Commit 77fb4e0a authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPI: processor: Export acpi_processor_evaluate_cst() 



The intel_idle driver will be modified to use ACPI _CST subsequently
and it will need to call acpi_processor_evaluate_cst(), so move that
function to acpi_processor.c so that it is always present (which is
required by intel_idle) and export it to modules to allow the ACPI
processor driver (which is modular) to call it.

No intentional functional impact.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 239ed06d

drivers/acpi/acpi_processor.c

+157 −0
Original line number Diff line number Diff line
@@ -729,4 +729,161 @@ bool acpi_processor_claim_cst_control(void) 
	return true;

}

EXPORT_SYMBOL_GPL(acpi_processor_claim_cst_control);



/**

 * acpi_processor_evaluate_cst - Evaluate the processor _CST control method.

 * @handle: ACPI handle of the processor object containing the _CST.

 * @cpu: The numeric ID of the target CPU.

 * @info: Object write the C-states information into.

 *

 * Extract the C-state information for the given CPU from the output of the _CST

 * control method under the corresponding ACPI processor object (or processor

 * device object) and populate @info with it.

 *

 * If any ACPI_ADR_SPACE_FIXED_HARDWARE C-states are found, invoke

 * acpi_processor_ffh_cstate_probe() to verify them and update the

 * cpu_cstate_entry data for @cpu.

 */

int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,

				struct acpi_processor_power *info)

{

	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	union acpi_object *cst;

	acpi_status status;

	u64 count;

	int last_index = 0;

	int i, ret = 0;



	status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);

	if (ACPI_FAILURE(status)) {

		acpi_handle_debug(handle, "No _CST\n");

		return -ENODEV;

	}



	cst = buffer.pointer;



	/* There must be at least 2 elements. */

	if (!cst || cst->type != ACPI_TYPE_PACKAGE || cst->package.count < 2) {

		acpi_handle_warn(handle, "Invalid _CST output\n");

		ret = -EFAULT;

		goto end;

	}



	count = cst->package.elements[0].integer.value;



	/* Validate the number of C-states. */

	if (count < 1 || count != cst->package.count - 1) {

		acpi_handle_warn(handle, "Inconsistent _CST data\n");

		ret = -EFAULT;

		goto end;

	}



	for (i = 1; i <= count; i++) {

		union acpi_object *element;

		union acpi_object *obj;

		struct acpi_power_register *reg;

		struct acpi_processor_cx cx;



		/*

		 * If there is not enough space for all C-states, skip the

		 * excess ones and log a warning.

		 */

		if (last_index >= ACPI_PROCESSOR_MAX_POWER - 1) {

			acpi_handle_warn(handle,

					 "No room for more idle states (limit: %d)\n",

					 ACPI_PROCESSOR_MAX_POWER - 1);

			break;

		}



		memset(&cx, 0, sizeof(cx));



		element = &cst->package.elements[i];

		if (element->type != ACPI_TYPE_PACKAGE)

			continue;



		if (element->package.count != 4)

			continue;



		obj = &element->package.elements[0];



		if (obj->type != ACPI_TYPE_BUFFER)

			continue;



		reg = (struct acpi_power_register *)obj->buffer.pointer;



		obj = &element->package.elements[1];

		if (obj->type != ACPI_TYPE_INTEGER)

			continue;



		cx.type = obj->integer.value;

		/*

		 * There are known cases in which the _CST output does not

		 * contain C1, so if the type of the first state found is not

		 * C1, leave an empty slot for C1 to be filled in later.

		 */

		if (i == 1 && cx.type != ACPI_STATE_C1)

			last_index = 1;



		cx.address = reg->address;

		cx.index = last_index + 1;



		if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {

			if (!acpi_processor_ffh_cstate_probe(cpu, &cx, reg)) {

				/*

				 * In the majority of cases _CST describes C1 as

				 * a FIXED_HARDWARE C-state, but if the command

				 * line forbids using MWAIT, use CSTATE_HALT for

				 * C1 regardless.

				 */

				if (cx.type == ACPI_STATE_C1 &&

				    boot_option_idle_override == IDLE_NOMWAIT) {

					cx.entry_method = ACPI_CSTATE_HALT;

					snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");

				} else {

					cx.entry_method = ACPI_CSTATE_FFH;

				}

			} else if (cx.type == ACPI_STATE_C1) {

				/*

				 * In the special case of C1, FIXED_HARDWARE can

				 * be handled by executing the HLT instruction.

				 */

				cx.entry_method = ACPI_CSTATE_HALT;

				snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");

			} else {

				continue;

			}

		} else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {

			cx.entry_method = ACPI_CSTATE_SYSTEMIO;

			snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",

				 cx.address);

		} else {

			continue;

		}



		if (cx.type == ACPI_STATE_C1)

			cx.valid = 1;



		obj = &element->package.elements[2];

		if (obj->type != ACPI_TYPE_INTEGER)

			continue;



		cx.latency = obj->integer.value;



		obj = &element->package.elements[3];

		if (obj->type != ACPI_TYPE_INTEGER)

			continue;



		memcpy(&info->states[++last_index], &cx, sizeof(cx));

	}



	acpi_handle_info(handle, "Found %d idle states\n", last_index);



	info->count = last_index;



      end:

	kfree(buffer.pointer);



	return ret;

}

EXPORT_SYMBOL_GPL(acpi_processor_evaluate_cst);

#endif /* CONFIG_ACPI_PROCESSOR_CSTATE */

drivers/acpi/processor_idle.c

+0 −142
Original line number Diff line number Diff line
@@ -297,148 +297,6 @@ static int acpi_processor_get_power_info_default(struct acpi_processor *pr) 
	return 0;

}



static int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,

				       struct acpi_processor_power *info)

{

	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	union acpi_object *cst;

	acpi_status status;

	u64 count;

	int last_index = 0;

	int i, ret = 0;



	status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);

	if (ACPI_FAILURE(status)) {

		acpi_handle_debug(handle, "No _CST\n");

		return -ENODEV;

	}



	cst = buffer.pointer;



	/* There must be at least 2 elements. */

	if (!cst || cst->type != ACPI_TYPE_PACKAGE || cst->package.count < 2) {

		acpi_handle_warn(handle, "Invalid _CST output\n");

		ret = -EFAULT;

		goto end;

	}



	count = cst->package.elements[0].integer.value;



	/* Validate the number of C-states. */

	if (count < 1 || count != cst->package.count - 1) {

		acpi_handle_warn(handle, "Inconsistent _CST data\n");

		ret = -EFAULT;

		goto end;

	}



	for (i = 1; i <= count; i++) {

		union acpi_object *element;

		union acpi_object *obj;

		struct acpi_power_register *reg;

		struct acpi_processor_cx cx;



		/*

		 * If there is not enough space for all C-states, skip the

		 * excess ones and log a warning.

		 */

		if (last_index >= ACPI_PROCESSOR_MAX_POWER - 1) {

			acpi_handle_warn(handle,

					 "No room for more idle states (limit: %d)\n",

					 ACPI_PROCESSOR_MAX_POWER - 1);

			break;

		}



		memset(&cx, 0, sizeof(cx));



		element = &cst->package.elements[i];

		if (element->type != ACPI_TYPE_PACKAGE)

			continue;



		if (element->package.count != 4)

			continue;



		obj = &element->package.elements[0];



		if (obj->type != ACPI_TYPE_BUFFER)

			continue;



		reg = (struct acpi_power_register *)obj->buffer.pointer;



		obj = &element->package.elements[1];

		if (obj->type != ACPI_TYPE_INTEGER)

			continue;



		cx.type = obj->integer.value;

		/*

		 * There are known cases in which the _CST output does not

		 * contain C1, so if the type of the first state found is not

		 * C1, leave an empty slot for C1 to be filled in later.

		 */

		if (i == 1 && cx.type != ACPI_STATE_C1)

			last_index = 1;



		cx.address = reg->address;

		cx.index = last_index + 1;



		if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {

			if (!acpi_processor_ffh_cstate_probe(cpu, &cx, reg)) {

				/*

				 * In the majority of cases _CST describes C1 as

				 * a FIXED_HARDWARE C-state, but if the command

				 * line forbids using MWAIT, use CSTATE_HALT for

				 * C1 regardless.

				 */

				if (cx.type == ACPI_STATE_C1 &&

				    boot_option_idle_override == IDLE_NOMWAIT) {

					cx.entry_method = ACPI_CSTATE_HALT;

					snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");

				} else {

					cx.entry_method = ACPI_CSTATE_FFH;

				}

			} else if (cx.type == ACPI_STATE_C1) {

				/*

				 * In the special case of C1, FIXED_HARDWARE can

				 * be handled by executing the HLT instruction.

				 */

				cx.entry_method = ACPI_CSTATE_HALT;

				snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");

			} else {

				continue;

			}

		} else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {

			cx.entry_method = ACPI_CSTATE_SYSTEMIO;

			snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",

				 cx.address);

		} else {

			continue;

		}



		if (cx.type == ACPI_STATE_C1)

			cx.valid = 1;



		obj = &element->package.elements[2];

		if (obj->type != ACPI_TYPE_INTEGER)

			continue;



		cx.latency = obj->integer.value;



		obj = &element->package.elements[3];

		if (obj->type != ACPI_TYPE_INTEGER)

			continue;



		memcpy(&info->states[++last_index], &cx, sizeof(cx));

	}



	acpi_handle_info(handle, "Found %d idle states\n", last_index);



	info->count = last_index;



      end:

	kfree(buffer.pointer);



	return ret;

}



static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)

{

	int ret;

include/linux/acpi.h

+9 −0
Original line number Diff line number Diff line
@@ -280,10 +280,19 @@ static inline bool invalid_phys_cpuid(phys_cpuid_t phys_id) 
/* Validate the processor object's proc_id */

bool acpi_duplicate_processor_id(int proc_id);

/* Processor _CTS control */

struct acpi_processor_power;



#ifdef CONFIG_ACPI_PROCESSOR_CSTATE

bool acpi_processor_claim_cst_control(void);

int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,

				struct acpi_processor_power *info);

#else

static inline bool acpi_processor_claim_cst_control(void) { return false; }

static inline int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,

					      struct acpi_processor_power *info)

{

	return -ENODEV;

}

#endif



#ifdef CONFIG_ACPI_HOTPLUG_CPU

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