// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: evgpeinit - System GPE initialization and update
 *
 * Copyright (C) 2000 - 2025, Intel Corp.
 *
 *****************************************************************************/

#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.
 */

#ifdef ACPI_GPE_USE_LOGICAL_ADDRESSES
#define ACPI_FADT_GPE_BLOCK_ADDRESS(N)  \
        acpi_gbl_FADT.xgpe##N##_block.space_id == \
                                        ACPI_ADR_SPACE_SYSTEM_MEMORY ? \
                (u64)acpi_gbl_xgpe##N##_block_logical_address : \
                acpi_gbl_FADT.xgpe##N##_block.address
#else
#define ACPI_FADT_GPE_BLOCK_ADDRESS(N)  acpi_gbl_FADT.xgpe##N##_block.address
#endif          /* ACPI_GPE_USE_LOGICAL_ADDRESSES */

/*******************************************************************************
 *
 * 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;
        u64 address;

        ACPI_FUNCTION_TRACE(ev_gpe_initialize);

        ACPI_DEBUG_PRINT_RAW((ACPI_DB_INIT,
                              "Initializing General Purpose Events (GPEs):\n"));

        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.
         */
        address = ACPI_FADT_GPE_BLOCK_ADDRESS(0);

        if (acpi_gbl_FADT.gpe0_block_length && 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,
                                                  address,
                                                  acpi_gbl_FADT.xgpe0_block.
                                                  space_id, 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"));
                }
        }

        address = ACPI_FADT_GPE_BLOCK_ADDRESS(1);

        if (acpi_gbl_FADT.gpe1_block_length && 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,
                                                     address,
                                                     acpi_gbl_FADT.xgpe1_block.
                                                     space_id, 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.
                         */
                }
        }

        /* 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"));
                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(("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;
        acpi_status status;
        u32 gpe_number;
        u8 temp_gpe_number;
        char name[ACPI_NAMESEG_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_NAMESEG_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 */

        status = acpi_ut_ascii_to_hex_byte(&name[2], &temp_gpe_number);
        if (ACPI_FAILURE(status)) {

                /* 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_number = (u32)temp_gpe_number;
        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 ((ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
             ACPI_GPE_DISPATCH_HANDLER) ||
            (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
             ACPI_GPE_DISPATCH_RAW_HANDLER)) {

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

                return_ACPI_STATUS(AE_OK);
        }

        if (ACPI_GPE_DISPATCH_TYPE(gpe_event_info->flags) ==
            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;
        walk_info->count++;

        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 */