For legibility, use the existing BIT_ULL() to generate the u64 type EFI
memory attribute macros.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

UEFI 2.11 introduced EFI_MEMORY_HOT_PLUGGABLE to annotate system memory
regions that are 'cold plugged' at boot, i.e., hot pluggable memory that
is available from early boot, and described as system RAM by the
firmware.

Existing loaders and EFI applications running in the boot context will
happily use this memory for allocating data structures that cannot be
freed or moved at runtime, and this prevents the memory from being
unplugged. Going forward, the new EFI_MEMORY_HOT_PLUGGABLE attribute
should be tested, and memory annotated as such should be avoided for
such allocations.

In the EFI stub, there are a couple of occurrences where, instead of the
high-level AllocatePages() UEFI boot service, a low-level code sequence
is used that traverses the EFI memory map and carves out the requested
number of pages from a free region. This is needed, e.g., for allocating
as low as possible, or for allocating pages at random.

While AllocatePages() should presumably avoid special purpose memory and
cold plugged regions, this manual approach needs to incorporate this
logic itself, in order to prevent the kernel itself from ending up in a
hot unpluggable region, preventing it from being unplugged.

So add the EFI_MEMORY_HOTPLUGGABLE macro definition, and check for it
where appropriate.

Cc: stable@vger.kernel.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

UGA is the EFI graphical output protocol that preceded GOP, and has been
long obsolete. Drop support for it from the x86 implementation of the
EFI stub - other architectures never bothered to implement it (save for
ia64)

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Drop support for the EFI_PROPERTIES_TABLE. It was a failed, short-lived
experiment that broke the boot both on Linux and Windows, and was
replaced by the EFI_MEMORY_ATTRIBUTES_TABLE shortly after.

Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Nicolas Saenz Julienne <nsaenz@amazon.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Since commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture"),
this is not used anymore.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

While efi_memory_attributes_table_t::entry isn't used directly as an
array, it is used as a base for pointer arithmetic. The type is wrong
as it's not technically an array of efi_memory_desc_t's; they could be
larger. Regardless, leave the type unchanged and remove the old style
"0" array size. Additionally replace the open-coded entry offset code
with the existing efi_memdesc_ptr() helper.

Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

The "early" part of the helper's name isn't accurate[1]. Drop it in
preparation for adding a new (not early) usage.

Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/lkml/CAMj1kXEyDjH0uu3Z4eBesV3PEnKGi5ArXXMp7R-hn8HdRytiPg@mail.gmail.com [1]
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

0c18184de990 ("platform/x86: apple-gmux: support MMIO gmux on T2 Macs")
brought support for T2 Macs in apple-gmux. But in order to use dual GPU,
the integrated GPU has to be enabled. On such dual GPU EFI Macs, the EFI
stub needs to report that it is booting macOS in order to prevent the
firmware from disabling the iGPU.

This patch is also applicable for some non T2 Intel Macs.

Based on this patch for GRUB by Andreas Heider <andreas@heider.io>:
https://lists.gnu.org/archive/html/grub-devel/2013-12/msg00442.html

Credits also goto Kerem Karabay <kekrby@gmail.com> for helping porting
the patch to the Linux kernel.

Cc: Orlando Chamberlain <orlandoch.dev@gmail.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
[ardb: limit scope using list of DMI matches provided by Lukas and Orlando]
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Tested-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

The smbios.c source file is not currently included in the x86 build, and
before we can do so, it needs some tweaks to build correctly in
combination with the EFI mixed mode support.

Reviewed-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

The UEFI specification does not make any mention of a maximum variable
name size, so the headers and implementation shouldn't claim that one
exists either.

Comments referring to this limit have been removed or rewritten, as this
is an implementation detail local to the Linux kernel.

Where appropriate, the magic value of 1024 has been replaced with
EFI_VAR_NAME_LEN, as this is used for the efi_variable struct
definition. This in itself does not change any behavior, but should
serve as points of interest when making future changes in the same area.

A related build-time check has been added to ensure that the special
512 byte sized buffer will not overflow with a potentially decreased
EFI_VAR_NAME_LEN.

Signed-off-by: Tim Schumacher <timschumi@gmx.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>