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 
9 struct 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  */
18 typedef 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  */
30 static inline int pud_none(pud_t pud)		{ return 0; }
31 static inline int pud_bad(pud_t pud)		{ return 0; }
32 static inline int pud_present(pud_t pud)	{ return 1; }
33 static 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 
44 static inline pmd_t * pmd_offset(pud_t * pud, unsigned long address)
45 {
46 	return (pmd_t *)pud;
47 }
48 
49 #define pmd_val(x)				(pud_val((x).pud))
50 #define __pmd(x)				((pmd_t) { __pud(x) } )
51 
52 #define pud_page(pud)				(pmd_page((pmd_t){ pud }))
53 #define pud_page_vaddr(pud)			(pmd_page_vaddr((pmd_t){ pud }))
54 
55 /*
56  * allocating and freeing a pmd is trivial: the 1-entry pmd is
57  * inside the pud, so has no extra memory associated with it.
58  */
59 #define pmd_alloc_one(mm, address)		NULL
60 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
61 {
62 }
63 #define pmd_free_tlb(tlb, x, a)		do { } while (0)
64 
65 #undef  pmd_addr_end
66 #define pmd_addr_end(addr, end)			(end)
67 
68 #endif /* __ASSEMBLY__ */
69 
70 #endif /* _PGTABLE_NOPMD_H */
71