LXR linux/arch/arm/include/asm/fixmap.h

   1#ifndef _ASM_FIXMAP_H
   2#define _ASM_FIXMAP_H
   3
   4/*
   5 * Nothing too fancy for now.
   6 *
   7 * On ARM we already have well known fixed virtual addresses imposed by
   8 * the architecture such as the vector page which is located at 0xffff0000,
   9 * therefore a second level page table is already allocated covering
  10 * 0xfff00000 upwards.
  11 *
  12 * The cache flushing code in proc-xscale.S uses the virtual area between
  13 * 0xfffe0000 and 0xfffeffff.
  14 */
  15
  16#define FIXADDR_START           0xfff00000UL
  17#define FIXADDR_TOP             0xfffe0000UL
  18#define FIXADDR_SIZE            (FIXADDR_TOP - FIXADDR_START)
  19
  20#define FIX_KMAP_BEGIN          0
  21#define FIX_KMAP_END            (FIXADDR_SIZE >> PAGE_SHIFT)
  22
  23#define __fix_to_virt(x)        (FIXADDR_START + ((x) << PAGE_SHIFT))
  24#define __virt_to_fix(x)        (((x) - FIXADDR_START) >> PAGE_SHIFT)
  25
  26extern void __this_fixmap_does_not_exist(void);
  27
  28static inline unsigned long fix_to_virt(const unsigned int idx)
  29{
  30        if (idx >= FIX_KMAP_END)
  31                __this_fixmap_does_not_exist();
  32        return __fix_to_virt(idx);
  33}
  34
  35static inline unsigned int virt_to_fix(const unsigned long vaddr)
  36{
  37        BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
  38        return __virt_to_fix(vaddr);
  39}
  40
  41#endif
  42