From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.154.123]) (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 CFAB84E9C20; Fri, 18 Sep 2026 11:34:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=68.232.154.123 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789731278; cv=none; b=n8qiRo49bobueluwm3kzXrfo/8FN5OsCLJ9h7yb15qapyfV0QwGIK5+2bhBSjCfic5/JDvcGkx31kaSvZVQimnGkyIp1AYayjDhOO5cmp0WoIbkiia0OBiIYC3Ln35DmqMnBP+IjrZLbUtlRceZUVbjPUz89bjZQeTmnKANKX7c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789731278; c=relaxed/simple; bh=zBov56ra9TQQ0Btxz615KJ63MNaEZMJU8uYgTEPF1Xs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:References: In-Reply-To:To:CC; b=OS7XuOaU+22P84aHbrFUyKIIRACzOAITlIwG7qu8mpR+hTNR1U1D/vNXWWGvxSNzcPdPBENxMu7vqI7xqO9DYTe79UfGJMbRUhUkFO62Zrkny6tMmsrFgul44BMzcBFSNaXNo1S4Cerv37FmsDYZp3ILoDofP3/4JYve3DXN3M8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=microchip.com; spf=pass smtp.mailfrom=microchip.com; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b=tAf+mY8P; arc=none smtp.client-ip=68.232.154.123 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=microchip.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=microchip.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b="tAf+mY8P" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1789731276; x=1821267276; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=zBov56ra9TQQ0Btxz615KJ63MNaEZMJU8uYgTEPF1Xs=; b=tAf+mY8PKNyGoB90juOq4QrTU8cFhgHjgavA/FoTEnYg6ee6w1Yzw2hU 725Inl4TSVBUQQjrIajL/IMDvXbKESkGsAjVf9qwqc4a6L0PzwYXII3V0 PJbqtdKRl5ugMbJd4QL5mFSbDsvz+E/JHSSmrWSsQ+fXysbVMv3jvErpQ IqhnnFQqzM6hvs993XFrPcrNnwJrMkScUsX6QJtJ5OE6MtCkPt3haKemi Ti3vagthaOeiY0aMXF2f7OhaOvudCRwp+qOrcH0py7aN4Nl7MbKgXB9xP HOQQQy66L0XhBYdiTHskLUaMFJQjs913x01MO4C5oAqpbK+4d/PXJQdbL w==; X-CSE-ConnectionGUID: o9fjoqvGQQqHiQsTpI+I6A== X-CSE-MsgGUID: gWeiHw1GTquzLcJGob9g1w== X-IronPort-AV: E=Sophos;i="6.27,108,1787036400"; d="scan'208";a="62877999" X-Amp-Result: SKIPPED(no attachment in message) Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa4.microchip.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 18 Sep 2026 04:34:35 -0700 Received: from chn-vm-ex04.mchp-main.com (10.10.85.152) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.58; Fri, 18 Sep 2026 04:34:35 -0700 Received: from DEN-DL-M70577.microsemi.net (10.10.85.11) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server id 15.1.2507.58 via Frontend Transport; Fri, 18 Sep 2026 04:34:31 -0700 From: Daniel Machon Date: Fri, 18 Sep 2026 13:33:58 +0200 Subject: [PATCH net-next v7 06/14] net: lan966x: use a dedicated device for DMA operations 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: <20260918-lan966x-pci-fdma-v7-6-0ecc179c8a2c@microchip.com> References: <20260918-lan966x-pci-fdma-v7-0-0ecc179c8a2c@microchip.com> In-Reply-To: <20260918-lan966x-pci-fdma-v7-0-0ecc179c8a2c@microchip.com> To: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Horatiu Vultur , Steen Hegelund , , "Alexei Starovoitov" , Daniel Borkmann , "Jesper Dangaard Brouer" , John Fastabend , Stanislav Fomichev , Herve Codina , Arnd Bergmann , Greg Kroah-Hartman , Mohsin Bashir CC: Richard Cochran , , , , X-Mailer: b4 0.14.3 In preparation for the PCIe FDMA implementation, add lan966x->dma_dev, resolved once at probe time, and use it for every DMA operation the FDMA path performs: coherent allocations, streaming mappings and the RX page pool. Natively, dma_dev is lan966x->dev, so there is no functional change. Since dma_dev differs from dev only on the PCIe path, add lan966x_is_pci() on top of it, for the later PCIe patches to key off. Signed-off-by: Daniel Machon --- .../net/ethernet/microchip/lan966x/lan966x_fdma.c | 30 +++++++++++----------- .../net/ethernet/microchip/lan966x/lan966x_main.c | 16 ++++++++++++ .../net/ethernet/microchip/lan966x/lan966x_main.h | 10 ++++++++ 3 files changed, 41 insertions(+), 15 deletions(-) diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c index 1311b79bd11f..15fc59cb4ad7 100644 --- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c @@ -80,7 +80,7 @@ static int lan966x_fdma_rx_alloc_page_pool(struct lan966x_rx *rx) .flags = PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV, .pool_size = rx->fdma.n_dcbs, .nid = NUMA_NO_NODE, - .dev = lan966x->dev, + .dev = lan966x->dma_dev, .dma_dir = DMA_FROM_DEVICE, .offset = XDP_PACKET_HEADROOM, .max_len = rx->max_mtu - @@ -126,7 +126,7 @@ static int lan966x_fdma_rx_alloc(struct lan966x_rx *rx) if (err) return err; - err = fdma_alloc_coherent(lan966x->dev, fdma); + err = fdma_alloc_coherent(lan966x->dma_dev, fdma); if (err) { page_pool_destroy(rx->page_pool); return err; @@ -210,7 +210,7 @@ static int lan966x_fdma_tx_alloc(struct lan966x_tx *tx) if (!tx->dcbs_buf) return -ENOMEM; - err = fdma_alloc_coherent(lan966x->dev, fdma); + err = fdma_alloc_coherent(lan966x->dma_dev, fdma); if (err) goto out; @@ -230,7 +230,7 @@ static void lan966x_fdma_tx_free(struct lan966x_tx *tx) struct lan966x *lan966x = tx->lan966x; kfree(tx->dcbs_buf); - fdma_free_coherent(lan966x->dev, &tx->fdma); + fdma_free_coherent(lan966x->dma_dev, &tx->fdma); } static void lan966x_fdma_tx_activate(struct lan966x_tx *tx) @@ -355,7 +355,7 @@ static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight) dcb_buf->used = false; if (dcb_buf->use_skb) { - dma_unmap_single(lan966x->dev, + dma_unmap_single(lan966x->dma_dev, dcb_buf->dma_addr, dcb_buf->len, DMA_TO_DEVICE); @@ -364,7 +364,7 @@ static void lan966x_fdma_tx_clear_buf(struct lan966x *lan966x, int weight) napi_consume_skb(dcb_buf->data.skb, weight); } else { if (dcb_buf->xdp_ndo) - dma_unmap_single(lan966x->dev, + dma_unmap_single(lan966x->dma_dev, dcb_buf->dma_addr, dcb_buf->len, DMA_TO_DEVICE); @@ -400,7 +400,7 @@ static int lan966x_fdma_rx_check_frame(struct lan966x_rx *rx, u64 *src_port) if (unlikely(!page)) return FDMA_ERROR; - dma_sync_single_for_cpu(lan966x->dev, + dma_sync_single_for_cpu(lan966x->dma_dev, (dma_addr_t)db->dataptr + XDP_PACKET_HEADROOM, FDMA_DCB_STATUS_BLOCKL(db->status), DMA_FROM_DEVICE); @@ -635,11 +635,11 @@ int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, void *ptr, u32 len) lan966x_ifh_set_bypass(ifh, 1); lan966x_ifh_set_port(ifh, BIT_ULL(port->chip_port)); - dma_addr = dma_map_single(lan966x->dev, + dma_addr = dma_map_single(lan966x->dma_dev, xdpf->data - IFH_LEN_BYTES, xdpf->len + IFH_LEN_BYTES, DMA_TO_DEVICE); - if (dma_mapping_error(lan966x->dev, dma_addr)) { + if (dma_mapping_error(lan966x->dma_dev, dma_addr)) { ret = NETDEV_TX_OK; goto out; } @@ -655,7 +655,7 @@ int lan966x_fdma_xmit_xdpf(struct lan966x_port *port, void *ptr, u32 len) lan966x_ifh_set_port(ifh, BIT_ULL(port->chip_port)); dma_addr = page_pool_get_dma_addr(page); - dma_sync_single_for_device(lan966x->dev, + dma_sync_single_for_device(lan966x->dma_dev, dma_addr + XDP_PACKET_HEADROOM, len + IFH_LEN_BYTES, DMA_TO_DEVICE); @@ -734,9 +734,9 @@ int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev) memcpy(skb->data, ifh, IFH_LEN_BYTES); skb_put(skb, 4); - dma_addr = dma_map_single(lan966x->dev, skb->data, skb->len, + dma_addr = dma_map_single(lan966x->dma_dev, skb->data, skb->len, DMA_TO_DEVICE); - if (dma_mapping_error(lan966x->dev, dma_addr)) { + if (dma_mapping_error(lan966x->dma_dev, dma_addr)) { dev->stats.tx_dropped++; err = NETDEV_TX_OK; goto release; @@ -842,7 +842,7 @@ static int lan966x_fdma_reload(struct lan966x *lan966x, int new_mtu) page_pool_put_full_page(page_pool, old_pages[i][j], false); - fdma_free_coherent(lan966x->dev, &fdma_rx_old); + fdma_free_coherent(lan966x->dma_dev, &fdma_rx_old); page_pool_destroy(page_pool); @@ -992,7 +992,7 @@ int lan966x_fdma_init(struct lan966x *lan966x) err = lan966x_fdma_tx_alloc(&lan966x->tx); if (err) { - fdma_free_coherent(lan966x->dev, &lan966x->rx.fdma); + fdma_free_coherent(lan966x->dma_dev, &lan966x->rx.fdma); page_pool_destroy(lan966x->rx.page_pool); return err; } @@ -1014,7 +1014,7 @@ void lan966x_fdma_deinit(struct lan966x *lan966x) napi_disable(&lan966x->napi); lan966x_fdma_rx_free_pages(&lan966x->rx); - fdma_free_coherent(lan966x->dev, &lan966x->rx.fdma); + fdma_free_coherent(lan966x->dma_dev, &lan966x->rx.fdma); page_pool_destroy(lan966x->rx.page_pool); lan966x_fdma_tx_free(&lan966x->tx); } diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c index 1179a6e127c5..2741f7c9fa4c 100644 --- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -1081,6 +1082,20 @@ static int lan966x_reset_switch(struct lan966x *lan966x) return 0; } +/* When enumerated over PCIe, dev is a platform device with no + * iommus/dma-ranges of its own, so DMA must target the PCIe endpoint instead. + * The result differs from dev only in that case; lan966x_is_pci() relies on it. + */ +static struct device *lan966x_get_dma_dev(struct device *dev) +{ + for (struct device *p = dev->parent; p; p = p->parent) { + if (dev_is_pci(p)) + return p; + } + + return dev; +} + static int lan966x_probe(struct platform_device *pdev) { struct fwnode_handle *ports, *portnp; @@ -1094,6 +1109,7 @@ static int lan966x_probe(struct platform_device *pdev) platform_set_drvdata(pdev, lan966x); lan966x->dev = &pdev->dev; + lan966x->dma_dev = lan966x_get_dma_dev(lan966x->dev); if (!device_get_mac_address(&pdev->dev, mac_addr)) { ether_addr_copy(lan966x->base_mac, mac_addr); diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h index 83c361abb789..3f09f8ddf620 100644 --- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h @@ -270,6 +270,9 @@ struct lan966x_skb_cb { struct lan966x { struct device *dev; + /* Device used for DMA; the PCIe endpoint when enumerated over PCIe. */ + struct device *dma_dev; + u8 num_phys_ports; struct lan966x_port **ports; @@ -573,6 +576,13 @@ void lan966x_fdma_wakeup_netdev(struct lan966x *lan966x); int lan966x_fdma_get_max_frame(struct lan966x *lan966x); int lan966x_qsys_sw_status(struct lan966x *lan966x); +/* dma_dev differs from dev only on the PCIe path. */ +static inline bool lan966x_is_pci(struct lan966x *lan966x) +{ + return IS_ENABLED(CONFIG_MCHP_LAN966X_PCI) && + lan966x->dma_dev != lan966x->dev; +} + int lan966x_lag_port_join(struct lan966x_port *port, struct net_device *brport_dev, struct net_device *bond, -- 2.34.1