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      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 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 }
     89