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  */
  20 unsigned 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  */
  29 void 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 }