/* SPDX-License-Identifier: GPL-2.0 */
  #ifndef _PGTABLE_NOP4D_H
  #define _PGTABLE_NOP4D_H
  
  #ifndef __ASSEMBLY__
  
  #define __PAGETABLE_P4D_FOLDED
  
  typedef struct { pgd_t pgd; } p4d_t;
  
  #define P4D_SHIFT	PGDIR_SHIFT
  #define PTRS_PER_P4D	1
  #define P4D_SIZE	(1UL << P4D_SHIFT)
  #define P4D_MASK	(~(P4D_SIZE-1))
  
  /*
   * The "pgd_xxx()" functions here are trivial for a folded two-level
   * setup: the p4d is never bad, and a p4d always exists (as it's folded
   * into the pgd entry)
   */
  static inline int pgd_none(pgd_t pgd)		{ return 0; }
  static inline int pgd_bad(pgd_t pgd)		{ return 0; }
  static inline int pgd_present(pgd_t pgd)	{ return 1; }
  static inline void pgd_clear(pgd_t *pgd)	{ }
  #define p4d_ERROR(p4d)				(pgd_ERROR((p4d).pgd))
  
  #define pgd_populate(mm, pgd, p4d)		do { } while (0)
  /*
   * (p4ds are folded into pgds so this doesn't get actually called,
   * but the define is needed for a generic inline function.)
   */
  #define set_pgd(pgdptr, pgdval)	set_p4d((p4d_t *)(pgdptr), (p4d_t) { pgdval })
  
  static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
  {
  	return (p4d_t *)pgd;
  }
  
  #define p4d_val(x)				(pgd_val((x).pgd))
  #define __p4d(x)				((p4d_t) { __pgd(x) })
  
  #define pgd_page(pgd)				(p4d_page((p4d_t){ pgd }))
  #define pgd_page_vaddr(pgd)			(p4d_page_vaddr((p4d_t){ pgd }))
  
  /*
   * allocating and freeing a p4d is trivial: the 1-entry p4d is
   * inside the pgd, so has no extra memory associated with it.
   */
  #define p4d_alloc_one(mm, address)		NULL
  #define p4d_free(mm, x)				do { } while (0)
  #define __p4d_free_tlb(tlb, x, a)		do { } while (0)
  
  #undef  p4d_addr_end
  #define p4d_addr_end(addr, end)			(end)
  
  #endif /* __ASSEMBLY__ */
  #endif /* _PGTABLE_NOP4D_H */