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 int pud_user(pud_t pud)		{ return 0; }
34 static inline int pud_leaf(pud_t pud)		{ return 0; }
35 static inline void pud_clear(pud_t *pud)	{ }
36 #define pmd_ERROR(pmd)				(pud_ERROR((pmd).pud))
37 
38 #define pud_populate(mm, pmd, pte)		do { } while (0)
39 
40 /*
41  * (pmds are folded into puds so this doesn't get actually called,
42  * but the define is needed for a generic inline function.)
43  */
44 #define set_pud(pudptr, pudval)			set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
45 
46 static inline pmd_t * pmd_offset(pud_t * pud, unsigned long address)
47 {
48 	return (pmd_t *)pud;
49 }
50 #define pmd_offset pmd_offset
51 
52 #define pmd_val(x)				(pud_val((x).pud))
53 #define __pmd(x)				((pmd_t) { __pud(x) } )
54 
55 #define pud_page(pud)				(pmd_page((pmd_t){ pud }))
56 #define pud_pgtable(pud)			((pmd_t *)(pmd_page_vaddr((pmd_t){ pud })))
57 
58 /*
59  * allocating and freeing a pmd is trivial: the 1-entry pmd is
60  * inside the pud, so has no extra memory associated with it.
61  */
62 #define pmd_alloc_one(mm, address)		NULL
63 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
64 {
65 }
66 #define pmd_free_tlb(tlb, x, a)		do { } while (0)
67 
68 #undef  pmd_addr_end
69 #define pmd_addr_end(addr, end)			(end)
70 
71 #endif /* __ASSEMBLY__ */
72 
73 #endif /* _PGTABLE_NOPMD_H */
74