// SPDX-License-Identifier: GPL-2.0-only
/*
* acpi_processor.c - ACPI processor enumeration support
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
* Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
* Copyright (C) 2013, Intel Corporation
* Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*/
#define pr_fmt(fmt) "ACPI: " fmt
#include <linux/acpi.h>
#include <linux/cpu.h>
#include <linux/device.h>
#include <linux/dmi.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <acpi/processor.h>
#include <asm/cpu.h>
#include <xen/xen.h>
#include "internal.h"
DEFINE_PER_CPU(struct acpi_processor *, processors);
EXPORT_PER_CPU_SYMBOL(processors);
/* Errata Handling */
struct acpi_processor_errata errata __read_mostly;
EXPORT_SYMBOL_GPL(errata);
acpi_handle acpi_get_processor_handle(int cpu)
{
struct acpi_processor *pr;
pr = per_cpu(processors, cpu);
if (pr)
return pr->handle;
return NULL;
}
static int acpi_processor_errata_piix4(struct pci_dev *dev)
{
if (!dev)
return -EINVAL;
/*
* Note that 'dev' references the PIIX4 ACPI Controller.
*/
switch (dev->revision) {
case 0:
dev_dbg(&dev->dev, "Found PIIX4 A-step\n");
break;
case 1:
dev_dbg(&dev->dev, "Found PIIX4 B-step\n");
break;
case 2:
dev_dbg(&dev->dev, "Found PIIX4E\n");
break;
case 3:
dev_dbg(&dev->dev, "Found PIIX4M\n");
break;
default:
dev_dbg(&dev->dev, "Found unknown PIIX4\n");
break;
}
switch (dev->revision) {
case 0: /* PIIX4 A-step */
case 1: /* PIIX4 B-step */
/*
* See specification changes #13 ("Manual Throttle Duty Cycle")
* and #14 ("Enabling and Disabling Manual Throttle"), plus
* erratum #5 ("STPCLK# Deassertion Time") from the January
* 2002 PIIX4 specification update. Applies to only older
* PIIX4 models.
*/
errata.</