regs_access_pmccext_test.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright 2021, Athira Rajeev, 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 and
16 * sets MMCR0_PMCCEXT preventing further read access to the
17 * group B PMU registers.
18 */
19
20static int regs_access_pmccext(void)
21{
22	struct event event;
23
24	SKIP_IF(!ebb_is_supported());
25
26	event_init_named(&event, 0x1001e, "cycles");
27	event_leader_ebb_init(&event);
28
29	FAIL_IF(event_open(&event));
30
31	ebb_enable_pmc_counting(1);
32	setup_ebb_handler(standard_ebb_callee);
33	ebb_global_enable();
34	FAIL_IF(ebb_event_enable(&event));
35
36	mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
37
38	while (ebb_state.stats.ebb_count < 1)
39		FAIL_IF(core_busy_loop());
40
41	ebb_global_disable();
42	event_close(&event);
43
44	FAIL_IF(ebb_state.stats.ebb_count == 0);
45
46	/*
47	 * For ISA v3.1, verify the test takes a SIGILL when reading
48	 * PMU regs after the event is closed. With the control bit
49	 * in MMCR0 (PMCCEXT) restricting access to group B PMU regs,
50	 * sigill is expected.
51	 */
52	if (have_hwcap2(PPC_FEATURE2_ARCH_3_1))
53		FAIL_IF(catch_sigill(dump_ebb_state));
54	else
55		dump_ebb_state();
56
57	return 0;
58}
59
60int main(void)
61{
62	return test_harness(regs_access_pmccext, "regs_access_pmccext");
63}