1 files changed, 88 insertions, 0 deletions
diff --git a/util/msrtool/linux.c b/util/msrtool/linux.c
new file mode 100644
index 0000000000..efd3087061
--- /dev/null
+++ b/util/msrtool/linux.c
@@ -0,0 +1,88 @@
+/*
+ * This file is part of msrtool.
+ *
+ * Copyright (c) 2008 Peter Stuge <peter@stuge.se>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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 <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#include "msrtool.h"
+
+static int msr_fd[MAX_CORES] = {-1, -1, -1, -1, -1, -1, -1, -1};
+
+int linux_probe(const struct sysdef *system) {
+	struct stat st;
+	return 0 == stat("/dev/cpu/0/msr", &st);
+}
+
+int linux_open(uint8_t cpu, enum SysModes mode) {
+	int fmode;
+	char fn[32];
+	switch (mode) {
+	case SYS_RDWR:
+		fmode = O_RDWR;
+		break;
+	case SYS_WRONLY:
+		fmode = O_WRONLY;
+		break;
+	case SYS_RDONLY:
+	default:
+		fmode = O_RDONLY;
+		break;
+	}
+	if (cpu >= MAX_CORES) {
+		fprintf(stderr, "%s: only cores 0-%d are supported. requested=%d\n", __func__, MAX_CORES, cpu);
+		return 0;
+	}
+	if (snprintf(fn, sizeof(fn), "/dev/cpu/%d/msr", cpu) == -1) {
+		fprintf(stderr, "%s: snprintf: %s\n", __func__, strerror(errno));
+		return 0;
+	}
+	msr_fd[cpu] = open(fn, fmode);
+	if (-1 == msr_fd[cpu]) {
+		fprintf(stderr, "open(%s): %s\n", fn, strerror(errno));
+		return 0;
+	}
+	return 1;
+}
+
+int linux_close(uint8_t cpu) {
+	int ret;
+	if (cpu >= MAX_CORES) {
+		fprintf(stderr, "%s: only cores 0-%d are supported. requested=%d\n", __func__, MAX_CORES, cpu);
+		return 0;
+	}
+	ret = close(msr_fd[cpu]);
+	msr_fd[cpu] = 0;
+	return 0 == ret;
+}
+
+int linux_rdmsr(uint8_t cpu, uint32_t addr, struct msr *val) {
+	if (lseek(msr_fd[cpu], addr, SEEK_SET) == -1) {
+		SYSERROR(lseek, addr);
+		return 0;
+	}
+	if (read(msr_fd[cpu], val, 8) != 8) {
+		SYSERROR(read, addr);
+		return 0;
+	}
+	return 1;
+}