/*- * Copyright (c) 2010 Isilon Systems, Inc. * Copyright (c) 2010 iX Systems, Inc. * Copyright (c) 2010 Panasas, Inc. * Copyright (c) 2013-2018 Mellanox Technologies, Ltd. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice unmodified, this list of conditions, and the following * disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include static inline unsigned long radix_max(struct radix_tree_root *root) { return ((1UL << (root->height * RADIX_TREE_MAP_SHIFT)) - 1UL); } static inline int radix_pos(long id, int height) { return (id >> (RADIX_TREE_MAP_SHIFT * height)) & RADIX_TREE_MAP_MASK; } void * radix_tree_lookup(struct radix_tree_root *root, unsigned long index) { struct radix_tree_node *node; void *item; int height; item = NULL; node = root->rnode; height = root->height - 1; if (index > radix_max(root)) goto out; while (height && node) node = node->slots[radix_pos(index, height--)]; if (node) item = node->slots[radix_pos(index, 0)]; out: return (item); } bool radix_tree_iter_find(struct radix_tree_root *root, struct radix_tree_iter *iter, void ***pppslot) { struct radix_tree_node *node; unsigned long index = iter->index; int height; restart: node = root->rnode; if (node == NULL) return (false); height = root->height - 1; if (height == -1 || index > radix_max(root)) return (false); do { unsigned long mask = RADIX_TREE_MAP_MASK << (RADIX_TREE_MAP_SHIFT * height); unsigned long step = 1UL << (RADIX_TREE_MAP_SHIFT * height); int pos = radix_pos(index, height); struct radix_tree_node *next; /* track last slot */ *pppslot = node->slots + pos; next = node->slots[pos]; if (next == NULL) { index += step; index &= -step; if ((index & mask) == 0) goto restart; } else { node = next; height--; } } while (height != -1); iter->index = index; return (true); } void * radix_tree_delete(struct radix_tree_root *root, unsigned long index) { struct radix_tree_node *stack[RADIX_TREE_MAX_HEIGHT]; struct radix_tree_node *node; void *item; int height; int idx; item = NULL; node = root->rnode; height = root->height - 1; if (index > radix_max(root)) goto out; /* * Find the node and record the path in stack. */ while (height && node) { stack[height] = node; node = node->slots[radix_pos(index, height--)]; } idx = radix_pos(index, 0); if (node) item = node->slots[idx]; /* * If we removed something reduce the height of the tree. */ if (item) for (;;) { node->slots[idx] = NULL; node->count--; if (node->count > 0) break; kfree(node); if (node == root->rnode) { root->rnode = NULL; root->height = 0; break; } height++; node = stack[height]; idx = radix_pos(index, height); } out: return (item); } void radix_tree_iter_delete(struct radix_tree_root *root, struct radix_tree_iter *iter, void **slot) { radix_tree_delete(root, iter->index); } int radix_tree_insert(struct radix_tree_root *root, unsigned long index, void *item) { struct radix_tree_node *node; struct radix_tree_node *temp[RADIX_TREE_MAX_HEIGHT - 1]; int height; int idx; /* bail out upon insertion of a NULL item */ if (item == NULL) return (-EINVAL); /* get root node, if any */ node = root->rnode; /* allocate root node, if any */ if (node == NULL) { node = kmalloc(sizeof(*node), M_DRM, root->gfp_mask | M_ZERO); if (node == NULL) return (-ENOMEM); root->rnode = node; root->height++; } /* expand radix tree as needed */ while (radix_max(root) < index) { /* check if the radix tree is getting too big */ if (root->height == RADIX_TREE_MAX_HEIGHT) return (-E2BIG); /* * If the root radix level is not empty, we need to * allocate a new radix level: */ if (node->count != 0) { node = kmalloc(sizeof(*node), M_DRM, root->gfp_mask | M_ZERO); if (node == NULL) return (-ENOMEM); node->slots[0] = root->rnode; node->count++; root->rnode = node; } root->height++; } /* get radix tree height index */ height = root->height - 1; /* walk down the tree until the first missing node, if any */ for ( ; height != 0; height--) { idx = radix_pos(index, height); if (node->slots[idx] == NULL) break; node = node->slots[idx]; } /* allocate the missing radix levels, if any */ for (idx = 0; idx != height; idx++) { temp[idx] = kmalloc(sizeof(*node), M_DRM, root->gfp_mask | M_ZERO); if (temp[idx] == NULL) { while(idx--) kfree(temp[idx]); /* Check if we should free the root node as well. */ if (root->rnode->count == 0) { kfree(root->rnode); root->rnode = NULL; root->height = 0; } return (-ENOMEM); } } /* setup new radix levels, if any */ for ( ; height != 0; height--) { idx = radix_pos(index, height); node->slots[idx] = temp[height - 1]; node->count++; node = node->slots[idx]; } /* * Insert and adjust count if the item does not already exist. */ idx = radix_pos(index, 0); if (node->slots[idx]) return (-EEXIST); node->slots[idx] = item; node->count++; return (0); }