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 struct page *kmap_atomic_to_page(void *ptr)
  36 {
  37         return virt_to_page(ptr);
  38 }
  39
  40 void *kmap_atomic(struct page *page)
  41 {
  42         unsigned long paddr;
  43         int type;
  44
  45         preempt_disable();
  46         pagefault_disable();
  47         type = kmap_atomic_idx_push();
  48         paddr = page_to_phys(page);
  49
  50         switch (type) {
  51         /*
  52          * The first 4 primary maps are reserved for architecture code
  53          */
  54         case 0:         return __kmap_atomic_primary(0, paddr, 6);
  55         case 1:         return __kmap_atomic_primary(0, paddr, 7);
  56         case 2:         return __kmap_atomic_primary(0, paddr, 8);
  57         case 3:         return __kmap_atomic_primary(0, paddr, 9);
  58         case 4:         return __kmap_atomic_primary(0, paddr, 10);
  59
  60         case 5 ... 5 + NR_TLB_LINES - 1:
  61                 return __kmap_atomic_secondary(type - 5, paddr);
  62
  63         default:
  64                 BUG();
  65                 return NULL;
  66         }
  67 }
  68 EXPORT_SYMBOL(kmap_atomic);
  69
  70 void __kunmap_atomic(void *kvaddr)
  71 {
  72         int type = kmap_atomic_idx();
  73         switch (type) {
  74         case 0:         __kunmap_atomic_primary(0, 6);  break;
  75         case 1:         __kunmap_atomic_primary(0, 7);  break;
  76         case 2:         __kunmap_atomic_primary(0, 8);  break;
  77         case 3:         __kunmap_atomic_primary(0, 9);  break;
  78         case 4:         __kunmap_atomic_primary(0, 10); break;
  79
  80         case 5 ... 5 + NR_TLB_LINES - 1:
  81                 __kunmap_atomic_secondary(type - 5, kvaddr);
  82                 break;
  83
  84         default:
  85                 BUG();
  86         }
  87         kmap_atomic_idx_pop();
  88         pagefault_enable();
  89         preempt_enable();
  90 }
  91 EXPORT_SYMBOL(__kunmap_atomic);