You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
67 lines
1.7 KiB
67 lines
1.7 KiB
#ifndef _LINUX_VIRTIO_RING_H |
|
#define _LINUX_VIRTIO_RING_H |
|
|
|
#include <asm/barrier.h> |
|
#include <linux/irqreturn.h> |
|
#include <uapi/linux/virtio_ring.h> |
|
|
|
/* |
|
* Barriers in virtio are tricky. Non-SMP virtio guests can't assume |
|
* they're not on an SMP host system, so they need to assume real |
|
* barriers. Non-SMP virtio hosts could skip the barriers, but does |
|
* anyone care? |
|
* |
|
* For virtio_pci on SMP, we don't need to order with respect to MMIO |
|
* accesses through relaxed memory I/O windows, so smp_mb() et al are |
|
* sufficient. |
|
* |
|
* For using virtio to talk to real devices (eg. other heterogeneous |
|
* CPUs) we do need real barriers. In theory, we could be using both |
|
* kinds of virtio, so it's a runtime decision, and the branch is |
|
* actually quite cheap. |
|
*/ |
|
|
|
static inline void virtio_mb(bool weak_barriers) |
|
{ |
|
#ifdef CONFIG_SMP |
|
if (weak_barriers) |
|
smp_mb(); |
|
else |
|
#endif |
|
mb(); |
|
} |
|
|
|
static inline void virtio_rmb(bool weak_barriers) |
|
{ |
|
if (weak_barriers) |
|
dma_rmb(); |
|
else |
|
rmb(); |
|
} |
|
|
|
static inline void virtio_wmb(bool weak_barriers) |
|
{ |
|
if (weak_barriers) |
|
dma_wmb(); |
|
else |
|
wmb(); |
|
} |
|
|
|
struct virtio_device; |
|
struct virtqueue; |
|
|
|
struct virtqueue *vring_new_virtqueue(unsigned int index, |
|
unsigned int num, |
|
unsigned int vring_align, |
|
struct virtio_device *vdev, |
|
bool weak_barriers, |
|
void *pages, |
|
bool (*notify)(struct virtqueue *vq), |
|
void (*callback)(struct virtqueue *vq), |
|
const char *name); |
|
void vring_del_virtqueue(struct virtqueue *vq); |
|
/* Filter out transport-specific feature bits. */ |
|
void vring_transport_features(struct virtio_device *vdev); |
|
|
|
irqreturn_t vring_interrupt(int irq, void *_vq); |
|
#endif /* _LINUX_VIRTIO_RING_H */
|
|
|