/*
* 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>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*/
#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <acpi/processor.h>
#include <asm/cpu.h>
#include "internal.h"
#define _COMPONENT ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor");
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);
static int acpi_processor_errata_piix4(struct pci_dev *dev)
{
u8 value1 = 0;
u8 value2 = 0;
if (!dev)
return -EINVAL;
/*
* Note that 'dev' references the PIIX4 ACPI Controller.
*/
switch (dev->revision) {
case 0:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
break;
case 1:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
break;
case 2:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
break;
case 3:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
break;
default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "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.piix4.throttle = 1;
case 2: /* PIIX4E */
case 3: /* PIIX4M */
/*
* See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
* Livelock") from the January 2002 PIIX4 specification update.
* Applies to all PIIX4 models.
*/
/*
* BM-IDE
* ------
* Find the PIIX4 IDE Controller and get the Bus Master IDE
* Status register address. We'll use this later to read
* each IDE controller's DMA status to make sure we catch all
* DMA activity.
*/
dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
PCI_DEVICE_ID_INTEL_82371AB,
PCI_ANY_ID, PCI_ANY_ID, NULL);
if (dev) {
errata.piix4.bmisx = pci_resource_start(dev, 4);
pci_dev_put(dev);
}
/*
* Type-F DMA
* ----------
* Find the PIIX4 ISA Controller and read the Motherboard
* DMA controller's status to see if Type-F (Fast) DMA mode
* is enabled (bit 7) on either channel. Note that we'll
* disable C3 support if this is enabled, as some legacy
* devices won't operate well if fast DMA is disabled.
*/
dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
PCI_DEVICE_ID_INTEL_82371AB_0,
PCI_ANY_ID, PCI_ANY_ID, NULL);
if (dev) {
pci_read_config_byte(dev, 0x76, &value1);
pci_read_config_byte(dev, 0x77, &value2);
if ((value1 & 0x80) || (value2 & 0x80))
errata.piix4.fdma = 1;
pci_dev_put(dev);
}
break;
}
if (errata.piix4.bmisx)
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Bus master activity detection (BM-IDE) erratum enabled\n"));
if (errata.piix4.fdma)
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Type-F DMA livelock erratum (C3 disabled)\n"));
return 0;
}
static int acpi_processor_errata(struct acpi_processor *pr)
{
int result = 0;
struct pci_dev *dev = NULL;
if (!pr)
return -EINVAL;
/*
* PIIX4
*/
dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
PCI_ANY_ID, NULL);
if (dev) {
result = acpi_processor_errata_piix4(dev);
pci_dev_put(dev);
}
return result;
}
/* --------------------------------------------------------------------------
Initialization
-------------------------------------------------------------------------- */
#ifdef CONFIG_ACPI_HOTPLUG_CPU
static int acpi_processor_hotadd_init(struct acpi_processor *pr)
{
unsigned long long sta;
acpi_status status;
int ret;
status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
return -ENODEV;
cpu_maps_update_begin();
cpu_hotplug_begin();
ret = acpi_map_lsapic(pr->handle, &pr->id);
if (ret)
goto out;
ret = arch_register_cpu(pr->id);
if (ret) {
acpi_unmap_lsapic(pr->id);
goto out;
}
/*
* CPU got hot-added, but cpu_data is not initialized yet. Set a flag
* to delay cpu_idle/throttling initialization and do it when the CPU
* gets online for the first time.
*/
pr_info("CPU%d has been hot-added\n", pr->id);
pr->flags.need_hotplug_init = 1;
out:
cpu_hotplug_done();
cpu_maps_update_done();
return ret;
}
#else
static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
{
return -ENODEV;
}
#endif /* CONFIG_ACPI_HOTPLUG_CPU */
static int acpi_processor_get_info(struct acpi_device *device)
{
union acpi_object object = { 0 };
struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
struct acpi_processor *pr = acpi_driver_data(device);
int cpu_index, device_declaration = 0;
acpi_status status = AE_OK;
static int cpu0_initialized;
if (num_online_cpus() > 1)
errata.smp = TRUE;
acpi_processor_errata(pr);
/*
* Check to see if we have bus mastering arbitration control. This
* is required for proper C3 usage (to maintain cache coherency).
*/
if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
pr->flags.bm_control = 1;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Bus mastering arbitration control present\n"));
} else
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"No bus mastering arbitration control\n"));
if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
/* Declared with "Processor" statement; match ProcessorID */
status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
if (ACPI_FAILURE(status)) {
dev_err(&device->dev,
"Failed to evaluate processor object (0x%x)\n",
status);
return -ENODEV;
}
/*
* TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
* >>> 'acpi_get_processor_id(acpi_id, &id)' in
* arch/xxx/acpi.c
*/
pr->acpi_id = object.processor.proc_id;
} else {
/*
* Declared with "Device" statement; match _UID.
* Note that we don't handle string _UIDs yet.
*/
unsigned long long value;
status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
NULL, &value);
if (ACPI_FAILURE(status)) {
dev_err(&device->dev,
"Failed to evaluate processor _UID (0x%x)\n",
status);
return -ENODEV;
}
device_declaration = 1;
pr->acpi_id = value;
}
pr->apic_id = acpi_get_apicid(pr->handle, device_declaration,
pr->acpi_id);
cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id);
/* Handle UP system running SMP kernel, with no LAPIC in MADT */
if (!cpu0_initialized && (cpu_index == -1) &&
(num_online_cpus() == 1)) {
cpu_index = 0;
}
cpu0_initialized = 1;
pr->id = cpu_index;
/*
* Extra Processor objects may be enumerated on MP systems with
* less than the max # of CPUs. They should be ignored _iff
* they are physically not present.
*/
if (pr->id == -1) {
int ret = acpi_processor_hotadd_init(pr);
if (ret)
return ret;
}
/*
* On some boxes several processors use the same processor bus id.
* But they are located in different scope. For example:
* \_SB.SCK0.CPU0
* \_SB.SCK1.CPU0
* Rename the processor device bus id. And the new bus id will be
* generated as the following format:
* CPU+CPU ID.
*/
sprintf(acpi_device_bid(device), "CPU%X", pr->id);
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
pr->acpi_id));
if (!object.processor.pblk_address)
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
else if (object.processor.pblk_length != 6)
dev_err(&device->dev, "Invalid PBLK length [%d]\n",
object.processor.pblk_length);
else {
pr->throttling.address = object.processor.pblk_address;
pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
pr->pblk = object.processor.pblk_address;
/*
* We don't care about error returns - we just try to mark
* these reserved so that nobody else is confused into thinking
* that this region might be unused..
*
* (In particular, allocating the IO range for Cardbus)
*/
request_region(pr->throttling.address, 6, "ACPI CPU throttle");
}
/*
* If ACPI describes a slot number for this CPU, we can use it to
* ensure we get the right value in the "physical id" field
* of /proc/cpuinfo
*/
status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
if (ACPI_SUCCESS(status))
arch_fix_phys_package_id(pr->id, object.integer.value);
return 0;
}
/*
* Do not put anything in here which needs the core to be online.
* For example MSR access or setting up things which check for cpuinfo_x86
* (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
* Such things have to be put in and set up by the processor driver's .probe().
*/
static DEFINE_PER_CPU(void *, processor_device_array);
static int acpi_processor_add(struct acpi_device *device,
const struct acpi_device_id *id)
{
struct acpi_processor *pr;
struct device *dev;
int result = 0;
pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
if (!pr)
return -ENOMEM;
if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
result = -ENOMEM;
goto err_free_pr;
}
pr->handle = device->handle;
strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
device->driver_data = pr;
result = acpi_processor_get_info(device);
if (result) /* Processor is not physically present or unavailable */
return 0;
#ifdef CONFIG_SMP
if (pr->id >= setup_max_cpus && pr->id != 0)
return 0;
#endif
BUG_ON(pr->id >= nr_cpu_ids);
/*
* Buggy BIOS check.
* ACPI id of processors can be reported wrongly by the BIOS.
* Don't trust it blindly
*/
if (per_cpu(processor_device_array, pr->id) != NULL &&
per_cpu(processor_device_array, pr->id) != device) {
dev_warn(&device->dev,
"BIOS reported wrong ACPI id %d for the processor\n",
pr->id);
/* Give up, but do not abort the namespace scan. */
goto err;
}
/*
* processor_device_array is not cleared on errors to allow buggy BIOS
* checks.
*/
per_cpu(processor_device_array, pr->id) = device;
per_cpu(processors, pr->id) = pr;
dev = get_cpu_device(pr->id);
if (!dev) {
result = -ENODEV;
goto err;
}
result = acpi_bind_one(dev, pr->handle);
if (result)
goto err;
pr->dev = dev;
dev->offline = pr->flags.need_hotplug_init;
/* Trigger the processor driver's .probe() if present. */
if (device_attach(dev) >= 0)
return 1;
dev_err(dev, "Processor driver could not be attached\n");
acpi_unbind_one(dev);
err:
free_cpumask_var(pr->throttling.shared_cpu_map);
device->driver_data = NULL;
per_cpu(processors, pr->id) = NULL;
err_free_pr:
kfree(pr);
return result;
}
#ifdef CONFIG_ACPI_HOTPLUG_CPU
/* --------------------------------------------------------------------------
Removal
-------------------------------------------------------------------------- */
static void acpi_processor_remove(struct acpi_device *device)
{
struct acpi_processor *pr;
if (!device || !acpi_driver_data(device))
return;
pr = acpi_driver_data(device);
if (pr->id >= nr_cpu_ids)
goto out;
/*
* The only reason why we ever get here is CPU hot-removal. The CPU is
* already offline and the ACPI device removal locking prevents it from
* being put back online at this point.
*
* Unbind the driver from the processor device and detach it from the
* ACPI companion object.
*/
device_release_driver(pr->dev);
acpi_unbind_one(pr->dev);
/* Clean up. */
per_cpu(processor_device_array, pr->id) = NULL;
per_cpu(processors, pr->id) = NULL;
cpu_maps_update_begin();
cpu_hotplug_begin();
/* Remove the CPU. */
arch_unregister_cpu(pr->id);
acpi_unmap_lsapic(pr->id);
cpu_hotplug_done();
cpu_maps_update_done();
try_offline_node(cpu_to_node(pr->id));
out:
free_cpumask_var(pr->throttling.shared_cpu_map);
kfree(pr);
}
#endif /* CONFIG_ACPI_HOTPLUG_CPU */
/*
* The following ACPI IDs are known to be suitable for representing as
* processor devices.
*/
static const struct acpi_device_id processor_device_ids[] = {
{ ACPI_PROCESSOR_OBJECT_HID, },
{ ACPI_PROCESSOR_DEVICE_HID, },
{ }
};
static struct acpi_scan_handler __refdata processor_handler = {
.ids = processor_device_ids,
.attach = acpi_processor_add,
#ifdef CONFIG_ACPI_HOTPLUG_CPU
.detach = acpi_processor_remove,
#endif
.hotplug = {
.enabled = true,
},
};
void __init acpi_processor_init(void)
{
acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
}
