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| author | Michael S. Tsirkin <mst@redhat.com> | 2018-01-26 02:36:42 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-01-29 20:02:55 +0300 |
| commit | b4eab7de6685ee2691a7e297d511a126dbf53207 (patch) | |
| tree | 1166be9a6383433ee2f030bb3f85f8be41c54b13 /tools | |
| parent | 6dd42157830d875bdd3c6fefd05cbcf0875b51e8 (diff) | |
| download | linux-b4eab7de6685ee2691a7e297d511a126dbf53207.tar.xz | |
tools/virtio: copy READ/WRITE_ONCE
This is to make ptr_ring test build again.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/virtio/ringtest/main.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/tools/virtio/ringtest/main.h b/tools/virtio/ringtest/main.h index 5706e075adf2..593a3289c87d 100644 --- a/tools/virtio/ringtest/main.h +++ b/tools/virtio/ringtest/main.h @@ -134,4 +134,61 @@ static inline void busy_wait(void) barrier(); \ } while (0) +#if defined(__i386__) || defined(__x86_64__) || defined(__s390x__) +#define smp_wmb() barrier() +#else +#define smp_wmb() smp_release() +#endif + +#ifdef __alpha__ +#define smp_read_barrier_depends() smp_acquire() +#else +#define smp_read_barrier_depends() do {} while(0) +#endif + +static __always_inline +void __read_once_size(const volatile void *p, void *res, int size) +{ + switch (size) { \ + case 1: *(unsigned char *)res = *(volatile unsigned char *)p; break; \ + case 2: *(unsigned short *)res = *(volatile unsigned short *)p; break; \ + case 4: *(unsigned int *)res = *(volatile unsigned int *)p; break; \ + case 8: *(unsigned long long *)res = *(volatile unsigned long long *)p; break; \ + default: \ + barrier(); \ + __builtin_memcpy((void *)res, (const void *)p, size); \ + barrier(); \ + } \ +} + +static __always_inline void __write_once_size(volatile void *p, void *res, int size) +{ + switch (size) { + case 1: *(volatile unsigned char *)p = *(unsigned char *)res; break; + case 2: *(volatile unsigned short *)p = *(unsigned short *)res; break; + case 4: *(volatile unsigned int *)p = *(unsigned int *)res; break; + case 8: *(volatile unsigned long long *)p = *(unsigned long long *)res; break; + default: + barrier(); + __builtin_memcpy((void *)p, (const void *)res, size); + barrier(); + } +} + +#define READ_ONCE(x) \ +({ \ + union { typeof(x) __val; char __c[1]; } __u; \ + __read_once_size(&(x), __u.__c, sizeof(x)); \ + smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \ + __u.__val; \ +}) + +#define WRITE_ONCE(x, val) \ +({ \ + union { typeof(x) __val; char __c[1]; } __u = \ + { .__val = (typeof(x)) (val) }; \ + __write_once_size(&(x), __u.__c, sizeof(x)); \ + __u.__val; \ +}) + #endif |