diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/acpi/cppc.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c index f0328ce98a8f..a75dcb382c78 100644 --- a/arch/x86/kernel/acpi/cppc.c +++ b/arch/x86/kernel/acpi/cppc.c @@ -116,6 +116,36 @@ void init_freq_invariance_cppc(void) mutex_unlock(&freq_invariance_lock); } +/* + * Get the highest performance register value. + * @cpu: CPU from which to get highest performance. + * @highest_perf: Return address for highest performance value. + * + * Return: 0 for success, negative error code otherwise. + */ +int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf) +{ + u64 val; + int ret; + + if (cpu_feature_enabled(X86_FEATURE_CPPC)) { + ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &val); + if (ret) + goto out; + + val = AMD_CPPC_HIGHEST_PERF(val); + } else { + ret = cppc_get_highest_perf(cpu, &val); + if (ret) + goto out; + } + + WRITE_ONCE(*highest_perf, (u32)val); +out: + return ret; +} +EXPORT_SYMBOL_GPL(amd_get_highest_perf); + /** * amd_get_boost_ratio_numerator: Get the numerator to use for boost ratio calculation * @cpu: CPU to get numerator for. |