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 4BEAACD4851 for ; Wed, 13 May 2026 15:04:22 +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: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:In-Reply-To:References:List-Owner; bh=nObldBkoFz93TvD+rJyqHcpBLDBEZ04xwgIHNgsnAO8=; b=2PTrGdJ9dGQ92or0cmwB+BrqQb CWzr7oQLrZE6DlMK4lU/l41S6GdDsZ3JYhcwl63syjmR/6Oe6qYpJh1hl7kA4eMKeettJa3jDNqsb cL7QMBvKi7yowbJum5vuxWZPTQArH6kiG0ghFjd6dhZu6w3DZpyjorWp9l+TItzImBbHm8NSSM3QL xaEIJXhucrK6A0vli8Hp10JC+m99tzJsGD45nHw+43FjtEUVDF/JKzkiY963HSHeIjr8hP8XL0suQ QHrNWC1vdOtHQ2jOxWGXTfd7X+ghz1wnH3DgXTL8+jGM7d6Rdk8U8fv6aLbDYVyj6btKjFmmA8/4m uXxKKwpg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wNB8B-0000000316S-0GdS; Wed, 13 May 2026 15:04:15 +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 1wNB87-0000000315o-3h5O; Wed, 13 May 2026 15:04:12 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 2854543DB5; Wed, 13 May 2026 15:04:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEDDBC19425; Wed, 13 May 2026 15:04:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778684651; bh=iliNH01E0zCiR4ewRpQV15XeBpC7YO/HdMRcKK4W6Pc=; h=From:Date:Subject:To:Cc:From; b=bjBDGjnbHvLYaOEiG9nuqJk7YEMQb2VQpKoPHXjdQXblqZcdm561Qe/3MuOtCDaZd FKzh1KCl0FBkts3VT4Ks6sJnnoKYOe3ByrO5mKx83nfoN9tTZOgSqXS9CE9B/n3luX Qb4lv/pVLkbf8crrPPNsUQnFnvwJlhUodzxSqAj7l6L+VM+s0O2wjqn2E2Bx7XtZut uikhh8u5QNKm9F00CxrprCmzOSoon4Wu8vkvafONK2ukxs3StgVssSdLXYasSisvpl K9Fj1rBSe2VxTBm36tKU+Dqei+6/lRU5bEbPFlQNPZOqyrFPSKKQYCY+RtTd70IbM7 70tS4jddPVnLQ== From: Lorenzo Bianconi Date: Wed, 13 May 2026 17:03:59 +0200 Subject: [PATCH net-next] 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: <20260513-airoha-rx-headroom-v1-1-bd87798e422d@kernel.org> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/x3MQQqEMAxA0atI1hNonSp1rjLMIthos7AdUpGCe HeLy7f4/4TCKlzg052gfEiRnBrsq4M5UloZJTRDb/rRDPaNJJojoVaMTEFz3tAFO83knSfroIV /5UXqM/1C4h0T1x1+13UDkkWbjm4AAAA= X-Change-ID: 20260513-airoha-rx-headroom-4d19ca848a14 To: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Lorenzo Bianconi Cc: linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, netdev@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-20260513_080411_965678_20AE910F X-CRM114-Status: UNSURE ( 9.92 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=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 | 14 ++++++++------ drivers/net/ethernet/airoha/airoha_eth.h | 2 ++ 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c index f71fb18197ec..5a027cc7ffcb 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)); @@ -611,13 +612,12 @@ static int airoha_qdma_rx_process(struct airoha_queue *q, int budget) q->tail = (q->tail + 1) % q->ndesc; q->queued--; - dma_sync_single_for_cpu(eth->dev, e->dma_addr, - SKB_WITH_OVERHEAD(q->buf_size), dir); + dma_sync_single_for_cpu(eth->dev, e->dma_addr, e->dma_len, + dir); 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) : e->dma_len; if (!len || data_len < len) goto free_frag; @@ -627,10 +627,12 @@ 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 --- base-commit: 8ebd24a7822cbae25beeafba49b2159d6a68a5f2 change-id: 20260513-airoha-rx-headroom-4d19ca848a14 Best regards, -- Lorenzo Bianconi