From: Robert-Ionut Alexa Date: Tue, 18 Oct 2022 14:19:00 +0000 (+0300) Subject: net: dpaa2-eth: AF_XDP TX zero copy support X-Git-Tag: v6.2-rc1~99^2~394^2~1 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=4a7f6c5ac9e558b07a6cf9407ad28250b60980ab;p=tomoyo%2Ftomoyo-test1.git net: dpaa2-eth: AF_XDP TX zero copy support Add support in dpaa2-eth for packet processing on the Tx path using AF_XDP zero copy mode. The newly added dpaa2_xsk_tx() function will handle enqueuing AF_XDP Tx packets into the appropriate queue and update any necessary statistics. On a more detailed note, the dpaa2_xsk_tx_build_fd() function handles creating a Scatter-Gather frame descriptor with only one data buffer. This is needed because otherwise we would need to impose a headroom in the Tx buffer to store our software annotation structures. This tactic is already used on the normal data path of the dpaa2-eth driver, thus we are reusing the dpaa2_eth_sgt_get/dpaa2_eth_sgt_recycle functions in order to allocate and recycle the Scatter-Gather table buffers. In case we have reached the maximum number of Tx XSK packets to be sent in a NAPI cycle, we'll exit the dpaa2_eth_poll() and hope to be rescheduled again. On the XSK Tx confirmation path, we are just unmapping the SGT buffer and recycle it for further use. Signed-off-by: Robert-Ionut Alexa Signed-off-by: Ioana Ciornei Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c index 4c340f70f50e..31eebeae5d95 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c @@ -858,7 +858,7 @@ static void dpaa2_eth_enable_tx_tstamp(struct dpaa2_eth_priv *priv, } } -static void *dpaa2_eth_sgt_get(struct dpaa2_eth_priv *priv) +void *dpaa2_eth_sgt_get(struct dpaa2_eth_priv *priv) { struct dpaa2_eth_sgt_cache *sgt_cache; void *sgt_buf = NULL; @@ -880,7 +880,7 @@ static void *dpaa2_eth_sgt_get(struct dpaa2_eth_priv *priv) return sgt_buf; } -static void dpaa2_eth_sgt_recycle(struct dpaa2_eth_priv *priv, void *sgt_buf) +void dpaa2_eth_sgt_recycle(struct dpaa2_eth_priv *priv, void *sgt_buf) { struct dpaa2_eth_sgt_cache *sgt_cache; @@ -1115,9 +1115,10 @@ static int dpaa2_eth_build_single_fd(struct dpaa2_eth_priv *priv, * This can be called either from dpaa2_eth_tx_conf() or on the error path of * dpaa2_eth_tx(). */ -static void dpaa2_eth_free_tx_fd(struct dpaa2_eth_priv *priv, - struct dpaa2_eth_fq *fq, - const struct dpaa2_fd *fd, bool in_napi) +void dpaa2_eth_free_tx_fd(struct dpaa2_eth_priv *priv, + struct dpaa2_eth_channel *ch, + struct dpaa2_eth_fq *fq, + const struct dpaa2_fd *fd, bool in_napi) { struct device *dev = priv->net_dev->dev.parent; dma_addr_t fd_addr, sg_addr; @@ -1184,6 +1185,10 @@ static void dpaa2_eth_free_tx_fd(struct dpaa2_eth_priv *priv, if (!swa->tso.is_last_fd) should_free_skb = 0; + } else if (swa->type == DPAA2_ETH_SWA_XSK) { + /* Unmap the SGT Buffer */ + dma_unmap_single(dev, fd_addr, swa->xsk.sgt_size, + DMA_BIDIRECTIONAL); } else { skb = swa->single.skb; @@ -1201,6 +1206,12 @@ static void dpaa2_eth_free_tx_fd(struct dpaa2_eth_priv *priv, return; } + if (swa->type == DPAA2_ETH_SWA_XSK) { + ch->xsk_tx_pkts_sent++; + dpaa2_eth_sgt_recycle(priv, buffer_start); + return; + } + if (swa->type != DPAA2_ETH_SWA_XDP && in_napi) { fq->dq_frames++; fq->dq_bytes += fd_len; @@ -1375,7 +1386,7 @@ err_alloc_tso_hdr: err_sgt_get: /* Free all the other FDs that were already fully created */ for (i = 0; i < index; i++) - dpaa2_eth_free_tx_fd(priv, NULL, &fd_start[i], false); + dpaa2_eth_free_tx_fd(priv, NULL, NULL, &fd_start[i], false); return err; } @@ -1491,7 +1502,7 @@ static netdev_tx_t __dpaa2_eth_tx(struct sk_buff *skb, if (unlikely(err < 0)) { percpu_stats->tx_errors++; /* Clean up everything, including freeing the skb */ - dpaa2_eth_free_tx_fd(priv, fq, fd, false); + dpaa2_eth_free_tx_fd(priv, NULL, fq, fd, false); netdev_tx_completed_queue(nq, 1, fd_len); } else { percpu_stats->tx_packets += total_enqueued; @@ -1584,7 +1595,7 @@ static void dpaa2_eth_tx_conf(struct dpaa2_eth_priv *priv, /* Check frame errors in the FD field */ fd_errors = dpaa2_fd_get_ctrl(fd) & DPAA2_FD_TX_ERR_MASK; - dpaa2_eth_free_tx_fd(priv, fq, fd, true); + dpaa2_eth_free_tx_fd(priv, ch, fq, fd, true); if (likely(!fd_errors)) return; @@ -1929,6 +1940,7 @@ static int dpaa2_eth_poll(struct napi_struct *napi, int budget) struct dpaa2_eth_fq *fq, *txc_fq = NULL; struct netdev_queue *nq; int store_cleaned, work_done; + bool work_done_zc = false; struct list_head rx_list; int retries = 0; u16 flowid; @@ -1941,6 +1953,15 @@ static int dpaa2_eth_poll(struct napi_struct *napi, int budget) INIT_LIST_HEAD(&rx_list); ch->rx_list = &rx_list; + if (ch->xsk_zc) { + work_done_zc = dpaa2_xsk_tx(priv, ch); + /* If we reached the XSK Tx per NAPI threshold, we're done */ + if (work_done_zc) { + work_done = budget; + goto out; + } + } + do { err = dpaa2_eth_pull_channel(ch); if (unlikely(err)) @@ -1993,6 +2014,11 @@ static int dpaa2_eth_poll(struct napi_struct *napi, int budget) out: netif_receive_skb_list(ch->rx_list); + if (ch->xsk_tx_pkts_sent) { + xsk_tx_completed(ch->xsk_pool, ch->xsk_tx_pkts_sent); + ch->xsk_tx_pkts_sent = 0; + } + if (txc_fq && txc_fq->dq_frames) { nq = netdev_get_tx_queue(priv->net_dev, txc_fq->flowid); netdev_tx_completed_queue(nq, txc_fq->dq_frames, @@ -2989,7 +3015,11 @@ static void dpaa2_eth_cdan_cb(struct dpaa2_io_notification_ctx *ctx) /* Update NAPI statistics */ ch->stats.cdan++; - napi_schedule(&ch->napi); + /* NAPI can also be scheduled from the AF_XDP Tx path. Mark a missed + * so that it can be rescheduled again. + */ + if (!napi_if_scheduled_mark_missed(&ch->napi)) + napi_schedule(&ch->napi); } /* Allocate and configure a DPCON object */ diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h index 38f67b98865f..5d0fc432e5b2 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h @@ -53,6 +53,12 @@ */ #define DPAA2_ETH_TXCONF_PER_NAPI 256 +/* Maximum number of Tx frames to be processed in a single NAPI + * call when AF_XDP is running. Bind it to DPAA2_ETH_TXCONF_PER_NAPI + * to maximize the throughput. + */ +#define DPAA2_ETH_TX_ZC_PER_NAPI DPAA2_ETH_TXCONF_PER_NAPI + /* Buffer qouta per channel. We want to keep in check number of ingress frames * in flight: for small sized frames, congestion group taildrop may kick in * first; for large sizes, Rx FQ taildrop threshold will ensure only a @@ -154,6 +160,7 @@ struct dpaa2_eth_swa { } xdp; struct { struct xdp_buff *xdp_buff; + int sgt_size; } xsk; struct { struct sk_buff *skb; @@ -495,6 +502,7 @@ struct dpaa2_eth_channel { int recycled_bufs_cnt; bool xsk_zc; + int xsk_tx_pkts_sent; struct xsk_buff_pool *xsk_pool; struct dpaa2_eth_bp *bp; }; @@ -531,7 +539,7 @@ struct dpaa2_eth_trap_data { #define DPAA2_ETH_DEFAULT_COPYBREAK 512 -#define DPAA2_ETH_ENQUEUE_MAX_FDS 200 +#define DPAA2_ETH_ENQUEUE_MAX_FDS 256 struct dpaa2_eth_fds { struct dpaa2_fd array[DPAA2_ETH_ENQUEUE_MAX_FDS]; }; @@ -836,4 +844,16 @@ void dpaa2_eth_xdp_enqueue(struct dpaa2_eth_priv *priv, int dpaa2_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags); int dpaa2_xsk_setup_pool(struct net_device *dev, struct xsk_buff_pool *pool, u16 qid); +void dpaa2_eth_free_tx_fd(struct dpaa2_eth_priv *priv, + struct dpaa2_eth_channel *ch, + struct dpaa2_eth_fq *fq, + const struct dpaa2_fd *fd, bool in_napi); +bool dpaa2_xsk_tx(struct dpaa2_eth_priv *priv, + struct dpaa2_eth_channel *ch); + +/* SGT (Scatter-Gather Table) cache management */ +void *dpaa2_eth_sgt_get(struct dpaa2_eth_priv *priv); + +void dpaa2_eth_sgt_recycle(struct dpaa2_eth_priv *priv, void *sgt_buf); + #endif /* __DPAA2_H */ diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-xsk.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-xsk.c index 2df7bffec5a7..731318842054 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-xsk.c +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-xsk.c @@ -196,6 +196,7 @@ static int dpaa2_xsk_disable_pool(struct net_device *dev, u16 qid) ch->xsk_zc = false; ch->xsk_pool = NULL; + ch->xsk_tx_pkts_sent = 0; ch->bp = priv->bp[DPAA2_ETH_DEFAULT_BP_IDX]; dpaa2_eth_setup_consume_func(priv, ch, DPAA2_RX_FQ, dpaa2_eth_rx); @@ -325,3 +326,125 @@ int dpaa2_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags) return 0; } + +static int dpaa2_xsk_tx_build_fd(struct dpaa2_eth_priv *priv, + struct dpaa2_eth_channel *ch, + struct dpaa2_fd *fd, + struct xdp_desc *xdp_desc) +{ + struct device *dev = priv->net_dev->dev.parent; + struct dpaa2_sg_entry *sgt; + struct dpaa2_eth_swa *swa; + void *sgt_buf = NULL; + dma_addr_t sgt_addr; + int sgt_buf_size; + dma_addr_t addr; + int err = 0; + + /* Prepare the HW SGT structure */ + sgt_buf_size = priv->tx_data_offset + sizeof(struct dpaa2_sg_entry); + sgt_buf = dpaa2_eth_sgt_get(priv); + if (unlikely(!sgt_buf)) + return -ENOMEM; + sgt = (struct dpaa2_sg_entry *)(sgt_buf + priv->tx_data_offset); + + /* Get the address of the XSK Tx buffer */ + addr = xsk_buff_raw_get_dma(ch->xsk_pool, xdp_desc->addr); + xsk_buff_raw_dma_sync_for_device(ch->xsk_pool, addr, xdp_desc->len); + + /* Fill in the HW SGT structure */ + dpaa2_sg_set_addr(sgt, addr); + dpaa2_sg_set_len(sgt, xdp_desc->len); + dpaa2_sg_set_final(sgt, true); + + /* Store the necessary info in the SGT buffer */ + swa = (struct dpaa2_eth_swa *)sgt_buf; + swa->type = DPAA2_ETH_SWA_XSK; + swa->xsk.sgt_size = sgt_buf_size; + + /* Separately map the SGT buffer */ + sgt_addr = dma_map_single(dev, sgt_buf, sgt_buf_size, DMA_BIDIRECTIONAL); + if (unlikely(dma_mapping_error(dev, sgt_addr))) { + err = -ENOMEM; + goto sgt_map_failed; + } + + /* Initialize FD fields */ + memset(fd, 0, sizeof(struct dpaa2_fd)); + dpaa2_fd_set_offset(fd, priv->tx_data_offset); + dpaa2_fd_set_format(fd, dpaa2_fd_sg); + dpaa2_fd_set_addr(fd, sgt_addr); + dpaa2_fd_set_len(fd, xdp_desc->len); + dpaa2_fd_set_ctrl(fd, FD_CTRL_PTA); + + return 0; + +sgt_map_failed: + dpaa2_eth_sgt_recycle(priv, sgt_buf); + + return err; +} + +bool dpaa2_xsk_tx(struct dpaa2_eth_priv *priv, + struct dpaa2_eth_channel *ch) +{ + struct xdp_desc *xdp_descs = ch->xsk_pool->tx_descs; + struct dpaa2_eth_drv_stats *percpu_extras; + struct rtnl_link_stats64 *percpu_stats; + int budget = DPAA2_ETH_TX_ZC_PER_NAPI; + int total_enqueued, enqueued; + int retries, max_retries; + struct dpaa2_eth_fq *fq; + struct dpaa2_fd *fds; + int batch, i, err; + + percpu_stats = this_cpu_ptr(priv->percpu_stats); + percpu_extras = this_cpu_ptr(priv->percpu_extras); + fds = (this_cpu_ptr(priv->fd))->array; + + /* Use the FQ with the same idx as the affine CPU */ + fq = &priv->fq[ch->nctx.desired_cpu]; + + batch = xsk_tx_peek_release_desc_batch(ch->xsk_pool, budget); + if (!batch) + return false; + + /* Create a FD for each XSK frame to be sent */ + for (i = 0; i < batch; i++) { + err = dpaa2_xsk_tx_build_fd(priv, ch, &fds[i], &xdp_descs[i]); + if (err) { + batch = i; + break; + } + } + + /* Enqueue all the created FDs */ + max_retries = batch * DPAA2_ETH_ENQUEUE_RETRIES; + total_enqueued = 0; + enqueued = 0; + retries = 0; + while (total_enqueued < batch && retries < max_retries) { + err = priv->enqueue(priv, fq, &fds[total_enqueued], 0, + batch - total_enqueued, &enqueued); + if (err == -EBUSY) { + retries++; + continue; + } + + total_enqueued += enqueued; + } + percpu_extras->tx_portal_busy += retries; + + /* Update statistics */ + percpu_stats->tx_packets += total_enqueued; + for (i = 0; i < total_enqueued; i++) + percpu_stats->tx_bytes += dpaa2_fd_get_len(&fds[i]); + for (i = total_enqueued; i < batch; i++) { + dpaa2_eth_free_tx_fd(priv, ch, fq, &fds[i], false); + percpu_stats->tx_errors++; + } + + xsk_tx_release(ch->xsk_pool); + + return total_enqueued == budget ? true : false; +}