1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 __FBSDID("$FreeBSD$"); 30 #include "opt_inet.h" 31 #include "opt_route.h" 32 #include "opt_mpath.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/lock.h> 37 #include <sys/malloc.h> 38 #include <sys/mbuf.h> 39 #include <sys/kernel.h> 40 41 #include <net/route/nhop_utils.h> 42 43 #define BLOCK_ITEMS (8 * sizeof(u_long)) /* Number of items for ffsl() */ 44 45 #define _BLOCKS_TO_SZ(_blocks) ((size_t)(_blocks) * sizeof(u_long)) 46 #define _BLOCKS_TO_ITEMS(_blocks) ((uint32_t)(_blocks) * BLOCK_ITEMS) 47 #define _ITEMS_TO_BLOCKS(_items) ((_items) / BLOCK_ITEMS) 48 49 static void _bitmask_init_idx(void *index, uint32_t items); 50 51 void 52 bitmask_init(struct bitmask_head *bh, void *idx, uint32_t num_items) 53 { 54 55 if (idx != NULL) 56 _bitmask_init_idx(idx, num_items); 57 58 memset(bh, 0, sizeof(struct bitmask_head)); 59 bh->blocks = _ITEMS_TO_BLOCKS(num_items); 60 bh->idx = (u_long *)idx; 61 } 62 63 uint32_t 64 bitmask_get_resize_items(const struct bitmask_head *bh) 65 { 66 if ((bh->items_count * 2 > _BLOCKS_TO_ITEMS(bh->blocks)) && bh->items_count < 65536) 67 return (_BLOCKS_TO_ITEMS(bh->blocks) * 2); 68 69 return (0); 70 } 71 72 int 73 bitmask_should_resize(const struct bitmask_head *bh) 74 { 75 76 return (bitmask_get_resize_items(bh) != 0); 77 } 78 79 #if 0 80 uint32_t 81 _bitmask_get_blocks(uint32_t items) 82 { 83 84 return (items / BLOCK_ITEMS); 85 } 86 #endif 87 88 size_t 89 bitmask_get_size(uint32_t items) 90 { 91 #if _KERNEL 92 KASSERT((items % BLOCK_ITEMS) == 0, 93 ("bitmask size needs to power of 2 and greater or equal to %zu", 94 BLOCK_ITEMS)); 95 #else 96 assert((items % BLOCK_ITEMS) == 0); 97 #endif 98 99 return (items / 8); 100 } 101 102 static void 103 _bitmask_init_idx(void *_idx, uint32_t items) 104 { 105 size_t size = bitmask_get_size(items); 106 u_long *idx = (u_long *)_idx; 107 108 /* Mark all as free */ 109 memset(idx, 0xFF, size); 110 *idx &= ~(u_long)1; /* Always skip index 0 */ 111 } 112 113 /* 114 * _try_merge api to allow shrinking? 115 */ 116 int 117 bitmask_copy(const struct bitmask_head *bi, void *new_idx, uint32_t new_items) 118 { 119 uint32_t new_blocks = _BLOCKS_TO_ITEMS(new_items); 120 121 _bitmask_init_idx(new_idx, new_items); 122 123 if (bi->blocks < new_blocks) { 124 /* extend current blocks */ 125 if (bi->blocks > 0) 126 memcpy(new_idx, bi->idx, _BLOCKS_TO_SZ(bi->blocks)); 127 return (0); 128 } else { 129 /* XXX: ensure all other blocks are non-zero */ 130 for (int i = new_blocks; i < bi->blocks; i++) { 131 } 132 133 return (1); 134 } 135 } 136 137 void 138 bitmask_swap(struct bitmask_head *bh, void *new_idx, uint32_t new_items, void **pidx) 139 { 140 void *old_ptr; 141 142 old_ptr = bh->idx; 143 144 bh->idx = (u_long *)new_idx; 145 bh->blocks = _ITEMS_TO_BLOCKS(new_items); 146 147 if (pidx != NULL) 148 *pidx = old_ptr; 149 } 150 151 /* 152 * Allocate new index in given instance and stores in in @pidx. 153 * Returns 0 on success. 154 */ 155 int 156 bitmask_alloc_idx(struct bitmask_head *bi, uint16_t *pidx) 157 { 158 u_long *mask; 159 int i, off, v; 160 161 off = bi->free_off; 162 mask = &bi->idx[off]; 163 164 for (i = off; i < bi->blocks; i++, mask++) { 165 if ((v = ffsl(*mask)) == 0) 166 continue; 167 168 /* Mark as busy */ 169 *mask &= ~ ((u_long)1 << (v - 1)); 170 171 bi->free_off = i; 172 173 v = BLOCK_ITEMS * i + v - 1; 174 175 *pidx = v; 176 bi->items_count++; 177 return (0); 178 } 179 180 return (1); 181 } 182 183 /* 184 * Removes index from given set. 185 * Returns 0 on success. 186 */ 187 int 188 bitmask_free_idx(struct bitmask_head *bi, uint16_t idx) 189 { 190 u_long *mask; 191 int i, v; 192 193 if (idx == 0) 194 return (1); 195 196 i = idx / BLOCK_ITEMS; 197 v = idx % BLOCK_ITEMS; 198 199 if (i >= bi->blocks) 200 return (1); 201 202 mask = &bi->idx[i]; 203 204 if ((*mask & ((u_long)1 << v)) != 0) 205 return (1); 206 207 /* Mark as free */ 208 *mask |= (u_long)1 << v; 209 bi->items_count--; 210 211 /* Update free offset */ 212 if (bi->free_off > i) 213 bi->free_off = i; 214 215 return (0); 216 } 217