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  */
  19 unsigned 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  */
  26 void 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  */
  54 void 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 }