108 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			108 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-or-later
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| /*
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|  * This file contains the routines for TLB flushing.
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|  * On machines where the MMU uses a hash table to store virtual to
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|  * physical translations, these routines flush entries from the
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|  * hash table also.
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|  *  -- paulus
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|  *
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|  *  Derived from arch/ppc/mm/init.c:
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|  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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|  *
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|  *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
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|  *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
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|  *    Copyright (C) 1996 Paul Mackerras
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|  *
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|  *  Derived from "arch/i386/mm/init.c"
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|  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
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|  */
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| 
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| #include <linux/kernel.h>
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| #include <linux/mm.h>
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| #include <linux/init.h>
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| #include <linux/highmem.h>
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| #include <linux/pagemap.h>
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| #include <linux/export.h>
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| 
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| #include <asm/tlbflush.h>
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| #include <asm/tlb.h>
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| 
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| #include <mm/mmu_decl.h>
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| 
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| /*
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|  * TLB flushing:
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|  *
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|  *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
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|  *  - flush_tlb_page(vma, vmaddr) flushes one page
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|  *  - flush_tlb_range(vma, start, end) flushes a range of pages
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|  *  - flush_tlb_kernel_range(start, end) flushes kernel pages
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|  *
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|  * since the hardware hash table functions as an extension of the
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|  * tlb as far as the linux tables are concerned, flush it too.
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|  *    -- Cort
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|  */
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| 
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| /*
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|  * For each address in the range, find the pte for the address
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|  * and check _PAGE_HASHPTE bit; if it is set, find and destroy
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|  * the corresponding HPTE.
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|  */
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| void hash__flush_range(struct mm_struct *mm, unsigned long start, unsigned long end)
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| {
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| 	pmd_t *pmd;
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| 	unsigned long pmd_end;
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| 	int count;
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| 	unsigned int ctx = mm->context.id;
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| 
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| 	start &= PAGE_MASK;
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| 	if (start >= end)
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| 		return;
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| 	end = (end - 1) | ~PAGE_MASK;
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| 	pmd = pmd_off(mm, start);
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| 	for (;;) {
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| 		pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1;
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| 		if (pmd_end > end)
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| 			pmd_end = end;
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| 		if (!pmd_none(*pmd)) {
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| 			count = ((pmd_end - start) >> PAGE_SHIFT) + 1;
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| 			flush_hash_pages(ctx, start, pmd_val(*pmd), count);
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| 		}
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| 		if (pmd_end == end)
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| 			break;
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| 		start = pmd_end + 1;
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| 		++pmd;
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| 	}
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| }
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| EXPORT_SYMBOL(hash__flush_range);
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| 
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| /*
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|  * Flush all the (user) entries for the address space described by mm.
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|  */
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| void hash__flush_tlb_mm(struct mm_struct *mm)
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| {
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| 	struct vm_area_struct *mp;
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| 	VMA_ITERATOR(vmi, mm, 0);
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| 
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| 	/*
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| 	 * It is safe to iterate the vmas when called from dup_mmap,
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| 	 * holding mmap_lock.  It would also be safe from unmap_region
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| 	 * or exit_mmap, but not from vmtruncate on SMP - but it seems
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| 	 * dup_mmap is the only SMP case which gets here.
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| 	 */
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| 	for_each_vma(vmi, mp)
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| 		hash__flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
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| }
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| EXPORT_SYMBOL(hash__flush_tlb_mm);
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| 
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| void hash__flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
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| {
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| 	struct mm_struct *mm;
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| 	pmd_t *pmd;
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| 
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| 	mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
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| 	pmd = pmd_off(mm, vmaddr);
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| 	if (!pmd_none(*pmd))
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| 		flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1);
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| }
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| EXPORT_SYMBOL(hash__flush_tlb_page);
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