From 27e954c241673d2437448bd8bf0eaa7cd81a4b15 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Rafa=C5=82=20Bilski?= Date: Thu, 21 Jul 2011 22:11:29 +0100 Subject: [CPUFREQ] e_powersaver: Check BIOS limit for CPU frequency MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Call ACPI function to get BIOS limit for CPU frequency. Fail if processor would like to run at higher frequency. Allow user to ignore BIOS limit. eps: Detected VIA Model D C7-M eps: Current voltage = 1084mV eps: Current multiplier = 16 eps: Highest voltage = 1084mV eps: Highest multiplier = 16 eps: Lowest voltage = 844mV eps: Lowest multiplier = 4 eps: ACPI limit 1.60GHz Signed-off-by: Rafał Bilski Signed-off-by: Dave Jones --- drivers/cpufreq/e_powersaver.c | 76 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) (limited to 'drivers/cpufreq') diff --git a/drivers/cpufreq/e_powersaver.c b/drivers/cpufreq/e_powersaver.c index 84661c54a74c..2882d40a3084 100644 --- a/drivers/cpufreq/e_powersaver.c +++ b/drivers/cpufreq/e_powersaver.c @@ -19,6 +19,11 @@ #include #include +#if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE +#include +#include +#endif + #define EPS_BRAND_C7M 0 #define EPS_BRAND_C7 1 #define EPS_BRAND_EDEN 2 @@ -27,6 +32,9 @@ struct eps_cpu_data { u32 fsb; +#if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE + u32 bios_limit; +#endif struct cpufreq_frequency_table freq_table[]; }; @@ -36,6 +44,46 @@ static struct eps_cpu_data *eps_cpu[NR_CPUS]; static int freq_failsafe_off; static int voltage_failsafe_off; +#if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE +static int ignore_acpi_limit; + +static struct acpi_processor_performance *eps_acpi_cpu_perf; + +/* Minimum necessary to get acpi_processor_get_bios_limit() working */ +static int eps_acpi_init(void) +{ + eps_acpi_cpu_perf = kzalloc(sizeof(struct acpi_processor_performance), + GFP_KERNEL); + if (!eps_acpi_cpu_perf) + return -ENOMEM; + + if (!zalloc_cpumask_var(&eps_acpi_cpu_perf->shared_cpu_map, + GFP_KERNEL)) { + kfree(eps_acpi_cpu_perf); + eps_acpi_cpu_perf = NULL; + return -ENOMEM; + } + + if (acpi_processor_register_performance(eps_acpi_cpu_perf, 0)) { + free_cpumask_var(eps_acpi_cpu_perf->shared_cpu_map); + kfree(eps_acpi_cpu_perf); + eps_acpi_cpu_perf = NULL; + return -EIO; + } + return 0; +} + +static int eps_acpi_exit(struct cpufreq_policy *policy) +{ + if (eps_acpi_cpu_perf) { + acpi_processor_unregister_performance(eps_acpi_cpu_perf, 0); + free_cpumask_var(eps_acpi_cpu_perf->shared_cpu_map); + kfree(eps_acpi_cpu_perf); + eps_acpi_cpu_perf = NULL; + } + return 0; +} +#endif static unsigned int eps_get(unsigned int cpu) { @@ -168,6 +216,9 @@ static int eps_cpu_init(struct cpufreq_policy *policy) int k, step, voltage; int ret; int states; +#if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE + unsigned int limit; +#endif if (policy->cpu != 0) return -ENODEV; @@ -271,6 +322,24 @@ static int eps_cpu_init(struct cpufreq_policy *policy) /* Calc FSB speed */ fsb = cpu_khz / current_multiplier; + +#if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE + /* Check for ACPI processor speed limit */ + if (!ignore_acpi_limit && !eps_acpi_init()) { + if (!acpi_processor_get_bios_limit(policy->cpu, &limit)) { + printk(KERN_INFO "eps: ACPI limit %u.%uGHz\n", + limit/1000000, + (limit%1000000)/10000); + eps_acpi_exit(policy); + /* Check if max_multiplier is in BIOS limits */ + if (limit && max_multiplier * fsb > limit) { + printk(KERN_INFO "eps: Aborting.\n"); + return -EINVAL; + } + } + } +#endif + /* Calc number of p-states supported */ if (brand == EPS_BRAND_C7M) states = max_multiplier - min_multiplier + 1; @@ -287,6 +356,9 @@ static int eps_cpu_init(struct cpufreq_policy *policy) /* Copy basic values */ centaur->fsb = fsb; +#if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE + centaur->bios_limit = limit; +#endif /* Fill frequency and MSR value table */ f_table = ¢aur->freq_table[0]; @@ -377,6 +449,10 @@ module_param(freq_failsafe_off, int, 0644); MODULE_PARM_DESC(freq_failsafe_off, "Disable current vs max frequency check"); module_param(voltage_failsafe_off, int, 0644); MODULE_PARM_DESC(voltage_failsafe_off, "Disable current vs max voltage check"); +#if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE +module_param(ignore_acpi_limit, int, 0644); +MODULE_PARM_DESC(ignore_acpi_limit, "Don't check ACPI's processor speed limit"); +#endif MODULE_AUTHOR("Rafal Bilski "); MODULE_DESCRIPTION("Enhanced PowerSaver driver for VIA C7 CPU's."); -- cgit v1.2.3