acpi-cpufreq: Add compatibility for legacy AMD cpb sysfs knob (11269ff5) · Commits · 戴 / test

drivers/cpufreq/Kconfig.x86

+12 −0

Original line number	Diff line number	Diff line
		@@ -33,6 +33,18 @@ 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

drivers/cpufreq/acpi-cpufreq.c

+44 −2

Original line number	Diff line number	Diff line
		@@ -133,8 +133,7 @@ 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;
		@@ -161,6 +160,12 @@ 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)
		{
		@@ -171,6 +176,21 @@ 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);
		@@ -889,6 +909,7 @@ 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,
		};

		@@ -960,6 +981,27 @@ 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();

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