Linux Kernel  3.7.1
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pgtable-nopud.h
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1 #ifndef _PGTABLE_NOPUD_H
2 #define _PGTABLE_NOPUD_H
3 
4 #ifndef __ASSEMBLY__
5 
6 #define __PAGETABLE_PUD_FOLDED
7 
8 /*
9  * Having the pud type consist of a pgd gets the size right, and allows
10  * us to conceptually access the pgd entry that this pud is folded into
11  * without casting.
12  */
13 typedef struct { pgd_t pgd; } pud_t;
14 
15 #define PUD_SHIFT PGDIR_SHIFT
16 #define PTRS_PER_PUD 1
17 #define PUD_SIZE (1UL << PUD_SHIFT)
18 #define PUD_MASK (~(PUD_SIZE-1))
19 
20 /*
21  * The "pgd_xxx()" functions here are trivial for a folded two-level
22  * setup: the pud is never bad, and a pud always exists (as it's folded
23  * into the pgd entry)
24  */
25 static inline int pgd_none(pgd_t pgd) { return 0; }
26 static inline int pgd_bad(pgd_t pgd) { return 0; }
27 static inline int pgd_present(pgd_t pgd) { return 1; }
28 static inline void pgd_clear(pgd_t *pgd) { }
29 #define pud_ERROR(pud) (pgd_ERROR((pud).pgd))
30 
31 #define pgd_populate(mm, pgd, pud) do { } while (0)
32 /*
33  * (puds are folded into pgds so this doesn't get actually called,
34  * but the define is needed for a generic inline function.)
35  */
36 #define set_pgd(pgdptr, pgdval) set_pud((pud_t *)(pgdptr), (pud_t) { pgdval })
37 
38 static inline pud_t * pud_offset(pgd_t * pgd, unsigned long address)
39 {
40  return (pud_t *)pgd;
41 }
42 
43 #define pud_val(x) (pgd_val((x).pgd))
44 #define __pud(x) ((pud_t) { __pgd(x) } )
45 
46 #define pgd_page(pgd) (pud_page((pud_t){ pgd }))
47 #define pgd_page_vaddr(pgd) (pud_page_vaddr((pud_t){ pgd }))
48 
49 /*
50  * allocating and freeing a pud is trivial: the 1-entry pud is
51  * inside the pgd, so has no extra memory associated with it.
52  */
53 #define pud_alloc_one(mm, address) NULL
54 #define pud_free(mm, x) do { } while (0)
55 #define __pud_free_tlb(tlb, x, a) do { } while (0)
56 
57 #undef pud_addr_end
58 #define pud_addr_end(addr, end) (end)
59 
60 #endif /* __ASSEMBLY__ */
61 #endif /* _PGTABLE_NOPUD_H */