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1// SPDX-License-Identifier: GPL-2.0+2 3/*4 * Copyright 2018 IBM Corporation.5 * Copyright 2020 Canonical Ltd.6 */7 8#define __SANE_USERSPACE_TYPES__9 10#include <sys/types.h>11#include <stdint.h>12#include <malloc.h>13#include <unistd.h>14#include <signal.h>15#include <stdlib.h>16#include <string.h>17#include <stdio.h>18#include "utils.h"19#include "flush_utils.h"20 21int uaccess_flush_test(void)22{23 char *p;24 int repetitions = 10;25 int fd, passes = 0, iter, rc = 0;26 struct perf_event_read v;27 __u64 l1d_misses_total = 0;28 unsigned long iterations = 100000, zero_size = 24 * 1024;29 unsigned long l1d_misses_expected;30 int rfi_flush_orig;31 int entry_flush_orig;32 int uaccess_flush, uaccess_flush_orig;33 34 SKIP_IF(geteuid() != 0);35 36 // The PMU event we use only works on Power7 or later37 SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));38 39 if (read_debugfs_int("powerpc/rfi_flush", &rfi_flush_orig) < 0) {40 perror("Unable to read powerpc/rfi_flush debugfs file");41 SKIP_IF(1);42 }43 44 if (read_debugfs_int("powerpc/entry_flush", &entry_flush_orig) < 0) {45 perror("Unable to read powerpc/entry_flush debugfs file");46 SKIP_IF(1);47 }48 49 if (read_debugfs_int("powerpc/uaccess_flush", &uaccess_flush_orig) < 0) {50 perror("Unable to read powerpc/entry_flush debugfs file");51 SKIP_IF(1);52 }53 54 if (rfi_flush_orig != 0) {55 if (write_debugfs_int("powerpc/rfi_flush", 0) < 0) {56 perror("error writing to powerpc/rfi_flush debugfs file");57 FAIL_IF(1);58 }59 }60 61 if (entry_flush_orig != 0) {62 if (write_debugfs_int("powerpc/entry_flush", 0) < 0) {63 perror("error writing to powerpc/entry_flush debugfs file");64 FAIL_IF(1);65 }66 }67 68 uaccess_flush = uaccess_flush_orig;69 70 fd = perf_event_open_counter(PERF_TYPE_HW_CACHE, PERF_L1D_READ_MISS_CONFIG, -1);71 FAIL_IF(fd < 0);72 73 p = (char *)memalign(zero_size, CACHELINE_SIZE);74 75 FAIL_IF(perf_event_enable(fd));76 77 // disable L1 prefetching78 set_dscr(1);79 80 iter = repetitions;81 82 /*83 * We expect to see l1d miss for each cacheline access when entry_flush84 * is set. Allow a small variation on this.85 */86 l1d_misses_expected = iterations * (zero_size / CACHELINE_SIZE - 2);87 88again:89 FAIL_IF(perf_event_reset(fd));90 91 syscall_loop_uaccess(p, iterations, zero_size);92 93 FAIL_IF(read(fd, &v, sizeof(v)) != sizeof(v));94 95 if (uaccess_flush && v.l1d_misses >= l1d_misses_expected)96 passes++;97 else if (!uaccess_flush && v.l1d_misses < (l1d_misses_expected / 2))98 passes++;99 100 l1d_misses_total += v.l1d_misses;101 102 while (--iter)103 goto again;104 105 if (passes < repetitions) {106 printf("FAIL (L1D misses with uaccess_flush=%d: %llu %c %lu) [%d/%d failures]\n",107 uaccess_flush, l1d_misses_total, uaccess_flush ? '<' : '>',108 uaccess_flush ? repetitions * l1d_misses_expected :109 repetitions * l1d_misses_expected / 2,110 repetitions - passes, repetitions);111 rc = 1;112 } else {113 printf("PASS (L1D misses with uaccess_flush=%d: %llu %c %lu) [%d/%d pass]\n",114 uaccess_flush, l1d_misses_total, uaccess_flush ? '>' : '<',115 uaccess_flush ? repetitions * l1d_misses_expected :116 repetitions * l1d_misses_expected / 2,117 passes, repetitions);118 }119 120 if (uaccess_flush == uaccess_flush_orig) {121 uaccess_flush = !uaccess_flush_orig;122 if (write_debugfs_int("powerpc/uaccess_flush", uaccess_flush) < 0) {123 perror("error writing to powerpc/uaccess_flush debugfs file");124 return 1;125 }126 iter = repetitions;127 l1d_misses_total = 0;128 passes = 0;129 goto again;130 }131 132 perf_event_disable(fd);133 close(fd);134 135 set_dscr(0);136 137 if (write_debugfs_int("powerpc/rfi_flush", rfi_flush_orig) < 0) {138 perror("unable to restore original value of powerpc/rfi_flush debugfs file");139 return 1;140 }141 142 if (write_debugfs_int("powerpc/entry_flush", entry_flush_orig) < 0) {143 perror("unable to restore original value of powerpc/entry_flush debugfs file");144 return 1;145 }146 147 if (write_debugfs_int("powerpc/uaccess_flush", uaccess_flush_orig) < 0) {148 perror("unable to restore original value of powerpc/uaccess_flush debugfs file");149 return 1;150 }151 152 return rc;153}154 155int main(int argc, char *argv[])156{157 return test_harness(uaccess_flush_test, "uaccess_flush_test");158}159