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/*
* 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)
#define set_fixmap_offset_io(idx, phys) \
__set_fixmap_offset(idx, phys, FIXMAP_PAGE_IO)
#endif /* __ASSEMBLY__ */
#endif /* __ASM_GENERIC_FIXMAP_H */
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