1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _PGTABLE_NOPUD_H
3 #define _PGTABLE_NOPUD_H
4 
5 #ifndef __ASSEMBLY__
6 
7 #include <asm-generic/pgtable-nop4d.h>
8 
9 #define __PAGETABLE_PUD_FOLDED 1
10 
11 /*
12  * Having the pud type consist of a p4d gets the size right, and allows
13  * us to conceptually access the p4d entry that this pud is folded into
14  * without casting.
15  */
16 typedef struct { p4d_t p4d; } pud_t;
17 
18 #define PUD_SHIFT	P4D_SHIFT
19 #define PTRS_PER_PUD	1
20 #define PUD_SIZE  	(1UL << PUD_SHIFT)
21 #define PUD_MASK  	(~(PUD_SIZE-1))
22 
23 /*
24  * The "p4d_xxx()" functions here are trivial for a folded two-level
25  * setup: the pud is never bad, and a pud always exists (as it's folded
26  * into the p4d entry)
27  */
28 static inline int p4d_none(p4d_t p4d)		{ return 0; }
29 static inline int p4d_bad(p4d_t p4d)		{ return 0; }
30 static inline int p4d_present(p4d_t p4d)	{ return 1; }
31 static inline void p4d_clear(p4d_t *p4d)	{ }
32 #define pud_ERROR(pud)				(p4d_ERROR((pud).p4d))
33 
34 #define p4d_populate(mm, p4d, pud)		do { } while (0)
35 #define p4d_populate_safe(mm, p4d, pud)		do { } while (0)
36 /*
37  * (puds are folded into p4ds so this doesn't get actually called,
38  * but the define is needed for a generic inline function.)
39  */
40 #define set_p4d(p4dptr, p4dval)	set_pud((pud_t *)(p4dptr), (pud_t) { p4dval })
41 
42 static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
43 {
44 	return (pud_t *)p4d;
45 }
46 #define pud_offset pud_offset
47 
48 #define pud_val(x)				(p4d_val((x).p4d))
49 #define __pud(x)				((pud_t) { __p4d(x) })
50 
51 #define p4d_page(p4d)				(pud_page((pud_t){ p4d }))
52 #define p4d_page_vaddr(p4d)			(pud_page_vaddr((pud_t){ p4d }))
53 
54 /*
55  * allocating and freeing a pud is trivial: the 1-entry pud is
56  * inside the p4d, so has no extra memory associated with it.
57  */
58 #define pud_alloc_one(mm, address)		NULL
59 #define pud_free(mm, x)				do { } while (0)
60 #define pud_free_tlb(tlb, x, a)		        do { } while (0)
61 
62 #undef  pud_addr_end
63 #define pud_addr_end(addr, end)			(end)
64 
65 #endif /* __ASSEMBLY__ */
66 #endif /* _PGTABLE_NOPUD_H */
67