1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * POWER Data Stream Control Register (DSCR) sysfs interface test
4 *
5 * This test updates to system wide DSCR default through the sysfs interface
6 * and then verifies that all the CPU specific DSCR defaults are updated as
7 * well verified from their sysfs interfaces.
8 *
9 * Copyright 2015, Anshuman Khandual, IBM Corporation.
10 */
11#include "dscr.h"
12
13static int check_cpu_dscr_default(char *file, unsigned long val)
14{
15	unsigned long cpu_dscr;
16	int err;
17
18	err = read_ulong(file, &cpu_dscr, 16);
19	if (err)
20		return err;
21
22	if (cpu_dscr != val) {
23		printf("DSCR match failed: %ld (system) %ld (cpu)\n",
24					val, cpu_dscr);
25		return 1;
26	}
27	return 0;
28}
29
30static int check_all_cpu_dscr_defaults(unsigned long val)
31{
32	DIR *sysfs;
33	struct dirent *dp;
34	char file[LEN_MAX];
35
36	sysfs = opendir(CPU_PATH);
37	if (!sysfs) {
38		perror("opendir() failed");
39		return 1;
40	}
41
42	while ((dp = readdir(sysfs))) {
43		int len;
44
45		if (!(dp->d_type & DT_DIR))
46			continue;
47		if (!strcmp(dp->d_name, "cpuidle"))
48			continue;
49		if (!strstr(dp->d_name, "cpu"))
50			continue;
51
52		len = snprintf(file, LEN_MAX, "%s%s/dscr", CPU_PATH, dp->d_name);
53		if (len >= LEN_MAX)
54			continue;
55		if (access(file, F_OK))
56			continue;
57
58		if (check_cpu_dscr_default(file, val)) {
59			closedir(sysfs);
60			return 1;
61		}
62	}
63	closedir(sysfs);
64	return 0;
65}
66
67int dscr_sysfs(void)
68{
69	unsigned long orig_dscr_default;
70
71	SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
72
73	orig_dscr_default = get_default_dscr();
74	for (int i = 0; i < DSCR_MAX; i++) {
75		set_default_dscr(i);
76		if (check_all_cpu_dscr_defaults(i))
77			goto fail;
78	}
79	set_default_dscr(orig_dscr_default);
80	return 0;
81fail:
82	set_default_dscr(orig_dscr_default);
83	return 1;
84}
85
86int main(int argc, char *argv[])
87{
88	return test_harness(dscr_sysfs, "dscr_sysfs_test");
89}
90