diff options
Diffstat (limited to 'src/include/gpxe/virtio-ring.h')
-rw-r--r-- | src/include/gpxe/virtio-ring.h | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/src/include/gpxe/virtio-ring.h b/src/include/gpxe/virtio-ring.h new file mode 100644 index 00000000..33060b11 --- /dev/null +++ b/src/include/gpxe/virtio-ring.h @@ -0,0 +1,93 @@ +#ifndef _VIRTIO_RING_H_ +# define _VIRTIO_RING_H_ +#define PAGE_SHIFT (12) +#define PAGE_SIZE (1<<PAGE_SHIFT) +#define PAGE_MASK (PAGE_SIZE-1) + +/* Status byte for guest to report progress, and synchronize features. */ +/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */ +#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1 +/* We have found a driver for the device. */ +#define VIRTIO_CONFIG_S_DRIVER 2 +/* Driver has used its parts of the config, and is happy */ +#define VIRTIO_CONFIG_S_DRIVER_OK 4 +/* We've given up on this device. */ +#define VIRTIO_CONFIG_S_FAILED 0x80 + +#define MAX_QUEUE_NUM (512) + +#define VRING_DESC_F_NEXT 1 +#define VRING_DESC_F_WRITE 2 + +#define VRING_AVAIL_F_NO_INTERRUPT 1 + +#define VRING_USED_F_NO_NOTIFY 1 + +struct vring_desc +{ + u64 addr; + u32 len; + u16 flags; + u16 next; +}; + +struct vring_avail +{ + u16 flags; + u16 idx; + u16 ring[0]; +}; + +struct vring_used_elem +{ + u32 id; + u32 len; +}; + +struct vring_used +{ + u16 flags; + u16 idx; + struct vring_used_elem ring[]; +}; + +struct vring { + unsigned int num; + struct vring_desc *desc; + struct vring_avail *avail; + struct vring_used *used; +}; + +static inline void vring_init(struct vring *vr, + unsigned int num, unsigned char *queue) +{ + unsigned int i; + unsigned long pa; + + vr->num = num; + + /* physical address of desc must be page aligned */ + + pa = virt_to_phys(queue); + pa = (pa + PAGE_MASK) & ~PAGE_MASK; + vr->desc = phys_to_virt(pa); + + vr->avail = (struct vring_avail *)&vr->desc[num]; + + /* physical address of used must be page aligned */ + + pa = virt_to_phys(&vr->avail->ring[num]); + pa = (pa + PAGE_MASK) & ~PAGE_MASK; + vr->used = phys_to_virt(pa); + + for (i = 0; i < num - 1; i++) + vr->desc[i].next = i + 1; + vr->desc[i].next = 0; +} + +#define vring_size(num) \ + (((((sizeof(struct vring_desc) * num) + \ + (sizeof(struct vring_avail) + sizeof(u16) * num)) \ + + PAGE_MASK) & ~PAGE_MASK) + \ + (sizeof(struct vring_used) + sizeof(struct vring_used_elem) * num)) +#endif /* _VIRTIO_RING_H_ */ |