1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2023 Ventana Micro Systems Inc. 4 * 5 * Run with 'taskset -c <cpu-list> cbo' to only execute hwprobe on a 6 * subset of cpus, as well as only executing the tests on those cpus. 7 */ 8 #define _GNU_SOURCE 9 #include <stdbool.h> 10 #include <stdint.h> 11 #include <string.h> 12 #include <sched.h> 13 #include <signal.h> 14 #include <assert.h> 15 #include <linux/compiler.h> 16 #include <linux/kernel.h> 17 #include <asm/ucontext.h> 18 19 #include "hwprobe.h" 20 #include "../../kselftest.h" 21 22 #define MK_CBO(fn) cpu_to_le32((fn) << 20 | 10 << 15 | 2 << 12 | 0 << 7 | 15) 23 24 static char mem[4096] __aligned(4096) = { [0 ... 4095] = 0xa5 }; 25 26 static bool illegal_insn; 27 28 static void sigill_handler(int sig, siginfo_t *info, void *context) 29 { 30 unsigned long *regs = (unsigned long *)&((ucontext_t *)context)->uc_mcontext; 31 uint32_t insn = *(uint32_t *)regs[0]; 32 33 assert(insn == MK_CBO(regs[11])); 34 35 illegal_insn = true; 36 regs[0] += 4; 37 } 38 39 #define cbo_insn(base, fn) \ 40 ({ \ 41 asm volatile( \ 42 "mv a0, %0\n" \ 43 "li a1, %1\n" \ 44 ".4byte %2\n" \ 45 : : "r" (base), "i" (fn), "i" (MK_CBO(fn)) : "a0", "a1", "memory"); \ 46 }) 47 48 static void cbo_inval(char *base) { cbo_insn(base, 0); } 49 static void cbo_clean(char *base) { cbo_insn(base, 1); } 50 static void cbo_flush(char *base) { cbo_insn(base, 2); } 51 static void cbo_zero(char *base) { cbo_insn(base, 4); } 52 53 static void test_no_zicbom(void *arg) 54 { 55 ksft_print_msg("Testing Zicbom instructions remain privileged\n"); 56 57 illegal_insn = false; 58 cbo_clean(&mem[0]); 59 ksft_test_result(illegal_insn, "No cbo.clean\n"); 60 61 illegal_insn = false; 62 cbo_flush(&mem[0]); 63 ksft_test_result(illegal_insn, "No cbo.flush\n"); 64 65 illegal_insn = false; 66 cbo_inval(&mem[0]); 67 ksft_test_result(illegal_insn, "No cbo.inval\n"); 68 } 69 70 static void test_no_zicboz(void *arg) 71 { 72 ksft_print_msg("No Zicboz, testing cbo.zero remains privileged\n"); 73 74 illegal_insn = false; 75 cbo_zero(&mem[0]); 76 ksft_test_result(illegal_insn, "No cbo.zero\n"); 77 } 78 79 static bool is_power_of_2(__u64 n) 80 { 81 return n != 0 && (n & (n - 1)) == 0; 82 } 83 84 static void test_zicboz(void *arg) 85 { 86 struct riscv_hwprobe pair = { 87 .key = RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE, 88 }; 89 cpu_set_t *cpus = (cpu_set_t *)arg; 90 __u64 block_size; 91 int i, j; 92 long rc; 93 94 rc = riscv_hwprobe(&pair, 1, sizeof(cpu_set_t), (unsigned long *)cpus, 0); 95 block_size = pair.value; 96 ksft_test_result(rc == 0 && pair.key == RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE && 97 is_power_of_2(block_size), "Zicboz block size\n"); 98 ksft_print_msg("Zicboz block size: %llu\n", block_size); 99 100 illegal_insn = false; 101 cbo_zero(&mem[block_size]); 102 ksft_test_result(!illegal_insn, "cbo.zero\n"); 103 104 if (illegal_insn || !is_power_of_2(block_size)) { 105 ksft_test_result_skip("cbo.zero check\n"); 106 return; 107 } 108 109 assert(block_size <= 1024); 110 111 for (i = 0; i < 4096 / block_size; ++i) { 112 if (i % 2) 113 cbo_zero(&mem[i * block_size]); 114 } 115 116 for (i = 0; i < 4096 / block_size; ++i) { 117 char expected = i % 2 ? 0x0 : 0xa5; 118 119 for (j = 0; j < block_size; ++j) { 120 if (mem[i * block_size + j] != expected) { 121 ksft_test_result_fail("cbo.zero check\n"); 122 ksft_print_msg("cbo.zero check: mem[%llu] != 0x%x\n", 123 i * block_size + j, expected); 124 return; 125 } 126 } 127 } 128 129 ksft_test_result_pass("cbo.zero check\n"); 130 } 131 132 static void check_no_zicboz_cpus(cpu_set_t *cpus) 133 { 134 struct riscv_hwprobe pair = { 135 .key = RISCV_HWPROBE_KEY_IMA_EXT_0, 136 }; 137 cpu_set_t one_cpu; 138 int i = 0, c = 0; 139 long rc; 140 141 while (i++ < CPU_COUNT(cpus)) { 142 while (!CPU_ISSET(c, cpus)) 143 ++c; 144 145 CPU_ZERO(&one_cpu); 146 CPU_SET(c, &one_cpu); 147 148 rc = riscv_hwprobe(&pair, 1, sizeof(cpu_set_t), (unsigned long *)&one_cpu, 0); 149 assert(rc == 0 && pair.key == RISCV_HWPROBE_KEY_IMA_EXT_0); 150 151 if (pair.value & RISCV_HWPROBE_EXT_ZICBOZ) 152 ksft_exit_fail_msg("Zicboz is only present on a subset of harts.\n" 153 "Use taskset to select a set of harts where Zicboz\n" 154 "presence (present or not) is consistent for each hart\n"); 155 ++c; 156 } 157 } 158 159 enum { 160 TEST_ZICBOZ, 161 TEST_NO_ZICBOZ, 162 TEST_NO_ZICBOM, 163 }; 164 165 static struct test_info { 166 bool enabled; 167 unsigned int nr_tests; 168 void (*test_fn)(void *arg); 169 } tests[] = { 170 [TEST_ZICBOZ] = { .nr_tests = 3, test_zicboz }, 171 [TEST_NO_ZICBOZ] = { .nr_tests = 1, test_no_zicboz }, 172 [TEST_NO_ZICBOM] = { .nr_tests = 3, test_no_zicbom }, 173 }; 174 175 int main(int argc, char **argv) 176 { 177 struct sigaction act = { 178 .sa_sigaction = &sigill_handler, 179 .sa_flags = SA_SIGINFO, 180 }; 181 struct riscv_hwprobe pair; 182 unsigned int plan = 0; 183 cpu_set_t cpus; 184 long rc; 185 int i; 186 187 if (argc > 1 && !strcmp(argv[1], "--sigill")) { 188 rc = sigaction(SIGILL, &act, NULL); 189 assert(rc == 0); 190 tests[TEST_NO_ZICBOZ].enabled = true; 191 tests[TEST_NO_ZICBOM].enabled = true; 192 } 193 194 rc = sched_getaffinity(0, sizeof(cpu_set_t), &cpus); 195 assert(rc == 0); 196 197 ksft_print_header(); 198 199 pair.key = RISCV_HWPROBE_KEY_IMA_EXT_0; 200 rc = riscv_hwprobe(&pair, 1, sizeof(cpu_set_t), (unsigned long *)&cpus, 0); 201 if (rc < 0) 202 ksft_exit_fail_msg("hwprobe() failed with %ld\n", rc); 203 assert(rc == 0 && pair.key == RISCV_HWPROBE_KEY_IMA_EXT_0); 204 205 if (pair.value & RISCV_HWPROBE_EXT_ZICBOZ) { 206 tests[TEST_ZICBOZ].enabled = true; 207 tests[TEST_NO_ZICBOZ].enabled = false; 208 } else { 209 check_no_zicboz_cpus(&cpus); 210 } 211 212 for (i = 0; i < ARRAY_SIZE(tests); ++i) 213 plan += tests[i].enabled ? tests[i].nr_tests : 0; 214 215 if (plan == 0) 216 ksft_print_msg("No tests enabled.\n"); 217 else 218 ksft_set_plan(plan); 219 220 for (i = 0; i < ARRAY_SIZE(tests); ++i) { 221 if (tests[i].enabled) 222 tests[i].test_fn(&cpus); 223 } 224 225 ksft_finished(); 226 } 227