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 20 #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) 21 #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) 22 23 #ifndef __ASSEMBLY__ 24 /* 25 * 'index to address' translation. If anyone tries to use the idx 26 * directly without translation, we catch the bug with a NULL-deference 27 * kernel oops. Illegal ranges of incoming indices are caught too. 28 */ 29 static __always_inline unsigned long fix_to_virt(const unsigned int idx) 30 { 31 BUILD_BUG_ON(idx >= __end_of_fixed_addresses); 32 return __fix_to_virt(idx); 33 } 34 35 static inline unsigned long virt_to_fix(const unsigned long vaddr) 36 { 37 BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); 38 return __virt_to_fix(vaddr); 39 } 40 41 /* 42 * Provide some reasonable defaults for page flags. 43 * Not all architectures use all of these different types and some 44 * architectures use different names. 45 */ 46 #ifndef FIXMAP_PAGE_NORMAL 47 #define FIXMAP_PAGE_NORMAL PAGE_KERNEL 48 #endif 49 #ifndef FIXMAP_PAGE_NOCACHE 50 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE 51 #endif 52 #ifndef FIXMAP_PAGE_IO 53 #define FIXMAP_PAGE_IO PAGE_KERNEL_IO 54 #endif 55 #ifndef FIXMAP_PAGE_CLEAR 56 #define FIXMAP_PAGE_CLEAR __pgprot(0) 57 #endif 58 59 #ifndef set_fixmap 60 #define set_fixmap(idx, phys) \ 61 __set_fixmap(idx, phys, FIXMAP_PAGE_NORMAL) 62 #endif 63 64 #ifndef clear_fixmap 65 #define clear_fixmap(idx) \ 66 __set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR) 67 #endif 68 69 /* Return a pointer with offset calculated */ 70 #define __set_fixmap_offset(idx, phys, flags) \ 71 ({ \ 72 unsigned long addr; \ 73 __set_fixmap(idx, phys, flags); \ 74 addr = fix_to_virt(idx) + ((phys) & (PAGE_SIZE - 1)); \ 75 addr; \ 76 }) 77 78 #define set_fixmap_offset(idx, phys) \ 79 __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NORMAL) 80 81 /* 82 * Some hardware wants to get fixmapped without caching. 83 */ 84 #define set_fixmap_nocache(idx, phys) \ 85 __set_fixmap(idx, phys, FIXMAP_PAGE_NOCACHE) 86 87 #define set_fixmap_offset_nocache(idx, phys) \ 88 __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NOCACHE) 89 90 /* 91 * Some fixmaps are for IO 92 */ 93 #define set_fixmap_io(idx, phys) \ 94 __set_fixmap(idx, phys, FIXMAP_PAGE_IO) 95 96 #define set_fixmap_offset_io(idx, phys) \ 97 __set_fixmap_offset(idx, phys, FIXMAP_PAGE_IO) 98 99 #endif /* __ASSEMBLY__ */ 100 #endif /* __ASM_GENERIC_FIXMAP_H */ 101