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processor_core.c

/*
 * 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/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/dmi.h>
#include <linux/moduleparam.h>
#include <linux/cpuidle.h>

#include <asm/io.h>
#include <asm/system.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 ACPI_PROCESSOR_COMPONENT    0x01000000
#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_LIMIT_USER   0
#define ACPI_PROCESSOR_LIMIT_THERMAL      1

#define _COMPONENT            ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_core");

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_start(struct acpi_device *device);
static int acpi_processor_remove(struct acpi_device *device, int type);
static int acpi_processor_info_open_fs(struct inode *inode, struct file *file);
static void acpi_processor_notify(acpi_handle handle, u32 event, void *data);
static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu);
static int acpi_processor_handle_eject(struct acpi_processor *pr);
extern int acpi_processor_tstate_has_changed(struct acpi_processor *pr);


static const struct acpi_device_id processor_device_ids[] = {
      {ACPI_PROCESSOR_HID, 0},
      {"", 0},
};
MODULE_DEVICE_TABLE(acpi, processor_device_ids);

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,
            .start = acpi_processor_start,
            .suspend = acpi_processor_suspend,
            .resume = acpi_processor_resume,
            },
};

#define INSTALL_NOTIFY_HANDLER            1
#define UNINSTALL_NOTIFY_HANDLER    2

static const struct file_operations acpi_processor_info_fops = {
      .open = acpi_processor_info_open_fs,
      .read = seq_read,
      .llseek = seq_lseek,
      .release = single_release,
};

struct acpi_processor *processors[NR_CPUS];
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;
}

/* --------------------------------------------------------------------------
                              Common ACPI processor functions
   -------------------------------------------------------------------------- */

/*
 * _PDC is required for a BIOS-OS handshake for most of the newer
 * ACPI processor features.
 */
static int acpi_processor_set_pdc(struct acpi_processor *pr)
{
      struct acpi_object_list *pdc_in = pr->pdc;
      acpi_status status = AE_OK;


      if (!pdc_in)
            return status;

      status = acpi_evaluate_object(pr->handle, "_PDC", pdc_in, NULL);

      if (ACPI_FAILURE(status))
            ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                "Could not evaluate _PDC, using legacy perf. control...\n"));

      return status;
}

/* --------------------------------------------------------------------------
                              FS Interface (/proc)
   -------------------------------------------------------------------------- */

static struct proc_dir_entry *acpi_processor_dir = NULL;

static int acpi_processor_info_seq_show(struct seq_file *seq, void *offset)
{
      struct acpi_processor *pr = seq->private;


      if (!pr)
            goto end;

      seq_printf(seq, "processor id:            %d\n"
               "acpi id:                 %d\n"
               "bus mastering control:   %s\n"
               "power management:        %s\n"
               "throttling control:      %s\n"
               "limit interface:         %s\n",
               pr->id,
               pr->acpi_id,
               pr->flags.bm_control ? "yes" : "no",
               pr->flags.power ? "yes" : "no",
               pr->flags.throttling ? "yes" : "no",
               pr->flags.limit ? "yes" : "no");

      end:
      return 0;
}

static int acpi_processor_info_open_fs(struct inode *inode, struct file *file)
{
      return single_open(file, acpi_processor_info_seq_show,
                     PDE(inode)->data);
}

static int acpi_processor_add_fs(struct acpi_device *device)
{
      struct proc_dir_entry *entry = NULL;


      if (!acpi_device_dir(device)) {
            acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
                                         acpi_processor_dir);
            if (!acpi_device_dir(device))
                  return -ENODEV;
      }
      acpi_device_dir(device)->owner = THIS_MODULE;

      /* 'info' [R] */
      entry = create_proc_entry(ACPI_PROCESSOR_FILE_INFO,
                          S_IRUGO, acpi_device_dir(device));
      if (!entry)
            return -EIO;
      else {
            entry->proc_fops = &acpi_processor_info_fops;
            entry->data = acpi_driver_data(device);
            entry->owner = THIS_MODULE;
      }

      /* 'throttling' [R/W] */
      entry = create_proc_entry(ACPI_PROCESSOR_FILE_THROTTLING,
                          S_IFREG | S_IRUGO | S_IWUSR,
                          acpi_device_dir(device));
      if (!entry)
            return -EIO;
      else {
            entry->proc_fops = &acpi_processor_throttling_fops;
            entry->data = acpi_driver_data(device);
            entry->owner = THIS_MODULE;
      }

      /* 'limit' [R/W] */
      entry = create_proc_entry(ACPI_PROCESSOR_FILE_LIMIT,
                          S_IFREG | S_IRUGO | S_IWUSR,
                          acpi_device_dir(device));
      if (!entry)
            return -EIO;
      else {
            entry->proc_fops = &acpi_processor_limit_fops;
            entry->data = acpi_driver_data(device);
            entry->owner = THIS_MODULE;
      }

      return 0;
}

static int acpi_processor_remove_fs(struct acpi_device *device)
{

      if (acpi_device_dir(device)) {
            remove_proc_entry(ACPI_PROCESSOR_FILE_INFO,
                          acpi_device_dir(device));
            remove_proc_entry(ACPI_PROCESSOR_FILE_THROTTLING,
                          acpi_device_dir(device));
            remove_proc_entry(ACPI_PROCESSOR_FILE_LIMIT,
                          acpi_device_dir(device));
            remove_proc_entry(acpi_device_bid(device), acpi_processor_dir);
            acpi_device_dir(device) = NULL;
      }

      return 0;
}

/* Use the acpiid in MADT to map cpus in case of SMP */

#ifndef CONFIG_SMP
static int get_cpu_id(acpi_handle handle, u32 acpi_id) {return -1;}
#else

static struct acpi_table_madt *madt;

static int map_lapic_id(struct acpi_subtable_header *entry,
             u32 acpi_id, int *apic_id)
{
      struct acpi_madt_local_apic *lapic =
            (struct acpi_madt_local_apic *)entry;
      if ((lapic->lapic_flags & ACPI_MADT_ENABLED) &&
          lapic->processor_id == acpi_id) {
            *apic_id = lapic->id;
            return 1;
      }
      return 0;
}

static int map_lsapic_id(struct acpi_subtable_header *entry,
              u32 acpi_id, int *apic_id)
{
      struct acpi_madt_local_sapic *lsapic =
            (struct acpi_madt_local_sapic *)entry;
      /* Only check enabled APICs*/
      if (lsapic->lapic_flags & ACPI_MADT_ENABLED) {
            /* First check against id */
            if (lsapic->processor_id == acpi_id) {
                  *apic_id = (lsapic->id << 8) | lsapic->eid;
                  return 1;
            /* Check against optional uid */
            } else if (entry->length >= 16 &&
                  lsapic->uid == acpi_id) {
                  *apic_id = lsapic->uid;
                  return 1;
            }
      }
      return 0;
}

static int map_madt_entry(u32 acpi_id)
{
      unsigned long madt_end, entry;
      int apic_id = -1;

      if (!madt)
            return apic_id;

      entry = (unsigned long)madt;
      madt_end = entry + madt->header.length;

      /* Parse all entries looking for a match. */

      entry += sizeof(struct acpi_table_madt);
      while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
            struct acpi_subtable_header *header =
                  (struct acpi_subtable_header *)entry;
            if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
                  if (map_lapic_id(header, acpi_id, &apic_id))
                        break;
            } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
                  if (map_lsapic_id(header, acpi_id, &apic_id))
                        break;
            }
            entry += header->length;
      }
      return apic_id;
}

static int map_mat_entry(acpi_handle handle, u32 acpi_id)
{
      struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
      union acpi_object *obj;
      struct acpi_subtable_header *header;
      int apic_id = -1;

      if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
            goto exit;

      if (!buffer.length || !buffer.pointer)
            goto exit;

      obj = buffer.pointer;
      if (obj->type != ACPI_TYPE_BUFFER ||
          obj->buffer.length < sizeof(struct acpi_subtable_header)) {
            goto exit;
      }

      header = (struct acpi_subtable_header *)obj->buffer.pointer;
      if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
            map_lapic_id(header, acpi_id, &apic_id);
      } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
            map_lsapic_id(header, acpi_id, &apic_id);
      }

exit:
      if (buffer.pointer)
            kfree(buffer.pointer);
      return apic_id;
}

static int get_cpu_id(acpi_handle handle, u32 acpi_id)
{
      int i;
      int apic_id = -1;

      apic_id = map_mat_entry(handle, acpi_id);
      if (apic_id == -1)
            apic_id = map_madt_entry(acpi_id);
      if (apic_id == -1)
            return apic_id;

      for_each_possible_cpu(i) {
            if (cpu_physical_id(i) == apic_id)
                  return i;
      }
      return -1;
}
#endif

/* --------------------------------------------------------------------------
                                 Driver Interface
   -------------------------------------------------------------------------- */

static int acpi_processor_get_info(struct acpi_processor *pr, unsigned has_uid)
{
      acpi_status status = 0;
      union acpi_object object = { 0 };
      struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
      int cpu_index;
      static int cpu0_initialized;


      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"));

      /* Check if it is a Device with HID and UID */
      if (has_uid) {
            unsigned long value;
            status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
                                    NULL, &value);
            if (ACPI_FAILURE(status)) {
                  printk(KERN_ERR PREFIX "Evaluating processor _UID\n");
                  return -ENODEV;
            }
            pr->acpi_id = value;
      } else {
            /*
            * Evalute the processor object.  Note that it is common on SMP to
            * have the first (boot) processor with a valid PBLK address while
            * all others have a NULL address.
            */
            status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
            if (ACPI_FAILURE(status)) {
                  printk(KERN_ERR PREFIX "Evaluating processor object\n");
                  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;
      }
      cpu_index = get_cpu_id(pr->handle, 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->handle, &pr->id))) {
                  return -ENODEV;
            }
      }

      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)
            printk(KERN_ERR PREFIX "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");
      }

      return 0;
}

static void *processor_device_array[NR_CPUS];

static int __cpuinit acpi_processor_start(struct acpi_device *device)
{
      int result = 0;
      acpi_status status = AE_OK;
      struct acpi_processor *pr;


      pr = acpi_driver_data(device);

      result = acpi_processor_get_info(pr, device->flags.unique_id);
      if (result) {
            /* Processor is physically not present */
            return 0;
      }

      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 (processor_device_array[pr->id] != NULL &&
          processor_device_array[pr->id] != device) {
            printk(KERN_WARNING "BIOS reported wrong ACPI id "
                  "for the processor\n");
            return -ENODEV;
      }
      processor_device_array[pr->id] = device;

      processors[pr->id] = pr;

      result = acpi_processor_add_fs(device);
      if (result)
            goto end;

      status = acpi_install_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY,
                                   acpi_processor_notify, pr);

      /* _PDC call should be done before doing anything else (if reqd.). */
      arch_acpi_processor_init_pdc(pr);
      acpi_processor_set_pdc(pr);
#ifdef CONFIG_CPU_FREQ
      acpi_processor_ppc_has_changed(pr);
#endif
      acpi_processor_get_throttling_info(pr);
      acpi_processor_get_limit_info(pr);


      acpi_processor_power_init(pr, device);

      if (pr->flags.throttling) {
            printk(KERN_INFO PREFIX "%s [%s] (supports",
                   acpi_device_name(device), acpi_device_bid(device));
            printk(" %d throttling states", pr->throttling.state_count);
            printk(")\n");
      }

      end:

      return result;
}

static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
{
      struct acpi_processor *pr = data;
      struct acpi_device *device = NULL;
      int saved;

      if (!pr)
            return;

      if (acpi_bus_get_device(pr->handle, &device))
            return;

      switch (event) {
      case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
            saved = pr->performance_platform_limit;
            acpi_processor_ppc_has_changed(pr);
            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,
                                      device->dev.bus_id, 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,
                                      device->dev.bus_id, 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,
                                      device->dev.bus_id, event, 0);
      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 = processors[cpu];

      if (action == CPU_ONLINE && pr) {
            acpi_processor_ppc_has_changed(pr);
            acpi_processor_cst_has_changed(pr);
            acpi_processor_tstate_has_changed(pr);
      }
      return NOTIFY_OK;
}

static struct notifier_block acpi_cpu_notifier =
{
          .notifier_call = acpi_cpu_soft_notify,
};

static int acpi_processor_add(struct acpi_device *device)
{
      struct acpi_processor *pr = NULL;


      if (!device)
            return -EINVAL;

      pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
      if (!pr)
            return -ENOMEM;

      pr->handle = device->handle;
      strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
      strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
      acpi_driver_data(device) = pr;

      return 0;
}

static int acpi_processor_remove(struct acpi_device *device, int type)
{
      acpi_status status = AE_OK;
      struct acpi_processor *pr = NULL;


      if (!device || !acpi_driver_data(device))
            return -EINVAL;

      pr = acpi_driver_data(device);

      if (pr->id >= nr_cpu_ids) {
            kfree(pr);
            return 0;
      }

      if (type == ACPI_BUS_REMOVAL_EJECT) {
            if (acpi_processor_handle_eject(pr))
                  return -EINVAL;
      }

      acpi_processor_power_exit(pr, device);

      status = acpi_remove_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY,
                                  acpi_processor_notify);

      acpi_processor_remove_fs(device);

      processors[pr->id] = NULL;

      kfree(pr);

      return 0;
}

#ifdef CONFIG_ACPI_HOTPLUG_CPU
/****************************************************************************
 *    Acpi processor hotplug support                                        *
 ****************************************************************************/

static int is_processor_present(acpi_handle handle);

static int is_processor_present(acpi_handle handle)
{
      acpi_status status;
      unsigned long sta = 0;


      status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
      if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) {
            ACPI_EXCEPTION((AE_INFO, status, "Processor Device is not present"));
            return 0;
      }
      return 1;
}

static
int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
{
      acpi_handle phandle;
      struct acpi_device *pdev;
      struct acpi_processor *pr;


      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;
      }

      acpi_bus_start(*device);

      pr = acpi_driver_data(*device);
      if (!pr)
            return -ENODEV;

      if ((pr->id >= 0) && (pr->id < nr_cpu_ids)) {
            kobject_uevent(&(*device)->dev.kobj, KOBJ_ONLINE);
      }
      return 0;
}

static void
acpi_processor_hotplug_notify(acpi_handle handle, u32 event, void *data)
{
      struct acpi_processor *pr;
      struct acpi_device *device = NULL;
      int result;


      switch (event) {
      case ACPI_NOTIFY_BUS_CHECK:
      case ACPI_NOTIFY_DEVICE_CHECK:
            printk("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)) {
                  result = acpi_processor_device_add(handle, &device);
                  if (result)
                        printk(KERN_ERR PREFIX
                                  "Unable to add the device\n");
                  break;
            }

            pr = acpi_driver_data(device);
            if (!pr) {
                  printk(KERN_ERR PREFIX "Driver data is NULL\n");
                  break;
            }

            if (pr->id >= 0 && (pr->id < nr_cpu_ids)) {
                  kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
                  break;
            }

            result = acpi_processor_start(device);
            if ((!result) && ((pr->id >= 0) && (pr->id < nr_cpu_ids))) {
                  kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
            } else {
                  printk(KERN_ERR PREFIX "Device [%s] failed to start\n",
                            acpi_device_bid(device));
            }
            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)) {
                  printk(KERN_ERR PREFIX
                            "Device don't exist, dropping EJECT\n");
                  break;
            }
            pr = acpi_driver_data(device);
            if (!pr) {
                  printk(KERN_ERR PREFIX
                            "Driver data is NULL, dropping EJECT\n");
                  return;
            }

            if ((pr->id < nr_cpu_ids) && (cpu_present(pr->id)))
                  kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
            break;
      default:
            ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "Unsupported event [0x%x]\n", event));
            break;
      }

      return;
}

static acpi_status
processor_walk_namespace_cb(acpi_handle handle,
                      u32 lvl, void *context, void **rv)
{
      acpi_status status;
      int *action = context;
      acpi_object_type type = 0;

      status = acpi_get_type(handle, &type);
      if (ACPI_FAILURE(status))
            return (AE_OK);

      if (type != ACPI_TYPE_PROCESSOR)
            return (AE_OK);

      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;
      }

      return (AE_OK);
}

static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
{

      if (!is_processor_present(handle)) {
            return AE_ERROR;
      }

      if (acpi_map_lsapic(handle, p_cpu))
            return AE_ERROR;

      if (arch_register_cpu(*p_cpu)) {
            acpi_unmap_lsapic(*p_cpu);
            return AE_ERROR;
      }

      return AE_OK;
}

static int acpi_processor_handle_eject(struct acpi_processor *pr)
{
      if (cpu_online(pr->id)) {
            return (-EINVAL);
      }
      arch_unregister_cpu(pr->id);
      acpi_unmap_lsapic(pr->id);
      return (0);
}
#else
static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
{
      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_PROCESSOR,
                      ACPI_ROOT_OBJECT,
                      ACPI_UINT32_MAX,
                      processor_walk_namespace_cb, &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_PROCESSOR,
                      ACPI_ROOT_OBJECT,
                      ACPI_UINT32_MAX,
                      processor_walk_namespace_cb, &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;


      memset(&processors, 0, sizeof(processors));
      memset(&errata, 0, sizeof(errata));

#ifdef CONFIG_SMP
      if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
                        (struct acpi_table_header **)&madt)))
            madt = NULL;
#endif

      acpi_processor_dir = proc_mkdir(ACPI_PROCESSOR_CLASS, acpi_root_dir);
      if (!acpi_processor_dir)
            return -ENOMEM;
      acpi_processor_dir->owner = THIS_MODULE;

      result = cpuidle_register_driver(&acpi_idle_driver);
      if (result < 0)
            goto out_proc;

      result = acpi_bus_register_driver(&acpi_processor_driver);
      if (result < 0)
            goto out_cpuidle;

      acpi_processor_install_hotplug_notify();

      acpi_thermal_cpufreq_init();

      acpi_processor_ppc_init();

      return 0;

out_cpuidle:
      cpuidle_unregister_driver(&acpi_idle_driver);

out_proc:
      remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);

      return result;
}

static void __exit acpi_processor_exit(void)
{
      acpi_processor_ppc_exit();

      acpi_thermal_cpufreq_exit();

      acpi_processor_uninstall_hotplug_notify();

      acpi_bus_unregister_driver(&acpi_processor_driver);

      cpuidle_unregister_driver(&acpi_idle_driver);

      remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);

      return;
}

module_init(acpi_processor_init);
module_exit(acpi_processor_exit);

EXPORT_SYMBOL(acpi_processor_set_thermal_limit);

MODULE_ALIAS("processor");

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