1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2015, Michael Neuling, IBM Corp.
4 * Original: Michael Neuling 19/7/2013
5 * Edited: Rashmica Gupta 01/12/2015
6 *
7 * Do some transactions, see if the tar is corrupted.
8 * If the transaction is aborted, the TAR should be rolled back to the
9 * checkpointed value before the transaction began. The value written to
10 * TAR in suspended mode should only remain in TAR if the transaction
11 * completes.
12 */
13
14#include <stdio.h>
15#include <stdlib.h>
16#include <unistd.h>
17#include <string.h>
18
19#include "tm.h"
20#include "utils.h"
21
22int num_loops = 10000;
23
24int test_tar(void)
25{
26 int i;
27
28 SKIP_IF(!have_htm());
29 SKIP_IF(htm_is_synthetic());
30 SKIP_IF(!is_ppc64le());
31
32 for (i = 0; i < num_loops; i++)
33 {
34 uint64_t result = 0;
35 asm __volatile__(
36 "li 7, 1;"
37 "mtspr %[tar], 7;" /* tar = 1 */
38 "tbegin.;"
39 "beq 3f;"
40 "li 4, 0x7000;" /* Loop lots, to use time */
41 "2:;" /* Start loop */
42 "li 7, 2;"
43 "mtspr %[tar], 7;" /* tar = 2 */
44 "tsuspend.;"
45 "li 7, 3;"
46 "mtspr %[tar], 7;" /* tar = 3 */
47 "tresume.;"
48 "subi 4, 4, 1;"
49 "cmpdi 4, 0;"
50 "bne 2b;"
51 "tend.;"
52
53 /* Transaction sucess! TAR should be 3 */
54 "mfspr 7, %[tar];"
55 "ori %[res], 7, 4;" // res = 3|4 = 7
56 "b 4f;"
57
58 /* Abort handler. TAR should be rolled back to 1 */
59 "3:;"
60 "mfspr 7, %[tar];"
61 "ori %[res], 7, 8;" // res = 1|8 = 9
62 "4:;"
63
64 : [res]"=r"(result)
65 : [tar]"i"(SPRN_TAR)
66 : "memory", "r0", "r4", "r7");
67
68 /* If result is anything else other than 7 or 9, the tar
69 * value must have been corrupted. */
70 if ((result != 7) && (result != 9))
71 return 1;
72 }
73 return 0;
74}
75
76int main(int argc, char *argv[])
77{
78 /* A low number of iterations (eg 100) can cause a false pass */
79 if (argc > 1) {
80 if (strcmp(argv[1], "-h") == 0) {
81 printf("Syntax:\n\t%s [<num loops>]\n",
82 argv[0]);
83 return 1;
84 } else {
85 num_loops = atoi(argv[1]);
86 }
87 }
88
89 printf("Starting, %d loops\n", num_loops);
90
91 return test_harness(test_tar, "tm_tar");
92}
93

source code of linux/tools/testing/selftests/powerpc/tm/tm-tar.c