1 // SPDX-License-Identifier: GPL-2.0-only
3 * Intel MIC Platform Software Stack (MPSS)
5 * Copyright(c) 2013 Intel Corporation.
7 * Intel MIC User Space Tools.
12 #define PAGE_SIZE 4096
15 readsysfs(char *dir, char *entry)
17 char filename[PATH_MAX];
18 char value[PAGE_SIZE];
24 snprintf(filename, PATH_MAX, "%s/%s", MICSYSFSDIR, entry);
26 snprintf(filename, PATH_MAX,
27 "%s/%s/%s", MICSYSFSDIR, dir, entry);
29 fd = open(filename, O_RDONLY);
31 mpsslog("Failed to open sysfs entry '%s': %s\n",
32 filename, strerror(errno));
36 len = read(fd, value, sizeof(value));
38 mpsslog("Failed to read sysfs entry '%s': %s\n",
39 filename, strerror(errno));
45 value[len - 1] = '\0';
47 string = malloc(strlen(value) + 1);
49 strcpy(string, value);
57 setsysfs(char *dir, char *entry, char *value)
59 char filename[PATH_MAX];
64 snprintf(filename, PATH_MAX, "%s/%s", MICSYSFSDIR, entry);
66 snprintf(filename, PATH_MAX, "%s/%s/%s",
67 MICSYSFSDIR, dir, entry);
69 oldvalue = readsysfs(dir, entry);
71 fd = open(filename, O_RDWR);
74 mpsslog("Failed to open sysfs entry '%s': %s\n",
75 filename, strerror(errno));
79 if (!oldvalue || strcmp(value, oldvalue)) {
80 if (write(fd, value, strlen(value)) < 0) {
82 mpsslog("Failed to write new sysfs entry '%s': %s\n",
83 filename, strerror(errno));