1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * This file contains the routines for TLB flushing. 4 * On machines where the MMU uses a hash table to store virtual to 5 * physical translations, these routines flush entries from the 6 * hash table also. 7 * -- paulus 8 * 9 * Derived from arch/ppc/mm/init.c: 10 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 11 * 12 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) 13 * and Cort Dougan (PReP) (cort@cs.nmt.edu) 14 * Copyright (C) 1996 Paul Mackerras 15 * 16 * Derived from "arch/i386/mm/init.c" 17 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 18 */ 19 20 #include <linux/kernel.h> 21 #include <linux/mm.h> 22 #include <linux/init.h> 23 #include <linux/highmem.h> 24 #include <linux/pagemap.h> 25 #include <linux/export.h> 26 27 #include <asm/tlbflush.h> 28 #include <asm/tlb.h> 29 30 #include <mm/mmu_decl.h> 31 32 /* 33 * TLB flushing: 34 * 35 * - flush_tlb_mm(mm) flushes the specified mm context TLB's 36 * - flush_tlb_page(vma, vmaddr) flushes one page 37 * - flush_tlb_range(vma, start, end) flushes a range of pages 38 * - flush_tlb_kernel_range(start, end) flushes kernel pages 39 * 40 * since the hardware hash table functions as an extension of the 41 * tlb as far as the linux tables are concerned, flush it too. 42 * -- Cort 43 */ 44 45 /* 46 * For each address in the range, find the pte for the address 47 * and check _PAGE_HASHPTE bit; if it is set, find and destroy 48 * the corresponding HPTE. 49 */ 50 void hash__flush_range(struct mm_struct *mm, unsigned long start, unsigned long end) 51 { 52 pmd_t *pmd; 53 unsigned long pmd_end; 54 int count; 55 unsigned int ctx = mm->context.id; 56 57 start &= PAGE_MASK; 58 if (start >= end) 59 return; 60 end = (end - 1) | ~PAGE_MASK; 61 pmd = pmd_off(mm, start); 62 for (;;) { 63 pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1; 64 if (pmd_end > end) 65 pmd_end = end; 66 if (!pmd_none(*pmd)) { 67 count = ((pmd_end - start) >> PAGE_SHIFT) + 1; 68 flush_hash_pages(ctx, start, pmd_val(*pmd), count); 69 } 70 if (pmd_end == end) 71 break; 72 start = pmd_end + 1; 73 ++pmd; 74 } 75 } 76 EXPORT_SYMBOL(hash__flush_range); 77 78 /* 79 * Flush all the (user) entries for the address space described by mm. 80 */ 81 void hash__flush_tlb_mm(struct mm_struct *mm) 82 { 83 struct vm_area_struct *mp; 84 VMA_ITERATOR(vmi, mm, 0); 85 86 /* 87 * It is safe to iterate the vmas when called from dup_mmap, 88 * holding mmap_lock. It would also be safe from unmap_region 89 * or exit_mmap, but not from vmtruncate on SMP - but it seems 90 * dup_mmap is the only SMP case which gets here. 91 */ 92 for_each_vma(vmi, mp) 93 hash__flush_range(mp->vm_mm, mp->vm_start, mp->vm_end); 94 } 95 EXPORT_SYMBOL(hash__flush_tlb_mm); 96 97 void hash__flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr) 98 { 99 struct mm_struct *mm; 100 pmd_t *pmd; 101 102 mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm; 103 pmd = pmd_off(mm, vmaddr); 104 if (!pmd_none(*pmd)) 105 flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1); 106 } 107 EXPORT_SYMBOL(hash__flush_tlb_page); 108