asm-generic: introduce __ARCH_USE_5LEVEL_HACK

#ifndef _PGTABLE_NOP4D_HACK_H

#define _PGTABLE_NOP4D_HACK_H

#ifndef __ASSEMBLY__

#include <asm-generic/5level-fixup.h>

#define __PAGETABLE_PUD_FOLDED

/*

 * Having the pud type consist of a pgd gets the size right, and allows

 * us to conceptually access the pgd entry that this pud is folded into

 * without casting.

 */

typedef struct { pgd_t pgd; } pud_t;

#define PUD_SHIFT	PGDIR_SHIFT

#define PTRS_PER_PUD	1

#define PUD_SIZE	(1UL << PUD_SHIFT)

#define PUD_MASK	(~(PUD_SIZE-1))

/*

 * The "pgd_xxx()" functions here are trivial for a folded two-level

 * setup: the pud is never bad, and a pud 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 pud_ERROR(pud)				(pgd_ERROR((pud).pgd))

#define pgd_populate(mm, pgd, pud)		do { } while (0)

/*

 * (puds 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_pud((pud_t *)(pgdptr), (pud_t) { pgdval })

static inline pud_t *pud_offset(pgd_t *pgd, unsigned long address)

{

	return (pud_t *)pgd;

}

#define pud_val(x)				(pgd_val((x).pgd))

#define __pud(x)				((pud_t) { __pgd(x) })

#define pgd_page(pgd)				(pud_page((pud_t){ pgd }))

#define pgd_page_vaddr(pgd)			(pud_page_vaddr((pud_t){ pgd }))

/*

 * allocating and freeing a pud is trivial: the 1-entry pud is

 * inside the pgd, so has no extra memory associated with it.

 */

#define pud_alloc_one(mm, address)		NULL

#define pud_free(mm, x)				do { } while (0)

#define __pud_free_tlb(tlb, x, a)		do { } while (0)

#undef  pud_addr_end

#define pud_addr_end(addr, end)			(end)

#endif /* __ASSEMBLY__ */

#endif /* _PGTABLE_NOP4D_HACK_H */

#ifndef __ASSEMBLY__

#ifdef __ARCH_USE_5LEVEL_HACK

#include <asm-generic/pgtable-nop4d-hack.h>

#else

#define __PAGETABLE_PUD_FOLDED

/*

#define pud_addr_end(addr, end)			(end)

#endif /* __ASSEMBLY__ */

#endif /* !__ARCH_USE_5LEVEL_HACK */

#endif /* _PGTABLE_NOPUD_H */