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Commit a2fed573 authored by Mark Langsdorf's avatar Mark Langsdorf Committed by H. Peter Anvin
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x86, cpufreq: Add APERF/MPERF support for AMD processors 



Starting with model 10 of Family 0x10, AMD processors may have
support for APERF/MPERF.  Add support for identifying it and using
it within cpufreq.  Move the APERF/MPERF functions out of the
acpi-cpufreq code and into their own file so they can easily be
shared.

Signed-off-by: default avatarMark Langsdorf <mark.langsdorf@amd.com>
LKML-Reference: <20100401141956.GA1930@aftab>
Signed-off-by: default avatarBorislav Petkov <borislav.petkov@amd.com>
Reviewed-by: default avatarThomas Renninger <trenn@suse.de>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent d65ad45c

arch/x86/kernel/cpu/cpufreq/Makefile

+2 −2
Original line number Diff line number Diff line
@@ -2,8 +2,8 @@ 
# K8 systems. ACPI is preferred to all other hardware-specific drivers.

# speedstep-* is preferred over p4-clockmod.



obj-$(CONFIG_X86_POWERNOW_K8)		+= powernow-k8.o

obj-$(CONFIG_X86_ACPI_CPUFREQ)		+= acpi-cpufreq.o

obj-$(CONFIG_X86_POWERNOW_K8)		+= powernow-k8.o mperf.o

obj-$(CONFIG_X86_ACPI_CPUFREQ)		+= acpi-cpufreq.o mperf.o

obj-$(CONFIG_X86_PCC_CPUFREQ)		+= pcc-cpufreq.o

obj-$(CONFIG_X86_POWERNOW_K6)		+= powernow-k6.o

obj-$(CONFIG_X86_POWERNOW_K7)		+= powernow-k7.o

arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c

+2 −42
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ 
#include <asm/msr.h>

#include <asm/processor.h>

#include <asm/cpufeature.h>

#include "mperf.h"



#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \

		"acpi-cpufreq", msg)
@@ -70,8 +71,6 @@ struct acpi_cpufreq_data { 


static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);



static DEFINE_PER_CPU(struct aperfmperf, acfreq_old_perf);



/* acpi_perf_data is a pointer to percpu data. */

static struct acpi_processor_performance *acpi_perf_data;
@@ -239,45 +238,6 @@ static u32 get_cur_val(const struct cpumask *mask) 
	return cmd.val;

}



/* Called via smp_call_function_single(), on the target CPU */

static void read_measured_perf_ctrs(void *_cur)

{

	struct aperfmperf *am = _cur;



	get_aperfmperf(am);

}



/*

 * Return the measured active (C0) frequency on this CPU since last call

 * to this function.

 * Input: cpu number

 * Return: Average CPU frequency in terms of max frequency (zero on error)

 *

 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance

 * over a period of time, while CPU is in C0 state.

 * IA32_MPERF counts at the rate of max advertised frequency

 * IA32_APERF counts at the rate of actual CPU frequency

 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and

 * no meaning should be associated with absolute values of these MSRs.

 */

static unsigned int get_measured_perf(struct cpufreq_policy *policy,

				      unsigned int cpu)

{

	struct aperfmperf perf;

	unsigned long ratio;

	unsigned int retval;



	if (smp_call_function_single(cpu, read_measured_perf_ctrs, &perf, 1))

		return 0;



	ratio = calc_aperfmperf_ratio(&per_cpu(acfreq_old_perf, cpu), &perf);

	per_cpu(acfreq_old_perf, cpu) = perf;



	retval = (policy->cpuinfo.max_freq * ratio) >> APERFMPERF_SHIFT;



	return retval;

}



static unsigned int get_cur_freq_on_cpu(unsigned int cpu)

{

	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
@@ -701,7 +661,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) 


	/* Check for APERF/MPERF support in hardware */

	if (cpu_has(c, X86_FEATURE_APERFMPERF))

		acpi_cpufreq_driver.getavg = get_measured_perf;

		acpi_cpufreq_driver.getavg = cpufreq_get_measured_perf;



	dprintk("CPU%u - ACPI performance management activated.\n", cpu);

	for (i = 0; i < perf->state_count; i++)

arch/x86/kernel/cpu/cpufreq/mperf.c

0 → 100644
+51 −0
Original line number Diff line number Diff line 
#include <linux/kernel.h>

#include <linux/smp.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/cpufreq.h>

#include <linux/slab.h>



#include "mperf.h"



static DEFINE_PER_CPU(struct aperfmperf, acfreq_old_perf);



/* Called via smp_call_function_single(), on the target CPU */

static void read_measured_perf_ctrs(void *_cur)

{

	struct aperfmperf *am = _cur;



	get_aperfmperf(am);

}



/*

 * Return the measured active (C0) frequency on this CPU since last call

 * to this function.

 * Input: cpu number

 * Return: Average CPU frequency in terms of max frequency (zero on error)

 *

 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance

 * over a period of time, while CPU is in C0 state.

 * IA32_MPERF counts at the rate of max advertised frequency

 * IA32_APERF counts at the rate of actual CPU frequency

 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and

 * no meaning should be associated with absolute values of these MSRs.

 */

unsigned int cpufreq_get_measured_perf(struct cpufreq_policy *policy,

					unsigned int cpu)

{

	struct aperfmperf perf;

	unsigned long ratio;

	unsigned int retval;



	if (smp_call_function_single(cpu, read_measured_perf_ctrs, &perf, 1))

		return 0;



	ratio = calc_aperfmperf_ratio(&per_cpu(acfreq_old_perf, cpu), &perf);

	per_cpu(acfreq_old_perf, cpu) = perf;



	retval = (policy->cpuinfo.max_freq * ratio) >> APERFMPERF_SHIFT;



	return retval;

}

EXPORT_SYMBOL_GPL(cpufreq_get_measured_perf);

MODULE_LICENSE("GPL");

arch/x86/kernel/cpu/cpufreq/mperf.h

0 → 100644
+9 −0
Original line number Diff line number Diff line 
/*

 *  (c) 2010 Advanced Micro Devices, Inc.

 *  Your use of this code is subject to the terms and conditions of the

 *  GNU general public license version 2. See "COPYING" or

 *  http://www.gnu.org/licenses/gpl.html

 */



unsigned int cpufreq_get_measured_perf(struct cpufreq_policy *policy,

					unsigned int cpu);

arch/x86/kernel/cpu/cpufreq/powernow-k8.c

+8 −0
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ 
#define PFX "powernow-k8: "

#define VERSION "version 2.20.00"

#include "powernow-k8.h"

#include "mperf.h"



/* serialize freq changes  */

static DEFINE_MUTEX(fidvid_mutex);
@@ -57,6 +58,8 @@ static int cpu_family = CPU_OPTERON; 
static bool cpb_capable, cpb_enabled;

static struct msr __percpu *msrs;



static struct cpufreq_driver cpufreq_amd64_driver;



#ifndef CONFIG_SMP

static inline const struct cpumask *cpu_core_mask(int cpu)

{
@@ -1251,6 +1254,7 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol) 
	struct powernow_k8_data *data;

	struct init_on_cpu init_on_cpu;

	int rc;

	struct cpuinfo_x86 *c = &cpu_data(pol->cpu);



	if (!cpu_online(pol->cpu))

		return -ENODEV;
@@ -1325,6 +1329,10 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol) 
		return -EINVAL;

	}



	/* Check for APERF/MPERF support in hardware */

	if (cpu_has(c, X86_FEATURE_APERFMPERF))

		cpufreq_amd64_driver.getavg = cpufreq_get_measured_perf;



	cpufreq_frequency_table_get_attr(data->powernow_table, pol->cpu);



	if (cpu_family == CPU_HW_PSTATE)