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#ifdef CONFIG_MN10300_TLB_USE_PIDR
  17/*
  18 * list of the MMU contexts last allocated on each CPU
  19 */
  20unsigned long mmu_context_cache[NR_CPUS] = {
  21        [0 ... NR_CPUS - 1] =
  22        MMU_CONTEXT_FIRST_VERSION * 2 - (1 - MMU_CONTEXT_TLBPID_LOCK_NR),
  23};
  24#endif /* CONFIG_MN10300_TLB_USE_PIDR */
  25
  26/*
  27 * preemptively set a TLB entry
  28 */
  29void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
  30{
  31        unsigned long pteu, ptel, cnx, flags;
  32        pte_t pte = *ptep;
  33
  34        addr &= PAGE_MASK;
  35        ptel = pte_val(pte) & ~(xPTEL_UNUSED1 | xPTEL_UNUSED2);
  36
  37        /* make sure the context doesn't migrate and defend against
  38         * interference from vmalloc'd regions */
  39        local_irq_save(flags);
  40
  41        cnx = ~MMU_NO_CONTEXT;
  42#ifdef CONFIG_MN10300_TLB_USE_PIDR
  43        cnx = mm_context(vma->vm_mm);
  44#endif
  45
  46        if (cnx != MMU_NO_CONTEXT) {
  47                pteu = addr;
  48#ifdef CONFIG_MN10300_TLB_USE_PIDR
  49                pteu |= cnx & MMU_CONTEXT_TLBPID_MASK;
  50#endif
  51                if (!(pte_val(pte) & _PAGE_NX)) {
  52                        IPTEU = pteu;
  53                        if (IPTEL & xPTEL_V)
  54                                IPTEL = ptel;
  55                }
  56                DPTEU = pteu;
  57                if (DPTEL & xPTEL_V)
  58                        DPTEL = ptel;
  59        }
  60
  61        local_irq_restore(flags);
  62}
  63