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kernel_optimize_test/drivers/acpi/processor_driver.c
Rafael J. Wysocki 3757b94802 ACPI / hotplug: Fix concurrency issues and memory leaks 
This changeset is aimed at fixing a few different but related
problems in the ACPI hotplug infrastructure.

First of all, since notify handlers may be run in parallel with
acpi_bus_scan(), acpi_bus_trim() and acpi_bus_hot_remove_device()
and some of them are installed for ACPI handles that have no struct
acpi_device objects attached (i.e. before those objects are created),
those notify handlers have to take acpi_scan_lock to prevent races
from taking place (e.g. a struct acpi_device is found to be present
for the given ACPI handle, but right after that it is removed by
acpi_bus_trim() running in parallel to the given notify handler).
Moreover, since some of them call acpi_bus_scan() and
acpi_bus_trim(), this leads to the conclusion that acpi_scan_lock
should be acquired by the callers of these two funtions rather by
these functions themselves.

For these reasons, make all notify handlers that can handle device
addition and eject events take acpi_scan_lock and remove the
acpi_scan_lock locking from acpi_bus_scan() and acpi_bus_trim().
Accordingly, update all of their users to make sure that they
are always called under acpi_scan_lock.

Furthermore, since eject operations are carried out asynchronously
with respect to the notify events that trigger them, with the help
of acpi_bus_hot_remove_device(), even if notify handlers take the
ACPI scan lock, it still is possible that, for example,
acpi_bus_trim() will run between acpi_bus_hot_remove_device() and
the notify handler that scheduled its execution and that
acpi_bus_trim() will remove the device node passed to
acpi_bus_hot_remove_device() for ejection.  In that case, the struct
acpi_device object obtained by acpi_bus_hot_remove_device() will be
invalid and not-so-funny things will ensue.  To protect agaist that,
make the users of acpi_bus_hot_remove_device() run get_device() on
ACPI device node objects that are about to be passed to it and make
acpi_bus_hot_remove_device() run put_device() on them and check if
their ACPI handles are not NULL (make acpi_device_unregister() clear
the device nodes' ACPI handles for that check to work).

Finally, observe that acpi_os_hotplug_execute() actually can fail,
in which case its caller ought to free memory allocated for the
context object to prevent leaks from happening.  It also needs to
run put_device() on the device node that it ran get_device() on
previously in that case.  Modify the code accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
2013-02-13 14:36:47 +01:00

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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);
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)
{
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 (device->removal_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 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 */
acpi_status status;
int result;
acpi_scan_lock_acquire();
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_bus_scan(handle);
if (result) {
acpi_handle_err(handle, "Unable to add the device\n");
break;
}
result = acpi_bus_get_device(handle, &device);
if (result) {
acpi_handle_err(handle, "Missing device object\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;
}
get_device(&device->dev);
ej_event->device = device;
ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
/* The eject is carried out asynchronously. */
status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
ej_event);
if (ACPI_FAILURE(status)) {
put_device(&device->dev);
kfree(ej_event);
break;
}
goto out;
default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Unsupported event [0x%x]\n", event));
/* non-hotplug event; possibly handled by other handler */
goto out;
}
/* Inform firmware that the hotplug operation has completed */
(void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
out:
acpi_scan_lock_release();
}
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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