tree ea0911b0e620bf947e131424f799587041275487
parent b4e18c76999b9a4965fe48c4c7c8e7dc62a6d19f
author Alexandru Elisei <alexandru.elisei@arm.com> 1586875173 +0100
committer Will Deacon <will@kernel.org> 1586964437 +0100

Check that a PCI device's memory size is power of two

According to the PCI local bus specification [1], a device's memory size
must be a power of two. This is also implicit in the mechanism that a CPU
uses to get the memory size requirement for a PCI device.

The vesa device requests a memory size that isn't a power of two.
According to the same spec [1], a device is allowed to consume more memory
than it actually requires. As a result, the amount of memory that the vesa
device now reserves has been increased.

To prevent slip-ups in the future, a few BUILD_BUG_ON statements were added
in places where the memory size is known at compile time.

[1] PCI Local Bus Specification Revision 3.0, section 6.2.5.1

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>