LXR linux/arch/mn10300/mm/mmu-context.c

   1/* MN10300 MMU context allocation and management
   2 *
   3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public Licence
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the Licence, or (at your option) any later version.
  10 */
  11#include <linux/sched.h>
  12#include <linux/mm.h>
  13#include <asm/mmu_context.h>
  14#include <asm/tlbflush.h>
  15
  16/*
  17 * list of the MMU contexts last allocated on each CPU
  18 */
  19unsigned long mmu_context_cache[NR_CPUS] = {
  20        [0 ... NR_CPUS - 1] = MMU_CONTEXT_FIRST_VERSION * 2 - 1,
  21};
  22
  23/*
  24 * flush the specified TLB entry
  25 */
  26void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
  27{
  28        unsigned long pteu, cnx, flags;
  29
  30        addr &= PAGE_MASK;
  31
  32        /* make sure the context doesn't migrate and defend against
  33         * interference from vmalloc'd regions */
  34        local_irq_save(flags);
  35
  36        cnx = mm_context(vma->vm_mm);
  37
  38        if (cnx != MMU_NO_CONTEXT) {
  39                pteu = addr | (cnx & 0x000000ffUL);
  40                IPTEU = pteu;
  41                DPTEU = pteu;
  42                if (IPTEL & xPTEL_V)
  43                        IPTEL = 0;
  44                if (DPTEL & xPTEL_V)
  45                        DPTEL = 0;
  46        }
  47
  48        local_irq_restore(flags);
  49}
  50
  51/*
  52 * preemptively set a TLB entry
  53 */
  54void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
  55{
  56        unsigned long pteu, ptel, cnx, flags;
  57
  58        addr &= PAGE_MASK;
  59        ptel = pte_val(pte) & ~(xPTEL_UNUSED1 | xPTEL_UNUSED2);
  60
  61        /* make sure the context doesn't migrate and defend against
  62         * interference from vmalloc'd regions */
  63        local_irq_save(flags);
  64
  65        cnx = mm_context(vma->vm_mm);
  66
  67        if (cnx != MMU_NO_CONTEXT) {
  68                pteu = addr | (cnx & 0x000000ffUL);
  69                if (!(pte_val(pte) & _PAGE_NX)) {
  70                        IPTEU = pteu;
  71                        if (IPTEL & xPTEL_V)
  72                                IPTEL = ptel;
  73                }
  74                DPTEU = pteu;
  75                if (DPTEL & xPTEL_V)
  76                        DPTEL = ptel;
  77        }
  78
  79        local_irq_restore(flags);
  80}
  81