1 files changed, 350 insertions, 0 deletions
diff --git a/tools/power/cpupower/utils/helpers/sysfs.c b/tools/power/cpupower/utils/helpers/sysfs.c
new file mode 100644
index 000000000000..0c534e79652b
--- /dev/null
+++ b/tools/power/cpupower/utils/helpers/sysfs.c
@@ -0,0 +1,350 @@
+/*
+ *  (C) 2004-2009  Dominik Brodowski <linux@dominikbrodowski.de>
+ *  (C) 2011       Thomas Renninger <trenn@novell.com> Novell Inc.
+ *
+ *  Licensed under the terms of the GNU GPL License version 2.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "helpers/sysfs.h"
+
+unsigned int sysfs_read_file(const char *path, char *buf, size_t buflen)
+{
+	int fd;
+	size_t numread;
+
+	if ( ( fd = open(path, O_RDONLY) ) == -1 )
+		return 0;
+
+	numread = read(fd, buf, buflen - 1);
+	if ( numread < 1 )
+	{
+		close(fd);
+		return 0;
+	}
+
+	buf[numread] = '\0';
+	close(fd);
+
+	return numread;
+}
+
+static unsigned int sysfs_write_file(const char *path,
+				     const char *value, size_t len)
+{
+	int fd;
+	size_t numwrite;
+
+	if ( ( fd = open(path, O_WRONLY) ) == -1 )
+		return 0;
+
+	numwrite = write(fd, value, len);
+	if ( numwrite < 1 )
+	{
+		close(fd);
+		return 0;
+	}
+	close(fd);
+	return numwrite;
+}
+
+/* CPUidle idlestate specific /sys/devices/system/cpu/cpuX/cpuidle/ access */
+
+/*
+ * helper function to read file from /sys into given buffer
+ * fname is a relative path under "cpuX/cpuidle/stateX/" dir
+ * cstates starting with 0, C0 is not counted as cstate.
+ * This means if you want C1 info, pass 0 as idlestate param
+ */
+unsigned int sysfs_idlestate_read_file(unsigned int cpu, unsigned int idlestate,
+			     const char *fname, char *buf, size_t buflen)
+{
+	char path[SYSFS_PATH_MAX];
+	int fd;
+	size_t numread;
+
+	snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/cpuidle/state%u/%s",
+		 cpu, idlestate, fname);
+
+	if ( ( fd = open(path, O_RDONLY) ) == -1 )
+		return 0;
+
+	numread = read(fd, buf, buflen - 1);
+	if ( numread < 1 )
+	{
+		close(fd);
+		return 0;
+	}
+
+	buf[numread] = '\0';
+	close(fd);
+
+	return numread;
+}
+
+/* read access to files which contain one numeric value */
+
+enum idlestate_value {
+	IDLESTATE_USAGE,
+	IDLESTATE_POWER,
+	IDLESTATE_LATENCY,
+	IDLESTATE_TIME,
+	MAX_IDLESTATE_VALUE_FILES
+};
+
+static const char *idlestate_value_files[MAX_IDLESTATE_VALUE_FILES] = {
+	[IDLESTATE_USAGE] = "usage",
+	[IDLESTATE_POWER] = "power",
+	[IDLESTATE_LATENCY] = "latency",
+	[IDLESTATE_TIME]  = "time",
+};
+
+static unsigned long long sysfs_idlestate_get_one_value(unsigned int cpu,
+						     unsigned int idlestate,
+						     enum idlestate_value which)
+{
+	unsigned long long value;
+	unsigned int len;
+	char linebuf[MAX_LINE_LEN];
+	char *endp;
+
+	if ( which >= MAX_IDLESTATE_VALUE_FILES )
+		return 0;
+
+	if ( ( len = sysfs_idlestate_read_file(cpu, idlestate,
+					    idlestate_value_files[which],
+					    linebuf, sizeof(linebuf))) == 0 )
+	{
+		return 0;
+	}
+
+	value = strtoull(linebuf, &endp, 0);
+
+	if ( endp == linebuf || errno == ERANGE )
+		return 0;
+
+	return value;
+}
+
+/* read access to files which contain one string */
+
+enum idlestate_string {
+	IDLESTATE_DESC,
+	IDLESTATE_NAME,
+	MAX_IDLESTATE_STRING_FILES
+};
+
+static const char *idlestate_string_files[MAX_IDLESTATE_STRING_FILES] = {
+	[IDLESTATE_DESC] = "desc",
+	[IDLESTATE_NAME] = "name",
+};
+
+
+static char * sysfs_idlestate_get_one_string(unsigned int cpu,
+					  unsigned int idlestate,
+					  enum idlestate_string which)
+{
+	char linebuf[MAX_LINE_LEN];
+	char *result;
+	unsigned int len;
+
+	if (which >= MAX_IDLESTATE_STRING_FILES)
+		return NULL;
+
+	if ( ( len = sysfs_idlestate_read_file(cpu, idlestate,
+					    idlestate_string_files[which],
+					    linebuf, sizeof(linebuf))) == 0 )
+		return NULL;
+
+	if ( ( result = strdup(linebuf) ) == NULL )
+		return NULL;
+
+	if (result[strlen(result) - 1] == '\n')
+		result[strlen(result) - 1] = '\0';
+
+	return result;
+}
+
+unsigned long sysfs_get_idlestate_latency(unsigned int cpu, unsigned int idlestate)
+{
+	return sysfs_idlestate_get_one_value(cpu, idlestate, IDLESTATE_LATENCY);
+}
+
+unsigned long sysfs_get_idlestate_usage(unsigned int cpu, unsigned int idlestate)
+{
+	return sysfs_idlestate_get_one_value(cpu, idlestate, IDLESTATE_USAGE);
+}
+
+unsigned long long sysfs_get_idlestate_time(unsigned int cpu, unsigned int idlestate)
+{
+	return sysfs_idlestate_get_one_value(cpu, idlestate, IDLESTATE_TIME);
+}
+
+char * sysfs_get_idlestate_name(unsigned int cpu, unsigned int idlestate)
+{
+	return sysfs_idlestate_get_one_string(cpu, idlestate, IDLESTATE_NAME);
+}
+
+char * sysfs_get_idlestate_desc(unsigned int cpu, unsigned int idlestate)
+{
+	return sysfs_idlestate_get_one_string(cpu, idlestate, IDLESTATE_DESC);
+}
+
+/*
+ * Returns number of supported C-states of CPU core cpu
+ * Negativ in error case
+ * Zero if cpuidle does not export any C-states
+ */
+int sysfs_get_idlestate_count(unsigned int cpu)
+{
+	char file[SYSFS_PATH_MAX];
+	struct stat statbuf;
+	int idlestates = 1;
+
+
+	snprintf(file, SYSFS_PATH_MAX, PATH_TO_CPU "cpuidle");
+	if ( stat(file, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode))
+		return -ENODEV;
+
+	snprintf(file, SYSFS_PATH_MAX, PATH_TO_CPU "cpu%u/cpuidle/state0", cpu);
+	if ( stat(file, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode))
+		return 0;
+
+	while(stat(file, &statbuf) == 0 && S_ISDIR(statbuf.st_mode)) {
+		snprintf(file, SYSFS_PATH_MAX, PATH_TO_CPU
+			 "cpu%u/cpuidle/state%d", cpu, idlestates);
+		idlestates++;
+	}
+	idlestates--;
+	return idlestates;
+}
+
+/* CPUidle general /sys/devices/system/cpu/cpuidle/ sysfs access ********/
+
+/*
+ * helper function to read file from /sys into given buffer
+ * fname is a relative path under "cpu/cpuidle/" dir
+ */
+static unsigned int sysfs_cpuidle_read_file(const char *fname, char *buf,
+					    size_t buflen)
+{
+	char path[SYSFS_PATH_MAX];
+
+	snprintf(path, sizeof(path), PATH_TO_CPU "cpuidle/%s", fname);
+
+	return sysfs_read_file(path, buf, buflen);
+}
+
+
+
+/* read access to files which contain one string */
+
+enum cpuidle_string {
+	CPUIDLE_GOVERNOR,
+	CPUIDLE_GOVERNOR_RO,
+	CPUIDLE_DRIVER,
+	MAX_CPUIDLE_STRING_FILES
+};
+
+static const char *cpuidle_string_files[MAX_CPUIDLE_STRING_FILES] = {
+	[CPUIDLE_GOVERNOR]	= "current_governor",
+	[CPUIDLE_GOVERNOR_RO]	= "current_governor_ro",
+	[CPUIDLE_DRIVER]	= "current_driver",
+};
+
+
+static char * sysfs_cpuidle_get_one_string(enum cpuidle_string which)
+{
+	char linebuf[MAX_LINE_LEN];
+	char *result;
+	unsigned int len;
+
+	if (which >= MAX_CPUIDLE_STRING_FILES)
+		return NULL;
+
+	if ( ( len = sysfs_cpuidle_read_file(cpuidle_string_files[which],
+					    linebuf, sizeof(linebuf))) == 0 )
+		return NULL;
+
+	if ( ( result = strdup(linebuf) ) == NULL )
+		return NULL;
+
+	if (result[strlen(result) - 1] == '\n')
+		result[strlen(result) - 1] = '\0';
+
+	return result;
+}
+
+char * sysfs_get_cpuidle_governor(void)
+{
+	char *tmp = sysfs_cpuidle_get_one_string(CPUIDLE_GOVERNOR_RO);
+	if (!tmp)
+		return sysfs_cpuidle_get_one_string(CPUIDLE_GOVERNOR);
+	else
+		return tmp;
+}
+
+char * sysfs_get_cpuidle_driver(void)
+{
+	return sysfs_cpuidle_get_one_string(CPUIDLE_DRIVER);
+}
+/* CPUidle idlestate specific /sys/devices/system/cpu/cpuX/cpuidle/ access */
+
+/*
+ * Get sched_mc or sched_smt settings
+ * Pass "mc" or "smt" as argument
+ *
+ * Returns negative value on failure
+ */
+int sysfs_get_sched(const char* smt_mc)
+{
+ 	unsigned long value;
+	char linebuf[MAX_LINE_LEN];
+	char *endp;
+	char path[SYSFS_PATH_MAX];
+
+	if (strcmp("mc", smt_mc) && strcmp("smt", smt_mc))
+		return -EINVAL;
+
+	snprintf(path, sizeof(path), PATH_TO_CPU "sched_%s_power_savings", smt_mc);
+	if (sysfs_read_file(path, linebuf, MAX_LINE_LEN) == 0 )
+		return -1;
+	value = strtoul(linebuf, &endp, 0);
+	if ( endp == linebuf || errno == ERANGE )
+		return -1;
+	return value;
+}
+
+/*
+ * Get sched_mc or sched_smt settings
+ * Pass "mc" or "smt" as argument
+ *
+ * Returns negative value on failure
+ */
+int sysfs_set_sched(const char* smt_mc, int val)
+{
+	char linebuf[MAX_LINE_LEN];
+	char path[SYSFS_PATH_MAX];
+	struct stat statbuf;
+
+	if (strcmp("mc", smt_mc) && strcmp("smt", smt_mc))
+		return -EINVAL;
+
+	snprintf(path, sizeof(path), PATH_TO_CPU "sched_%s_power_savings", smt_mc);
+	sprintf(linebuf, "%d", val);
+
+	if ( stat(path, &statbuf) != 0 )
+		return -ENODEV;
+
+	if (sysfs_write_file(path, linebuf, MAX_LINE_LEN) == 0 )
+		return -1;
+	return 0;
+}