tools/testing/selftests/powerpc/tm/tm-tar.c

   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(!is_ppc64le());
  30
  31         for (i = 0; i < num_loops; i++)
  32         {
  33                 uint64_t result = 0;
  34                 asm __volatile__(
  35                         "li     7, 1;"
  36                         "mtspr  %[tar], 7;"     /* tar = 1 */
  37                         "tbegin.;"
  38                         "beq    3f;"
  39                         "li     4, 0x7000;"     /* Loop lots, to use time */
  40                         "2:;"                   /* Start loop */
  41                         "li     7, 2;"
  42                         "mtspr  %[tar], 7;"     /* tar = 2 */
  43                         "tsuspend.;"
  44                         "li     7, 3;"
  45                         "mtspr  %[tar], 7;"     /* tar = 3 */
  46                         "tresume.;"
  47                         "subi   4, 4, 1;"
  48                         "cmpdi  4, 0;"
  49                         "bne    2b;"
  50                         "tend.;"
  51
  52                         /* Transaction sucess! TAR should be 3 */
  53                         "mfspr  7, %[tar];"
  54                         "ori    %[res], 7, 4;"  // res = 3|4 = 7
  55                         "b      4f;"
  56
  57                         /* Abort handler. TAR should be rolled back to 1 */
  58                         "3:;"
  59                         "mfspr  7, %[tar];"
  60                         "ori    %[res], 7, 8;"  // res = 1|8 = 9
  61                         "4:;"
  62
  63                         : [res]"=r"(result)
  64                         : [tar]"i"(SPRN_TAR)
  65                            : "memory", "r0", "r4", "r7");
  66
  67                 /* If result is anything else other than 7 or 9, the tar
  68                  * value must have been corrupted. */
  69                 if ((result != 7) && (result != 9))
  70                         return 1;
  71         }
  72         return 0;
  73 }
  74
  75 int main(int argc, char *argv[])
  76 {
  77         /* A low number of iterations (eg 100) can cause a false pass */
  78         if (argc > 1) {
  79                 if (strcmp(argv[1], "-h") == 0) {
  80                         printf("Syntax:\n\t%s [<num loops>]\n",
  81                                argv[0]);
  82                         return 1;
  83                 } else {
  84                         num_loops = atoi(argv[1]);
  85                 }
  86         }
  87
  88         printf("Starting, %d loops\n", num_loops);
  89
  90         return test_harness(test_tar, "tm_tar");
  91 }