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>

diff --git a/arch/x86/platform/efi/Makefile b/arch/x86/platform/efi/Makefile
index 73b8be0f3675edd32081adf1a255a51647e525c9..6db1cc4c75342ca3aa565fe6319e771900755ae0 100644 (file)
--- 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 (file)
index 0000000..f6a0c1b
--- /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 f7f928c315da1659b755f23fe63b3c49b2b5e525..aded2a91162a8af12ad104d047544afce91ff4c4 100644 (file)
--- 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;

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 80998958cf45381f4e1ef6f585b9467b31d1e4b3..119d58db834298ff950251bf07ae0fc5436ab1ca 100644 (file)
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -385,8 +385,8 @@ config ACPI_CUSTOM_METHOD
          to override that restriction).
 
 config ACPI_BGRT
-        tristate "Boottime Graphics Resource Table support"
-        default n
+       bool "Boottime Graphics Resource Table support"
+       depends on EFI
         help
          This driver adds support for exposing the ACPI Boottime Graphics
          Resource Table, which allows the operating system to obtain

diff --git a/drivers/acpi/bgrt.c b/drivers/acpi/bgrt.c
index 6680df36b9634f414cc7438ca57590bef0c8cc71..be60399585456a76b973208c8674833c766fa824 100644 (file)
--- a/drivers/acpi/bgrt.c
+++ b/drivers/acpi/bgrt.c
@@ -1,5 +1,6 @@
 /*
  * Copyright 2012 Red Hat, Inc <mjg@redhat.com>
+ * Copyright 2012 Intel Corporation
  *
  * 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
@@ -11,20 +12,10 @@
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/sysfs.h>
-#include <linux/io.h>
-#include <acpi/acpi.h>
-#include <acpi/acpi_bus.h>
+#include <linux/efi-bgrt.h>
 
-static struct acpi_table_bgrt *bgrt_tab;
 static struct kobject *bgrt_kobj;
 
-struct bmp_header {
-       u16 id;
-       u32 size;
-} __attribute ((packed));
-
-static struct bmp_header bmp_header;
-
 static ssize_t show_version(struct device *dev,
                            struct device_attribute *attr, char *buf)
 {
@@ -63,18 +54,7 @@ static DEVICE_ATTR(yoffset, S_IRUGO, show_yoffset, NULL);
 static ssize_t show_image(struct file *file, struct kobject *kobj,
               struct bin_attribute *attr, char *buf, loff_t off, size_t count)
 {
-       int size = attr->size;
-       void __iomem *image = attr->private;
-
-       if (off >= size) {
-               count = 0;
-       } else {
-               if (off + count > size)
-                       count = size - off;
-
-               memcpy_fromio(buf, image+off, count);
-       }
-
+       memcpy(buf, attr->private + off, count);
        return count;
 }
 
@@ -101,45 +81,18 @@ static struct attribute_group bgrt_attribute_group = {
 
 static int __init bgrt_init(void)
 {
-       acpi_status status;
        int ret;
-       void __iomem *bgrt;
 
-       if (acpi_disabled)
-               return -ENODEV;
-
-       status = acpi_get_table("BGRT", 0,
-                               (struct acpi_table_header **)&bgrt_tab);
-
-       if (ACPI_FAILURE(status))
+       if (!bgrt_image)
                return -ENODEV;
 
        sysfs_bin_attr_init(&image_attr);
-
-       bgrt = ioremap(bgrt_tab->image_address, sizeof(struct bmp_header));
-
-       if (!bgrt) {
-               ret = -EINVAL;
-               goto out_err;
-       }
-
-       memcpy_fromio(&bmp_header, bgrt, sizeof(bmp_header));
-       image_attr.size = bmp_header.size;
-       iounmap(bgrt);
-
-       image_attr.private = ioremap(bgrt_tab->image_address, image_attr.size);
-
-       if (!image_attr.private) {
-               ret = -EINVAL;
-               goto out_err;
-       }
-
+       image_attr.private = bgrt_image;
+       image_attr.size = bgrt_image_size;
 
        bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
-       if (!bgrt_kobj) {
-               ret = -EINVAL;
-               goto out_iounmap;
-       }
+       if (!bgrt_kobj)
+               return -EINVAL;
 
        ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
        if (ret)
@@ -155,22 +108,11 @@ out_group:
        sysfs_remove_group(bgrt_kobj, &bgrt_attribute_group);
 out_kobject:
        kobject_put(bgrt_kobj);
-out_iounmap:
-       iounmap(image_attr.private);
-out_err:
        return ret;
 }
 
-static void __exit bgrt_exit(void)
-{
-       iounmap(image_attr.private);
-       sysfs_remove_group(bgrt_kobj, &bgrt_attribute_group);
-       sysfs_remove_bin_file(bgrt_kobj, &image_attr);
-}
-
 module_init(bgrt_init);
-module_exit(bgrt_exit);
 
-MODULE_AUTHOR("Matthew Garrett");
+MODULE_AUTHOR("Matthew Garrett, Josh Triplett <josh@joshtriplett.org>");
 MODULE_DESCRIPTION("BGRT boot graphic support");
 MODULE_LICENSE("GPL");

diff --git a/include/linux/efi-bgrt.h b/include/linux/efi-bgrt.h
new file mode 100644 (file)
index 0000000..051b21f
--- /dev/null
+++ b/include/linux/efi-bgrt.h
@@ -0,0 +1,21 @@
+#ifndef _LINUX_EFI_BGRT_H
+#define _LINUX_EFI_BGRT_H
+
+#ifdef CONFIG_ACPI_BGRT
+
+#include <linux/acpi.h>
+
+void efi_bgrt_init(void);
+
+/* The BGRT data itself; only valid if bgrt_image != NULL. */
+extern void *bgrt_image;
+extern size_t bgrt_image_size;
+extern struct acpi_table_bgrt *bgrt_tab;
+
+#else /* !CONFIG_ACPI_BGRT */
+
+static inline void efi_bgrt_init(void) {}
+
+#endif /* !CONFIG_ACPI_BGRT */
+
+#endif /* _LINUX_EFI_BGRT_H */

diff --git a/include/linux/efi.h b/include/linux/efi.h
index fff135d9375e05274afbc046bf4d04339d7c845f..8670eb1eb8cd27aea69ad00c6b08328e65b7ed79 100644 (file)
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -497,8 +497,10 @@ extern void efi_memmap_walk (efi_freemem_callback_t callback, void *arg);
 extern void efi_gettimeofday (struct timespec *ts);
 extern void efi_enter_virtual_mode (void);     /* switch EFI to virtual mode, if possible */
 #ifdef CONFIG_X86
+extern void efi_late_init(void);
 extern void efi_free_boot_services(void);
 #else
+static inline void efi_late_init(void) {}
 static inline void efi_free_boot_services(void) {}
 #endif
 extern void __iomem *efi_lookup_mapped_addr(u64 phys_addr);

diff --git a/init/main.c b/init/main.c
index d61ec542205c1f69cc5c1a9438f19c32f3dfcd8d..db34c0ec47113a832695a3087ddd3129fdd2c976 100644 (file)
--- a/init/main.c
+++ b/init/main.c
@@ -631,8 +631,10 @@ asmlinkage void __init start_kernel(void)
        acpi_early_init(); /* before LAPIC and SMP init */
        sfi_init_late();
 
-       if (efi_enabled)
+       if (efi_enabled) {
+               efi_late_init();
                efi_free_boot_services();
+       }
 
        ftrace_init();