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Commit 0e575f85 authored by Arthur Kiyanovski's avatar Arthur Kiyanovski Committed by David S. Miller
Browse files

net: ena: minor performance improvement 



Reduce fastpath overhead by making ena_com_tx_comp_req_id_get() inline.
Also move it to ena_eth_com.h file with its dependency function
ena_com_cq_inc_head().

Signed-off-by: default avatarArthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7b68b836

drivers/net/ethernet/amazon/ena/ena_eth_com.c

+0 −43
Original line number Diff line number Diff line
@@ -59,15 +59,6 @@ static inline struct ena_eth_io_rx_cdesc_base *ena_com_get_next_rx_cdesc( 
	return cdesc;

}



static inline void ena_com_cq_inc_head(struct ena_com_io_cq *io_cq)

{

	io_cq->head++;



	/* Switch phase bit in case of wrap around */

	if (unlikely((io_cq->head & (io_cq->q_depth - 1)) == 0))

		io_cq->phase ^= 1;

}



static inline void *get_sq_desc(struct ena_com_io_sq *io_sq)

{

	u16 tail_masked;
@@ -477,40 +468,6 @@ int ena_com_add_single_rx_desc(struct ena_com_io_sq *io_sq, 
	return 0;

}



int ena_com_tx_comp_req_id_get(struct ena_com_io_cq *io_cq, u16 *req_id)

{

	u8 expected_phase, cdesc_phase;

	struct ena_eth_io_tx_cdesc *cdesc;

	u16 masked_head;



	masked_head = io_cq->head & (io_cq->q_depth - 1);

	expected_phase = io_cq->phase;



	cdesc = (struct ena_eth_io_tx_cdesc *)

		((uintptr_t)io_cq->cdesc_addr.virt_addr +

		(masked_head * io_cq->cdesc_entry_size_in_bytes));



	/* When the current completion descriptor phase isn't the same as the

	 * expected, it mean that the device still didn't update

	 * this completion.

	 */

	cdesc_phase = READ_ONCE(cdesc->flags) & ENA_ETH_IO_TX_CDESC_PHASE_MASK;

	if (cdesc_phase != expected_phase)

		return -EAGAIN;



	dma_rmb();

	if (unlikely(cdesc->req_id >= io_cq->q_depth)) {

		pr_err("Invalid req id %d\n", cdesc->req_id);

		return -EINVAL;

	}



	ena_com_cq_inc_head(io_cq);



	*req_id = READ_ONCE(cdesc->req_id);



	return 0;

}



bool ena_com_cq_empty(struct ena_com_io_cq *io_cq)

{

	struct ena_eth_io_rx_cdesc_base *cdesc;

drivers/net/ethernet/amazon/ena/ena_eth_com.h

+44 −2
Original line number Diff line number Diff line
@@ -86,8 +86,6 @@ int ena_com_add_single_rx_desc(struct ena_com_io_sq *io_sq, 
			       struct ena_com_buf *ena_buf,

			       u16 req_id);



int ena_com_tx_comp_req_id_get(struct ena_com_io_cq *io_cq, u16 *req_id);



bool ena_com_cq_empty(struct ena_com_io_cq *io_cq);



static inline void ena_com_unmask_intr(struct ena_com_io_cq *io_cq,
@@ -159,4 +157,48 @@ static inline void ena_com_comp_ack(struct ena_com_io_sq *io_sq, u16 elem) 
	io_sq->next_to_comp += elem;

}



static inline void ena_com_cq_inc_head(struct ena_com_io_cq *io_cq)

{

	io_cq->head++;



	/* Switch phase bit in case of wrap around */

	if (unlikely((io_cq->head & (io_cq->q_depth - 1)) == 0))

		io_cq->phase ^= 1;

}



static inline int ena_com_tx_comp_req_id_get(struct ena_com_io_cq *io_cq,

					     u16 *req_id)

{

	u8 expected_phase, cdesc_phase;

	struct ena_eth_io_tx_cdesc *cdesc;

	u16 masked_head;



	masked_head = io_cq->head & (io_cq->q_depth - 1);

	expected_phase = io_cq->phase;



	cdesc = (struct ena_eth_io_tx_cdesc *)

		((uintptr_t)io_cq->cdesc_addr.virt_addr +

		(masked_head * io_cq->cdesc_entry_size_in_bytes));



	/* When the current completion descriptor phase isn't the same as the

	 * expected, it mean that the device still didn't update

	 * this completion.

	 */

	cdesc_phase = READ_ONCE(cdesc->flags) & ENA_ETH_IO_TX_CDESC_PHASE_MASK;

	if (cdesc_phase != expected_phase)

		return -EAGAIN;



	dma_rmb();



	*req_id = READ_ONCE(cdesc->req_id);

	if (unlikely(*req_id >= io_cq->q_depth)) {

		pr_err("Invalid req id %d\n", cdesc->req_id);

		return -EINVAL;

	}



	ena_com_cq_inc_head(io_cq);



	return 0;

}



#endif /* ENA_ETH_COM_H_ */