From patchwork Fri Dec 4 05:46:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sieng Piaw Liew X-Patchwork-Id: 1410850 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=DgNWdvkC; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CnMGM5K7vz9s0b for ; Fri, 4 Dec 2020 16:49:15 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728037AbgLDFtO (ORCPT ); Fri, 4 Dec 2020 00:49:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725372AbgLDFtO (ORCPT ); Fri, 4 Dec 2020 00:49:14 -0500 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DD8AC061A55 for ; Thu, 3 Dec 2020 21:48:28 -0800 (PST) Received: by mail-pg1-x542.google.com with SMTP id w16so2856995pga.9 for ; Thu, 03 Dec 2020 21:48:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=MYtDPZ0ZgubMcf7gzoslCdTpA8We1EfJtpn/Ol0OXwY=; b=DgNWdvkCyvwIKYZqqlxyemRoeaEB+WQcX/IPOEo6gi2MVCMGrt/4JqhDETgDNrCyHG qb+XKHTSQwzz1nefSNXEDad9gqQvF7Y13c8g+YJgWCkLYetFMlRDOiH5iud4CzvQdeyy x6XgZHaBtHd88RWAiyrjckfXxNwU61/LSeCaYuU7+W1bR+WRSnbf6+kj0kNfVpI+Hca3 IvD+H08/ALbgxKbBekQMynQqCLadeADeWRebbuaZayJbvyZvwqGd8ybCjSHtSLjUsCXV bp1r+QjD/ZmmmPKsOJvSRe9+fm6UF03jke9WOTCl+xjMGF6OvoKX/dlsMoQa2/q0jGHq Yg/g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=MYtDPZ0ZgubMcf7gzoslCdTpA8We1EfJtpn/Ol0OXwY=; b=dxbusZnnMDrkzoUa9p7hDUl7qTAeo8qNNfDqfqHshsQpbzwo7n+1fKnZ1NEc0cH4uo iitXWU9CFjAng4Y8k9bDIleV71cAQZagJsDIAq17cc75ybBOQeqSJ0V3PEkqje1tgLwv iFtLkoOxkU/NDEIyyqNWIl5CuTDsFNu+sxh1LWRWB0PRr+Eq+1RW23TQW4wEBE6sgsS2 A2Yx2Mfn/+pkmxz/rJTgBB1jElGy9iWEEdp2eKKoZe7Amzp8c8VQ3RsAcHvH4fd0doB7 72NtFxVMph7Ila9pJ7H7QC1Vn8DT1TMy2xQ8YBCfrPsHvA4VX/ibt1F4XOIYmgJ/hHp0 TdpA== X-Gm-Message-State: AOAM532qk0tpHlF6wcbsWPOSxVbmaLgys9n+0mc5Xj8L1U7rZ8wIkEJ6 mijN3Ags1IYfJxZFEcMl+HE= X-Google-Smtp-Source: ABdhPJxR1z0HzG37ENCM6NvveURynHAnAR9JxXjarCT+/39J/T/kO2G3wTa6Hlu4RYnaIytm69hgdw== X-Received: by 2002:a63:561f:: with SMTP id k31mr6070036pgb.227.1607060908194; Thu, 03 Dec 2020 21:48:28 -0800 (PST) Received: from DESKTOP-8REGVGF.localdomain ([211.25.125.254]) by smtp.gmail.com with ESMTPSA id u205sm3542134pfc.146.2020.12.03.21.48.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Dec 2020 21:48:27 -0800 (PST) From: Sieng Piaw Liew To: Florian Fainelli Cc: bcm-kernel-feedback-list@broadcom.com, Sieng Piaw Liew , netdev@vger.kernel.org Subject: [PATCH net-next] bcm63xx_enet: convert to build_skb Date: Fri, 4 Dec 2020 13:46:16 +0800 Message-Id: <20201204054616.26876-4-liew.s.piaw@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201204054616.26876-1-liew.s.piaw@gmail.com> References: <20201204054616.26876-1-liew.s.piaw@gmail.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org We can increase the efficiency of rx path by using buffers to receive packets then build SKBs around them just before passing into the network stack. In contrast, preallocating SKBs too early reduces CPU cache efficiency. Check if we're in NAPI context when refilling RX. Normally we're almost always running in NAPI context. Dispatch to napi_alloc_frag directly instead of relying on netdev_alloc_frag which still runs local_bh_disable/enable. Tested on BCM6328 320 MHz and iperf3 -M 512 to measure packet/sec performance. Included netif_receive_skb_list and NET_IP_ALIGN optimizations. Before: [ ID] Interval Transfer Bandwidth Retr [ 4] 0.00-10.00 sec 49.9 MBytes 41.9 Mbits/sec 197 sender [ 4] 0.00-10.00 sec 49.3 MBytes 41.3 Mbits/sec receiver After: [ ID] Interval Transfer Bandwidth Retr [ 4] 0.00-30.00 sec 171 MBytes 47.8 Mbits/sec 272 sender [ 4] 0.00-30.00 sec 170 MBytes 47.6 Mbits/sec receiver Signed-off-by: Sieng Piaw Liew --- drivers/net/ethernet/broadcom/bcm63xx_enet.c | 156 ++++++++----------- drivers/net/ethernet/broadcom/bcm63xx_enet.h | 14 +- 2 files changed, 79 insertions(+), 91 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.c b/drivers/net/ethernet/broadcom/bcm63xx_enet.c index 92bff4758216..4ace540f0c92 100644 --- a/drivers/net/ethernet/broadcom/bcm63xx_enet.c +++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.c @@ -220,7 +220,7 @@ static void bcm_enet_mdio_write_mii(struct net_device *dev, int mii_id, /* * refill rx queue */ -static int bcm_enet_refill_rx(struct net_device *dev) +static int bcm_enet_refill_rx(struct net_device *dev, bool napi_mode) { struct bcm_enet_priv *priv; @@ -228,29 +228,29 @@ static int bcm_enet_refill_rx(struct net_device *dev) while (priv->rx_desc_count < priv->rx_ring_size) { struct bcm_enet_desc *desc; - struct sk_buff *skb; - dma_addr_t p; int desc_idx; u32 len_stat; desc_idx = priv->rx_dirty_desc; desc = &priv->rx_desc_cpu[desc_idx]; - if (!priv->rx_skb[desc_idx]) { - if (priv->enet_is_sw) - skb = netdev_alloc_skb_ip_align(dev, priv->rx_skb_size); + if (!priv->rx_buf[desc_idx]) { + void *buf; + + if (likely(napi_mode)) + buf = napi_alloc_frag(priv->rx_frag_size); else - skb = netdev_alloc_skb(dev, priv->rx_skb_size); - if (!skb) + buf = netdev_alloc_frag(priv->rx_frag_size); + if (unlikely(!buf)) break; - priv->rx_skb[desc_idx] = skb; - p = dma_map_single(&priv->pdev->dev, skb->data, - priv->rx_skb_size, - DMA_FROM_DEVICE); - desc->address = p; + priv->rx_buf[desc_idx] = buf; + desc->address = dma_map_single(&priv->pdev->dev, + buf + priv->rx_buf_offset, + priv->rx_buf_size, + DMA_FROM_DEVICE); } - len_stat = priv->rx_skb_size << DMADESC_LENGTH_SHIFT; + len_stat = priv->rx_buf_size << DMADESC_LENGTH_SHIFT; len_stat |= DMADESC_OWNER_MASK; if (priv->rx_dirty_desc == priv->rx_ring_size - 1) { len_stat |= (DMADESC_WRAP_MASK >> priv->dma_desc_shift); @@ -290,7 +290,7 @@ static void bcm_enet_refill_rx_timer(struct timer_list *t) struct net_device *dev = priv->net_dev; spin_lock(&priv->rx_lock); - bcm_enet_refill_rx(dev); + bcm_enet_refill_rx(dev, false); spin_unlock(&priv->rx_lock); } @@ -320,6 +320,7 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget) int desc_idx; u32 len_stat; unsigned int len; + void *buf; desc_idx = priv->rx_curr_desc; desc = &priv->rx_desc_cpu[desc_idx]; @@ -365,16 +366,14 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget) } /* valid packet */ - skb = priv->rx_skb[desc_idx]; + buf = priv->rx_buf[desc_idx]; len = (len_stat & DMADESC_LENGTH_MASK) >> DMADESC_LENGTH_SHIFT; /* don't include FCS */ len -= 4; if (len < copybreak) { - struct sk_buff *nskb; - - nskb = napi_alloc_skb(&priv->napi, len); - if (!nskb) { + skb = napi_alloc_skb(&priv->napi, len); + if (unlikely(!skb)) { /* forget packet, just rearm desc */ dev->stats.rx_dropped++; continue; @@ -382,14 +381,20 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget) dma_sync_single_for_cpu(kdev, desc->address, len, DMA_FROM_DEVICE); - memcpy(nskb->data, skb->data, len); + memcpy(skb->data, buf + priv->rx_buf_offset, len); dma_sync_single_for_device(kdev, desc->address, len, DMA_FROM_DEVICE); - skb = nskb; } else { - dma_unmap_single(&priv->pdev->dev, desc->address, - priv->rx_skb_size, DMA_FROM_DEVICE); - priv->rx_skb[desc_idx] = NULL; + dma_unmap_single(kdev, desc->address, + priv->rx_buf_size, DMA_FROM_DEVICE); + skb = build_skb(buf, priv->rx_frag_size); + if (unlikely(!skb)) { + skb_free_frag(buf); + dev->stats.rx_dropped++; + continue; + } + priv->rx_buf[desc_idx] = NULL; + skb_reserve(skb, priv->rx_buf_offset); } skb_put(skb, len); @@ -403,7 +408,7 @@ static int bcm_enet_receive_queue(struct net_device *dev, int budget) netif_receive_skb_list(&rx_list); if (processed || !priv->rx_desc_count) { - bcm_enet_refill_rx(dev); + bcm_enet_refill_rx(dev, true); /* kick rx dma */ enet_dmac_writel(priv, priv->dma_chan_en_mask, @@ -859,6 +864,24 @@ static void bcm_enet_adjust_link(struct net_device *dev) priv->pause_tx ? "tx" : "off"); } +static void bcm_enet_free_rx_buf_ring(struct device *kdev, struct bcm_enet_priv *priv) +{ + int i; + + for (i = 0; i < priv->rx_ring_size; i++) { + struct bcm_enet_desc *desc; + + if (!priv->rx_buf[i]) + continue; + + desc = &priv->rx_desc_cpu[i]; + dma_unmap_single(kdev, desc->address, priv->rx_buf_size, + DMA_FROM_DEVICE); + skb_free_frag(priv->rx_buf[i]); + } + kfree(priv->rx_buf); +} + /* * open callback, allocate dma rings & buffers and start rx operation */ @@ -968,10 +991,10 @@ static int bcm_enet_open(struct net_device *dev) priv->tx_curr_desc = 0; spin_lock_init(&priv->tx_lock); - /* init & fill rx ring with skbs */ - priv->rx_skb = kcalloc(priv->rx_ring_size, sizeof(struct sk_buff *), + /* init & fill rx ring with buffers */ + priv->rx_buf = kcalloc(priv->rx_ring_size, sizeof(void *), GFP_KERNEL); - if (!priv->rx_skb) { + if (!priv->rx_buf) { ret = -ENOMEM; goto out_free_tx_skb; } @@ -988,7 +1011,7 @@ static int bcm_enet_open(struct net_device *dev) enet_dmac_writel(priv, ENETDMA_BUFALLOC_FORCE_MASK | 0, ENETDMAC_BUFALLOC, priv->rx_chan); - if (bcm_enet_refill_rx(dev)) { + if (bcm_enet_refill_rx(dev, false)) { dev_err(kdev, "cannot allocate rx skb queue\n"); ret = -ENOMEM; goto out; @@ -1084,18 +1107,7 @@ static int bcm_enet_open(struct net_device *dev) return 0; out: - for (i = 0; i < priv->rx_ring_size; i++) { - struct bcm_enet_desc *desc; - - if (!priv->rx_skb[i]) - continue; - - desc = &priv->rx_desc_cpu[i]; - dma_unmap_single(kdev, desc->address, priv->rx_skb_size, - DMA_FROM_DEVICE); - kfree_skb(priv->rx_skb[i]); - } - kfree(priv->rx_skb); + bcm_enet_free_rx_buf_ring(kdev, priv); out_free_tx_skb: kfree(priv->tx_skb); @@ -1174,7 +1186,6 @@ static int bcm_enet_stop(struct net_device *dev) { struct bcm_enet_priv *priv; struct device *kdev; - int i; priv = netdev_priv(dev); kdev = &priv->pdev->dev; @@ -1201,21 +1212,10 @@ static int bcm_enet_stop(struct net_device *dev) /* force reclaim of all tx buffers */ bcm_enet_tx_reclaim(dev, 1); - /* free the rx skb ring */ - for (i = 0; i < priv->rx_ring_size; i++) { - struct bcm_enet_desc *desc; - - if (!priv->rx_skb[i]) - continue; - - desc = &priv->rx_desc_cpu[i]; - dma_unmap_single(kdev, desc->address, priv->rx_skb_size, - DMA_FROM_DEVICE); - kfree_skb(priv->rx_skb[i]); - } + /* free the rx buffer ring */ + bcm_enet_free_rx_buf_ring(kdev, priv); /* free remaining allocated memory */ - kfree(priv->rx_skb); kfree(priv->tx_skb); dma_free_coherent(kdev, priv->rx_desc_alloc_size, priv->rx_desc_cpu, priv->rx_desc_dma); @@ -1637,9 +1637,12 @@ static int bcm_enet_change_mtu(struct net_device *dev, int new_mtu) * align rx buffer size to dma burst len, account FCS since * it's appended */ - priv->rx_skb_size = ALIGN(actual_mtu + ETH_FCS_LEN, + priv->rx_buf_size = ALIGN(actual_mtu + ETH_FCS_LEN, priv->dma_maxburst * 4); + priv->rx_frag_size = SKB_DATA_ALIGN(priv->rx_buf_size + priv->rx_buf_offset) + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + dev->mtu = new_mtu; return 0; } @@ -1724,6 +1727,7 @@ static int bcm_enet_probe(struct platform_device *pdev) priv->enet_is_sw = false; priv->dma_maxburst = BCMENET_DMA_MAXBURST; + priv->rx_buf_offset = NET_SKB_PAD; ret = bcm_enet_change_mtu(dev, dev->mtu); if (ret) @@ -2151,10 +2155,10 @@ static int bcm_enetsw_open(struct net_device *dev) priv->tx_curr_desc = 0; spin_lock_init(&priv->tx_lock); - /* init & fill rx ring with skbs */ - priv->rx_skb = kcalloc(priv->rx_ring_size, sizeof(struct sk_buff *), + /* init & fill rx ring with buffers */ + priv->rx_buf = kcalloc(priv->rx_ring_size, sizeof(void *), GFP_KERNEL); - if (!priv->rx_skb) { + if (!priv->rx_buf) { dev_err(kdev, "cannot allocate rx skb queue\n"); ret = -ENOMEM; goto out_free_tx_skb; @@ -2202,7 +2206,7 @@ static int bcm_enetsw_open(struct net_device *dev) enet_dma_writel(priv, ENETDMA_BUFALLOC_FORCE_MASK | 0, ENETDMA_BUFALLOC_REG(priv->rx_chan)); - if (bcm_enet_refill_rx(dev)) { + if (bcm_enet_refill_rx(dev, false)) { dev_err(kdev, "cannot allocate rx skb queue\n"); ret = -ENOMEM; goto out; @@ -2303,18 +2307,7 @@ static int bcm_enetsw_open(struct net_device *dev) return 0; out: - for (i = 0; i < priv->rx_ring_size; i++) { - struct bcm_enet_desc *desc; - - if (!priv->rx_skb[i]) - continue; - - desc = &priv->rx_desc_cpu[i]; - dma_unmap_single(kdev, desc->address, priv->rx_skb_size, - DMA_FROM_DEVICE); - kfree_skb(priv->rx_skb[i]); - } - kfree(priv->rx_skb); + bcm_enet_free_rx_buf_ring(kdev, priv); out_free_tx_skb: kfree(priv->tx_skb); @@ -2343,7 +2336,6 @@ static int bcm_enetsw_stop(struct net_device *dev) { struct bcm_enet_priv *priv; struct device *kdev; - int i; priv = netdev_priv(dev); kdev = &priv->pdev->dev; @@ -2364,21 +2356,10 @@ static int bcm_enetsw_stop(struct net_device *dev) /* force reclaim of all tx buffers */ bcm_enet_tx_reclaim(dev, 1); - /* free the rx skb ring */ - for (i = 0; i < priv->rx_ring_size; i++) { - struct bcm_enet_desc *desc; - - if (!priv->rx_skb[i]) - continue; - - desc = &priv->rx_desc_cpu[i]; - dma_unmap_single(kdev, desc->address, priv->rx_skb_size, - DMA_FROM_DEVICE); - kfree_skb(priv->rx_skb[i]); - } + /* free the rx buffer ring */ + bcm_enet_free_rx_buf_ring(kdev, priv); /* free remaining allocated memory */ - kfree(priv->rx_skb); kfree(priv->tx_skb); dma_free_coherent(kdev, priv->rx_desc_alloc_size, priv->rx_desc_cpu, priv->rx_desc_dma); @@ -2675,6 +2656,7 @@ static int bcm_enetsw_probe(struct platform_device *pdev) priv->rx_ring_size = BCMENET_DEF_RX_DESC; priv->tx_ring_size = BCMENET_DEF_TX_DESC; priv->dma_maxburst = BCMENETSW_DMA_MAXBURST; + priv->rx_buf_offset = NET_SKB_PAD + NET_IP_ALIGN; pd = dev_get_platdata(&pdev->dev); if (pd) { diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.h b/drivers/net/ethernet/broadcom/bcm63xx_enet.h index 1d3c917eb830..78f1830fb3cb 100644 --- a/drivers/net/ethernet/broadcom/bcm63xx_enet.h +++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.h @@ -230,11 +230,17 @@ struct bcm_enet_priv { /* next dirty rx descriptor to refill */ int rx_dirty_desc; - /* size of allocated rx skbs */ - unsigned int rx_skb_size; + /* size of allocated rx buffers */ + unsigned int rx_buf_size; - /* list of skb given to hw for rx */ - struct sk_buff **rx_skb; + /* allocated rx buffer offset */ + unsigned int rx_buf_offset; + + /* size of allocated rx frag */ + unsigned int rx_frag_size; + + /* list of buffer given to hw for rx */ + void **rx_buf; /* used when rx skb allocation failed, so we defer rx queue * refill */