/*
* Put user bytes into a free packet buffer, forward this packet to the TX
* queue, and return OK. If there are no free packet buffers, return SUSPEND.
*/
static int
virtio_net_send(struct netdriver_data * data, size_t len)
{
struct vumap_phys phys[2];
struct packet *p;
if (STAILQ_EMPTY(&free_list))
return SUSPEND;
p = STAILQ_FIRST(&free_list);
STAILQ_REMOVE_HEAD(&free_list, next);
if (len > MAX_PACK_SIZE)
panic("%s: packet too large to send: %zu", name, len);
netdriver_copyin(data, 0, p->vdata, len);
phys[0].vp_addr = p->phdr;
assert(!(phys[0].vp_addr & 1));
phys[0].vp_size = sizeof(struct virtio_net_hdr);
phys[1].vp_addr = p->pdata;
assert(!(phys[1].vp_addr & 1));
phys[1].vp_size = len;
virtio_to_queue(net_dev, TX_Q, phys, 2, p);
return OK;
}
/*============================================================================*
* lan8710a_send *
*============================================================================*/
static int
lan8710a_send(struct netdriver_data * data, size_t size)
{
lan8710a_t *e = &lan8710a_state;
lan8710a_desc_t *p_tx_desc;
u8_t *buf;
/* setup descriptors */
p_tx_desc = &(e->tx_desc[e->tx_desc_idx]);
/*
* Check if descriptor is available for host and suspend if not.
*/
if (LAN8710A_DESC_FLAG_OWN & p_tx_desc->pkt_len_flags)
return SUSPEND;
/* Drop packets that exceed the size of our transmission buffer. */
if (size > LAN8710A_IOBUF_SIZE) {
printf("%s: dropping large packet (%zu)\n",
netdriver_name(), size);
return OK;
}
/* virtual address of buffer */
buf = e->p_tx_buf + e->tx_desc_idx * LAN8710A_IOBUF_SIZE;
netdriver_copyin(data, 0, buf, size);
/* set descriptor length */
p_tx_desc->buffer_length_off = size;
/* set flags */
p_tx_desc->pkt_len_flags = (LAN8710A_DESC_FLAG_OWN |
LAN8710A_DESC_FLAG_SOP |
LAN8710A_DESC_FLAG_EOP |
TX_DESC_TO_PORT1 |
TX_DESC_TO_PORT_EN);
p_tx_desc->pkt_len_flags |= size;
/* setup DMA transfer */
lan8710a_dma_config_tx(e->tx_desc_idx);
e->tx_desc_idx++;
if (LAN8710A_NUM_TX_DESC == e->tx_desc_idx)
e->tx_desc_idx = 0;
return OK;
}
/*
* Try to send a packet.
*/
static int
e1000_send(struct netdriver_data * data, size_t size)
{
e1000_t *e;
e1000_tx_desc_t *desc;
unsigned int head, tail, next;
char *ptr;
e = &e1000_state;
if (size > E1000_IOBUF_SIZE)
panic("packet too large to send");
/*
* The queue tail must not advance to the point that it is equal to the
* queue head, since this condition indicates that the queue is empty.
*/
head = e1000_reg_read(e, E1000_REG_TDH);
tail = e1000_reg_read(e, E1000_REG_TDT);
next = (tail + 1) % e->tx_desc_count;
if (next == head)
return SUSPEND;
/* The descriptor to use is the one pointed to by the current tail. */
desc = &e->tx_desc[tail];
/* Copy the packet from the caller. */
ptr = e->tx_buffer + tail * E1000_IOBUF_SIZE;
netdriver_copyin(data, 0, ptr, size);
/* Mark this descriptor ready. */
desc->status = 0;
desc->length = size;
desc->command = E1000_TX_CMD_EOP | E1000_TX_CMD_FCS | E1000_TX_CMD_RS;
/* Increment tail. Start transmission. */
e1000_reg_write(e, E1000_REG_TDT, next);
return OK;
}
