| Message ID | 1343305724-2809-7-git-send-email-andre.przywara@amd.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Thursday, July 26, 2012, Andre Przywara wrote: > The powernow-k8 driver supported a sysfs knob called "cpb", which was > instantiated per CPU, but actually acted globally for the whole > system. To keep some compatibility with this feature, we re-introduce > this behavior here, but: > a) only enable it on AMD CPUs and > b) protect it with a Kconfig switch > > I'd like to consider this feature obsolete. Lets keep it around for > some kernel versions and then phase it out. You're not keeing it, but moving it to a different driver. :-) Why don't we ask the users who really really want it to use powernow-k8 instead? Rafael > Signed-off-by: Andre Przywara <andre.przywara@amd.com> > --- > drivers/cpufreq/Kconfig.x86 | 12 ++++++++++ > drivers/cpufreq/acpi-cpufreq.c | 46 ++++++++++++++++++++++++++++++++++++++- > 2 files changed, 56 insertions(+), 2 deletions(-) > > diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86 > index 78ff7ee..d2f2320 100644 > --- a/drivers/cpufreq/Kconfig.x86 > +++ b/drivers/cpufreq/Kconfig.x86 > @@ -32,6 +32,18 @@ config X86_ACPI_CPUFREQ > > If in doubt, say N. > > +config X86_ACPI_CPUFREQ_CPB > + default y > + bool "Legacy cpb sysfs knob support for AMD CPUs" > + depends on X86_ACPI_CPUFREQ && CPU_SUP_AMD > + help > + The powernow-k8 driver used to provide a sysfs knob called "cpb" > + to disable the Core Performance Boosting feature of AMD CPUs. This > + file has now been superseeded by the more generic "boost" entry. > + > + By enabling this option the acpi_cpufreq driver provides the old > + entry in addition to the new boost ones, for compatibility reasons. > + > config ELAN_CPUFREQ > tristate "AMD Elan SC400 and SC410" > select CPU_FREQ_TABLE > diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c > index ca41aaa..1ba4cac 100644 > --- a/drivers/cpufreq/acpi-cpufreq.c > +++ b/drivers/cpufreq/acpi-cpufreq.c > @@ -131,8 +131,7 @@ static void boost_set_msrs(bool enable, const struct cpumask *cpumask) > wrmsr_on_cpus(cpumask, msr_addr, msrs); > } > > -static ssize_t store_global_boost(struct kobject *kobj, struct attribute *attr, > - const char *buf, size_t count) > +static ssize_t _store_boost(const char *buf, size_t count) > { > int ret; > unsigned long val = 0; > @@ -159,6 +158,12 @@ static ssize_t store_global_boost(struct kobject *kobj, struct attribute *attr, > return count; > } > > +static ssize_t store_global_boost(struct kobject *kobj, struct attribute *attr, > + const char *buf, size_t count) > +{ > + return _store_boost(buf, count); > +} > + > static ssize_t show_global_boost(struct kobject *kobj, > struct attribute *attr, char *buf) > { > @@ -169,6 +174,21 @@ static struct global_attr global_boost = __ATTR(boost, 0644, > show_global_boost, > store_global_boost); > > +#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB > +static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf, > + size_t count) > +{ > + return _store_boost(buf, count); > +} > + > +static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf) > +{ > + return sprintf(buf, "%u\n", boost_enabled); > +} > + > +static struct freq_attr cpb = __ATTR(cpb, 0644, show_cpb, store_cpb); > +#endif > + > static int check_est_cpu(unsigned int cpuid) > { > struct cpuinfo_x86 *cpu = &cpu_data(cpuid); > @@ -887,6 +907,7 @@ static int acpi_cpufreq_resume(struct cpufreq_policy *policy) > > static struct freq_attr *acpi_cpufreq_attr[] = { > &cpufreq_freq_attr_scaling_available_freqs, > + NULL, /* this is a placeholder for cpb, do not remove */ > NULL, > }; > > @@ -958,6 +979,27 @@ static int __init acpi_cpufreq_init(void) > if (ret) > return ret; > > +#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB > + /* this is a sysfs file with a strange name and an even stranger > + * semantic - per CPU instantiation, but system global effect. > + * Lets enable it only on AMD CPUs for compatibility reasons and > + * only if configured. This is considered legacy code, which > + * will probably be removed at some point in the future. > + */ > + if (check_amd_hwpstate_cpu(0)) { > + struct freq_attr **iter; > + > + pr_debug("adding sysfs entry for cpb\n"); > + > + for (iter = acpi_cpufreq_attr; *iter != NULL; iter++) > + ; > + > + /* make sure there is a terminator behind it */ > + if (iter[1] == NULL) > + *iter = &cpb; > + } > +#endif > + > ret = cpufreq_register_driver(&acpi_cpufreq_driver); > if (ret) > free_acpi_perf_data(); > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86 index 78ff7ee..d2f2320 100644 --- a/drivers/cpufreq/Kconfig.x86 +++ b/drivers/cpufreq/Kconfig.x86 @@ -32,6 +32,18 @@ config X86_ACPI_CPUFREQ If in doubt, say N. +config X86_ACPI_CPUFREQ_CPB + default y + bool "Legacy cpb sysfs knob support for AMD CPUs" + depends on X86_ACPI_CPUFREQ && CPU_SUP_AMD + help + The powernow-k8 driver used to provide a sysfs knob called "cpb" + to disable the Core Performance Boosting feature of AMD CPUs. This + file has now been superseeded by the more generic "boost" entry. + + By enabling this option the acpi_cpufreq driver provides the old + entry in addition to the new boost ones, for compatibility reasons. + config ELAN_CPUFREQ tristate "AMD Elan SC400 and SC410" select CPU_FREQ_TABLE diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c index ca41aaa..1ba4cac 100644 --- a/drivers/cpufreq/acpi-cpufreq.c +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -131,8 +131,7 @@ static void boost_set_msrs(bool enable, const struct cpumask *cpumask) wrmsr_on_cpus(cpumask, msr_addr, msrs); } -static ssize_t store_global_boost(struct kobject *kobj, struct attribute *attr, - const char *buf, size_t count) +static ssize_t _store_boost(const char *buf, size_t count) { int ret; unsigned long val = 0; @@ -159,6 +158,12 @@ static ssize_t store_global_boost(struct kobject *kobj, struct attribute *attr, return count; } +static ssize_t store_global_boost(struct kobject *kobj, struct attribute *attr, + const char *buf, size_t count) +{ + return _store_boost(buf, count); +} + static ssize_t show_global_boost(struct kobject *kobj, struct attribute *attr, char *buf) { @@ -169,6 +174,21 @@ static struct global_attr global_boost = __ATTR(boost, 0644, show_global_boost, store_global_boost); +#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB +static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf, + size_t count) +{ + return _store_boost(buf, count); +} + +static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf) +{ + return sprintf(buf, "%u\n", boost_enabled); +} + +static struct freq_attr cpb = __ATTR(cpb, 0644, show_cpb, store_cpb); +#endif + static int check_est_cpu(unsigned int cpuid) { struct cpuinfo_x86 *cpu = &cpu_data(cpuid); @@ -887,6 +907,7 @@ static int acpi_cpufreq_resume(struct cpufreq_policy *policy) static struct freq_attr *acpi_cpufreq_attr[] = { &cpufreq_freq_attr_scaling_available_freqs, + NULL, /* this is a placeholder for cpb, do not remove */ NULL, }; @@ -958,6 +979,27 @@ static int __init acpi_cpufreq_init(void) if (ret) return ret; +#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB + /* this is a sysfs file with a strange name and an even stranger + * semantic - per CPU instantiation, but system global effect. + * Lets enable it only on AMD CPUs for compatibility reasons and + * only if configured. This is considered legacy code, which + * will probably be removed at some point in the future. + */ + if (check_amd_hwpstate_cpu(0)) { + struct freq_attr **iter; + + pr_debug("adding sysfs entry for cpb\n"); + + for (iter = acpi_cpufreq_attr; *iter != NULL; iter++) + ; + + /* make sure there is a terminator behind it */ + if (iter[1] == NULL) + *iter = &cpb; + } +#endif + ret = cpufreq_register_driver(&acpi_cpufreq_driver); if (ret) free_acpi_perf_data();
The powernow-k8 driver supported a sysfs knob called "cpb", which was instantiated per CPU, but actually acted globally for the whole system. To keep some compatibility with this feature, we re-introduce this behavior here, but: a) only enable it on AMD CPUs and b) protect it with a Kconfig switch I'd like to consider this feature obsolete. Lets keep it around for some kernel versions and then phase it out. Signed-off-by: Andre Przywara <andre.przywara@amd.com> --- drivers/cpufreq/Kconfig.x86 | 12 ++++++++++ drivers/cpufreq/acpi-cpufreq.c | 46 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 56 insertions(+), 2 deletions(-)