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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2023 Ventana Micro Systems Inc.
*
* Run with 'taskset -c <cpu-list> cbo' to only execute hwprobe on a
* subset of cpus, as well as only executing the tests on those cpus.
*/
#define _GNU_SOURCE
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <sched.h>
#include <signal.h>
#include <assert.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <asm/ucontext.h>
#include "hwprobe.h"
#include "../../kselftest.h"
#define MK_CBO(fn) cpu_to_le32((fn) << 20 | 10 << 15 | 2 << 12 | 0 << 7 | 15)
static char mem[4096] __aligned(4096) = { [0 ... 4095] = 0xa5 };
static bool illegal_insn;
static void sigill_handler(int sig, siginfo_t *info, void *context)
{
unsigned long *regs = (unsigned long *)&((ucontext_t *)context)->uc_mcontext;
uint32_t insn = *(uint32_t *)regs[0];
assert(insn == MK_CBO(regs[11]));
illegal_insn = true;
regs[0] += 4;
}
#define cbo_insn(base, fn) \
({ \
asm volatile( \
"mv a0, %0\n" \
"li a1, %1\n" \
".4byte %2\n" \
: : "r" (base), "i" (fn), "i" (MK_CBO(fn)) : "a0", "a1", "memory"); \
})
static void cbo_inval(char *base) { cbo_insn(base, 0); }
static void cbo_clean(char *base) { cbo_insn(base, 1); }
static void cbo_flush(char *base) { cbo_insn(base, 2); }
static void cbo_zero(char *base) { cbo_insn(base, 4); }
static void test_no_zicbom(void *arg)
{
ksft_print_msg("Testing Zicbom instructions remain privileged\n");
illegal_insn = false;
cbo_clean(&mem[0]);
ksft_test_result(illegal_insn, "No cbo.clean\n");
illegal_insn = false;
cbo_flush(&mem[0]);
ksft_test_result(illegal_insn, "No cbo.flush\n");
illegal_insn = false;
cbo_inval(&mem[0]);
ksft_test_result(illegal_insn, "No cbo.inval\n");
}
static void test_no_zicboz(void *arg)
{
ksft_print_msg("No Zicboz, testing cbo.zero remains privileged\n");
illegal_insn = false;
cbo_zero(&mem[0]);
ksft_test_result(illegal_insn, "No cbo.zero\n");
}
static bool is_power_of_2(__u64 n)
{
return n != 0 && (n & (n - 1)) == 0;
}
static void test_zicboz(void *arg)
{
struct riscv_hwprobe pair = {
.key = RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE,
};
cpu_set_t *cpus = (cpu_set_t *)arg;
__u64 block_size;
int i, j;
long rc;
rc = riscv_hwprobe(&pair, 1, sizeof(cpu_set_t), (unsigned long *)cpus, 0);
block_size = pair.value;
ksft_test_result(rc == 0 && pair.key == RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE &&
is_power_of_2(block_size), "Zicboz block size\n");
ksft_print_msg("Zicboz block size: %llu\n", block_size);
illegal_insn = false;
cbo_zero(&mem[block_size]);
ksft_test_result(!illegal_insn, "cbo.zero\n");
if (illegal_insn || !is_power_of_2(block_size)) {
ksft_test_result_skip("cbo.zero check\n");
return;
}
assert(block_size <= 1024);
for (i = 0; i < 4096 / block_size; ++i) {
if (i % 2)
cbo_zero(&mem[i * block_size]);
}
for (i = 0; i < 4096 / block_size; ++i) {
char expected = i % 2 ? 0x0 : 0xa5;
for (j = 0; j < block_size; ++j) {
if (mem[i * block_size + j] != expected) {
ksft_test_result_fail("cbo.zero check\n");
ksft_print_msg("cbo.zero check: mem[%llu] != 0x%x\n",
i * block_size + j, expected);
return;
}
}
}
ksft_test_result_pass("cbo.zero check\n");
}
static void check_no_zicboz_cpus(cpu_set_t *cpus)
{
struct riscv_hwprobe pair = {
.key = RISCV_HWPROBE_KEY_IMA_EXT_0,
};
cpu_set_t one_cpu;
int i = 0, c = 0;
long rc;
while (i++ < CPU_COUNT(cpus)) {
while (!CPU_ISSET(c, cpus))
++c;
CPU_ZERO(&one_cpu);
CPU_SET(c, &one_cpu);
rc = riscv_hwprobe(&pair, 1, sizeof(cpu_set_t), (unsigned long *)&one_cpu, 0);
assert(rc == 0 && pair.key == RISCV_HWPROBE_KEY_IMA_EXT_0);
if (pair.value & RISCV_HWPROBE_EXT_ZICBOZ)
ksft_exit_fail_msg("Zicboz is only present on a subset of harts.\n"
"Use taskset to select a set of harts where Zicboz\n"
"presence (present or not) is consistent for each hart\n");
++c;
}
}
enum {
TEST_ZICBOZ,
TEST_NO_ZICBOZ,
TEST_NO_ZICBOM,
};
static struct test_info {
bool enabled;
unsigned int nr_tests;
void (*test_fn)(void *arg);
} tests[] = {
[TEST_ZICBOZ] = { .nr_tests = 3, test_zicboz },
[TEST_NO_ZICBOZ] = { .nr_tests = 1, test_no_zicboz },
[TEST_NO_ZICBOM] = { .nr_tests = 3, test_no_zicbom },
};
int main(int argc, char **argv)
{
struct sigaction act = {
.sa_sigaction = &sigill_handler,
.sa_flags = SA_SIGINFO,
};
struct riscv_hwprobe pair;
unsigned int plan = 0;
cpu_set_t cpus;
long rc;
int i;
if (argc > 1 && !strcmp(argv[1], "--sigill")) {
rc = sigaction(SIGILL, &act, NULL);
assert(rc == 0);
tests[TEST_NO_ZICBOZ].enabled = true;
tests[TEST_NO_ZICBOM].enabled = true;
}
rc = sched_getaffinity(0, sizeof(cpu_set_t), &cpus);
assert(rc == 0);
ksft_print_header();
pair.key = RISCV_HWPROBE_KEY_IMA_EXT_0;
rc = riscv_hwprobe(&pair, 1, sizeof(cpu_set_t), (unsigned long *)&cpus, 0);
if (rc < 0)
ksft_exit_fail_msg("hwprobe() failed with %ld\n", rc);
assert(rc == 0 && pair.key == RISCV_HWPROBE_KEY_IMA_EXT_0);
if (pair.value & RISCV_HWPROBE_EXT_ZICBOZ) {
tests[TEST_ZICBOZ].enabled = true;
tests[TEST_NO_ZICBOZ].enabled = false;
} else {
check_no_zicboz_cpus(&cpus);
}
for (i = 0; i < ARRAY_SIZE(tests); ++i)
plan += tests[i].enabled ? tests[i].nr_tests : 0;
if (plan == 0)
ksft_print_msg("No tests enabled.\n");
else
ksft_set_plan(plan);
for (i = 0; i < ARRAY_SIZE(tests); ++i) {
if (tests[i].enabled)
tests[i].test_fn(&cpus);
}
ksft_finished();
}
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