xref: /openbmc/u-boot/lib/efi_loader/efi_acpi.c (revision ac378bb05fa3cac3197085431f577e0dbddd4b4a)
1*86df34d4SBin Meng // SPDX-License-Identifier: GPL-2.0+
2*86df34d4SBin Meng /*
3*86df34d4SBin Meng  *  EFI application ACPI tables support
4*86df34d4SBin Meng  *
5*86df34d4SBin Meng  *  Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
6*86df34d4SBin Meng  */
7*86df34d4SBin Meng 
8*86df34d4SBin Meng #include <common.h>
9*86df34d4SBin Meng #include <efi_loader.h>
10*86df34d4SBin Meng #include <asm/acpi_table.h>
11*86df34d4SBin Meng 
12*86df34d4SBin Meng static const efi_guid_t acpi_guid = EFI_ACPI_TABLE_GUID;
13*86df34d4SBin Meng 
14*86df34d4SBin Meng /*
15*86df34d4SBin Meng  * Install the ACPI table as a configuration table.
16*86df34d4SBin Meng  *
17*86df34d4SBin Meng  * @return	status code
18*86df34d4SBin Meng  */
efi_acpi_register(void)19*86df34d4SBin Meng efi_status_t efi_acpi_register(void)
20*86df34d4SBin Meng {
21*86df34d4SBin Meng 	/* Map within the low 32 bits, to allow for 32bit ACPI tables */
22*86df34d4SBin Meng 	u64 acpi = U32_MAX;
23*86df34d4SBin Meng 	efi_status_t ret;
24*86df34d4SBin Meng 
25*86df34d4SBin Meng 	/* Reserve 64kiB page for ACPI */
26*86df34d4SBin Meng 	ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
27*86df34d4SBin Meng 				 EFI_RUNTIME_SERVICES_DATA, 16, &acpi);
28*86df34d4SBin Meng 	if (ret != EFI_SUCCESS)
29*86df34d4SBin Meng 		return ret;
30*86df34d4SBin Meng 
31*86df34d4SBin Meng 	/*
32*86df34d4SBin Meng 	 * Generate ACPI tables - we know that efi_allocate_pages() returns
33*86df34d4SBin Meng 	 * a 4k-aligned address, so it is safe to assume that
34*86df34d4SBin Meng 	 * write_acpi_tables() will write the table at that address.
35*86df34d4SBin Meng 	 */
36*86df34d4SBin Meng 	assert(!(acpi & 0xf));
37*86df34d4SBin Meng 	write_acpi_tables(acpi);
38*86df34d4SBin Meng 
39*86df34d4SBin Meng 	/* And expose them to our EFI payload */
40*86df34d4SBin Meng 	return efi_install_configuration_table(&acpi_guid,
41*86df34d4SBin Meng 					       (void *)(uintptr_t)acpi);
42*86df34d4SBin Meng }
43