linux/tools/testing/selftests/powerpc/utils.c
Michael Ellerman d89002397c selftests/powerpc: Move set_dscr() into rfi_flush.c
This version of set_dscr() was added for the RFI flush test, and is
fairly specific to it. It also clashes with the version of set_dscr()
in dscr/dscr.h. So move it into the RFI flush test where it's used.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015727.1977134-3-mpe@ellerman.id.au
2020-09-08 22:23:57 +10:00

304 lines
5.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2013-2015, Michael Ellerman, IBM Corp.
*/
#define _GNU_SOURCE /* For CPU_ZERO etc. */
#include <elf.h>
#include <errno.h>
#include <fcntl.h>
#include <link.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/sysinfo.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <unistd.h>
#include <asm/unistd.h>
#include <linux/limits.h>
#include "utils.h"
static char auxv[4096];
int read_auxv(char *buf, ssize_t buf_size)
{
ssize_t num;
int rc, fd;
fd = open("/proc/self/auxv", O_RDONLY);
if (fd == -1) {
perror("open");
return -errno;
}
num = read(fd, buf, buf_size);
if (num < 0) {
perror("read");
rc = -EIO;
goto out;
}
if (num > buf_size) {
printf("overflowed auxv buffer\n");
rc = -EOVERFLOW;
goto out;
}
rc = 0;
out:
close(fd);
return rc;
}
void *find_auxv_entry(int type, char *auxv)
{
ElfW(auxv_t) *p;
p = (ElfW(auxv_t) *)auxv;
while (p->a_type != AT_NULL) {
if (p->a_type == type)
return p;
p++;
}
return NULL;
}
void *get_auxv_entry(int type)
{
ElfW(auxv_t) *p;
if (read_auxv(auxv, sizeof(auxv)))
return NULL;
p = find_auxv_entry(type, auxv);
if (p)
return (void *)p->a_un.a_val;
return NULL;
}
int pick_online_cpu(void)
{
int ncpus, cpu = -1;
cpu_set_t *mask;
size_t size;
ncpus = get_nprocs_conf();
size = CPU_ALLOC_SIZE(ncpus);
mask = CPU_ALLOC(ncpus);
if (!mask) {
perror("malloc");
return -1;
}
CPU_ZERO_S(size, mask);
if (sched_getaffinity(0, size, mask)) {
perror("sched_getaffinity");
goto done;
}
/* We prefer a primary thread, but skip 0 */
for (cpu = 8; cpu < ncpus; cpu += 8)
if (CPU_ISSET_S(cpu, size, mask))
goto done;
/* Search for anything, but in reverse */
for (cpu = ncpus - 1; cpu >= 0; cpu--)
if (CPU_ISSET_S(cpu, size, mask))
goto done;
printf("No cpus in affinity mask?!\n");
done:
CPU_FREE(mask);
return cpu;
}
bool is_ppc64le(void)
{
struct utsname uts;
int rc;
errno = 0;
rc = uname(&uts);
if (rc) {
perror("uname");
return false;
}
return strcmp(uts.machine, "ppc64le") == 0;
}
int read_sysfs_file(char *fpath, char *result, size_t result_size)
{
char path[PATH_MAX] = "/sys/";
int rc = -1, fd;
strncat(path, fpath, PATH_MAX - strlen(path) - 1);
if ((fd = open(path, O_RDONLY)) < 0)
return rc;
rc = read(fd, result, result_size);
close(fd);
if (rc < 0)
return rc;
return 0;
}
int read_debugfs_file(char *debugfs_file, int *result)
{
int rc = -1, fd;
char path[PATH_MAX];
char value[16];
strcpy(path, "/sys/kernel/debug/");
strncat(path, debugfs_file, PATH_MAX - strlen(path) - 1);
if ((fd = open(path, O_RDONLY)) < 0)
return rc;
if ((rc = read(fd, value, sizeof(value))) < 0)
return rc;
value[15] = 0;
*result = atoi(value);
close(fd);
return 0;
}
int write_debugfs_file(char *debugfs_file, int result)
{
int rc = -1, fd;
char path[PATH_MAX];
char value[16];
strcpy(path, "/sys/kernel/debug/");
strncat(path, debugfs_file, PATH_MAX - strlen(path) - 1);
if ((fd = open(path, O_WRONLY)) < 0)
return rc;
snprintf(value, 16, "%d", result);
if ((rc = write(fd, value, strlen(value))) < 0)
return rc;
close(fd);
return 0;
}
static long perf_event_open(struct perf_event_attr *hw_event, pid_t pid,
int cpu, int group_fd, unsigned long flags)
{
return syscall(__NR_perf_event_open, hw_event, pid, cpu,
group_fd, flags);
}
static void perf_event_attr_init(struct perf_event_attr *event_attr,
unsigned int type,
unsigned long config)
{
memset(event_attr, 0, sizeof(*event_attr));
event_attr->type = type;
event_attr->size = sizeof(struct perf_event_attr);
event_attr->config = config;
event_attr->read_format = PERF_FORMAT_GROUP;
event_attr->disabled = 1;
event_attr->exclude_kernel = 1;
event_attr->exclude_hv = 1;
event_attr->exclude_guest = 1;
}
int perf_event_open_counter(unsigned int type,
unsigned long config, int group_fd)
{
int fd;
struct perf_event_attr event_attr;
perf_event_attr_init(&event_attr, type, config);
fd = perf_event_open(&event_attr, 0, -1, group_fd, 0);
if (fd < 0)
perror("perf_event_open() failed");
return fd;
}
int perf_event_enable(int fd)
{
if (ioctl(fd, PERF_EVENT_IOC_ENABLE, PERF_IOC_FLAG_GROUP) == -1) {
perror("error while enabling perf events");
return -1;
}
return 0;
}
int perf_event_disable(int fd)
{
if (ioctl(fd, PERF_EVENT_IOC_DISABLE, PERF_IOC_FLAG_GROUP) == -1) {
perror("error disabling perf events");
return -1;
}
return 0;
}
int perf_event_reset(int fd)
{
if (ioctl(fd, PERF_EVENT_IOC_RESET, PERF_IOC_FLAG_GROUP) == -1) {
perror("error resetting perf events");
return -1;
}
return 0;
}
int using_hash_mmu(bool *using_hash)
{
char line[128];
FILE *f;
int rc;
f = fopen("/proc/cpuinfo", "r");
FAIL_IF(!f);
rc = 0;
while (fgets(line, sizeof(line), f) != NULL) {
if (!strcmp(line, "MMU : Hash\n") ||
!strcmp(line, "platform : Cell\n") ||
!strcmp(line, "platform : PowerMac\n")) {
*using_hash = true;
goto out;
}
if (strcmp(line, "MMU : Radix\n") == 0) {
*using_hash = false;
goto out;
}
}
rc = -1;
out:
fclose(f);
return rc;
}