From: Andrew Rybchenko Date: Tue, 29 Nov 2016 16:19:18 +0000 (+0000) Subject: net/sfc: calculate Rx buffer size which may be used X-Git-Tag: spdx-start~5053 X-Git-Url: http://git.droids-corp.org/?p=dpdk.git;a=commitdiff_plain;h=0c7a0c35f24c1997be7e30d53c8486eb546ae13a net/sfc: calculate Rx buffer size which may be used Take Rx buffer start alignment and end-padding into account. Signed-off-by: Andrew Rybchenko Reviewed-by: Andy Moreton Reviewed-by: Ferruh Yigit --- diff --git a/drivers/net/sfc/sfc_rx.c b/drivers/net/sfc/sfc_rx.c index 00bcc9d932..0a37776242 100644 --- a/drivers/net/sfc/sfc_rx.c +++ b/drivers/net/sfc/sfc_rx.c @@ -66,6 +66,106 @@ sfc_rx_qcheck_conf(struct sfc_adapter *sa, return rc; } +static unsigned int +sfc_rx_mbuf_data_alignment(struct rte_mempool *mb_pool) +{ + uint32_t data_off; + uint32_t order; + + /* The mbuf object itself is always cache line aligned */ + order = rte_bsf32(RTE_CACHE_LINE_SIZE); + + /* Data offset from mbuf object start */ + data_off = sizeof(struct rte_mbuf) + rte_pktmbuf_priv_size(mb_pool) + + RTE_PKTMBUF_HEADROOM; + + order = MIN(order, rte_bsf32(data_off)); + + return 1u << (order - 1); +} + +static uint16_t +sfc_rx_mb_pool_buf_size(struct sfc_adapter *sa, struct rte_mempool *mb_pool) +{ + const efx_nic_cfg_t *encp = efx_nic_cfg_get(sa->nic); + const uint32_t nic_align_start = MAX(1, encp->enc_rx_buf_align_start); + const uint32_t nic_align_end = MAX(1, encp->enc_rx_buf_align_end); + uint16_t buf_size; + unsigned int buf_aligned; + unsigned int start_alignment; + unsigned int end_padding_alignment; + + /* Below it is assumed that both alignments are power of 2 */ + SFC_ASSERT(rte_is_power_of_2(nic_align_start)); + SFC_ASSERT(rte_is_power_of_2(nic_align_end)); + + /* + * mbuf is always cache line aligned, double-check + * that it meets rx buffer start alignment requirements. + */ + + /* Start from mbuf pool data room size */ + buf_size = rte_pktmbuf_data_room_size(mb_pool); + + /* Remove headroom */ + if (buf_size <= RTE_PKTMBUF_HEADROOM) { + sfc_err(sa, + "RxQ mbuf pool %s object data room size %u is smaller than headroom %u", + mb_pool->name, buf_size, RTE_PKTMBUF_HEADROOM); + return 0; + } + buf_size -= RTE_PKTMBUF_HEADROOM; + + /* Calculate guaranteed data start alignment */ + buf_aligned = sfc_rx_mbuf_data_alignment(mb_pool); + + /* Reserve space for start alignment */ + if (buf_aligned < nic_align_start) { + start_alignment = nic_align_start - buf_aligned; + if (buf_size <= start_alignment) { + sfc_err(sa, + "RxQ mbuf pool %s object data room size %u is insufficient for headroom %u and buffer start alignment %u required by NIC", + mb_pool->name, + rte_pktmbuf_data_room_size(mb_pool), + RTE_PKTMBUF_HEADROOM, start_alignment); + return 0; + } + buf_aligned = nic_align_start; + buf_size -= start_alignment; + } else { + start_alignment = 0; + } + + /* Make sure that end padding does not write beyond the buffer */ + if (buf_aligned < nic_align_end) { + /* + * Estimate space which can be lost. If guarnteed buffer + * size is odd, lost space is (nic_align_end - 1). More + * accurate formula is below. + */ + end_padding_alignment = nic_align_end - + MIN(buf_aligned, 1u << (rte_bsf32(buf_size) - 1)); + if (buf_size <= end_padding_alignment) { + sfc_err(sa, + "RxQ mbuf pool %s object data room size %u is insufficient for headroom %u, buffer start alignment %u and end padding alignment %u required by NIC", + mb_pool->name, + rte_pktmbuf_data_room_size(mb_pool), + RTE_PKTMBUF_HEADROOM, start_alignment, + end_padding_alignment); + return 0; + } + buf_size -= end_padding_alignment; + } else { + /* + * Start is aligned the same or better than end, + * just align length. + */ + buf_size = P2ALIGN(buf_size, nic_align_end); + } + + return buf_size; +} + int sfc_rx_qinit(struct sfc_adapter *sa, unsigned int sw_index, uint16_t nb_rx_desc, unsigned int socket_id, @@ -73,6 +173,7 @@ sfc_rx_qinit(struct sfc_adapter *sa, unsigned int sw_index, struct rte_mempool *mb_pool) { int rc; + uint16_t buf_size; struct sfc_rxq_info *rxq_info; unsigned int evq_index; struct sfc_evq *evq; @@ -82,10 +183,10 @@ sfc_rx_qinit(struct sfc_adapter *sa, unsigned int sw_index, if (rc != 0) goto fail_bad_conf; - if (rte_pktmbuf_data_room_size(mb_pool) <= RTE_PKTMBUF_HEADROOM) { - sfc_err(sa, "RxQ %u mbuf is too small, %u vs headroom %u", - sw_index, rte_pktmbuf_data_room_size(mb_pool), - RTE_PKTMBUF_HEADROOM); + buf_size = sfc_rx_mb_pool_buf_size(sa, mb_pool); + if (buf_size == 0) { + sfc_err(sa, "RxQ %u mbuf pool object size is too small", + sw_index); goto fail_bad_conf; } @@ -126,6 +227,7 @@ sfc_rx_qinit(struct sfc_adapter *sa, unsigned int sw_index, rxq->evq = evq; rxq->ptr_mask = rxq_info->entries - 1; rxq->refill_mb_pool = mb_pool; + rxq->buf_size = buf_size; rxq->hw_index = sw_index; rxq->state = SFC_RXQ_INITIALIZED; diff --git a/drivers/net/sfc/sfc_rx.h b/drivers/net/sfc/sfc_rx.h index b506d9aadc..9719eae764 100644 --- a/drivers/net/sfc/sfc_rx.h +++ b/drivers/net/sfc/sfc_rx.h @@ -71,6 +71,7 @@ struct sfc_rxq { unsigned int ptr_mask; /* Used on refill */ + uint16_t buf_size; struct rte_mempool *refill_mb_pool; efx_rxq_t *common; efsys_mem_t mem;