processor_perflib.c

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/*
 * processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <[email protected]>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
 *  Copyright (C) 2004       Dominik Brodowski <[email protected]>
 *  Copyright (C) 2004  Anil S Keshavamurthy <[email protected]>
 *              - 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.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/slab.h>

#ifdef CONFIG_X86
#include <asm/cpufeature.h>
#endif

#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_FILE_PERFORMANCE "performance"
#define _COMPONENT      ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_perflib");

static DEFINE_MUTEX(performance_mutex);

/*
 * _PPC support is implemented as a CPUfreq policy notifier:
 * This means each time a CPUfreq driver registered also with
 * the ACPI core is asked to change the speed policy, the maximum
 * value is adjusted so that it is within the platform limit.
 *
 * Also, when a new platform limit value is detected, the CPUfreq
 * policy is adjusted accordingly.
 */

/* ignore_ppc:
 * -1 -> cpufreq low level drivers not initialized -> _PSS, etc. not called yet
 *       ignore _PPC
 *  0 -> cpufreq low level drivers initialized -> consider _PPC values
 *  1 -> ignore _PPC totally -> forced by user through boot param
 */
static int ignore_ppc = -1;
module_param(ignore_ppc, int, 0644);
MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \
         "limited by BIOS, this should help");

#define PPC_REGISTERED   1
#define PPC_IN_USE       2

static int acpi_processor_ppc_status;

static int acpi_processor_ppc_notifier(struct notifier_block *nb,
                       unsigned long event, void *data)
{
    struct cpufreq_policy *policy = data;
    struct acpi_processor *pr;
    unsigned int ppc = 0;

    if (event == CPUFREQ_START && ignore_ppc <= 0) {
        ignore_ppc = 0;
        return 0;
    }

    if (ignore_ppc)
        return 0;

    if (event != CPUFREQ_INCOMPATIBLE)
        return 0;

    mutex_lock(&performance_mutex);

    pr = per_cpu(processors, policy->cpu);
    if (!pr || !pr->performance)
        goto out;

    ppc = (unsigned int)pr->performance_platform_limit;

    if (ppc >= pr->performance->state_count)
        goto out;

    cpufreq_verify_within_limits(policy, 0,
                     pr->performance->states[ppc].
                     core_frequency * 1000);

      out:
    mutex_unlock(&performance_mutex);

    return 0;
}

static struct notifier_block acpi_ppc_notifier_block = {
    .notifier_call = acpi_processor_ppc_notifier,
};

static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
{
    acpi_status status = 0;
    unsigned long long ppc = 0;


    if (!pr)
        return -EINVAL;

    /*
     * _PPC indicates the maximum state currently supported by the platform
     * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
     */
    status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);

    if (status != AE_NOT_FOUND)
        acpi_processor_ppc_status |= PPC_IN_USE;

    if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
        ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PPC"));
        return -ENODEV;
    }

    pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id,
               (int)ppc, ppc ? "" : "not");

    pr->performance_platform_limit = (int)ppc;

    return 0;
}

#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE   0x80
/*
 * acpi_processor_ppc_ost: Notify firmware the _PPC evaluation status
 * @handle: ACPI processor handle
 * @status: the status code of _PPC evaluation
 *  0: success. OSPM is now using the performance state specificed.
 *  1: failure. OSPM has not changed the number of P-states in use
 */
static void acpi_processor_ppc_ost(acpi_handle handle, int status)
{
    union acpi_object params[2] = {
        {.type = ACPI_TYPE_INTEGER,},
        {.type = ACPI_TYPE_INTEGER,},
    };
    struct acpi_object_list arg_list = {2, params};
    acpi_handle temp;

    params[0].integer.value = ACPI_PROCESSOR_NOTIFY_PERFORMANCE;
    params[1].integer.value =  status;

    /* when there is no _OST , skip it */
    if (ACPI_FAILURE(acpi_get_handle(handle, "_OST", &temp)))
        return;

    acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
    return;
}

int acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
{
    int ret;

    if (ignore_ppc) {
        /*
         * Only when it is notification event, the _OST object
         * will be evaluated. Otherwise it is skipped.
         */
        if (event_flag)
            acpi_processor_ppc_ost(pr->handle, 1);
        return 0;
    }

    ret = acpi_processor_get_platform_limit(pr);
    /*
     * Only when it is notification event, the _OST object
     * will be evaluated. Otherwise it is skipped.
     */
    if (event_flag) {
        if (ret < 0)
            acpi_processor_ppc_ost(pr->handle, 1);
        else
            acpi_processor_ppc_ost(pr->handle, 0);
    }
    if (ret < 0)
        return (ret);
    else
        return cpufreq_update_policy(pr->id);
}

int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
{
    struct acpi_processor *pr;

    pr = per_cpu(processors, cpu);
    if (!pr || !pr->performance || !pr->performance->state_count)
        return -ENODEV;
    *limit = pr->performance->states[pr->performance_platform_limit].
        core_frequency * 1000;
    return 0;
}
EXPORT_SYMBOL(acpi_processor_get_bios_limit);

void acpi_processor_ppc_init(void)
{
    if (!cpufreq_register_notifier
        (&acpi_ppc_notifier_block, CPUFREQ_POLICY_NOTIFIER))
        acpi_processor_ppc_status |= PPC_REGISTERED;
    else
        printk(KERN_DEBUG
               "Warning: Processor Platform Limit not supported.\n");
}

void acpi_processor_ppc_exit(void)
{
    if (acpi_processor_ppc_status & PPC_REGISTERED)
        cpufreq_unregister_notifier(&acpi_ppc_notifier_block,
                        CPUFREQ_POLICY_NOTIFIER);

    acpi_processor_ppc_status &= ~PPC_REGISTERED;
}

/*
 * Do a quick check if the systems looks like it should use ACPI
 * cpufreq. We look at a _PCT method being available, but don't
 * do a whole lot of sanity checks.
 */
void acpi_processor_load_module(struct acpi_processor *pr)
{
    static int requested;
    acpi_status status = 0;
    struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

    if (!arch_has_acpi_pdc() || requested)
        return;
    status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
    if (!ACPI_FAILURE(status)) {
        printk(KERN_INFO PREFIX "Requesting acpi_cpufreq\n");
        request_module_nowait("acpi_cpufreq");
        requested = 1;
    }
    kfree(buffer.pointer);
}

static int acpi_processor_get_performance_control(struct acpi_processor *pr)
{
    int result = 0;
    acpi_status status = 0;
    struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
    union acpi_object *pct = NULL;
    union acpi_object obj = { 0 };


    status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
    if (ACPI_FAILURE(status)) {
        ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PCT"));
        return -ENODEV;
    }

    pct = (union acpi_object *)buffer.pointer;
    if (!pct || (pct->type != ACPI_TYPE_PACKAGE)
        || (pct->package.count != 2)) {
        printk(KERN_ERR PREFIX "Invalid _PCT data\n");
        result = -EFAULT;
        goto end;
    }

    /*
     * control_register
     */

    obj = pct->package.elements[0];

    if ((obj.type != ACPI_TYPE_BUFFER)
        || (obj.buffer.length < sizeof(struct acpi_pct_register))
        || (obj.buffer.pointer == NULL)) {
        printk(KERN_ERR PREFIX "Invalid _PCT data (control_register)\n");
        result = -EFAULT;
        goto end;
    }
    memcpy(&pr->performance->control_register, obj.buffer.pointer,
           sizeof(struct acpi_pct_register));

    /*
     * status_register
     */

    obj = pct->package.elements[1];

    if ((obj.type != ACPI_TYPE_BUFFER)
        || (obj.buffer.length < sizeof(struct acpi_pct_register))
        || (obj.buffer.pointer == NULL)) {
        printk(KERN_ERR PREFIX "Invalid _PCT data (status_register)\n");
        result = -EFAULT;
        goto end;
    }

    memcpy(&pr->performance->status_register, obj.buffer.pointer,
           sizeof(struct acpi_pct_register));

      end:
    kfree(buffer.pointer);

    return result;
}

#ifdef CONFIG_X86
/*
 * Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding
 * in their ACPI data. Calculate the real values and fix up the _PSS data.
 */
static void amd_fixup_frequency(struct acpi_processor_px *px, int i)
{
    u32 hi, lo, fid, did;
    int index = px->control & 0x00000007;

    if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
        return;

    if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
        || boot_cpu_data.x86 == 0x11) {
        rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi);
        fid = lo & 0x3f;
        did = (lo >> 6) & 7;
        if (boot_cpu_data.x86 == 0x10)
            px->core_frequency = (100 * (fid + 0x10)) >> did;
        else
            px->core_frequency = (100 * (fid + 8)) >> did;
    }
}
#else
static void amd_fixup_frequency(struct acpi_processor_px *px, int i) {};
#endif

static int acpi_processor_get_performance_states(struct acpi_processor *pr)
{
    int result = 0;
    acpi_status status = AE_OK;
    struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
    struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" };
    struct acpi_buffer state = { 0, NULL };
    union acpi_object *pss = NULL;
    int i;
    int last_invalid = -1;


    status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
    if (ACPI_FAILURE(status)) {
        ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PSS"));
        return -ENODEV;
    }

    pss = buffer.pointer;
    if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
        printk(KERN_ERR PREFIX "Invalid _PSS data\n");
        result = -EFAULT;
        goto end;
    }

    ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d performance states\n",
              pss->package.count));

    pr->performance->state_count = pss->package.count;
    pr->performance->states =
        kmalloc(sizeof(struct acpi_processor_px) * pss->package.count,
            GFP_KERNEL);
    if (!pr->performance->states) {
        result = -ENOMEM;
        goto end;
    }

    for (i = 0; i < pr->performance->state_count; i++) {

        struct acpi_processor_px *px = &(pr->performance->states[i]);

        state.length = sizeof(struct acpi_processor_px);
        state.pointer = px;

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));

        status = acpi_extract_package(&(pss->package.elements[i]),
                          &format, &state);
        if (ACPI_FAILURE(status)) {
            ACPI_EXCEPTION((AE_INFO, status, "Invalid _PSS data"));
            result = -EFAULT;
            kfree(pr->performance->states);
            goto end;
        }

        amd_fixup_frequency(px, i);

        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                  "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
                  i,
                  (u32) px->core_frequency,
                  (u32) px->power,
                  (u32) px->transition_latency,
                  (u32) px->bus_master_latency,
                  (u32) px->control, (u32) px->status));

        /*
         * Check that ACPI's u64 MHz will be valid as u32 KHz in cpufreq
         */
        if (!px->core_frequency ||
            ((u32)(px->core_frequency * 1000) !=
             (px->core_frequency * 1000))) {
            printk(KERN_ERR FW_BUG PREFIX
                   "Invalid BIOS _PSS frequency found for processor %d: 0x%llx MHz\n",
                   pr->id, px->core_frequency);
            if (last_invalid == -1)
                last_invalid = i;
        } else {
            if (last_invalid != -1) {
                /*
                 * Copy this valid entry over last_invalid entry
                 */
                memcpy(&(pr->performance->states[last_invalid]),
                       px, sizeof(struct acpi_processor_px));
                ++last_invalid;
            }
        }
    }

    if (last_invalid == 0) {
        printk(KERN_ERR FW_BUG PREFIX
               "No valid BIOS _PSS frequency found for processor %d\n", pr->id);
        result = -EFAULT;
        kfree(pr->performance->states);
        pr->performance->states = NULL;
    }

    if (last_invalid > 0)
        pr->performance->state_count = last_invalid;

      end:
    kfree(buffer.pointer);

    return result;
}

static int acpi_processor_get_performance_info(struct acpi_processor *pr)
{
    int result = 0;
    acpi_status status = AE_OK;
    acpi_handle handle = NULL;

    if (!pr || !pr->performance || !pr->handle)
        return -EINVAL;

    status = acpi_get_handle(pr->handle, "_PCT", &handle);
    if (ACPI_FAILURE(status)) {
        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                  "ACPI-based processor performance control unavailable\n"));
        return -ENODEV;
    }

    result = acpi_processor_get_performance_control(pr);
    if (result)
        goto update_bios;

    result = acpi_processor_get_performance_states(pr);
    if (result)
        goto update_bios;

    /* We need to call _PPC once when cpufreq starts */
    if (ignore_ppc != 1)
        result = acpi_processor_get_platform_limit(pr);

    return result;

    /*
     * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that
     * the BIOS is older than the CPU and does not know its frequencies
     */
 update_bios:
#ifdef CONFIG_X86
    if (ACPI_SUCCESS(acpi_get_handle(pr->handle, "_PPC", &handle))){
        if(boot_cpu_has(X86_FEATURE_EST))
            printk(KERN_WARNING FW_BUG "BIOS needs update for CPU "
                   "frequency support\n");
    }
#endif
    return result;
}

int acpi_processor_notify_smm(struct module *calling_module)
{
    acpi_status status;
    static int is_done = 0;


    if (!(acpi_processor_ppc_status & PPC_REGISTERED))
        return -EBUSY;

    if (!try_module_get(calling_module))
        return -EINVAL;

    /* is_done is set to negative if an error occurred,
     * and to postitive if _no_ error occurred, but SMM
     * was already notified. This avoids double notification
     * which might lead to unexpected results...
     */
    if (is_done > 0) {
        module_put(calling_module);
        return 0;
    } else if (is_done < 0) {
        module_put(calling_module);
        return is_done;
    }

    is_done = -EIO;

    /* Can't write pstate_control to smi_command if either value is zero */
    if ((!acpi_gbl_FADT.smi_command) || (!acpi_gbl_FADT.pstate_control)) {
        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No SMI port or pstate_control\n"));
        module_put(calling_module);
        return 0;
    }

    ACPI_DEBUG_PRINT((ACPI_DB_INFO,
              "Writing pstate_control [0x%x] to smi_command [0x%x]\n",
              acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command));

    status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
                    (u32) acpi_gbl_FADT.pstate_control, 8);
    if (ACPI_FAILURE(status)) {
        ACPI_EXCEPTION((AE_INFO, status,
                "Failed to write pstate_control [0x%x] to "
                "smi_command [0x%x]", acpi_gbl_FADT.pstate_control,
                acpi_gbl_FADT.smi_command));
        module_put(calling_module);
        return status;
    }

    /* Success. If there's no _PPC, we need to fear nothing, so
     * we can allow the cpufreq driver to be rmmod'ed. */
    is_done = 1;

    if (!(acpi_processor_ppc_status & PPC_IN_USE))
        module_put(calling_module);

    return 0;
}

EXPORT_SYMBOL(acpi_processor_notify_smm);

static int acpi_processor_get_psd(struct acpi_processor *pr)
{
    int result = 0;
    acpi_status status = AE_OK;
    struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
    struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};
    struct acpi_buffer state = {0, NULL};
    union acpi_object  *psd = NULL;
    struct acpi_psd_package *pdomain;

    status = acpi_evaluate_object(pr->handle, "_PSD", NULL, &buffer);
    if (ACPI_FAILURE(status)) {
        return -ENODEV;
    }

    psd = buffer.pointer;
    if (!psd || (psd->type != ACPI_TYPE_PACKAGE)) {
        printk(KERN_ERR PREFIX "Invalid _PSD data\n");
        result = -EFAULT;
        goto end;
    }

    if (psd->package.count != 1) {
        printk(KERN_ERR PREFIX "Invalid _PSD data\n");
        result = -EFAULT;
        goto end;
    }

    pdomain = &(pr->performance->domain_info);

    state.length = sizeof(struct acpi_psd_package);
    state.pointer = pdomain;

    status = acpi_extract_package(&(psd->package.elements[0]),
        &format, &state);
    if (ACPI_FAILURE(status)) {
        printk(KERN_ERR PREFIX "Invalid _PSD data\n");
        result = -EFAULT;
        goto end;
    }

    if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {
        printk(KERN_ERR PREFIX "Unknown _PSD:num_entries\n");
        result = -EFAULT;
        goto end;
    }

    if (pdomain->revision != ACPI_PSD_REV0_REVISION) {
        printk(KERN_ERR PREFIX "Unknown _PSD:revision\n");
        result = -EFAULT;
        goto end;
    }

    if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
        pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
        pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
        printk(KERN_ERR PREFIX "Invalid _PSD:coord_type\n");
        result = -EFAULT;
        goto end;
    }
end:
    kfree(buffer.pointer);
    return result;
}

int acpi_processor_preregister_performance(
        struct acpi_processor_performance __percpu *performance)
{
    int count, count_target;
    int retval = 0;
    unsigned int i, j;
    cpumask_var_t covered_cpus;
    struct acpi_processor *pr;
    struct acpi_psd_package *pdomain;
    struct acpi_processor *match_pr;
    struct acpi_psd_package *match_pdomain;

    if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
        return -ENOMEM;

    mutex_lock(&performance_mutex);

    /*
     * Check if another driver has already registered, and abort before
     * changing pr->performance if it has. Check input data as well.
     */
    for_each_possible_cpu(i) {
        pr = per_cpu(processors, i);
        if (!pr) {
            /* Look only at processors in ACPI namespace */
            continue;
        }

        if (pr->performance) {
            retval = -EBUSY;
            goto err_out;
        }

        if (!performance || !per_cpu_ptr(performance, i)) {
            retval = -EINVAL;
            goto err_out;
        }
    }

    /* Call _PSD for all CPUs */
    for_each_possible_cpu(i) {
        pr = per_cpu(processors, i);
        if (!pr)
            continue;

        pr->performance = per_cpu_ptr(performance, i);
        cpumask_set_cpu(i, pr->performance->shared_cpu_map);
        if (acpi_processor_get_psd(pr)) {
            retval = -EINVAL;
            continue;
        }
    }
    if (retval)
        goto err_ret;

    /*
     * Now that we have _PSD data from all CPUs, lets setup P-state 
     * domain info.
     */
    for_each_possible_cpu(i) {
        pr = per_cpu(processors, i);
        if (!pr)
            continue;

        if (cpumask_test_cpu(i, covered_cpus))
            continue;

        pdomain = &(pr->performance->domain_info);
        cpumask_set_cpu(i, pr->performance->shared_cpu_map);
        cpumask_set_cpu(i, covered_cpus);
        if (pdomain->num_processors <= 1)
            continue;

        /* Validate the Domain info */
        count_target = pdomain->num_processors;
        count = 1;
        if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
            pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
        else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
            pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW;
        else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
            pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY;

        for_each_possible_cpu(j) {
            if (i == j)
                continue;

            match_pr = per_cpu(processors, j);
            if (!match_pr)
                continue;

            match_pdomain = &(match_pr->performance->domain_info);
            if (match_pdomain->domain != pdomain->domain)
                continue;

            /* Here i and j are in the same domain */

            if (match_pdomain->num_processors != count_target) {
                retval = -EINVAL;
                goto err_ret;
            }

            if (pdomain->coord_type != match_pdomain->coord_type) {
                retval = -EINVAL;
                goto err_ret;
            }

            cpumask_set_cpu(j, covered_cpus);
            cpumask_set_cpu(j, pr->performance->shared_cpu_map);
            count++;
        }

        for_each_possible_cpu(j) {
            if (i == j)
                continue;

            match_pr = per_cpu(processors, j);
            if (!match_pr)
                continue;

            match_pdomain = &(match_pr->performance->domain_info);
            if (match_pdomain->domain != pdomain->domain)
                continue;

            match_pr->performance->shared_type = 
                    pr->performance->shared_type;
            cpumask_copy(match_pr->performance->shared_cpu_map,
                     pr->performance->shared_cpu_map);
        }
    }

err_ret:
    for_each_possible_cpu(i) {
        pr = per_cpu(processors, i);
        if (!pr || !pr->performance)
            continue;

        /* Assume no coordination on any error parsing domain info */
        if (retval) {
            cpumask_clear(pr->performance->shared_cpu_map);
            cpumask_set_cpu(i, pr->performance->shared_cpu_map);
            pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL;
        }
        pr->performance = NULL; /* Will be set for real in register */
    }

err_out:
    mutex_unlock(&performance_mutex);
    free_cpumask_var(covered_cpus);
    return retval;
}
EXPORT_SYMBOL(acpi_processor_preregister_performance);

int
acpi_processor_register_performance(struct acpi_processor_performance
                    *performance, unsigned int cpu)
{
    struct acpi_processor *pr;

    if (!(acpi_processor_ppc_status & PPC_REGISTERED))
        return -EINVAL;

    mutex_lock(&performance_mutex);

    pr = per_cpu(processors, cpu);
    if (!pr) {
        mutex_unlock(&performance_mutex);
        return -ENODEV;
    }

    if (pr->performance) {
        mutex_unlock(&performance_mutex);
        return -EBUSY;
    }

    WARN_ON(!performance);

    pr->performance = performance;

    if (acpi_processor_get_performance_info(pr)) {
        pr->performance = NULL;
        mutex_unlock(&performance_mutex);
        return -EIO;
    }

    mutex_unlock(&performance_mutex);
    return 0;
}

EXPORT_SYMBOL(acpi_processor_register_performance);

void
acpi_processor_unregister_performance(struct acpi_processor_performance
                      *performance, unsigned int cpu)
{
    struct acpi_processor *pr;

    mutex_lock(&performance_mutex);

    pr = per_cpu(processors, cpu);
    if (!pr) {
        mutex_unlock(&performance_mutex);
        return;
    }

    if (pr->performance)
        kfree(pr->performance->states);
    pr->performance = NULL;

    mutex_unlock(&performance_mutex);

    return;
}

EXPORT_SYMBOL(acpi_processor_unregister_performance);