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1da177e4 LT |
1 | #ifndef _ASM_PGALLOC_H |
2 | #define _ASM_PGALLOC_H | |
3 | ||
4 | #include <linux/gfp.h> | |
5 | #include <linux/mm.h> | |
6 | #include <linux/threads.h> | |
7 | #include <asm/processor.h> | |
8 | #include <asm/fixmap.h> | |
9 | ||
10 | #include <asm/cache.h> | |
11 | ||
12 | /* Allocate the top level pgd (page directory) | |
13 | * | |
14 | * Here (for 64 bit kernels) we implement a Hybrid L2/L3 scheme: we | |
15 | * allocate the first pmd adjacent to the pgd. This means that we can | |
16 | * subtract a constant offset to get to it. The pmd and pgd sizes are | |
17 | * arranged so that a single pmd covers 4GB (giving a full LP64 | |
18 | * process access to 8TB) so our lookups are effectively L2 for the | |
19 | * first 4GB of the kernel (i.e. for all ILP32 processes and all the | |
20 | * kernel for machines with under 4GB of memory) */ | |
21 | static inline pgd_t *pgd_alloc(struct mm_struct *mm) | |
22 | { | |
23 | pgd_t *pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, | |
24 | PGD_ALLOC_ORDER); | |
25 | pgd_t *actual_pgd = pgd; | |
26 | ||
27 | if (likely(pgd != NULL)) { | |
28 | memset(pgd, 0, PAGE_SIZE<<PGD_ALLOC_ORDER); | |
29 | #ifdef __LP64__ | |
30 | actual_pgd += PTRS_PER_PGD; | |
31 | /* Populate first pmd with allocated memory. We mark it | |
32 | * with PxD_FLAG_ATTACHED as a signal to the system that this | |
33 | * pmd entry may not be cleared. */ | |
34 | __pgd_val_set(*actual_pgd, (PxD_FLAG_PRESENT | | |
35 | PxD_FLAG_VALID | | |
36 | PxD_FLAG_ATTACHED) | |
37 | + (__u32)(__pa((unsigned long)pgd) >> PxD_VALUE_SHIFT)); | |
38 | /* The first pmd entry also is marked with _PAGE_GATEWAY as | |
39 | * a signal that this pmd may not be freed */ | |
40 | __pgd_val_set(*pgd, PxD_FLAG_ATTACHED); | |
41 | #endif | |
42 | } | |
43 | return actual_pgd; | |
44 | } | |
45 | ||
46 | static inline void pgd_free(pgd_t *pgd) | |
47 | { | |
48 | #ifdef __LP64__ | |
49 | pgd -= PTRS_PER_PGD; | |
50 | #endif | |
51 | free_pages((unsigned long)pgd, PGD_ALLOC_ORDER); | |
52 | } | |
53 | ||
54 | #if PT_NLEVELS == 3 | |
55 | ||
56 | /* Three Level Page Table Support for pmd's */ | |
57 | ||
58 | static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmd) | |
59 | { | |
60 | __pgd_val_set(*pgd, (PxD_FLAG_PRESENT | PxD_FLAG_VALID) + | |
61 | (__u32)(__pa((unsigned long)pmd) >> PxD_VALUE_SHIFT)); | |
62 | } | |
63 | ||
64 | static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address) | |
65 | { | |
66 | pmd_t *pmd = (pmd_t *)__get_free_pages(GFP_KERNEL|__GFP_REPEAT, | |
67 | PMD_ORDER); | |
68 | if (pmd) | |
69 | memset(pmd, 0, PAGE_SIZE<<PMD_ORDER); | |
70 | return pmd; | |
71 | } | |
72 | ||
73 | static inline void pmd_free(pmd_t *pmd) | |
74 | { | |
75 | #ifdef __LP64__ | |
76 | if(pmd_flag(*pmd) & PxD_FLAG_ATTACHED) | |
77 | /* This is the permanent pmd attached to the pgd; | |
78 | * cannot free it */ | |
79 | return; | |
80 | #endif | |
81 | free_pages((unsigned long)pmd, PMD_ORDER); | |
82 | } | |
83 | ||
84 | #else | |
85 | ||
86 | /* Two Level Page Table Support for pmd's */ | |
87 | ||
88 | /* | |
89 | * allocating and freeing a pmd is trivial: the 1-entry pmd is | |
90 | * inside the pgd, so has no extra memory associated with it. | |
91 | */ | |
92 | ||
93 | #define pmd_alloc_one(mm, addr) ({ BUG(); ((pmd_t *)2); }) | |
94 | #define pmd_free(x) do { } while (0) | |
95 | #define pgd_populate(mm, pmd, pte) BUG() | |
96 | ||
97 | #endif | |
98 | ||
99 | static inline void | |
100 | pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte) | |
101 | { | |
102 | #ifdef __LP64__ | |
103 | /* preserve the gateway marker if this is the beginning of | |
104 | * the permanent pmd */ | |
105 | if(pmd_flag(*pmd) & PxD_FLAG_ATTACHED) | |
106 | __pmd_val_set(*pmd, (PxD_FLAG_PRESENT | | |
107 | PxD_FLAG_VALID | | |
108 | PxD_FLAG_ATTACHED) | |
109 | + (__u32)(__pa((unsigned long)pte) >> PxD_VALUE_SHIFT)); | |
110 | else | |
111 | #endif | |
112 | __pmd_val_set(*pmd, (PxD_FLAG_PRESENT | PxD_FLAG_VALID) | |
113 | + (__u32)(__pa((unsigned long)pte) >> PxD_VALUE_SHIFT)); | |
114 | } | |
115 | ||
116 | #define pmd_populate(mm, pmd, pte_page) \ | |
117 | pmd_populate_kernel(mm, pmd, page_address(pte_page)) | |
118 | ||
119 | static inline struct page * | |
120 | pte_alloc_one(struct mm_struct *mm, unsigned long address) | |
121 | { | |
122 | struct page *page = alloc_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); | |
123 | return page; | |
124 | } | |
125 | ||
126 | static inline pte_t * | |
127 | pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr) | |
128 | { | |
129 | pte_t *pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); | |
130 | return pte; | |
131 | } | |
132 | ||
133 | static inline void pte_free_kernel(pte_t *pte) | |
134 | { | |
135 | free_page((unsigned long)pte); | |
136 | } | |
137 | ||
138 | #define pte_free(page) pte_free_kernel(page_address(page)) | |
139 | ||
1da177e4 LT |
140 | #define check_pgt_cache() do { } while (0) |
141 | ||
142 | #endif |