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
check_cpu_dscr_default(char * file,unsigned long val)13 static int check_cpu_dscr_default(char *file, unsigned long val)
14 {
15 char buf[10];
16 int fd, rc;
17
18 fd = open(file, O_RDWR);
19 if (fd == -1) {
20 perror("open() failed");
21 return 1;
22 }
23
24 rc = read(fd, buf, sizeof(buf));
25 if (rc == -1) {
26 perror("read() failed");
27 close(fd);
28 return 1;
29 }
30 close(fd);
31
32 buf[rc] = '\0';
33 if (strtol(buf, NULL, 16) != val) {
34 printf("DSCR match failed: %ld (system) %ld (cpu)\n",
35 val, strtol(buf, NULL, 16));
36 return 1;
37 }
38 return 0;
39 }
40
check_all_cpu_dscr_defaults(unsigned long val)41 static int check_all_cpu_dscr_defaults(unsigned long val)
42 {
43 DIR *sysfs;
44 struct dirent *dp;
45 char file[LEN_MAX];
46
47 sysfs = opendir(CPU_PATH);
48 if (!sysfs) {
49 perror("opendir() failed");
50 return 1;
51 }
52
53 while ((dp = readdir(sysfs))) {
54 int len;
55
56 if (!(dp->d_type & DT_DIR))
57 continue;
58 if (!strcmp(dp->d_name, "cpuidle"))
59 continue;
60 if (!strstr(dp->d_name, "cpu"))
61 continue;
62
63 len = snprintf(file, LEN_MAX, "%s%s/dscr", CPU_PATH, dp->d_name);
64 if (len >= LEN_MAX)
65 continue;
66 if (access(file, F_OK))
67 continue;
68
69 if (check_cpu_dscr_default(file, val)) {
70 closedir(sysfs);
71 return 1;
72 }
73 }
74 closedir(sysfs);
75 return 0;
76 }
77
dscr_sysfs(void)78 int dscr_sysfs(void)
79 {
80 unsigned long orig_dscr_default;
81 int i, j;
82
83 SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
84
85 orig_dscr_default = get_default_dscr();
86 for (i = 0; i < COUNT; i++) {
87 for (j = 0; j < DSCR_MAX; j++) {
88 set_default_dscr(j);
89 if (check_all_cpu_dscr_defaults(j))
90 goto fail;
91 }
92 }
93 set_default_dscr(orig_dscr_default);
94 return 0;
95 fail:
96 set_default_dscr(orig_dscr_default);
97 return 1;
98 }
99
main(int argc,char * argv[])100 int main(int argc, char *argv[])
101 {
102 return test_harness(dscr_sysfs, "dscr_sysfs_test");
103 }
104