/*
 * Copyright (C) 2005 Intel Corporation
 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
 *
 *      Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
 *      - Added _PDC for platforms with Intel CPUs
 */

#define pr_fmt(fmt) "ACPI: " fmt

#include <linux/dmi.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <acpi/processor.h>

#include "internal.h"

#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_pdc");

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 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 *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)
                goto out;

        obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
        if (!obj) {
                kfree(obj_list);
                goto out;
        }

        buf = kmalloc(12, GFP_KERNEL);
        if (!buf) {
                kfree(obj);
                kfree(obj_list);
                goto out;
        }

        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;
out:
        pr_err("Memory allocation error\n");
        return NULL;
}

/*
 * _PDC is required for a BIOS-OS handshake for most of the newer
 * ACPI processor features.
 */
static acpi_status
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 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;
}

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

static struct dmi_system_id processor_idle_dmi_table[] __initdata = {
        {
        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 void __init processor_dmi_check(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);
}

void __init acpi_early_processor_set_pdc(void)
{
        processor_dmi_check();

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