selftests/powerpc: Add test for all DSCR sysfs interfaces

TEST_PROGS := dscr_default_test dscr_explicit_test dscr_user_test	\

	      dscr_inherit_test dscr_inherit_exec_test

	      dscr_inherit_test dscr_inherit_exec_test dscr_sysfs_test

dscr_default_test: LDLIBS += -lpthread

/*

 * 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))) {

		if (!(dp->d_type & DT_DIR))

			continue;

		if (!strcmp(dp->d_name, "cpuidle"))

			continue;

		if (!strstr(dp->d_name, "cpu"))

			continue;

		sprintf(file, "%s%s/dscr", CPU_PATH, dp->d_name);

		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");

}