arch/x86/mm/iomap_32.c

   1 /*
   2  * Copyright © 2008 Ingo Molnar
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  17  */
  18
  19 #include <asm/iomap.h>
  20 #include <linux/module.h>
  21
  22 /* Map 'pfn' using fixed map 'type' and protections 'prot'
  23  */
  24 void *
  25 iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
  26 {
  27         enum fixed_addresses idx;
  28         unsigned long vaddr;
  29
  30         pagefault_disable();
  31
  32         idx = type + KM_TYPE_NR*smp_processor_id();
  33         vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
  34         set_pte(kmap_pte-idx, pfn_pte(pfn, prot));
  35         arch_flush_lazy_mmu_mode();
  36
  37         return (void*) vaddr;
  38 }
  39 EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
  40
  41 void
  42 iounmap_atomic(void *kvaddr, enum km_type type)
  43 {
  44         unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
  45         enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
  46
  47         /*
  48          * Force other mappings to Oops if they'll try to access this pte
  49          * without first remap it.  Keeping stale mappings around is a bad idea
  50          * also, in case the page changes cacheability attributes or becomes
  51          * a protected page in a hypervisor.
  52          */
  53         if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx))
  54                 kpte_clear_flush(kmap_pte-idx, vaddr);
  55
  56         arch_flush_lazy_mmu_mode();
  57         pagefault_enable();
  58 }
  59 EXPORT_SYMBOL_GPL(iounmap_atomic);