kernel/tools/testing/selftests/powerpc/pmu/ebb/cpu_event_pinned_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 pinned cpu event vs an EBB - in that order. The pinned cpu event
  19  * should remain and the EBB event should fail to enable.
  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.pinned = 1;
  27
  28         event->attr.exclude_kernel = 1;
  29         event->attr.exclude_hv = 1;
  30         event->attr.exclude_idle = 1;
  31
  32         SKIP_IF(require_paranoia_below(1));
  33         FAIL_IF(event_open_with_cpu(event, cpu));
  34         FAIL_IF(event_enable(event));
  35
  36         return 0;
  37 }
  38
  39 int cpu_event_pinned_vs_ebb(void)
  40 {
  41         union pipe read_pipe, write_pipe;
  42         struct event event;
  43         int cpu, rc;
  44         pid_t pid;
  45
  46         SKIP_IF(!ebb_is_supported());
  47
  48         cpu = pick_online_cpu();
  49         FAIL_IF(cpu < 0);
  50         FAIL_IF(bind_to_cpu(cpu));
  51
  52         FAIL_IF(pipe(read_pipe.fds) == -1);
  53         FAIL_IF(pipe(write_pipe.fds) == -1);
  54
  55         pid = fork();
  56         if (pid == 0) {
  57                 /* NB order of pipes looks reversed */
  58                 exit(ebb_child(write_pipe, read_pipe));
  59         }
  60
  61         /* We setup the cpu event first */
  62         rc = setup_cpu_event(&event, cpu);
  63         if (rc) {
  64                 kill_child_and_wait(pid);
  65                 return rc;
  66         }
  67
  68         /* Signal the child to install its EBB event and wait */
  69         if (sync_with_child(read_pipe, write_pipe))
  70                 /* If it fails, wait for it to exit */
  71                 goto wait;
  72
  73         /* Signal the child to run */
  74         FAIL_IF(sync_with_child(read_pipe, write_pipe));
  75
  76 wait:
  77         /* We expect it to fail to read the event */
  78         FAIL_IF(wait_for_child(pid) != 2);
  79
  80         FAIL_IF(event_disable(&event));
  81         FAIL_IF(event_read(&event));
  82
  83         event_report(&event);
  84
  85         /* The cpu event should have run */
  86         FAIL_IF(event.result.value == 0);
  87         FAIL_IF(event.result.enabled != event.result.running);
  88
  89         return 0;
  90 }
  91
  92 int main(void)
  93 {
  94         return test_harness(cpu_event_pinned_vs_ebb, "cpu_event_pinned_vs_ebb");
  95 }