Ejemplo n.º 1
0
void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
		   unsigned int len, bool checksummed, bool discard)
{
	struct efx_nic *efx = rx_queue->efx;
	struct efx_rx_buffer *rx_buf;
	bool leak_packet = false;

	rx_buf = efx_rx_buffer(rx_queue, index);
	EFX_BUG_ON_PARANOID(!rx_buf->data);
	EFX_BUG_ON_PARANOID(rx_buf->skb && rx_buf->page);
	EFX_BUG_ON_PARANOID(!(rx_buf->skb || rx_buf->page));

	/* This allows the refill path to post another buffer.
	 * EFX_RXD_HEAD_ROOM ensures that the slot we are using
	 * isn't overwritten yet.
	 */
	rx_queue->removed_count++;

	/* Validate the length encoded in the event vs the descriptor pushed */
	efx_rx_packet__check_len(rx_queue, rx_buf, len,
				 &discard, &leak_packet);

	EFX_TRACE(efx, "RX queue %d received id %x at %llx+%x %s%s\n",
		  rx_queue->queue, index,
		  (unsigned long long)rx_buf->dma_addr, len,
		  (checksummed ? " [SUMMED]" : ""),
		  (discard ? " [DISCARD]" : ""));

	/* Discard packet, if instructed to do so */
	if (unlikely(discard)) {
		if (unlikely(leak_packet))
			rx_queue->channel->n_skbuff_leaks++;
		else
			/* We haven't called efx_unmap_rx_buffer yet,
			 * so fini the entire rx_buffer here */
			efx_fini_rx_buffer(rx_queue, rx_buf);
		return;
	}

	/* Release card resources - assumes all RX buffers consumed in-order
	 * per RX queue
	 */
	efx_unmap_rx_buffer(efx, rx_buf);

	/* Prefetch nice and early so data will (hopefully) be in cache by
	 * the time we look at it.
	 */
	prefetch(rx_buf->data);

	/* Pipeline receives so that we give time for packet headers to be
	 * prefetched into cache.
	 */
	rx_buf->len = len;
	if (rx_queue->channel->rx_pkt)
		__efx_rx_packet(rx_queue->channel,
				rx_queue->channel->rx_pkt,
				rx_queue->channel->rx_pkt_csummed);
	rx_queue->channel->rx_pkt = rx_buf;
	rx_queue->channel->rx_pkt_csummed = checksummed;
}
Ejemplo n.º 2
0
void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
		   unsigned int n_frags, unsigned int len, u16 flags)
{
	struct efx_nic *efx = rx_queue->efx;
	struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
	struct efx_rx_buffer *rx_buf;

	rx_buf = efx_rx_buffer(rx_queue, index);
	rx_buf->flags |= flags;

	/* Validate the number of fragments and completed length */
	if (n_frags == 1) {
		efx_rx_packet__check_len(rx_queue, rx_buf, len);
	} else if (unlikely(n_frags > EFX_RX_MAX_FRAGS) ||
		   unlikely(len <= (n_frags - 1) * EFX_RX_USR_BUF_SIZE) ||
		   unlikely(len > n_frags * EFX_RX_USR_BUF_SIZE) ||
		   unlikely(!efx->rx_scatter)) {
		/* If this isn't an explicit discard request, either
		 * the hardware or the driver is broken.
		 */
		WARN_ON(!(len == 0 && rx_buf->flags & EFX_RX_PKT_DISCARD));
		rx_buf->flags |= EFX_RX_PKT_DISCARD;
	}

	netif_vdbg(efx, rx_status, efx->net_dev,
		   "RX queue %d received ids %x-%x len %d %s%s\n",
		   efx_rx_queue_index(rx_queue), index,
		   (index + n_frags - 1) & rx_queue->ptr_mask, len,
		   (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
		   (rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : "");

	/* Discard packet, if instructed to do so.  Process the
	 * previous receive first.
	 */
	if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) {
		efx_rx_flush_packet(channel);
		efx_discard_rx_packet(channel, rx_buf, n_frags);
		return;
	}

	if (n_frags == 1)
		rx_buf->len = len;

	/* Release and/or sync the DMA mapping - assumes all RX buffers
	 * consumed in-order per RX queue.
	 */
	efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);

	/* Prefetch nice and early so data will (hopefully) be in cache by
	 * the time we look at it.
	 */
	prefetch(efx_rx_buf_va(rx_buf));

	rx_buf->page_offset += efx->type->rx_buffer_hash_size;
	rx_buf->len -= efx->type->rx_buffer_hash_size;

	if (n_frags > 1) {
		/* Release/sync DMA mapping for additional fragments.
		 * Fix length for last fragment.
		 */
		unsigned int tail_frags = n_frags - 1;

		for (;;) {
			rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
			if (--tail_frags == 0)
				break;
			efx_sync_rx_buffer(efx, rx_buf, EFX_RX_USR_BUF_SIZE);
		}
		rx_buf->len = len - (n_frags - 1) * EFX_RX_USR_BUF_SIZE;
		efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
	}

	/* All fragments have been DMA-synced, so recycle pages. */
	rx_buf = efx_rx_buffer(rx_queue, index);
	efx_recycle_rx_pages(channel, rx_buf, n_frags);

	/* Pipeline receives so that we give time for packet headers to be
	 * prefetched into cache.
	 */
	efx_rx_flush_packet(channel);
	channel->rx_pkt_n_frags = n_frags;
	channel->rx_pkt_index = index;
}