![Kirill A. Shutemov](/assets/img/avatar_default.png)
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>
44 lines
1.2 KiB
C
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
|