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1 | #ifndef _UST_ALIGN_H |
2 | #define _UST_ALIGN_H | |
3 | ||
4 | /* | |
4318ae1b | 5 | * lttng/align.h |
8c4127c5 MD |
6 | * |
7 | * (C) Copyright 2010-2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
8 | * | |
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9 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
10 | * of this software and associated documentation files (the "Software"), to deal | |
11 | * in the Software without restriction, including without limitation the rights | |
12 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
13 | * copies of the Software, and to permit persons to whom the Software is | |
14 | * furnished to do so, subject to the following conditions: | |
a60d70e6 | 15 | * |
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16 | * The above copyright notice and this permission notice shall be included in |
17 | * all copies or substantial portions of the Software. | |
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18 | * |
19 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
20 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
21 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
22 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
23 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
24 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
25 | * SOFTWARE. | |
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26 | */ |
27 | ||
4318ae1b | 28 | #include <lttng/bug.h> |
993e8a49 | 29 | #include <unistd.h> |
8e3484cf | 30 | #include <limits.h> |
8c4127c5 | 31 | |
8e3484cf | 32 | #ifndef PAGE_SIZE /* Cygwin limits.h defines its own PAGE_SIZE */ |
993e8a49 | 33 | #define PAGE_SIZE sysconf(_SC_PAGE_SIZE) |
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34 | #endif |
35 | ||
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36 | #define PAGE_MASK (~(PAGE_SIZE - 1)) |
37 | #define __ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask)) | |
6423c313 | 38 | #define ALIGN(v, align) __ALIGN_MASK(v, (__typeof__(v)) (align) - 1) |
993e8a49 | 39 | #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE) |
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40 | |
41 | /** | |
42 | * offset_align - Calculate the offset needed to align an object on its natural | |
43 | * alignment towards higher addresses. | |
44 | * @align_drift: object offset from an "alignment"-aligned address. | |
45 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
46 | * | |
47 | * Returns the offset that must be added to align towards higher | |
48 | * addresses. | |
49 | */ | |
50 | #define offset_align(align_drift, alignment) \ | |
51 | ({ \ | |
3f12fcef | 52 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ |
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53 | || ((alignment) & ((alignment) - 1))); \ |
54 | (((alignment) - (align_drift)) & ((alignment) - 1)); \ | |
55 | }) | |
56 | ||
57 | /** | |
58 | * offset_align_floor - Calculate the offset needed to align an object | |
59 | * on its natural alignment towards lower addresses. | |
60 | * @align_drift: object offset from an "alignment"-aligned address. | |
61 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
62 | * | |
63 | * Returns the offset that must be substracted to align towards lower addresses. | |
64 | */ | |
65 | #define offset_align_floor(align_drift, alignment) \ | |
66 | ({ \ | |
3f12fcef | 67 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ |
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68 | || ((alignment) & ((alignment) - 1))); \ |
69 | (((align_drift) - (alignment)) & ((alignment) - 1); \ | |
70 | }) | |
71 | ||
72 | #endif /* _UST_ALIGN_H */ |