1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  EFI application ACPI tables support
4  *
5  *  Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
6  */
7 
8 #include <common.h>
9 #include <efi_loader.h>
10 #include <log.h>
11 #include <mapmem.h>
12 #include <acpi/acpi_table.h>
13 
14 static const efi_guid_t acpi_guid = EFI_ACPI_TABLE_GUID;
15 
16 /*
17  * Install the ACPI table as a configuration table.
18  *
19  * Return:	status code
20  */
efi_acpi_register(void)21 efi_status_t efi_acpi_register(void)
22 {
23 	/* Map within the low 32 bits, to allow for 32bit ACPI tables */
24 	u64 acpi = U32_MAX;
25 	efi_status_t ret;
26 	ulong addr;
27 
28 	/* Reserve 64kiB page for ACPI */
29 	ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
30 				 EFI_ACPI_RECLAIM_MEMORY, 16, &acpi);
31 	if (ret != EFI_SUCCESS)
32 		return ret;
33 
34 	/*
35 	 * Generate ACPI tables - we know that efi_allocate_pages() returns
36 	 * a 4k-aligned address, so it is safe to assume that
37 	 * write_acpi_tables() will write the table at that address.
38 	 */
39 	addr = map_to_sysmem((void *)(ulong)acpi);
40 	write_acpi_tables(addr);
41 
42 	/* And expose them to our EFI payload */
43 	return efi_install_configuration_table(&acpi_guid,
44 					       (void *)(uintptr_t)acpi);
45 }
46