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Based on kernel version 3.16. Page generated on 2014-08-06 21:40 EST.

1	/*
2	 * Intel MIC Platform Software Stack (MPSS)
3	 *
4	 * Copyright(c) 2013 Intel Corporation.
5	 *
6	 * This program is free software; you can redistribute it and/or modify
7	 * it under the terms of the GNU General Public License, version 2, as
8	 * published by the Free Software Foundation.
9	 *
10	 * This program is distributed in the hope that it will be useful, but
11	 * WITHOUT ANY WARRANTY; without even the implied warranty of
12	 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13	 * General Public License for more details.
14	 *
15	 * The full GNU General Public License is included in this distribution in
16	 * the file called "COPYING".
17	 *
18	 * Intel MIC User Space Tools.
19	 */
20	
21	#include "mpssd.h"
22	
23	#define PAGE_SIZE 4096
24	
25	char *
26	readsysfs(char *dir, char *entry)
27	{
28		char filename[PATH_MAX];
29		char value[PAGE_SIZE];
30		char *string = NULL;
31		int fd;
32		int len;
33	
34		if (dir == NULL)
35			snprintf(filename, PATH_MAX, "%s/%s", MICSYSFSDIR, entry);
36		else
37			snprintf(filename, PATH_MAX,
38				 "%s/%s/%s", MICSYSFSDIR, dir, entry);
39	
40		fd = open(filename, O_RDONLY);
41		if (fd < 0) {
42			mpsslog("Failed to open sysfs entry '%s': %s\n",
43				filename, strerror(errno));
44			return NULL;
45		}
46	
47		len = read(fd, value, sizeof(value));
48		if (len < 0) {
49			mpsslog("Failed to read sysfs entry '%s': %s\n",
50				filename, strerror(errno));
51			goto readsys_ret;
52		}
53		if (len == 0)
54			goto readsys_ret;
55	
56		value[len - 1] = '\0';
57	
58		string = malloc(strlen(value) + 1);
59		if (string)
60			strcpy(string, value);
61	
62	readsys_ret:
63		close(fd);
64		return string;
65	}
66	
67	int
68	setsysfs(char *dir, char *entry, char *value)
69	{
70		char filename[PATH_MAX];
71		char *oldvalue;
72		int fd, ret = 0;
73	
74		if (dir == NULL)
75			snprintf(filename, PATH_MAX, "%s/%s", MICSYSFSDIR, entry);
76		else
77			snprintf(filename, PATH_MAX, "%s/%s/%s",
78				 MICSYSFSDIR, dir, entry);
79	
80		oldvalue = readsysfs(dir, entry);
81	
82		fd = open(filename, O_RDWR);
83		if (fd < 0) {
84			ret = errno;
85			mpsslog("Failed to open sysfs entry '%s': %s\n",
86				filename, strerror(errno));
87			goto done;
88		}
89	
90		if (!oldvalue || strcmp(value, oldvalue)) {
91			if (write(fd, value, strlen(value)) < 0) {
92				ret = errno;
93				mpsslog("Failed to write new sysfs entry '%s': %s\n",
94					filename, strerror(errno));
95			}
96		}
97		close(fd);
98	done:
99		if (oldvalue)
100			free(oldvalue);
101		return ret;
102	}
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