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
  26 extern void __this_fixmap_does_not_exist(void);
  27
  28 static 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
  35 static 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