1 /* 2 * Copyright (c) 2018-2019 The Linux Foundation. All rights reserved. 3 * 4 * Permission to use, copy, modify, and/or distribute this software for 5 * any purpose with or without fee is hereby granted, provided that the 6 * above copyright notice and this permission notice appear in all 7 * copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL 10 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED 11 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE 12 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 13 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 14 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER 15 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 16 * PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 /** 20 * DOC: qdf_flex_mem (flexibly sized memory allocator) 21 * QCA driver framework (QDF) flex mem APIs 22 * 23 * A flex memory allocator is a memory pool which not only dynamically expands, 24 * but also dynamically reduces as well. Benefits over full dynamic memory 25 * allocation are amoritized allocation cost, and reduced memory fragmentation. 26 * 27 * The allocator consists of 3 parts: the pool, segments, and items. Items are 28 * the smallest chuncks of memory that are handed out via the alloc call, and 29 * are all of a uniform size. Segments are groups of items, representing the 30 * smallest amount of memory that can be dynamically allocated or freed. A pool 31 * is simply a collection of segments. 32 */ 33 34 #ifndef __QDF_FLEX_MEM_H 35 #define __QDF_FLEX_MEM_H 36 37 #include "qdf_list.h" 38 #include "qdf_lock.h" 39 40 #define QDF_FM_BITMAP uint32_t 41 #define QDF_FM_BITMAP_BITS (sizeof(QDF_FM_BITMAP) * 8) 42 43 /** 44 * qdf_flex_mem_pool - a pool of memory segments 45 * @seg_list: the list containing the memory segments 46 * @lock: spinlock for protecting internal data structures 47 * @reduction_limit: the minimum number of segments to keep during reduction 48 * @item_size: the size of the items the pool will allocate 49 */ 50 struct qdf_flex_mem_pool { 51 qdf_list_t seg_list; 52 struct qdf_spinlock lock; 53 uint16_t reduction_limit; 54 uint16_t item_size; 55 }; 56 57 /** 58 * qdf_flex_mem_segment - a memory pool segment 59 * @node: the list node for membership in the memory pool 60 * @dynamic: true if this segment was dynamically allocated 61 * @used_bitmap: bitmap for tracking which items in the segment are in use 62 * @bytes: raw memory for allocating items from 63 */ 64 struct qdf_flex_mem_segment { 65 qdf_list_node_t node; 66 bool dynamic; 67 QDF_FM_BITMAP used_bitmap; 68 uint8_t *bytes; 69 }; 70 71 /** 72 * DEFINE_QDF_FLEX_MEM_POOL() - define a new flex mem pool with one segment 73 * @name: the name of the pool variable 74 * @size_of_item: size of the items the pool will allocate 75 * @rm_limit: min number of segments to keep during reduction 76 */ 77 #define DEFINE_QDF_FLEX_MEM_POOL(name, size_of_item, rm_limit) \ 78 struct qdf_flex_mem_pool name; \ 79 uint8_t __ ## name ## _head_bytes[QDF_FM_BITMAP_BITS * (size_of_item)];\ 80 struct qdf_flex_mem_segment __ ## name ## _head = { \ 81 .node = QDF_LIST_NODE_INIT_SINGLE( \ 82 QDF_LIST_ANCHOR(name.seg_list)), \ 83 .bytes = __ ## name ## _head_bytes, \ 84 }; \ 85 struct qdf_flex_mem_pool name = { \ 86 .seg_list = QDF_LIST_INIT_SINGLE(__ ## name ## _head.node), \ 87 .reduction_limit = (rm_limit), \ 88 .item_size = (size_of_item), \ 89 } 90 91 /** 92 * qdf_flex_mem_init() - initialize a qdf_flex_mem_pool 93 * @pool: the pool to initialize 94 * 95 * Return: None 96 */ 97 void qdf_flex_mem_init(struct qdf_flex_mem_pool *pool); 98 99 /** 100 * qdf_flex_mem_deinit() - deinitialize a qdf_flex_mem_pool 101 * @pool: the pool to deinitialize 102 * 103 * Return: None 104 */ 105 void qdf_flex_mem_deinit(struct qdf_flex_mem_pool *pool); 106 107 /** 108 * qdf_flex_mem_alloc() - logically allocate memory from the pool 109 * @pool: the pool to allocate from 110 * 111 * This function returns any unused item from any existing segment in the pool. 112 * If there are no unused items in the pool, a new segment is dynamically 113 * allocated to service the request. The size of the allocated memory is the 114 * size originally used to create the pool. 115 * 116 * Return: Point to newly allocated memory, NULL on failure 117 */ 118 void *qdf_flex_mem_alloc(struct qdf_flex_mem_pool *pool); 119 120 /** 121 * qdf_flex_mem_free() - logically frees @ptr from the pool 122 * @pool: the pool to return the memory to 123 * @ptr: a pointer received via a call to qdf_flex_mem_alloc() 124 * 125 * This function marks the item corresponding to @ptr as unused. If that item 126 * was the last used item in the segment it belongs to, and the segment was 127 * dynamically allocated, the segment will be freed. 128 * 129 * Return: None 130 */ 131 void qdf_flex_mem_free(struct qdf_flex_mem_pool *pool, void *ptr); 132 133 #endif /* __QDF_FLEX_MEM_H */ 134