Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / mic / mpssd / sysfs.c

diff --git a/kernel/Documentation/mic/mpssd/sysfs.c b/kernel/Documentation/mic/mpssd/sysfs.c
new file mode 100644 (file)
index 0000000..8dd3269
--- /dev/null
+++ b/kernel/Documentation/mic/mpssd/sysfs.c
@@ -0,0 +1,102 @@
+/*
+ * 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;
+}