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Diffstat (limited to 'include/asm-generic/fixmap.h')
| -rw-r--r-- | include/asm-generic/fixmap.h | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/include/asm-generic/fixmap.h b/include/asm-generic/fixmap.h new file mode 100644 index 000000000000..5a64ca4621f3 --- /dev/null +++ b/include/asm-generic/fixmap.h @@ -0,0 +1,97 @@ +/* + * 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> + +#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 +#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 */ |
