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// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0/****************************************************************************** * * Module Name: evgpeinit - System GPE initialization and update * * Copyright (C) 2000 - 2019, Intel Corp. * *****************************************************************************/ACPI_MODULE_NAME("evgpeinit")/* 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); 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. */ if (acpi_gbl_FADT.gpe0_block_length && acpi_gbl_FADT.xgpe0_block.address) { /* GPE block 0 exists (has both length and address > 0) */