1/*
2 * Copyright (c) 2013-2019, Intel Corporation
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 *  * Redistributions of source code must retain the above copyright notice,
8 *    this list of conditions and the following disclaimer.
9 *  * Redistributions in binary form must reproduce the above copyright notice,
10 *    this list of conditions and the following disclaimer in the documentation
11 *    and/or other materials provided with the distribution.
12 *  * Neither the name of Intel Corporation nor the names of its contributors
13 *    may be used to endorse or promote products derived from this software
14 *    without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef PT_TNT_CACHE_H
30#define PT_TNT_CACHE_H
31
32#include <stdint.h>
33
34struct pt_packet_tnt;
35struct pt_config;
36
37
38/* Keeping track of tnt indicators. */
39struct pt_tnt_cache {
40	/* The last tnt. */
41	uint64_t tnt;
42
43	/* The index into the above tnt.
44	 *
45	 * (tnt & index) gives the current tnt entry.
46	 * (index >>= 1) moves the index to the next tnt entry.
47	 * (index == 0) means that the current tnt is empty.
48	 */
49	uint64_t index;
50};
51
52
53/* Initialize (or reset) the tnt cache. */
54extern void pt_tnt_cache_init(struct pt_tnt_cache *cache);
55
56/* Check if the tnt cache is empty.
57 *
58 * Returns 0 if the tnt cache is not empty.
59 * Returns > 0 if the tnt cache is empty.
60 * Returns -pte_invalid if @cache is NULL.
61 */
62extern int pt_tnt_cache_is_empty(const struct pt_tnt_cache *cache);
63
64/* Query the next tnt indicator.
65 *
66 * This consumes the returned tnt indicator in the cache.
67 *
68 * Returns 0 if the next branch is not taken.
69 * Returns > 0 if the next branch is taken.
70 * Returns -pte_invalid if @cache is NULL.
71 * Returns -pte_bad_query if there is no tnt cached.
72 */
73extern int pt_tnt_cache_query(struct pt_tnt_cache *cache);
74
75/* Update the tnt cache based on Intel PT packets.
76 *
77 * Updates @cache based on @packet and, if non-null, @config.
78 *
79 * Returns zero on success.
80 * Returns -pte_invalid if @cache or @packet is NULL.
81 * Returns -pte_bad_packet if @packet appears to be corrupted.
82 * Returns -pte_bad_context if the tnt cache is not empty.
83 */
84extern int pt_tnt_cache_update_tnt(struct pt_tnt_cache *cache,
85				   const struct pt_packet_tnt *packet,
86				   const struct pt_config *config);
87
88#endif /* PT_TNT_CACHE_H */
89