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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
| commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
| tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /tools/virtio/asm/barrier.h | |
| parent | Initial commit. (diff) | |
| download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip | |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/virtio/asm/barrier.h')
| -rw-r--r-- | tools/virtio/asm/barrier.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/tools/virtio/asm/barrier.h b/tools/virtio/asm/barrier.h new file mode 100644 index 000000000..d0351f83a --- /dev/null +++ b/tools/virtio/asm/barrier.h @@ -0,0 +1,21 @@ +/* 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 + |