Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5cbc19a9 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

x86: Add generic aperf/mperf code 



Move some of the aperf/mperf code out from the cpufreq driver
thingy so that other people can enjoy it too.

Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Yanmin <yanmin_zhang@linux.intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: cpufreq@vger.kernel.org
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent a8303aaf

arch/x86/include/asm/processor.h

+30 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ struct mm_struct; 
#include <linux/cpumask.h>

#include <linux/cache.h>

#include <linux/threads.h>

#include <linux/math64.h>

#include <linux/init.h>



/*
@@ -1020,4 +1021,33 @@ extern void start_thread(struct pt_regs *regs, unsigned long new_ip, 
extern int get_tsc_mode(unsigned long adr);

extern int set_tsc_mode(unsigned int val);



struct aperfmperf {

	u64 aperf, mperf;

};



static inline void get_aperfmperf(struct aperfmperf *am)

{

	WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_APERFMPERF));



	rdmsrl(MSR_IA32_APERF, am->aperf);

	rdmsrl(MSR_IA32_MPERF, am->mperf);

}



#define APERFMPERF_SHIFT 10



static inline

unsigned long calc_aperfmperf_ratio(struct aperfmperf *old,

				    struct aperfmperf *new)

{

	u64 aperf = new->aperf - old->aperf;

	u64 mperf = new->mperf - old->mperf;

	unsigned long ratio = aperf;



	mperf >>= APERFMPERF_SHIFT;

	if (mperf)

		ratio = div64_u64(aperf, mperf);



	return ratio;

}



#endif /* _ASM_X86_PROCESSOR_H */

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

+9 −70
Original line number Diff line number Diff line
@@ -70,11 +70,7 @@ struct acpi_cpufreq_data { 


static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);



struct acpi_msr_data {

	u64 saved_aperf, saved_mperf;

};



static DEFINE_PER_CPU(struct acpi_msr_data, msr_data);

static DEFINE_PER_CPU(struct aperfmperf, old_perf);



DEFINE_TRACE(power_mark);
@@ -243,23 +239,12 @@ static u32 get_cur_val(const struct cpumask *mask) 
	return cmd.val;

}



struct perf_pair {

	union {

		struct {

			u32 lo;

			u32 hi;

		} split;

		u64 whole;

	} aperf, mperf;

};



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

static void read_measured_perf_ctrs(void *_cur)

{

	struct perf_pair *cur = _cur;

	struct aperfmperf *am = _cur;



	rdmsr(MSR_IA32_APERF, cur->aperf.split.lo, cur->aperf.split.hi);

	rdmsr(MSR_IA32_MPERF, cur->mperf.split.lo, cur->mperf.split.hi);

	get_aperfmperf(am);

}



/*
@@ -278,63 +263,17 @@ static void read_measured_perf_ctrs(void *_cur) 
static unsigned int get_measured_perf(struct cpufreq_policy *policy,

				      unsigned int cpu)

{

	struct perf_pair readin, cur;

	unsigned int perf_percent;

	struct aperfmperf perf;

	unsigned long ratio;

	unsigned int retval;



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

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

		return 0;



	cur.aperf.whole = readin.aperf.whole -

				per_cpu(msr_data, cpu).saved_aperf;

	cur.mperf.whole = readin.mperf.whole -

				per_cpu(msr_data, cpu).saved_mperf;

	per_cpu(msr_data, cpu).saved_aperf = readin.aperf.whole;

	per_cpu(msr_data, cpu).saved_mperf = readin.mperf.whole;



#ifdef __i386__

	/*

	 * We dont want to do 64 bit divide with 32 bit kernel

	 * Get an approximate value. Return failure in case we cannot get

	 * an approximate value.

	 */

	if (unlikely(cur.aperf.split.hi || cur.mperf.split.hi)) {

		int shift_count;

		u32 h;



		h = max_t(u32, cur.aperf.split.hi, cur.mperf.split.hi);

		shift_count = fls(h);



		cur.aperf.whole >>= shift_count;

		cur.mperf.whole >>= shift_count;

	}



	if (((unsigned long)(-1) / 100) < cur.aperf.split.lo) {

		int shift_count = 7;

		cur.aperf.split.lo >>= shift_count;

		cur.mperf.split.lo >>= shift_count;

	}



	if (cur.aperf.split.lo && cur.mperf.split.lo)

		perf_percent = (cur.aperf.split.lo * 100) / cur.mperf.split.lo;

	else

		perf_percent = 0;



#else

	if (unlikely(((unsigned long)(-1) / 100) < cur.aperf.whole)) {

		int shift_count = 7;

		cur.aperf.whole >>= shift_count;

		cur.mperf.whole >>= shift_count;

	}



	if (cur.aperf.whole && cur.mperf.whole)

		perf_percent = (cur.aperf.whole * 100) / cur.mperf.whole;

	else

		perf_percent = 0;



#endif

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

	per_cpu(old_perf, cpu) = perf;



	retval = (policy->cpuinfo.max_freq * perf_percent) / 100;

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



	return retval;

}