/* SPDX-License-Identifier: GPL-2.0 */ #if defined(__i386__) || defined(__x86_64__) #define barrier() asm volatile("" ::: "memory") #define virt_mb() __sync_synchronize() #define virt_rmb() barrier() #define virt_wmb() barrier() /* Atomic store should be enough, but gcc generates worse code in that case. */ #define virt_store_mb(var, value) do { \ typeof(var) virt_store_mb_value = (value); \ __atomic_exchange(&(var), &virt_store_mb_value, &virt_store_mb_value, \ __ATOMIC_SEQ_CST); \ barrier(); \ } while (0); /* Weak barriers should be used. If not - it's a bug */ # define mb() abort() # define dma_rmb() abort() # define dma_wmb() abort() #else #error Please fill in barrier macros #endif