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 854313BB9F8; Mon, 11 May 2026 10:49:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778496596; cv=none; b=rPyjZxpPBHHYLPrBxlNWMmsEcKal05uWumUJJnJH4jNrsRfkNCwkb/yk1LqVu2WORuEppYGUxeYjS0kq9J6XaOaB9j5XyEKvt+igehK7j2YmBNoedEAXrv3iSbtGF71P8IJSGoZTsH/Gbx31Za1jxexoVvxLMan7ZxQBqjiyhr8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778496596; c=relaxed/simple; bh=GtTOCUnQPmRi1bdY3r2oyNNR2Jf+SjIm6GiVXh4YsaU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=H7G/w9TMLGTbXccNTZtfKNtUo1Gn8rNFrfFzlY3dbrTsPL2cMmgr5zgZR/Id297vt0AcWsOXesE7X9oJsXoaRo4SDjCvsF+WZRF2zwTIuS+Bz42mL9Kk9k2rA5o3MsYhdrjhT/D+GWiJFLAQg3W/YGFPc4froTPkJ/t31ivSClM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GSms5RNq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GSms5RNq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13554C2BCFA; Mon, 11 May 2026 10:49:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778496596; bh=GtTOCUnQPmRi1bdY3r2oyNNR2Jf+SjIm6GiVXh4YsaU=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=GSms5RNqkNhlpdXvq5TB2KG/fRLLNTupXApZr7dBsn1q7uP9iL1tz+MyEi0HhYcht RsxfTgcMf0DvAci4ILETh/P/LsaroXhEZlEkX+r4jxgSjdJLBenCx/kmBt8wQ3Oy6I uQ7oCgBNmNTRBjn1A4HxRGoRa3yRv28Dms5hiDbxSd5XzG9mLw+F2dSV8mYmKXEyP/ pDlyLvwqmi6fn2M0ggQjC3t9xNhe6Tz7YtU1/xgPMUL8NUglyxfAOcKzutOZbyIpKs KY+c8GBOoPVBJING2Pgbydf9/Zt6ajG4qaho41j9fFtuDIpkhQO20K+0FTot1emASo lprq6K+vknpKg== From: Lorenzo Bianconi Date: Mon, 11 May 2026 12:49:28 +0200 Subject: [PATCH net-next v6 02/12] net: airoha: Reserve RX headroom to avoid skb reallocation Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260511-airoha-eth-multi-serdes-v6-2-c899462c4f75@kernel.org> References: <20260511-airoha-eth-multi-serdes-v6-0-c899462c4f75@kernel.org> In-Reply-To: <20260511-airoha-eth-multi-serdes-v6-0-c899462c4f75@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 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 | 12 ++++++++---- drivers/net/ethernet/airoha/airoha_eth.h | 2 ++ 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c index f71fb18197ec..3fe2561c85f1 100644 --- a/drivers/net/ethernet/airoha/airoha_eth.c +++ b/drivers/net/ethernet/airoha/airoha_eth.c @@ -543,9 +543,10 @@ 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(AIROHA_RX_LEN(q->buf_size)); val = FIELD_PREP(QDMA_DESC_LEN_MASK, e->dma_len); WRITE_ONCE(desc->ctrl, cpu_to_le32(val)); @@ -616,8 +617,9 @@ static int airoha_qdma_rx_process(struct airoha_queue *q, int budget) page = virt_to_head_page(e->buf); len = FIELD_GET(QDMA_DESC_LEN_MASK, desc_ctrl); - data_len = q->skb ? q->buf_size - : SKB_WITH_OVERHEAD(q->buf_size); + data_len = q->skb + ? AIROHA_RX_LEN(q->buf_size) + : SKB_WITH_OVERHEAD(AIROHA_RX_LEN(q->buf_size)); if (!len || data_len < len) goto free_frag; @@ -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..d3781103abb5 100644 --- a/drivers/net/ethernet/airoha/airoha_eth.h +++ b/drivers/net/ethernet/airoha/airoha_eth.h @@ -32,6 +32,8 @@ #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 AIROHA_RX_LEN(_n) ((_n) - AIROHA_RX_HEADROOM) #define HW_DSCP_NUM 2048 #define IRQ_QUEUE_LEN(_n) ((_n) ? 1024 : 2048) #define TX_DSCP_NUM 1024 -- 2.54.0