efi_loader: Install ACPI configuration tables

ACPI tables can be passed via EFI configuration table to an EFI
application. This is only supported on x86 so far.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

2 files changed, 43 insertions, 0 deletions

diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index c6046e36d2..d6402c4615 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -22,4 +22,5 @@ obj-$(CONFIG_LCD) += efi_gop.o
 obj-$(CONFIG_DM_VIDEO) += efi_gop.o
 obj-$(CONFIG_PARTITIONS) += efi_disk.o
 obj-$(CONFIG_NET) += efi_net.o
+obj-$(CONFIG_GENERATE_ACPI_TABLE) += efi_acpi.o
 obj-$(CONFIG_GENERATE_SMBIOS_TABLE) += efi_smbios.o
diff --git a/lib/efi_loader/efi_acpi.c b/lib/efi_loader/efi_acpi.c
new file mode 100644
index 0000000000..a4e5e53d15
--- /dev/null
+++ b/lib/efi_loader/efi_acpi.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  EFI application ACPI tables support
+ *
+ *  Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#include <common.h>
+#include <efi_loader.h>
+#include <asm/acpi_table.h>
+
+static const efi_guid_t acpi_guid = EFI_ACPI_TABLE_GUID;
+
+/*
+ * Install the ACPI table as a configuration table.
+ *
+ * @return	status code
+ */
+efi_status_t efi_acpi_register(void)
+{
+	/* Map within the low 32 bits, to allow for 32bit ACPI tables */
+	u64 acpi = U32_MAX;
+	efi_status_t ret;
+
+	/* Reserve 64kiB page for ACPI */
+	ret = efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS,
+				 EFI_RUNTIME_SERVICES_DATA, 16, &acpi);
+	if (ret != EFI_SUCCESS)
+		return ret;
+
+	/*
+	 * Generate ACPI tables - we know that efi_allocate_pages() returns
+	 * a 4k-aligned address, so it is safe to assume that
+	 * write_acpi_tables() will write the table at that address.
+	 */
+	assert(!(acpi & 0xf));
+	write_acpi_tables(acpi);
+
+	/* And expose them to our EFI payload */
+	return efi_install_configuration_table(&acpi_guid,
+					       (void *)(uintptr_t)acpi);
+}