From: Venkatesh Pallipadi Date: Mon, 6 Apr 2009 18:26:08 +0000 (-0700) Subject: ACPI x86: Make aperf/mperf MSR access in acpi_cpufreq read_only X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=18b2646fe3babeb40b34a0c1751e0bf5adfdc64c;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git ACPI x86: Make aperf/mperf MSR access in acpi_cpufreq read_only Do not write zeroes to APERF and MPERF by ondemand governor. With this change, other users can share these MSRs for reads. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Len Brown --- diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 340bdbebba07..9d3af380c6bd 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -68,6 +68,7 @@ struct acpi_cpufreq_data { unsigned int max_freq; unsigned int resume; unsigned int cpu_feature; + u64 saved_aperf, saved_mperf; }; static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data); @@ -259,9 +260,6 @@ static long read_measured_perf_ctrs(void *_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); - wrmsr(MSR_IA32_APERF, 0, 0); - wrmsr(MSR_IA32_MPERF, 0, 0); - return 0; } @@ -281,13 +279,20 @@ static long read_measured_perf_ctrs(void *_cur) static unsigned int get_measured_perf(struct cpufreq_policy *policy, unsigned int cpu) { - struct perf_pair cur; + struct perf_pair readin, cur; unsigned int perf_percent; unsigned int retval; - if (!work_on_cpu(cpu, read_measured_perf_ctrs, &cur)) + if (!work_on_cpu(cpu, read_measured_perf_ctrs, &readin)) return 0; + cur.aperf.whole = readin.aperf.whole - + per_cpu(drv_data, cpu)->saved_aperf; + cur.mperf.whole = readin.mperf.whole - + per_cpu(drv_data, cpu)->saved_mperf; + per_cpu(drv_data, cpu)->saved_aperf = readin.aperf.whole; + per_cpu(drv_data, cpu)->saved_mperf = readin.mperf.whole; + #ifdef __i386__ /* * We dont want to do 64 bit divide with 32 bit kernel