evgpeinit.c

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/******************************************************************************
 *
 * Module Name: evgpeinit - System GPE initialization and update
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2012, Intel Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include "accommon.h"
#include "acevents.h"
#include "acnamesp.h"

#define _COMPONENT          ACPI_EVENTS
ACPI_MODULE_NAME("evgpeinit")
#if (!ACPI_REDUCED_HARDWARE)    /* Entire module */
/*
 * Note: History of _PRW support in ACPICA
 *
 * Originally (2000 - 2010), the GPE initialization code performed a walk of
 * the entire namespace to execute the _PRW methods and detect all GPEs
 * capable of waking the system.
 *
 * As of 10/2010, the _PRW method execution has been removed since it is
 * actually unnecessary. The host OS must in fact execute all _PRW methods
 * in order to identify the device/power-resource dependencies. We now put
 * the onus on the host OS to identify the wake GPEs as part of this process
 * and to inform ACPICA of these GPEs via the acpi_setup_gpe_for_wake interface. This
 * not only reduces the complexity of the ACPICA initialization code, but in
 * some cases (on systems with very large namespaces) it should reduce the
 * kernel boot time as well.
 */

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_gpe_initialize
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Initialize the GPE data structures and the FADT GPE 0/1 blocks
 *
 ******************************************************************************/
acpi_status acpi_ev_gpe_initialize(void)
{
    u32 register_count0 = 0;
    u32 register_count1 = 0;
    u32 gpe_number_max = 0;
    acpi_status status;

    ACPI_FUNCTION_TRACE(ev_gpe_initialize);

    status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }

    /*
     * Initialize the GPE Block(s) defined in the FADT
     *
     * Why the GPE register block lengths are divided by 2:  From the ACPI
     * Spec, section "General-Purpose Event Registers", we have:
     *
     * "Each register block contains two registers of equal length
     *  GPEx_STS and GPEx_EN (where x is 0 or 1). The length of the
     *  GPE0_STS and GPE0_EN registers is equal to half the GPE0_LEN
     *  The length of the GPE1_STS and GPE1_EN registers is equal to
     *  half the GPE1_LEN. If a generic register block is not supported
     *  then its respective block pointer and block length values in the
     *  FADT table contain zeros. The GPE0_LEN and GPE1_LEN do not need
     *  to be the same size."
     */

    /*
     * Determine the maximum GPE number for this machine.
     *
     * Note: both GPE0 and GPE1 are optional, and either can exist without
     * the other.
     *
     * If EITHER the register length OR the block address are zero, then that
     * particular block is not supported.
     */
    if (acpi_gbl_FADT.gpe0_block_length &&
        acpi_gbl_FADT.xgpe0_block.address) {

        /* GPE block 0 exists (has both length and address > 0) */

        register_count0 = (u16)(acpi_gbl_FADT.gpe0_block_length / 2);

        gpe_number_max =
            (register_count0 * ACPI_GPE_REGISTER_WIDTH) - 1;

        /* Install GPE Block 0 */

        status = acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
                          &acpi_gbl_FADT.xgpe0_block,
                          register_count0, 0,
                          acpi_gbl_FADT.sci_interrupt,
                          &acpi_gbl_gpe_fadt_blocks[0]);

        if (ACPI_FAILURE(status)) {
            ACPI_EXCEPTION((AE_INFO, status,
                    "Could not create GPE Block 0"));
        }
    }

    if (acpi_gbl_FADT.gpe1_block_length &&
        acpi_gbl_FADT.xgpe1_block.address) {

        /* GPE block 1 exists (has both length and address > 0) */

        register_count1 = (u16)(acpi_gbl_FADT.gpe1_block_length / 2);

        /* Check for GPE0/GPE1 overlap (if both banks exist) */

        if ((register_count0) &&
            (gpe_number_max >= acpi_gbl_FADT.gpe1_base)) {
            ACPI_ERROR((AE_INFO,
                    "GPE0 block (GPE 0 to %u) overlaps the GPE1 block "
                    "(GPE %u to %u) - Ignoring GPE1",
                    gpe_number_max, acpi_gbl_FADT.gpe1_base,
                    acpi_gbl_FADT.gpe1_base +
                    ((register_count1 *
                      ACPI_GPE_REGISTER_WIDTH) - 1)));

            /* Ignore GPE1 block by setting the register count to zero */

            register_count1 = 0;
        } else {
            /* Install GPE Block 1 */

            status =
                acpi_ev_create_gpe_block(acpi_gbl_fadt_gpe_device,
                             &acpi_gbl_FADT.xgpe1_block,
                             register_count1,
                             acpi_gbl_FADT.gpe1_base,
                             acpi_gbl_FADT.
                             sci_interrupt,
                             &acpi_gbl_gpe_fadt_blocks
                             [1]);

            if (ACPI_FAILURE(status)) {
                ACPI_EXCEPTION((AE_INFO, status,
                        "Could not create GPE Block 1"));
            }

            /*
             * GPE0 and GPE1 do not have to be contiguous in the GPE number
             * space. However, GPE0 always starts at GPE number zero.
             */
            gpe_number_max = acpi_gbl_FADT.gpe1_base +
                ((register_count1 * ACPI_GPE_REGISTER_WIDTH) - 1);
        }
    }

    /* Exit if there are no GPE registers */

    if ((register_count0 + register_count1) == 0) {

        /* GPEs are not required by ACPI, this is OK */

        ACPI_DEBUG_PRINT((ACPI_DB_INIT,
                  "There are no GPE blocks defined in the FADT\n"));
        status = AE_OK;
        goto cleanup;
    }

    /* Check for Max GPE number out-of-range */

    if (gpe_number_max > ACPI_GPE_MAX) {
        ACPI_ERROR((AE_INFO,
                "Maximum GPE number from FADT is too large: 0x%X",
                gpe_number_max));
        status = AE_BAD_VALUE;
        goto cleanup;
    }

      cleanup:
    (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
    return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_update_gpes
 *
 * PARAMETERS:  table_owner_id      - ID of the newly-loaded ACPI table
 *
 * RETURN:      None
 *
 * DESCRIPTION: Check for new GPE methods (_Lxx/_Exx) made available as a
 *              result of a Load() or load_table() operation. If new GPE
 *              methods have been installed, register the new methods.
 *
 ******************************************************************************/

void acpi_ev_update_gpes(acpi_owner_id table_owner_id)
{
    struct acpi_gpe_xrupt_info *gpe_xrupt_info;
    struct acpi_gpe_block_info *gpe_block;
    struct acpi_gpe_walk_info walk_info;
    acpi_status status = AE_OK;

    /*
     * Find any _Lxx/_Exx GPE methods that have just been loaded.
     *
     * Any GPEs that correspond to new _Lxx/_Exx methods are immediately
     * enabled.
     *
     * Examine the namespace underneath each gpe_device within the
     * gpe_block lists.
     */
    status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
    if (ACPI_FAILURE(status)) {
        return;
    }

    walk_info.count = 0;
    walk_info.owner_id = table_owner_id;
    walk_info.execute_by_owner_id = TRUE;

    /* Walk the interrupt level descriptor list */

    gpe_xrupt_info = acpi_gbl_gpe_xrupt_list_head;
    while (gpe_xrupt_info) {

        /* Walk all Gpe Blocks attached to this interrupt level */

        gpe_block = gpe_xrupt_info->gpe_block_list_head;
        while (gpe_block) {
            walk_info.gpe_block = gpe_block;
            walk_info.gpe_device = gpe_block->node;

            status = acpi_ns_walk_namespace(ACPI_TYPE_METHOD,
                            walk_info.gpe_device,
                            ACPI_UINT32_MAX,
                            ACPI_NS_WALK_NO_UNLOCK,
                            acpi_ev_match_gpe_method,
                            NULL, &walk_info, NULL);
            if (ACPI_FAILURE(status)) {
                ACPI_EXCEPTION((AE_INFO, status,
                        "While decoding _Lxx/_Exx methods"));
            }

            gpe_block = gpe_block->next;
        }

        gpe_xrupt_info = gpe_xrupt_info->next;
    }

    if (walk_info.count) {
        ACPI_INFO((AE_INFO, "Enabled %u new GPEs", walk_info.count));
    }

    (void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
    return;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_match_gpe_method
 *
 * PARAMETERS:  Callback from walk_namespace
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Called from acpi_walk_namespace. Expects each object to be a
 *              control method under the _GPE portion of the namespace.
 *              Extract the name and GPE type from the object, saving this
 *              information for quick lookup during GPE dispatch. Allows a
 *              per-owner_id evaluation if execute_by_owner_id is TRUE in the
 *              walk_info parameter block.
 *
 *              The name of each GPE control method is of the form:
 *              "_Lxx" or "_Exx", where:
 *                  L      - means that the GPE is level triggered
 *                  E      - means that the GPE is edge triggered
 *                  xx     - is the GPE number [in HEX]
 *
 * If walk_info->execute_by_owner_id is TRUE, we only execute examine GPE methods
 * with that owner.
 *
 ******************************************************************************/

acpi_status
acpi_ev_match_gpe_method(acpi_handle obj_handle,
             u32 level, void *context, void **return_value)
{
    struct acpi_namespace_node *method_node =
        ACPI_CAST_PTR(struct acpi_namespace_node, obj_handle);
    struct acpi_gpe_walk_info *walk_info =
        ACPI_CAST_PTR(struct acpi_gpe_walk_info, context);
    struct acpi_gpe_event_info *gpe_event_info;
    u32 gpe_number;
    char name[ACPI_NAME_SIZE + 1];
    u8 type;

    ACPI_FUNCTION_TRACE(ev_match_gpe_method);

    /* Check if requested owner_id matches this owner_id */

    if ((walk_info->execute_by_owner_id) &&
        (method_node->owner_id != walk_info->owner_id)) {
        return_ACPI_STATUS(AE_OK);
    }

    /*
     * Match and decode the _Lxx and _Exx GPE method names
     *
     * 1) Extract the method name and null terminate it
     */
    ACPI_MOVE_32_TO_32(name, &method_node->name.integer);
    name[ACPI_NAME_SIZE] = 0;

    /* 2) Name must begin with an underscore */

    if (name[0] != '_') {
        return_ACPI_STATUS(AE_OK);  /* Ignore this method */
    }

    /*
     * 3) Edge/Level determination is based on the 2nd character
     *    of the method name
     */
    switch (name[1]) {
    case 'L':
        type = ACPI_GPE_LEVEL_TRIGGERED;
        break;

    case 'E':
        type = ACPI_GPE_EDGE_TRIGGERED;
        break;

    default:
        /* Unknown method type, just ignore it */

        ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
                  "Ignoring unknown GPE method type: %s "
                  "(name not of form _Lxx or _Exx)", name));
        return_ACPI_STATUS(AE_OK);
    }

    /* 4) The last two characters of the name are the hex GPE Number */

    gpe_number = ACPI_STRTOUL(&name[2], NULL, 16);
    if (gpe_number == ACPI_UINT32_MAX) {

        /* Conversion failed; invalid method, just ignore it */

        ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
                  "Could not extract GPE number from name: %s "
                  "(name is not of form _Lxx or _Exx)", name));
        return_ACPI_STATUS(AE_OK);
    }

    /* Ensure that we have a valid GPE number for this GPE block */

    gpe_event_info =
        acpi_ev_low_get_gpe_info(gpe_number, walk_info->gpe_block);
    if (!gpe_event_info) {
        /*
         * This gpe_number is not valid for this GPE block, just ignore it.
         * However, it may be valid for a different GPE block, since GPE0
         * and GPE1 methods both appear under \_GPE.
         */
        return_ACPI_STATUS(AE_OK);
    }

    if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
        ACPI_GPE_DISPATCH_HANDLER) {

        /* If there is already a handler, ignore this GPE method */

        return_ACPI_STATUS(AE_OK);
    }

    if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
        ACPI_GPE_DISPATCH_METHOD) {
        /*
         * If there is already a method, ignore this method. But check
         * for a type mismatch (if both the _Lxx AND _Exx exist)
         */
        if (type != (gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK)) {
            ACPI_ERROR((AE_INFO,
                    "For GPE 0x%.2X, found both _L%2.2X and _E%2.2X methods",
                    gpe_number, gpe_number, gpe_number));
        }
        return_ACPI_STATUS(AE_OK);
    }

    /* Disable the GPE in case it's been enabled already. */
    (void)acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);

    /*
     * Add the GPE information from above to the gpe_event_info block for
     * use during dispatch of this GPE.
     */
    gpe_event_info->flags &= ~(ACPI_GPE_DISPATCH_MASK);
    gpe_event_info->flags |= (u8)(type | ACPI_GPE_DISPATCH_METHOD);
    gpe_event_info->dispatch.method_node = method_node;

    ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
              "Registered GPE method %s as GPE number 0x%.2X\n",
              name, gpe_number));
    return_ACPI_STATUS(AE_OK);
}

#endif              /* !ACPI_REDUCED_HARDWARE */