1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * call-path.h: Manipulate a tree data structure containing function call paths
  4 * Copyright (c) 2014, Intel Corporation.
  5 */
  6
  7#include <linux/rbtree.h>
  8#include <linux/list.h>
  9#include <linux/zalloc.h>
 10#include <stdlib.h>
 11
 12#include "call-path.h"
 13
 14static void call_path__init(struct call_path *cp, struct call_path *parent,
 15			    struct symbol *sym, u64 ip, bool in_kernel)
 16{
 17	cp->parent = parent;
 18	cp->sym = sym;
 19	cp->ip = sym ? 0 : ip;
 20	cp->db_id = 0;
 21	cp->in_kernel = in_kernel;
 22	RB_CLEAR_NODE(&cp->rb_node);
 23	cp->children = RB_ROOT;
 24}
 25
 26struct call_path_root *call_path_root__new(void)
 27{
 28	struct call_path_root *cpr;
 29
 30	cpr = zalloc(sizeof(struct call_path_root));
 31	if (!cpr)
 32		return NULL;
 33	call_path__init(&cpr->call_path, NULL, NULL, 0, false);
 34	INIT_LIST_HEAD(&cpr->blocks);
 35	return cpr;
 36}
 37
 38void call_path_root__free(struct call_path_root *cpr)
 39{
 40	struct call_path_block *pos, *n;
 41
 42	list_for_each_entry_safe(pos, n, &cpr->blocks, node) {
 43		list_del_init(&pos->node);
 44		free(pos);
 45	}
 46	free(cpr);
 47}
 48
 49static struct call_path *call_path__new(struct call_path_root *cpr,
 50					struct call_path *parent,
 51					struct symbol *sym, u64 ip,
 52					bool in_kernel)
 53{
 54	struct call_path_block *cpb;
 55	struct call_path *cp;
 56	size_t n;
 57
 58	if (cpr->next < cpr->sz) {
 59		cpb = list_last_entry(&cpr->blocks, struct call_path_block,
 60				      node);
 61	} else {
 62		cpb = zalloc(sizeof(struct call_path_block));
 63		if (!cpb)
 64			return NULL;
 65		list_add_tail(&cpb->node, &cpr->blocks);
 66		cpr->sz += CALL_PATH_BLOCK_SIZE;
 67	}
 68
 69	n = cpr->next++ & CALL_PATH_BLOCK_MASK;
 70	cp = &cpb->cp[n];
 71
 72	call_path__init(cp, parent, sym, ip, in_kernel);
 73
 74	return cp;
 75}
 76
 77struct call_path *call_path__findnew(struct call_path_root *cpr,
 78				     struct call_path *parent,
 79				     struct symbol *sym, u64 ip, u64 ks)
 80{
 81	struct rb_node **p;
 82	struct rb_node *node_parent = NULL;
 83	struct call_path *cp;
 84	bool in_kernel = ip >= ks;
 85
 86	if (sym)
 87		ip = 0;
 88
 89	if (!parent)
 90		return call_path__new(cpr, parent, sym, ip, in_kernel);
 91
 92	p = &parent->children.rb_node;
 93	while (*p != NULL) {
 94		node_parent = *p;
 95		cp = rb_entry(node_parent, struct call_path, rb_node);
 96
 97		if (cp->sym == sym && cp->ip == ip)
 98			return cp;
 99
100		if (sym < cp->sym || (sym == cp->sym && ip < cp->ip))
101			p = &(*p)->rb_left;
102		else
103			p = &(*p)->rb_right;
104	}
105
106	cp = call_path__new(cpr, parent, sym, ip, in_kernel);
107	if (!cp)
108		return NULL;
109
110	rb_link_node(&cp->rb_node, node_parent, p);
111	rb_insert_color(&cp->rb_node, &parent->children);
112
113	return cp;
114}