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Commit 5d554a7b authored by Alex Chiang's avatar Alex Chiang Committed by Len Brown
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ACPI: processor: add internal processor_physically_present() 



Detect if a processor is physically present before evaluating _PDC.

We want this because some BIOS will provide a _PDC even for processors
that are not present. These bogus _PDC methods then attempt to load
non-existent tables, which causes problems.

Avoid those bogus landmines.

Acked-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: default avatarAlex Chiang <achiang@hp.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 78ed8bd2

drivers/acpi/processor_core.c

+42 −0
Original line number Diff line number Diff line
@@ -194,6 +194,45 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id) 
EXPORT_SYMBOL_GPL(acpi_get_cpuid);

#endif



static bool processor_physically_present(acpi_handle handle)

{

	int cpuid, type;

	u32 acpi_id;

	acpi_status status;

	acpi_object_type acpi_type;

	unsigned long long tmp;

	union acpi_object object = { 0 };

	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };



	status = acpi_get_type(handle, &acpi_type);

	if (ACPI_FAILURE(status))

		return false;



	switch (acpi_type) {

	case ACPI_TYPE_PROCESSOR:

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

		if (ACPI_FAILURE(status))

			return false;

		acpi_id = object.processor.proc_id;

		break;

	case ACPI_TYPE_DEVICE:

		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);

		if (ACPI_FAILURE(status))

			return false;

		acpi_id = tmp;

		break;

	default:

		return false;

	}



	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;

	cpuid = acpi_get_cpuid(handle, type, acpi_id);



	if (cpuid == -1)

		return false;



	return true;

}



static void acpi_set_pdc_bits(u32 *buf)

{
@@ -335,6 +374,9 @@ static struct dmi_system_id __cpuinitdata early_pdc_optin_table[] = { 
static acpi_status

early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)

{

	if (processor_physically_present(handle) == false)

		return AE_OK;



	acpi_processor_set_pdc(handle);

	return AE_OK;

}