1 /* 2 * fixmap.h: compile-time virtual memory allocation 3 * 4 * This file is subject to the terms and conditions of the GNU General Public 5 * License. See the file "COPYING" in the main directory of this archive 6 * for more details. 7 * 8 * Copyright (C) 1998 Ingo Molnar 9 * 10 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 11 * x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009 12 * Break out common bits to asm-generic by Mark Salter, November 2013 13 */ 14 15 #ifndef __ASM_GENERIC_FIXMAP_H 16 #define __ASM_GENERIC_FIXMAP_H 17 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 idx 27 * directly without translation, we catch the bug with a NULL-deference 28 * kernel oops. Illegal ranges of incoming indices are caught too. 29 */ 30 static __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 36 static 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 some 45 * architectures use different names. 46 */ 47 #ifndef FIXMAP_PAGE_NORMAL 48 #define FIXMAP_PAGE_NORMAL PAGE_KERNEL 49 #endif 50 #if !defined(FIXMAP_PAGE_RO) && defined(PAGE_KERNEL_RO) 51 #define FIXMAP_PAGE_RO PAGE_KERNEL_RO 52 #endif 53 #ifndef FIXMAP_PAGE_NOCACHE 54 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE 55 #endif 56 #ifndef FIXMAP_PAGE_IO 57 #define FIXMAP_PAGE_IO PAGE_KERNEL_IO 58 #endif 59 #ifndef FIXMAP_PAGE_CLEAR 60 #define FIXMAP_PAGE_CLEAR __pgprot(0) 61 #endif 62 63 #ifndef set_fixmap 64 #define set_fixmap(idx, phys) \ 65 __set_fixmap(idx, phys, FIXMAP_PAGE_NORMAL) 66 #endif 67 68 #ifndef clear_fixmap 69 #define clear_fixmap(idx) \ 70 __set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR) 71 #endif 72 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 IO 96 */ 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