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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 | /* * IBM System z Huge TLB Page Support for Kernel. * * Copyright IBM Corp. 2007 * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com> */ #include <linux/mm.h> #include <linux/hugetlb.h> static inline pmd_t __pte_to_pmd(pte_t pte) { pmd_t pmd; /* * Convert encoding pte bits pmd bits * .IR...wrdytp dy..R...I...wr * empty .10...000000 -> 00..0...1...00 * prot-none, clean, old .11...000001 -> 00..1...1...00 * prot-none, clean, young .11...000101 -> 01..1...1...00 * prot-none, dirty, old .10...001001 -> 10..1...1...00 * prot-none, dirty, young .10...001101 -> 11..1...1...00 * read-only, clean, old .11...010001 -> 00..1...1...01 * read-only, clean, young .01...010101 -> 01..1...0...01 * read-only, dirty, old .11...011001 -> 10..1...1...01 * read-only, dirty, young .01...011101 -> 11..1...0...01 * read-write, clean, old .11...110001 -> 00..0...1...11 * read-write, clean, young .01...110101 -> 01..0...0...11 * read-write, dirty, old .10...111001 -> 10..0...1...11 * read-write, dirty, young .00...111101 -> 11..0...0...11 */ if (pte_present(pte)) { pmd_val(pmd) = pte_val(pte) & PAGE_MASK; pmd_val(pmd) |= (pte_val(pte) & _PAGE_READ) >> 4; pmd_val(pmd) |= (pte_val(pte) & _PAGE_WRITE) >> 4; pmd_val(pmd) |= (pte_val(pte) & _PAGE_INVALID) >> 5; pmd_val(pmd) |= (pte_val(pte) & _PAGE_PROTECT); pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10; pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10; } else pmd_val(pmd) = _SEGMENT_ENTRY_INVALID; return pmd; } static inline pte_t __pmd_to_pte(pmd_t pmd) { pte_t pte; /* * Convert encoding pmd bits pte bits * dy..R...I...wr .IR...wrdytp * empty 00..0...1...00 -> .10...001100 * prot-none, clean, old 00..0...1...00 -> .10...000001 * prot-none, clean, young 01..0...1...00 -> .10...000101 * prot-none, dirty, old 10..0...1...00 -> .10...001001 * prot-none, dirty, young 11..0...1...00 -> .10...001101 * read-only, clean, old 00..1...1...01 -> .11...010001 * read-only, clean, young 01..1...1...01 -> .11...010101 * read-only, dirty, old 10..1...1...01 -> .11...011001 * read-only, dirty, young 11..1...1...01 -> .11...011101 * read-write, clean, old 00..0...1...11 -> .10...110001 * read-write, clean, young 01..0...1...11 -> .10...110101 * read-write, dirty, old 10..0...1...11 -> .10...111001 * read-write, dirty, young 11..0...1...11 -> .10...111101 */ if (pmd_present(pmd)) { pte_val(pte) = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN_LARGE; pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT; pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_READ) << 4; pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) << 4; pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) << 5; pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT); pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10; pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10; } else pte_val(pte) = _PAGE_INVALID; return pte; } void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) { pmd_t pmd; pmd = __pte_to_pmd(pte); if (!MACHINE_HAS_HPAGE) { /* Emulated huge ptes loose the dirty and young bit */ pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN; pmd_val(pmd) |= pte_page(pte)[1].index; } else pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE; *(pmd_t *) ptep = pmd; } pte_t huge_ptep_get(pte_t *ptep) { unsigned long origin; pmd_t pmd; pmd = *(pmd_t *) ptep; if (!MACHINE_HAS_HPAGE && pmd_present(pmd)) { origin = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN; pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN; pmd_val(pmd) |= *(unsigned long *) origin; /* Emulated huge ptes are young and dirty by definition */ pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG | _SEGMENT_ENTRY_DIRTY; } return __pmd_to_pte(pmd); } pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { pmd_t *pmdp = (pmd_t *) ptep; pte_t pte = huge_ptep_get(ptep); pmdp_flush_direct(mm, addr, pmdp); pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY; return pte; } int arch_prepare_hugepage(struct page *page) { unsigned long addr = page_to_phys(page); pte_t pte; pte_t *ptep; int i; if (MACHINE_HAS_HPAGE) return 0; ptep = (pte_t *) pte_alloc_one(&init_mm, addr); if (!ptep) return -ENOMEM; pte_val(pte) = addr; for (i = 0; i < PTRS_PER_PTE; i++) { set_pte_at(&init_mm, addr + i * PAGE_SIZE, ptep + i, pte); pte_val(pte) += PAGE_SIZE; } page[1].index = (unsigned long) ptep; return 0; } void arch_release_hugepage(struct page *page) { pte_t *ptep; if (MACHINE_HAS_HPAGE) return; ptep = (pte_t *) page[1].index; if (!ptep) return; clear_table((unsigned long *) ptep, _PAGE_INVALID, PTRS_PER_PTE * sizeof(pte_t)); page_table_free(&init_mm, (unsigned long *) ptep); page[1].index = 0; } pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz) { pgd_t *pgdp; pud_t *pudp; pmd_t *pmdp = NULL; pgdp = pgd_offset(mm, addr); pudp = pud_alloc(mm, pgdp, addr); if (pudp) pmdp = pmd_alloc(mm, pudp, addr); return (pte_t *) pmdp; } pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) { pgd_t *pgdp; pud_t *pudp; pmd_t *pmdp = NULL; pgdp = pgd_offset(mm, addr); if (pgd_present(*pgdp)) { pudp = pud_offset(pgdp, addr); if (pud_present(*pudp)) pmdp = pmd_offset(pudp, addr); } return (pte_t *) pmdp; } int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) { return 0; } struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) { return ERR_PTR(-EINVAL); } int pmd_huge(pmd_t pmd) { if (!MACHINE_HAS_HPAGE) return 0; return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE); } int pud_huge(pud_t pud) { return 0; } struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmdp, int write) { struct page *page; if (!MACHINE_HAS_HPAGE) return NULL; page = pmd_page(*pmdp); if (page) page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT); return page; } |