net: mhi: Add dedicated folder

Create a dedicated mhi directory for mhi-net, mhi-net is going to
be split into differente files (for additional protocol support).

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 429 deletions

diff --git a/drivers/net/mhi_net.c b/drivers/net/mhi_net.c
deleted file mode 100644
index b92c2e1f107e..000000000000
--- a/drivers/net/mhi_net.c
+++ /dev/null
@@ -1,429 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/* MHI Network driver - Network over MHI bus
- *
- * Copyright (C) 2020 Linaro Ltd <loic.poulain@linaro.org>
- */
-
-#include <linux/if_arp.h>
-#include <linux/mhi.h>
-#include <linux/mod_devicetable.h>
-#include <linux/module.h>
-#include <linux/netdevice.h>
-#include <linux/skbuff.h>
-#include <linux/u64_stats_sync.h>
-
-#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;
-	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 sk_buff *skbagg_head;
-	struct sk_buff *skbagg_tail;
-	const struct mhi_net_proto *proto;
-	void *proto_data;
-	struct delayed_work rx_refill;
-	struct mhi_net_stats stats;
-	u32 rx_queue_sz;
-};
-
-struct mhi_net_proto {
-	int (*init)(struct mhi_net_dev *mhi_netdev);
-	struct sk_buff * (*tx_fixup)(struct mhi_net_dev *mhi_netdev, struct sk_buff *skb);
-	void (*rx)(struct mhi_net_dev *mhi_netdev, struct sk_buff *skb);
-};
-
-struct mhi_device_info {
-	const char *netname;
-	const struct mhi_net_proto *proto;
-};
-
-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);
-	const struct mhi_net_proto *proto = mhi_netdev->proto;
-	struct mhi_device *mdev = mhi_netdev->mdev;
-	int err;
-
-	if (proto && proto->tx_fixup) {
-		skb = proto->tx_fixup(mhi_netdev, skb);
-		if (unlikely(!skb))
-			goto exit_drop;
-	}
-
-	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);
-		dev_kfree_skb_any(skb);
-		goto exit_drop;
-	}
-
-	if (mhi_queue_is_full(mdev, DMA_TO_DEVICE))
-		netif_stop_queue(ndev);
-
-	return NETDEV_TX_OK;
-
-exit_drop:
-	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);
-
-	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_RAWIP;
-	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 struct sk_buff *mhi_net_skb_agg(struct mhi_net_dev *mhi_netdev,
-				       struct sk_buff *skb)
-{
-	struct sk_buff *head = mhi_netdev->skbagg_head;
-	struct sk_buff *tail = mhi_netdev->skbagg_tail;
-
-	/* This is non-paged skb chaining using frag_list */
-	if (!head) {
-		mhi_netdev->skbagg_head = skb;
-		return skb;
-	}
-
-	if (!skb_shinfo(head)->frag_list)
-		skb_shinfo(head)->frag_list = skb;
-	else
-		tail->next = skb;
-
-	head->len += skb->len;
-	head->data_len += skb->len;
-	head->truesize += skb->truesize;
-
-	mhi_netdev->skbagg_tail = skb;
-
-	return mhi_netdev->skbagg_head;
-}
-
-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);
-	const struct mhi_net_proto *proto = mhi_netdev->proto;
-	struct sk_buff *skb = mhi_res->buf_addr;
-	int free_desc_count;
-
-	free_desc_count = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE);
-
-	if (unlikely(mhi_res->transaction_status)) {
-		switch (mhi_res->transaction_status) {
-		case -EOVERFLOW:
-			/* Packet can not fit in one MHI buffer and has been
-			 * split over multiple MHI transfers, do re-aggregation.
-			 * That usually means the device side MTU is larger than
-			 * the host side MTU/MRU. Since this is not optimal,
-			 * print a warning (once).
-			 */
-			netdev_warn_once(mhi_netdev->ndev,
-					 "Fragmented packets received, fix MTU?\n");
-			skb_put(skb, mhi_res->bytes_xferd);
-			mhi_net_skb_agg(mhi_netdev, skb);
-			break;
-		case -ENOTCONN:
-			/* MHI layer stopping/resetting the DL channel */
-			dev_kfree_skb_any(skb);
-			return;
-		default:
-			/* Unknown error, simply drop */
-			dev_kfree_skb_any(skb);
-			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 {
-		skb_put(skb, mhi_res->bytes_xferd);
-
-		if (mhi_netdev->skbagg_head) {
-			/* Aggregate the final fragment */
-			skb = mhi_net_skb_agg(mhi_netdev, skb);
-			mhi_netdev->skbagg_head = NULL;
-		}
-
-		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, skb->len);
-		u64_stats_update_end(&mhi_netdev->stats.rx_syncp);
-
-		switch (skb->data[0] & 0xf0) {
-		case 0x40:
-			skb->protocol = htons(ETH_P_IP);
-			break;
-		case 0x60:
-			skb->protocol = htons(ETH_P_IPV6);
-			break;
-		default:
-			skb->protocol = htons(ETH_P_MAP);
-			break;
-		}
-
-		if (proto && proto->rx)
-			proto->rx(mhi_netdev, skb);
-		else
-			netif_rx(skb);
-	}
-
-	/* Refill if RX buffers queue becomes low */
-	if (free_desc_count >= 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 mhi_device *mdev = mhi_netdev->mdev;
-	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) && !mhi_queue_is_full(mdev, DMA_TO_DEVICE))
-		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 (!mhi_queue_is_full(mdev, DMA_FROM_DEVICE)) {
-		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;
-		}
-
-		/* 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 (mhi_get_free_desc_count(mdev, DMA_FROM_DEVICE) == mhi_netdev->rx_queue_sz)
-		schedule_delayed_work(&mhi_netdev->rx_refill, HZ / 2);
-}
-
-static struct device_type wwan_type = {
-	.name = "wwan",
-};
-
-static int mhi_net_probe(struct mhi_device *mhi_dev,
-			 const struct mhi_device_id *id)
-{
-	const struct mhi_device_info *info = (struct mhi_device_info *)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), info->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;
-	mhi_netdev->skbagg_head = NULL;
-	mhi_netdev->proto = info->proto;
-	SET_NETDEV_DEV(ndev, &mhi_dev->dev);
-	SET_NETDEV_DEVTYPE(ndev, &wwan_type);
-
-	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;
-
-	/* Number of transfer descriptors determines size of the queue */
-	mhi_netdev->rx_queue_sz = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE);
-
-	err = register_netdev(ndev);
-	if (err)
-		goto out_err;
-
-	if (mhi_netdev->proto) {
-		err = mhi_netdev->proto->init(mhi_netdev);
-		if (err)
-			goto out_err_proto;
-	}
-
-	return 0;
-
-out_err_proto:
-	unregister_netdev(ndev);
-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);
-
-	if (mhi_netdev->skbagg_head)
-		kfree_skb(mhi_netdev->skbagg_head);
-
-	free_netdev(mhi_netdev->ndev);
-}
-
-static const struct mhi_device_info mhi_hwip0 = {
-	.netname = "mhi_hwip%d",
-};
-
-static const struct mhi_device_info mhi_swip0 = {
-	.netname = "mhi_swip%d",
-};
-
-static const struct mhi_device_id mhi_net_id_table[] = {
-	/* Hardware accelerated data PATH (to modem IPA), protocol agnostic */
-	{ .chan = "IP_HW0", .driver_data = (kernel_ulong_t)&mhi_hwip0 },
-	/* Software data PATH (to modem CPU) */
-	{ .chan = "IP_SW0", .driver_data = (kernel_ulong_t)&mhi_swip0 },
-	{}
-};
-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 <loic.poulain@linaro.org>");
-MODULE_DESCRIPTION("Network over MHI");
-MODULE_LICENSE("GPL v2");