34536d7806
Add a function to early map kernel memory using huge pages. For 512k pages, just use standard page table and map in using 512k pages. For 8M pages, create a hugepd table and populate the two PGD entries with it. This function can only be used to create page tables at startup. Once the regular SLAB allocation functions replace memblock functions, this function cannot allocate new pages anymore. However it can still update existing mappings with new protections. hugepd_none() macro is moved into asm/hugetlb.h to be usable outside of mm/hugetlbpage.c early_pte_alloc_kernel() is made visible. _PAGE_HUGE flag is now displayed by ptdump. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Change ptdump display to use "huge"] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/68325bcd3b6f93127f7810418a2352c3519066d6.1589866984.git.christophe.leroy@csgroup.eu
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 Restructured Text 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.