1 /* 2 * PARISC64 Huge TLB page support. 3 * 4 * This parisc implementation is heavily based on the SPARC and x86 code. 5 * 6 * Copyright (C) 2015 Helge Deller <deller@gmx.de> 7 */ 8 9 #include <linux/fs.h> 10 #include <linux/mm.h> 11 #include <linux/hugetlb.h> 12 #include <linux/pagemap.h> 13 #include <linux/sysctl.h> 14 15 #include <asm/mman.h> 16 #include <asm/pgalloc.h> 17 #include <asm/tlb.h> 18 #include <asm/tlbflush.h> 19 #include <asm/cacheflush.h> 20 #include <asm/mmu_context.h> 21 22 23 unsigned long 24 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 25 unsigned long len, unsigned long pgoff, unsigned long flags) 26 { 27 struct hstate *h = hstate_file(file); 28 29 if (len & ~huge_page_mask(h)) 30 return -EINVAL; 31 if (len > TASK_SIZE) 32 return -ENOMEM; 33 34 if (flags & MAP_FIXED) 35 if (prepare_hugepage_range(file, addr, len)) 36 return -EINVAL; 37 38 if (addr) 39 addr = ALIGN(addr, huge_page_size(h)); 40 41 /* we need to make sure the colouring is OK */ 42 return arch_get_unmapped_area(file, addr, len, pgoff, flags); 43 } 44 45 46 pte_t *huge_pte_alloc(struct mm_struct *mm, 47 unsigned long addr, unsigned long sz) 48 { 49 pgd_t *pgd; 50 pud_t *pud; 51 pmd_t *pmd; 52 pte_t *pte = NULL; 53 54 /* We must align the address, because our caller will run 55 * set_huge_pte_at() on whatever we return, which writes out 56 * all of the sub-ptes for the hugepage range. So we have 57 * to give it the first such sub-pte. 58 */ 59 addr &= HPAGE_MASK; 60 61 pgd = pgd_offset(mm, addr); 62 pud = pud_alloc(mm, pgd, addr); 63 if (pud) { 64 pmd = pmd_alloc(mm, pud, addr); 65 if (pmd) 66 pte = pte_alloc_map(mm, NULL, pmd, addr); 67 } 68 return pte; 69 } 70 71 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) 72 { 73 pgd_t *pgd; 74 pud_t *pud; 75 pmd_t *pmd; 76 pte_t *pte = NULL; 77 78 addr &= HPAGE_MASK; 79 80 pgd = pgd_offset(mm, addr); 81 if (!pgd_none(*pgd)) { 82 pud = pud_offset(pgd, addr); 83 if (!pud_none(*pud)) { 84 pmd = pmd_offset(pud, addr); 85 if (!pmd_none(*pmd)) 86 pte = pte_offset_map(pmd, addr); 87 } 88 } 89 return pte; 90 } 91 92 /* Purge data and instruction TLB entries. Must be called holding 93 * the pa_tlb_lock. The TLB purge instructions are slow on SMP 94 * machines since the purge must be broadcast to all CPUs. 95 */ 96 static inline void purge_tlb_entries_huge(struct mm_struct *mm, unsigned long addr) 97 { 98 int i; 99 100 /* We may use multiple physical huge pages (e.g. 2x1 MB) to emulate 101 * Linux standard huge pages (e.g. 2 MB) */ 102 BUILD_BUG_ON(REAL_HPAGE_SHIFT > HPAGE_SHIFT); 103 104 addr &= HPAGE_MASK; 105 addr |= _HUGE_PAGE_SIZE_ENCODING_DEFAULT; 106 107 for (i = 0; i < (1 << (HPAGE_SHIFT-REAL_HPAGE_SHIFT)); i++) { 108 purge_tlb_entries(mm, addr); 109 addr += (1UL << REAL_HPAGE_SHIFT); 110 } 111 } 112 113 /* __set_huge_pte_at() must be called holding the pa_tlb_lock. */ 114 static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr, 115 pte_t *ptep, pte_t entry) 116 { 117 unsigned long addr_start; 118 int i; 119 120 addr &= HPAGE_MASK; 121 addr_start = addr; 122 123 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) { 124 set_pte(ptep, entry); 125 ptep++; 126 127 addr += PAGE_SIZE; 128 pte_val(entry) += PAGE_SIZE; 129 } 130 131 purge_tlb_entries_huge(mm, addr_start); 132 } 133 134 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, 135 pte_t *ptep, pte_t entry) 136 { 137 unsigned long flags; 138 139 purge_tlb_start(flags); 140 __set_huge_pte_at(mm, addr, ptep, entry); 141 purge_tlb_end(flags); 142 } 143 144 145 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, 146 pte_t *ptep) 147 { 148 unsigned long flags; 149 pte_t entry; 150 151 purge_tlb_start(flags); 152 entry = *ptep; 153 __set_huge_pte_at(mm, addr, ptep, __pte(0)); 154 purge_tlb_end(flags); 155 156 return entry; 157 } 158 159 160 void huge_ptep_set_wrprotect(struct mm_struct *mm, 161 unsigned long addr, pte_t *ptep) 162 { 163 unsigned long flags; 164 pte_t old_pte; 165 166 purge_tlb_start(flags); 167 old_pte = *ptep; 168 __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte)); 169 purge_tlb_end(flags); 170 } 171 172 int huge_ptep_set_access_flags(struct vm_area_struct *vma, 173 unsigned long addr, pte_t *ptep, 174 pte_t pte, int dirty) 175 { 176 unsigned long flags; 177 int changed; 178 179 purge_tlb_start(flags); 180 changed = !pte_same(*ptep, pte); 181 if (changed) { 182 __set_huge_pte_at(vma->vm_mm, addr, ptep, pte); 183 } 184 purge_tlb_end(flags); 185 return changed; 186 } 187 188 189 int pmd_huge(pmd_t pmd) 190 { 191 return 0; 192 } 193 194 int pud_huge(pud_t pud) 195 { 196 return 0; 197 } 198