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, 145 insertions, 0 deletions

diff --git a/tools/power/cpupower/utils/helpers/cpuid.c b/tools/power/cpupower/utils/helpers/cpuid.c
new file mode 100644
index 000000000000..71021f3bb69d
--- /dev/null
+++ b/tools/power/cpupower/utils/helpers/cpuid.c
@@ -0,0 +1,145 @@
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#include "helpers/helpers.h"
+
+static const char *cpu_vendor_table[X86_VENDOR_MAX] = {
+	"Unknown", "GenuineIntel", "AuthenticAMD",
+};
+
+#if defined(__i386__) || defined(__x86_64__)
+
+/* from gcc */
+#include <cpuid.h>
+
+/*
+ * CPUID functions returning a single datum
+ *
+ * Define unsigned int cpuid_e[abcd]x(unsigned int op)
+ */
+#define cpuid_func(reg)					\
+	unsigned int cpuid_##reg(unsigned int op)	\
+	{						\
+	unsigned int eax, ebx, ecx, edx;		\
+	__cpuid(op, eax, ebx, ecx, edx);		\
+	return reg;					\
+	}
+cpuid_func(eax);
+cpuid_func(ebx);
+cpuid_func(ecx);
+cpuid_func(edx);
+
+#endif /* defined(__i386__) || defined(__x86_64__) */
+
+/* get_cpu_info
+ *
+ * Extract CPU vendor, family, model, stepping info from /proc/cpuinfo
+ *
+ * Returns 0 on success or a negativ error code
+ *
+ * TBD: Should there be a cpuid alternative for this if /proc is not mounted?
+ */
+int get_cpu_info(unsigned int cpu, struct cpupower_cpu_info *cpu_info)
+{
+	FILE *fp;
+	char value[64];
+	unsigned int proc, x;
+	unsigned int unknown = 0xffffff;
+	unsigned int cpuid_level, ext_cpuid_level;
+
+	int ret = -EINVAL;
+
+	cpu_info->vendor		= X86_VENDOR_UNKNOWN;
+	cpu_info->family		= unknown;
+	cpu_info->model			= unknown;
+	cpu_info->stepping		= unknown;
+	cpu_info->caps			= 0;
+
+	fp = fopen("/proc/cpuinfo", "r");
+	if (!fp)
+		return -EIO;
+
+	while (!feof(fp)) {
+		if (!fgets(value, 64, fp))
+			continue;
+		value[63 - 1] = '\0';
+
+		if (!strncmp(value, "processor\t: ", 12)) {
+			sscanf(value, "processor\t: %u", &proc);
+		}
+		if (proc != cpu)
+			continue;
+
+		/* Get CPU vendor */
+		if (!strncmp(value, "vendor_id", 9))
+			for (x = 1; x < X86_VENDOR_MAX; x++) {
+				if (strstr(value, cpu_vendor_table[x]))
+					cpu_info->vendor = x;
+			}
+		/* Get CPU family, etc. */
+		else if (!strncmp(value, "cpu family\t: ", 13)) {
+			sscanf(value, "cpu family\t: %u",
+			       &cpu_info->family);
+		}
+		else if (!strncmp(value, "model\t\t: ", 9)) {
+			sscanf(value, "model\t\t: %u",
+			       &cpu_info->model);
+		}
+		else if (!strncmp(value, "stepping\t: ", 10)) {
+			sscanf(value, "stepping\t: %u",
+			       &cpu_info->stepping);
+
+			/* Exit -> all values must have been set */
+			if (cpu_info->vendor == X86_VENDOR_UNKNOWN ||
+			    cpu_info->family == unknown ||
+			    cpu_info->model == unknown ||
+			    cpu_info->stepping == unknown) {
+				ret = -EINVAL;
+				goto out;
+			}
+
+			ret = 0;
+			goto out;
+		}
+	}
+	ret = -ENODEV;
+out:
+	fclose(fp);
+	/* Get some useful CPU capabilities from cpuid */
+	if (cpu_info->vendor != X86_VENDOR_AMD &&
+	    cpu_info->vendor != X86_VENDOR_INTEL)
+		return ret;
+
+	cpuid_level	= cpuid_eax(0);
+	ext_cpuid_level	= cpuid_eax(0x80000000);
+
+	/* Invariant TSC */
+	if (ext_cpuid_level >= 0x80000007 &&
+	    (cpuid_edx(0x80000007) & (1 << 8)))
+		cpu_info->caps |= CPUPOWER_CAP_INV_TSC;
+
+	/* Aperf/Mperf registers support */
+	if (cpuid_level >= 6 && (cpuid_ecx(6) & 0x1))
+		cpu_info->caps |= CPUPOWER_CAP_APERF;
+
+	/* AMD Boost state enable/disable register */
+	if (cpu_info->vendor == X86_VENDOR_AMD) {
+		if (ext_cpuid_level >= 0x80000007 &&
+		    (cpuid_edx(0x80000007) & (1 << 9)))
+			cpu_info->caps |= CPUPOWER_CAP_AMD_CBP;
+	}
+
+	/* Intel's perf-bias MSR support */
+	if (cpu_info->vendor == X86_VENDOR_INTEL) {
+		if (cpuid_level >= 6 && (cpuid_ecx(6) & (1 << 3)))
+			cpu_info->caps |= CPUPOWER_CAP_PERF_BIAS;
+	}
+
+	/*	printf("ID: %u - Extid: 0x%x - Caps: 0x%llx\n",
+		cpuid_level, ext_cpuid_level, cpu_info->caps);
+	*/
+	return ret;
+}