From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3E531CD343F for ; Sat, 9 May 2026 13:06:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To:In-Reply-To:References :Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=a4qqVuY20vWi5Wyys0RJEI/xkcBg3JMmfkSa061S4Sk=; b=I72RjvbQCQqRQRQJ/QnDMbbYOb 1XoVsiCbDXC0a6kumfu6lfb2Fu8yvnCqV2tOzhQveip+tIPmNGnppp+WtZ/eK/T1d9DAr6Omj6FSA gMVuDI7UQtAQTqkYS3A83q8cSRYxyhkjgs4uUq7u6cqR2Q4oBVfbENpYUKvzQEn31SPdPK/oB55wF nq64MvU/NtfVAsxI1+J3ScXKH5ZfuXX+UCjd7tpYpR6Cs7Lb7NpEuN3tOqGW6Z0yeCS1M98iCmun1 ipCnoDb3wxav0S9da7xjoeWurGfaTWGR1f+8WzQBJp/vMeL1vo7p8Jb/+mcfj8kApuhZJckOWegI8 EBFupvNQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wLhNb-00000008yLC-0nYx; Sat, 09 May 2026 13:06:03 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wLhNX-00000008yHt-2LQ6; Sat, 09 May 2026 13:06:00 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 1FF4F43C56; Sat, 9 May 2026 13:05:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3475C2BCB2; Sat, 9 May 2026 13:05:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778331959; bh=i/o5rMhIgPyVu8XYuoQS4qdrmGAHMa4Oy5hB1iaTjr8=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=KPoxKkdr9UB9t1A2L3eKyMymC9McgcC94weQafa6PnZhoHGo6l/bh0AS+MmwG5ZaH RaVf4BlHxX3N8ns+5rvrfa0EMh9PbXGOOiN6IdOb8URZd3tCxedFY8vNLS1IBXn9oD mOd1UI59l6z5WxgF31r5GXkGp9jPhODlMwXiuAgZSLMtkdxgQqvxF5tzHxZi/W6YAI Grwu/5KX7ndbnYSuS5j3zadmzIT5T/Lk2DH6Nc2RwJq12nfiObBNN3FHVjKln2RNM2 /HZHVNApFZd+3hMyak8An06F/kPeBDpUPth5NLLXRiGUr9xXx1AzCwBKQMdjuHgoei 1OlrEEUXgURxg== From: Lorenzo Bianconi Date: Sat, 09 May 2026 15:05:27 +0200 Subject: [PATCH net-next v5 02/12] net: airoha: Reserve RX headroom to avoid skb reallocation MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260509-airoha-eth-multi-serdes-v5-2-805e38edc2aa@kernel.org> References: <20260509-airoha-eth-multi-serdes-v5-0-805e38edc2aa@kernel.org> In-Reply-To: <20260509-airoha-eth-multi-serdes-v5-0-805e38edc2aa@kernel.org> To: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Lorenzo Bianconi Cc: Christian Marangi , Benjamin Larsson , linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, Xuegang Lu X-Mailer: b4 0.14.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260509_060559_782386_E3E43393 X-CRM114-Status: GOOD ( 11.18 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org Reserve NET_SKB_PAD + NET_IP_ALIGN bytes of headroom for received packets to avoid skb head reallocation when pushing protocol headers into the skb. Tested-by: Xuegang Lu Signed-off-by: Lorenzo Bianconi --- drivers/net/ethernet/airoha/airoha_eth.c | 8 ++++++-- drivers/net/ethernet/airoha/airoha_eth.h | 1 + 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c index f71fb18197ec..8a941c58d1b4 100644 --- a/drivers/net/ethernet/airoha/airoha_eth.c +++ b/drivers/net/ethernet/airoha/airoha_eth.c @@ -543,9 +543,11 @@ static int airoha_qdma_fill_rx_queue(struct airoha_queue *q) q->queued++; nframes++; + offset += AIROHA_RX_HEADROOM; e->buf = page_address(page) + offset; e->dma_addr = page_pool_get_dma_addr(page) + offset; - e->dma_len = SKB_WITH_OVERHEAD(q->buf_size); + e->dma_len = SKB_WITH_OVERHEAD(q->buf_size - + AIROHA_RX_HEADROOM); val = FIELD_PREP(QDMA_DESC_LEN_MASK, e->dma_len); WRITE_ONCE(desc->ctrl, cpu_to_le32(val)); @@ -627,10 +629,12 @@ static int airoha_qdma_rx_process(struct airoha_queue *q, int budget) port = eth->ports[p]; if (!q->skb) { /* first buffer */ - q->skb = napi_build_skb(e->buf, q->buf_size); + q->skb = napi_build_skb(e->buf - AIROHA_RX_HEADROOM, + q->buf_size); if (!q->skb) goto free_frag; + skb_reserve(q->skb, AIROHA_RX_HEADROOM); __skb_put(q->skb, len); skb_mark_for_recycle(q->skb); q->skb->dev = port->dev; diff --git a/drivers/net/ethernet/airoha/airoha_eth.h b/drivers/net/ethernet/airoha/airoha_eth.h index 58530d096de7..6cd589b790b6 100644 --- a/drivers/net/ethernet/airoha/airoha_eth.h +++ b/drivers/net/ethernet/airoha/airoha_eth.h @@ -32,6 +32,7 @@ #define AIROHA_FE_MC_MAX_VLAN_TABLE 64 #define AIROHA_FE_MC_MAX_VLAN_PORT 16 #define AIROHA_NUM_TX_IRQ 2 +#define AIROHA_RX_HEADROOM (NET_SKB_PAD + NET_IP_ALIGN) #define HW_DSCP_NUM 2048 #define IRQ_QUEUE_LEN(_n) ((_n) ? 1024 : 2048) #define TX_DSCP_NUM 1024 -- 2.54.0