From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.tipi-net.de (mail.tipi-net.de [194.13.80.246]) (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 8C92A1C84C0; Fri, 13 Mar 2026 09:21:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.13.80.246 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773393691; cv=none; b=WkA2PUclKLbpbaGOrt72thdWbkq9VIz6HO0IQIpUdbcwf1fZUSXveJ+RYhAFaJTgxrZsvaPKqSCdMznk0G6WbmUTuTh38pMNx7IW1+S++3AfmACLSg9kTKux4gcrp9aGbm7yEjbpKuq8oYCBbRvvm52rNZvSPL730nsAHLX+s7k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773393691; c=relaxed/simple; bh=NvfHN+YwB5Uh1b17ClXrK/yAJiY1ImX9zrosgTCVRM4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JoNOI8Iv0zO79sFrIfY23D0cY2/FwOlI9lnMeaXsdFlR8dRiQmm4WI3kzOSUHin6MbF0nQ+sELjtdoO8Sg/VR05M8N2P4R49mR2rqesJkP+iBwpqxNwKFxdMOPwtxAVCbPzMr32fXx/JaZWnpd9GJ0Q2/iayXxKg6aVEzlRyv78= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tipi-net.de; spf=pass smtp.mailfrom=tipi-net.de; dkim=pass (2048-bit key) header.d=tipi-net.de header.i=@tipi-net.de header.b=fv9patpJ; arc=none smtp.client-ip=194.13.80.246 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tipi-net.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tipi-net.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=tipi-net.de header.i=@tipi-net.de header.b="fv9patpJ" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 7DBCFA5705; Fri, 13 Mar 2026 10:21:21 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tipi-net.de; s=dkim; t=1773393682; h=from:subject:date:message-id:to:cc:mime-version: content-transfer-encoding:in-reply-to:references; bh=JlNTVCCEMpLe+QdV6Hc3TyF9BpdyJ2SM/Cy6iXmvFjA=; b=fv9patpJsg3eCa8jIZIvcWWwRH87qJRg3cCD0ytJlVuhF36FQKuZ8qMFbHexYkdROTEZ7Y DRu6q2MB9lJ8Ua7JRKxJtDfq6kTuIZqFF7JPwrHU7uqFCCTyxI+9MDm81FiBt2TrsD4Vtb ei25C7+LAqdDDY0jVdhErEaUgqW/+2vbJ36nRlJ0cDfiERZE1EnaIZcrfap5AdAGRkHay5 7TTl0oOQJScFCOanuOOu7vzm5+qn0uHNWci5jGm0azzCMeG6ns8pxOrmE5Qf3iry2qGP6A z+jxVrvEDZdz1t95DSVHVhm1qSZ1L+tZPmfHKq2VZrGW11oTT2VPhhdKxRkdCg== From: Nicolai Buchwitz To: Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Doug Berger , Florian Fainelli Cc: Broadcom internal kernel review list , Vikas Gupta , Bhargava Marreddy , Rajashekar Hudumula , Eric Biggers , Heiner Kallweit , =?UTF-8?q?Markus=20Bl=C3=B6chl?= , Arnd Bergmann , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Nicolai Buchwitz Subject: [PATCH net-next 4/6] net: bcmgenet: add XDP_TX support Date: Fri, 13 Mar 2026 10:20:59 +0100 Message-ID: <20260313092101.1344954-5-nb@tipi-net.de> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260313092101.1344954-1-nb@tipi-net.de> References: <20260313092101.1344954-1-nb@tipi-net.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 Implement XDP_TX by submitting XDP frames through the default TX ring (DESC_INDEX). The frame is DMA-mapped and placed into a single TX descriptor with SOP|EOP|APPEND_CRC flags. The xdp_frame pointer is stored in the TX control block so that bcmgenet_free_tx_cb() can call xdp_return_frame() on TX completion, returning the page to the originating page_pool. The page_pool DMA direction is changed from DMA_FROM_DEVICE to DMA_BIDIRECTIONAL to support the TX DMA mapping of received pages. Signed-off-by: Nicolai Buchwitz --- .../net/ethernet/broadcom/genet/bcmgenet.c | 73 ++++++++++++++++++- .../net/ethernet/broadcom/genet/bcmgenet.h | 1 + 2 files changed, 71 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c index d43729fc2b1b..373ba5878ca1 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c @@ -1893,6 +1893,12 @@ static struct sk_buff *bcmgenet_free_tx_cb(struct device *dev, if (cb == GENET_CB(skb)->last_cb) return skb; + } else if (cb->xdpf) { + dma_unmap_single(dev, dma_unmap_addr(cb, dma_addr), + dma_unmap_len(cb, dma_len), DMA_TO_DEVICE); + dma_unmap_addr_set(cb, dma_addr, 0); + xdp_return_frame(cb->xdpf); + cb->xdpf = NULL; } else if (dma_unmap_addr(cb, dma_addr)) { dma_unmap_page(dev, dma_unmap_addr(cb, dma_addr), @@ -2299,10 +2305,62 @@ static struct sk_buff *bcmgenet_xdp_build_skb(struct bcmgenet_rx_ring *ring, return skb; } +static bool bcmgenet_xdp_xmit_frame(struct bcmgenet_priv *priv, + struct xdp_frame *xdpf) +{ + struct bcmgenet_tx_ring *ring = &priv->tx_rings[DESC_INDEX]; + struct device *kdev = &priv->pdev->dev; + struct enet_cb *tx_cb_ptr; + dma_addr_t mapping; + u32 len_stat; + + spin_lock(&ring->lock); + + if (ring->free_bds < 1) { + spin_unlock(&ring->lock); + return false; + } + + tx_cb_ptr = bcmgenet_get_txcb(priv, ring); + + mapping = dma_map_single(kdev, xdpf->data, xdpf->len, DMA_TO_DEVICE); + if (dma_mapping_error(kdev, mapping)) { + tx_cb_ptr->skb = NULL; + tx_cb_ptr->xdpf = NULL; + bcmgenet_put_txcb(priv, ring); + spin_unlock(&ring->lock); + return false; + } + + dma_unmap_addr_set(tx_cb_ptr, dma_addr, mapping); + dma_unmap_len_set(tx_cb_ptr, dma_len, xdpf->len); + tx_cb_ptr->skb = NULL; + tx_cb_ptr->xdpf = xdpf; + + len_stat = (xdpf->len << DMA_BUFLENGTH_SHIFT) | + (priv->hw_params->qtag_mask << DMA_TX_QTAG_SHIFT) | + DMA_TX_APPEND_CRC | DMA_SOP | DMA_EOP; + + dmadesc_set(priv, tx_cb_ptr->bd_addr, mapping, len_stat); + + ring->free_bds--; + ring->prod_index++; + ring->prod_index &= DMA_P_INDEX_MASK; + + bcmgenet_tdma_ring_writel(priv, ring->index, ring->prod_index, + TDMA_PROD_INDEX); + + spin_unlock(&ring->lock); + + return true; +} + static unsigned int bcmgenet_run_xdp(struct bcmgenet_rx_ring *ring, struct bpf_prog *prog, struct xdp_buff *xdp, struct page *rx_page) { + struct bcmgenet_priv *priv = ring->priv; + struct xdp_frame *xdpf; unsigned int act; act = bpf_prog_run_xdp(prog, xdp); @@ -2310,14 +2368,23 @@ bcmgenet_run_xdp(struct bcmgenet_rx_ring *ring, struct bpf_prog *prog, switch (act) { case XDP_PASS: return XDP_PASS; + case XDP_TX: + xdpf = xdp_convert_buff_to_frame(xdp); + if (unlikely(!xdpf) || + unlikely(!bcmgenet_xdp_xmit_frame(priv, xdpf))) { + page_pool_put_full_page(ring->page_pool, rx_page, + true); + return XDP_DROP; + } + return XDP_TX; case XDP_DROP: page_pool_put_full_page(ring->page_pool, rx_page, true); return XDP_DROP; default: - bpf_warn_invalid_xdp_action(ring->priv->dev, prog, act); + bpf_warn_invalid_xdp_action(priv->dev, prog, act); fallthrough; case XDP_ABORTED: - trace_xdp_exception(ring->priv->dev, prog, act); + trace_xdp_exception(priv->dev, prog, act); page_pool_put_full_page(ring->page_pool, rx_page, true); return XDP_ABORTED; } @@ -2846,7 +2913,7 @@ static int bcmgenet_rx_ring_create_pool(struct bcmgenet_priv *priv, .pool_size = ring->size, .nid = NUMA_NO_NODE, .dev = &priv->pdev->dev, - .dma_dir = DMA_FROM_DEVICE, + .dma_dir = DMA_BIDIRECTIONAL, .offset = GENET_XDP_HEADROOM, .max_len = RX_BUF_LENGTH, }; diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h index 1459473ac1b0..192db0defbfc 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h @@ -472,6 +472,7 @@ struct bcmgenet_rx_stats64 { struct enet_cb { struct sk_buff *skb; + struct xdp_frame *xdpf; struct page *rx_page; unsigned int rx_page_offset; void __iomem *bd_addr; -- 2.51.0