From d70446ee1f406ef4c6dd299a8482dc98ef07ed0e Mon Sep 17 00:00:00 2001 From: Ioana Ciornei Date: Mon, 29 Jun 2020 21:47:11 +0300 Subject: [PATCH] dpaa2-eth: send a scatter-gather FD instead of realloc-ing Instead of realloc-ing the skb on the Tx path when the provided headroom is smaller than the HW requirements, create a Scatter/Gather frame descriptor with only one entry. Remove the '[drv] tx realloc frames' counter exposed previously through ethtool since it is no longer used. Signed-off-by: Ioana Ciornei Signed-off-by: David S. Miller --- .../freescale/dpaa2/dpaa2-eth-debugfs.c | 7 +- .../net/ethernet/freescale/dpaa2/dpaa2-eth.c | 177 +++++++++++++++--- .../net/ethernet/freescale/dpaa2/dpaa2-eth.h | 9 +- .../ethernet/freescale/dpaa2/dpaa2-ethtool.c | 1 - 4 files changed, 160 insertions(+), 34 deletions(-) diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-debugfs.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-debugfs.c index 2880ca02d7e7..5cb357c74dec 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-debugfs.c +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-debugfs.c @@ -19,14 +19,14 @@ static int dpaa2_dbg_cpu_show(struct seq_file *file, void *offset) int i; seq_printf(file, "Per-CPU stats for %s\n", priv->net_dev->name); - seq_printf(file, "%s%16s%16s%16s%16s%16s%16s%16s%16s%16s\n", + seq_printf(file, "%s%16s%16s%16s%16s%16s%16s%16s%16s\n", "CPU", "Rx", "Rx Err", "Rx SG", "Tx", "Tx Err", "Tx conf", - "Tx SG", "Tx realloc", "Enq busy"); + "Tx SG", "Enq busy"); for_each_online_cpu(i) { stats = per_cpu_ptr(priv->percpu_stats, i); extras = per_cpu_ptr(priv->percpu_extras, i); - seq_printf(file, "%3d%16llu%16llu%16llu%16llu%16llu%16llu%16llu%16llu%16llu\n", + seq_printf(file, "%3d%16llu%16llu%16llu%16llu%16llu%16llu%16llu%16llu\n", i, stats->rx_packets, stats->rx_errors, @@ -35,7 +35,6 @@ static int dpaa2_dbg_cpu_show(struct seq_file *file, void *offset) stats->tx_errors, extras->tx_conf_frames, extras->tx_sg_frames, - extras->tx_reallocs, extras->tx_portal_busy); } diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c index 712bbfdbe7d7..4a264b75c035 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c @@ -685,6 +685,86 @@ dma_map_sg_failed: return err; } +/* Create a SG frame descriptor based on a linear skb. + * + * This function is used on the Tx path when the skb headroom is not large + * enough for the HW requirements, thus instead of realloc-ing the skb we + * create a SG frame descriptor with only one entry. + */ +static int build_sg_fd_single_buf(struct dpaa2_eth_priv *priv, + struct sk_buff *skb, + struct dpaa2_fd *fd) +{ + struct device *dev = priv->net_dev->dev.parent; + struct dpaa2_eth_sgt_cache *sgt_cache; + struct dpaa2_sg_entry *sgt; + struct dpaa2_eth_swa *swa; + dma_addr_t addr, sgt_addr; + void *sgt_buf = NULL; + int sgt_buf_size; + int err; + + /* Prepare the HW SGT structure */ + sgt_cache = this_cpu_ptr(priv->sgt_cache); + sgt_buf_size = priv->tx_data_offset + sizeof(struct dpaa2_sg_entry); + + if (sgt_cache->count == 0) + sgt_buf = kzalloc(sgt_buf_size + DPAA2_ETH_TX_BUF_ALIGN, + GFP_ATOMIC); + else + sgt_buf = sgt_cache->buf[--sgt_cache->count]; + if (unlikely(!sgt_buf)) + return -ENOMEM; + + sgt_buf = PTR_ALIGN(sgt_buf, DPAA2_ETH_TX_BUF_ALIGN); + sgt = (struct dpaa2_sg_entry *)(sgt_buf + priv->tx_data_offset); + + addr = dma_map_single(dev, skb->data, skb->len, DMA_BIDIRECTIONAL); + if (unlikely(dma_mapping_error(dev, addr))) { + err = -ENOMEM; + goto data_map_failed; + } + + /* Fill in the HW SGT structure */ + dpaa2_sg_set_addr(sgt, addr); + dpaa2_sg_set_len(sgt, skb->len); + dpaa2_sg_set_final(sgt, true); + + /* Store the skb backpointer in the SGT buffer */ + swa = (struct dpaa2_eth_swa *)sgt_buf; + swa->type = DPAA2_ETH_SWA_SINGLE; + swa->single.skb = skb; + swa->sg.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; + } + + 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, skb->len); + dpaa2_fd_set_ctrl(fd, FD_CTRL_PTA); + + if (priv->tx_tstamp && skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) + enable_tx_tstamp(fd, sgt_buf); + + return 0; + +sgt_map_failed: + dma_unmap_single(dev, addr, skb->len, DMA_BIDIRECTIONAL); +data_map_failed: + if (sgt_cache->count >= DPAA2_ETH_SGT_CACHE_SIZE) + kfree(sgt_buf); + else + sgt_cache->buf[sgt_cache->count++] = sgt_buf; + + return err; +} + /* Create a frame descriptor based on a linear skb */ static int build_single_fd(struct dpaa2_eth_priv *priv, struct sk_buff *skb, @@ -743,13 +823,16 @@ static void free_tx_fd(const struct dpaa2_eth_priv *priv, const struct dpaa2_fd *fd, bool in_napi) { struct device *dev = priv->net_dev->dev.parent; - dma_addr_t fd_addr; + dma_addr_t fd_addr, sg_addr; struct sk_buff *skb = NULL; unsigned char *buffer_start; struct dpaa2_eth_swa *swa; u8 fd_format = dpaa2_fd_get_format(fd); u32 fd_len = dpaa2_fd_get_len(fd); + struct dpaa2_eth_sgt_cache *sgt_cache; + struct dpaa2_sg_entry *sgt; + fd_addr = dpaa2_fd_get_addr(fd); buffer_start = dpaa2_iova_to_virt(priv->iommu_domain, fd_addr); swa = (struct dpaa2_eth_swa *)buffer_start; @@ -769,16 +852,29 @@ static void free_tx_fd(const struct dpaa2_eth_priv *priv, DMA_BIDIRECTIONAL); } } else if (fd_format == dpaa2_fd_sg) { - skb = swa->sg.skb; + if (swa->type == DPAA2_ETH_SWA_SG) { + skb = swa->sg.skb; + + /* Unmap the scatterlist */ + dma_unmap_sg(dev, swa->sg.scl, swa->sg.num_sg, + DMA_BIDIRECTIONAL); + kfree(swa->sg.scl); - /* Unmap the scatterlist */ - dma_unmap_sg(dev, swa->sg.scl, swa->sg.num_sg, - DMA_BIDIRECTIONAL); - kfree(swa->sg.scl); + /* Unmap the SGT buffer */ + dma_unmap_single(dev, fd_addr, swa->sg.sgt_size, + DMA_BIDIRECTIONAL); + } else { + skb = swa->single.skb; - /* Unmap the SGT buffer */ - dma_unmap_single(dev, fd_addr, swa->sg.sgt_size, - DMA_BIDIRECTIONAL); + /* Unmap the SGT Buffer */ + dma_unmap_single(dev, fd_addr, swa->single.sgt_size, + DMA_BIDIRECTIONAL); + + sgt = (struct dpaa2_sg_entry *)(buffer_start + + priv->tx_data_offset); + sg_addr = dpaa2_sg_get_addr(sgt); + dma_unmap_single(dev, sg_addr, skb->len, DMA_BIDIRECTIONAL); + } } else { netdev_dbg(priv->net_dev, "Invalid FD format\n"); return; @@ -808,8 +904,17 @@ static void free_tx_fd(const struct dpaa2_eth_priv *priv, } /* Free SGT buffer allocated on tx */ - if (fd_format != dpaa2_fd_single) - skb_free_frag(buffer_start); + if (fd_format != dpaa2_fd_single) { + sgt_cache = this_cpu_ptr(priv->sgt_cache); + if (swa->type == DPAA2_ETH_SWA_SG) { + skb_free_frag(buffer_start); + } else { + if (sgt_cache->count >= DPAA2_ETH_SGT_CACHE_SIZE) + kfree(buffer_start); + else + sgt_cache->buf[sgt_cache->count++] = buffer_start; + } + } /* Move on with skb release */ napi_consume_skb(skb, in_napi); @@ -833,22 +938,6 @@ static netdev_tx_t dpaa2_eth_tx(struct sk_buff *skb, struct net_device *net_dev) percpu_extras = this_cpu_ptr(priv->percpu_extras); needed_headroom = dpaa2_eth_needed_headroom(priv, skb); - if (skb_headroom(skb) < needed_headroom) { - struct sk_buff *ns; - - ns = skb_realloc_headroom(skb, needed_headroom); - if (unlikely(!ns)) { - percpu_stats->tx_dropped++; - goto err_alloc_headroom; - } - percpu_extras->tx_reallocs++; - - if (skb->sk) - skb_set_owner_w(ns, skb->sk); - - dev_kfree_skb(skb); - skb = ns; - } /* We'll be holding a back-reference to the skb until Tx Confirmation; * we don't want that overwritten by a concurrent Tx with a cloned skb. @@ -867,6 +956,10 @@ static netdev_tx_t dpaa2_eth_tx(struct sk_buff *skb, struct net_device *net_dev) err = build_sg_fd(priv, skb, &fd); percpu_extras->tx_sg_frames++; percpu_extras->tx_sg_bytes += skb->len; + } else if (skb_headroom(skb) < needed_headroom) { + err = build_sg_fd_single_buf(priv, skb, &fd); + percpu_extras->tx_sg_frames++; + percpu_extras->tx_sg_bytes += skb->len; } else { err = build_single_fd(priv, skb, &fd); } @@ -924,7 +1017,6 @@ static netdev_tx_t dpaa2_eth_tx(struct sk_buff *skb, struct net_device *net_dev) return NETDEV_TX_OK; err_build_fd: -err_alloc_headroom: dev_kfree_skb(skb); return NETDEV_TX_OK; @@ -1161,6 +1253,22 @@ static int refill_pool(struct dpaa2_eth_priv *priv, return 0; } +static void dpaa2_eth_sgt_cache_drain(struct dpaa2_eth_priv *priv) +{ + struct dpaa2_eth_sgt_cache *sgt_cache; + u16 count; + int k, i; + + for_each_online_cpu(k) { + sgt_cache = per_cpu_ptr(priv->sgt_cache, k); + count = sgt_cache->count; + + for (i = 0; i < count; i++) + kfree(sgt_cache->buf[i]); + sgt_cache->count = 0; + } +} + static int pull_channel(struct dpaa2_eth_channel *ch) { int err; @@ -1562,6 +1670,9 @@ static int dpaa2_eth_stop(struct net_device *net_dev) /* Empty the buffer pool */ drain_pool(priv); + /* Empty the Scatter-Gather Buffer cache */ + dpaa2_eth_sgt_cache_drain(priv); + return 0; } @@ -3846,6 +3957,13 @@ static int dpaa2_eth_probe(struct fsl_mc_device *dpni_dev) goto err_alloc_percpu_extras; } + priv->sgt_cache = alloc_percpu(*priv->sgt_cache); + if (!priv->sgt_cache) { + dev_err(dev, "alloc_percpu(sgt_cache) failed\n"); + err = -ENOMEM; + goto err_alloc_sgt_cache; + } + err = netdev_init(net_dev); if (err) goto err_netdev_init; @@ -3914,6 +4032,8 @@ err_poll_thread: err_alloc_rings: err_csum: err_netdev_init: + free_percpu(priv->sgt_cache); +err_alloc_sgt_cache: free_percpu(priv->percpu_extras); err_alloc_percpu_extras: free_percpu(priv->percpu_stats); @@ -3959,6 +4079,7 @@ static int dpaa2_eth_remove(struct fsl_mc_device *ls_dev) fsl_mc_free_irqs(ls_dev); free_rings(priv); + free_percpu(priv->sgt_cache); free_percpu(priv->percpu_stats); free_percpu(priv->percpu_extras); diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h index 2d7ada0f0dbd..9e4ceb92f240 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h @@ -125,6 +125,7 @@ struct dpaa2_eth_swa { union { struct { struct sk_buff *skb; + int sgt_size; } single; struct { struct sk_buff *skb; @@ -282,7 +283,6 @@ struct dpaa2_eth_drv_stats { __u64 tx_conf_bytes; __u64 tx_sg_frames; __u64 tx_sg_bytes; - __u64 tx_reallocs; __u64 rx_sg_frames; __u64 rx_sg_bytes; /* Enqueues retried due to portal busy */ @@ -395,6 +395,12 @@ struct dpaa2_eth_cls_rule { u8 in_use; }; +#define DPAA2_ETH_SGT_CACHE_SIZE 256 +struct dpaa2_eth_sgt_cache { + void *buf[DPAA2_ETH_SGT_CACHE_SIZE]; + u16 count; +}; + /* Driver private data */ struct dpaa2_eth_priv { struct net_device *net_dev; @@ -409,6 +415,7 @@ struct dpaa2_eth_priv { u8 num_channels; struct dpaa2_eth_channel *channel[DPAA2_ETH_MAX_DPCONS]; + struct dpaa2_eth_sgt_cache __percpu *sgt_cache; struct dpni_attr dpni_attrs; u16 dpni_ver_major; diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c index e88269fe3de7..c4cbbcaa9a3f 100644 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-ethtool.c @@ -43,7 +43,6 @@ static char dpaa2_ethtool_extras[][ETH_GSTRING_LEN] = { "[drv] tx conf bytes", "[drv] tx sg frames", "[drv] tx sg bytes", - "[drv] tx realloc frames", "[drv] rx sg frames", "[drv] rx sg bytes", "[drv] enqueue portal busy", -- 2.34.1