Initial s390-tools-2.0.0 import

This commit is based on the s390-tools-1.39.0 version.

Changes on top of s390-tools-1.39.0:

 - Add MIT license to all source files
 - Add LICENSE file
 - Transform REAMDE to README.md (markdown)
 - Add AUTHORS.md file
 - Add CONTRIBUTING.md file
 - Move changelog from README to CHANGELOG.md file

Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>

cpuplugd/info.c

@@ -0,0 +1,157 @@
+/*
+ * cpuplugd - Linux for System z Hotplug Daemon
+ *
+ * /proc info functions
+ *
+ * Copyright IBM Corp. 2007, 2017
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "cpuplugd.h"
+
+/*
+ * Return current load average and runnable processes based on /proc/loadavg
+ *
+ * Example: 0.20 0.18 0.12 1/80 11206
+ *
+ * The first three columns measure CPU utilization of the last 1, 5,
+ * and 15 minute periods.
+ * The fourth column shows the number of currently running processes
+ * and the total number of processes.
+ * The last column displays the last process ID used.
+ */
+void get_loadavg_runnable(double *loadavg, double *runnable)
+{
+	FILE *filp;
+	double dummy;
+	int rc;
+
+	filp = fopen("/proc/loadavg", "r");
+	if (!filp)
+		cpuplugd_exit("cannot open kernel loadaverage "
+			      "statistics: %s\n", strerror(errno));
+	rc = fscanf(filp, "%lf %lf %lf %lf/", loadavg, &dummy, &dummy,
+		    runnable);
+	if (rc != 4)
+		cpuplugd_exit("cannot parse kernel loadaverage "
+			      "statistics: %s\n", strerror(errno));
+	fclose(filp);
+	return;
+}
+
+void proc_cpu_read(char *procinfo)
+{
+	FILE *filp;
+	unsigned int rc, onumcpus;
+	unsigned long user, nice, system, idle, iowait, irq, softirq, steal,
+		      guest, guest_nice, total_ticks;
+	double loadavg, runnable;
+
+	guest = guest_nice = 0;		/* set to 0 if not present in kernel */
+	filp = fopen("/proc/stat", "r");
+	if (!filp)
+		cpuplugd_exit("/proc/stat open failed: %s\n", strerror(errno));
+	rc = fscanf(filp, "cpu %ld %ld %ld %ld %ld %ld %ld %ld %ld %ld", &user,
+		    &nice, &system, &idle, &iowait, &irq, &softirq, &steal,
+		    &guest, &guest_nice);
+
+	get_loadavg_runnable(&loadavg, &runnable);
+	onumcpus = get_num_online_cpus();
+	total_ticks = user + nice + system + idle + iowait + irq + softirq +
+		      steal + guest + guest_nice;
+
+	rc = snprintf(procinfo, cpustat_size, "onumcpus %d\nloadavg %f\n"
+		      "runnable_proc %f\nuser %ld\nnice %ld\nsystem %ld\n"
+		      "idle %ld\niowait %ld\nirq %ld\nsoftirq %ld\nsteal %ld\n"
+		      "guest %ld\nguest_nice %ld\ntotal_ticks %ld\n",
+		      onumcpus, loadavg, runnable, user, nice, system, idle,
+		      iowait, irq, softirq, steal, guest, guest_nice,
+		      total_ticks);
+	if (rc >= cpustat_size)
+		cpuplugd_exit("cpustat buffer too small: need %d, have %ld "
+			      "(bytes)\n", rc, cpustat_size);
+	fclose(filp);
+	return;
+}
+
+void proc_read(char *procinfo, char *path, unsigned long size)
+{
+	size_t bytes_read;
+	FILE *filp;
+
+	filp = fopen(path, "r");
+	if (!filp)
+		cpuplugd_exit("%s open failed: %s\n", path, strerror(errno));
+
+	bytes_read = fread(procinfo, 1, size, filp);
+	if (bytes_read == 0)
+		cpuplugd_exit("%s read failed\n", path);
+	if (bytes_read == size)
+		cpuplugd_exit("procinfo buffer too small for %s\n", path);
+
+	procinfo[bytes_read] = '\0';
+	fclose(filp);
+	return;
+}
+
+unsigned long proc_read_size(char *path)
+{
+	FILE *filp;
+	char buf[PROCINFO_LINE];
+	char *linep, *linep_offset;
+	unsigned long size;
+
+	filp = fopen(path, "r");
+	if (!filp)
+		cpuplugd_exit("%s open failed: %s\n", path, strerror(errno));
+
+	size = 0;
+	while ((linep = fgets(buf, sizeof(buf), filp))) {
+		if (!(linep_offset = strchr(linep, '\n')))
+			cpuplugd_exit("buf too small for line\n");
+		size = size + linep_offset - linep + 1;
+	}
+	fclose(filp);
+	return size;
+}
+
+double get_proc_value(char *procinfo, char *name, char separator)
+{
+	char buf[PROCINFO_LINE];
+	char *proc_offset;
+	unsigned long proc_length, name_length;
+	double value;
+	int found;
+
+	value = -1;
+	found = 0;
+	name_length = strlen(name);
+	while ((proc_offset = strchr(procinfo, separator))) {
+		proc_length = proc_offset - procinfo;
+		/*
+		 * proc_read_size() made sure that proc_length < PROCINFO_LINE
+		 */
+		memcpy(buf, procinfo, proc_length);
+		buf[proc_length] = '\0';
+		procinfo = proc_offset + 1;
+		if (strncmp(buf, name, MAX(proc_length, name_length)) == 0) {
+			errno = 0;
+			value = strtod(procinfo, NULL);
+			if (errno)
+				cpuplugd_exit("strtod failed\n");
+			found = 1;
+			break;
+		}
+		proc_offset = strchr(procinfo, '\n');
+		procinfo = proc_offset + 1;
+	}
+	if (!found)
+		cpuplugd_exit("Symbol %s not found, check your config file\n",
+			      name);
+	return value;
+}