| /* 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 |
| |