tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c - arm/linux - Git at Google

 /*
  * x86_energy_perf_policy -- set the energy versus performance
  * policy preference bias on recent X86 processors.
  */
 /*
  * Copyright (c) 2010, Intel Corporation.
  * Len Brown <len.brown@intel.com>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * This program is distributed in the hope 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.
  *
  * You should have received a copy of the GNU General Public License along with
  * this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  */

 #include <stdio.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/resource.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <sys/time.h>
 #include <stdlib.h>
 #include <string.h>

 unsigned int verbose;		/* set with -v */
 unsigned int read_only;		/* set with -r */
 char *progname;
 unsigned long long new_bias;
 int cpu = -1;

 /*
  * Usage:
  *
  * -c cpu: limit action to a single CPU (default is all CPUs)
  * -v: verbose output (can invoke more than once)
  * -r: read-only, don't change any settings
  *
  *  performance
  *	Performance is paramount.
  *	Unwilling to sacrifice any performance
  *	for the sake of energy saving. (hardware default)
  *
  *  normal
  *	Can tolerate minor performance compromise
  *	for potentially significant energy savings.
  *	(reasonable default for most desktops and servers)
  *
  *  powersave
  *	Can tolerate significant performance hit
  *	to maximize energy savings.
  *
  * n
  *	a numerical value to write to the underlying MSR.
  */
 void usage(void)
 {
 	printf("%s: [-c cpu] [-v] "
 		"(-r | 'performance' | 'normal' | 'powersave' | n)\n",
 		progname);
 	exit(1);
 }

 #define MSR_IA32_ENERGY_PERF_BIAS	0x000001b0

 #define	BIAS_PERFORMANCE		0
 #define BIAS_BALANCE			6
 #define	BIAS_POWERSAVE			15

 void cmdline(int argc, char **argv)
 {
 	int opt;

 	progname = argv[0];

 	while ((opt = getopt(argc, argv, "+rvc:")) != -1) {
 		switch (opt) {
 		case 'c':
 			cpu = atoi(optarg);
 			break;
 		case 'r':
 			read_only = 1;
 			break;
 		case 'v':
 			verbose++;
 			break;
 		default:
 			usage();
 		}
 	}
 	/* if -r, then should be no additional optind */
 	if (read_only && (argc > optind))
 		usage();

 	/*
 	 * if no -r , then must be one additional optind
 	 */
 	if (!read_only) {

 		if (argc != optind + 1) {
 			printf("must supply -r or policy param\n");
 			usage();
 			}

 		if (!strcmp("performance", argv[optind])) {
 			new_bias = BIAS_PERFORMANCE;
 		} else if (!strcmp("normal", argv[optind])) {
 			new_bias = BIAS_BALANCE;
 		} else if (!strcmp("powersave", argv[optind])) {
 			new_bias = BIAS_POWERSAVE;
 		} else {
 			char *endptr;

 			new_bias = strtoull(argv[optind], &endptr, 0);
 			if (endptr == argv[optind] ||
 				new_bias > BIAS_POWERSAVE) {
 					fprintf(stderr, "invalid value: %s\n",
 						argv[optind]);
 				usage();
 			}
 		}
 	}
 }

 /*
  * validate_cpuid()
  * returns on success, quietly exits on failure (make verbose with -v)
  */
 void validate_cpuid(void)
 {
 	unsigned int eax, ebx, ecx, edx, max_level;
 	unsigned int fms, family, model, stepping;

 	eax = ebx = ecx = edx = 0;

 	asm("cpuid" : "=a" (max_level), "=b" (ebx), "=c" (ecx),
 		"=d" (edx) : "a" (0));

 	if (ebx != 0x756e6547 || edx != 0x49656e69 || ecx != 0x6c65746e) {
 		if (verbose)
 			fprintf(stderr, "%.4s%.4s%.4s != GenuineIntel",
 				(char *)&ebx, (char *)&edx, (char *)&ecx);
 		exit(1);
 	}

 	asm("cpuid" : "=a" (fms), "=c" (ecx), "=d" (edx) : "a" (1) : "ebx");
 	family = (fms >> 8) & 0xf;
 	model = (fms >> 4) & 0xf;
 	stepping = fms & 0xf;
 	if (family == 6 || family == 0xf)
 		model += ((fms >> 16) & 0xf) << 4;

 	if (verbose > 1)
 		printf("CPUID %d levels family:model:stepping "
 			"0x%x:%x:%x (%d:%d:%d)\n", max_level,
 			family, model, stepping, family, model, stepping);

 	if (!(edx & (1 << 5))) {
 		if (verbose)
 			printf("CPUID: no MSR\n");
 		exit(1);
 	}

 	/*
 	 * Support for MSR_IA32_ENERGY_PERF_BIAS
 	 * is indicated by CPUID.06H.ECX.bit3
 	 */
 	asm("cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (6));
 	if (verbose)
 		printf("CPUID.06H.ECX: 0x%x\n", ecx);
 	if (!(ecx & (1 << 3))) {
 		if (verbose)
 			printf("CPUID: No MSR_IA32_ENERGY_PERF_BIAS\n");
 		exit(1);
 	}
 	return;	/* success */
 }

 unsigned long long get_msr(int cpu, int offset)
 {
 	unsigned long long msr;
 	char msr_path[32];
 	int retval;
 	int fd;

 	sprintf(msr_path, "/dev/cpu/%d/msr", cpu);
 	fd = open(msr_path, O_RDONLY);
 	if (fd < 0) {
 		printf("Try \"# modprobe msr\"\n");
 		perror(msr_path);
 		exit(1);
 	}

 	retval = pread(fd, &msr, sizeof msr, offset);

 	if (retval != sizeof msr) {
 		printf("pread cpu%d 0x%x = %d\n", cpu, offset, retval);
 		exit(-2);
 	}
 	close(fd);
 	return msr;
 }

 unsigned long long  put_msr(int cpu, unsigned long long new_msr, int offset)
 {
 	unsigned long long old_msr;
 	char msr_path[32];
 	int retval;
 	int fd;

 	sprintf(msr_path, "/dev/cpu/%d/msr", cpu);
 	fd = open(msr_path, O_RDWR);
 	if (fd < 0) {
 		perror(msr_path);
 		exit(1);
 	}

 	retval = pread(fd, &old_msr, sizeof old_msr, offset);
 	if (retval != sizeof old_msr) {
 		perror("pwrite");
 		printf("pread cpu%d 0x%x = %d\n", cpu, offset, retval);
 		exit(-2);
 	}

 	retval = pwrite(fd, &new_msr, sizeof new_msr, offset);
 	if (retval != sizeof new_msr) {
 		perror("pwrite");
 		printf("pwrite cpu%d 0x%x = %d\n", cpu, offset, retval);
 		exit(-2);
 	}

 	close(fd);

 	return old_msr;
 }

 void print_msr(int cpu)
 {
 	printf("cpu%d: 0x%016llx\n",
 		cpu, get_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS));
 }

 void update_msr(int cpu)
 {
 	unsigned long long previous_msr;

 	previous_msr = put_msr(cpu, new_bias, MSR_IA32_ENERGY_PERF_BIAS);

 	if (verbose)
 		printf("cpu%d  msr0x%x 0x%016llx -> 0x%016llx\n",
 			cpu, MSR_IA32_ENERGY_PERF_BIAS, previous_msr, new_bias);

 	return;
 }

 char *proc_stat = "/proc/stat";
 /*
  * run func() on every cpu in /dev/cpu
  */
 void for_every_cpu(void (func)(int))
 {
 	FILE *fp;
 	int retval;

 	fp = fopen(proc_stat, "r");
 	if (fp == NULL) {
 		perror(proc_stat);
 		exit(1);
 	}

 	retval = fscanf(fp, "cpu %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d\n");
 	if (retval != 0) {
 		perror("/proc/stat format");
 		exit(1);
 	}

 	while (1) {
 		int cpu;

 		retval = fscanf(fp,
 			"cpu%u %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d\n",
 			&cpu);
 		if (retval != 1)
 			break;

 		func(cpu);
 	}
 	fclose(fp);
 }

 int main(int argc, char **argv)
 {
 	cmdline(argc, argv);

 	if (verbose > 1)
 		printf("x86_energy_perf_policy Nov 24, 2010"
 				" - Len Brown <lenb@kernel.org>\n");
 	if (verbose > 1 && !read_only)
 		printf("new_bias %lld\n", new_bias);

 	validate_cpuid();

 	if (cpu != -1) {
 		if (read_only)
 			print_msr(cpu);
 		else
 			update_msr(cpu);
 	} else {
 		if (read_only)
 			for_every_cpu(print_msr);
 		else
 			for_every_cpu(update_msr);
 	}

 	return 0;
 }
	/*
	* x86_energy_perf_policy -- set the energy versus performance
	* policy preference bias on recent X86 processors.
	*/
	/*
	* Copyright (c) 2010, Intel Corporation.
	* Len Brown <len.brown@intel.com>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* This program is distributed in the hope 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.
	*
	* You should have received a copy of the GNU General Public License along with
	* this program; if not, write to the Free Software Foundation, Inc.,
	* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
	*/

	#include <stdio.h>
	#include <unistd.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/resource.h>
	#include <fcntl.h>
	#include <signal.h>
	#include <sys/time.h>
	#include <stdlib.h>
	#include <string.h>

	unsigned int verbose; /* set with -v */
	unsigned int read_only; /* set with -r */
	char *progname;
	unsigned long long new_bias;
	int cpu = -1;

	/*
	* Usage:
	*
	* -c cpu: limit action to a single CPU (default is all CPUs)
	* -v: verbose output (can invoke more than once)
	* -r: read-only, don't change any settings
	*
	* performance
	* Performance is paramount.
	* Unwilling to sacrifice any performance
	* for the sake of energy saving. (hardware default)
	*
	* normal
	* Can tolerate minor performance compromise
	* for potentially significant energy savings.
	* (reasonable default for most desktops and servers)
	*
	* powersave
	* Can tolerate significant performance hit
	* to maximize energy savings.
	*
	* n
	* a numerical value to write to the underlying MSR.
	*/
	void usage(void)
	{
	printf("%s: [-c cpu] [-v] "
	"(-r \| 'performance' \| 'normal' \| 'powersave' \| n)\n",
	progname);
	exit(1);
	}

	#define MSR_IA32_ENERGY_PERF_BIAS 0x000001b0

	#define BIAS_PERFORMANCE 0
	#define BIAS_BALANCE 6
	#define BIAS_POWERSAVE 15

	void cmdline(int argc, char **argv)
	{
	int opt;

	progname = argv[0];

	while ((opt = getopt(argc, argv, "+rvc:")) != -1) {
	switch (opt) {
	case 'c':
	cpu = atoi(optarg);
	break;
	case 'r':
	read_only = 1;
	break;
	case 'v':
	verbose++;
	break;
	default:
	usage();
	}
	}
	/* if -r, then should be no additional optind */
	if (read_only && (argc > optind))
	usage();

	/*
	* if no -r , then must be one additional optind
	*/
	if (!read_only) {

	if (argc != optind + 1) {
	printf("must supply -r or policy param\n");
	usage();
	}

	if (!strcmp("performance", argv[optind])) {
	new_bias = BIAS_PERFORMANCE;
	} else if (!strcmp("normal", argv[optind])) {
	new_bias = BIAS_BALANCE;
	} else if (!strcmp("powersave", argv[optind])) {
	new_bias = BIAS_POWERSAVE;
	} else {
	char *endptr;

	new_bias = strtoull(argv[optind], &endptr, 0);
	if (endptr == argv[optind] \|\|
	new_bias > BIAS_POWERSAVE) {
	fprintf(stderr, "invalid value: %s\n",
	argv[optind]);
	usage();
	}
	}
	}
	}

	/*
	* validate_cpuid()
	* returns on success, quietly exits on failure (make verbose with -v)
	*/
	void validate_cpuid(void)
	{
	unsigned int eax, ebx, ecx, edx, max_level;
	unsigned int fms, family, model, stepping;

	eax = ebx = ecx = edx = 0;

	asm("cpuid" : "=a" (max_level), "=b" (ebx), "=c" (ecx),
	"=d" (edx) : "a" (0));

	if (ebx != 0x756e6547 \|\| edx != 0x49656e69 \|\| ecx != 0x6c65746e) {
	if (verbose)
	fprintf(stderr, "%.4s%.4s%.4s != GenuineIntel",
	(char )&ebx, (char )&edx, (char *)&ecx);
	exit(1);
	}

	asm("cpuid" : "=a" (fms), "=c" (ecx), "=d" (edx) : "a" (1) : "ebx");
	family = (fms >> 8) & 0xf;
	model = (fms >> 4) & 0xf;
	stepping = fms & 0xf;
	if (family == 6 \|\| family == 0xf)
	model += ((fms >> 16) & 0xf) << 4;

	if (verbose > 1)
	printf("CPUID %d levels family:model:stepping "
	"0x%x:%x:%x (%d:%d:%d)\n", max_level,
	family, model, stepping, family, model, stepping);

	if (!(edx & (1 << 5))) {
	if (verbose)
	printf("CPUID: no MSR\n");
	exit(1);
	}

	/*
	* Support for MSR_IA32_ENERGY_PERF_BIAS
	* is indicated by CPUID.06H.ECX.bit3
	*/
	asm("cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (6));
	if (verbose)
	printf("CPUID.06H.ECX: 0x%x\n", ecx);
	if (!(ecx & (1 << 3))) {
	if (verbose)
	printf("CPUID: No MSR_IA32_ENERGY_PERF_BIAS\n");
	exit(1);
	}
	return; /* success */
	}

	unsigned long long get_msr(int cpu, int offset)
	{
	unsigned long long msr;
	char msr_path[32];
	int retval;
	int fd;

	sprintf(msr_path, "/dev/cpu/%d/msr", cpu);
	fd = open(msr_path, O_RDONLY);
	if (fd < 0) {
	printf("Try \"# modprobe msr\"\n");
	perror(msr_path);
	exit(1);
	}

	retval = pread(fd, &msr, sizeof msr, offset);

	if (retval != sizeof msr) {
	printf("pread cpu%d 0x%x = %d\n", cpu, offset, retval);
	exit(-2);
	}
	close(fd);
	return msr;
	}

	unsigned long long put_msr(int cpu, unsigned long long new_msr, int offset)
	{
	unsigned long long old_msr;
	char msr_path[32];
	int retval;
	int fd;

	sprintf(msr_path, "/dev/cpu/%d/msr", cpu);
	fd = open(msr_path, O_RDWR);
	if (fd < 0) {
	perror(msr_path);
	exit(1);
	}

	retval = pread(fd, &old_msr, sizeof old_msr, offset);
	if (retval != sizeof old_msr) {
	perror("pwrite");
	printf("pread cpu%d 0x%x = %d\n", cpu, offset, retval);
	exit(-2);
	}

	retval = pwrite(fd, &new_msr, sizeof new_msr, offset);
	if (retval != sizeof new_msr) {
	perror("pwrite");
	printf("pwrite cpu%d 0x%x = %d\n", cpu, offset, retval);
	exit(-2);
	}

	close(fd);

	return old_msr;
	}

	void print_msr(int cpu)
	{
	printf("cpu%d: 0x%016llx\n",
	cpu, get_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS));
	}

	void update_msr(int cpu)
	{
	unsigned long long previous_msr;

	previous_msr = put_msr(cpu, new_bias, MSR_IA32_ENERGY_PERF_BIAS);

	if (verbose)
	printf("cpu%d msr0x%x 0x%016llx -> 0x%016llx\n",
	cpu, MSR_IA32_ENERGY_PERF_BIAS, previous_msr, new_bias);

	return;
	}

	char *proc_stat = "/proc/stat";
	/*
	* run func() on every cpu in /dev/cpu
	*/
	void for_every_cpu(void (func)(int))
	{
	FILE *fp;
	int retval;

	fp = fopen(proc_stat, "r");
	if (fp == NULL) {
	perror(proc_stat);
	exit(1);
	}

	retval = fscanf(fp, "cpu %d %d %d %d %d %d %d %d %d %d\n");
	if (retval != 0) {
	perror("/proc/stat format");
	exit(1);
	}

	while (1) {
	int cpu;

	retval = fscanf(fp,
	"cpu%u %d %d %d %d %d %d %d %d %d %d\n",
	&cpu);
	if (retval != 1)
	break;

	func(cpu);
	}
	fclose(fp);
	}

	int main(int argc, char **argv)
	{
	cmdline(argc, argv);

	if (verbose > 1)
	printf("x86_energy_perf_policy Nov 24, 2010"
	" - Len Brown <lenb@kernel.org>\n");
	if (verbose > 1 && !read_only)
	printf("new_bias %lld\n", new_bias);

	validate_cpuid();

	if (cpu != -1) {
	if (read_only)
	print_msr(cpu);
	else
	update_msr(cpu);
	} else {
	if (read_only)
	for_every_cpu(print_msr);
	else
	for_every_cpu(update_msr);
	}

	return 0;
	}