LXR linux/include/asm-generic/pgtable-nop4d.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _PGTABLE_NOP4D_H
   3#define _PGTABLE_NOP4D_H
   4
   5#ifndef __ASSEMBLY__
   6
   7#define __PAGETABLE_P4D_FOLDED 1
   8
   9typedef struct { pgd_t pgd; } p4d_t;
  10
  11#define P4D_SHIFT               PGDIR_SHIFT
  12#define MAX_PTRS_PER_P4D        1
  13#define PTRS_PER_P4D            1
  14#define P4D_SIZE                (1UL << P4D_SHIFT)
  15#define P4D_MASK                (~(P4D_SIZE-1))
  16
  17/*
  18 * The "pgd_xxx()" functions here are trivial for a folded two-level
  19 * setup: the p4d is never bad, and a p4d always exists (as it's folded
  20 * into the pgd entry)
  21 */
  22static inline int pgd_none(pgd_t pgd)           { return 0; }
  23static inline int pgd_bad(pgd_t pgd)            { return 0; }
  24static inline int pgd_present(pgd_t pgd)        { return 1; }
  25static inline void pgd_clear(pgd_t *pgd)        { }
  26#define p4d_ERROR(p4d)                          (pgd_ERROR((p4d).pgd))
  27
  28#define pgd_populate(mm, pgd, p4d)              do { } while (0)
  29#define pgd_populate_safe(mm, pgd, p4d)         do { } while (0)
  30/*
  31 * (p4ds are folded into pgds so this doesn't get actually called,
  32 * but the define is needed for a generic inline function.)
  33 */
  34#define set_pgd(pgdptr, pgdval) set_p4d((p4d_t *)(pgdptr), (p4d_t) { pgdval })
  35
  36static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
  37{
  38        return (p4d_t *)pgd;
  39}
  40
  41#define p4d_val(x)                              (pgd_val((x).pgd))
  42#define __p4d(x)                                ((p4d_t) { __pgd(x) })
  43
  44#define pgd_page(pgd)                           (p4d_page((p4d_t){ pgd }))
  45#define pgd_page_vaddr(pgd)                     (p4d_page_vaddr((p4d_t){ pgd }))
  46
  47/*
  48 * allocating and freeing a p4d is trivial: the 1-entry p4d is
  49 * inside the pgd, so has no extra memory associated with it.
  50 */
  51#define p4d_alloc_one(mm, address)              NULL
  52#define p4d_free(mm, x)                         do { } while (0)
  53#define __p4d_free_tlb(tlb, x, a)               do { } while (0)
  54
  55#undef  p4d_addr_end
  56#define p4d_addr_end(addr, end)                 (end)
  57
  58#endif /* __ASSEMBLY__ */
  59#endif /* _PGTABLE_NOP4D_H */
  60