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

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _PGTABLE_NOPMD_H
   3#define _PGTABLE_NOPMD_H
   4
   5#ifndef __ASSEMBLY__
   6
   7#include <asm-generic/pgtable-nopud.h>
   8
   9struct mm_struct;
  10
  11#define __PAGETABLE_PMD_FOLDED 1
  12
  13/*
  14 * Having the pmd type consist of a pud gets the size right, and allows
  15 * us to conceptually access the pud entry that this pmd is folded into
  16 * without casting.
  17 */
  18typedef struct { pud_t pud; } pmd_t;
  19
  20#define PMD_SHIFT       PUD_SHIFT
  21#define PTRS_PER_PMD    1
  22#define PMD_SIZE        (1UL << PMD_SHIFT)
  23#define PMD_MASK        (~(PMD_SIZE-1))
  24
  25/*
  26 * The "pud_xxx()" functions here are trivial for a folded two-level
  27 * setup: the pmd is never bad, and a pmd always exists (as it's folded
  28 * into the pud entry)
  29 */
  30static inline int pud_none(pud_t pud)           { return 0; }
  31static inline int pud_bad(pud_t pud)            { return 0; }
  32static inline int pud_present(pud_t pud)        { return 1; }
  33static inline void pud_clear(pud_t *pud)        { }
  34#define pmd_ERROR(pmd)                          (pud_ERROR((pmd).pud))
  35
  36#define pud_populate(mm, pmd, pte)              do { } while (0)
  37
  38/*
  39 * (pmds are folded into puds so this doesn't get actually called,
  40 * but the define is needed for a generic inline function.)
  41 */
  42#define set_pud(pudptr, pudval)                 set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
  43
  44static inline pmd_t * pmd_offset(pud_t * pud, unsigned long address)
  45{
  46        return (pmd_t *)pud;
  47}
  48#define pmd_offset pmd_offset
  49
  50#define pmd_val(x)                              (pud_val((x).pud))
  51#define __pmd(x)                                ((pmd_t) { __pud(x) } )
  52
  53#define pud_page(pud)                           (pmd_page((pmd_t){ pud }))
  54#define pud_page_vaddr(pud)                     (pmd_page_vaddr((pmd_t){ pud }))
  55
  56/*
  57 * allocating and freeing a pmd is trivial: the 1-entry pmd is
  58 * inside the pud, so has no extra memory associated with it.
  59 */
  60#define pmd_alloc_one(mm, address)              NULL
  61static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
  62{
  63}
  64#define pmd_free_tlb(tlb, x, a)         do { } while (0)
  65
  66#undef  pmd_addr_end
  67#define pmd_addr_end(addr, end)                 (end)
  68
  69#endif /* __ASSEMBLY__ */
  70
  71#endif /* _PGTABLE_NOPMD_H */
  72