processor_core.c

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/*
 * Copyright (C) 2005 Intel Corporation
 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
 *
 *  Alex Chiang <[email protected]>
 *  - Unified x86/ia64 implementations
 *  Venkatesh Pallipadi <[email protected]>
 *  - Added _PDC for platforms with Intel CPUs
 */
#include <linux/export.h>
#include <linux/dmi.h>
#include <linux/slab.h>

#include <acpi/acpi_drivers.h>
#include <acpi/processor.h>

#include "internal.h"

#define PREFIX          "ACPI: "
#define _COMPONENT      ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_core");

static int __init set_no_mwait(const struct dmi_system_id *id)
{
    printk(KERN_NOTICE PREFIX "%s detected - "
        "disabling mwait for CPU C-states\n", id->ident);
    boot_option_idle_override = IDLE_NOMWAIT;
    return 0;
}

static struct dmi_system_id __initdata processor_idle_dmi_table[] = {
    {
    set_no_mwait, "Extensa 5220", {
    DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
    DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
    DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
    DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
    {},
};

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))
        return 0;

    if (lapic->processor_id != acpi_id)
        return 0;

    *apic_id = lapic->id;
    return 1;
}

static int map_x2apic_id(struct acpi_subtable_header *entry,
             int device_declaration, u32 acpi_id, int *apic_id)
{
    struct acpi_madt_local_x2apic *apic =
        (struct acpi_madt_local_x2apic *)entry;

    if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
        return 0;

    if (device_declaration && (apic->uid == acpi_id)) {
        *apic_id = apic->local_apic_id;
        return 1;
    }

    return 0;
}

static int map_lsapic_id(struct acpi_subtable_header *entry,
        int device_declaration, u32 acpi_id, int *apic_id)
{
    struct acpi_madt_local_sapic *lsapic =
        (struct acpi_madt_local_sapic *)entry;

    if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
        return 0;

    if (device_declaration) {
        if ((entry->length < 16) || (lsapic->uid != acpi_id))
            return 0;
    } else if (lsapic->processor_id != acpi_id)
        return 0;

    *apic_id = (lsapic->id << 8) | lsapic->eid;
    return 1;
}

static int map_madt_entry(int type, u32 acpi_id)
{
    unsigned long madt_end, entry;
    static struct acpi_table_madt *madt;
    static int read_madt;
    int apic_id = -1;

    if (!read_madt) {
        if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
                    (struct acpi_table_header **)&madt)))
            madt = NULL;
        read_madt++;
    }

    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_X2APIC) {
            if (map_x2apic_id(header, type, acpi_id, &apic_id))
                break;
        } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
            if (map_lsapic_id(header, type, acpi_id, &apic_id))
                break;
        }
        entry += header->length;
    }
    return apic_id;
}

static int map_mat_entry(acpi_handle handle, int type, 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, type, acpi_id, &apic_id);
    }

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

int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
{
#ifdef CONFIG_SMP
    int i;
#endif
    int apic_id = -1;

    apic_id = map_mat_entry(handle, type, acpi_id);
    if (apic_id == -1)
        apic_id = map_madt_entry(type, acpi_id);
    if (apic_id == -1) {
        /*
         * On UP processor, there is no _MAT or MADT table.
         * So above apic_id is always set to -1.
         *
         * BIOS may define multiple CPU handles even for UP processor.
         * For example,
         *
         * Scope (_PR)
                 * {
         *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
         *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
         *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
         *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
         * }
         *
         * Ignores apic_id and always returns 0 for the processor
         * handle with acpi id 0 if nr_cpu_ids is 1.
         * This should be the case if SMP tables are not found.
         * Return -1 for other CPU's handle.
         */
        if (nr_cpu_ids <= 1 && acpi_id == 0)
            return acpi_id;
        else
            return apic_id;
    }

#ifdef CONFIG_SMP
    for_each_possible_cpu(i) {
        if (cpu_physical_id(i) == apic_id)
            return i;
    }
#else
    /* In UP kernel, only processor 0 is valid */
    if (apic_id == 0)
        return apic_id;
#endif
    return -1;
}
EXPORT_SYMBOL_GPL(acpi_get_cpuid);

static bool __init processor_physically_present(acpi_handle handle)
{
    int cpuid, type;
    u32 acpi_id;
    acpi_status status;
    acpi_object_type acpi_type;
    unsigned long long tmp;
    union acpi_object object = { 0 };
    struct acpi_buffer buffer = { sizeof(union acpi_object), &object };

    status = acpi_get_type(handle, &acpi_type);
    if (ACPI_FAILURE(status))
        return false;

    switch (acpi_type) {
    case ACPI_TYPE_PROCESSOR:
        status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
        if (ACPI_FAILURE(status))
            return false;
        acpi_id = object.processor.proc_id;
        break;
    case ACPI_TYPE_DEVICE:
        status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
        if (ACPI_FAILURE(status))
            return false;
        acpi_id = tmp;
        break;
    default:
        return false;
    }

    type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
    cpuid = acpi_get_cpuid(handle, type, acpi_id);

    if (cpuid == -1)
        return false;

    return true;
}

static void __cpuinit acpi_set_pdc_bits(u32 *buf)
{
    buf[0] = ACPI_PDC_REVISION_ID;
    buf[1] = 1;

    /* Enable coordination with firmware's _TSD info */
    buf[2] = ACPI_PDC_SMP_T_SWCOORD;

    /* Twiddle arch-specific bits needed for _PDC */
    arch_acpi_set_pdc_bits(buf);
}

static struct acpi_object_list *__cpuinit acpi_processor_alloc_pdc(void)
{
    struct acpi_object_list *obj_list;
    union acpi_object *obj;
    u32 *buf;

    /* allocate and initialize pdc. It will be used later. */
    obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
    if (!obj_list) {
        printk(KERN_ERR "Memory allocation error\n");
        return NULL;
    }

    obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
    if (!obj) {
        printk(KERN_ERR "Memory allocation error\n");
        kfree(obj_list);
        return NULL;
    }

    buf = kmalloc(12, GFP_KERNEL);
    if (!buf) {
        printk(KERN_ERR "Memory allocation error\n");
        kfree(obj);
        kfree(obj_list);
        return NULL;
    }

    acpi_set_pdc_bits(buf);

    obj->type = ACPI_TYPE_BUFFER;
    obj->buffer.length = 12;
    obj->buffer.pointer = (u8 *) buf;
    obj_list->count = 1;
    obj_list->pointer = obj;

    return obj_list;
}

/*
 * _PDC is required for a BIOS-OS handshake for most of the newer
 * ACPI processor features.
 */
static int __cpuinit
acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
{
    acpi_status status = AE_OK;

    if (boot_option_idle_override == IDLE_NOMWAIT) {
        /*
         * If mwait is disabled for CPU C-states, the C2C3_FFH access
         * mode will be disabled in the parameter of _PDC object.
         * Of course C1_FFH access mode will also be disabled.
         */
        union acpi_object *obj;
        u32 *buffer = NULL;

        obj = pdc_in->pointer;
        buffer = (u32 *)(obj->buffer.pointer);
        buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);

    }
    status = acpi_evaluate_object(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;
}

void __cpuinit acpi_processor_set_pdc(acpi_handle handle)
{
    struct acpi_object_list *obj_list;

    if (arch_has_acpi_pdc() == false)
        return;

    obj_list = acpi_processor_alloc_pdc();
    if (!obj_list)
        return;

    acpi_processor_eval_pdc(handle, obj_list);

    kfree(obj_list->pointer->buffer.pointer);
    kfree(obj_list->pointer);
    kfree(obj_list);
}

static acpi_status __init
early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
{
    if (processor_physically_present(handle) == false)
        return AE_OK;

    acpi_processor_set_pdc(handle);
    return AE_OK;
}

void __init acpi_early_processor_set_pdc(void)
{
    /*
     * Check whether the system is DMI table. If yes, OSPM
     * should not use mwait for CPU-states.
     */
    dmi_check_system(processor_idle_dmi_table);

    acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
                ACPI_UINT32_MAX,
                early_init_pdc, NULL, NULL, NULL);
    acpi_get_devices("ACPI0007", early_init_pdc, NULL, NULL);
}