projects / lttng-tools.git / blame
| Commit | Line | Data |
|---|---|---|
| 953192ba | 1 | /* |
| ab5be9fa | 2 | * Copyright (C) 2010-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 953192ba | 3 | * |
| ab5be9fa | 4 | * SPDX-License-Identifier: MIT |
| 953192ba | 5 | * |
| 953192ba MD |
6 | */ |
| 7 | ||
| ab5be9fa MJ |
8 | #ifndef _LTTNG_ALIGN_H |
| 9 | #define _LTTNG_ALIGN_H | |
| 10 | ||
| 8564ccbd | 11 | #include "bug.h" |
| 953192ba MD |
12 | #include <unistd.h> |
| 13 | #include <limits.h> | |
| 14 | ||
| d575a7f8 | 15 | #ifndef PAGE_SIZE /* Cygwin limits.h defines its own PAGE_SIZE. */ |
| 953192ba MD |
16 | #define PAGE_SIZE sysconf(_SC_PAGE_SIZE) |
| 17 | #endif | |
| 18 | ||
| d575a7f8 | 19 | #ifndef PAGE_MASK /* macOS defines its own PAGE_MASK. */ |
| 953192ba | 20 | #define PAGE_MASK (~(PAGE_SIZE - 1)) |
| d575a7f8 FD |
21 | #endif |
| 22 | ||
| 953192ba | 23 | #define __ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask)) |
| d575a7f8 FD |
24 | |
| 25 | #ifndef ALIGN /* macOS defines its own ALIGN. */ | |
| 953192ba | 26 | #define ALIGN(v, align) __ALIGN_MASK(v, (__typeof__(v)) (align) - 1) |
| d575a7f8 FD |
27 | #endif |
| 28 | ||
| d4ad24a3 MD |
29 | #define __ALIGN_FLOOR_MASK(v, mask) ((v) & ~(mask)) |
| 30 | ||
| 31 | #ifndef ALIGN_FLOOR | |
| 32 | #define ALIGN_FLOOR(v, align) __ALIGN_FLOOR_MASK(v, (__typeof__(v)) (align) - 1) | |
| 33 | #endif | |
| 34 | ||
| 953192ba MD |
35 | #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE) |
| 36 | ||
| 37 | /** | |
| 38 | * offset_align - Calculate the offset needed to align an object on its natural | |
| 39 | * alignment towards higher addresses. | |
| 40 | * @align_drift: object offset from an "alignment"-aligned address. | |
| 41 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
| 42 | * | |
| 43 | * Returns the offset that must be added to align towards higher | |
| 44 | * addresses. | |
| 45 | */ | |
| 46 | #define offset_align(align_drift, alignment) \ | |
| 47 | ({ \ | |
| 48 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ | |
| 49 | || ((alignment) & ((alignment) - 1))); \ | |
| 50 | (((alignment) - (align_drift)) & ((alignment) - 1)); \ | |
| 51 | }) | |
| 52 | ||
| 53 | /** | |
| 54 | * offset_align_floor - Calculate the offset needed to align an object | |
| 55 | * on its natural alignment towards lower addresses. | |
| 56 | * @align_drift: object offset from an "alignment"-aligned address. | |
| 57 | * @alignment: natural object alignment. Must be non-zero, power of 2. | |
| 58 | * | |
| 59 | * Returns the offset that must be substracted to align towards lower addresses. | |
| 60 | */ | |
| 61 | #define offset_align_floor(align_drift, alignment) \ | |
| 62 | ({ \ | |
| 63 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ | |
| 64 | || ((alignment) & ((alignment) - 1))); \ | |
| d07ceecd | 65 | (((align_drift) - (alignment)) & ((alignment) - 1)); \ |
| 953192ba MD |
66 | }) |
| 67 | ||
| 68 | #endif /* _LTTNG_ALIGN_H */ |