arch/frv/mm/highmem.c

   1 /* highmem.c: arch-specific highmem stuff
   2  *
   3  * Copyright (C) 2004 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 License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11 #include <linux/highmem.h>
  12 #include <linux/module.h>
  13
  14 void *kmap(struct page *page)
  15 {
  16         might_sleep();
  17         if (!PageHighMem(page))
  18                 return page_address(page);
  19         return kmap_high(page);
  20 }
  21
  22 EXPORT_SYMBOL(kmap);
  23
  24 void kunmap(struct page *page)
  25 {
  26         if (in_interrupt())
  27                 BUG();
  28         if (!PageHighMem(page))
  29                 return;
  30         kunmap_high(page);
  31 }
  32
  33 EXPORT_SYMBOL(kunmap);
  34
  35 void *kmap_atomic(struct page *page)
  36 {
  37         unsigned long paddr;
  38         int type;
  39
  40         preempt_disable();
  41         pagefault_disable();
  42         type = kmap_atomic_idx_push();
  43         paddr = page_to_phys(page);
  44
  45         switch (type) {
  46         /*
  47          * The first 4 primary maps are reserved for architecture code
  48          */
  49         case 0:         return __kmap_atomic_primary(0, paddr, 6);
  50         case 1:         return __kmap_atomic_primary(0, paddr, 7);
  51         case 2:         return __kmap_atomic_primary(0, paddr, 8);
  52         case 3:         return __kmap_atomic_primary(0, paddr, 9);
  53         case 4:         return __kmap_atomic_primary(0, paddr, 10);
  54
  55         case 5 ... 5 + NR_TLB_LINES - 1:
  56                 return __kmap_atomic_secondary(type - 5, paddr);
  57
  58         default:
  59                 BUG();
  60                 return NULL;
  61         }
  62 }
  63 EXPORT_SYMBOL(kmap_atomic);
  64
  65 void __kunmap_atomic(void *kvaddr)
  66 {
  67         int type = kmap_atomic_idx();
  68         switch (type) {
  69         case 0:         __kunmap_atomic_primary(0, 6);  break;
  70         case 1:         __kunmap_atomic_primary(0, 7);  break;
  71         case 2:         __kunmap_atomic_primary(0, 8);  break;
  72         case 3:         __kunmap_atomic_primary(0, 9);  break;
  73         case 4:         __kunmap_atomic_primary(0, 10); break;
  74
  75         case 5 ... 5 + NR_TLB_LINES - 1:
  76                 __kunmap_atomic_secondary(type - 5, kvaddr);
  77                 break;
  78
  79         default:
  80                 BUG();
  81         }
  82         kmap_atomic_idx_pop();
  83         pagefault_enable();
  84         preempt_enable();
  85 }
  86 EXPORT_SYMBOL(__kunmap_atomic);