3 files changed, 83 insertions, 0 deletions

diff --git a/arch/x86/platform/efi/Makefile b/arch/x86/platform/efi/Makefile
index 73b8be0f3675..6db1cc4c7534 100644
--- a/arch/x86/platform/efi/Makefile
+++ b/arch/x86/platform/efi/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_EFI)               += efi.o efi_$(BITS).o efi_stub_$(BITS).o
+obj-$(CONFIG_ACPI_BGRT) += efi-bgrt.o
diff --git a/arch/x86/platform/efi/efi-bgrt.c b/arch/x86/platform/efi/efi-bgrt.c
new file mode 100644
index 000000000000..f6a0c1b8e518
--- /dev/null
+++ b/arch/x86/platform/efi/efi-bgrt.c
@@ -0,0 +1,76 @@
+/*
+ * 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.
+ */
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/efi.h>
+#include <linux/efi-bgrt.h>
+
+struct acpi_table_bgrt *bgrt_tab;
+void *bgrt_image;
+size_t bgrt_image_size;
+
+struct bmp_header {
+        u16 id;
+        u32 size;
+} __packed;
+
+void efi_bgrt_init(void)
+{
+        acpi_status status;
+        void __iomem *image;
+        bool ioremapped = false;
+        struct bmp_header bmp_header;
+
+        if (acpi_disabled)
+                return;
+
+        status = acpi_get_table("BGRT", 0,
+                                (struct acpi_table_header **)&bgrt_tab);
+        if (ACPI_FAILURE(status))
+                return;
+
+        if (bgrt_tab->version != 1)
+                return;
+        if (bgrt_tab->image_type != 0 || !bgrt_tab->image_address)
+                return;
+
+        image = efi_lookup_mapped_addr(bgrt_tab->image_address);
+        if (!image) {
+                image = ioremap(bgrt_tab->image_address, sizeof(bmp_header));
+                ioremapped = true;
+                if (!image)
+                        return;
+        }
+
+        memcpy_fromio(&bmp_header, image, sizeof(bmp_header));
+        if (ioremapped)
+                iounmap(image);
+        bgrt_image_size = bmp_header.size;
+
+        bgrt_image = kmalloc(bgrt_image_size, GFP_KERNEL);
+        if (!bgrt_image)
+                return;
+
+        if (ioremapped) {
+                image = ioremap(bgrt_tab->image_address, bmp_header.size);
+                if (!image) {
+                        kfree(bgrt_image);
+                        bgrt_image = NULL;
+                        return;
+                }
+        }
+
+        memcpy_fromio(bgrt_image, image, bgrt_image_size);
+        if (ioremapped)
+                iounmap(image);
+}
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index f7f928c315da..aded2a91162a 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -31,6 +31,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/efi.h>
+#include <linux/efi-bgrt.h>
 #include <linux/export.h>
 #include <linux/bootmem.h>
 #include <linux/memblock.h>
@@ -745,6 +746,11 @@ void __init efi_init(void)
 #endif
 }
 
+void __init efi_late_init(void)
+{
+        efi_bgrt_init();
+}
+
 void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
 {
         u64 addr, npages;