cpupowerutils - cpufrequtils extended with quite some features

CPU power consumption vs performance tuning is no longer
limited to CPU frequency switching anymore: deep sleep states,
traditional dynamic frequency scaling and hidden turbo/boost
frequencies are tied close together and depend on each other.
The first two exist on different architectures like PPC, Itanium and
ARM, the latter (so far) only on X86. On X86 the APU (CPU+GPU) will
only run most efficiently if CPU and GPU has proper power management
in place.

Users and Developers want to have *one* tool to get an overview what
their system supports and to monitor and debug CPU power management
in detail. The tool should compile and work on as many architectures
as possible.

Once this tool stabilizes a bit, it is intended to replace the
Intel-specific tools in tools/power/x86

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

1 files changed, 113 insertions, 0 deletions

diff --git a/tools/power/cpupower/debug/i386/centrino-decode.c b/tools/power/cpupower/debug/i386/centrino-decode.c
new file mode 100644
index 000000000000..7ef24cce4926
--- /dev/null
+++ b/tools/power/cpupower/debug/i386/centrino-decode.c
@@ -0,0 +1,113 @@
+/*
+ *  (C) 2003 - 2004  Dominik Brodowski <linux@dominikbrodowski.de>
+ *
+ *  Licensed under the terms of the GNU GPL License version 2.
+ *
+ * Based on code found in
+ * linux/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.c
+ * and originally developed by Jeremy Fitzhardinge.
+ *
+ * USAGE: simply run it to decode the current settings on CPU 0,
+ *	  or pass the CPU number as argument, or pass the MSR content
+ *	  as argument.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#define MCPU	32
+
+#define MSR_IA32_PERF_STATUS	0x198
+
+static int rdmsr(unsigned int cpu, unsigned int msr,
+		 unsigned int *lo, unsigned int *hi)
+{
+	int fd;
+	char file[20];
+	unsigned long long val;
+	int retval = -1;
+
+	*lo = *hi = 0;
+
+	if (cpu > MCPU)
+		goto err1;
+
+	sprintf(file, "/dev/cpu/%d/msr", cpu);
+	fd = open(file, O_RDONLY);
+
+	if (fd < 0)
+		goto err1;
+
+	if (lseek(fd, msr, SEEK_CUR) == -1)
+		goto err2;
+
+	if (read(fd, &val, 8) != 8)
+		goto err2;
+
+	*lo = (uint32_t )(val & 0xffffffffull);
+	*hi = (uint32_t )(val>>32 & 0xffffffffull);
+
+	retval = 0;
+err2:
+	close(fd);
+err1:
+	return retval;
+}
+
+static void decode (unsigned int msr)
+{
+	unsigned int multiplier;
+	unsigned int mv;
+
+	multiplier = ((msr >> 8) & 0xFF);
+
+	mv = (((msr & 0xFF) * 16) + 700);
+
+	printf("0x%x means multiplier %d @ %d mV\n", msr, multiplier, mv);
+}
+
+static int decode_live(unsigned int cpu)
+{
+	unsigned int lo, hi;
+	int err;
+
+	err = rdmsr(cpu, MSR_IA32_PERF_STATUS, &lo, &hi);
+
+	if (err) {
+		printf("can't get MSR_IA32_PERF_STATUS for cpu %d\n", cpu);
+		printf("Possible trouble: you don't run an Enhanced SpeedStep capable cpu\n");
+		printf("or you are not root, or the msr driver is not present\n");
+		return 1;
+	}
+
+	decode(lo);
+
+	return 0;
+}
+
+int main (int argc, char **argv)
+{
+	unsigned int cpu, mode = 0;
+
+	if (argc < 2)
+		cpu = 0;
+	else {
+		cpu = strtoul(argv[1], NULL, 0);
+		if (cpu >= MCPU)
+			mode = 1;
+	}
+
+	if (mode)
+		decode(cpu);
+	else
+		decode_live(cpu);
+
+	return 0;
+}