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authorJosh Triplett <josh@joshtriplett.org>2012-09-28 17:57:05 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2012-09-29 12:21:03 -0700
commit2223af389032425e3d1a70f9cb3a63feaa654ced (patch)
tree6874c07f26b3cdc5b10e06c34e7d0f6a9f5494aa /arch
parent7bc90e01c3f66c137e7e761f574bbf883087d590 (diff)
efi: Fix the ACPI BGRT driver for images located in EFI boot services memory
The ACPI BGRT driver accesses the BIOS logo image when it initializes. However, ACPI 5.0 (which introduces the BGRT) recommends putting the logo image in EFI boot services memory, so that the OS can reclaim that memory. Production systems follow this recommendation, breaking the ACPI BGRT driver. Move the bulk of the BGRT code to run during a new EFI late initialization phase, which occurs after switching EFI to virtual mode, and after initializing ACPI, but before freeing boot services memory. Copy the BIOS logo image to kernel memory at that point, and make it accessible to the BGRT driver. Rework the existing ACPI BGRT driver to act as a simple wrapper exposing that image (and the properties from the BGRT) via sysfs. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Link: http://lkml.kernel.org/r/93ce9f823f1c1f3bb88bdd662cce08eee7a17f5d.1348876882.git.josh@joshtriplett.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/platform/efi/Makefile1
-rw-r--r--arch/x86/platform/efi/efi-bgrt.c76
-rw-r--r--arch/x86/platform/efi/efi.c6
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;