kernel/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_mmcr2_test.c

   1 /*
   2  * Copyright 2014, Michael Ellerman, IBM Corp.
   3  * Licensed under GPLv2.
   4  */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <stdbool.h>
   9
  10 #include "ebb.h"
  11
  12
  13 /*
  14  * Test of counting cycles while manipulating the user accessible bits in MMCR2.
  15  */
  16
  17 /* We use two values because the first freezes PMC1 and so we would get no EBBs */
  18 #define MMCR2_EXPECTED_1 0x4020100804020000UL /* (FC1P|FC2P|FC3P|FC4P|FC5P|FC6P) */
  19 #define MMCR2_EXPECTED_2 0x0020100804020000UL /* (     FC2P|FC3P|FC4P|FC5P|FC6P) */
  20
  21
  22 int cycles_with_mmcr2(void)
  23 {
  24         struct event event;
  25         uint64_t val, expected[2], actual;
  26         int i;
  27         bool bad_mmcr2;
  28
  29         event_init_named(&event, 0x1001e, "cycles");
  30         event_leader_ebb_init(&event);
  31
  32         event.attr.exclude_kernel = 1;
  33         event.attr.exclude_hv = 1;
  34         event.attr.exclude_idle = 1;
  35
  36         FAIL_IF(event_open(&event));
  37
  38         ebb_enable_pmc_counting(1);
  39         setup_ebb_handler(standard_ebb_callee);
  40         ebb_global_enable();
  41
  42         FAIL_IF(ebb_event_enable(&event));
  43
  44         mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
  45
  46         /* XXX Set of MMCR2 must be after enable */
  47         expected[0] = MMCR2_EXPECTED_1;
  48         expected[1] = MMCR2_EXPECTED_2;
  49         i = 0;
  50         bad_mmcr2 = false;
  51
  52         /* Make sure we loop until we take at least one EBB */
  53         while ((ebb_state.stats.ebb_count < 20 && !bad_mmcr2) ||
  54                 ebb_state.stats.ebb_count < 1)
  55         {
  56                 mtspr(SPRN_MMCR2, expected[i % 2]);
  57
  58                 FAIL_IF(core_busy_loop());
  59
  60                 val = mfspr(SPRN_MMCR2);
  61                 if (val != expected[i % 2]) {
  62                         bad_mmcr2 = true;
  63                         actual = val;
  64                 }
  65
  66                 i++;
  67         }
  68
  69         ebb_global_disable();
  70         ebb_freeze_pmcs();
  71
  72         count_pmc(1, sample_period);
  73
  74         dump_ebb_state();
  75
  76         event_close(&event);
  77
  78         FAIL_IF(ebb_state.stats.ebb_count == 0);
  79
  80         if (bad_mmcr2)
  81                 printf("Bad MMCR2 value seen is 0x%lx\n", actual);
  82
  83         FAIL_IF(bad_mmcr2);
  84
  85         return 0;
  86 }
  87
  88 int main(void)
  89 {
  90         return test_harness(cycles_with_mmcr2, "cycles_with_mmcr2");
  91 }