ubuntu-linux-kernel/tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c

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2024-04-01 15:06:58 +00:00
/*
* POWER Data Stream Control Register (DSCR) sysfs interface test
*
* This test updates to system wide DSCR default through the sysfs interface
* and then verifies that all the CPU specific DSCR defaults are updated as
* well verified from their sysfs interfaces.
*
* Copyright 2015, Anshuman Khandual, IBM Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*/
#include "dscr.h"
static int check_cpu_dscr_default(char *file, unsigned long val)
{
char buf[10];
int fd, rc;
fd = open(file, O_RDWR);
if (fd == -1) {
perror("open() failed");
return 1;
}
rc = read(fd, buf, sizeof(buf));
if (rc == -1) {
perror("read() failed");
return 1;
}
close(fd);
buf[rc] = '\0';
if (strtol(buf, NULL, 16) != val) {
printf("DSCR match failed: %ld (system) %ld (cpu)\n",
val, strtol(buf, NULL, 16));
return 1;
}
return 0;
}
static int check_all_cpu_dscr_defaults(unsigned long val)
{
DIR *sysfs;
struct dirent *dp;
char file[LEN_MAX];
sysfs = opendir(CPU_PATH);
if (!sysfs) {
perror("opendir() failed");
return 1;
}
while ((dp = readdir(sysfs))) {
int len;
if (!(dp->d_type & DT_DIR))
continue;
if (!strcmp(dp->d_name, "cpuidle"))
continue;
if (!strstr(dp->d_name, "cpu"))
continue;
len = snprintf(file, LEN_MAX, "%s%s/dscr", CPU_PATH, dp->d_name);
if (len >= LEN_MAX)
continue;
if (access(file, F_OK))
continue;
if (check_cpu_dscr_default(file, val))
return 1;
}
closedir(sysfs);
return 0;
}
int dscr_sysfs(void)
{
unsigned long orig_dscr_default;
int i, j;
orig_dscr_default = get_default_dscr();
for (i = 0; i < COUNT; i++) {
for (j = 0; j < DSCR_MAX; j++) {
set_default_dscr(j);
if (check_all_cpu_dscr_defaults(j))
goto fail;
}
}
set_default_dscr(orig_dscr_default);
return 0;
fail:
set_default_dscr(orig_dscr_default);
return 1;
}
int main(int argc, char *argv[])
{
return test_harness(dscr_sysfs, "dscr_sysfs_test");
}