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}
115