arm64: kernel: do not mark reserved memory regions as IORESOURCE_BUSY
authorArd Biesheuvel <ard.biesheuvel@linaro.org>
Tue, 24 Jan 2017 17:11:40 +0000 (17:11 +0000)
committerWill Deacon <will.deacon@arm.com>
Thu, 26 Jan 2017 12:15:13 +0000 (12:15 +0000)
commit79ba11d24b28ead94b976c4d7c8bf8e6c349eb36
tree01339627bc16d6e4951cc5b39f2f0569569c96e3
parent1c33dc1015be482ca1a248981698d75369ce8cdc
arm64: kernel: do not mark reserved memory regions as IORESOURCE_BUSY

Memory regions marked as NOMAP should not be used for general allocation
by the kernel, and should not even be covered by the linear mapping
(hence the name). However, drivers or other subsystems (such as ACPI)
that access the firmware directly may legally access them, which means
it is also reasonable for such drivers to claim them by invoking
request_resource(). Currently, this is prevented by the fact that arm64's
request_standard_resources() marks reserved regions as IORESOURCE_BUSY.

So drop the IORESOURCE_BUSY flag from these requests.

Reported-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arch/arm64/kernel/setup.c