143 lines · c
1// SPDX-License-Identifier: GPL-2.0+2 3/*4 * Copyright 2018 IBM Corporation.5 */6 7#define __SANE_USERSPACE_TYPES__8 9#include <sys/types.h>10#include <stdint.h>11#include <malloc.h>12#include <unistd.h>13#include <stdlib.h>14#include <string.h>15#include <stdio.h>16#include "utils.h"17#include "flush_utils.h"18 19 20int rfi_flush_test(void)21{22 char *p;23 int repetitions = 10;24 int fd, passes = 0, iter, rc = 0;25 struct perf_event_read v;26 __u64 l1d_misses_total = 0;27 unsigned long iterations = 100000, zero_size = 24 * 1024;28 unsigned long l1d_misses_expected;29 int rfi_flush_orig, rfi_flush;30 int have_entry_flush, entry_flush_orig;31 32 SKIP_IF(geteuid() != 0);33 34 // The PMU event we use only works on Power7 or later35 SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));36 37 if (read_debugfs_int("powerpc/rfi_flush", &rfi_flush_orig) < 0) {38 perror("Unable to read powerpc/rfi_flush debugfs file");39 SKIP_IF(1);40 }41 42 if (read_debugfs_int("powerpc/entry_flush", &entry_flush_orig) < 0) {43 have_entry_flush = 0;44 } else {45 have_entry_flush = 1;46 47 if (entry_flush_orig != 0) {48 if (write_debugfs_int("powerpc/entry_flush", 0) < 0) {49 perror("error writing to powerpc/entry_flush debugfs file");50 return 1;51 }52 }53 }54 55 rfi_flush = rfi_flush_orig;56 57 fd = perf_event_open_counter(PERF_TYPE_HW_CACHE, PERF_L1D_READ_MISS_CONFIG, -1);58 FAIL_IF(fd < 0);59 60 p = (char *)memalign(zero_size, CACHELINE_SIZE);61 62 FAIL_IF(perf_event_enable(fd));63 64 // disable L1 prefetching65 set_dscr(1);66 67 iter = repetitions;68 69 /*70 * We expect to see l1d miss for each cacheline access when rfi_flush71 * is set. Allow a small variation on this.72 */73 l1d_misses_expected = iterations * (zero_size / CACHELINE_SIZE - 2);74 75again:76 FAIL_IF(perf_event_reset(fd));77 78 syscall_loop(p, iterations, zero_size);79 80 FAIL_IF(read(fd, &v, sizeof(v)) != sizeof(v));81 82 if (rfi_flush && v.l1d_misses >= l1d_misses_expected)83 passes++;84 else if (!rfi_flush && v.l1d_misses < (l1d_misses_expected / 2))85 passes++;86 87 l1d_misses_total += v.l1d_misses;88 89 while (--iter)90 goto again;91 92 if (passes < repetitions) {93 printf("FAIL (L1D misses with rfi_flush=%d: %llu %c %lu) [%d/%d failures]\n",94 rfi_flush, l1d_misses_total, rfi_flush ? '<' : '>',95 rfi_flush ? repetitions * l1d_misses_expected :96 repetitions * l1d_misses_expected / 2,97 repetitions - passes, repetitions);98 rc = 1;99 } else100 printf("PASS (L1D misses with rfi_flush=%d: %llu %c %lu) [%d/%d pass]\n",101 rfi_flush, l1d_misses_total, rfi_flush ? '>' : '<',102 rfi_flush ? repetitions * l1d_misses_expected :103 repetitions * l1d_misses_expected / 2,104 passes, repetitions);105 106 if (rfi_flush == rfi_flush_orig) {107 rfi_flush = !rfi_flush_orig;108 if (write_debugfs_int("powerpc/rfi_flush", rfi_flush) < 0) {109 perror("error writing to powerpc/rfi_flush debugfs file");110 return 1;111 }112 iter = repetitions;113 l1d_misses_total = 0;114 passes = 0;115 goto again;116 }117 118 perf_event_disable(fd);119 close(fd);120 121 set_dscr(0);122 123 if (write_debugfs_int("powerpc/rfi_flush", rfi_flush_orig) < 0) {124 perror("unable to restore original value of powerpc/rfi_flush debugfs file");125 return 1;126 }127 128 if (have_entry_flush) {129 if (write_debugfs_int("powerpc/entry_flush", entry_flush_orig) < 0) {130 perror("unable to restore original value of powerpc/entry_flush "131 "debugfs file");132 return 1;133 }134 }135 136 return rc;137}138 139int main(int argc, char *argv[])140{141 return test_harness(rfi_flush_test, "rfi_flush_test");142}143