--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022 ARM Limited.
+ */
+
+#define _GNU_SOURCE
+#define _POSIX_C_SOURCE 199309L
+
+#include <errno.h>
+#include <getopt.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/auxv.h>
+#include <sys/epoll.h>
+#include <sys/prctl.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/wait.h>
+#include <asm/hwcap.h>
+
+#include "../../kselftest.h"
+
+#define MAX_VLS 16
+
+struct child_data {
+ char *name, *output;
+ pid_t pid;
+ int stdout;
+ bool output_seen;
+ bool exited;
+ int exit_status;
+};
+
+static int epoll_fd;
+static struct child_data *children;
+static int num_children;
+static bool terminate;
+
+static void drain_output(bool flush);
+
+static int num_processors(void)
+{
+ long nproc = sysconf(_SC_NPROCESSORS_CONF);
+ if (nproc < 0) {
+ perror("Unable to read number of processors\n");
+ exit(EXIT_FAILURE);
+ }
+
+ return nproc;
+}
+
+static void child_start(struct child_data *child, const char *program)
+{
+ int ret, pipefd[2], i;
+ struct epoll_event ev;
+
+ ret = pipe(pipefd);
+ if (ret != 0)
+ ksft_exit_fail_msg("Failed to create stdout pipe: %s (%d)\n",
+ strerror(errno), errno);
+
+ child->pid = fork();
+ if (child->pid == -1)
+ ksft_exit_fail_msg("fork() failed: %s (%d)\n",
+ strerror(errno), errno);
+
+ if (!child->pid) {
+ /*
+ * In child, replace stdout with the pipe, errors to
+ * stderr from here as kselftest prints to stdout.
+ */
+ ret = dup2(pipefd[1], 1);
+ if (ret == -1) {
+ fprintf(stderr, "dup2() %d\n", errno);
+ exit(EXIT_FAILURE);
+ }
+
+ /*
+ * Very dumb mechanism to clean open FDs other than
+ * stdio. We don't want O_CLOEXEC for the pipes...
+ */
+ for (i = 3; i < 8192; i++)
+ close(i);
+
+ ret = execl(program, program, NULL);
+ fprintf(stderr, "execl(%s) failed: %d (%s)\n",
+ program, errno, strerror(errno));
+
+ exit(EXIT_FAILURE);
+ } else {
+ /*
+ * In parent, remember the child and close our copy of the
+ * write side of stdout.
+ */
+ close(pipefd[1]);
+ child->stdout = pipefd[0];
+ child->output = NULL;
+ child->exited = false;
+ child->output_seen = false;
+
+ ev.events = EPOLLIN | EPOLLHUP;
+ ev.data.ptr = child;
+
+ ret = epoll_ctl(epoll_fd, EPOLL_CTL_ADD, child->stdout, &ev);
+ if (ret < 0) {
+ ksft_exit_fail_msg("%s EPOLL_CTL_ADD failed: %s (%d)\n",
+ child->name, strerror(errno), errno);
+ }
+
+ /*
+ * Keep output flowing during child startup so logs
+ * are more timely, can help debugging.
+ */
+ drain_output(false);
+ }
+}
+
+static void child_output(struct child_data *child, uint32_t events,
+ bool flush)
+{
+ char read_data[1024];
+ char work[1024];
+ int ret, len, cur_work, cur_read;
+
+ if (events & EPOLLIN) {
+ ret = read(child->stdout, read_data, sizeof(read_data));
+ if (ret < 0) {
+ ksft_print_msg("%s: read() failed: %s (%d)\n",
+ child->name, strerror(errno), errno);
+ return;
+ }
+ len = ret;
+
+ child->output_seen = true;
+
+ /* Pick up any partial read */
+ if (child->output) {
+ strncpy(work, child->output, sizeof(work) - 1);
+ cur_work = strnlen(work, sizeof(work));
+ free(child->output);
+ child->output = NULL;
+ } else {
+ cur_work = 0;
+ }
+
+ cur_read = 0;
+ while (cur_read < len) {
+ work[cur_work] = read_data[cur_read++];
+
+ if (work[cur_work] == '\n') {
+ work[cur_work] = '\0';
+ ksft_print_msg("%s: %s\n", child->name, work);
+ cur_work = 0;
+ } else {
+ cur_work++;
+ }
+ }
+
+ if (cur_work) {
+ work[cur_work] = '\0';
+ ret = asprintf(&child->output, "%s", work);
+ if (ret == -1)
+ ksft_exit_fail_msg("Out of memory\n");
+ }
+ }
+
+ if (events & EPOLLHUP) {
+ close(child->stdout);
+ child->stdout = -1;
+ flush = true;
+ }
+
+ if (flush && child->output) {
+ ksft_print_msg("%s: %s<EOF>\n", child->name, child->output);
+ free(child->output);
+ child->output = NULL;
+ }
+}
+
+static void child_tickle(struct child_data *child)
+{
+ if (child->output_seen && !child->exited)
+ kill(child->pid, SIGUSR2);
+}
+
+static void child_stop(struct child_data *child)
+{
+ if (!child->exited)
+ kill(child->pid, SIGTERM);
+}
+
+static void child_cleanup(struct child_data *child)
+{
+ pid_t ret;
+ int status;
+ bool fail = false;
+
+ if (!child->exited) {
+ do {
+ ret = waitpid(child->pid, &status, 0);
+ if (ret == -1 && errno == EINTR)
+ continue;
+
+ if (ret == -1) {
+ ksft_print_msg("waitpid(%d) failed: %s (%d)\n",
+ child->pid, strerror(errno),
+ errno);
+ fail = true;
+ break;
+ }
+ } while (!WIFEXITED(status));
+ child->exit_status = WEXITSTATUS(status);
+ }
+
+ if (!child->output_seen) {
+ ksft_print_msg("%s no output seen\n", child->name);
+ fail = true;
+ }
+
+ if (child->exit_status != 0) {
+ ksft_print_msg("%s exited with error code %d\n",
+ child->name, child->exit_status);
+ fail = true;
+ }
+
+ ksft_test_result(!fail, "%s\n", child->name);
+}
+
+static void handle_child_signal(int sig, siginfo_t *info, void *context)
+{
+ int i;
+ bool found = false;
+
+ for (i = 0; i < num_children; i++) {
+ if (children[i].pid == info->si_pid) {
+ children[i].exited = true;
+ children[i].exit_status = info->si_status;
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ ksft_print_msg("SIGCHILD for unknown PID %d with status %d\n",
+ info->si_pid, info->si_status);
+}
+
+static void handle_exit_signal(int sig, siginfo_t *info, void *context)
+{
+ int i;
+
+ ksft_print_msg("Got signal, exiting...\n");
+
+ terminate = true;
+
+ /*
+ * This should be redundant, the main loop should clean up
+ * after us, but for safety stop everything we can here.
+ */
+ for (i = 0; i < num_children; i++)
+ child_stop(&children[i]);
+}
+
+static void start_fpsimd(struct child_data *child, int cpu, int copy)
+{
+ int ret;
+
+ child_start(child, "./fpsimd-test");
+
+ ret = asprintf(&child->name, "FPSIMD-%d-%d", cpu, copy);
+ if (ret == -1)
+ ksft_exit_fail_msg("asprintf() failed\n");
+
+ ksft_print_msg("Started %s\n", child->name);
+}
+
+static void start_sve(struct child_data *child, int vl, int cpu)
+{
+ int ret;
+
+ ret = prctl(PR_SVE_SET_VL, vl | PR_SVE_VL_INHERIT);
+ if (ret < 0)
+ ksft_exit_fail_msg("Failed to set SVE VL %d\n", vl);
+
+ child_start(child, "./sve-test");
+
+ ret = asprintf(&child->name, "SVE-VL-%d-%d", vl, cpu);
+ if (ret == -1)
+ ksft_exit_fail_msg("asprintf() failed\n");
+
+ ksft_print_msg("Started %s\n", child->name);
+}
+
+static void start_ssve(struct child_data *child, int vl, int cpu)
+{
+ int ret;
+
+ ret = prctl(PR_SME_SET_VL, vl | PR_SME_VL_INHERIT);
+ if (ret < 0)
+ ksft_exit_fail_msg("Failed to set SME VL %d\n", ret);
+
+ child_start(child, "./ssve-test");
+
+ ret = asprintf(&child->name, "SSVE-VL-%d-%d", vl, cpu);
+ if (ret == -1)
+ ksft_exit_fail_msg("asprintf() failed\n");
+
+ ksft_print_msg("Started %s\n", child->name);
+}
+
+static void start_za(struct child_data *child, int vl, int cpu)
+{
+ int ret;
+
+ ret = prctl(PR_SME_SET_VL, vl | PR_SVE_VL_INHERIT);
+ if (ret < 0)
+ ksft_exit_fail_msg("Failed to set SME VL %d\n", ret);
+
+ child_start(child, "./za-test");
+
+ ret = asprintf(&child->name, "ZA-VL-%d-%d", vl, cpu);
+ if (ret == -1)
+ ksft_exit_fail_msg("asprintf() failed\n");
+
+ ksft_print_msg("Started %s\n", child->name);
+}
+
+static void probe_vls(int vls[], int *vl_count, int set_vl)
+{
+ unsigned int vq;
+ int vl;
+
+ *vl_count = 0;
+
+ for (vq = SVE_VQ_MAX; vq > 0; --vq) {
+ vl = prctl(set_vl, vq * 16);
+ if (vl == -1)
+ ksft_exit_fail_msg("SET_VL failed: %s (%d)\n",
+ strerror(errno), errno);
+
+ vl &= PR_SVE_VL_LEN_MASK;
+
+ vq = sve_vq_from_vl(vl);
+
+ vls[*vl_count] = vl;
+ *vl_count += 1;
+ }
+}
+
+/* Handle any pending output without blocking */
+static void drain_output(bool flush)
+{
+ struct epoll_event ev;
+ int ret = 1;
+
+ while (ret > 0) {
+ ret = epoll_wait(epoll_fd, &ev, 1, 0);
+ if (ret < 0) {
+ if (errno == EINTR)
+ continue;
+ ksft_print_msg("epoll_wait() failed: %s (%d)\n",
+ strerror(errno), errno);
+ }
+
+ if (ret == 1)
+ child_output(ev.data.ptr, ev.events, flush);
+ }
+}
+
+static const struct option options[] = {
+ { "timeout", required_argument, NULL, 't' },
+ { }
+};
+
+int main(int argc, char **argv)
+{
+ int ret;
+ int timeout = 10;
+ int cpus, tests, i, j, c;
+ int sve_vl_count, sme_vl_count, fpsimd_per_cpu;
+ int sve_vls[MAX_VLS], sme_vls[MAX_VLS];
+ struct epoll_event ev;
+ struct sigaction sa;
+
+ while ((c = getopt_long(argc, argv, "t:", options, NULL)) != -1) {
+ switch (c) {
+ case 't':
+ ret = sscanf(optarg, "%d", &timeout);
+ if (ret != 1)
+ ksft_exit_fail_msg("Failed to parse timeout %s\n",
+ optarg);
+ break;
+ default:
+ ksft_exit_fail_msg("Unknown argument\n");
+ }
+ }
+
+ cpus = num_processors();
+ tests = 0;
+
+ if (getauxval(AT_HWCAP) & HWCAP_SVE) {
+ probe_vls(sve_vls, &sve_vl_count, PR_SVE_SET_VL);
+ tests += sve_vl_count * cpus;
+ } else {
+ sve_vl_count = 0;
+ }
+
+ if (getauxval(AT_HWCAP2) & HWCAP2_SME) {
+ probe_vls(sme_vls, &sme_vl_count, PR_SME_SET_VL);
+ tests += sme_vl_count * cpus * 2;
+ } else {
+ sme_vl_count = 0;
+ }
+
+ /* Force context switching if we only have FPSIMD */
+ if (!sve_vl_count && !sme_vl_count)
+ fpsimd_per_cpu = 2;
+ else
+ fpsimd_per_cpu = 1;
+ tests += cpus * fpsimd_per_cpu;
+
+ ksft_print_header();
+ ksft_set_plan(tests);
+
+ ksft_print_msg("%d CPUs, %d SVE VLs, %d SME VLs\n",
+ cpus, sve_vl_count, sme_vl_count);
+
+ if (timeout > 0)
+ ksft_print_msg("Will run for %ds\n", timeout);
+ else
+ ksft_print_msg("Will run until terminated\n");
+
+ children = calloc(sizeof(*children), tests);
+ if (!children)
+ ksft_exit_fail_msg("Unable to allocate child data\n");
+
+ ret = epoll_create1(EPOLL_CLOEXEC);
+ if (ret < 0)
+ ksft_exit_fail_msg("epoll_create1() failed: %s (%d)\n",
+ strerror(errno), ret);
+ epoll_fd = ret;
+
+ /* Get signal handers ready before we start any children */
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_sigaction = handle_exit_signal;
+ sa.sa_flags = SA_RESTART | SA_SIGINFO;
+ sigemptyset(&sa.sa_mask);
+ ret = sigaction(SIGINT, &sa, NULL);
+ if (ret < 0)
+ ksft_print_msg("Failed to install SIGINT handler: %s (%d)\n",
+ strerror(errno), errno);
+ ret = sigaction(SIGTERM, &sa, NULL);
+ if (ret < 0)
+ ksft_print_msg("Failed to install SIGTEM handler: %s (%d)\n",
+ strerror(errno), errno);
+ sa.sa_sigaction = handle_child_signal;
+ ret = sigaction(SIGCHLD, &sa, NULL);
+ if (ret < 0)
+ ksft_print_msg("Failed to install SIGCHLD handler: %s (%d)\n",
+ strerror(errno), errno);
+
+ for (i = 0; i < cpus; i++) {
+ for (j = 0; j < fpsimd_per_cpu; j++)
+ start_fpsimd(&children[num_children++], i, j);
+
+ for (j = 0; j < sve_vl_count; j++)
+ start_sve(&children[num_children++], sve_vls[j], i);
+
+ for (j = 0; j < sme_vl_count; j++) {
+ start_ssve(&children[num_children++], sme_vls[j], i);
+ start_za(&children[num_children++], sme_vls[j], i);
+ }
+ }
+
+ for (;;) {
+ /* Did we get a signal asking us to exit? */
+ if (terminate)
+ break;
+
+ /*
+ * Timeout is counted in seconds with no output, the
+ * tests print during startup then are silent when
+ * running so this should ensure they all ran enough
+ * to install the signal handler, this is especially
+ * useful in emulation where we will both be slow and
+ * likely to have a large set of VLs.
+ */
+ ret = epoll_wait(epoll_fd, &ev, 1, 1000);
+ if (ret < 0) {
+ if (errno == EINTR)
+ continue;
+ ksft_exit_fail_msg("epoll_wait() failed: %s (%d)\n",
+ strerror(errno), errno);
+ }
+
+ /* Output? */
+ if (ret == 1) {
+ child_output(ev.data.ptr, ev.events, false);
+ continue;
+ }
+
+ /* Otherwise epoll_wait() timed out */
+
+ for (i = 0; i < num_children; i++)
+ child_tickle(&children[i]);
+
+ /* Negative timeout means run indefinitely */
+ if (timeout < 0)
+ continue;
+ if (--timeout == 0)
+ break;
+ }
+
+ ksft_print_msg("Finishing up...\n");
+
+ for (i = 0; i < tests; i++)
+ child_stop(&children[i]);
+
+ drain_output(false);
+
+ for (i = 0; i < tests; i++)
+ child_cleanup(&children[i]);
+
+ drain_output(true);
+
+ ksft_print_cnts();
+
+ return 0;
+}