| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 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 | #if !defined(FIXMAP_PAGE_RO) && defined(PAGE_KERNEL_RO) |
| 50 | #define FIXMAP_PAGE_RO PAGE_KERNEL_RO |
| 51 | #endif |
| 52 | #ifndef FIXMAP_PAGE_NOCACHE |
| 53 | #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE |
| 54 | #endif |
| 55 | #ifndef FIXMAP_PAGE_IO |
| 56 | #define FIXMAP_PAGE_IO PAGE_KERNEL_IO |
| 57 | #endif |
| 58 | #ifndef FIXMAP_PAGE_CLEAR |
| 59 | #define FIXMAP_PAGE_CLEAR __pgprot(0) |
| 60 | #endif |
| 61 | |
| 62 | #ifndef set_fixmap |
| 63 | #define set_fixmap(idx, phys) \ |
| 64 | __set_fixmap(idx, phys, FIXMAP_PAGE_NORMAL) |
| 65 | #endif |
| 66 | |
| 67 | #ifndef clear_fixmap |
| 68 | #define clear_fixmap(idx) \ |
| 69 | __set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR) |
| 70 | #endif |
| 71 | |
| 72 | /* Return a pointer with offset calculated */ |
| 73 | #define __set_fixmap_offset(idx, phys, flags) \ |
| 74 | ({ \ |
| 75 | unsigned long ________addr; \ |
| 76 | __set_fixmap(idx, phys, flags); \ |
| 77 | ________addr = fix_to_virt(idx) + ((phys) & (PAGE_SIZE - 1)); \ |
| 78 | ________addr; \ |
| 79 | }) |
| 80 | |
| 81 | #define set_fixmap_offset(idx, phys) \ |
| 82 | __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NORMAL) |
| 83 | |
| 84 | /* |
| 85 | * Some hardware wants to get fixmapped without caching. |
| 86 | */ |
| 87 | #define set_fixmap_nocache(idx, phys) \ |
| 88 | __set_fixmap(idx, phys, FIXMAP_PAGE_NOCACHE) |
| 89 | |
| 90 | #define set_fixmap_offset_nocache(idx, phys) \ |
| 91 | __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NOCACHE) |
| 92 | |
| 93 | /* |
| 94 | * Some fixmaps are for IO |
| 95 | */ |
| 96 | #define set_fixmap_io(idx, phys) \ |
| 97 | __set_fixmap(idx, phys, FIXMAP_PAGE_IO) |
| 98 | |
| 99 | #define set_fixmap_offset_io(idx, phys) \ |
| 100 | __set_fixmap_offset(idx, phys, FIXMAP_PAGE_IO) |
| 101 | |
| 102 | #endif /* __ASSEMBLY__ */ |
| 103 | #endif /* __ASM_GENERIC_FIXMAP_H */ |