cpupower: Add cpuidle parts into library

This more or less is a renaming and moving of functions and should not
introduce any functional change.

cpupower was built from cpufrequtils (which had a C library providing easy
access to cpu frequency platform info). In the meantime it got enhanced
by quite some neat cpuidle userspace tools.

Now the cpu idle functions have been separated and added to the cpupower.so
library.
So beside an already existing public header file:
cpufreq.h
cpupower now also exports these cpu idle functions in:
cpuidle.h

Here again pasted for better review of the interfaces:

======================================
int cpuidle_is_state_disabled(unsigned int cpu,
                                       unsigned int idlestate);
int cpuidle_state_disable(unsigned int cpu, unsigned int idlestate,
                                   unsigned int disable);
unsigned long cpuidle_state_latency(unsigned int cpu,
                                                unsigned int idlestate);
unsigned long cpuidle_state_usage(unsigned int cpu,
                                        unsigned int idlestate);
unsigned long long cpuidle_state_time(unsigned int cpu,
                                                unsigned int idlestate);
char *cpuidle_state_name(unsigned int cpu,
                                unsigned int idlestate);
char *cpuidle_state_desc(unsigned int cpu,
                                unsigned int idlestate);
unsigned int cpuidle_state_count(unsigned int cpu);

char *cpuidle_get_governor(void);
char *cpuidle_get_driver(void);

======================================

Signed-off-by: Thomas Renninger <trenn@suse.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 192 insertions, 0 deletions

diff --git a/tools/power/cpupower/lib/cpupower.c b/tools/power/cpupower/lib/cpupower.c
new file mode 100644
index 000000000000..9c395ec924de
--- /dev/null
+++ b/tools/power/cpupower/lib/cpupower.c
@@ -0,0 +1,192 @@
+/*
+ *  (C) 2004-2009  Dominik Brodowski <linux@dominikbrodowski.de>
+ *
+ *  Licensed under the terms of the GNU GPL License version 2.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+
+#include "cpupower.h"
+#include "cpupower_intern.h"
+
+unsigned int sysfs_read_file(const char *path, char *buf, size_t buflen)
+{
+	int fd;
+	ssize_t numread;
+
+	fd = open(path, O_RDONLY);
+	if (fd == -1)
+		return 0;
+
+	numread = read(fd, buf, buflen - 1);
+	if (numread < 1) {
+		close(fd);
+		return 0;
+	}
+
+	buf[numread] = '\0';
+	close(fd);
+
+	return (unsigned int) numread;
+}
+
+/*
+ * Detect whether a CPU is online
+ *
+ * Returns:
+ *     1 -> if CPU is online
+ *     0 -> if CPU is offline
+ *     negative errno values in error case
+ */
+int cpupower_is_cpu_online(unsigned int cpu)
+{
+	char path[SYSFS_PATH_MAX];
+	int fd;
+	ssize_t numread;
+	unsigned long long value;
+	char linebuf[MAX_LINE_LEN];
+	char *endp;
+	struct stat statbuf;
+
+	snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u", cpu);
+
+	if (stat(path, &statbuf) != 0)
+		return 0;
+
+	/*
+	 * kernel without CONFIG_HOTPLUG_CPU
+	 * -> cpuX directory exists, but not cpuX/online file
+	 */
+	snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/online", cpu);
+	if (stat(path, &statbuf) != 0)
+		return 1;
+
+	fd = open(path, O_RDONLY);
+	if (fd == -1)
+		return -errno;
+
+	numread = read(fd, linebuf, MAX_LINE_LEN - 1);
+	if (numread < 1) {
+		close(fd);
+		return -EIO;
+	}
+	linebuf[numread] = '\0';
+	close(fd);
+
+	value = strtoull(linebuf, &endp, 0);
+	if (value > 1)
+		return -EINVAL;
+
+	return value;
+}
+
+/* returns -1 on failure, 0 on success */
+static int sysfs_topology_read_file(unsigned int cpu, const char *fname, int *result)
+{
+	char linebuf[MAX_LINE_LEN];
+	char *endp;
+	char path[SYSFS_PATH_MAX];
+
+	snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/topology/%s",
+			 cpu, fname);
+	if (sysfs_read_file(path, linebuf, MAX_LINE_LEN) == 0)
+		return -1;
+	*result = strtol(linebuf, &endp, 0);
+	if (endp == linebuf || errno == ERANGE)
+		return -1;
+	return 0;
+}
+
+static int __compare(const void *t1, const void *t2)
+{
+	struct cpuid_core_info *top1 = (struct cpuid_core_info *)t1;
+	struct cpuid_core_info *top2 = (struct cpuid_core_info *)t2;
+	if (top1->pkg < top2->pkg)
+		return -1;
+	else if (top1->pkg > top2->pkg)
+		return 1;
+	else if (top1->core < top2->core)
+		return -1;
+	else if (top1->core > top2->core)
+		return 1;
+	else if (top1->cpu < top2->cpu)
+		return -1;
+	else if (top1->cpu > top2->cpu)
+		return 1;
+	else
+		return 0;
+}
+
+/*
+ * Returns amount of cpus, negative on error, cpu_top must be
+ * passed to cpu_topology_release to free resources
+ *
+ * Array is sorted after ->pkg, ->core, then ->cpu
+ */
+int get_cpu_topology(struct cpupower_topology *cpu_top)
+{
+	int cpu, last_pkg, cpus = sysconf(_SC_NPROCESSORS_CONF);
+
+	cpu_top->core_info = malloc(sizeof(struct cpuid_core_info) * cpus);
+	if (cpu_top->core_info == NULL)
+		return -ENOMEM;
+	cpu_top->pkgs = cpu_top->cores = 0;
+	for (cpu = 0; cpu < cpus; cpu++) {
+		cpu_top->core_info[cpu].cpu = cpu;
+		cpu_top->core_info[cpu].is_online = cpupower_is_cpu_online(cpu);
+		if(sysfs_topology_read_file(
+			cpu,
+			"physical_package_id",
+			&(cpu_top->core_info[cpu].pkg)) < 0) {
+			cpu_top->core_info[cpu].pkg = -1;
+			cpu_top->core_info[cpu].core = -1;
+			continue;
+		}
+		if(sysfs_topology_read_file(
+			cpu,
+			"core_id",
+			&(cpu_top->core_info[cpu].core)) < 0) {
+			cpu_top->core_info[cpu].pkg = -1;
+			cpu_top->core_info[cpu].core = -1;
+			continue;
+		}
+	}
+
+	qsort(cpu_top->core_info, cpus, sizeof(struct cpuid_core_info),
+	      __compare);
+
+	/* Count the number of distinct pkgs values. This works
+	   because the primary sort of the core_info struct was just
+	   done by pkg value. */
+	last_pkg = cpu_top->core_info[0].pkg;
+	for(cpu = 1; cpu < cpus; cpu++) {
+		if (cpu_top->core_info[cpu].pkg != last_pkg &&
+				cpu_top->core_info[cpu].pkg != -1) {
+
+			last_pkg = cpu_top->core_info[cpu].pkg;
+			cpu_top->pkgs++;
+		}
+	}
+	if (!(cpu_top->core_info[0].pkg == -1))
+		cpu_top->pkgs++;
+
+	/* Intel's cores count is not consecutively numbered, there may
+	 * be a core_id of 3, but none of 2. Assume there always is 0
+	 * Get amount of cores by counting duplicates in a package
+	for (cpu = 0; cpu_top->core_info[cpu].pkg = 0 && cpu < cpus; cpu++) {
+		if (cpu_top->core_info[cpu].core == 0)
+	cpu_top->cores++;
+	*/
+	return cpus;
+}
+
+void cpu_topology_release(struct cpupower_topology cpu_top)
+{
+	free(cpu_top.core_info);
+}