/* Attempt to recycle the page if there is an RX recycle ring; the page can
* only be added if this is the final RX buffer, to prevent pages being used in
* the descriptor ring and appearing in the recycle ring simultaneously.
*/
static void efx_recycle_rx_page(struct efx_channel *channel,
struct efx_rx_buffer *rx_buf)
{
struct page *page = rx_buf->page;
struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
struct efx_nic *efx = rx_queue->efx;
unsigned index;
/* Only recycle the page after processing the final buffer. */
if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
return;
index = rx_queue->page_add & rx_queue->page_ptr_mask;
if (rx_queue->page_ring[index] == NULL) {
unsigned read_index = rx_queue->page_remove &
rx_queue->page_ptr_mask;
/* The next slot in the recycle ring is available, but
* increment page_remove if the read pointer currently
* points here.
*/
if (read_index == index)
++rx_queue->page_remove;
rx_queue->page_ring[index] = page;
++rx_queue->page_add;
return;
}
++rx_queue->page_recycle_full;
efx_unmap_rx_buffer(efx, rx_buf);
put_page(rx_buf->page);
}
static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,
struct efx_rx_buffer *rx_buf,
unsigned int n_frags)
{
struct sk_buff *skb;
u16 hdr_len = min_t(u16, rx_buf->len, EFX_SKB_HEADERS);
skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
if (unlikely(skb == NULL)) {
struct efx_rx_queue *rx_queue;
rx_queue = efx_channel_get_rx_queue(channel);
efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
return;
}
skb_record_rx_queue(skb, channel->rx_queue.core_index);
/* Set the SKB flags */
skb_checksum_none_assert(skb);
if (likely(rx_buf->flags & EFX_RX_PKT_CSUMMED))
skb->ip_summed = CHECKSUM_UNNECESSARY;
efx_rx_skb_attach_timestamp(channel, skb);
if (channel->type->receive_skb)
if (channel->type->receive_skb(channel, skb))
return;
/* Pass the packet up */
netif_receive_skb(skb);
}
static void efx_discard_rx_packet(struct efx_channel *channel,
struct efx_rx_buffer *rx_buf,
unsigned int n_frags)
{
struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
efx_recycle_rx_pages(channel, rx_buf, n_frags);
efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
}
/* Recycle the pages that are used by buffers that have just been received. */
static void efx_recycle_rx_pages(struct efx_channel *channel,
struct efx_rx_buffer *rx_buf,
unsigned int n_frags)
{
struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
do {
efx_recycle_rx_page(channel, rx_buf);
rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
} while (--n_frags);
}
/* Pass a received packet up through GRO. GRO can handle pages
* regardless of checksum state and skbs with a good checksum.
*/
static void
efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
unsigned int n_frags, u8 *eh)
{
struct napi_struct *napi = &channel->napi_str;
gro_result_t gro_result;
struct efx_nic *efx = channel->efx;
struct sk_buff *skb;
skb = napi_get_frags(napi);
if (unlikely(!skb)) {
struct efx_rx_queue *rx_queue;
rx_queue = efx_channel_get_rx_queue(channel);
efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
return;
}
if (efx->net_dev->features & NETIF_F_RXHASH)
skb_set_hash(skb, efx_rx_buf_hash(efx, eh),
PKT_HASH_TYPE_L3);
skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
for (;;) {
skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
rx_buf->page, rx_buf->page_offset,
rx_buf->len);
rx_buf->page = NULL;
skb->len += rx_buf->len;
if (skb_shinfo(skb)->nr_frags == n_frags)
break;
rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
}
skb->data_len = skb->len;
skb->truesize += n_frags * efx->rx_buffer_truesize;
skb_record_rx_queue(skb, channel->rx_queue.core_index);
skb_mark_napi_id(skb, &channel->napi_str);
gro_result = napi_gro_frags(napi);
if (gro_result != GRO_DROP)
channel->irq_mod_score += 2;
}
/* Handle a received packet. Second half: Touches packet payload. */
void __efx_rx_packet(struct efx_channel *channel)
{
struct efx_nic *efx = channel->efx;
struct efx_rx_buffer *rx_buf =
efx_rx_buffer(&channel->rx_queue, channel->rx_pkt_index);
u8 *eh = efx_rx_buf_va(rx_buf);
/* Read length from the prefix if necessary. This already
* excludes the length of the prefix itself.
*/
if (rx_buf->flags & EFX_RX_PKT_PREFIX_LEN)
rx_buf->len = le16_to_cpup((__le16 *)
(eh + efx->rx_packet_len_offset));
/* If we're in loopback test, then pass the packet directly to the
* loopback layer, and free the rx_buf here
*/
if (unlikely(efx->loopback_selftest)) {
struct efx_rx_queue *rx_queue;
efx_loopback_rx_packet(efx, eh, rx_buf->len);
rx_queue = efx_channel_get_rx_queue(channel);
efx_free_rx_buffers(rx_queue, rx_buf,
channel->rx_pkt_n_frags);
goto out;
}
if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;
if ((rx_buf->flags & EFX_RX_PKT_TCP) && !channel->type->receive_skb &&
!efx_channel_busy_polling(channel))
efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh);
else
efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
out:
channel->rx_pkt_n_frags = 0;
}
