Commit 59e92bfe authored by Maciej Fijalkowski's avatar Maciej Fijalkowski Committed by Daniel Borkmann
Browse files

ice: xsk: Borrow xdp_tx_active logic from i40e 



One of the things that commit 5574ff7b ("i40e: optimize AF_XDP Tx
completion path") introduced was the @xdp_tx_active field. Its usage
from i40e can be adjusted to ice driver and give us positive performance
results.

If the descriptor that @next_dd points to has been sent by HW (its DD
bit is set), then we are sure that at least quarter of the ring is ready
to be cleaned. If @xdp_tx_active is 0 which means that related xdp_ring
is not used for XDP_{TX, REDIRECT} workloads, then we know how many XSK
entries should placed to completion queue, IOW walking through the ring
can be skipped.

Signed-off-by: default avatarMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarAlexander Lobakin <alexandr.lobakin@intel.com>
Acked-by: default avatarMagnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20220125160446.78976-9-maciej.fijalkowski@intel.com
parent 126cdfe1

drivers/net/ethernet/intel/ice/ice_txrx.h

+1 −0
Original line number Diff line number Diff line
@@ -333,6 +333,7 @@ struct ice_tx_ring { 
	spinlock_t tx_lock;

	u32 txq_teid;			/* Added Tx queue TEID */

	/* CL4 - 4th cacheline starts here */

	u16 xdp_tx_active;

#define ICE_TX_FLAGS_RING_XDP		BIT(0)

	u8 flags;

	u8 dcb_tc;			/* Traffic class of ring */

drivers/net/ethernet/intel/ice/ice_txrx_lib.c

+1 −0
Original line number Diff line number Diff line
@@ -302,6 +302,7 @@ int ice_xmit_xdp_ring(void *data, u16 size, struct ice_tx_ring *xdp_ring) 
	tx_desc->cmd_type_offset_bsz = ice_build_ctob(ICE_TX_DESC_CMD_EOP, 0,

						      size, 0);



	xdp_ring->xdp_tx_active++;

	i++;

	if (i == xdp_ring->count) {

		i = 0;

drivers/net/ethernet/intel/ice/ice_xsk.c

+12 −3
Original line number Diff line number Diff line
@@ -687,6 +687,7 @@ static void 
ice_clean_xdp_tx_buf(struct ice_tx_ring *xdp_ring, struct ice_tx_buf *tx_buf)

{

	xdp_return_frame((struct xdp_frame *)tx_buf->raw_buf);

	xdp_ring->xdp_tx_active--;

	dma_unmap_single(xdp_ring->dev, dma_unmap_addr(tx_buf, dma),

			 dma_unmap_len(tx_buf, len), DMA_TO_DEVICE);

	dma_unmap_len_set(tx_buf, len, 0);
@@ -703,9 +704,8 @@ static u16 ice_clean_xdp_irq_zc(struct ice_tx_ring *xdp_ring, int napi_budget) 
{

	u16 tx_thresh = ICE_RING_QUARTER(xdp_ring);

	int budget = napi_budget / tx_thresh;

	u16 ntc = xdp_ring->next_to_clean;

	u16 next_dd = xdp_ring->next_dd;

	u16 cleared_dds = 0;

	u16 ntc, cleared_dds = 0;



	do {

		struct ice_tx_desc *next_dd_desc;
@@ -721,6 +721,12 @@ static u16 ice_clean_xdp_irq_zc(struct ice_tx_ring *xdp_ring, int napi_budget) 


		cleared_dds++;

		xsk_frames = 0;

		if (likely(!xdp_ring->xdp_tx_active)) {

			xsk_frames = tx_thresh;

			goto skip;

		}



		ntc = xdp_ring->next_to_clean;



		for (i = 0; i < tx_thresh; i++) {

			tx_buf = &xdp_ring->tx_buf[ntc];
@@ -736,6 +742,10 @@ static u16 ice_clean_xdp_irq_zc(struct ice_tx_ring *xdp_ring, int napi_budget) 
			if (ntc >= xdp_ring->count)

				ntc = 0;

		}

skip:

		xdp_ring->next_to_clean += tx_thresh;

		if (xdp_ring->next_to_clean >= desc_cnt)

			xdp_ring->next_to_clean -= desc_cnt;

		if (xsk_frames)

			xsk_tx_completed(xdp_ring->xsk_pool, xsk_frames);

		next_dd_desc->cmd_type_offset_bsz = 0;
@@ -744,7 +754,6 @@ static u16 ice_clean_xdp_irq_zc(struct ice_tx_ring *xdp_ring, int napi_budget) 
			next_dd = tx_thresh - 1;

	} while (budget--);



	xdp_ring->next_to_clean = ntc;

	xdp_ring->next_dd = next_dd;



	return cleared_dds * tx_thresh;