Line data    Source code

       1             : /*
       2             :  * fixmap.h: compile-time virtual memory allocation
       3             :  *
       4             :  * This file is subject to the terms and conditions of the GNU General Public
       5             :  * License.  See the file "COPYING" in the main directory of this archive
       6             :  * for more details.
       7             :  *
       8             :  * Copyright (C) 1998 Ingo Molnar
       9             :  *
      10             :  * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
      11             :  * x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009
      12             :  * Break out common bits to asm-generic by Mark Salter, November 2013
      13             :  */
      14             : 
      15             : #ifndef __ASM_GENERIC_FIXMAP_H
      16             : #define __ASM_GENERIC_FIXMAP_H
      17             : 
      18             : #include <linux/bug.h>
      19             : #include <linux/mm_types.h>
      20             : 
      21             : #define __fix_to_virt(x)        (FIXADDR_TOP - ((x) << PAGE_SHIFT))
      22             : #define __virt_to_fix(x)        ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
      23             : 
      24             : #ifndef __ASSEMBLY__
      25             : /*
      26             :  * 'index to address' translation. If anyone tries to use the idx
      27             :  * directly without translation, we catch the bug with a NULL-deference
      28             :  * kernel oops. Illegal ranges of incoming indices are caught too.
      29             :  */
      30        2534 : static __always_inline unsigned long fix_to_virt(const unsigned int idx)
      31             : {
      32        2534 :         BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
      33        2389 :         return __fix_to_virt(idx);
      34             : }
      35             : 
      36             : static inline unsigned long virt_to_fix(const unsigned long vaddr)
      37             : {
      38             :         BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
      39             :         return __virt_to_fix(vaddr);
      40             : }
      41             : 
      42             : /*
      43             :  * Provide some reasonable defaults for page flags.
      44             :  * Not all architectures use all of these different types and some
      45             :  * architectures use different names.
      46             :  */
      47             : #ifndef FIXMAP_PAGE_NORMAL
      48             : #define FIXMAP_PAGE_NORMAL PAGE_KERNEL
      49             : #endif
      50             : #if !defined(FIXMAP_PAGE_RO) && defined(PAGE_KERNEL_RO)
      51             : #define FIXMAP_PAGE_RO PAGE_KERNEL_RO
      52             : #endif
      53             : #ifndef FIXMAP_PAGE_NOCACHE
      54             : #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE
      55             : #endif
      56             : #ifndef FIXMAP_PAGE_IO
      57             : #define FIXMAP_PAGE_IO PAGE_KERNEL_IO
      58             : #endif
      59             : #ifndef FIXMAP_PAGE_CLEAR
      60             : #define FIXMAP_PAGE_CLEAR __pgprot(0)
      61             : #endif
      62             : 
      63             : #ifndef set_fixmap
      64             : #define set_fixmap(idx, phys)                           \
      65             :         __set_fixmap(idx, phys, FIXMAP_PAGE_NORMAL)
      66             : #endif
      67             : 
      68             : #ifndef clear_fixmap
      69             : #define clear_fixmap(idx)                       \
      70             :         __set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR)
      71             : #endif
      72             : 
      73             : /* Return a pointer with offset calculated */
      74             : #define __set_fixmap_offset(idx, phys, flags)                           \
      75             : ({                                                                      \
      76             :         unsigned long ________addr;                                     \
      77             :         __set_fixmap(idx, phys, flags);                                 \
      78             :         ________addr = fix_to_virt(idx) + ((phys) & (PAGE_SIZE - 1));       \
      79             :         ________addr;                                                   \
      80             : })
      81             : 
      82             : #define set_fixmap_offset(idx, phys) \
      83             :         __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NORMAL)
      84             : 
      85             : /*
      86             :  * Some hardware wants to get fixmapped without caching.
      87             :  */
      88             : #define set_fixmap_nocache(idx, phys) \
      89             :         __set_fixmap(idx, phys, FIXMAP_PAGE_NOCACHE)
      90             : 
      91             : #define set_fixmap_offset_nocache(idx, phys) \
      92             :         __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NOCACHE)
      93             : 
      94             : /*
      95             :  * Some fixmaps are for IO
      96             :  */
      97             : #define set_fixmap_io(idx, phys) \
      98             :         __set_fixmap(idx, phys, FIXMAP_PAGE_IO)
      99             : 
     100             : #define set_fixmap_offset_io(idx, phys) \
     101             :         __set_fixmap_offset(idx, phys, FIXMAP_PAGE_IO)
     102             : 
     103             : #endif /* __ASSEMBLY__ */
     104             : #endif /* __ASM_GENERIC_FIXMAP_H */