text: /*
   * Fixmap support for Hexagon - enough to support highmem features
   *
   * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 and
   * only version 2 as published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   * 02110-1301, USA.
   */
  
  #ifndef _ASM_FIXMAP_H
  #define _ASM_FIXMAP_H
  
  /*
   * A lot of the fixmap info is already in mem-layout.h
   */
  #include <asm/mem-layout.h>
  
  /*
   * Full fixmap support involves set_fixmap() functions, but
   * these may not be needed if all we're after is an area for
   * highmem kernel mappings.
   */
  #define	__fix_to_virt(x)	(FIXADDR_TOP - ((x) << PAGE_SHIFT))
  #define	__virt_to_fix(x)	((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
  
  extern void __this_fixmap_does_not_exist(void);
  
  /**
   * fix_to_virt -- "index to address" translation.
   *
   * If anyone tries to use the idx directly without translation,
   * we catch the bug with a NULL-deference kernel oops. Illegal
   * ranges of incoming indices are caught too.
   */
  static inline unsigned long fix_to_virt(const unsigned int idx)
  {
  	/*
  	 * This branch gets completely eliminated after inlining,
  	 * except when someone tries to use fixaddr indices in an
  	 * illegal way. (such as mixing up address types or using
  	 * out-of-range indices).
  	 *
  	 * If it doesn't get removed, the linker will complain
  	 * loudly with a reasonably clear error message..
  	 */
  	if (idx >= __end_of_fixed_addresses)
  		__this_fixmap_does_not_exist();
  
  	return __fix_to_virt(idx);
  }
  
  static inline unsigned long virt_to_fix(const unsigned long vaddr)
  {
  	BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
  	return __virt_to_fix(vaddr);
  }
  
  #define kmap_get_fixmap_pte(vaddr) \
  	pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), \
  				(vaddr)), (vaddr)), (vaddr))
  
  #endif
  