linux/include/asm-generic/5level-fixup.h
Kirill A. Shutemov c65e774fb3 x86/mm: Make PGDIR_SHIFT and PTRS_PER_P4D variable
For boot-time switching between 4- and 5-level paging we need to be able
to fold p4d page table level at runtime. It requires variable
PGDIR_SHIFT and PTRS_PER_P4D.

The change doesn't affect the kernel image size much:

   text	   data	    bss	    dec	    hex	filename
8628091	4734304	1368064	14730459	 e0c4db	vmlinux.before
8628393	4734340	1368064	14730797	 e0c62d	vmlinux.after

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180214111656.88514-7-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-14 13:11:14 +01:00

44 lines
1.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _5LEVEL_FIXUP_H
#define _5LEVEL_FIXUP_H
#define __ARCH_HAS_5LEVEL_HACK
#define __PAGETABLE_P4D_FOLDED
#define P4D_SHIFT PGDIR_SHIFT
#define P4D_SIZE PGDIR_SIZE
#define P4D_MASK PGDIR_MASK
#define MAX_PTRS_PER_P4D 1
#define PTRS_PER_P4D 1
#define p4d_t pgd_t
#define pud_alloc(mm, p4d, address) \
((unlikely(pgd_none(*(p4d))) && __pud_alloc(mm, p4d, address)) ? \
NULL : pud_offset(p4d, address))
#define p4d_alloc(mm, pgd, address) (pgd)
#define p4d_offset(pgd, start) (pgd)
#define p4d_none(p4d) 0
#define p4d_bad(p4d) 0
#define p4d_present(p4d) 1
#define p4d_ERROR(p4d) do { } while (0)
#define p4d_clear(p4d) pgd_clear(p4d)
#define p4d_val(p4d) pgd_val(p4d)
#define p4d_populate(mm, p4d, pud) pgd_populate(mm, p4d, pud)
#define p4d_page(p4d) pgd_page(p4d)
#define p4d_page_vaddr(p4d) pgd_page_vaddr(p4d)
#define __p4d(x) __pgd(x)
#define set_p4d(p4dp, p4d) set_pgd(p4dp, p4d)
#undef p4d_free_tlb
#define p4d_free_tlb(tlb, x, addr) do { } while (0)
#define p4d_free(mm, x) do { } while (0)
#define __p4d_free_tlb(tlb, x, addr) do { } while (0)
#undef p4d_addr_end
#define p4d_addr_end(addr, end) (end)
#endif