include/asm-generic/pgtable-nop4d-hack.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _PGTABLE_NOP4D_HACK_H
   3 #define _PGTABLE_NOP4D_HACK_H
   4
   5 #ifndef __ASSEMBLY__
   6 #include <asm-generic/5level-fixup.h>
   7
   8 #define __PAGETABLE_PUD_FOLDED 1
   9
  10 /*
  11  * Having the pud type consist of a pgd gets the size right, and allows
  12  * us to conceptually access the pgd entry that this pud is folded into
  13  * without casting.
  14  */
  15 typedef struct { pgd_t pgd; } pud_t;
  16
  17 #define PUD_SHIFT       PGDIR_SHIFT
  18 #define PTRS_PER_PUD    1
  19 #define PUD_SIZE        (1UL << PUD_SHIFT)
  20 #define PUD_MASK        (~(PUD_SIZE-1))
  21
  22 /*
  23  * The "pgd_xxx()" functions here are trivial for a folded two-level
  24  * setup: the pud is never bad, and a pud always exists (as it's folded
  25  * into the pgd entry)
  26  */
  27 static inline int pgd_none(pgd_t pgd)           { return 0; }
  28 static inline int pgd_bad(pgd_t pgd)            { return 0; }
  29 static inline int pgd_present(pgd_t pgd)        { return 1; }
  30 static inline void pgd_clear(pgd_t *pgd)        { }
  31 #define pud_ERROR(pud)                          (pgd_ERROR((pud).pgd))
  32
  33 #define pgd_populate(mm, pgd, pud)              do { } while (0)
  34 /*
  35  * (puds are folded into pgds so this doesn't get actually called,
  36  * but the define is needed for a generic inline function.)
  37  */
  38 #define set_pgd(pgdptr, pgdval) set_pud((pud_t *)(pgdptr), (pud_t) { pgdval })
  39
  40 static inline pud_t *pud_offset(pgd_t *pgd, unsigned long address)
  41 {
  42         return (pud_t *)pgd;
  43 }
  44
  45 #define pud_val(x)                              (pgd_val((x).pgd))
  46 #define __pud(x)                                ((pud_t) { __pgd(x) })
  47
  48 #define pgd_page(pgd)                           (pud_page((pud_t){ pgd }))
  49 #define pgd_page_vaddr(pgd)                     (pud_page_vaddr((pud_t){ pgd }))
  50
  51 /*
  52  * allocating and freeing a pud is trivial: the 1-entry pud is
  53  * inside the pgd, so has no extra memory associated with it.
  54  */
  55 #define pud_alloc_one(mm, address)              NULL
  56 #define pud_free(mm, x)                         do { } while (0)
  57 #define __pud_free_tlb(tlb, x, a)               do { } while (0)
  58
  59 #undef  pud_addr_end
  60 #define pud_addr_end(addr, end)                 (end)
  61
  62 #endif /* __ASSEMBLY__ */
  63 #endif /* _PGTABLE_NOP4D_HACK_H */