1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013-2018 Mellanox Technologies, Ltd. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice unmodified, this list of conditions, and the following 13 * disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/malloc.h> 36 #include <sys/kernel.h> 37 #include <sys/sysctl.h> 38 39 #include <linux/slab.h> 40 #include <linux/kernel.h> 41 #include <linux/radix-tree.h> 42 #include <linux/err.h> 43 44 static MALLOC_DEFINE(M_RADIX, "radix", "Linux radix compat"); 45 46 static inline unsigned long 47 radix_max(struct radix_tree_root *root) 48 { 49 return ((1UL << (root->height * RADIX_TREE_MAP_SHIFT)) - 1UL); 50 } 51 52 static inline int 53 radix_pos(long id, int height) 54 { 55 return (id >> (RADIX_TREE_MAP_SHIFT * height)) & RADIX_TREE_MAP_MASK; 56 } 57 58 void * 59 radix_tree_lookup(struct radix_tree_root *root, unsigned long index) 60 { 61 struct radix_tree_node *node; 62 void *item; 63 int height; 64 65 item = NULL; 66 node = root->rnode; 67 height = root->height - 1; 68 if (index > radix_max(root)) 69 goto out; 70 while (height && node) 71 node = node->slots[radix_pos(index, height--)]; 72 if (node) 73 item = node->slots[radix_pos(index, 0)]; 74 75 out: 76 return (item); 77 } 78 79 bool 80 radix_tree_iter_find(struct radix_tree_root *root, struct radix_tree_iter *iter, 81 void ***pppslot) 82 { 83 struct radix_tree_node *node; 84 unsigned long index = iter->index; 85 int height; 86 87 restart: 88 node = root->rnode; 89 if (node == NULL) 90 return (false); 91 height = root->height - 1; 92 if (height == -1 || index > radix_max(root)) 93 return (false); 94 do { 95 unsigned long mask = RADIX_TREE_MAP_MASK << (RADIX_TREE_MAP_SHIFT * height); 96 unsigned long step = 1UL << (RADIX_TREE_MAP_SHIFT * height); 97 int pos = radix_pos(index, height); 98 struct radix_tree_node *next; 99 100 /* track last slot */ 101 *pppslot = node->slots + pos; 102 103 next = node->slots[pos]; 104 if (next == NULL) { 105 index += step; 106 if ((index & mask) == 0) 107 goto restart; 108 } else { 109 node = next; 110 height--; 111 } 112 } while (height != -1); 113 iter->index = index; 114 return (true); 115 } 116 117 void * 118 radix_tree_delete(struct radix_tree_root *root, unsigned long index) 119 { 120 struct radix_tree_node *stack[RADIX_TREE_MAX_HEIGHT]; 121 struct radix_tree_node *node; 122 void *item; 123 int height; 124 int idx; 125 126 item = NULL; 127 node = root->rnode; 128 height = root->height - 1; 129 if (index > radix_max(root)) 130 goto out; 131 /* 132 * Find the node and record the path in stack. 133 */ 134 while (height && node) { 135 stack[height] = node; 136 node = node->slots[radix_pos(index, height--)]; 137 } 138 idx = radix_pos(index, 0); 139 if (node) 140 item = node->slots[idx]; 141 /* 142 * If we removed something reduce the height of the tree. 143 */ 144 if (item) 145 for (;;) { 146 node->slots[idx] = NULL; 147 node->count--; 148 if (node->count > 0) 149 break; 150 free(node, M_RADIX); 151 if (node == root->rnode) { 152 root->rnode = NULL; 153 root->height = 0; 154 break; 155 } 156 height++; 157 node = stack[height]; 158 idx = radix_pos(index, height); 159 } 160 out: 161 return (item); 162 } 163 164 int 165 radix_tree_insert(struct radix_tree_root *root, unsigned long index, void *item) 166 { 167 struct radix_tree_node *node; 168 struct radix_tree_node *temp[RADIX_TREE_MAX_HEIGHT - 1]; 169 int height; 170 int idx; 171 172 /* bail out upon insertion of a NULL item */ 173 if (item == NULL) 174 return (-EINVAL); 175 176 /* get root node, if any */ 177 node = root->rnode; 178 179 /* allocate root node, if any */ 180 if (node == NULL) { 181 node = malloc(sizeof(*node), M_RADIX, root->gfp_mask | M_ZERO); 182 if (node == NULL) 183 return (-ENOMEM); 184 root->rnode = node; 185 root->height++; 186 } 187 188 /* expand radix tree as needed */ 189 while (radix_max(root) < index) { 190 191 /* check if the radix tree is getting too big */ 192 if (root->height == RADIX_TREE_MAX_HEIGHT) 193 return (-E2BIG); 194 195 /* 196 * If the root radix level is not empty, we need to 197 * allocate a new radix level: 198 */ 199 if (node->count != 0) { 200 node = malloc(sizeof(*node), M_RADIX, root->gfp_mask | M_ZERO); 201 if (node == NULL) 202 return (-ENOMEM); 203 node->slots[0] = root->rnode; 204 node->count++; 205 root->rnode = node; 206 } 207 root->height++; 208 } 209 210 /* get radix tree height index */ 211 height = root->height - 1; 212 213 /* walk down the tree until the first missing node, if any */ 214 for ( ; height != 0; height--) { 215 idx = radix_pos(index, height); 216 if (node->slots[idx] == NULL) 217 break; 218 node = node->slots[idx]; 219 } 220 221 /* allocate the missing radix levels, if any */ 222 for (idx = 0; idx != height; idx++) { 223 temp[idx] = malloc(sizeof(*node), M_RADIX, 224 root->gfp_mask | M_ZERO); 225 if (temp[idx] == NULL) { 226 while(idx--) 227 free(temp[idx], M_RADIX); 228 /* Check if we should free the root node as well. */ 229 if (root->rnode->count == 0) { 230 free(root->rnode, M_RADIX); 231 root->rnode = NULL; 232 root->height = 0; 233 } 234 return (-ENOMEM); 235 } 236 } 237 238 /* setup new radix levels, if any */ 239 for ( ; height != 0; height--) { 240 idx = radix_pos(index, height); 241 node->slots[idx] = temp[height - 1]; 242 node->count++; 243 node = node->slots[idx]; 244 } 245 246 /* 247 * Insert and adjust count if the item does not already exist. 248 */ 249 idx = radix_pos(index, 0); 250 if (node->slots[idx]) 251 return (-EEXIST); 252 node->slots[idx] = item; 253 node->count++; 254 255 return (0); 256 } 257