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Diffstat (limited to 'arch/s390/numa/toptree.c')
| -rw-r--r-- | arch/s390/numa/toptree.c | 351 |
1 files changed, 0 insertions, 351 deletions
diff --git a/arch/s390/numa/toptree.c b/arch/s390/numa/toptree.c deleted file mode 100644 index 71a608cd4f61..000000000000 --- a/arch/s390/numa/toptree.c +++ /dev/null @@ -1,351 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * NUMA support for s390 - * - * A tree structure used for machine topology mangling - * - * Copyright IBM Corp. 2015 - */ - -#include <linux/kernel.h> -#include <linux/memblock.h> -#include <linux/cpumask.h> -#include <linux/list.h> -#include <linux/list_sort.h> -#include <linux/slab.h> -#include <asm/numa.h> - -#include "toptree.h" - -/** - * toptree_alloc - Allocate and initialize a new tree node. - * @level: The node's vertical level; level 0 contains the leaves. - * @id: ID number, explicitly not unique beyond scope of node's siblings - * - * Allocate a new tree node and initialize it. - * - * RETURNS: - * Pointer to the new tree node or NULL on error - */ -struct toptree __ref *toptree_alloc(int level, int id) -{ - struct toptree *res; - - if (slab_is_available()) - res = kzalloc(sizeof(*res), GFP_KERNEL); - else - res = memblock_alloc(sizeof(*res), 8); - if (!res) - return res; - - INIT_LIST_HEAD(&res->children); - INIT_LIST_HEAD(&res->sibling); - cpumask_clear(&res->mask); - res->level = level; - res->id = id; - return res; -} - -/** - * toptree_remove - Remove a tree node from a tree - * @cand: Pointer to the node to remove - * - * The node is detached from its parent node. The parent node's - * masks will be updated to reflect the loss of the child. - */ -static void toptree_remove(struct toptree *cand) -{ - struct toptree *oldparent; - - list_del_init(&cand->sibling); - oldparent = cand->parent; - cand->parent = NULL; - toptree_update_mask(oldparent); -} - -/** - * toptree_free - discard a tree node - * @cand: Pointer to the tree node to discard - * - * Checks if @cand is attached to a parent node. Detaches it - * cleanly using toptree_remove. Possible children are freed - * recursively. In the end @cand itself is freed. - */ -void __ref toptree_free(struct toptree *cand) -{ - struct toptree *child, *tmp; - - if (cand->parent) - toptree_remove(cand); - toptree_for_each_child_safe(child, tmp, cand) - toptree_free(child); - if (slab_is_available()) - kfree(cand); - else - memblock_free_early((unsigned long)cand, sizeof(*cand)); -} - -/** - * toptree_update_mask - Update node bitmasks - * @cand: Pointer to a tree node - * - * The node's cpumask will be updated by combining all children's - * masks. Then toptree_update_mask is called recursively for the - * parent if applicable. - * - * NOTE: - * This must not be called on leaves. If called on a leaf, its - * CPU mask is cleared and lost. - */ -void toptree_update_mask(struct toptree *cand) -{ - struct toptree *child; - - cpumask_clear(&cand->mask); - list_for_each_entry(child, &cand->children, sibling) - cpumask_or(&cand->mask, &cand->mask, &child->mask); - if (cand->parent) - toptree_update_mask(cand->parent); -} - -/** - * toptree_insert - Insert a tree node into tree - * @cand: Pointer to the node to insert - * @target: Pointer to the node to which @cand will added as a child - * - * Insert a tree node into a tree. Masks will be updated automatically. - * - * RETURNS: - * 0 on success, -1 if NULL is passed as argument or the node levels - * don't fit. - */ -static int toptree_insert(struct toptree *cand, struct toptree *target) -{ - if (!cand || !target) - return -1; - if (target->level != (cand->level + 1)) - return -1; - list_add_tail(&cand->sibling, &target->children); - cand->parent = target; - toptree_update_mask(target); - return 0; -} - -/** - * toptree_move_children - Move all child nodes of a node to a new place - * @cand: Pointer to the node whose children are to be moved - * @target: Pointer to the node to which @cand's children will be attached - * - * Take all child nodes of @cand and move them using toptree_move. - */ -static void toptree_move_children(struct toptree *cand, struct toptree *target) -{ - struct toptree *child, *tmp; - - toptree_for_each_child_safe(child, tmp, cand) - toptree_move(child, target); -} - -/** - * toptree_unify - Merge children with same ID - * @cand: Pointer to node whose direct children should be made unique - * - * When mangling the tree it is possible that a node has two or more children - * which have the same ID. This routine merges these children into one and - * moves all children of the merged nodes into the unified node. - */ -void toptree_unify(struct toptree *cand) -{ - struct toptree *child, *tmp, *cand_copy; - - /* Threads cannot be split, cores are not split */ - if (cand->level < 2) - return; - - cand_copy = toptree_alloc(cand->level, 0); - toptree_for_each_child_safe(child, tmp, cand) { - struct toptree *tmpchild; - - if (!cpumask_empty(&child->mask)) { - tmpchild = toptree_get_child(cand_copy, child->id); - toptree_move_children(child, tmpchild); - } - toptree_free(child); - } - toptree_move_children(cand_copy, cand); - toptree_free(cand_copy); - - toptree_for_each_child(child, cand) - toptree_unify(child); -} - -/** - * toptree_move - Move a node to another context - * @cand: Pointer to the node to move - * @target: Pointer to the node where @cand should go - * - * In the easiest case @cand is exactly on the level below @target - * and will be immediately moved to the target. - * - * If @target's level is not the direct parent level of @cand, - * nodes for the missing levels are created and put between - * @cand and @target. The "stacking" nodes' IDs are taken from - * @cand's parents. - * - * After this it is likely to have redundant nodes in the tree - * which are addressed by means of toptree_unify. - */ -void toptree_move(struct toptree *cand, struct toptree *target) -{ - struct toptree *stack_target, *real_insert_point, *ptr, *tmp; - - if (cand->level + 1 == target->level) { - toptree_remove(cand); - toptree_insert(cand, target); - return; - } - - real_insert_point = NULL; - ptr = cand; - stack_target = NULL; - - do { - tmp = stack_target; - stack_target = toptree_alloc(ptr->level + 1, - ptr->parent->id); - toptree_insert(tmp, stack_target); - if (!real_insert_point) - real_insert_point = stack_target; - ptr = ptr->parent; - } while (stack_target->level < (target->level - 1)); - - toptree_remove(cand); - toptree_insert(cand, real_insert_point); - toptree_insert(stack_target, target); -} - -/** - * toptree_get_child - Access a tree node's child by its ID - * @cand: Pointer to tree node whose child is to access - * @id: The desired child's ID - * - * @cand's children are searched for a child with matching ID. - * If no match can be found, a new child with the desired ID - * is created and returned. - */ -struct toptree *toptree_get_child(struct toptree *cand, int id) -{ - struct toptree *child; - - toptree_for_each_child(child, cand) - if (child->id == id) - return child; - child = toptree_alloc(cand->level-1, id); - toptree_insert(child, cand); - return child; -} - -/** - * toptree_first - Find the first descendant on specified level - * @context: Pointer to tree node whose descendants are to be used - * @level: The level of interest - * - * RETURNS: - * @context's first descendant on the specified level, or NULL - * if there is no matching descendant - */ -struct toptree *toptree_first(struct toptree *context, int level) -{ - struct toptree *child, *tmp; - - if (context->level == level) - return context; - - if (!list_empty(&context->children)) { - list_for_each_entry(child, &context->children, sibling) { - tmp = toptree_first(child, level); - if (tmp) - return tmp; - } - } - return NULL; -} - -/** - * toptree_next_sibling - Return next sibling - * @cur: Pointer to a tree node - * - * RETURNS: - * If @cur has a parent and is not the last in the parent's children list, - * the next sibling is returned. Or NULL when there are no siblings left. - */ -static struct toptree *toptree_next_sibling(struct toptree *cur) -{ - if (cur->parent == NULL) - return NULL; - - if (cur == list_last_entry(&cur->parent->children, - struct toptree, sibling)) - return NULL; - return (struct toptree *) list_next_entry(cur, sibling); -} - -/** - * toptree_next - Tree traversal function - * @cur: Pointer to current element - * @context: Pointer to the root node of the tree or subtree to - * be traversed. - * @level: The level of interest. - * - * RETURNS: - * Pointer to the next node on level @level - * or NULL when there is no next node. - */ -struct toptree *toptree_next(struct toptree *cur, struct toptree *context, - int level) -{ - struct toptree *cur_context, *tmp; - - if (!cur) - return NULL; - - if (context->level == level) - return NULL; - - tmp = toptree_next_sibling(cur); - if (tmp != NULL) - return tmp; - - cur_context = cur; - while (cur_context->level < context->level - 1) { - /* Step up */ - cur_context = cur_context->parent; - /* Step aside */ - tmp = toptree_next_sibling(cur_context); - if (tmp != NULL) { - /* Step down */ - tmp = toptree_first(tmp, level); - if (tmp != NULL) - return tmp; - } - } - return NULL; -} - -/** - * toptree_count - Count descendants on specified level - * @context: Pointer to node whose descendants are to be considered - * @level: Only descendants on the specified level will be counted - * - * RETURNS: - * Number of descendants on the specified level - */ -int toptree_count(struct toptree *context, int level) -{ - struct toptree *cur; - int cnt = 0; - - toptree_for_each(cur, context, level) - cnt++; - return cnt; -} |