tools/testing/selftests/powerpc/pmu/ebb/ebb_vs_cpu_event_test.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2014, Michael Ellerman, IBM Corp.
   4  */
   5
   6 #include <signal.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <stdbool.h>
  10 #include <sys/types.h>
  11 #include <sys/wait.h>
  12 #include <unistd.h>
  13
  14 #include "ebb.h"
  15
  16
  17 /*
  18  * Tests an EBB vs a cpu event - in that order. The EBB should force the cpu
  19  * event off the PMU.
  20  */
  21
  22 static int setup_cpu_event(struct event *event, int cpu)
  23 {
  24         event_init_named(event, 0x400FA, "PM_RUN_INST_CMPL");
  25
  26         event->attr.exclude_kernel = 1;
  27         event->attr.exclude_hv = 1;
  28         event->attr.exclude_idle = 1;
  29
  30         SKIP_IF(require_paranoia_below(1));
  31         FAIL_IF(event_open_with_cpu(event, cpu));
  32         FAIL_IF(event_enable(event));
  33
  34         return 0;
  35 }
  36
  37 int ebb_vs_cpu_event(void)
  38 {
  39         union pipe read_pipe, write_pipe;
  40         struct event event;
  41         int cpu, rc;
  42         pid_t pid;
  43
  44         SKIP_IF(!ebb_is_supported());
  45
  46         cpu = pick_online_cpu();
  47         FAIL_IF(cpu < 0);
  48         FAIL_IF(bind_to_cpu(cpu));
  49
  50         FAIL_IF(pipe(read_pipe.fds) == -1);
  51         FAIL_IF(pipe(write_pipe.fds) == -1);
  52
  53         pid = fork();
  54         if (pid == 0) {
  55                 /* NB order of pipes looks reversed */
  56                 exit(ebb_child(write_pipe, read_pipe));
  57         }
  58
  59         /* Signal the child to install its EBB event and wait */
  60         FAIL_IF(sync_with_child(read_pipe, write_pipe));
  61
  62         /* Now try to install our CPU event */
  63         rc = setup_cpu_event(&event, cpu);
  64         if (rc) {
  65                 kill_child_and_wait(pid);
  66                 return rc;
  67         }
  68
  69         /* Signal the child to run */
  70         FAIL_IF(sync_with_child(read_pipe, write_pipe));
  71
  72         /* .. and wait for it to complete */
  73         FAIL_IF(wait_for_child(pid));
  74         FAIL_IF(event_disable(&event));
  75         FAIL_IF(event_read(&event));
  76
  77         event_report(&event);
  78
  79         /* The cpu event may have run, but we don't expect 100% */
  80         FAIL_IF(event.result.enabled >= event.result.running);
  81
  82         return 0;
  83 }
  84
  85 int main(void)
  86 {
  87         return test_harness(ebb_vs_cpu_event, "ebb_vs_cpu_event");
  88 }