a1439d8948
EFI runtime services are remapped into the lower 1 GiB of virtual address space at boot, so they are guaranteed to be able to co-exist with the kernel virtual mappings without the need to allocate space for them in the kernel's vmalloc region, which is rather small. This means those mappings are covered by TTBR0 when LPAE PAN is enabled, and so 'user' access must be enabled while such calls are in progress. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.