xref: /linux/tools/testing/selftests/powerpc/tm/tm-tar.c (revision 6c8c1406a6d6a3f2e61ac590f5c0994231bc6be7)
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 
22 int	num_loops	= 10000;
23 
24 int 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 
76 int 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