ACPI / processor: Use common hotplug infrastructure
[cascardo/linux.git] / drivers / acpi / processor_driver.c
index c266cdc..ac28f18 100644 (file)
@@ -1,11 +1,13 @@
 /*
- * acpi_processor.c - ACPI Processor Driver ($Revision: 71 $)
+ * processor_driver.c - ACPI Processor Driver
  *
  *  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
+ *  Copyright (C) 2013, Intel Corporation
+ *                      Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
  *  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 <linux/memory_hotplug.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>
 
+#include "internal.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
@@ -81,12 +60,8 @@ 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 int acpi_processor_start(struct device *dev);
+static int acpi_processor_stop(struct device *dev);
 
 static const struct acpi_device_id processor_device_ids[] = {
        {ACPI_PROCESSOR_OBJECT_HID, 0},
@@ -95,295 +70,27 @@ static const struct acpi_device_id processor_device_ids[] = {
 };
 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
 
-static struct acpi_driver acpi_processor_driver = {
+static struct device_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,
-               },
+       .bus = &cpu_subsys,
+       .acpi_match_table = processor_device_ids,
+       .probe = acpi_processor_start,
+       .remove = acpi_processor_stop,
 };
 
-#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)
+static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
 {
-       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_device *device = data;
        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 (device->handle != handle)
+               return;
+
+       pr = acpi_driver_data(device);
        if (!pr)
                return;
 
@@ -420,55 +127,62 @@ static void acpi_processor_notify(struct acpi_device *device, u32 event)
        return;
 }
 
-static int acpi_cpu_soft_notify(struct notifier_block *nfb,
-               unsigned long action, void *hcpu)
+static __cpuinit int __acpi_processor_start(struct acpi_device *device);
+
+static int __cpuinit 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);
+       struct acpi_device *device;
 
-       if (action == CPU_ONLINE && pr) {
-               /* CPU got physically hotplugged and onlined the first time:
-                * Initialize missing things
+       if (!pr || acpi_bus_get_device(pr->handle, &device))
+               return NOTIFY_DONE;
+
+       if (action == CPU_ONLINE) {
+               /*
+                * CPU got physically hotplugged and onlined for the first time:
+                * Initialize missing things.
                 */
                if (pr->flags.need_hotplug_init) {
+                       int ret;
+
                        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 */
+                       ret = __acpi_processor_start(device);
+                       WARN(ret, "Failed to start CPU: %d\n", pr->id);
                } else {
+                       /* Normal CPU soft online event. */
                        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 */
+       } else if (action == CPU_DEAD) {
+               /* Invalidate flag.throttling after the CPU is offline. */
                acpi_processor_reevaluate_tstate(pr, action);
        }
        return NOTIFY_OK;
 }
 
-static struct notifier_block acpi_cpu_notifier =
+static struct notifier_block __refdata 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)
+static __cpuinit int __acpi_processor_start(struct acpi_device *device)
 {
-       struct acpi_device *device = per_cpu(processor_device_array, pr->id);
+       struct acpi_processor *pr = acpi_driver_data(device);
+       acpi_status status;
        int result = 0;
 
+       if (!pr)
+               return -ENODEV;
+
+       if (pr->flags.need_hotplug_init)
+               return 0;
+
 #ifdef CONFIG_CPU_FREQ
        acpi_processor_ppc_has_changed(pr, 0);
        acpi_processor_load_module(pr);
@@ -506,129 +220,48 @@ static __ref int acpi_processor_start(struct acpi_processor *pr)
                goto err_remove_sysfs_thermal;
        }
 
-       return 0;
+       status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
+                                            acpi_processor_notify, device);
+       if (ACPI_SUCCESS(status))
+               return 0;
 
-err_remove_sysfs_thermal:
+       sysfs_remove_link(&pr->cdev->device.kobj, "device");
+ err_remove_sysfs_thermal:
        sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
-err_thermal_unregister:
+ err_thermal_unregister:
        thermal_cooling_device_unregister(pr->cdev);
-err_power_exit:
+ 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)
+static int __cpuinit acpi_processor_start(struct device *dev)
 {
-       struct acpi_processor *pr = NULL;
-       int result = 0;
-       struct device *dev;
-
-       pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
-       if (!pr)
-               return -ENOMEM;
+       struct acpi_device *device;
 
-       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);
-
-       /*
-        * 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;
+       if (acpi_bus_get_device(ACPI_HANDLE(dev), &device))
+               return -ENODEV;
 
-       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;
+       return __acpi_processor_start(device);
 }
 
-static int acpi_processor_remove(struct acpi_device *device)
+static int acpi_processor_stop(struct device *dev)
 {
-       struct acpi_processor *pr = NULL;
+       struct acpi_device *device;
+       struct acpi_processor *pr;
 
+       if (acpi_bus_get_device(ACPI_HANDLE(dev), &device))
+               return 0;
 
-       if (!device || !acpi_driver_data(device))
-               return -EINVAL;
+       acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
+                                  acpi_processor_notify);
 
        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;
-       }
+       if (!pr)
+               return 0;
 
        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");
@@ -637,331 +270,47 @@ static int acpi_processor_remove(struct acpi_device *device)
        }
 
        per_cpu(processors, pr->id) = NULL;
-       per_cpu(processor_device_array, pr->id) = NULL;
-       try_offline_node(cpu_to_node(pr->id));
-
-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)
+static int __init acpi_processor_driver_init(void)
 {
        int result = 0;
 
        if (acpi_disabled)
                return 0;
 
-       result = acpi_bus_register_driver(&acpi_processor_driver);
+       result = driver_register(&acpi_processor_driver);
        if (result < 0)
                return result;
 
        acpi_processor_syscore_init();
-
-       acpi_processor_install_hotplug_notify();
-
+       register_hotcpu_notifier(&acpi_cpu_notifier);
        acpi_thermal_cpufreq_init();
-
        acpi_processor_ppc_init();
-
        acpi_processor_throttling_init();
-
        return 0;
 }
 
-static void __exit acpi_processor_exit(void)
+static void __exit acpi_processor_driver_exit(void)
 {
        if (acpi_disabled)
                return;
 
        acpi_processor_ppc_exit();
-
        acpi_thermal_cpufreq_exit();
-
-       acpi_processor_uninstall_hotplug_notify();
-
+       unregister_hotcpu_notifier(&acpi_cpu_notifier);
        acpi_processor_syscore_exit();
-
-       acpi_bus_unregister_driver(&acpi_processor_driver);
-
-       return;
+       driver_unregister(&acpi_processor_driver);
 }
 
-module_init(acpi_processor_init);
-module_exit(acpi_processor_exit);
+module_init(acpi_processor_driver_init);
+module_exit(acpi_processor_driver_exit);
 
 MODULE_ALIAS("processor");