xref: /openbmc/linux/tools/perf/util/call-path.c (revision feac8c8b)
1 /*
2  * call-path.h: Manipulate a tree data structure containing function call paths
3  * Copyright (c) 2014, Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  */
15 
16 #include <linux/rbtree.h>
17 #include <linux/list.h>
18 
19 #include "util.h"
20 #include "call-path.h"
21 
22 static void call_path__init(struct call_path *cp, struct call_path *parent,
23 			    struct symbol *sym, u64 ip, bool in_kernel)
24 {
25 	cp->parent = parent;
26 	cp->sym = sym;
27 	cp->ip = sym ? 0 : ip;
28 	cp->db_id = 0;
29 	cp->in_kernel = in_kernel;
30 	RB_CLEAR_NODE(&cp->rb_node);
31 	cp->children = RB_ROOT;
32 }
33 
34 struct call_path_root *call_path_root__new(void)
35 {
36 	struct call_path_root *cpr;
37 
38 	cpr = zalloc(sizeof(struct call_path_root));
39 	if (!cpr)
40 		return NULL;
41 	call_path__init(&cpr->call_path, NULL, NULL, 0, false);
42 	INIT_LIST_HEAD(&cpr->blocks);
43 	return cpr;
44 }
45 
46 void call_path_root__free(struct call_path_root *cpr)
47 {
48 	struct call_path_block *pos, *n;
49 
50 	list_for_each_entry_safe(pos, n, &cpr->blocks, node) {
51 		list_del(&pos->node);
52 		free(pos);
53 	}
54 	free(cpr);
55 }
56 
57 static struct call_path *call_path__new(struct call_path_root *cpr,
58 					struct call_path *parent,
59 					struct symbol *sym, u64 ip,
60 					bool in_kernel)
61 {
62 	struct call_path_block *cpb;
63 	struct call_path *cp;
64 	size_t n;
65 
66 	if (cpr->next < cpr->sz) {
67 		cpb = list_last_entry(&cpr->blocks, struct call_path_block,
68 				      node);
69 	} else {
70 		cpb = zalloc(sizeof(struct call_path_block));
71 		if (!cpb)
72 			return NULL;
73 		list_add_tail(&cpb->node, &cpr->blocks);
74 		cpr->sz += CALL_PATH_BLOCK_SIZE;
75 	}
76 
77 	n = cpr->next++ & CALL_PATH_BLOCK_MASK;
78 	cp = &cpb->cp[n];
79 
80 	call_path__init(cp, parent, sym, ip, in_kernel);
81 
82 	return cp;
83 }
84 
85 struct call_path *call_path__findnew(struct call_path_root *cpr,
86 				     struct call_path *parent,
87 				     struct symbol *sym, u64 ip, u64 ks)
88 {
89 	struct rb_node **p;
90 	struct rb_node *node_parent = NULL;
91 	struct call_path *cp;
92 	bool in_kernel = ip >= ks;
93 
94 	if (sym)
95 		ip = 0;
96 
97 	if (!parent)
98 		return call_path__new(cpr, parent, sym, ip, in_kernel);
99 
100 	p = &parent->children.rb_node;
101 	while (*p != NULL) {
102 		node_parent = *p;
103 		cp = rb_entry(node_parent, struct call_path, rb_node);
104 
105 		if (cp->sym == sym && cp->ip == ip)
106 			return cp;
107 
108 		if (sym < cp->sym || (sym == cp->sym && ip < cp->ip))
109 			p = &(*p)->rb_left;
110 		else
111 			p = &(*p)->rb_right;
112 	}
113 
114 	cp = call_path__new(cpr, parent, sym, ip, in_kernel);
115 	if (!cp)
116 		return NULL;
117 
118 	rb_link_node(&cp->rb_node, node_parent, p);
119 	rb_insert_color(&cp->rb_node, &parent->children);
120 
121 	return cp;
122 }
123