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
   9 typedef 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  */
  22 static inline int pgd_none(pgd_t pgd)           { return 0; }
  23 static inline int pgd_bad(pgd_t pgd)            { return 0; }
  24 static inline int pgd_present(pgd_t pgd)        { return 1; }
  25 static 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
  36 static 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 */