Skip to content

Commit

Permalink
Browse files Browse the repository at this point in the history
[virtio] Consolidate vring_get_buf() by using a buffer list to add to…
… the vring

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
  • Loading branch information
Laurent Vivier authored and Michael Brown committed Nov 19, 2008
1 parent 5dd5107 commit fc49421
Show file tree
Hide file tree
Showing 2 changed files with 50 additions and 41 deletions.
85 changes: 44 additions & 41 deletions src/drivers/net/virtio-net.c
Expand Up @@ -204,52 +204,36 @@ static int vring_get_buf(int queue_index, unsigned int *len)
return ret;
}

static void vring_add_buf(int queue_index, int index, int num_added)
static void vring_add_buf(int queue_index,
struct vring_list list[],
unsigned int out, unsigned int in,
int index, int num_added)
{
struct vring *vr = &vring[queue_index];
int i, avail, head;
int i, avail, head, prev;

BUG_ON(queue_index >= QUEUE_NB);
BUG_ON(out + in == 0);

prev = 0;
head = free_head[queue_index];
i = head;

if (queue_index == TX_INDEX) {

BUG_ON(index != 0);

/* add header into vring */
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(&tx_virtio_hdr);
vr->desc[i].len = sizeof(struct virtio_net_hdr);
i = vr->desc[i].next;

/* add frame buffer into vring */

vr->desc[i].flags = 0;
vr->desc[i].addr = (u64)virt_to_phys(&tx_eth_frame);
vr->desc[i].len = ETH_FRAME_LEN;
i = vr->desc[i].next;

} else if (queue_index == RX_INDEX) {

BUG_ON(index >= RX_BUF_NB);

/* add header into vring */
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(&rx_hdr[index]);
vr->desc[i].len = sizeof(struct virtio_net_hdr);
i = vr->desc[i].next;

/* add frame buffer into vring */

vr->desc[i].flags = VRING_DESC_F_WRITE;
vr->desc[i].addr = (u64)virt_to_phys(&rx_buffer[index]);
vr->desc[i].len = ETH_FRAME_LEN;
i = vr->desc[i].next;
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;

free_head[queue_index] = i;

Expand Down Expand Up @@ -306,6 +290,7 @@ static int virtnet_poll(struct nic *nic, int retrieve)
unsigned int len;
u16 token;
struct virtio_net_hdr *hdr;
struct vring_list list[2];

if (!vring_more_used(RX_INDEX))
return 0;
Expand All @@ -320,12 +305,17 @@ static int virtnet_poll(struct nic *nic, int retrieve)
hdr = &rx_hdr[token]; /* FIXME: check flags */
len -= sizeof(struct virtio_net_hdr);

nic->packetlen = len;
nic->packetlen = len;
memcpy(nic->packet, (char *)rx_buffer[token], nic->packetlen);

/* add buffer to desc */

vring_add_buf(RX_INDEX, token, 0);
list[0].addr = (char*)&rx_hdr[token];
list[0].length = sizeof(struct virtio_net_hdr);
list[1].addr = (char*)&rx_buffer[token];
list[1].length = ETH_FRAME_LEN;

vring_add_buf(RX_INDEX, list, 0, 2, token, 0);
vring_kick(nic, RX_INDEX, 1);

return 1;
Expand All @@ -342,6 +332,8 @@ static int virtnet_poll(struct nic *nic, int retrieve)
static void virtnet_transmit(struct nic *nic, const char *destaddr,
unsigned int type, unsigned int len, const char *data)
{
struct vring_list list[2];

/*
* from http://www.etherboot.org/wiki/dev/devmanual :
* "You do not need more than one transmit buffer."
Expand All @@ -365,7 +357,12 @@ static void virtnet_transmit(struct nic *nic, const char *destaddr,
tx_eth_frame.hdr.type = htons(type);
memcpy(tx_eth_frame.data, data, len);

vring_add_buf(TX_INDEX, 0, 0);
list[0].addr = (char*)&tx_virtio_hdr;
list[0].length = sizeof(struct virtio_net_hdr);
list[1].addr = (char*)&tx_eth_frame;
list[1].length = ETH_FRAME_LEN;

vring_add_buf(TX_INDEX, list, 2, 0, 0, 0);

vring_kick(nic, TX_INDEX, 1);

Expand Down Expand Up @@ -405,9 +402,15 @@ static void virtnet_irq(struct nic *nic __unused, irq_action_t action)
static void provide_buffers(struct nic *nic)
{
int i;

for (i = 0; i < RX_BUF_NB; i++)
vring_add_buf(RX_INDEX, i, i);
struct vring_list list[2];

for (i = 0; i < RX_BUF_NB; i++) {
list[0].addr = (char*)&rx_hdr[i];
list[0].length = sizeof(struct virtio_net_hdr);
list[1].addr = (char*)&rx_buffer[i];
list[1].length = ETH_FRAME_LEN;
vring_add_buf(RX_INDEX, list, 0, 2, i, i);
}

/* nofify */

Expand Down
6 changes: 6 additions & 0 deletions src/include/gpxe/virtio-ring.h
Expand Up @@ -58,6 +58,11 @@ struct vring {
struct vring_used *used;
};

struct vring_list {
char *addr;
unsigned int length;
};

static inline void vring_init(struct vring *vr,
unsigned int num, unsigned char *queue)
{
Expand Down Expand Up @@ -90,4 +95,5 @@ static inline void vring_init(struct vring *vr,
(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_ */

0 comments on commit fc49421

Please sign in to comment.