1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2020 Alexander V. Chernikov 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 #include "opt_inet.h" 30 #include "opt_route.h" 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/lock.h> 35 #include <sys/malloc.h> 36 #include <sys/mbuf.h> 37 #include <sys/kernel.h> 38 39 #include <net/route/nhop_utils.h> 40 41 #define BLOCK_ITEMS (8 * sizeof(u_long)) /* Number of items for ffsl() */ 42 43 #define _BLOCKS_TO_SZ(_blocks) ((size_t)(_blocks) * sizeof(u_long)) 44 #define _BLOCKS_TO_ITEMS(_blocks) ((uint32_t)(_blocks) * BLOCK_ITEMS) 45 #define _ITEMS_TO_BLOCKS(_items) ((_items) / BLOCK_ITEMS) 46 47 static void _bitmask_init_idx(void *index, uint32_t items); 48 49 void 50 bitmask_init(struct bitmask_head *bh, void *idx, uint32_t num_items) 51 { 52 53 if (idx != NULL) 54 _bitmask_init_idx(idx, num_items); 55 56 memset(bh, 0, sizeof(struct bitmask_head)); 57 bh->blocks = _ITEMS_TO_BLOCKS(num_items); 58 bh->idx = (u_long *)idx; 59 } 60 61 uint32_t 62 bitmask_get_resize_items(const struct bitmask_head *bh) 63 { 64 if ((bh->items_count * 2 > _BLOCKS_TO_ITEMS(bh->blocks)) && bh->items_count < 65536) 65 return (_BLOCKS_TO_ITEMS(bh->blocks) * 2); 66 67 return (0); 68 } 69 70 int 71 bitmask_should_resize(const struct bitmask_head *bh) 72 { 73 74 return (bitmask_get_resize_items(bh) != 0); 75 } 76 77 #if 0 78 uint32_t 79 _bitmask_get_blocks(uint32_t items) 80 { 81 82 return (items / BLOCK_ITEMS); 83 } 84 #endif 85 86 size_t 87 bitmask_get_size(uint32_t items) 88 { 89 #if _KERNEL 90 KASSERT((items % BLOCK_ITEMS) == 0, 91 ("bitmask size needs to power of 2 and greater or equal to %zu", 92 BLOCK_ITEMS)); 93 #else 94 assert((items % BLOCK_ITEMS) == 0); 95 #endif 96 97 return (items / 8); 98 } 99 100 static void 101 _bitmask_init_idx(void *_idx, uint32_t items) 102 { 103 size_t size = bitmask_get_size(items); 104 u_long *idx = (u_long *)_idx; 105 106 /* Mark all as free */ 107 memset(idx, 0xFF, size); 108 *idx &= ~(u_long)1; /* Always skip index 0 */ 109 } 110 111 /* 112 * _try_merge api to allow shrinking? 113 */ 114 int 115 bitmask_copy(const struct bitmask_head *bi, void *new_idx, uint32_t new_items) 116 { 117 uint32_t new_blocks = _BLOCKS_TO_ITEMS(new_items); 118 119 _bitmask_init_idx(new_idx, new_items); 120 121 if (bi->blocks < new_blocks) { 122 /* extend current blocks */ 123 if (bi->blocks > 0) 124 memcpy(new_idx, bi->idx, _BLOCKS_TO_SZ(bi->blocks)); 125 return (0); 126 } else { 127 /* XXX: ensure all other blocks are non-zero */ 128 for (int i = new_blocks; i < bi->blocks; i++) { 129 } 130 131 return (1); 132 } 133 } 134 135 void 136 bitmask_swap(struct bitmask_head *bh, void *new_idx, uint32_t new_items, void **pidx) 137 { 138 void *old_ptr; 139 140 old_ptr = bh->idx; 141 142 bh->idx = (u_long *)new_idx; 143 bh->blocks = _ITEMS_TO_BLOCKS(new_items); 144 145 if (pidx != NULL) 146 *pidx = old_ptr; 147 } 148 149 /* 150 * Allocate new index in given instance and stores in in @pidx. 151 * Returns 0 on success. 152 */ 153 int 154 bitmask_alloc_idx(struct bitmask_head *bi, uint16_t *pidx) 155 { 156 u_long *mask; 157 int i, off, v; 158 159 off = bi->free_off; 160 mask = &bi->idx[off]; 161 162 for (i = off; i < bi->blocks; i++, mask++) { 163 if ((v = ffsl(*mask)) == 0) 164 continue; 165 166 /* Mark as busy */ 167 *mask &= ~ ((u_long)1 << (v - 1)); 168 169 bi->free_off = i; 170 171 v = BLOCK_ITEMS * i + v - 1; 172 173 *pidx = v; 174 bi->items_count++; 175 return (0); 176 } 177 178 return (1); 179 } 180 181 /* 182 * Removes index from given set. 183 * Returns 0 on success. 184 */ 185 int 186 bitmask_free_idx(struct bitmask_head *bi, uint16_t idx) 187 { 188 u_long *mask; 189 int i, v; 190 191 if (idx == 0) 192 return (1); 193 194 i = idx / BLOCK_ITEMS; 195 v = idx % BLOCK_ITEMS; 196 197 if (i >= bi->blocks) 198 return (1); 199 200 mask = &bi->idx[i]; 201 202 if ((*mask & ((u_long)1 << v)) != 0) 203 return (1); 204 205 /* Mark as free */ 206 *mask |= (u_long)1 << v; 207 bi->items_count--; 208 209 /* Update free offset */ 210 if (bi->free_off > i) 211 bi->free_off = i; 212 213 return (0); 214 } 215