diff options
Diffstat (limited to 'drivers/cpufreq/acpi-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/acpi-cpufreq.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c index fb5712141040..7f38fb55f223 100644 --- a/drivers/cpufreq/acpi-cpufreq.c +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -458,6 +458,43 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, return result; } +unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy, + unsigned int target_freq) +{ + struct acpi_cpufreq_data *data = policy->driver_data; + struct acpi_processor_performance *perf; + struct cpufreq_frequency_table *entry; + unsigned int next_perf_state, next_freq, freq; + + /* + * Find the closest frequency above target_freq. + * + * The table is sorted in the reverse order with respect to the + * frequency and all of the entries are valid (see the initialization). + */ + entry = data->freq_table; + do { + entry++; + freq = entry->frequency; + } while (freq >= target_freq && freq != CPUFREQ_TABLE_END); + entry--; + next_freq = entry->frequency; + next_perf_state = entry->driver_data; + + perf = to_perf_data(data); + if (perf->state == next_perf_state) { + if (unlikely(data->resume)) + data->resume = 0; + else + return next_freq; + } + + data->cpu_freq_write(&perf->control_register, + perf->states[next_perf_state].control); + perf->state = next_perf_state; + return next_freq; +} + static unsigned long acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu) { @@ -821,6 +858,9 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) */ data->resume = 1; + policy->fast_switch_possible = !acpi_pstate_strict && + !(policy_is_shared(policy) && policy->shared_type != CPUFREQ_SHARED_TYPE_ANY); + return result; err_freqfree: @@ -843,6 +883,7 @@ static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy) pr_debug("acpi_cpufreq_cpu_exit\n"); if (data) { + policy->fast_switch_possible = false; policy->driver_data = NULL; acpi_processor_unregister_performance(data->acpi_perf_cpu); free_cpumask_var(data->freqdomain_cpus); @@ -876,6 +917,7 @@ static struct freq_attr *acpi_cpufreq_attr[] = { static struct cpufreq_driver acpi_cpufreq_driver = { .verify = cpufreq_generic_frequency_table_verify, .target_index = acpi_cpufreq_target, + .fast_switch = acpi_cpufreq_fast_switch, .bios_limit = acpi_processor_get_bios_limit, .init = acpi_cpufreq_cpu_init, .exit = acpi_cpufreq_cpu_exit, |