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/pgalloc.h> 19 #include <asm/tlb.h> 20 #include <asm/tlbflush.h> 21 #include <asm/cacheflush.h> 22 #include <asm/mmu_context.h> 23 24 25 unsigned long 26 hugetlb_get_unmapped_area(struct file *file, unsigned long addr, 27 unsigned long len, unsigned long pgoff, unsigned long flags) 28 { 29 struct hstate *h = hstate_file(file); 30 31 if (len & ~huge_page_mask(h)) 32 return -EINVAL; 33 if (len > TASK_SIZE) 34 return -ENOMEM; 35 36 if (flags & MAP_FIXED) 37 if (prepare_hugepage_range(file, addr, len)) 38 return -EINVAL; 39 40 if (addr) 41 addr = ALIGN(addr, huge_page_size(h)); 42 43 /* we need to make sure the colouring is OK */ 44 return arch_get_unmapped_area(file, addr, len, pgoff, flags); 45 } 46 47 48 pte_t *huge_pte_alloc(struct mm_struct *mm, 49 unsigned long addr, unsigned long sz) 50 { 51 pgd_t *pgd; 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 pud = pud_alloc(mm, pgd, addr); 65 if (pud) { 66 pmd = pmd_alloc(mm, pud, addr); 67 if (pmd) 68 pte = pte_alloc_map(mm, pmd, addr); 69 } 70 return pte; 71 } 72 73 pte_t *huge_pte_offset(struct mm_struct *mm, 74 unsigned long addr, unsigned long sz) 75 { 76 pgd_t *pgd; 77 pud_t *pud; 78 pmd_t *pmd; 79 pte_t *pte = NULL; 80 81 addr &= HPAGE_MASK; 82 83 pgd = pgd_offset(mm, addr); 84 if (!pgd_none(*pgd)) { 85 pud = pud_offset(pgd, addr); 86 if (!pud_none(*pud)) { 87 pmd = pmd_offset(pud, addr); 88 if (!pmd_none(*pmd)) 89 pte = pte_offset_map(pmd, addr); 90 } 91 } 92 return pte; 93 } 94 95 /* Purge data and instruction TLB entries. Must be called holding 96 * the pa_tlb_lock. The TLB purge instructions are slow on SMP 97 * machines since the purge must be broadcast to all CPUs. 98 */ 99 static inline void purge_tlb_entries_huge(struct mm_struct *mm, unsigned long addr) 100 { 101 int i; 102 103 /* We may use multiple physical huge pages (e.g. 2x1 MB) to emulate 104 * Linux standard huge pages (e.g. 2 MB) */ 105 BUILD_BUG_ON(REAL_HPAGE_SHIFT > HPAGE_SHIFT); 106 107 addr &= HPAGE_MASK; 108 addr |= _HUGE_PAGE_SIZE_ENCODING_DEFAULT; 109 110 for (i = 0; i < (1 << (HPAGE_SHIFT-REAL_HPAGE_SHIFT)); i++) { 111 purge_tlb_entries(mm, addr); 112 addr += (1UL << REAL_HPAGE_SHIFT); 113 } 114 } 115 116 /* __set_huge_pte_at() must be called holding the pa_tlb_lock. */ 117 static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr, 118 pte_t *ptep, pte_t entry) 119 { 120 unsigned long addr_start; 121 int i; 122 123 addr &= HPAGE_MASK; 124 addr_start = addr; 125 126 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) { 127 set_pte(ptep, entry); 128 ptep++; 129 130 addr += PAGE_SIZE; 131 pte_val(entry) += PAGE_SIZE; 132 } 133 134 purge_tlb_entries_huge(mm, addr_start); 135 } 136 137 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, 138 pte_t *ptep, pte_t entry) 139 { 140 unsigned long flags; 141 142 spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags); 143 __set_huge_pte_at(mm, addr, ptep, entry); 144 spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags); 145 } 146 147 148 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, 149 pte_t *ptep) 150 { 151 unsigned long flags; 152 pte_t entry; 153 154 spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags); 155 entry = *ptep; 156 __set_huge_pte_at(mm, addr, ptep, __pte(0)); 157 spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags); 158 159 return entry; 160 } 161 162 163 void huge_ptep_set_wrprotect(struct mm_struct *mm, 164 unsigned long addr, pte_t *ptep) 165 { 166 unsigned long flags; 167 pte_t old_pte; 168 169 spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags); 170 old_pte = *ptep; 171 __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte)); 172 spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags); 173 } 174 175 int huge_ptep_set_access_flags(struct vm_area_struct *vma, 176 unsigned long addr, pte_t *ptep, 177 pte_t pte, int dirty) 178 { 179 unsigned long flags; 180 int changed; 181 struct mm_struct *mm = vma->vm_mm; 182 183 spin_lock_irqsave(pgd_spinlock((mm)->pgd), flags); 184 changed = !pte_same(*ptep, pte); 185 if (changed) { 186 __set_huge_pte_at(mm, addr, ptep, pte); 187 } 188 spin_unlock_irqrestore(pgd_spinlock((mm)->pgd), flags); 189 return changed; 190 } 191 192 193 int pmd_huge(pmd_t pmd) 194 { 195 return 0; 196 } 197 198 int pud_huge(pud_t pud) 199 { 200 return 0; 201 } 202