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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 1 | #ifndef _GENERIC_RMAP_H |
| 2 | #define _GENERIC_RMAP_H |
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| 3 | /* |
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| 4 | * linux/include/asm-generic/rmap.h |
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| 5 | * |
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| 6 | * Architecture dependent parts of the reverse mapping code, |
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| 7 | * this version should work for most architectures with a |
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| 8 | * 'normal' page table layout. |
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| 9 | * |
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| 10 | * We use the struct page of the page table page to find out |
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| 11 | * the process and full address of a page table entry: |
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| 12 | * - page->mapping points to the process' mm_struct |
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| 13 | * - page->index has the high bits of the address |
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| 14 | * - the lower bits of the address are calculated from the |
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| 15 | * offset of the page table entry within the page table page |
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| 16 | * |
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| 17 | * For CONFIG_HIGHPTE, we need to represent the address of a pte in a |
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| 18 | * scalar pte_addr_t. The pfn of the pte's page is shifted left by PAGE_SIZE |
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| 19 | * bits and is then ORed with the byte offset of the pte within its page. |
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| 20 | * |
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| 21 | * For CONFIG_HIGHMEM4G, the pte_addr_t is 32 bits. 20 for the pfn, 12 for |
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| 22 | * the offset. |
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| 23 | * |
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| 24 | * For CONFIG_HIGHMEM64G, the pte_addr_t is 64 bits. 52 for the pfn, 12 for |
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| 25 | * the offset. |
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| 26 | */ |
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| 27 | #include <linux/mm.h> |
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| 28 | |||
| 29 | static inline void pgtable_add_rmap(struct page * page, struct mm_struct * mm, unsigned long address) |
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| 30 | { |
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| 31 | #ifdef BROKEN_PPC_PTE_ALLOC_ONE |
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| 32 | /* OK, so PPC calls pte_alloc() before mem_map[] is setup ... ;( */ |
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| 33 | extern int mem_init_done; |
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| 34 | |||
| 35 | if (!mem_init_done) |
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| 36 | return; |
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| 37 | #endif |
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| 38 | page->mapping = (void *)mm; |
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| 39 | page->index = address & ~((PTRS_PER_PTE * PAGE_SIZE) - 1); |
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| 40 | inc_page_state(nr_page_table_pages); |
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| 41 | } |
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| 42 | |||
| 43 | static inline void pgtable_remove_rmap(struct page * page) |
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| 44 | { |
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| 45 | page->mapping = NULL; |
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| 46 | page->index = 0; |
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| 47 | dec_page_state(nr_page_table_pages); |
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| 48 | } |
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| 49 | |||
| 50 | static inline struct mm_struct * ptep_to_mm(pte_t * ptep) |
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| 51 | { |
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| 52 | struct page * page = kmap_atomic_to_page(ptep); |
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| 53 | return (struct mm_struct *) page->mapping; |
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| 54 | } |
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| 55 | |||
| 56 | static inline unsigned long ptep_to_address(pte_t * ptep) |
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| 57 | { |
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| 58 | struct page * page = kmap_atomic_to_page(ptep); |
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| 59 | unsigned long low_bits; |
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| 60 | low_bits = ((unsigned long)ptep & ~PAGE_MASK) * PTRS_PER_PTE; |
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| 61 | return page->index + low_bits; |
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| 62 | } |
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| 63 | |||
| 64 | #ifdef CONFIG_HIGHPTE |
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| 65 | static inline pte_addr_t ptep_to_paddr(pte_t *ptep) |
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| 66 | { |
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| 67 | pte_addr_t paddr; |
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| 68 | paddr = ((pte_addr_t)page_to_pfn(kmap_atomic_to_page(ptep))) << PAGE_SHIFT; |
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| 69 | return paddr + (pte_addr_t)((unsigned long)ptep & ~PAGE_MASK); |
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| 70 | } |
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| 71 | #else |
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| 72 | static inline pte_addr_t ptep_to_paddr(pte_t *ptep) |
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| 73 | { |
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| 74 | return (pte_addr_t)ptep; |
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| 75 | } |
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| 76 | #endif |
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| 77 | |||
| 78 | #ifndef CONFIG_HIGHPTE |
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| 79 | static inline pte_t *rmap_ptep_map(pte_addr_t pte_paddr) |
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| 80 | { |
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| 81 | return (pte_t *)pte_paddr; |
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| 82 | } |
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| 83 | |||
| 84 | static inline void rmap_ptep_unmap(pte_t *pte) |
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| 85 | { |
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| 86 | return; |
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| 87 | } |
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| 88 | #endif |
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| 89 | |||
| 90 | #endif /* _GENERIC_RMAP_H */ |