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 50 static void _bitmask_init_idx(void *index, uint32_t items); 51 52 void 53 bitmask_init(struct bitmask_head *bh, void *idx, uint32_t num_items) 54 { 55 56 if (idx != NULL) 57 _bitmask_init_idx(idx, num_items); 58 59 memset(bh, 0, sizeof(struct bitmask_head)); 60 bh->blocks = _ITEMS_TO_BLOCKS(num_items); 61 bh->idx = (u_long *)idx; 62 } 63 64 uint32_t 65 bitmask_get_resize_items(const struct bitmask_head *bh) 66 { 67 if ((bh->items_count * 2 > _BLOCKS_TO_ITEMS(bh->blocks)) && bh->items_count < 65536) 68 return (_BLOCKS_TO_ITEMS(bh->blocks) * 2); 69 70 return (0); 71 } 72 73 int 74 bitmask_should_resize(const struct bitmask_head *bh) 75 { 76 77 return (bitmask_get_resize_items(bh) != 0); 78 } 79 80 #if 0 81 uint32_t 82 _bitmask_get_blocks(uint32_t items) 83 { 84 85 return (items / BLOCK_ITEMS); 86 } 87 #endif 88 89 size_t 90 bitmask_get_size(uint32_t items) 91 { 92 #if _KERNEL 93 KASSERT((items % BLOCK_ITEMS) == 0, 94 ("bitmask size needs to power of 2 and greater or equal to %zu", 95 BLOCK_ITEMS)); 96 #else 97 assert((items % BLOCK_ITEMS) == 0); 98 #endif 99 100 return (items / 8); 101 } 102 103 static void 104 _bitmask_init_idx(void *_idx, uint32_t items) 105 { 106 size_t size = bitmask_get_size(items); 107 u_long *idx = (u_long *)_idx; 108 109 /* Mark all as free */ 110 memset(idx, 0xFF, size); 111 *idx &= ~(u_long)1; /* Always skip index 0 */ 112 } 113 114 115 /* 116 * _try_merge api to allow shrinking? 117 */ 118 int 119 bitmask_copy(const struct bitmask_head *bi, void *new_idx, uint32_t new_items) 120 { 121 uint32_t new_blocks = _BLOCKS_TO_ITEMS(new_items); 122 123 _bitmask_init_idx(new_idx, new_items); 124 125 if (bi->blocks < new_blocks) { 126 /* extend current blocks */ 127 if (bi->blocks > 0) 128 memcpy(new_idx, bi->idx, _BLOCKS_TO_SZ(bi->blocks)); 129 return (0); 130 } else { 131 /* XXX: ensure all other blocks are non-zero */ 132 for (int i = new_blocks; i < bi->blocks; i++) { 133 } 134 135 return (1); 136 } 137 } 138 139 void 140 bitmask_swap(struct bitmask_head *bh, void *new_idx, uint32_t new_items, void **pidx) 141 { 142 void *old_ptr; 143 144 old_ptr = bh->idx; 145 146 bh->idx = (u_long *)new_idx; 147 bh->blocks = _ITEMS_TO_BLOCKS(new_items); 148 149 if (pidx != NULL) 150 *pidx = old_ptr; 151 } 152 153 /* 154 * Allocate new index in given instance and stores in in @pidx. 155 * Returns 0 on success. 156 */ 157 int 158 bitmask_alloc_idx(struct bitmask_head *bi, uint16_t *pidx) 159 { 160 u_long *mask; 161 int i, off, v; 162 163 off = bi->free_off; 164 mask = &bi->idx[off]; 165 166 for (i = off; i < bi->blocks; i++, mask++) { 167 if ((v = ffsl(*mask)) == 0) 168 continue; 169 170 /* Mark as busy */ 171 *mask &= ~ ((u_long)1 << (v - 1)); 172 173 bi->free_off = i; 174 175 v = BLOCK_ITEMS * i + v - 1; 176 177 *pidx = v; 178 bi->items_count++; 179 return (0); 180 } 181 182 return (1); 183 } 184 185 /* 186 * Removes index from given set. 187 * Returns 0 on success. 188 */ 189 int 190 bitmask_free_idx(struct bitmask_head *bi, uint16_t idx) 191 { 192 u_long *mask; 193 int i, v; 194 195 if (idx == 0) 196 return (1); 197 198 i = idx / BLOCK_ITEMS; 199 v = idx % BLOCK_ITEMS; 200 201 if (i >= bi->blocks) 202 return (1); 203 204 mask = &bi->idx[i]; 205 206 if ((*mask & ((u_long)1 << v)) != 0) 207 return (1); 208 209 /* Mark as free */ 210 *mask |= (u_long)1 << v; 211 bi->items_count--; 212 213 /* Update free offset */ 214 if (bi->free_off > i) 215 bi->free_off = i; 216 217 return (0); 218 } 219 220