From 86df34d42b05f574854f19c96142d8e5d30f5d8d Mon Sep 17 00:00:00 2001
From: Bin Meng <bmeng.cn@gmail.com>
Date: Wed, 27 Jun 2018 20:38:03 -0700
Subject: [PATCH] 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>
---
 cmd/bootefi.c             |  5 +++++
 include/efi_api.h         |  4 ++++
 include/efi_loader.h      |  8 ++++++++
 lib/efi_loader/Makefile   |  1 +
 lib/efi_loader/efi_acpi.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 60 insertions(+)
 create mode 100644 lib/efi_loader/efi_acpi.c

diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index f55a40d..cd755b6 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -61,6 +61,11 @@ efi_status_t efi_init_obj_list(void)
 	if (ret != EFI_SUCCESS)
 		goto out;
 #endif
+#ifdef CONFIG_GENERATE_ACPI_TABLE
+	ret = efi_acpi_register();
+	if (ret != EFI_SUCCESS)
+		goto out;
+#endif
 #ifdef CONFIG_GENERATE_SMBIOS_TABLE
 	ret = efi_smbios_register();
 	if (ret != EFI_SUCCESS)
diff --git a/include/efi_api.h b/include/efi_api.h
index 094be6e..0c3dd3c 100644
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -282,6 +282,10 @@ struct efi_runtime_services {
 	EFI_GUID(0xb1b621d5, 0xf19c, 0x41a5, \
 		 0x83, 0x0b, 0xd9, 0x15, 0x2c, 0x69, 0xaa, 0xe0)
 
+#define EFI_ACPI_TABLE_GUID \
+	EFI_GUID(0x8868e871, 0xe4f1, 0x11d3, \
+		 0xbc, 0x22, 0x00, 0x80, 0xc7, 0x3c, 0x88, 0x81)
+
 #define SMBIOS_TABLE_GUID \
 	EFI_GUID(0xeb9d2d31, 0x2d88, 0x11d3,  \
 		 0x9a, 0x16, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
diff --git a/include/efi_loader.h b/include/efi_loader.h
index c66252a..d837e7b 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -215,6 +215,14 @@ efi_status_t efi_net_register(void);
 efi_status_t efi_watchdog_register(void);
 /* Called by bootefi to make SMBIOS tables available */
 /**
+ * efi_acpi_register() - write out ACPI tables
+ *
+ * Called by bootefi to make ACPI tables available
+ *
+ * @return 0 if OK, -ENOMEM if no memory is available for the tables
+ */
+efi_status_t efi_acpi_register(void);
+/**
  * efi_smbios_register() - write out SMBIOS tables
  *
  * Called by bootefi to make SMBIOS tables available
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index c6046e3..d6402c4 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 0000000..a4e5e53
--- /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);
+}