@@ -310,7 +310,7 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
* Section 8.4.7.1.1.5 of ACPI 6.1 spec)
*/
policy->min = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.lowest_nonlinear_perf);
- policy->max = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.highest_perf);
+ policy->max = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.nominal_perf);
/*
* Set cpuinfo.min_freq to Lowest to make the full range of performance
@@ -318,7 +318,7 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
* nonlinear perf
*/
policy->cpuinfo.min_freq = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.lowest_perf);
- policy->cpuinfo.max_freq = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.highest_perf);
+ policy->cpuinfo.max_freq = cppc_cpufreq_perf_to_khz(cpu, cpu->perf_caps.nominal_perf);
policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu_num);
policy->shared_type = cpu->shared_type;
@@ -343,6 +343,19 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
cpu->cur_policy = policy;
+ /*
+ * If 'highest_perf' is greater than 'nominal_perf', we assume CPU Boost
+ * is supported.
+ */
+ if (cpu->perf_caps.highest_perf > cpu->perf_caps.nominal_perf) {
+ policy->cpuinfo.boost_max_freq = cppc_cpufreq_perf_to_khz(cpu,
+ cpu->perf_caps.highest_perf);
+ policy->cpuinfo.nonboost_max_freq = cppc_cpufreq_perf_to_khz(cpu,
+ cpu->perf_caps.nominal_perf);
+
+ cpufreq_enable_boost_support();
+ }
+
/* Set policy->cur to max now. The governors will adjust later. */
policy->cur = cppc_cpufreq_perf_to_khz(cpu,
cpu->perf_caps.highest_perf);
To add SW BOOST support for CPPC, we need to get the max frequency of boost mode and non-boost mode. ACPI spec 6.2 section 8.4.7.1 describe the following two CPC registers. "Highest performance is the absolute maximum performance an individual processor may reach, assuming ideal conditions. This performance level may not be sustainable for long durations, and may only be achievable if other platform components are in a specific state; for example, it may require other processors be in an idle state. Nominal Performance is the maximum sustained performance level of the processor, assuming ideal operating conditions. In absence of an external constraint (power, thermal, etc.) this is the performance level the platform is expected to be able to maintain continuously. All processors are expected to be able to sustain their nominal performance state simultaneously." To add SW BOOST support for CPPC, we can use Highest Performance as the max performance in boost mode and Nominal Performance as the max performance in non-boost mode. If the Highest Performance is greater than the Nominal Performance, we assume SW BOOST is supported. The current CPPC driver does not support SW BOOST and use 'Highest Performance' as the max performance the CPU can achieve. 'Nominal Performance' is used to convert 'performance' to 'frequency'. That means, if firmware enable boost and provide a value for Highest Performance which is greater than Nominal Performance, boost feature is enabled by default. Because SW BOOST is disabled by default, so, after this patch, boost feature is disabled by default even if boost is enabled by firmware. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> --- drivers/cpufreq/cppc_cpufreq.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-)