 11848b8605Smrg * The above copyright notice and this permission notice shall be included in 12848b8605Smrg * all copies or substantial portions of the Software. 13848b8605Smrg * 14848b8605Smrg * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 15848b8605Smrg * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16848b8605Smrg * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 17848b8605Smrg * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 18848b8605Smrg * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 19848b8605Smrg * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 20848b8605Smrg * OTHER DEALINGS IN THE SOFTWARE. 21848b8605Smrg */ 22848b8605Smrg 23848b8605Smrg#ifndef __NOUVEAU_HEAP_H__ 24848b8605Smrg#define __NOUVEAU_HEAP_H__ 25848b8605Smrg 26b8e80941Smrg/* This datastructure represents a memory allocation heap. Fundamentally, this 27b8e80941Smrg * is a doubly-linked list with a few properties, and a usage convention. 28b8e80941Smrg * 29b8e80941Smrg * On initial allocation, there is a single node with the full size that's 30b8e80941Smrg * marked as not in-use. As allocations are made, blocks are taken off the end 31b8e80941Smrg * of that first node, and inserted right after it. If the first node doesn't 32b8e80941Smrg * have enough free space, we look for free space down in the rest of the 33b8e80941Smrg * list. This can happen if an allocation is made and then freed. 34b8e80941Smrg * 35b8e80941Smrg * The first node will remain with in_use == 0 even if the whole heap is 36b8e80941Smrg * exhausted. Another invariant is that there will never be two sequential 37b8e80941Smrg * in_use == 0 nodes. If a node is freed and it has one (or both) adjacent 38b8e80941Smrg * free nodes, they are merged into one, and the relevant heap entries are 39b8e80941Smrg * freed. 40b8e80941Smrg * 41b8e80941Smrg * The pattern to free the whole heap is to start with the first node and then 42b8e80941Smrg * just free the "next" node, until there is no next node. This should assure 43b8e80941Smrg * that at the end the first (and only) node is not in use and contains the 44b8e80941Smrg * full size of the heap. 45b8e80941Smrg */ 46848b8605Smrgstruct nouveau_heap { 47b8e80941Smrg struct nouveau_heap *prev; 48b8e80941Smrg struct nouveau_heap *next; 49848b8605Smrg 50b8e80941Smrg void *priv; 51848b8605Smrg 52b8e80941Smrg unsigned start; 53b8e80941Smrg unsigned size; 54848b8605Smrg 55b8e80941Smrg int in_use; 56848b8605Smrg}; 57848b8605Smrg 58848b8605Smrgint 59848b8605Smrgnouveau_heap_init(struct nouveau_heap **heap, unsigned start, 60848b8605Smrg unsigned size); 61848b8605Smrg 62848b8605Smrgvoid 63848b8605Smrgnouveau_heap_destroy(struct nouveau_heap **heap); 64848b8605Smrg 65848b8605Smrgint 66848b8605Smrgnouveau_heap_alloc(struct nouveau_heap *heap, unsigned size, void *priv, 67848b8605Smrg struct nouveau_heap **); 68848b8605Smrg 69848b8605Smrgvoid 70848b8605Smrgnouveau_heap_free(struct nouveau_heap **); 71848b8605Smrg 72848b8605Smrg#endif 73