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

   1 /*
   2  * Copyright 2014, Michael Ellerman, IBM Corp.
   3  * Licensed under GPLv2.
   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 a cpu event vs an EBB - 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 cpu_event_vs_ebb(void)
  38 {
  39         union pipe read_pipe, write_pipe;
  40         struct event event;
  41         int cpu, rc;
  42         pid_t pid;
  43
  44         cpu = pick_online_cpu();
  45         FAIL_IF(cpu < 0);
  46         FAIL_IF(bind_to_cpu(cpu));
  47
  48         FAIL_IF(pipe(read_pipe.fds) == -1);
  49         FAIL_IF(pipe(write_pipe.fds) == -1);
  50
  51         pid = fork();
  52         if (pid == 0) {
  53                 /* NB order of pipes looks reversed */
  54                 exit(ebb_child(write_pipe, read_pipe));
  55         }
  56
  57         /* We setup the cpu event first */
  58         rc = setup_cpu_event(&event, cpu);
  59         if (rc) {
  60                 kill_child_and_wait(pid);
  61                 return rc;
  62         }
  63
  64         /* Signal the child to install its EBB event and wait */
  65         if (sync_with_child(read_pipe, write_pipe))
  66                 /* If it fails, wait for it to exit */
  67                 goto wait;
  68
  69         /* Signal the child to run */
  70         FAIL_IF(sync_with_child(read_pipe, write_pipe));
  71
  72 wait:
  73         /* We expect the child to succeed */
  74         FAIL_IF(wait_for_child(pid));
  75
  76         FAIL_IF(event_disable(&event));
  77         FAIL_IF(event_read(&event));
  78
  79         event_report(&event);
  80
  81         /* The cpu event may have run */
  82
  83         return 0;
  84 }
  85
  86 int main(void)
  87 {
  88         return test_harness(cpu_event_vs_ebb, "cpu_event_vs_ebb");
  89 }