x86/aperfmperf: Put frequency invariance aperf/mperf data into a struct

Preparation for sharing code with the CPU frequency portion of the
aperf/mperf code.

No functional change.

Signed-off-by: Thomas Gleixner <[e-mail]>
Reviewed-by: Rafael J. Wysocki <[e-mail]>
Acked-by: Peter Zijlstra (Intel) <[e-mail]>
Acked-by: Paul E. McKenney <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/x86/kernel/cpu/aperfmperf.c

···
 
 #include "cpu.h"
 
+struct aperfmperf {
+	u64		aperf;
+	u64		mperf;
+};
+
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct aperfmperf, cpu_samples);
+
 struct aperfmperf_sample {
 	unsigned int	khz;
 	atomic_t	scfpending;
···
 
 DEFINE_STATIC_KEY_FALSE(arch_scale_freq_key);
 
-static DEFINE_PER_CPU(u64, arch_prev_aperf);
-static DEFINE_PER_CPU(u64, arch_prev_mperf);
 static u64 arch_turbo_freq_ratio = SCHED_CAPACITY_SCALE;
 static u64 arch_max_freq_ratio = SCHED_CAPACITY_SCALE;
 
···
 	rdmsrl(MSR_IA32_APERF, aperf);
 	rdmsrl(MSR_IA32_MPERF, mperf);
 
-	this_cpu_write(arch_prev_aperf, aperf);
-	this_cpu_write(arch_prev_mperf, mperf);
+	this_cpu_write(cpu_samples.aperf, aperf);
+	this_cpu_write(cpu_samples.mperf, mperf);
 }
 
 #ifdef CONFIG_PM_SLEEP
···
 
 void arch_scale_freq_tick(void)
 {
-	u64 freq_scale;
-	u64 aperf, mperf;
-	u64 acnt, mcnt;
+	struct aperfmperf *s = this_cpu_ptr(&cpu_samples);
+	u64 aperf, mperf, acnt, mcnt, freq_scale;
 
 	if (!arch_scale_freq_invariant())
 		return;
···
 	rdmsrl(MSR_IA32_APERF, aperf);
 	rdmsrl(MSR_IA32_MPERF, mperf);
 
-	acnt = aperf - this_cpu_read(arch_prev_aperf);
-	mcnt = mperf - this_cpu_read(arch_prev_mperf);
+	acnt = aperf - s->aperf;
+	mcnt = mperf - s->mperf;
 
-	this_cpu_write(arch_prev_aperf, aperf);
-	this_cpu_write(arch_prev_mperf, mperf);
+	s->aperf = aperf;
+	s->mperf = mperf;
 
 	if (check_shl_overflow(acnt, 2*SCHED_CAPACITY_SHIFT, &acnt))
 		goto error;