1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * PARISC64 Huge TLB page support. 4 * 5 * This parisc implementation is heavily based on the SPARC and x86 code. 6 * 7 * Copyright (C) 2015 Helge Deller <deller@gmx.de> 8 */ 9 10 #include <linux/fs.h> 11 #include <linux/mm.h> 12 #include <linux/sched/mm.h> 13 #include <linux/hugetlb.h> 14 #include <linux/pagemap.h> 15 #include <linux/sysctl.h> 16 17 #include <asm/mman.h> 18 #include <asm/tlb.h> 19 #include <asm/tlbflush.h> 20 #include <asm/cacheflush.h> 21 #include <asm/mmu_context.h> 22 23 24 unsigned long 25 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 26 unsigned long len, unsigned long pgoff, unsigned long flags) 27 { 28 struct hstate *h = hstate_file(file); 29 30 if (len & ~huge_page_mask(h)) 31 return -EINVAL; 32 if (len > TASK_SIZE) 33 return -ENOMEM; 34 35 if (flags & MAP_FIXED) 36 if (prepare_hugepage_range(file, addr, len)) 37 return -EINVAL; 38 39 if (addr) 40 addr = ALIGN(addr, huge_page_size(h)); 41 42 /* we need to make sure the colouring is OK */ 43 return arch_get_unmapped_area(file, addr, len, pgoff, flags); 44 } 45 46 47 pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, 48 unsigned long addr, unsigned long sz) 49 { 50 pgd_t *pgd; 51 p4d_t *p4d; 52 pud_t *pud; 53 pmd_t *pmd; 54 pte_t *pte = NULL; 55 56 /* We must align the address, because our caller will run 57 * set_huge_pte_at() on whatever we return, which writes out 58 * all of the sub-ptes for the hugepage range. So we have 59 * to give it the first such sub-pte. 60 */ 61 addr &= HPAGE_MASK; 62 63 pgd = pgd_offset(mm, addr); 64 p4d = p4d_offset(pgd, addr); 65 pud = pud_alloc(mm, p4d, addr); 66 if (pud) { 67 pmd = pmd_alloc(mm, pud, addr); 68 if (pmd) 69 pte = pte_alloc_map(mm, pmd, addr); 70 } 71 return pte; 72 } 73 74 pte_t *huge_pte_offset(struct mm_struct *mm, 75 unsigned long addr, unsigned long sz) 76 { 77 pgd_t *pgd; 78 p4d_t *p4d; 79 pud_t *pud; 80 pmd_t *pmd; 81 pte_t *pte = NULL; 82 83 addr &= HPAGE_MASK; 84 85 pgd = pgd_offset(mm, addr); 86 if (!pgd_none(*pgd)) { 87 p4d = p4d_offset(pgd, addr); 88 if (!p4d_none(*p4d)) { 89 pud = pud_offset(p4d, addr); 90 if (!pud_none(*pud)) { 91 pmd = pmd_offset(pud, addr); 92 if (!pmd_none(*pmd)) 93 pte = pte_offset_map(pmd, addr); 94 } 95 } 96 } 97 return pte; 98 } 99 100 /* Purge data and instruction TLB entries. Must be called holding 101 * the pa_tlb_lock. The TLB purge instructions are slow on SMP 102 * machines since the purge must be broadcast to all CPUs. 103 */ 104 static inline void purge_tlb_entries_huge(struct mm_struct *mm, unsigned long addr) 105 { 106 int i; 107 108 /* We may use multiple physical huge pages (e.g. 2x1 MB) to emulate 109 * Linux standard huge pages (e.g. 2 MB) */ 110 BUILD_BUG_ON(REAL_HPAGE_SHIFT > HPAGE_SHIFT); 111 112 addr &= HPAGE_MASK; 113 addr |= _HUGE_PAGE_SIZE_ENCODING_DEFAULT; 114 115 for (i = 0; i < (1 << (HPAGE_SHIFT-REAL_HPAGE_SHIFT)); i++) { 116 purge_tlb_entries(mm, addr); 117 addr += (1UL << REAL_HPAGE_SHIFT); 118 } 119 } 120 121 /* __set_huge_pte_at() must be called holding the pa_tlb_lock. */ 122 static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr, 123 pte_t *ptep, pte_t entry) 124 { 125 unsigned long addr_start; 126 int i; 127 128 addr &= HPAGE_MASK; 129 addr_start = addr; 130 131 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) { 132 set_pte(ptep, entry); 133 ptep++; 134 135 addr += PAGE_SIZE; 136 pte_val(entry) += PAGE_SIZE; 137 } 138 139 purge_tlb_entries_huge(mm, addr_start); 140 } 141 142 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, 143 pte_t *ptep, pte_t entry) 144 { 145 __set_huge_pte_at(mm, addr, ptep, entry); 146 } 147 148 149 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, 150 pte_t *ptep) 151 { 152 pte_t entry; 153 154 entry = *ptep; 155 __set_huge_pte_at(mm, addr, ptep, __pte(0)); 156 157 return entry; 158 } 159 160 161 void huge_ptep_set_wrprotect(struct mm_struct *mm, 162 unsigned long addr, pte_t *ptep) 163 { 164 pte_t old_pte; 165 166 old_pte = *ptep; 167 __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte)); 168 } 169 170 int huge_ptep_set_access_flags(struct vm_area_struct *vma, 171 unsigned long addr, pte_t *ptep, 172 pte_t pte, int dirty) 173 { 174 int changed; 175 struct mm_struct *mm = vma->vm_mm; 176 177 changed = !pte_same(*ptep, pte); 178 if (changed) { 179 __set_huge_pte_at(mm, addr, ptep, pte); 180 } 181 return changed; 182 } 183 184 185 int pmd_huge(pmd_t pmd) 186 { 187 return 0; 188 } 189 190 int pud_huge(pud_t pud) 191 { 192 return 0; 193 } 194