WSL2-Linux-Kernel/arch/powerpc/mm/book3s32/tlb.c

107 строки
2.9 KiB
C

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