virtio-ring.c File Reference

#include "etherboot.h"
#include "gpxe/io.h"
#include "gpxe/virtio-ring.h"
#include "gpxe/virtio-pci.h"

Go to the source code of this file.

Defines
#define	BUG()
#define	BUG_ON(condition)   do { if (condition) BUG(); } while (0)
Functions
void	vring_detach (struct vring_virtqueue *vq, unsigned int head)
int	vring_get_buf (struct vring_virtqueue *vq, unsigned int *len)
void	vring_add_buf (struct vring_virtqueue *vq, struct vring_list list[], unsigned int out, unsigned int in, int index, int num_added)
void	vring_kick (unsigned int ioaddr, struct vring_virtqueue *vq, int num_added)

---

Define Documentation

 

#define BUG

(

)

Value:

do { \
   printf("BUG: failure at %s:%d/%s()!\n", \
          __FILE__, __LINE__, __FUNCTION__); \
   while(1); \
} while (0)

Definition at line 22 of file virtio-ring.c.

#define BUG_ON

(

condition

)

do { if (condition) BUG(); } while (0)

Definition at line 27 of file virtio-ring.c.

Referenced by virtnet_poll(), virtnet_transmit(), vring_add_buf(), and vring_get_buf().

---

Function Documentation

void vring_detach	(	struct vring_virtqueue *	vq,
		unsigned int	head
	)

Definition at line 35 of file virtio-ring.c.

References vring::desc, vring_desc::flags, vring_virtqueue::free_head, vring_desc::next, vring_virtqueue::vring, VRING_DESC_F_NEXT, and wmb.

Referenced by vring_get_buf().

{
   struct vring *vr = &vq->vring;
   unsigned int i;

   /* find end of given descriptor */

   i = head;
   while (vr->desc[i].flags & VRING_DESC_F_NEXT)
           i = vr->desc[i].next;

   /* link it with free list and point to it */

   vr->desc[i].next = vq->free_head;
   wmb();
   vq->free_head = head;
}

int vring_get_buf	(	struct vring_virtqueue *	vq,
		unsigned int *	len
	)

Definition at line 60 of file virtio-ring.c.

References BUG_ON, vring_used_elem::id, id, vring_virtqueue::last_used_idx, vring_used_elem::len, NULL, vring::num, vring_used::ring, u32, vring::used, vring_virtqueue::vdata, vring_virtqueue::vring, vring_detach(), vring_more_used(), and wmb.

Referenced by virtnet_poll(), and virtnet_transmit().

{
   struct vring *vr = &vq->vring;
   struct vring_used_elem *elem;
   u32 id;
   int ret;

   BUG_ON(!vring_more_used(vq));

   elem = &vr->used->ring[vq->last_used_idx % vr->num];
   wmb();
   id = elem->id;
   if (len != NULL)
           *len = elem->len;

   ret = vq->vdata[id];

   vring_detach(vq, id);

   vq->last_used_idx++;

   return ret;
}

void vring_add_buf	(	struct vring_virtqueue *	vq,
		struct vring_list	list[],
		unsigned int	out,
		unsigned int	in,
		int	index,
		int	num_added
	)

Definition at line 84 of file virtio-ring.c.

References vring_list::addr, vring_desc::addr, vring::avail, BUG_ON, vring::desc, vring_desc::flags, vring_virtqueue::free_head, vring_avail::idx, vring_desc::len, vring_list::length, vring_desc::next, vring::num, vring_avail::ring, vring_virtqueue::vdata, virt_to_phys(), vring_virtqueue::vring, VRING_DESC_F_NEXT, VRING_DESC_F_WRITE, and wmb.

Referenced by provide_buffers(), virtnet_poll(), and virtnet_transmit().

{
   struct vring *vr = &vq->vring;
   int i, avail, head, prev;

   BUG_ON(out + in == 0);

   prev = 0;
   head = vq->free_head;
   for (i = head; out; i = vr->desc[i].next, out--) {

           vr->desc[i].flags = VRING_DESC_F_NEXT;
           vr->desc[i].addr = (u64)virt_to_phys(list->addr);
           vr->desc[i].len = list->length;
           prev = i;
           list++;
   }
   for ( ; in; i = vr->desc[i].next, in--) {

           vr->desc[i].flags = VRING_DESC_F_NEXT|VRING_DESC_F_WRITE;
           vr->desc[i].addr = (u64)virt_to_phys(list->addr);
           vr->desc[i].len = list->length;
           prev = i;
           list++;
   }
   vr->desc[prev].flags &= ~VRING_DESC_F_NEXT;

   vq->free_head = i;

   vq->vdata[head] = index;

   avail = (vr->avail->idx + num_added) % vr->num;
   vr->avail->ring[avail] = head;
   wmb();
}

void vring_kick	(	unsigned int	ioaddr,
		struct vring_virtqueue *	vq,
		int	num_added
	)

Definition at line 123 of file virtio-ring.c.

References vring::avail, vring_used::flags, vring_avail::idx, mb(), vring_virtqueue::queue_index, vring::used, vp_notify(), vring_virtqueue::vring, VRING_USED_F_NO_NOTIFY, and wmb.

Referenced by provide_buffers(), virtnet_poll(), and virtnet_transmit().

{
   struct vring *vr = &vq->vring;

   wmb();
   vr->avail->idx += num_added;

   mb();
   if (!(vr->used->flags & VRING_USED_F_NO_NOTIFY))
           vp_notify(ioaddr, vq->queue_index);
}