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
 22static 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
 34struct 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
 46void 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
 57static 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
 85struct 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}