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linux/drivers/acpi/processor_driver.c

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/*
* acpi_processor.c - ACPI Processor Driver ($Revision: 71 $)
*
* 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>
* - Added processor hotplug support
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* TBD:
* 1. Make # power states dynamic.
* 2. Support duty_cycle values that span bit 4.
* 3. Optimize by having scheduler determine business instead of
* having us try to calculate it here.
* 4. Need C1 timing -- must modify kernel (IRQ handler) to get this.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/pm.h>
#include <linux/cpufreq.h>
#include <linux/cpu.h>
#include <linux/dmi.h>
#include <linux/moduleparam.h>
#include <linux/cpuidle.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <asm/io.h>
#include <asm/cpu.h>
#include <asm/delay.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <asm/smp.h>
#include <asm/acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include <acpi/processor.h>
#define PREFIX "ACPI: "
#define ACPI_PROCESSOR_CLASS "processor"
#define ACPI_PROCESSOR_DEVICE_NAME "Processor"
#define ACPI_PROCESSOR_FILE_INFO "info"
#define ACPI_PROCESSOR_FILE_THROTTLING "throttling"
#define ACPI_PROCESSOR_FILE_LIMIT "limit"
#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
#define ACPI_PROCESSOR_NOTIFY_POWER 0x81
#define ACPI_PROCESSOR_NOTIFY_THROTTLING 0x82
#define ACPI_PROCESSOR_DEVICE_HID "ACPI0007"
#define ACPI_PROCESSOR_LIMIT_USER 0
#define ACPI_PROCESSOR_LIMIT_THERMAL 1
#define _COMPONENT ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_driver");
MODULE_AUTHOR("Paul Diefenbaugh");
MODULE_DESCRIPTION("ACPI Processor Driver");
MODULE_LICENSE("GPL");
static int acpi_processor_add(struct acpi_device *device);
static int acpi_processor_remove(struct acpi_device *device, int type);
static void acpi_processor_notify(struct acpi_device *device, u32 event);
static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr);
static int acpi_processor_handle_eject(struct acpi_processor *pr);
static int acpi_processor_start(struct acpi_processor *pr);
static const struct acpi_device_id processor_device_ids[] = {
{ACPI_PROCESSOR_OBJECT_HID, 0},
{ACPI_PROCESSOR_DEVICE_HID, 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, processor_device_ids);
static SIMPLE_DEV_PM_OPS(acpi_processor_pm,
acpi_processor_suspend, acpi_processor_resume);
static struct acpi_driver acpi_processor_driver = {
.name = "processor",
.class = ACPI_PROCESSOR_CLASS,
.ids = processor_device_ids,
.ops = {
.add = acpi_processor_add,
.remove = acpi_processor_remove,
.notify = acpi_processor_notify,
},
.drv.pm = &acpi_processor_pm,
};
#define INSTALL_NOTIFY_HANDLER 1
#define UNINSTALL_NOTIFY_HANDLER 2
DEFINE_PER_CPU(struct acpi_processor *, processors);
EXPORT_PER_CPU_SYMBOL(processors);
struct acpi_processor_errata errata __read_mostly;
/* --------------------------------------------------------------------------
Errata Handling
-------------------------------------------------------------------------- */
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;
}
/* --------------------------------------------------------------------------
Driver Interface
-------------------------------------------------------------------------- */
static int acpi_processor_get_info(struct acpi_device *device)
{
acpi_status status = 0;
union acpi_object object = { 0 };
struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
struct acpi_processor *pr;
int cpu_index, device_declaration = 0;
static int cpu0_initialized;
pr = acpi_driver_data(device);
if (!pr)
return -EINVAL;
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;
}
cpu_index = acpi_get_cpuid(pr->handle, device_declaration, 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) {
if (ACPI_FAILURE(acpi_processor_hotadd_init(pr)))
return -ENODEV;
}
/*
* 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
* 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;
}
static DEFINE_PER_CPU(void *, processor_device_array);
static void acpi_processor_notify(struct acpi_device *device, u32 event)
{
struct acpi_processor *pr = acpi_driver_data(device);
int saved;
if (!pr)
return;
switch (event) {
case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
saved = pr->performance_platform_limit;
acpi_processor_ppc_has_changed(pr, 1);
if (saved == pr->performance_platform_limit)
break;
acpi_bus_generate_proc_event(device, event,
pr->performance_platform_limit);
acpi_bus_generate_netlink_event(device->pnp.device_class,
dev_name(&device->dev), event,
pr->performance_platform_limit);
break;
case ACPI_PROCESSOR_NOTIFY_POWER:
acpi_processor_cst_has_changed(pr);
acpi_bus_generate_proc_event(device, event, 0);
acpi_bus_generate_netlink_event(device->pnp.device_class,
dev_name(&device->dev), event, 0);
break;
case ACPI_PROCESSOR_NOTIFY_THROTTLING:
acpi_processor_tstate_has_changed(pr);
acpi_bus_generate_proc_event(device, event, 0);
acpi_bus_generate_netlink_event(device->pnp.device_class,
dev_name(&device->dev), event, 0);
break;
default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Unsupported event [0x%x]\n", event));
break;
}
return;
}
static int acpi_cpu_soft_notify(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
struct acpi_processor *pr = per_cpu(processors, cpu);
if (action == CPU_ONLINE && pr) {
/* CPU got physically hotplugged and onlined the first time:
* Initialize missing things
*/
if (pr->flags.need_hotplug_init) {
pr_info("Will online and init hotplugged CPU: %d\n",
pr->id);
WARN(acpi_processor_start(pr), "Failed to start CPU:"
" %d\n", pr->id);
pr->flags.need_hotplug_init = 0;
/* Normal CPU soft online event */
} else {
acpi_processor_ppc_has_changed(pr, 0);
acpi_processor_hotplug(pr);
acpi_processor_reevaluate_tstate(pr, action);
acpi_processor_tstate_has_changed(pr);
}
}
if (action == CPU_DEAD && pr) {
/* invalidate the flag.throttling after one CPU is offline */
acpi_processor_reevaluate_tstate(pr, action);
}
return NOTIFY_OK;
}
static struct notifier_block acpi_cpu_notifier =
{
.notifier_call = acpi_cpu_soft_notify,
};
/*
* acpi_processor_start() is called by the cpu_hotplug_notifier func:
* acpi_cpu_soft_notify(). Getting it __cpuinit{data} is difficult, the
* root cause seem to be that acpi_processor_uninstall_hotplug_notify()
* is in the module_exit (__exit) func. Allowing acpi_processor_start()
* to not be in __cpuinit section, but being called from __cpuinit funcs
* via __ref looks like the right thing to do here.
*/
static __ref int acpi_processor_start(struct acpi_processor *pr)
{
struct acpi_device *device = per_cpu(processor_device_array, pr->id);
int result = 0;
#ifdef CONFIG_CPU_FREQ
acpi_processor_ppc_has_changed(pr, 0);
acpi_processor_load_module(pr);
#endif
acpi_processor_get_throttling_info(pr);
acpi_processor_get_limit_info(pr);
if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
acpi_processor_power_init(pr);
pr->cdev = thermal_cooling_device_register("Processor", device,
&processor_cooling_ops);
if (IS_ERR(pr->cdev)) {
result = PTR_ERR(pr->cdev);
goto err_power_exit;
}
dev_dbg(&device->dev, "registered as cooling_device%d\n",
pr->cdev->id);
result = sysfs_create_link(&device->dev.kobj,
&pr->cdev->device.kobj,
"thermal_cooling");
if (result) {
dev_err(&device->dev,
"Failed to create sysfs link 'thermal_cooling'\n");
goto err_thermal_unregister;
}
result = sysfs_create_link(&pr->cdev->device.kobj,
&device->dev.kobj,
"device");
if (result) {
dev_err(&pr->cdev->device,
"Failed to create sysfs link 'device'\n");
goto err_remove_sysfs_thermal;
}
return 0;
err_remove_sysfs_thermal:
sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
err_thermal_unregister:
thermal_cooling_device_unregister(pr->cdev);
err_power_exit:
acpi_processor_power_exit(pr);
return result;
}
/*
* 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 above in acpi_processor_start()
*/
static int __cpuinit acpi_processor_add(struct acpi_device *device)
{
struct acpi_processor *pr = NULL;
int result = 0;
struct device *dev;
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 physically not present */
return 0;
}
#ifdef CONFIG_SMP
if (pr->id >= setup_max_cpus && pr->id != 0)
return 0;
#endif
BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));
/*
* 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);
result = -ENODEV;
goto err_free_cpumask;
}
per_cpu(processor_device_array, pr->id) = device;
per_cpu(processors, pr->id) = pr;
dev = get_cpu_device(pr->id);
if (sysfs_create_link(&device->dev.kobj, &dev->kobj, "sysdev")) {
result = -EFAULT;
goto err_clear_processor;
}
/*
* Do not start hotplugged CPUs now, but when they
* are onlined the first time
*/
if (pr->flags.need_hotplug_init)
return 0;
result = acpi_processor_start(pr);
if (result)
goto err_remove_sysfs;
return 0;
err_remove_sysfs:
sysfs_remove_link(&device->dev.kobj, "sysdev");
err_clear_processor:
/*
* processor_device_array is not cleared to allow checks for buggy BIOS
*/
per_cpu(processors, pr->id) = NULL;
err_free_cpumask:
free_cpumask_var(pr->throttling.shared_cpu_map);
err_free_pr:
kfree(pr);
return result;
}
static int acpi_processor_remove(struct acpi_device *device, int type)
{
struct acpi_processor *pr = NULL;
if (!device || !acpi_driver_data(device))
return -EINVAL;
pr = acpi_driver_data(device);
if (pr->id >= nr_cpu_ids)
goto free;
if (type == ACPI_BUS_REMOVAL_EJECT) {
if (acpi_processor_handle_eject(pr))
return -EINVAL;
}
acpi_processor_power_exit(pr);
sysfs_remove_link(&device->dev.kobj, "sysdev");
if (pr->cdev) {
sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
sysfs_remove_link(&pr->cdev->device.kobj, "device");
thermal_cooling_device_unregister(pr->cdev);
pr->cdev = NULL;
}
per_cpu(processors, pr->id) = NULL;
per_cpu(processor_device_array, pr->id) = NULL;
free:
free_cpumask_var(pr->throttling.shared_cpu_map);
kfree(pr);
return 0;
}
#ifdef CONFIG_ACPI_HOTPLUG_CPU
/****************************************************************************
* Acpi processor hotplug support *
****************************************************************************/
static int is_processor_present(acpi_handle handle)
{
acpi_status status;
unsigned long long sta = 0;
status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
return 1;
/*
* _STA is mandatory for a processor that supports hot plug
*/
if (status == AE_NOT_FOUND)
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Processor does not support hot plug\n"));
else
ACPI_EXCEPTION((AE_INFO, status,
"Processor Device is not present"));
return 0;
}
static
int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
{
acpi_handle phandle;
struct acpi_device *pdev;
if (acpi_get_parent(handle, &phandle)) {
return -ENODEV;
}
if (acpi_bus_get_device(phandle, &pdev)) {
return -ENODEV;
}
if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
return -ENODEV;
}
return 0;
}
static void acpi_processor_hotplug_notify(acpi_handle handle,
u32 event, void *data)
{
struct acpi_device *device = NULL;
struct acpi_eject_event *ej_event = NULL;
u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
int result;
switch (event) {
case ACPI_NOTIFY_BUS_CHECK:
case ACPI_NOTIFY_DEVICE_CHECK:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Processor driver received %s event\n",
(event == ACPI_NOTIFY_BUS_CHECK) ?
"ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
if (!is_processor_present(handle))
break;
if (!acpi_bus_get_device(handle, &device))
break;
result = acpi_processor_device_add(handle, &device);
if (result) {
acpi_handle_err(handle, "Unable to add the device\n");
break;
}
ost_code = ACPI_OST_SC_SUCCESS;
break;
case ACPI_NOTIFY_EJECT_REQUEST:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"received ACPI_NOTIFY_EJECT_REQUEST\n"));
if (acpi_bus_get_device(handle, &device)) {
acpi_handle_err(handle,
"Device don't exist, dropping EJECT\n");
break;
}
if (!acpi_driver_data(device)) {
acpi_handle_err(handle,
"Driver data is NULL, dropping EJECT\n");
break;
}
ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
if (!ej_event) {
acpi_handle_err(handle, "No memory, dropping EJECT\n");
break;
}
ej_event->handle = handle;
ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
(void *)ej_event);
/* eject is performed asynchronously */
return;
default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Unsupported event [0x%x]\n", event));
/* non-hotplug event; possibly handled by other handler */
return;
}
/* Inform firmware that the hotplug operation has completed */
(void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
return;
}
static acpi_status is_processor_device(acpi_handle handle)
{
struct acpi_device_info *info;
char *hid;
acpi_status status;
status = acpi_get_object_info(handle, &info);
if (ACPI_FAILURE(status))
return status;
if (info->type == ACPI_TYPE_PROCESSOR) {
kfree(info);
return AE_OK; /* found a processor object */
}
if (!(info->valid & ACPI_VALID_HID)) {
kfree(info);
return AE_ERROR;
}
hid = info->hardware_id.string;
if ((hid == NULL) || strcmp(hid, ACPI_PROCESSOR_DEVICE_HID)) {
kfree(info);
return AE_ERROR;
}
kfree(info);
return AE_OK; /* found a processor device object */
}
static acpi_status
processor_walk_namespace_cb(acpi_handle handle,
u32 lvl, void *context, void **rv)
{
acpi_status status;
int *action = context;
status = is_processor_device(handle);
if (ACPI_FAILURE(status))
return AE_OK; /* not a processor; continue to walk */
switch (*action) {
case INSTALL_NOTIFY_HANDLER:
acpi_install_notify_handler(handle,
ACPI_SYSTEM_NOTIFY,
acpi_processor_hotplug_notify,
NULL);
break;
case UNINSTALL_NOTIFY_HANDLER:
acpi_remove_notify_handler(handle,
ACPI_SYSTEM_NOTIFY,
acpi_processor_hotplug_notify);
break;
default:
break;
}
/* found a processor; skip walking underneath */
return AE_CTRL_DEPTH;
}
static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
{
acpi_handle handle = pr->handle;
if (!is_processor_present(handle)) {
return AE_ERROR;
}
if (acpi_map_lsapic(handle, &pr->id))
return AE_ERROR;
if (arch_register_cpu(pr->id)) {
acpi_unmap_lsapic(pr->id);
return AE_ERROR;
}
/* CPU got hot-plugged, but cpu_data is not initialized yet
* Set flag to delay cpu_idle/throttling initialization
* in:
* acpi_processor_add()
* acpi_processor_get_info()
* and do it when the CPU gets online the first time
* TBD: Cleanup above functions and try to do this more elegant.
*/
pr_info("CPU %d got hotplugged\n", pr->id);
pr->flags.need_hotplug_init = 1;
return AE_OK;
}
static int acpi_processor_handle_eject(struct acpi_processor *pr)
{
if (cpu_online(pr->id))
cpu_down(pr->id);
get_online_cpus();
/*
* The cpu might become online again at this point. So we check whether
* the cpu has been onlined or not. If the cpu became online, it means
* that someone wants to use the cpu. So acpi_processor_handle_eject()
* returns -EAGAIN.
*/
if (unlikely(cpu_online(pr->id))) {
put_online_cpus();
pr_warn("Failed to remove CPU %d, because other task "
"brought the CPU back online\n", pr->id);
return -EAGAIN;
}
arch_unregister_cpu(pr->id);
acpi_unmap_lsapic(pr->id);
put_online_cpus();
return (0);
}
#else
static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
{
return AE_ERROR;
}
static int acpi_processor_handle_eject(struct acpi_processor *pr)
{
return (-EINVAL);
}
#endif
static
void acpi_processor_install_hotplug_notify(void)
{
#ifdef CONFIG_ACPI_HOTPLUG_CPU
int action = INSTALL_NOTIFY_HANDLER;
acpi_walk_namespace(ACPI_TYPE_ANY,
ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX,
processor_walk_namespace_cb, NULL, &action, NULL);
#endif
register_hotcpu_notifier(&acpi_cpu_notifier);
}
static
void acpi_processor_uninstall_hotplug_notify(void)
{
#ifdef CONFIG_ACPI_HOTPLUG_CPU
int action = UNINSTALL_NOTIFY_HANDLER;
acpi_walk_namespace(ACPI_TYPE_ANY,
ACPI_ROOT_OBJECT,
ACPI_UINT32_MAX,
processor_walk_namespace_cb, NULL, &action, NULL);
#endif
unregister_hotcpu_notifier(&acpi_cpu_notifier);
}
/*
* We keep the driver loaded even when ACPI is not running.
* This is needed for the powernow-k8 driver, that works even without
* ACPI, but needs symbols from this driver
*/
static int __init acpi_processor_init(void)
{
int result = 0;
if (acpi_disabled)
return 0;
result = acpi_bus_register_driver(&acpi_processor_driver);
if (result < 0)
return result;
acpi_processor_install_hotplug_notify();
acpi_thermal_cpufreq_init();
acpi_processor_ppc_init();
acpi_processor_throttling_init();
return 0;
}
static void __exit acpi_processor_exit(void)
{
if (acpi_disabled)
return;
acpi_processor_ppc_exit();
acpi_thermal_cpufreq_exit();
acpi_processor_uninstall_hotplug_notify();
acpi_bus_unregister_driver(&acpi_processor_driver);
return;
}
module_init(acpi_processor_init);
module_exit(acpi_processor_exit);
MODULE_ALIAS("processor");
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