| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright (C) 2010-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | */ |
| 6 | |
| 7 | #ifndef _UST_ALIGN_H |
| 8 | #define _UST_ALIGN_H |
| 9 | |
| 10 | #include <lttng/bug.h> |
| 11 | #include <unistd.h> |
| 12 | #include <limits.h> |
| 13 | |
| 14 | #ifdef __FreeBSD__ |
| 15 | #include <machine/param.h> |
| 16 | #endif |
| 17 | |
| 18 | #ifdef _SC_PAGE_SIZE |
| 19 | #define LTTNG_UST_PAGE_SIZE sysconf(_SC_PAGE_SIZE) |
| 20 | #elif defined(PAGE_SIZE) |
| 21 | #define LTTNG_UST_PAGE_SIZE PAGE_SIZE |
| 22 | #else |
| 23 | #error "Please add page size detection for your OS." |
| 24 | #endif |
| 25 | |
| 26 | #define LTTNG_UST_PAGE_MASK (~(LTTNG_UST_PAGE_SIZE - 1)) |
| 27 | |
| 28 | #define __LTTNG_UST_ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask)) |
| 29 | #define LTTNG_UST_ALIGN(v, align) __LTTNG_UST_ALIGN_MASK(v, (__typeof__(v)) (align) - 1) |
| 30 | #define LTTNG_UST_PAGE_ALIGN(addr) LTTNG_UST_ALIGN(addr, LTTNG_UST_PAGE_SIZE) |
| 31 | |
| 32 | /** |
| 33 | * lttng_ust_offset_align - Calculate the offset needed to align an object on |
| 34 | * its natural alignment towards higher addresses. |
| 35 | * @align_drift: object offset from an "alignment"-aligned address. |
| 36 | * @alignment: natural object alignment. Must be non-zero, power of 2. |
| 37 | * |
| 38 | * Returns the offset that must be added to align towards higher |
| 39 | * addresses. |
| 40 | */ |
| 41 | #define lttng_ust_offset_align(align_drift, alignment) \ |
| 42 | ({ \ |
| 43 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ |
| 44 | || ((alignment) & ((alignment) - 1))); \ |
| 45 | (((alignment) - (align_drift)) & ((alignment) - 1)); \ |
| 46 | }) |
| 47 | |
| 48 | /** |
| 49 | * lttng_ust_offset_align_floor - Calculate the offset needed to align an |
| 50 | * object on its natural alignment towards lower addresses. |
| 51 | * @align_drift: object offset from an "alignment"-aligned address. |
| 52 | * @alignment: natural object alignment. Must be non-zero, power of 2. |
| 53 | * |
| 54 | * Returns the offset that must be substracted to align towards lower addresses. |
| 55 | */ |
| 56 | #define lttng_ust_offset_align_floor(align_drift, alignment) \ |
| 57 | ({ \ |
| 58 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ |
| 59 | || ((alignment) & ((alignment) - 1))); \ |
| 60 | (((align_drift) - (alignment)) & ((alignment) - 1)); \ |
| 61 | }) |
| 62 | |
| 63 | /* |
| 64 | * Non-namespaced defines for backwards compatibility, |
| 65 | * introduced in 2.13, should be removed in the future. |
| 66 | */ |
| 67 | |
| 68 | /* Cygwin limits.h defines its own PAGE_SIZE */ |
| 69 | #ifndef PAGE_SIZE |
| 70 | #define PAGE_SIZE LTTNG_UST_PAGE_SIZE |
| 71 | #endif |
| 72 | |
| 73 | /* FreeBSD and macOS defines their own PAGE_MASK. */ |
| 74 | #ifndef PAGE_MASK |
| 75 | #define PAGE_MASK LTTNG_UST_PAGE_MASK |
| 76 | #endif |
| 77 | |
| 78 | /* FreeBSD machine/param.h defines its own ALIGN */ |
| 79 | #ifndef ALIGN |
| 80 | #define ALIGN LTTNG_UST_ALIGN |
| 81 | #endif |
| 82 | |
| 83 | #ifndef PAGE_ALIGN |
| 84 | #define PAGE_ALIGN LTTNG_UST_PAGE_ALIGN |
| 85 | #endif |
| 86 | |
| 87 | #ifndef offset_align |
| 88 | #define offset_align lttng_ust_offset_align |
| 89 | #endif |
| 90 | |
| 91 | #ifndef offset_align_floor |
| 92 | #define offset_align_floor lttng_ust_offset_align_floor |
| 93 | #endif |
| 94 | |
| 95 | #endif /* _UST_ALIGN_H */ |