LXR linux/tools/testing/selftests/powerpc/pmu/ebb/cpu_event_vs_ebb

   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 a cpu event vs an EBB - in that order. The EBB should force the cpu
  19 * event off the PMU.
  20 */
  21
  22static 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
  37int 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        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        /* We setup the cpu event first */
  60        rc = setup_cpu_event(&event, cpu);
  61        if (rc) {
  62                kill_child_and_wait(pid);
  63                return rc;
  64        }
  65
  66        /* Signal the child to install its EBB event and wait */
  67        if (sync_with_child(read_pipe, write_pipe))
  68                /* If it fails, wait for it to exit */
  69                goto wait;
  70
  71        /* Signal the child to run */
  72        FAIL_IF(sync_with_child(read_pipe, write_pipe));
  73
  74wait:
  75        /* We expect the child to succeed */
  76        FAIL_IF(wait_for_child(pid));
  77
  78        FAIL_IF(event_disable(&event));
  79        FAIL_IF(event_read(&event));
  80
  81        event_report(&event);
  82
  83        /* The cpu event may have run */
  84
  85        return 0;
  86}
  87
  88int main(void)
  89{
  90        return test_harness(cpu_event_vs_ebb, "cpu_event_vs_ebb");
  91}
  92