cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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cycles_with_mmcr2_test.c (1837B)

      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 <stdbool.h>
      9
     10#include "ebb.h"
     11
     12
     13/*
     14 * Test of counting cycles while manipulating the user accessible bits in MMCR2.
     15 */
     16
     17/* We use two values because the first freezes PMC1 and so we would get no EBBs */
     18#define MMCR2_EXPECTED_1 0x4020100804020000UL /* (FC1P|FC2P|FC3P|FC4P|FC5P|FC6P) */
     19#define MMCR2_EXPECTED_2 0x0020100804020000UL /* (     FC2P|FC3P|FC4P|FC5P|FC6P) */
     20
     21
     22int cycles_with_mmcr2(void)
     23{
     24	struct event event;
     25	uint64_t val, expected[2], actual;
     26	int i;
     27	bool bad_mmcr2;
     28
     29	SKIP_IF(!ebb_is_supported());
     30
     31	event_init_named(&event, 0x1001e, "cycles");
     32	event_leader_ebb_init(&event);
     33
     34	event.attr.exclude_kernel = 1;
     35	event.attr.exclude_hv = 1;
     36	event.attr.exclude_idle = 1;
     37
     38	FAIL_IF(event_open(&event));
     39
     40	ebb_enable_pmc_counting(1);
     41	setup_ebb_handler(standard_ebb_callee);
     42	ebb_global_enable();
     43
     44	FAIL_IF(ebb_event_enable(&event));
     45
     46	mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
     47
     48	/* XXX Set of MMCR2 must be after enable */
     49	expected[0] = MMCR2_EXPECTED_1;
     50	expected[1] = MMCR2_EXPECTED_2;
     51	i = 0;
     52	bad_mmcr2 = false;
     53
     54	/* Make sure we loop until we take at least one EBB */
     55	while ((ebb_state.stats.ebb_count < 20 && !bad_mmcr2) ||
     56		ebb_state.stats.ebb_count < 1)
     57	{
     58		mtspr(SPRN_MMCR2, expected[i % 2]);
     59
     60		FAIL_IF(core_busy_loop());
     61
     62		val = mfspr(SPRN_MMCR2);
     63		if (val != expected[i % 2]) {
     64			bad_mmcr2 = true;
     65			actual = val;
     66		}
     67
     68		i++;
     69	}
     70
     71	ebb_global_disable();
     72	ebb_freeze_pmcs();
     73
     74	dump_ebb_state();
     75
     76	event_close(&event);
     77
     78	FAIL_IF(ebb_state.stats.ebb_count == 0);
     79
     80	if (bad_mmcr2)
     81		printf("Bad MMCR2 value seen is 0x%lx\n", actual);
     82
     83	FAIL_IF(bad_mmcr2);
     84
     85	return 0;
     86}
     87
     88int main(void)
     89{
     90	return test_harness(cycles_with_mmcr2, "cycles_with_mmcr2");
     91}