From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AC8F52DF9A for ; Tue, 7 Nov 2023 12:11:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="B/Ai+Qlo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 07C02C433CC; Tue, 7 Nov 2023 12:11:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699359077; bh=Aw+WavNJEFyQoSXX2QTBy/2kyLsJIMXF0GP9NDVNU5o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B/Ai+QlolRlS5dHc+R7gCo1jhZxAgaPgIGabk+vBpeI2zktyBDIoKFvJKkMRNnmdk GjugobF+C5GB3wSQUtc7HcU7EyohYjrVE1O2kc1C7L6BcqWGibgUenou6G3Va+L+tv Lw0tHgROtQmFgR73usL5muO9+UyUfH8DFlKsx3O1+BI9ab/kbQZuGfRwF9+jsNa86O dwm8ZQYJ7qygXjjYG3V8BC2ienEID3HEKMbn11I7YnJpwHFHVA1AJfOoSpgj6fMuSY avm71OaMcUMnEZ+OcGl6ATEMeE2lRQbsabambxooGY4Py9/XIfUN3u5J2+SHO3UxkM +rQ2Ul0ge3a0A== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sieng-Piaw Liew , Paolo Abeni , Sasha Levin , chris.snook@gmail.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, horms@kernel.org, pavan.chebbi@broadcom.com, ruc_gongyuanjun@163.com, trix@redhat.com, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 6.1 04/18] atl1c: Work around the DMA RX overflow issue Date: Tue, 7 Nov 2023 07:10:34 -0500 Message-ID: <20231107121104.3757943-4-sashal@kernel.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231107121104.3757943-1-sashal@kernel.org> References: <20231107121104.3757943-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.61 Content-Transfer-Encoding: 8bit From: Sieng-Piaw Liew [ Upstream commit 86565682e9053e5deb128193ea9e88531bbae9cf ] This is based on alx driver commit 881d0327db37 ("net: alx: Work around the DMA RX overflow issue"). The alx and atl1c drivers had RX overflow error which was why a custom allocator was created to avoid certain addresses. The simpler workaround then created for alx driver, but not for atl1c due to lack of tester. Instead of using a custom allocator, check the allocated skb address and use skb_reserve() to move away from problematic 0x...fc0 address. Tested on AR8131 on Acer 4540. Signed-off-by: Sieng-Piaw Liew Link: https://lore.kernel.org/r/20230912010711.12036-1-liew.s.piaw@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/ethernet/atheros/atl1c/atl1c.h | 3 - .../net/ethernet/atheros/atl1c/atl1c_main.c | 67 +++++-------------- 2 files changed, 16 insertions(+), 54 deletions(-) diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c.h b/drivers/net/ethernet/atheros/atl1c/atl1c.h index 43d821fe7a542..63ba64dbb7310 100644 --- a/drivers/net/ethernet/atheros/atl1c/atl1c.h +++ b/drivers/net/ethernet/atheros/atl1c/atl1c.h @@ -504,15 +504,12 @@ struct atl1c_rrd_ring { u16 next_to_use; u16 next_to_clean; struct napi_struct napi; - struct page *rx_page; - unsigned int rx_page_offset; }; /* board specific private data structure */ struct atl1c_adapter { struct net_device *netdev; struct pci_dev *pdev; - unsigned int rx_frag_size; struct atl1c_hw hw; struct atl1c_hw_stats hw_stats; struct mii_if_info mii; /* MII interface info */ diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c index 7762e532c6a4f..6eb86d75955fe 100644 --- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c +++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c @@ -493,15 +493,10 @@ static int atl1c_set_mac_addr(struct net_device *netdev, void *p) static void atl1c_set_rxbufsize(struct atl1c_adapter *adapter, struct net_device *dev) { - unsigned int head_size; int mtu = dev->mtu; adapter->rx_buffer_len = mtu > AT_RX_BUF_SIZE ? roundup(mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN, 8) : AT_RX_BUF_SIZE; - - head_size = SKB_DATA_ALIGN(adapter->rx_buffer_len + NET_SKB_PAD + NET_IP_ALIGN) + - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - adapter->rx_frag_size = roundup_pow_of_two(head_size); } static netdev_features_t atl1c_fix_features(struct net_device *netdev, @@ -974,7 +969,6 @@ static void atl1c_init_ring_ptrs(struct atl1c_adapter *adapter) static void atl1c_free_ring_resources(struct atl1c_adapter *adapter) { struct pci_dev *pdev = adapter->pdev; - int i; dma_free_coherent(&pdev->dev, adapter->ring_header.size, adapter->ring_header.desc, adapter->ring_header.dma); @@ -987,12 +981,6 @@ static void atl1c_free_ring_resources(struct atl1c_adapter *adapter) kfree(adapter->tpd_ring[0].buffer_info); adapter->tpd_ring[0].buffer_info = NULL; } - for (i = 0; i < adapter->rx_queue_count; ++i) { - if (adapter->rrd_ring[i].rx_page) { - put_page(adapter->rrd_ring[i].rx_page); - adapter->rrd_ring[i].rx_page = NULL; - } - } } /** @@ -1764,48 +1752,11 @@ static inline void atl1c_rx_checksum(struct atl1c_adapter *adapter, skb_checksum_none_assert(skb); } -static struct sk_buff *atl1c_alloc_skb(struct atl1c_adapter *adapter, - u32 queue, bool napi_mode) -{ - struct atl1c_rrd_ring *rrd_ring = &adapter->rrd_ring[queue]; - struct sk_buff *skb; - struct page *page; - - if (adapter->rx_frag_size > PAGE_SIZE) { - if (likely(napi_mode)) - return napi_alloc_skb(&rrd_ring->napi, - adapter->rx_buffer_len); - else - return netdev_alloc_skb_ip_align(adapter->netdev, - adapter->rx_buffer_len); - } - - page = rrd_ring->rx_page; - if (!page) { - page = alloc_page(GFP_ATOMIC); - if (unlikely(!page)) - return NULL; - rrd_ring->rx_page = page; - rrd_ring->rx_page_offset = 0; - } - - skb = build_skb(page_address(page) + rrd_ring->rx_page_offset, - adapter->rx_frag_size); - if (likely(skb)) { - skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN); - rrd_ring->rx_page_offset += adapter->rx_frag_size; - if (rrd_ring->rx_page_offset >= PAGE_SIZE) - rrd_ring->rx_page = NULL; - else - get_page(page); - } - return skb; -} - static int atl1c_alloc_rx_buffer(struct atl1c_adapter *adapter, u32 queue, bool napi_mode) { struct atl1c_rfd_ring *rfd_ring = &adapter->rfd_ring[queue]; + struct atl1c_rrd_ring *rrd_ring = &adapter->rrd_ring[queue]; struct pci_dev *pdev = adapter->pdev; struct atl1c_buffer *buffer_info, *next_info; struct sk_buff *skb; @@ -1824,13 +1775,27 @@ static int atl1c_alloc_rx_buffer(struct atl1c_adapter *adapter, u32 queue, while (next_info->flags & ATL1C_BUFFER_FREE) { rfd_desc = ATL1C_RFD_DESC(rfd_ring, rfd_next_to_use); - skb = atl1c_alloc_skb(adapter, queue, napi_mode); + /* When DMA RX address is set to something like + * 0x....fc0, it will be very likely to cause DMA + * RFD overflow issue. + * + * To work around it, we apply rx skb with 64 bytes + * longer space, and offset the address whenever + * 0x....fc0 is detected. + */ + if (likely(napi_mode)) + skb = napi_alloc_skb(&rrd_ring->napi, adapter->rx_buffer_len + 64); + else + skb = netdev_alloc_skb(adapter->netdev, adapter->rx_buffer_len + 64); if (unlikely(!skb)) { if (netif_msg_rx_err(adapter)) dev_warn(&pdev->dev, "alloc rx buffer failed\n"); break; } + if (((unsigned long)skb->data & 0xfff) == 0xfc0) + skb_reserve(skb, 64); + /* * Make buffer alignment 2 beyond a 16 byte boundary * this will result in a 16 byte aligned IP header after -- 2.42.0