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-rw-r--r--Documentation/mic/mpssd/sysfs.c102
1 files changed, 102 insertions, 0 deletions
diff --git a/Documentation/mic/mpssd/sysfs.c b/Documentation/mic/mpssd/sysfs.c
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+++ b/Documentation/mic/mpssd/sysfs.c
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+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2013 Intel 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Intel MIC User Space Tools.
+ */
+
+#include "mpssd.h"
+
+#define PAGE_SIZE 4096
+
+char *
+readsysfs(char *dir, char *entry)
+{
+ char filename[PATH_MAX];
+ char value[PAGE_SIZE];
+ char *string = NULL;
+ int fd;
+ int len;
+
+ if (dir == NULL)
+ snprintf(filename, PATH_MAX, "%s/%s", MICSYSFSDIR, entry);
+ else
+ snprintf(filename, PATH_MAX,
+ "%s/%s/%s", MICSYSFSDIR, dir, entry);
+
+ fd = open(filename, O_RDONLY);
+ if (fd < 0) {
+ mpsslog("Failed to open sysfs entry '%s': %s\n",
+ filename, strerror(errno));
+ return NULL;
+ }
+
+ len = read(fd, value, sizeof(value));
+ if (len < 0) {
+ mpsslog("Failed to read sysfs entry '%s': %s\n",
+ filename, strerror(errno));
+ goto readsys_ret;
+ }
+ if (len == 0)
+ goto readsys_ret;
+
+ value[len - 1] = '\0';
+
+ string = malloc(strlen(value) + 1);
+ if (string)
+ strcpy(string, value);
+
+readsys_ret:
+ close(fd);
+ return string;
+}
+
+int
+setsysfs(char *dir, char *entry, char *value)
+{
+ char filename[PATH_MAX];
+ char *oldvalue;
+ int fd, ret = 0;
+
+ if (dir == NULL)
+ snprintf(filename, PATH_MAX, "%s/%s", MICSYSFSDIR, entry);
+ else
+ snprintf(filename, PATH_MAX, "%s/%s/%s",
+ MICSYSFSDIR, dir, entry);
+
+ oldvalue = readsysfs(dir, entry);
+
+ fd = open(filename, O_RDWR);
+ if (fd < 0) {
+ ret = errno;
+ mpsslog("Failed to open sysfs entry '%s': %s\n",
+ filename, strerror(errno));
+ goto done;
+ }
+
+ if (!oldvalue || strcmp(value, oldvalue)) {
+ if (write(fd, value, strlen(value)) < 0) {
+ ret = errno;
+ mpsslog("Failed to write new sysfs entry '%s': %s\n",
+ filename, strerror(errno));
+ }
+ }
+ close(fd);
+done:
+ if (oldvalue)
+ free(oldvalue);
+ return ret;
+}
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