diff --git a/Documentation/arm64/memory.rst b/Documentation/arm64/memory.rst index b040909e45f8..02e02175e6f5 100644 --- a/Documentation/arm64/memory.rst +++ b/Documentation/arm64/memory.rst @@ -154,11 +154,18 @@ return virtual addresses to userspace from a 48-bit range. Software can "opt-in" to receiving VAs from a 52-bit space by specifying an mmap hint parameter that is larger than 48-bit. + For example: - maybe_high_address = mmap(~0UL, size, prot, flags,...); + +.. code-block:: c + + maybe_high_address = mmap(~0UL, size, prot, flags,...); It is also possible to build a debug kernel that returns addresses from a 52-bit space by enabling the following kernel config options: + +.. code-block:: sh + CONFIG_EXPERT=y && CONFIG_ARM64_FORCE_52BIT=y Note that this option is only intended for debugging applications