From patchwork Tue Nov 3 17:23:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Loic Poulain X-Patchwork-Id: 315730 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3EF77C388F7 for ; Tue, 3 Nov 2020 17:17:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE92721556 for ; Tue, 3 Nov 2020 17:17:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="zpeScgSV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728334AbgKCRR2 (ORCPT ); Tue, 3 Nov 2020 12:17:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726581AbgKCRR1 (ORCPT ); Tue, 3 Nov 2020 12:17:27 -0500 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BA6DC0617A6 for ; Tue, 3 Nov 2020 09:17:26 -0800 (PST) Received: by mail-wm1-x344.google.com with SMTP id e2so83765wme.1 for ; Tue, 03 Nov 2020 09:17:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=n+hJQgE05Crtiuy5m4RU64E+kaZzNCCpWVQOxJMO4V4=; b=zpeScgSVfZE4Oc9fiRFd/hddkS/h72uqDjQzfBHQ/eJ58qwzezwtFRWDvfXo/Nam5L XNxvB0Q5WoRaOvGCl8olFeQ+utKTRhoHyQ4gmCRkyY6j+HTjc2HXTAQyXImVMFFcbDk6 sTZINmLJqGPBmNbtsMy9e6pajaC2ruOw0MEz0lxwYhxqz3jA0MeNmx+cWyQuRV4T6mr/ G3ec2qW+EpIZJ1n1WfPiBwk2K3y44H7tnaKPZoSq06abaOqhs/+Fg+UdLmE2RCdeP/SY p4YD9Mgn9NKKvZ8hImut4PgnU5BITGT4b5gzkBnkabT4NooY+fpQO2cz+4+zmZyotBHT 3ljg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=n+hJQgE05Crtiuy5m4RU64E+kaZzNCCpWVQOxJMO4V4=; b=T2n6h3DtxkTXb+baqzfQIn5RutgvIy2p7YDlHujsCHzkEaH74j/vyReRp/99wHY8a/ 7DhjbK2RZ97Ymf5ibF++VqGRtJkQ0GAu5T/GXUfPs7nZOy4PbjYiSH+cl5XU8MVoQJ8c qEsuyj4BtElnzYbZD4rF6Su1vDfXxz3gFJZ2WG9J07QPDdqpzwkv6/hexV8bHxdfRK0H KUg65k4e9zTCXm8MLqQ+nrmHaqkIjXwkTtySaX1k8j4VPW46VJv4giNg6bfpMgNAdEq5 QhuduS0JteL4mCji8BP5DfjvnlY+rfxvQoNyWBCS0CR3EEDodB4JDLnPHtehK6iJm8V7 gQag== X-Gm-Message-State: AOAM530CvHXKESIW+4+XLral6hIBvE08bzKdJ4ZMg1Nxz2pSXPZYRifK eIMBtyUTtJ+GewRX3ZPWWvk3UhQRMLMiExQs X-Google-Smtp-Source: ABdhPJwvs0LfMjYhrOYMJhCUUwNsNcBQkxZEKZ+tChZlmyGwvIBQud29cNxn2DiDKchMJKxhIyOCpw== X-Received: by 2002:a1c:205:: with SMTP id 5mr155727wmc.7.1604423844969; Tue, 03 Nov 2020 09:17:24 -0800 (PST) Received: from localhost.localdomain ([88.122.66.28]) by smtp.gmail.com with ESMTPSA id l124sm3429918wml.48.2020.11.03.09.17.23 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 03 Nov 2020 09:17:24 -0800 (PST) From: Loic Poulain To: kuba@kernel.org, davem@davemloft.net Cc: netdev@vger.kernel.org, linux-arm-msm@vger.kernel.org, bbhatt@codeaurora.org, willemdebruijn.kernel@gmail.com, jhugo@codeaurora.org, manivannan.sadhasivam@linaro.org, hemantk@codeaurora.org, Loic Poulain Subject: [PATCH v10 1/2] bus: mhi: Add mhi_queue_is_full function Date: Tue, 3 Nov 2020 18:23:53 +0100 Message-Id: <1604424234-24446-1-git-send-email-loic.poulain@linaro.org> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This function can be used by client driver to determine whether it's possible to queue new elements in a channel ring. Signed-off-by: Loic Poulain Reviewed-by: Manivannan Sadhasivam --- v1->v5: not part of the series v6: Add this commit, used for stopping TX queue v7: no change v8: remove static change (up to the compiler) v9: no change + Mani reviewed-by tag v10: no change drivers/bus/mhi/core/main.c | 11 +++++++++++ include/linux/mhi.h | 7 +++++++ 2 files changed, 18 insertions(+) diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index a588eac..bab38d2 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -1173,6 +1173,17 @@ int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir, } EXPORT_SYMBOL_GPL(mhi_queue_buf); +bool mhi_queue_is_full(struct mhi_device *mhi_dev, enum dma_data_direction dir) +{ + struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; + struct mhi_chan *mhi_chan = (dir == DMA_TO_DEVICE) ? + mhi_dev->ul_chan : mhi_dev->dl_chan; + struct mhi_ring *tre_ring = &mhi_chan->tre_ring; + + return mhi_is_ring_full(mhi_cntrl, tre_ring); +} +EXPORT_SYMBOL_GPL(mhi_queue_is_full); + int mhi_send_cmd(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan, enum mhi_cmd_type cmd) diff --git a/include/linux/mhi.h b/include/linux/mhi.h index 9d67e75..f72c3a4 100644 --- a/include/linux/mhi.h +++ b/include/linux/mhi.h @@ -745,4 +745,11 @@ int mhi_queue_buf(struct mhi_device *mhi_dev, enum dma_data_direction dir, int mhi_queue_skb(struct mhi_device *mhi_dev, enum dma_data_direction dir, struct sk_buff *skb, size_t len, enum mhi_flags mflags); +/** + * mhi_queue_is_full - Determine whether queueing new elements is possible + * @mhi_dev: Device associated with the channels + * @dir: DMA direction for the channel + */ +bool mhi_queue_is_full(struct mhi_device *mhi_dev, enum dma_data_direction dir); + #endif /* _MHI_H_ */ From patchwork Tue Nov 3 17:23:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Loic Poulain X-Patchwork-Id: 320436 Delivered-To: patch@linaro.org Received: by 2002:a92:7b12:0:0:0:0:0 with SMTP id w18csp4760816ilc; Tue, 3 Nov 2020 09:17:32 -0800 (PST) X-Google-Smtp-Source: ABdhPJz87QZpmJ9P7X+d5x+t25CCtVpdHUR1Dc35U0aWtS7yKGoTRZS0Cfvn8+k5AnlZervt7Ry9 X-Received: by 2002:a17:907:2166:: with SMTP id rl6mr9469987ejb.61.1604423851860; Tue, 03 Nov 2020 09:17:31 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1604423851; cv=none; d=google.com; s=arc-20160816; b=DHL2olcygcliq6kwZQTXfJVV42qpzIwsBqOhlN/aXSgCkWkOhF4CUTH6OxwRnbQsMM 1sJO9dCyLAs3lRGBoywnN3DrsPv7VgnRFM31Sp0uceCQbor7yVe3GFdZ+lhHcpl2of6R +3jASX4s09zzubGGLk0q8HiAGPeKfR/tjp0q/4J5bL3U6sqtmCFpq0q7O6sHvFzT3SHz XS6ygXoi104adFqVDpTwXufDnmTftUA7btKn6/a/0FSzh+30kIpkPutOm5ppPEMxT3wg K3CqPKKgCFz0NrlrBTALu1d0Y5ic+v0B8IfyQcoib5lYqP7aUbyWItuqXZtAXCJIq6bJ tkGQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:references:in-reply-to:message-id:date:subject :cc:to:from:dkim-signature; bh=jyHgUMR+LPCRi1nwDCftPAhrkL65HUZNh8Dhv6zfFNU=; b=iG7g5Fg9F1Jppxg9gD77VqgnsoF8v+6BQy5FXhwfegKabbgKLNdYgnFls9SHIlziVe oiifeoqtQUrJ8E8nayOwD0uD3rFMLMLeEjN6B4Af8ucNkqqeQnN+svR2eFbCH7JNdc8q xAf2g1htuWOiqwF/5QgSHUleAp93a3xjoKIPBZSpRzbdIZolVE2TjzJD/OCL6NmazGZX fjBj9z3pCnuEt3psBTNmEtOCxjOehKlNrhYYJX2uoqPh8hbmRHyDag+Fs3NC+eCpxOa+ EsJwX5aqc3wVAEiUV5Cn04hOJ4tg8ZGIagsWvq2intZeghBkuTmoc756k0jCpCX0HuC3 4MfQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=FaQkJcxC; spf=pass (google.com: domain of netdev-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=netdev-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id by24si12128003ejc.347.2020.11.03.09.17.31; Tue, 03 Nov 2020 09:17:31 -0800 (PST) Received-SPF: pass (google.com: domain of netdev-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=FaQkJcxC; spf=pass (google.com: domain of netdev-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=netdev-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728586AbgKCRR2 (ORCPT + 8 others); Tue, 3 Nov 2020 12:17:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728379AbgKCRR2 (ORCPT ); Tue, 3 Nov 2020 12:17:28 -0500 Received: from mail-wr1-x444.google.com (mail-wr1-x444.google.com [IPv6:2a00:1450:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 080B1C0617A6 for ; Tue, 3 Nov 2020 09:17:28 -0800 (PST) Received: by mail-wr1-x444.google.com with SMTP id b3so13435818wrx.11 for ; Tue, 03 Nov 2020 09:17:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=jyHgUMR+LPCRi1nwDCftPAhrkL65HUZNh8Dhv6zfFNU=; b=FaQkJcxCfyNZomlBAKzWYU05mmaUmoUQQqmaNr1al9hpZ5idpBr10UEwt9CDt85lRp jOVYGIZe7uf6x+iTq6NUgnJARgQXEsop8gxsGOb86YaJSVYectGxFKvYvdqPuL2cTtbp dyrS0fcsVJqMxT0vpSKb5jFonbrT+7QJolFUBkXGhlqLpoofEpYUO5w8Svg3dgFx2rI1 fkXUl00rt+hE0wHva0OYg5d+q4GsP3gGgZ1z+DLTQ0EF+n7Y886jkpYURpVQopJDYDxv IWcAJxUFKgCkxdKdpoDW7M7xyKSipqfxhItp6dOOPZAV3vpsefY5eV71czlBqqMGb+qK Ivig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=jyHgUMR+LPCRi1nwDCftPAhrkL65HUZNh8Dhv6zfFNU=; b=gao3x2sL/XchQTY6twcziPj54L0cU/cy0v+vCF7QRLGEAekwcJgeq7gKDCNMfOdAmJ eyg35OTgHE163YjdhiY6ggySiKLgUe4bReqHHQ8/CIAwDXs5DBwXFNkncXS5i2mqrVkF EozFu6Zv3aDpnIwlIuTJfhx66/ybtxIytxdJ0JxuT2OC0g+vhxdGi5mboAh481MDua6C o0ABAs9PzmoGsTyt8qIYQ2tc7e9xWfMV+T/Bn7z+ijrJ3M7zH/sKgy3Xmlr5G17BTqhZ eExyjhPaTxl+SgytgX72C2P3yimUq8WM9q0+V/o2W7dZF+U7UGlZycPMxN5SYYQUDqxW b2Gw== X-Gm-Message-State: AOAM532QEGVcJywwBeCXsy/3KF5gjrqs51QcHu4RHewOz0I4D0Td9SmS e7TKQZrc7QRs/Xa+A/FlfXqejQ== X-Received: by 2002:adf:dec1:: with SMTP id i1mr25972567wrn.50.1604423846498; Tue, 03 Nov 2020 09:17:26 -0800 (PST) Received: from localhost.localdomain ([88.122.66.28]) by smtp.gmail.com with ESMTPSA id l124sm3429918wml.48.2020.11.03.09.17.25 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 03 Nov 2020 09:17:26 -0800 (PST) From: Loic Poulain To: kuba@kernel.org, davem@davemloft.net Cc: netdev@vger.kernel.org, linux-arm-msm@vger.kernel.org, bbhatt@codeaurora.org, willemdebruijn.kernel@gmail.com, jhugo@codeaurora.org, manivannan.sadhasivam@linaro.org, hemantk@codeaurora.org, Loic Poulain Subject: [PATCH v10 2/2] net: Add mhi-net driver Date: Tue, 3 Nov 2020 18:23:54 +0100 Message-Id: <1604424234-24446-2-git-send-email-loic.poulain@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1604424234-24446-1-git-send-email-loic.poulain@linaro.org> References: <1604424234-24446-1-git-send-email-loic.poulain@linaro.org> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch adds a new network driver implementing MHI transport for network packets. Packets can be in any format, though QMAP (rmnet) is the usual protocol (flow control + PDN mux). It support two MHI devices, IP_HW0 which is, the path to the IPA (IP accelerator) on qcom modem, And IP_SW0 which is the software driven IP path (to modem CPU). Signed-off-by: Loic Poulain Reviewed-by: Manivannan Sadhasivam --- v2: - rebase on net-next - remove useless skb_linearize - check error type on mhi_queue return - rate limited errors - Schedule RX refill only on 'low' buf level - SET_NETDEV_DEV in probe - reorder device remove sequence v3: - Stop channels on net_register error - Remove useles parentheses - Add driver .owner v4: - prevent potential cpu hog in rx-refill loop - Access mtu via READ_ONCE v5: - Fix access to u64 stats v6: - Stop TX queue earlier if queue is full - Preventing 'abnormal' NETDEV_TX_BUSY path v7: - Stop dl/ul cb operations on channel resetting v8: - remove premature comment about TX threading gain - check rx_queued to determine queuing limits - fix probe error path (unified goto usage) v9: - fix coding style and comments for MHI bus - remove useless mhi_unprepare in probe (done by mhi core) v10: - use dev_kfree_skb_any in unknown context - do-while to while loop for rx queueing drivers/net/Kconfig | 7 ++ drivers/net/Makefile | 1 + drivers/net/mhi_net.c | 316 ++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 324 insertions(+) create mode 100644 drivers/net/mhi_net.c -- 2.7.4 diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index 1368d1d..ef830ed 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -426,6 +426,13 @@ config VSOCKMON mostly intended for developers or support to debug vsock issues. If unsure, say N. +config MHI_NET + tristate "MHI network driver" + depends on MHI_BUS + help + This is the network driver for MHI bus. It can be used with + QCOM based WWAN modems (like SDX55). Say Y or M. + endif # NET_CORE config SUNGEM_PHY diff --git a/drivers/net/Makefile b/drivers/net/Makefile index 94b6080..8312037 100644 --- a/drivers/net/Makefile +++ b/drivers/net/Makefile @@ -34,6 +34,7 @@ obj-$(CONFIG_GTP) += gtp.o obj-$(CONFIG_NLMON) += nlmon.o obj-$(CONFIG_NET_VRF) += vrf.o obj-$(CONFIG_VSOCKMON) += vsockmon.o +obj-$(CONFIG_MHI_NET) += mhi_net.o # # Networking Drivers diff --git a/drivers/net/mhi_net.c b/drivers/net/mhi_net.c new file mode 100644 index 0000000..d3f9278 --- /dev/null +++ b/drivers/net/mhi_net.c @@ -0,0 +1,316 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* MHI Network driver - Network over MHI bus + * + * Copyright (C) 2020 Linaro Ltd + */ + +#include +#include +#include +#include +#include +#include +#include + +#define MHI_NET_MIN_MTU ETH_MIN_MTU +#define MHI_NET_MAX_MTU 0xffff +#define MHI_NET_DEFAULT_MTU 0x4000 + +struct mhi_net_stats { + u64_stats_t rx_packets; + u64_stats_t rx_bytes; + u64_stats_t rx_errors; + u64_stats_t rx_dropped; + u64_stats_t tx_packets; + u64_stats_t tx_bytes; + u64_stats_t tx_errors; + u64_stats_t tx_dropped; + atomic_t rx_queued; + struct u64_stats_sync tx_syncp; + struct u64_stats_sync rx_syncp; +}; + +struct mhi_net_dev { + struct mhi_device *mdev; + struct net_device *ndev; + struct delayed_work rx_refill; + struct mhi_net_stats stats; + u32 rx_queue_sz; +}; + +static int mhi_ndo_open(struct net_device *ndev) +{ + struct mhi_net_dev *mhi_netdev = netdev_priv(ndev); + + /* Feed the rx buffer pool */ + schedule_delayed_work(&mhi_netdev->rx_refill, 0); + + /* Carrier is established via out-of-band channel (e.g. qmi) */ + netif_carrier_on(ndev); + + netif_start_queue(ndev); + + return 0; +} + +static int mhi_ndo_stop(struct net_device *ndev) +{ + struct mhi_net_dev *mhi_netdev = netdev_priv(ndev); + + netif_stop_queue(ndev); + netif_carrier_off(ndev); + cancel_delayed_work_sync(&mhi_netdev->rx_refill); + + return 0; +} + +static int mhi_ndo_xmit(struct sk_buff *skb, struct net_device *ndev) +{ + struct mhi_net_dev *mhi_netdev = netdev_priv(ndev); + struct mhi_device *mdev = mhi_netdev->mdev; + int err; + + err = mhi_queue_skb(mdev, DMA_TO_DEVICE, skb, skb->len, MHI_EOT); + if (unlikely(err)) { + net_err_ratelimited("%s: Failed to queue TX buf (%d)\n", + ndev->name, err); + + u64_stats_update_begin(&mhi_netdev->stats.tx_syncp); + u64_stats_inc(&mhi_netdev->stats.tx_dropped); + u64_stats_update_end(&mhi_netdev->stats.tx_syncp); + + /* drop the packet */ + dev_kfree_skb_any(skb); + } + + if (mhi_queue_is_full(mdev, DMA_TO_DEVICE)) + netif_stop_queue(ndev); + + return NETDEV_TX_OK; +} + +static void mhi_ndo_get_stats64(struct net_device *ndev, + struct rtnl_link_stats64 *stats) +{ + struct mhi_net_dev *mhi_netdev = netdev_priv(ndev); + unsigned int start; + + do { + start = u64_stats_fetch_begin_irq(&mhi_netdev->stats.rx_syncp); + stats->rx_packets = u64_stats_read(&mhi_netdev->stats.rx_packets); + stats->rx_bytes = u64_stats_read(&mhi_netdev->stats.rx_bytes); + stats->rx_errors = u64_stats_read(&mhi_netdev->stats.rx_errors); + stats->rx_dropped = u64_stats_read(&mhi_netdev->stats.rx_dropped); + } while (u64_stats_fetch_retry_irq(&mhi_netdev->stats.rx_syncp, start)); + + do { + start = u64_stats_fetch_begin_irq(&mhi_netdev->stats.tx_syncp); + stats->tx_packets = u64_stats_read(&mhi_netdev->stats.tx_packets); + stats->tx_bytes = u64_stats_read(&mhi_netdev->stats.tx_bytes); + stats->tx_errors = u64_stats_read(&mhi_netdev->stats.tx_errors); + stats->tx_dropped = u64_stats_read(&mhi_netdev->stats.tx_dropped); + } while (u64_stats_fetch_retry_irq(&mhi_netdev->stats.tx_syncp, start)); +} + +static const struct net_device_ops mhi_netdev_ops = { + .ndo_open = mhi_ndo_open, + .ndo_stop = mhi_ndo_stop, + .ndo_start_xmit = mhi_ndo_xmit, + .ndo_get_stats64 = mhi_ndo_get_stats64, +}; + +static void mhi_net_setup(struct net_device *ndev) +{ + ndev->header_ops = NULL; /* No header */ + ndev->type = ARPHRD_NONE; /* QMAP... */ + ndev->hard_header_len = 0; + ndev->addr_len = 0; + ndev->flags = IFF_POINTOPOINT | IFF_NOARP; + ndev->netdev_ops = &mhi_netdev_ops; + ndev->mtu = MHI_NET_DEFAULT_MTU; + ndev->min_mtu = MHI_NET_MIN_MTU; + ndev->max_mtu = MHI_NET_MAX_MTU; + ndev->tx_queue_len = 1000; +} + +static void mhi_net_dl_callback(struct mhi_device *mhi_dev, + struct mhi_result *mhi_res) +{ + struct mhi_net_dev *mhi_netdev = dev_get_drvdata(&mhi_dev->dev); + struct sk_buff *skb = mhi_res->buf_addr; + int remaining; + + remaining = atomic_dec_return(&mhi_netdev->stats.rx_queued); + + if (unlikely(mhi_res->transaction_status)) { + dev_kfree_skb_any(skb); + + /* MHI layer stopping/resetting the DL channel */ + if (mhi_res->transaction_status == -ENOTCONN) + return; + + u64_stats_update_begin(&mhi_netdev->stats.rx_syncp); + u64_stats_inc(&mhi_netdev->stats.rx_errors); + u64_stats_update_end(&mhi_netdev->stats.rx_syncp); + } else { + u64_stats_update_begin(&mhi_netdev->stats.rx_syncp); + u64_stats_inc(&mhi_netdev->stats.rx_packets); + u64_stats_add(&mhi_netdev->stats.rx_bytes, mhi_res->bytes_xferd); + u64_stats_update_end(&mhi_netdev->stats.rx_syncp); + + skb->protocol = htons(ETH_P_MAP); + skb_put(skb, mhi_res->bytes_xferd); + netif_rx(skb); + } + + /* Refill if RX buffers queue becomes low */ + if (remaining <= mhi_netdev->rx_queue_sz / 2) + schedule_delayed_work(&mhi_netdev->rx_refill, 0); +} + +static void mhi_net_ul_callback(struct mhi_device *mhi_dev, + struct mhi_result *mhi_res) +{ + struct mhi_net_dev *mhi_netdev = dev_get_drvdata(&mhi_dev->dev); + struct net_device *ndev = mhi_netdev->ndev; + struct sk_buff *skb = mhi_res->buf_addr; + + /* Hardware has consumed the buffer, so free the skb (which is not + * freed by the MHI stack) and perform accounting. + */ + dev_consume_skb_any(skb); + + u64_stats_update_begin(&mhi_netdev->stats.tx_syncp); + if (unlikely(mhi_res->transaction_status)) { + + /* MHI layer stopping/resetting the UL channel */ + if (mhi_res->transaction_status == -ENOTCONN) { + u64_stats_update_end(&mhi_netdev->stats.tx_syncp); + return; + } + + u64_stats_inc(&mhi_netdev->stats.tx_errors); + } else { + u64_stats_inc(&mhi_netdev->stats.tx_packets); + u64_stats_add(&mhi_netdev->stats.tx_bytes, mhi_res->bytes_xferd); + } + u64_stats_update_end(&mhi_netdev->stats.tx_syncp); + + if (netif_queue_stopped(ndev)) + netif_wake_queue(ndev); +} + +static void mhi_net_rx_refill_work(struct work_struct *work) +{ + struct mhi_net_dev *mhi_netdev = container_of(work, struct mhi_net_dev, + rx_refill.work); + struct net_device *ndev = mhi_netdev->ndev; + struct mhi_device *mdev = mhi_netdev->mdev; + int size = READ_ONCE(ndev->mtu); + struct sk_buff *skb; + int err; + + while (atomic_read(&mhi_netdev->stats.rx_queued) < mhi_netdev->rx_queue_sz) { + skb = netdev_alloc_skb(ndev, size); + if (unlikely(!skb)) + break; + + err = mhi_queue_skb(mdev, DMA_FROM_DEVICE, skb, size, MHI_EOT); + if (unlikely(err)) { + net_err_ratelimited("%s: Failed to queue RX buf (%d)\n", + ndev->name, err); + kfree_skb(skb); + break; + } + + atomic_inc(&mhi_netdev->stats.rx_queued); + + /* Do not hog the CPU if rx buffers are consumed faster than + * queued (unlikely). + */ + cond_resched(); + } + + /* If we're still starved of rx buffers, reschedule later */ + if (unlikely(!atomic_read(&mhi_netdev->stats.rx_queued))) + schedule_delayed_work(&mhi_netdev->rx_refill, HZ / 2); +} + +static int mhi_net_probe(struct mhi_device *mhi_dev, + const struct mhi_device_id *id) +{ + const char *netname = (char *)id->driver_data; + struct device *dev = &mhi_dev->dev; + struct mhi_net_dev *mhi_netdev; + struct net_device *ndev; + int err; + + ndev = alloc_netdev(sizeof(*mhi_netdev), netname, NET_NAME_PREDICTABLE, + mhi_net_setup); + if (!ndev) + return -ENOMEM; + + mhi_netdev = netdev_priv(ndev); + dev_set_drvdata(dev, mhi_netdev); + mhi_netdev->ndev = ndev; + mhi_netdev->mdev = mhi_dev; + SET_NETDEV_DEV(ndev, &mhi_dev->dev); + + /* All MHI net channels have 128 ring elements (at least for now) */ + mhi_netdev->rx_queue_sz = 128; + + INIT_DELAYED_WORK(&mhi_netdev->rx_refill, mhi_net_rx_refill_work); + u64_stats_init(&mhi_netdev->stats.rx_syncp); + u64_stats_init(&mhi_netdev->stats.tx_syncp); + + /* Start MHI channels */ + err = mhi_prepare_for_transfer(mhi_dev); + if (err) + goto out_err; + + err = register_netdev(ndev); + if (err) + goto out_err; + + return 0; + +out_err: + free_netdev(ndev); + return err; +} + +static void mhi_net_remove(struct mhi_device *mhi_dev) +{ + struct mhi_net_dev *mhi_netdev = dev_get_drvdata(&mhi_dev->dev); + + unregister_netdev(mhi_netdev->ndev); + + mhi_unprepare_from_transfer(mhi_netdev->mdev); + + free_netdev(mhi_netdev->ndev); +} + +static const struct mhi_device_id mhi_net_id_table[] = { + { .chan = "IP_HW0", .driver_data = (kernel_ulong_t)"mhi_hwip%d" }, + { .chan = "IP_SW0", .driver_data = (kernel_ulong_t)"mhi_swip%d" }, + {} +}; +MODULE_DEVICE_TABLE(mhi, mhi_net_id_table); + +static struct mhi_driver mhi_net_driver = { + .probe = mhi_net_probe, + .remove = mhi_net_remove, + .dl_xfer_cb = mhi_net_dl_callback, + .ul_xfer_cb = mhi_net_ul_callback, + .id_table = mhi_net_id_table, + .driver = { + .name = "mhi_net", + .owner = THIS_MODULE, + }, +}; + +module_mhi_driver(mhi_net_driver); + +MODULE_AUTHOR("Loic Poulain "); +MODULE_DESCRIPTION("Network over MHI"); +MODULE_LICENSE("GPL v2");