1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2014, Michael Ellerman, IBM Corp.
4 */
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <setjmp.h>
9#include <signal.h>
10
11#include "ebb.h"
12
13
14/*
15 * Test that closing the EBB event clears MMCR0_PMCC, preventing further access
16 * by userspace to the PMU hardware.
17 */
18
19int close_clears_pmcc(void)
20{
21 struct event event;
22
23 SKIP_IF(!ebb_is_supported());
24
25 event_init_named(e: &event, config: 0x1001e, name: "cycles");
26 event_leader_ebb_init(e: &event);
27
28 FAIL_IF(event_open(e: &event));
29
30 ebb_enable_pmc_counting(pmc: 1);
31 setup_ebb_handler(standard_ebb_callee);
32 ebb_global_enable();
33 FAIL_IF(ebb_event_enable(e: &event));
34
35 mtspr(SPRN_PMC1, pmc_sample_period(value: sample_period));
36
37 while (ebb_state.stats.ebb_count < 1)
38 FAIL_IF(core_busy_loop());
39
40 ebb_global_disable();
41 event_close(e: &event);
42
43 FAIL_IF(ebb_state.stats.ebb_count == 0);
44
45 /* The real test is here, do we take a SIGILL when writing PMU regs now
46 * that we have closed the event. We expect that we will. */
47
48 FAIL_IF(catch_sigill(func: write_pmc1));
49
50 /* We should still be able to read EBB regs though */
51 mfspr(SPRN_EBBHR);
52 mfspr(SPRN_EBBRR);
53 mfspr(SPRN_BESCR);
54
55 return 0;
56}
57
58int main(void)
59{
60 return test_harness(close_clears_pmcc, "close_clears_pmcc");
61}
62

source code of linux/tools/testing/selftests/powerpc/pmu/ebb/close_clears_pmcc_test.c