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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - include/linux/virtio_ring.h
1 #ifndef _LINUX_VIRTIO_RING_H
2 #define _LINUX_VIRTIO_RING_H
4 #include <asm/barrier.h>
5 #include <linux/irqreturn.h>
6 #include <uapi/linux/virtio_ring.h>
9 * Barriers in virtio are tricky. Non-SMP virtio guests can't assume
10 * they're not on an SMP host system, so they need to assume real
11 * barriers. Non-SMP virtio hosts could skip the barriers, but does
14 * For virtio_pci on SMP, we don't need to order with respect to MMIO
15 * accesses through relaxed memory I/O windows, so smp_mb() et al are
18 * For using virtio to talk to real devices (eg. other heterogeneous
19 * CPUs) we do need real barriers. In theory, we could be using both
20 * kinds of virtio, so it's a runtime decision, and the branch is
21 * actually quite cheap.
25 static inline void virtio_mb(bool weak_barriers
)
33 static inline void virtio_rmb(bool weak_barriers
)
41 static inline void virtio_wmb(bool weak_barriers
)
49 static inline void virtio_mb(bool weak_barriers
)
54 static inline void virtio_rmb(bool weak_barriers
)
59 static inline void virtio_wmb(bool weak_barriers
)
68 struct virtqueue
*vring_new_virtqueue(unsigned int index
,
70 unsigned int vring_align
,
71 struct virtio_device
*vdev
,
74 void (*notify
)(struct virtqueue
*vq
),
75 void (*callback
)(struct virtqueue
*vq
),
77 void vring_del_virtqueue(struct virtqueue
*vq
);
78 /* Filter out transport-specific feature bits. */
79 void vring_transport_features(struct virtio_device
*vdev
);
81 irqreturn_t
vring_interrupt(int irq
, void *_vq
);
82 #endif /* _LINUX_VIRTIO_RING_H */