// SPDX-License-Identifier: GPL-2.0-only
/*
 * call-path.h: Manipulate a tree data structure containing function call paths
 * Copyright (c) 2014, Intel Corporation.
 */

#include <linux/rbtree.h>
#include <linux/list.h>
#include <linux/zalloc.h>
#include <stdlib.h>

#include "call-path.h"

static void call_path__init(struct call_path *cp, struct call_path *parent,
                            struct symbol *sym, u64 ip, bool in_kernel)
{
        cp->parent = parent;
        cp->sym = sym;
        cp->ip = sym ? 0 : ip;
        cp->db_id = 0;
        cp->in_kernel = in_kernel;
        RB_CLEAR_NODE(&cp->rb_node);
        cp->children = RB_ROOT;
}

struct call_path_root *call_path_root__new(void)
{
        struct call_path_root *cpr;

        cpr = zalloc(sizeof(struct call_path_root));
        if (!cpr)
                return NULL;
        call_path__init(&cpr->call_path, NULL, NULL, 0, false);
        INIT_LIST_HEAD(&cpr->blocks);
        return cpr;
}

void call_path_root__free(struct call_path_root *cpr)
{
        struct call_path_block *pos, *n;

        list_for_each_entry_safe(pos, n, &cpr->blocks, node) {
                list_del_init(&pos->node);
                free(pos);
        }
        free(cpr);
}

static struct call_path *call_path__new(struct call_path_root *cpr,
                                        struct call_path *parent,
                                        struct symbol *sym, u64 ip,
                                        bool in_kernel)
{
        struct call_path_block *cpb;
        struct call_path *cp;
        size_t n;

        if (cpr->next < cpr->sz) {
                cpb = list_last_entry(&cpr->blocks, struct call_path_block,
                                      node);
        } else {
                cpb = zalloc(sizeof(struct call_path_block));
                if (!cpb)
                        return NULL;
                list_add_tail(&cpb->node, &cpr->blocks);
                cpr->sz += CALL_PATH_BLOCK_SIZE;
        }

        n = cpr->next++ & CALL_PATH_BLOCK_MASK;
        cp = &cpb->cp[n];

        call_path__init(cp, parent, sym, ip, in_kernel);

        return cp;
}

struct call_path *call_path__findnew(struct call_path_root *cpr,
                                     struct call_path *parent,
                                     struct symbol *sym, u64 ip, u64 ks)
{
        struct rb_node **p;
        struct rb_node *node_parent = NULL;
        struct call_path *cp;
        bool in_kernel = ip >= ks;

        if (sym)
                ip = 0;

        if (!parent)
                return call_path__new(cpr, parent, sym, ip, in_kernel);

        p = &parent->children.rb_node;
        while (*p != NULL) {
                node_parent = *p;
                cp = rb_entry(node_parent, struct call_path, rb_node);

                if (cp->sym == sym && cp->ip == ip)
                        return cp;

                if (sym < cp->sym || (sym == cp->sym && ip < cp->ip))
                        p = &(*p)->rb_left;
                else
                        p = &(*p)->rb_right;
        }

        cp = call_path__new(cpr, parent, sym, ip, in_kernel);
        if (!cp)
                return NULL;

        rb_link_node(&cp->rb_node, node_parent, p);
        rb_insert_color(&cp->rb_node, &parent->children);

        return cp;
}