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1/*2 * fixmap.h: compile-time virtual memory allocation3 *4 * This file is subject to the terms and conditions of the GNU General Public5 * License. See the file "COPYING" in the main directory of this archive6 * for more details.7 *8 * Copyright (C) 1998 Ingo Molnar9 *10 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 199911 * x86_32 and x86_64 integration by Gustavo F. Padovan, February 200912 * Break out common bits to asm-generic by Mark Salter, November 201313 */14 15#ifndef __ASM_GENERIC_FIXMAP_H16#define __ASM_GENERIC_FIXMAP_H17 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 idx27 * directly without translation, we catch the bug with a NULL-deference28 * kernel oops. Illegal ranges of incoming indices are caught too.29 */30static __always_inline unsigned long fix_to_virt(const unsigned int idx)31{32 BUILD_BUG_ON(idx >= __end_of_fixed_addresses);33 return __fix_to_virt(idx);34}35 36static 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 some45 * architectures use different names.46 */47#ifndef FIXMAP_PAGE_NORMAL48#define FIXMAP_PAGE_NORMAL PAGE_KERNEL49#endif50#if !defined(FIXMAP_PAGE_RO) && defined(PAGE_KERNEL_RO)51#define FIXMAP_PAGE_RO PAGE_KERNEL_RO52#endif53#ifndef FIXMAP_PAGE_NOCACHE54#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE55#endif56#ifndef FIXMAP_PAGE_IO57#define FIXMAP_PAGE_IO PAGE_KERNEL_IO58#endif59#ifndef FIXMAP_PAGE_CLEAR60#define FIXMAP_PAGE_CLEAR __pgprot(0)61#endif62 63#ifndef set_fixmap64#define set_fixmap(idx, phys) \65 __set_fixmap(idx, phys, FIXMAP_PAGE_NORMAL)66#endif67 68#ifndef clear_fixmap69#define clear_fixmap(idx) \70 __set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR)71#endif72 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 IO96 */97#define set_fixmap_io(idx, phys) \98 __set_fixmap(idx, phys, FIXMAP_PAGE_IO)99 100#endif /* __ASSEMBLY__ */101#endif /* __ASM_GENERIC_FIXMAP_H */102