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Commit ecf5636d authored by Yinghai Lu's avatar Yinghai Lu Committed by Rafael J. Wysocki
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ACPI: Add interfaces to parse IOAPIC ID for IOAPIC hotplug 



We need to parse APIC ID for IOAPIC registration for IOAPIC hotplug.
ACPI _MAT method and MADT table are used to figure out IOAPIC ID, just
like parsing CPU APIC ID for CPU hotplug.

[ tglx: Fixed docbook comment ]

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarJiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/1414387308-27148-8-git-send-email-jiang.liu@linux.intel.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent b4b55cda

drivers/acpi/processor_core.c

+114 −9
Original line number Diff line number Diff line
@@ -4,6 +4,10 @@ 
 *

 *	Alex Chiang <achiang@hp.com>

 *	- Unified x86/ia64 implementations

 *

 * I/O APIC hotplug support

 *	Yinghai Lu <yinghai@kernel.org>

 *	Jiang Liu <jiang.liu@intel.com>

 */

#include <linux/export.h>

#include <linux/acpi.h>
@@ -12,6 +16,21 @@ 
#define _COMPONENT		ACPI_PROCESSOR_COMPONENT

ACPI_MODULE_NAME("processor_core");



static struct acpi_table_madt *get_madt_table(void)

{

	static struct acpi_table_madt *madt;

	static int read_madt;



	if (!read_madt) {

		if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,

					(struct acpi_table_header **)&madt)))

			madt = NULL;

		read_madt++;

	}



	return madt;

}



static int map_lapic_id(struct acpi_subtable_header *entry,

		 u32 acpi_id, int *apic_id)

{
@@ -67,17 +86,10 @@ static int map_lsapic_id(struct acpi_subtable_header *entry, 
static int map_madt_entry(int type, u32 acpi_id)

{

	unsigned long madt_end, entry;

	static struct acpi_table_madt *madt;

	static int read_madt;

	int phys_id = -1;	/* CPU hardware ID */

	struct acpi_table_madt *madt;



	if (!read_madt) {

		if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,

					(struct acpi_table_header **)&madt)))

			madt = NULL;

		read_madt++;

	}



	madt = get_madt_table();

	if (!madt)

		return phys_id;
@@ -203,3 +215,96 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id) 
	return acpi_map_cpuid(phys_id, acpi_id);

}

EXPORT_SYMBOL_GPL(acpi_get_cpuid);



#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC

static int get_ioapic_id(struct acpi_subtable_header *entry, u32 gsi_base,

			 u64 *phys_addr, int *ioapic_id)

{

	struct acpi_madt_io_apic *ioapic = (struct acpi_madt_io_apic *)entry;



	if (ioapic->global_irq_base != gsi_base)

		return 0;



	*phys_addr = ioapic->address;

	*ioapic_id = ioapic->id;

	return 1;

}



static int parse_madt_ioapic_entry(u32 gsi_base, u64 *phys_addr)

{

	struct acpi_subtable_header *hdr;

	unsigned long madt_end, entry;

	struct acpi_table_madt *madt;

	int apic_id = -1;



	madt = get_madt_table();

	if (!madt)

		return apic_id;



	entry = (unsigned long)madt;

	madt_end = entry + madt->header.length;



	/* Parse all entries looking for a match. */

	entry += sizeof(struct acpi_table_madt);

	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {

		hdr = (struct acpi_subtable_header *)entry;

		if (hdr->type == ACPI_MADT_TYPE_IO_APIC &&

		    get_ioapic_id(hdr, gsi_base, phys_addr, &apic_id))

			break;

		else

			entry += hdr->length;

	}



	return apic_id;

}



static int parse_mat_ioapic_entry(acpi_handle handle, u32 gsi_base,

				  u64 *phys_addr)

{

	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	struct acpi_subtable_header *header;

	union acpi_object *obj;

	int apic_id = -1;



	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))

		goto exit;



	if (!buffer.length || !buffer.pointer)

		goto exit;



	obj = buffer.pointer;

	if (obj->type != ACPI_TYPE_BUFFER ||

	    obj->buffer.length < sizeof(struct acpi_subtable_header))

		goto exit;



	header = (struct acpi_subtable_header *)obj->buffer.pointer;

	if (header->type == ACPI_MADT_TYPE_IO_APIC)

		get_ioapic_id(header, gsi_base, phys_addr, &apic_id);



exit:

	kfree(buffer.pointer);

	return apic_id;

}



/**

 * acpi_get_ioapic_id - Get IOAPIC ID and physical address matching @gsi_base

 * @handle:	ACPI object for IOAPIC device

 * @gsi_base:	GSI base to match with

 * @phys_addr:	Pointer to store physical address of matching IOAPIC record

 *

 * Walk resources returned by ACPI_MAT method, then ACPI MADT table, to search

 * for an ACPI IOAPIC record matching @gsi_base.

 * Return IOAPIC id and store physical address in @phys_addr if found a match,

 * otherwise return <0.

 */

int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr)

{

	int apic_id;



	apic_id = parse_mat_ioapic_entry(handle, gsi_base, phys_addr);

	if (apic_id == -1)

		apic_id = parse_madt_ioapic_entry(gsi_base, phys_addr);



	return apic_id;

}

#endif /* CONFIG_ACPI_HOTPLUG_IOAPIC */

include/linux/acpi.h

+4 −0
Original line number Diff line number Diff line
@@ -152,6 +152,10 @@ int acpi_map_cpu(acpi_handle handle, int physid, int *pcpu); 
int acpi_unmap_cpu(int cpu);

#endif /* CONFIG_ACPI_HOTPLUG_CPU */



#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC

int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr);

#endif



int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base);

int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base);

int acpi_ioapic_registered(acpi_handle handle, u32 gsi_base);