From: Arthur Kiyanovski Date: Thu, 11 Oct 2018 11:26:16 +0300 Subject: [PATCH 02/19] net: ena: minor performance improvement Origin: https://git.kernel.org/linus/0e575f8542d1f4d74df30b5a9ba419c5373d01a1 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: Arthur Kiyanovski Signed-off-by: David S. Miller --- drivers/net/ethernet/amazon/ena/ena_eth_com.c | 43 ----------------- drivers/net/ethernet/amazon/ena/ena_eth_com.h | 46 ++++++++++++++++++- 2 files changed, 44 insertions(+), 45 deletions(-) Index: linux/drivers/net/ethernet/amazon/ena/ena_eth_com.c =================================================================== --- linux.orig/drivers/net/ethernet/amazon/ena/ena_eth_com.c +++ linux/drivers/net/ethernet/amazon/ena/ena_eth_com.c @@ -59,15 +59,6 @@ static inline struct ena_eth_io_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; @@ -476,40 +467,6 @@ int ena_com_add_single_rx_desc(struct en 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) { Index: linux/drivers/net/ethernet/amazon/ena/ena_eth_com.h =================================================================== --- linux.orig/drivers/net/ethernet/amazon/ena/ena_eth_com.h +++ linux/drivers/net/ethernet/amazon/ena/ena_eth_com.h @@ -86,8 +86,6 @@ int ena_com_add_single_rx_desc(struct en 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(stru 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_ */