Commit 35ae7133 authored by Sudeep Holla's avatar Sudeep Holla Committed by Rafael J. Wysocki
Browse files

ACPI / processor_idle: introduce ACPI_PROCESSOR_CSTATE 



ACPI 6.0 adds a new method to specify the CPU idle states(C-states)
called Low Power Idle(LPI) states. Since new architectures like ARM64
use only LPIs, introduce ACPI_PROCESSOR_CSTATE to encapsulate all the
code supporting the old style C-states(_CST).

This patch will help to extend the processor_idle module to support
LPI.

Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 92d21ac7

drivers/acpi/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -213,6 +213,10 @@ config ACPI_CPU_FREQ_PSS 
	bool

	select THERMAL



config ACPI_PROCESSOR_CSTATE

	def_bool y

	depends on IA64 || X86



config ACPI_PROCESSOR_IDLE

	bool

	select CPU_IDLE

drivers/acpi/processor_idle.c

+53 −27
Original line number Diff line number Diff line
@@ -59,6 +59,12 @@ module_param(latency_factor, uint, 0644); 


static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);



struct cpuidle_driver acpi_idle_driver = {

	.name =		"acpi_idle",

	.owner =	THIS_MODULE,

};



#ifdef CONFIG_ACPI_PROCESSOR_CSTATE

static

DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
@@ -804,11 +810,6 @@ static void acpi_idle_enter_freeze(struct cpuidle_device *dev, 
	acpi_idle_do_entry(cx);

}



struct cpuidle_driver acpi_idle_driver = {

	.name =		"acpi_idle",

	.owner =	THIS_MODULE,

};



/**

 * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE

 * device i.e. per-cpu data
@@ -925,6 +926,50 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) 
	return 0;

}



static inline void acpi_processor_cstate_first_run_checks(void)

{

	acpi_status status;

	static int first_run;



	if (first_run)

		return;

	dmi_check_system(processor_power_dmi_table);

	max_cstate = acpi_processor_cstate_check(max_cstate);

	if (max_cstate < ACPI_C_STATES_MAX)

		pr_notice("ACPI: processor limited to max C-state %d\n",

			  max_cstate);

	first_run++;



	if (acpi_gbl_FADT.cst_control && !nocst) {

		status = acpi_os_write_port(acpi_gbl_FADT.smi_command,

					    acpi_gbl_FADT.cst_control, 8);

		if (ACPI_FAILURE(status))

			ACPI_EXCEPTION((AE_INFO, status,

					"Notifying BIOS of _CST ability failed"));

	}

}

#else



static inline int disabled_by_idle_boot_param(void) { return 0; }

static inline void acpi_processor_cstate_first_run_checks(void) { }

static int acpi_processor_get_power_info(struct acpi_processor *pr)

{

	return -ENODEV;

}



static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,

					   struct cpuidle_device *dev)

{

	return -EINVAL;

}



static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)

{

	return -EINVAL;

}



#endif /* CONFIG_ACPI_PROCESSOR_CSTATE */



int acpi_processor_hotplug(struct acpi_processor *pr)

{

	int ret = 0;
@@ -1015,34 +1060,15 @@ static int acpi_processor_registered; 


int acpi_processor_power_init(struct acpi_processor *pr)

{

	acpi_status status;

	int retval;

	struct cpuidle_device *dev;

	static int first_run;



	if (disabled_by_idle_boot_param())

		return 0;



	if (!first_run) {

		dmi_check_system(processor_power_dmi_table);

		max_cstate = acpi_processor_cstate_check(max_cstate);

		if (max_cstate < ACPI_C_STATES_MAX)

			printk(KERN_NOTICE

			       "ACPI: processor limited to max C-state %d\n",

			       max_cstate);

		first_run++;

	}

	acpi_processor_cstate_first_run_checks();



	if (acpi_gbl_FADT.cst_control && !nocst) {

		status =

		    acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);

		if (ACPI_FAILURE(status)) {

			ACPI_EXCEPTION((AE_INFO, status,

					"Notifying BIOS of _CST ability failed"));

		}

	}



	acpi_processor_get_power_info(pr);

	if (!acpi_processor_get_power_info(pr))

		pr->flags.power_setup_done = 1;



	/*

include/acpi/processor.h

+1 −1
Original line number Diff line number Diff line
@@ -242,7 +242,7 @@ extern int acpi_processor_get_performance_info(struct acpi_processor *pr); 
DECLARE_PER_CPU(struct acpi_processor *, processors);

extern struct acpi_processor_errata errata;



#ifdef ARCH_HAS_POWER_INIT

#if defined(ARCH_HAS_POWER_INIT) && defined(CONFIG_ACPI_PROCESSOR_CSTATE)

void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,

					unsigned int cpu);

int acpi_processor_ffh_cstate_probe(unsigned int cpu,

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