| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright (C) 2010-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | */ |
| 6 | |
| 7 | #ifndef _LTTNG_UST_ALIGN_H |
| 8 | #define _LTTNG_UST_ALIGN_H |
| 9 | |
| 10 | #include <lttng/ust-bug.h> |
| 11 | |
| 12 | /** |
| 13 | * lttng_ust_offset_align - Calculate the offset needed to align an object on |
| 14 | * its natural alignment towards higher addresses. |
| 15 | * @align_drift: object offset from an "alignment"-aligned address. |
| 16 | * @alignment: natural object alignment. Must be non-zero, power of 2. |
| 17 | * |
| 18 | * Returns the offset that must be added to align towards higher |
| 19 | * addresses. |
| 20 | */ |
| 21 | #define lttng_ust_offset_align(align_drift, alignment) \ |
| 22 | ({ \ |
| 23 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ |
| 24 | || ((alignment) & ((alignment) - 1))); \ |
| 25 | (((alignment) - (align_drift)) & ((alignment) - 1)); \ |
| 26 | }) |
| 27 | |
| 28 | /** |
| 29 | * lttng_ust_offset_align_floor - Calculate the offset needed to align an |
| 30 | * object on its natural alignment towards lower addresses. |
| 31 | * @align_drift: object offset from an "alignment"-aligned address. |
| 32 | * @alignment: natural object alignment. Must be non-zero, power of 2. |
| 33 | * |
| 34 | * Returns the offset that must be substracted to align towards lower addresses. |
| 35 | */ |
| 36 | #define lttng_ust_offset_align_floor(align_drift, alignment) \ |
| 37 | ({ \ |
| 38 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ |
| 39 | || ((alignment) & ((alignment) - 1))); \ |
| 40 | (((align_drift) - (alignment)) & ((alignment) - 1)); \ |
| 41 | }) |
| 42 | |
| 43 | #endif /* _LTTNG_UST_ALIGN_H */ |