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 8216E429036; Thu, 24 Sep 2026 19:57:33 +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=1790279859; cv=none; b=ZTitkuwQziLBuvVlRGGgqjd+ESOJRkA7e7Y4QVZkGjP22c8C0clClGARDfzYXfO2VPs6Qw2d/hlkgehUZN5OSPHUG4lV0R0MR2cj1HYp8FnQcNeuDjoaWH53FXtAcYOPsIrAUaqLWXbS0JBhhk8RMafH17cK0RIXQL+jSVz7zkI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790279859; c=relaxed/simple; bh=7SJDHiTNZUVrA2+aUWyf6Kg0AVhJfh5JdWvOY32Bbt0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:References: In-Reply-To:To:CC; b=EvXS7nYIaRj6XfcLXaLQJyJzEMDDxJcCwQBWaKlB+gOn01VMJcxPr/nhn3Mcyn4WPTxx7GZCThuoYRr/hTVtlHzIP3yQn0eyscYN8raGLPKLmYhjSrSUanq3MhGcIVzGRDhNA+TDWd3X8Z6Xqfi9a54QriGZN4lBUkss53k9ihM= 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=zTWd0o+r; 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="zTWd0o+r" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1790279855; x=1821815855; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=7SJDHiTNZUVrA2+aUWyf6Kg0AVhJfh5JdWvOY32Bbt0=; b=zTWd0o+rs9d+6pLjXi0e5VrOUykp1LZwSE2Kr/oCck491Vol1hI7HYZ9 uYg9/6AhZXAX7qUaeW75q5SlPjhBxOdHHVPmQHdrQ0ZxXDZ4mwWwmU6fo +dA9VhQpWly6C5zDirRvG6Bqq8gY+Mswd3b3O5N2BbUpBeXlQUHTUoIIG rcRHpCoT2jvK/nqepjP8sMwAzsQzG4m52hZb5Cama75UZZUlt2V4ipTo2 rBd9AgCSuNdjR4sO7N/0iDSRiB5QoJYLL5Locct2gfxR4ZhSRSWgS9/fo MpZ+DmFKR5DNrDciR7ZhEB+WwL10nS50k4HgdEjOpmqWgdqdlmK2xVunO Q==; X-CSE-ConnectionGUID: /PA5yiZ3SiimKIT/ka/hMg== X-CSE-MsgGUID: Dj9Q2I9MR1emHWK57xauyw== X-IronPort-AV: E=Sophos;i="6.27,121,1787036400"; d="scan'208";a="64420633" X-Amp-Result: SKIPPED(no attachment in message) Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa2.microchip.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Sep 2026 12:57:33 -0700 Received: from chn-vm-ex04.mchp-main.com (10.10.87.151) by chn-vm-ex2.mchp-main.com (10.10.87.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.2562.49; Thu, 24 Sep 2026 12:57:32 -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; Thu, 24 Sep 2026 12:57:28 -0700 From: Daniel Machon Date: Thu, 24 Sep 2026 21:56:55 +0200 Subject: [PATCH net-next v8 07/15] 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: <20260924-lan966x-pci-fdma-v8-7-201c7b707d8b@microchip.com> References: <20260924-lan966x-pci-fdma-v8-0-201c7b707d8b@microchip.com> In-Reply-To: <20260924-lan966x-pci-fdma-v8-0-201c7b707d8b@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 , "Simon Horman" 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 Reviewed-by: Simon Horman --- .../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 651ea03eede7..ae6e5aec5e13 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)fdma_db_dataptr_get(db) + XDP_PACKET_HEADROOM, fdma_db_len_get(db), @@ -636,11 +636,11 @@ 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; } @@ -656,7 +656,7 @@ 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); @@ -735,9 +735,9 @@ 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; @@ -843,7 +843,7 @@ 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); @@ -993,7 +993,7 @@ 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; } @@ -1015,7 +1015,7 @@ 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