1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _PGTABLE_NOPUD_H
3 #define _PGTABLE_NOPUD_H
4 
5 #ifndef __ASSEMBLY__
6 
7 #ifdef __ARCH_USE_5LEVEL_HACK
8 #include <asm-generic/pgtable-nop4d-hack.h>
9 #else
10 #include <asm-generic/pgtable-nop4d.h>
11 
12 #define __PAGETABLE_PUD_FOLDED 1
13 
14 /*
15  * Having the pud type consist of a p4d gets the size right, and allows
16  * us to conceptually access the p4d entry that this pud is folded into
17  * without casting.
18  */
19 typedef struct { p4d_t p4d; } pud_t;
20 
21 #define PUD_SHIFT	P4D_SHIFT
22 #define PTRS_PER_PUD	1
23 #define PUD_SIZE  	(1UL << PUD_SHIFT)
24 #define PUD_MASK  	(~(PUD_SIZE-1))
25 
26 /*
27  * The "p4d_xxx()" functions here are trivial for a folded two-level
28  * setup: the pud is never bad, and a pud always exists (as it's folded
29  * into the p4d entry)
30  */
31 static inline int p4d_none(p4d_t p4d)		{ return 0; }
32 static inline int p4d_bad(p4d_t p4d)		{ return 0; }
33 static inline int p4d_present(p4d_t p4d)	{ return 1; }
34 static inline void p4d_clear(p4d_t *p4d)	{ }
35 #define pud_ERROR(pud)				(p4d_ERROR((pud).p4d))
36 
37 #define p4d_populate(mm, p4d, pud)		do { } while (0)
38 #define p4d_populate_safe(mm, p4d, pud)		do { } while (0)
39 /*
40  * (puds are folded into p4ds so this doesn't get actually called,
41  * but the define is needed for a generic inline function.)
42  */
43 #define set_p4d(p4dptr, p4dval)	set_pud((pud_t *)(p4dptr), (pud_t) { p4dval })
44 
45 static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
46 {
47 	return (pud_t *)p4d;
48 }
49 
50 #define pud_val(x)				(p4d_val((x).p4d))
51 #define __pud(x)				((pud_t) { __p4d(x) })
52 
53 #define p4d_page(p4d)				(pud_page((pud_t){ p4d }))
54 #define p4d_page_vaddr(p4d)			(pud_page_vaddr((pud_t){ p4d }))
55 
56 /*
57  * allocating and freeing a pud is trivial: the 1-entry pud is
58  * inside the p4d, so has no extra memory associated with it.
59  */
60 #define pud_alloc_one(mm, address)		NULL
61 #define pud_free(mm, x)				do { } while (0)
62 #define pud_free_tlb(tlb, x, a)		        do { } while (0)
63 
64 #undef  pud_addr_end
65 #define pud_addr_end(addr, end)			(end)
66 
67 #endif /* __ASSEMBLY__ */
68 #endif /* !__ARCH_USE_5LEVEL_HACK */
69 #endif /* _PGTABLE_NOPUD_H */
70