/* * fixmap.h: compile-time virtual memory allocation * * This file is subject to the terms and conditions of the GNU General Public * License.  See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1998 Ingo Molnar * * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 * x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009 * Break out common bits to asm-generic by Mark Salter, November 2013 */ #ifndef __ASM_GENERIC_FIXMAP_H#define __ASM_GENERIC_FIXMAP_H #include <linux/bug.h>#include <linux/mm_types.h> #define __fix_to_virt(x)	(FIXADDR_TOP - ((x) << PAGE_SHIFT))#define __virt_to_fix(x)	((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) #ifndef __ASSEMBLY__/* * '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 __always_inline unsigned long fix_to_virt(const unsigned int idx){	BUILD_BUG_ON(idx >= __end_of_fixed_addresses);	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);} /* * Provide some reasonable defaults for page flags. * Not all architectures use all of these different types and some * architectures use different names. */#ifndef FIXMAP_PAGE_NORMAL#define FIXMAP_PAGE_NORMAL PAGE_KERNEL#endif#if !defined(FIXMAP_PAGE_RO) && defined(PAGE_KERNEL_RO)#define FIXMAP_PAGE_RO PAGE_KERNEL_RO#endif#ifndef FIXMAP_PAGE_NOCACHE#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE#endif#ifndef FIXMAP_PAGE_IO#define FIXMAP_PAGE_IO PAGE_KERNEL_IO#endif#ifndef FIXMAP_PAGE_CLEAR#define FIXMAP_PAGE_CLEAR __pgprot(0)#endif #ifndef set_fixmap#define set_fixmap(idx, phys)				\	__set_fixmap(idx, phys, FIXMAP_PAGE_NORMAL)#endif #ifndef clear_fixmap#define clear_fixmap(idx)			\	__set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR)#endif /* Return a pointer with offset calculated */#define __set_fixmap_offset(idx, phys, flags)				\({									\	unsigned long ________addr;					\	__set_fixmap(idx, phys, flags);					\	________addr = fix_to_virt(idx) + ((phys) & (PAGE_SIZE - 1));	\	________addr;							\}) #define set_fixmap_offset(idx, phys) \	__set_fixmap_offset(idx, phys, FIXMAP_PAGE_NORMAL) /* * Some hardware wants to get fixmapped without caching. */#define set_fixmap_nocache(idx, phys) \	__set_fixmap(idx, phys, FIXMAP_PAGE_NOCACHE) #define set_fixmap_offset_nocache(idx, phys) \	__set_fixmap_offset(idx, phys, FIXMAP_PAGE_NOCACHE) /* * Some fixmaps are for IO */#define set_fixmap_io(idx, phys) \	__set_fixmap(idx, phys, FIXMAP_PAGE_IO) #endif /* __ASSEMBLY__ */#endif /* __ASM_GENERIC_FIXMAP_H */