#ifndef _UST_ALIGN_H #define _UST_ALIGN_H /* * lttng/align.h * * (C) Copyright 2010-2011 - Mathieu Desnoyers * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include #include #include #ifndef PAGE_SIZE /* Cygwin limits.h defines its own PAGE_SIZE */ #define PAGE_SIZE sysconf(_SC_PAGE_SIZE) #endif #define PAGE_MASK (~(PAGE_SIZE - 1)) #define __ALIGN_MASK(v, mask) (((v) + (mask)) & ~(mask)) #define ALIGN(v, align) __ALIGN_MASK(v, (__typeof__(v)) (align) - 1) #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE) /** * offset_align - Calculate the offset needed to align an object on its natural * alignment towards higher addresses. * @align_drift: object offset from an "alignment"-aligned address. * @alignment: natural object alignment. Must be non-zero, power of 2. * * Returns the offset that must be added to align towards higher * addresses. */ #define offset_align(align_drift, alignment) \ ({ \ LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ || ((alignment) & ((alignment) - 1))); \ (((alignment) - (align_drift)) & ((alignment) - 1)); \ }) /** * offset_align_floor - Calculate the offset needed to align an object * on its natural alignment towards lower addresses. * @align_drift: object offset from an "alignment"-aligned address. * @alignment: natural object alignment. Must be non-zero, power of 2. * * Returns the offset that must be substracted to align towards lower addresses. */ #define offset_align_floor(align_drift, alignment) \ ({ \ LTTNG_BUILD_RUNTIME_BUG_ON((alignment) == 0 \ || ((alignment) & ((alignment) - 1))); \ (((align_drift) - (alignment)) & ((alignment) - 1)); \ }) #endif /* _UST_ALIGN_H */