Attachment 626015 Details for Bug 715485 – wrmsr.c

wrmsr.c

wrmsr.c (text/x-csrc), 3.54 KB, created by Len Brown on 2012-10-12 14:05:43 UTC

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Creator: Len Brown

Created: 2012-10-12 14:05:43 UTC

Size: 3.54 KB

patch

obsolete

>/* ----------------------------------------------------------------------- *
> *
> *   Copyright 2000 Transmeta Corporation - All Rights Reserved
> *   Copyright 2004-2008 H. Peter Anvin - All Rights Reserved
> *
> *   This program is free software; you can redistribute it and/or modify
> *   it under the terms of the GNU General Public License as published by
> *   the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
> *   Boston MA 02110-1301, USA; either version 2 of the License, or
> *   (at your option) any later version; incorporated herein by reference.
> *
> * ----------------------------------------------------------------------- */
>
>/*
> * wrmsr.c
> *
> * Utility to write to an MSR.
> */
>
>#include <errno.h>
>#include <stdio.h>
>#include <fcntl.h>
>#include <unistd.h>
>#include <stdlib.h>
>#include <getopt.h>
>#include <inttypes.h>
>#include <sys/types.h>
>
>#include "version.h"
>
>static const struct option long_options[] = {
>	{"help",	0, 0, 'h'},
>	{"version",	0, 0, 'V'},
>	{"all",		0, 0, 'a'},
>	{"processor",	1, 0, 'p'},
>	{"cpu",		1, 0, 'p'},
>	{0, 0, 0, 0}
>};
>static const char short_options[] = "hVap:";
>
>static const char *proc_stat = "/proc/stat";
>const char *program;
>
>static void usage(void)
>{
>	fprintf(stderr, "Usage: %s [options] regno value...\n"
>		"  --help         -h  Print this help\n"
>		"  --version      -V  Print current version\n"
>		"  --all          -a  all processors\n"
>		"  --processor #  -p  Select processor number (default 0)\n",
>		program);
>}
>
>static void wrmsr_on_cpu(uint32_t reg, uint64_t data, int cpu)
>{
>	int fd;
>	char msr_file_name[64];
>
>	sprintf(msr_file_name, "/dev/cpu/%d/msr", cpu);
>	fd = open(msr_file_name, O_WRONLY);
>	if (fd < 0) {
>		if (errno == ENXIO) {
>			fprintf(stderr, "wrmsr: No CPU %d\n", cpu);
>			exit(2);
>		} else if (errno == EIO) {
>			fprintf(stderr, "wrmsr: CPU %d doesn't support MSRs\n",
>				cpu);
>			exit(3);
>		} else {
>			perror("wrmsr: open");
>			exit(127);
>		}
>	}
>	if (pwrite(fd, &data, sizeof data, reg) != sizeof data) {
>		if (errno == EIO) {
>			fprintf(stderr,
>				"wrmsr: CPU %d cannot set MSR "
>				"0x%08"PRIx32" to 0x%016"PRIx64"\n",
>				cpu, reg, data);
>			exit(4);
>		} else {
>			perror("wrmsr: pwrite");
>			exit(127);
>		}
>	}
>	close(fd);
>}
>
>
>static void wrmsr_on_all_cpus(uint32_t reg, uint64_t data)
>{
>	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);
>	}
>
>	for (;;) {
>		int cpu;
>
>		retval = fscanf(fp, "cpu%u %*d %*d %*d %*d %*d %*d %*d %*d "
>			"%*d %*d\n", &cpu);
>		if (retval != 1)
>			return;
>
>		wrmsr_on_cpu(reg, data, cpu);
>	}
>	fclose(fp);
>}
>
>int main(int argc, char *argv[])
>{
>	uint32_t reg;
>	uint64_t data;
>	int c;
>	int cpu = 0;
>	unsigned long arg;
>	char *endarg;
>
>	program = argv[0];
>
>	while ((c = getopt_long(argc, argv, short_options,
>				long_options, NULL)) != -1) {
>		switch (c) {
>		case 'h':
>			usage();
>			exit(0);
>		case 'V':
>			fprintf(stderr, "%s: version %s\n", program,
>				VERSION_STRING);
>			exit(0);
>		case 'a':
>			cpu = -1;
>			break;
>		case 'p':
>			arg = strtoul(optarg, &endarg, 0);
>			if (*endarg || arg > 255) {
>				usage();
>				exit(127);
>			}
>			cpu = (int)arg;
>			break;
>		default:
>			usage();
>			exit(127);
>		}
>	}
>
>	if (optind > argc - 2) {
>		/* Should have at least two arguments */
>		usage();
>		exit(127);
>	}
>
>	reg = strtoul(argv[optind++], NULL, 0);
>
>	while (optind < argc) {
>		data = strtoull(argv[optind++], NULL, 0);
>		if (cpu == -1)
>			wrmsr_on_all_cpus(reg, data);
>		else
>			wrmsr_on_cpu(reg, data, cpu);
>	}
>	exit(0);
>}

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Attachments on bug 715485: 506108 | 509574 | 585981 | 585982 | 625706 | 625707 | 626014 | 626015 | 627002