/*******************************************************************************
 *
 * FUNCTION:    acpi_initialize_objects
 *
 * PARAMETERS:  Flags           - Init/enable Options
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Completes namespace initialization by initializing device
 *              objects and executing AML code for Regions, buffers, etc.
 *
 ******************************************************************************/
acpi_status acpi_initialize_objects(u32 flags)
{
	acpi_status status = AE_OK;

	ACPI_FUNCTION_TRACE(acpi_initialize_objects);

	/*
	 * Run all _REG methods
	 *
	 * Note: Any objects accessed by the _REG methods will be automatically
	 * initialized, even if they contain executable AML (see the call to
	 * acpi_ns_initialize_objects below).
	 */
	if (!(flags & ACPI_NO_ADDRESS_SPACE_INIT)) {
		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
				  "[Init] Executing _REG OpRegion methods\n"));

		status = acpi_ev_initialize_op_regions();
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/*
	 * Execute any module-level code that was detected during the table load
	 * phase. Although illegal since ACPI 2.0, there are many machines that
	 * contain this type of code. Each block of detected executable AML code
	 * outside of any control method is wrapped with a temporary control
	 * method object and placed on a global list. The methods on this list
	 * are executed below.
	 */
	acpi_ns_exec_module_code_list();

	/*
	 * Initialize the objects that remain uninitialized. This runs the
	 * executable AML that may be part of the declaration of these objects:
	 * operation_regions, buffer_fields, Buffers, and Packages.
	 */
	if (!(flags & ACPI_NO_OBJECT_INIT)) {
		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
				  "[Init] Completing Initialization of ACPI Objects\n"));

		status = acpi_ns_initialize_objects();
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/*
	 * Initialize all device objects in the namespace. This runs the device
	 * _STA and _INI methods.
	 */
	if (!(flags & ACPI_NO_DEVICE_INIT)) {
		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
				  "[Init] Initializing ACPI Devices\n"));

		status = acpi_ns_initialize_devices();
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/*
	 * Complete the GPE initialization for the GPE blocks defined in the FADT
	 * (GPE block 0 and 1).
	 *
	 * Note1: This is where the _PRW methods are executed for the GPEs. These
	 * methods can only be executed after the SCI and Global Lock handlers are
	 * installed and initialized.
	 *
	 * Note2: Currently, there seems to be no need to run the _REG methods
	 * before execution of the _PRW methods and enabling of the GPEs.
	 */
	if (!(flags & ACPI_NO_EVENT_INIT)) {
		status = acpi_ev_install_fadt_gpes();
		if (ACPI_FAILURE(status))
			return (status);
	}

	/*
	 * Empty the caches (delete the cached objects) on the assumption that
	 * the table load filled them up more than they will be at runtime --
	 * thus wasting non-paged memory.
	 */
	status = acpi_purge_cached_objects();

	acpi_gbl_startup_flags |= ACPI_INITIALIZED_OK;
	return_ACPI_STATUS(status);
}
/**ltl
 * 功能:使能ACPI子系统
 * 参数:
 * 返回值:
 * 说明:
 */
acpi_status acpi_enable_subsystem(u32 flags)
{
	acpi_status status = AE_OK;

	ACPI_FUNCTION_TRACE(acpi_enable_subsystem);

	/*
	 * We must initialize the hardware before we can enable ACPI.
	 * The values from the FADT are validated here.
	 */
	if (!(flags & ACPI_NO_HARDWARE_INIT)) { /* 初始化ACPI硬件模块 */
		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
				  "[Init] Initializing ACPI hardware\n"));

		status = acpi_hw_initialize();
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/* Enable ACPI mode */

	if (!(flags & ACPI_NO_ACPI_ENABLE)) { /* 使能ACPI硬件模块 */
		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
				  "[Init] Going into ACPI mode\n"));
		/* 返回值模式 */
		acpi_gbl_original_mode = acpi_hw_get_mode();
		/* 设置ACPI模式 */
		status = acpi_enable();
		if (ACPI_FAILURE(status)) {
			ACPI_WARNING((AE_INFO, "AcpiEnable failed"));
			return_ACPI_STATUS(status);
		}
	}

	/*
	 * Install the default op_region handlers. These are installed unless
	 * other handlers have already been installed via the
	 * install_address_space_handler interface.
	 */
	if (!(flags & ACPI_NO_ADDRESS_SPACE_INIT)) {
		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
				  "[Init] Installing default address space handlers\n"));
		/* 为四个地址空间设置默认处理句柄 */
		status = acpi_ev_install_region_handlers();
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/*
	 * Initialize ACPI Event handling (Fixed and General Purpose)
	 *
	 * Note1: We must have the hardware and events initialized before we can
	 * execute any control methods safely. Any control method can require
	 * ACPI hardware support, so the hardware must be fully initialized before
	 * any method execution!
	 *
	 * Note2: Fixed events are initialized and enabled here. GPEs are
	 * initialized, but cannot be enabled until after the hardware is
	 * completely initialized (SCI and global_lock activated)
	 */
	if (!(flags & ACPI_NO_EVENT_INIT)) {
		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
				  "[Init] Initializing ACPI events\n"));
		/* 初始化ACPI事件(设置相关寄存器) */
		status = acpi_ev_initialize_events();
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/*
	 * Install the SCI handler and Global Lock handler. This completes the
	 * hardware initialization.
	 */
	if (!(flags & ACPI_NO_HANDLER_INIT)) {
		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
				  "[Init] Installing SCI/GL handlers\n"));
		/* 为ACPI模块安装中断处理函数 */
		status = acpi_ev_install_xrupt_handlers();
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/*
	 * Complete the GPE initialization for the GPE blocks defined in the FADT
	 * (GPE block 0 and 1).
	 *
	 * Note1: This is where the _PRW methods are executed for the GPEs. These
	 * methods can only be executed after the SCI and Global Lock handlers are
	 * installed and initialized.
	 *
	 * Note2: Currently, there seems to be no need to run the _REG methods
	 * before execution of the _PRW methods and enabling of the GPEs.
	 */
	if (!(flags & ACPI_NO_EVENT_INIT)) {
		status = acpi_ev_install_fadt_gpes(); /* 使能通用寄存器 */
		if (ACPI_FAILURE(status)) {
			return (status);
		}
	}

	return_ACPI_STATUS(status);
}