/* * Copyright (c) 2018 Richard Braun. * Copyright (c) 2017-2018 Agustina Arzille. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . * * * Type-generic memory-model-aware atomic operations. * * For portability reasons, this interface restricts atomic operation * sizes to 32-bit and 64-bit. * * Some configurations may not support 64-bit operations. Check if the * ATOMIC_HAVE_64B_OPS macro is defined to find out. * * TODO Replace mentions of "memory barriers" throughout the code with * C11 memory model terminology. */ #ifndef KERN_ATOMIC_H #define KERN_ATOMIC_H #if !defined(CONFIG_SMP) && defined(CONFIG_LATOMIC_REPLACE_ATOMIC_ON_UP) #define ATOMIC_USE_LATOMIC #endif #ifdef ATOMIC_USE_LATOMIC #include /* * Local atomic operations always provide 64-bit support, by using the * generic versions which disable interrupts as a last resort. */ #define ATOMIC_HAVE_64B_OPS /* * Memory orders. * * XXX Consume ordering is currently aliased to acquire. */ #define ATOMIC_RELAXED LATOMIC_RELAXED #define ATOMIC_CONSUME LATOMIC_ACQUIRE #define ATOMIC_ACQUIRE LATOMIC_ACQUIRE #define ATOMIC_RELEASE LATOMIC_RELEASE #define ATOMIC_ACQ_REL LATOMIC_ACQ_REL #define ATOMIC_SEQ_CST LATOMIC_SEQ_CST #define atomic_load latomic_load #define atomic_store latomic_store #define atomic_swap latomic_swap #define atomic_cas latomic_cas #define atomic_fetch_add latomic_fetch_add #define atomic_fetch_sub latomic_fetch_sub #define atomic_fetch_and latomic_fetch_and #define atomic_fetch_or latomic_fetch_or #define atomic_fetch_xor latomic_fetch_xor #define atomic_add latomic_add #define atomic_sub latomic_sub #define atomic_and latomic_and #define atomic_or latomic_or #define atomic_xor latomic_xor #define atomic_fence latomic_fence #else /* ATOMIC_USE_LATOMIC */ #include #include #include /* * Supported memory orders. */ #define ATOMIC_RELAXED __ATOMIC_RELAXED #define ATOMIC_CONSUME __ATOMIC_CONSUME #define ATOMIC_ACQUIRE __ATOMIC_ACQUIRE #define ATOMIC_RELEASE __ATOMIC_RELEASE #define ATOMIC_ACQ_REL __ATOMIC_ACQ_REL #define ATOMIC_SEQ_CST __ATOMIC_SEQ_CST #include #define atomic_load(ptr, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ ((typeof(*(ptr)))atomic_select(ptr, load)(ptr, memorder)); \ MACRO_END #define atomic_store(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ atomic_select(ptr, store)(ptr, val, memorder); \ MACRO_END /* * For compare-and-swap, deviate a little from the standard, and only * return the value before the comparison, leaving it up to the user to * determine whether the swap was actually performed or not. * * Also, note that the memory order in case of failure is relaxed. This is * because atomic CAS is typically used in a loop. However, if a different * code path is taken on failure (rather than retrying), then the user * should be aware that a memory fence might be necessary. */ #define atomic_cas(ptr, oval, nval, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ ((typeof(*(ptr)))atomic_select(ptr, cas)(ptr, oval, nval, memorder)); \ MACRO_END #define atomic_swap(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ ((typeof(*(ptr)))atomic_select(ptr, swap)(ptr, val, memorder)); \ MACRO_END #define atomic_fetch_add(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ ((typeof(*(ptr)))atomic_select(ptr, fetch_add)(ptr, val, memorder)); \ MACRO_END #define atomic_fetch_sub(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ ((typeof(*(ptr)))atomic_select(ptr, fetch_sub)(ptr, val, memorder)); \ MACRO_END #define atomic_fetch_and(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ ((typeof(*(ptr)))atomic_select(ptr, fetch_and)(ptr, val, memorder)); \ MACRO_END #define atomic_fetch_or(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ ((typeof(*(ptr)))atomic_select(ptr, fetch_or)(ptr, val, memorder)); \ MACRO_END #define atomic_fetch_xor(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ ((typeof(*(ptr)))atomic_select(ptr, fetch_xor)(ptr, val, memorder)); \ MACRO_END #define atomic_add(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ atomic_select(ptr, add)(ptr, val, memorder); \ MACRO_END #define atomic_sub(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ atomic_select(ptr, sub)(ptr, val, memorder); \ MACRO_END #define atomic_and(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ atomic_select(ptr, and)(ptr, val, memorder); \ MACRO_END #define atomic_or(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ atomic_select(ptr, or)(ptr, val, memorder); \ MACRO_END #define atomic_xor(ptr, val, memorder) \ MACRO_BEGIN \ assert(atomic_ptr_aligned(ptr)); \ atomic_select(ptr, xor)(ptr, val, memorder); \ MACRO_END #define atomic_fence(memorder) __atomic_thread_fence(memorder) #endif /* ATOMIC_USE_LATOMIC */ #endif /* KERN_ATOMIC_H */