ACPI: BGRT: use static for BGRT_SHOW kobj_attribute defines

Smatch reports this repesentative issue:

bgrt.c:26:1: warning: symbol 'bgrt_attr_version' was not declared. Should it be static?

Similar for *status,type,xoffset,yoffset

These variables are defined with the BGRT_SHOW macro.

For the definition of bgrt_attr_##_name,
the storage-class specifier should be static.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: bgrt: Use sysfs_emit

sysfs_emit is preferred to snprintf for emitting values after
commit 2efc459d06f1 ("sysfs: Add sysfs_emit and sysfs_emit_at to format
sysfs output").

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: bgrt: Fix CFI violation

clang's Control Flow Integrity requires that every indirect call has a
valid target, which is based on the type of the function pointer. The
*_show() functions in this file are written as if they will be called
from dev_attr_show(); however, they will be called from
sysfs_kf_seq_show() because the files were created by
sysfs_create_group() and the sysfs ops are based on kobj_sysfs_ops
because of kobject_add_and_create(). Because the *_show() functions do
not match the type of the show() member in struct kobj_attribute, there
is a CFI violation.

$ cat /sys/firmware/acpi/bgrt/{status,type,version,{x,y}offset}}
1
0
1
522
307

$ dmesg | grep "CFI failure"
[ 267.761825] CFI failure (target: type_show.d5e1ad21498a5fd14edbc5c320906598.cfi_jt+0x0/0x8):
[ 267.762246] CFI failure (target: xoffset_show.d5e1ad21498a5fd14edbc5c320906598.cfi_jt+0x0/0x8):
[ 267.762584] CFI failure (target: status_show.d5e1ad21498a5fd14edbc5c320906598.cfi_jt+0x0/0x8):
[ 267.762973] CFI failure (target: yoffset_show.d5e1ad21498a5fd14edbc5c320906598.cfi_jt+0x0/0x8):
[ 267.763330] CFI failure (target: version_show.d5e1ad21498a5fd14edbc5c320906598.cfi_jt+0x0/0x8):

Convert these functions to the type of the show() member in struct
kobj_attribute so that there is no more CFI violation. Because these
functions are all so similar, combine them into a macro.

Fixes: d1ff4b1cdbab ("ACPI: Add support for exposing BGRT data")
Link: https://github.com/ClangBuiltLinux/linux/issues/1406
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Use DEVICE_ATTR_<RW|RO|WO> macros

Instead of open coding DEVICE_ATTR(), use the
DEVICE_ATTR_RW(), DEVICE_ATTR_RO() and DEVICE_ATTR_WO()
macros wherever possible.

This required a few functions to be renamed but the
functionality itself is unchanged.

Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

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

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 #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ACPI: BGRT: constify attribute_group structures

attribute_groups are not supposed to change at runtime. All functions
working with attribute_groups provided by <linux/sysfs.h> work with const
attribute_group. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

efi/bgrt: Enable ACPI BGRT handling on arm64

Now that the ACPI BGRT handling code has been made generic, we can
enable it for arm64.

Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
[ Updated commit log to reflect that BGRT is only enabled for arm64, and added
missing 'return' statement to the dummy acpi_parse_bgrt() function. ]
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/20170404160245.27812-8-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

efi/x86: Move the EFI BGRT init code to early init code

Before invoking the arch specific handler, efi_mem_reserve() reserves
the given memory region through memblock.

efi_bgrt_init() will call efi_mem_reserve() after mm_init(), at which
time memblock is dead and should not be used anymore.

The EFI BGRT code depends on ACPI initialization to get the BGRT ACPI
table, so move parsing of the BGRT table to ACPI early boot code to
ensure that efi_mem_reserve() in EFI BGRT code still use memblock safely.

Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-acpi@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1485868902-20401-9-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

drivers/acpi: make bgrt driver explicitly non-modular

The Kconfig for this driver is currently:

config ACPI_BGRT
bool "Boottime Graphics Resource Table support"

...meaning that it currently is not being built as a module by anyone.
Lets remove all modular references, so that when reading the driver
there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

acpi: bgrt: fix build error due to attribute change

No need to call sysfs_bin_attr_init, as the attribute is not dynamically
created. Also, we renamed the attribute, so this one isn't even valid
anymore.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Len Brown <lenb@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ACPI: bgrt: take advantage of binary sysfs groups

Attribute groups now can handle binary sysfs attributes, so clean up the
code here by using a binary attribute array. This saves us the extra
call to create the binary attribute at saves 6 lines overall.

Cc: Len Brown <lenb@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

--
I can take this in my driver-core tree if someone from ACPI acks it,
otherwise, feel free to take it through the ACPI trees instead, just
let me know.

drivers/acpi/bgrt.c | 26 ++++++++++----------------
1 file changed, 10 insertions(+), 16 deletions(-)

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>

acpi, bgrd: Add missing <linux/io.h> to drivers/acpi/bgrt.c

The ACPI BGRT driver uses ioremap() and memcpy_fromio(), which means
it needs to #include <linux/io.h>.

[ hpa: This was hidden because <asm/acpi.h> used to include <asm/trampoline.h>,
which then included <asm/io.h> ]

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336597442-9399-1-git-send-email-hpa@linux.intel.com
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Len Brown <lenb@kernel.org>

ACPI: Add support for exposing BGRT data

ACPI 5.0 adds the BGRT, a table that contains a pointer to the firmware
boot splash and associated metadata. This simple driver exposes it via
/sys/firmware/acpi in order to allow bootsplash applications to draw their
splash around the firmware image and reduce the number of jarring graphical
transitions during boot.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>