| 1 | #ifndef _UST_ALIGN_H |
| 2 | #define _UST_ALIGN_H |
| 3 | |
| 4 | /* |
| 5 | * lttng/align.h |
| 6 | * |
| 7 | * (C) Copyright 2010-2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 8 | * |
| 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: |
| 15 | * |
| 16 | * The above copyright notice and this permission notice shall be included in |
| 17 | * all copies or substantial portions of the Software. |
| 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. |
| 26 | */ |
| 27 | |
| 28 | #include <lttng/bug.h> |
| 29 | #include <unistd.h> |
| 30 | #include <limits.h> |
| 31 | |
| 32 | #ifdef __FreeBSD__ |
| 33 | #include <machine/param.h> |
| 34 | #endif |
| 35 | |
| 36 | #ifdef _SC_PAGE_SIZE |
| 37 | #define LTTNG_UST_PAGE_SIZE sysconf(_SC_PAGE_SIZE) |
| 38 | #elif defined(PAGE_SIZE) |
| 39 | #define LTTNG_UST_PAGE_SIZE PAGE_SIZE |
| 40 | #else |
| 41 | #error "Please add page size detection for your OS." |
| 42 | #endif |
| 43 | |
| 44 | #define LTTNG_UST_PAGE_MASK (~(LTTNG_UST_PAGE_SIZE - 1)) |
| 45 | |
| 46 | #define __LTTNG_UST_ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask)) |
| 47 | #define LTTNG_UST_ALIGN(v, align) __LTTNG_UST_ALIGN_MASK(v, (__typeof__(v)) (align) - 1) |
| 48 | #define LTTNG_UST_PAGE_ALIGN(addr) LTTNG_UST_ALIGN(addr, LTTNG_UST_PAGE_SIZE) |
| 49 | |
| 50 | /** |
| 51 | * lttng_ust_offset_align - Calculate the offset needed to align an object on |
| 52 | * its natural alignment towards higher addresses. |
| 53 | * @align_drift: object offset from an "alignment"-aligned address. |
| 54 | * @alignment: natural object alignment. Must be non-zero, power of 2. |
| 55 | * |
| 56 | * Returns the offset that must be added to align towards higher |
| 57 | * addresses. |
| 58 | */ |
| 59 | #define lttng_ust_offset_align(align_drift, alignment) \ |
| 60 | ({ \ |
| 61 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ |
| 62 | || ((alignment) & ((alignment) - 1))); \ |
| 63 | (((alignment) - (align_drift)) & ((alignment) - 1)); \ |
| 64 | }) |
| 65 | |
| 66 | /** |
| 67 | * lttng_ust_offset_align_floor - Calculate the offset needed to align an |
| 68 | * object on its natural alignment towards lower addresses. |
| 69 | * @align_drift: object offset from an "alignment"-aligned address. |
| 70 | * @alignment: natural object alignment. Must be non-zero, power of 2. |
| 71 | * |
| 72 | * Returns the offset that must be substracted to align towards lower addresses. |
| 73 | */ |
| 74 | #define lttng_ust_offset_align_floor(align_drift, alignment) \ |
| 75 | ({ \ |
| 76 | LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ |
| 77 | || ((alignment) & ((alignment) - 1))); \ |
| 78 | (((align_drift) - (alignment)) & ((alignment) - 1)); \ |
| 79 | }) |
| 80 | |
| 81 | /* |
| 82 | * Non-namespaced defines for backwards compatibility, |
| 83 | * introduced in 2.13, should be removed in the future. |
| 84 | */ |
| 85 | |
| 86 | /* Cygwin limits.h defines its own PAGE_SIZE */ |
| 87 | #ifndef PAGE_SIZE |
| 88 | #define PAGE_SIZE LTTNG_UST_PAGE_SIZE |
| 89 | #endif |
| 90 | |
| 91 | /* FreeBSD and macOS defines their own PAGE_MASK. */ |
| 92 | #ifndef PAGE_MASK |
| 93 | #define PAGE_MASK LTTNG_UST_PAGE_MASK |
| 94 | #endif |
| 95 | |
| 96 | /* FreeBSD machine/param.h defines its own ALIGN */ |
| 97 | #ifndef ALIGN |
| 98 | #define ALIGN LTTNG_UST_ALIGN |
| 99 | #endif |
| 100 | |
| 101 | #ifndef PAGE_ALIGN |
| 102 | #define PAGE_ALIGN LTTNG_UST_PAGE_ALIGN |
| 103 | #endif |
| 104 | |
| 105 | #ifndef offset_align |
| 106 | #define offset_align lttng_ust_offset_align |
| 107 | #endif |
| 108 | |
| 109 | #ifndef offset_align_floor |
| 110 | #define offset_align_floor lttng_ust_offset_align_floor |
| 111 | #endif |
| 112 | |
| 113 | #endif /* _UST_ALIGN_H */ |