projects / lttng-modules.git / blame
| Commit | Line | Data |
|---|---|---|
| b7cdc182 | 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
| 9f36eaed | 2 | * |
| a071f25d | 3 | * lttng/align.h |
| 6c29ebe7 | 4 | * |
| 886d51a3 | 5 | * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 6c29ebe7 MD |
6 | */ |
| 7 | ||
| 9f36eaed MJ |
8 | #ifndef _LTTNG_ALIGN_H |
| 9 | #define _LTTNG_ALIGN_H | |
| 10 | ||
| 6c29ebe7 MD |
11 | #ifdef __KERNEL__ |
| 12 | ||
| 13 | #include <linux/types.h> | |
| a071f25d | 14 | #include <lttng/bug.h> |
| 6c29ebe7 MD |
15 | |
| 16 | #define ALIGN_FLOOR(x, a) __ALIGN_FLOOR_MASK(x, (typeof(x)) (a) - 1) | |
| 17 | #define __ALIGN_FLOOR_MASK(x, mask) ((x) & ~(mask)) | |
| 18 | #define PTR_ALIGN_FLOOR(p, a) \ | |
| 19 | ((typeof(p)) ALIGN_FLOOR((unsigned long) (p), a)) | |
| 20 | ||
| 21 | /* | |
| 22 | * Align pointer on natural object alignment. | |
| 23 | */ | |
| 24 | #define object_align(obj) PTR_ALIGN(obj, __alignof__(*(obj))) | |
| 25 | #define object_align_floor(obj) PTR_ALIGN_FLOOR(obj, __alignof__(*(obj))) | |
| 26 | ||
| 27 | /** | |
| 28 | * offset_align - Calculate the offset needed to align an object on its natural | |
| 29 | * alignment towards higher addresses. | |
| 30 | * @align_drift: object offset from an "alignment"-aligned address. | |
| 31 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
| 32 | * | |
| 33 | * Returns the offset that must be added to align towards higher | |
| 34 | * addresses. | |
| 35 | */ | |
| 36 | #define offset_align(align_drift, alignment) \ | |
| 37 | ({ \ | |
| 38 | BUILD_RUNTIME_BUG_ON((alignment) == 0 \ | |
| 39 | || ((alignment) & ((alignment) - 1))); \ | |
| 40 | (((alignment) - (align_drift)) & ((alignment) - 1)); \ | |
| 41 | }) | |
| 42 | ||
| 43 | /** | |
| 44 | * offset_align_floor - Calculate the offset needed to align an object | |
| 45 | * on its natural alignment towards lower addresses. | |
| 46 | * @align_drift: object offset from an "alignment"-aligned address. | |
| 47 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
| 48 | * | |
| 49 | * Returns the offset that must be substracted to align towards lower addresses. | |
| 50 | */ | |
| 51 | #define offset_align_floor(align_drift, alignment) \ | |
| 52 | ({ \ | |
| 53 | BUILD_RUNTIME_BUG_ON((alignment) == 0 \ | |
| 54 | || ((alignment) & ((alignment) - 1))); \ | |
| e860f019 | 55 | (((align_drift) - (alignment)) & ((alignment) - 1)); \ |
| 6c29ebe7 MD |
56 | }) |
| 57 | ||
| 58 | #endif /* __KERNEL__ */ | |
| 59 | ||
| 60 | #endif |