1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _PGTABLE_NOP4D_H
3 #define _PGTABLE_NOP4D_H
4
5 #ifndef __ASSEMBLY__
6
7 #define __PAGETABLE_P4D_FOLDED 1
8
9 typedef struct { pgd_t pgd; } p4d_t;
10
11 #define P4D_SHIFT PGDIR_SHIFT
12 #define PTRS_PER_P4D 1
13 #define P4D_SIZE (1UL << P4D_SHIFT)
14 #define P4D_MASK (~(P4D_SIZE-1))
15
16 /*
17 * The "pgd_xxx()" functions here are trivial for a folded two-level
18 * setup: the p4d is never bad, and a p4d always exists (as it's folded
19 * into the pgd entry)
20 */
21 static inline int pgd_none(pgd_t pgd) { return 0; }
22 static inline int pgd_bad(pgd_t pgd) { return 0; }
23 static inline int pgd_present(pgd_t pgd) { return 1; }
24 static inline void pgd_clear(pgd_t *pgd) { }
25 #define p4d_ERROR(p4d) (pgd_ERROR((p4d).pgd))
26
27 #define pgd_populate(mm, pgd, p4d) do { } while (0)
28 #define pgd_populate_safe(mm, pgd, p4d) do { } while (0)
29 /*
30 * (p4ds are folded into pgds so this doesn't get actually called,
31 * but the define is needed for a generic inline function.)
32 */
33 #define set_pgd(pgdptr, pgdval) set_p4d((p4d_t *)(pgdptr), (p4d_t) { pgdval })
34
35 static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
36 {
37 return (p4d_t *)pgd;
38 }
39
40 #define p4d_val(x) (pgd_val((x).pgd))
41 #define __p4d(x) ((p4d_t) { __pgd(x) })
42
43 #define pgd_page(pgd) (p4d_page((p4d_t){ pgd }))
44 #define pgd_page_vaddr(pgd) ((unsigned long)(p4d_pgtable((p4d_t){ pgd })))
45
46 /*
47 * allocating and freeing a p4d is trivial: the 1-entry p4d is
48 * inside the pgd, so has no extra memory associated with it.
49 */
50 #define p4d_alloc_one(mm, address) NULL
51 #define p4d_free(mm, x) do { } while (0)
52 #define p4d_free_tlb(tlb, x, a) do { } while (0)
53
54 #undef p4d_addr_end
55 #define p4d_addr_end(addr, end) (end)
56
57 #endif /* __ASSEMBLY__ */
58 #endif /* _PGTABLE_NOP4D_H */
59
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