| 1 | |
| 2 | * fixmap.h: compile-time virtual memory allocation
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| 3 | *
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| 4 | * This file is subject to the terms and conditions of the GNU General Public
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| 5 | * License. See the file "COPYING" in the main directory of this archive
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| 6 | * for more details.
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| 7 | *
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| 8 | * Copyright (C) 1998 Ingo Molnar
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| 9 | *
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| 10 | * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
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| 11 | * x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009
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| 12 | * Break out common bits to asm-generic by Mark Salter, November 2013
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| 13 |
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| 14 |
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| 15 | #ifndef __ASM_GENERIC_FIXMAP_H
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| 16 | #define __ASM_GENERIC_FIXMAP_H
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| 17 |
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| 18 | #include <linux/bug.h>
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| 19 |
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| 20 | #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
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| 21 | #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
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| 22 |
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| 23 | #ifndef __ASSEMBLY__
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| 24 | |
| 25 | * 'index to address' translation. If anyone tries to use the idx
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| 26 | * directly without translation, we catch the bug with a NULL-deference
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| 27 | * kernel oops. Illegal ranges of incoming indices are caught too.
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| 28 |
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| 29 | static __always_inline unsigned long fix_to_virt(const unsigned int idx)
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| 30 | {
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| 31 | BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
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| 32 | return __fix_to_virt(idx);
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| 33 | }
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| 34 |
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| 35 | static inline unsigned long virt_to_fix(const unsigned long vaddr)
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| 36 | {
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| 37 | BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
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| 38 | return __virt_to_fix(vaddr);
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| 39 | }
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| 40 |
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| 41 | |
| 42 | * Provide some reasonable defaults for page flags.
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| 43 | * Not all architectures use all of these different types and some
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| 44 | * architectures use different names.
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| 45 |
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| 46 | #ifndef FIXMAP_PAGE_NORMAL
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| 47 | #define FIXMAP_PAGE_NORMAL PAGE_KERNEL
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| 48 | #endif
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| 49 | #if !defined(FIXMAP_PAGE_RO) && defined(PAGE_KERNEL_RO)
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| 50 | #define FIXMAP_PAGE_RO PAGE_KERNEL_RO
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| 51 | #endif
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| 52 | #ifndef FIXMAP_PAGE_NOCACHE
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| 53 | #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE
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| 54 | #endif
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| 55 | #ifndef FIXMAP_PAGE_IO
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| 56 | #define FIXMAP_PAGE_IO PAGE_KERNEL_IO
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| 57 | #endif
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| 58 | #ifndef FIXMAP_PAGE_CLEAR
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| 59 | #define FIXMAP_PAGE_CLEAR __pgprot(0)
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| 60 | #endif
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| 61 |
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| 62 | #ifndef set_fixmap
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| 63 | #define set_fixmap(idx, phys) \
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| 64 | __set_fixmap(idx, phys, FIXMAP_PAGE_NORMAL)
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| 65 | #endif
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| 66 |
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| 67 | #ifndef clear_fixmap
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| 68 | #define clear_fixmap(idx) \
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| 69 | __set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR)
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| 70 | #endif
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| 71 |
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| 72 |
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| 73 | #define __set_fixmap_offset(idx, phys, flags) \
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| 74 | ({ \
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| 75 | unsigned long addr; \
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| 76 | __set_fixmap(idx, phys, flags); \
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| 77 | addr = fix_to_virt(idx) + ((phys) & (PAGE_SIZE - 1)); \
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| 78 | addr; \
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| 79 | })
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| 80 |
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| 81 | #define set_fixmap_offset(idx, phys) \
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| 82 | __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NORMAL)
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| 83 |
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| 84 | |
| 85 | * Some hardware wants to get fixmapped without caching.
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| 86 |
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| 87 | #define set_fixmap_nocache(idx, phys) \
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| 88 | __set_fixmap(idx, phys, FIXMAP_PAGE_NOCACHE)
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| 89 |
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| 90 | #define set_fixmap_offset_nocache(idx, phys) \
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| 91 | __set_fixmap_offset(idx, phys, FIXMAP_PAGE_NOCACHE)
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| 92 |
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| 93 | |
| 94 | * Some fixmaps are for IO
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| 95 |
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| 96 | #define set_fixmap_io(idx, phys) \
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| 97 | __set_fixmap(idx, phys, FIXMAP_PAGE_IO)
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| 98 |
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| 99 | #define set_fixmap_offset_io(idx, phys) \
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| 100 | __set_fixmap_offset(idx, phys, FIXMAP_PAGE_IO)
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| 101 |
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| 102 | #endif
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| 103 | #endif
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