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authorBhupesh Sharma <bhsharma@redhat.com>2017-04-04 17:02:40 +0100
committerIngo Molnar <mingo@kernel.org>2017-04-05 12:27:24 +0200
commit75def552bb1e0d39918df31b86f7d09e754ea0fc (patch)
tree36d2c1b0325ca0d846ef63ffbd689fffe5825a82 /drivers/firmware
parent24d7c494ce46d5bb6c8fd03e88a48ae249ec1492 (diff)
downloadlinux-75def552bb1e0d39918df31b86f7d09e754ea0fc.tar.bz2
x86/efi/bgrt: Move efi-bgrt handling out of arch/x86
Now with open-source boot firmware (EDK2) supporting ACPI BGRT table addition even for architectures like AARCH64, it makes sense to move out the 'efi-bgrt.c' file and supporting infrastructure from 'arch/x86' directory and house it inside 'drivers/firmware/efi', so that this common code can be used across architectures. Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20170404160245.27812-7-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efi/Makefile1
-rw-r--r--drivers/firmware/efi/efi-bgrt.c84
2 files changed, 85 insertions, 0 deletions
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index ad67342313ed..0329d319d89a 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -9,6 +9,7 @@
#
KASAN_SANITIZE_runtime-wrappers.o := n
+obj-$(CONFIG_ACPI_BGRT) += efi-bgrt.o
obj-$(CONFIG_EFI) += efi.o vars.o reboot.o memattr.o
obj-$(CONFIG_EFI) += capsule.o memmap.o
obj-$(CONFIG_EFI_VARS) += efivars.o
diff --git a/drivers/firmware/efi/efi-bgrt.c b/drivers/firmware/efi/efi-bgrt.c
new file mode 100644
index 000000000000..04ca8764f0c0
--- /dev/null
+++ b/drivers/firmware/efi/efi-bgrt.c
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2012 Intel Corporation
+ * Author: Josh Triplett <josh@joshtriplett.org>
+ *
+ * Based on the bgrt driver:
+ * Copyright 2012 Red Hat, Inc <mjg@redhat.com>
+ * Author: Matthew Garrett
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+#include <linux/efi.h>
+#include <linux/efi-bgrt.h>
+
+struct acpi_table_bgrt bgrt_tab;
+size_t __initdata bgrt_image_size;
+
+struct bmp_header {
+ u16 id;
+ u32 size;
+} __packed;
+
+void __init efi_bgrt_init(struct acpi_table_header *table)
+{
+ void *image;
+ struct bmp_header bmp_header;
+ struct acpi_table_bgrt *bgrt = &bgrt_tab;
+
+ if (acpi_disabled)
+ return;
+
+ if (table->length < sizeof(bgrt_tab)) {
+ pr_notice("Ignoring BGRT: invalid length %u (expected %zu)\n",
+ table->length, sizeof(bgrt_tab));
+ return;
+ }
+ *bgrt = *(struct acpi_table_bgrt *)table;
+ if (bgrt->version != 1) {
+ pr_notice("Ignoring BGRT: invalid version %u (expected 1)\n",
+ bgrt->version);
+ goto out;
+ }
+ if (bgrt->status & 0xfe) {
+ pr_notice("Ignoring BGRT: reserved status bits are non-zero %u\n",
+ bgrt->status);
+ goto out;
+ }
+ if (bgrt->image_type != 0) {
+ pr_notice("Ignoring BGRT: invalid image type %u (expected 0)\n",
+ bgrt->image_type);
+ goto out;
+ }
+ if (!bgrt->image_address) {
+ pr_notice("Ignoring BGRT: null image address\n");
+ goto out;
+ }
+
+ image = early_memremap(bgrt->image_address, sizeof(bmp_header));
+ if (!image) {
+ pr_notice("Ignoring BGRT: failed to map image header memory\n");
+ goto out;
+ }
+
+ memcpy(&bmp_header, image, sizeof(bmp_header));
+ early_memunmap(image, sizeof(bmp_header));
+ if (bmp_header.id != 0x4d42) {
+ pr_notice("Ignoring BGRT: Incorrect BMP magic number 0x%x (expected 0x4d42)\n",
+ bmp_header.id);
+ goto out;
+ }
+ bgrt_image_size = bmp_header.size;
+ efi_mem_reserve(bgrt->image_address, bgrt_image_size);
+
+ return;
+out:
+ memset(bgrt, 0, sizeof(bgrt_tab));
+}