[net-next,v3,2/5] net: mhi: Add dedicated folder

Message ID	1612462661-23045-3-git-send-email-loic.poulain@linaro.org (mailing list archive)
State	Superseded
Delegated to:	Netdev Maintainers
Headers	show Return-Path: <netdev-owner@kernel.org> From: Loic Poulain <loic.poulain@linaro.org> To: kuba@kernel.org, davem@davemloft.net Cc: netdev@vger.kernel.org, bjorn@mork.no, dcbw@redhat.com, carl.yin@quectel.com, mpearson@lenovo.com, cchen50@lenovo.com, jwjiang@lenovo.com, ivan.zhang@quectel.com, naveen.kumar@quectel.com, Loic Poulain <loic.poulain@linaro.org> Subject: [PATCH net-next v3 2/5] net: mhi: Add dedicated folder Date: Thu, 4 Feb 2021 19:17:38 +0100 Message-Id: <1612462661-23045-3-git-send-email-loic.poulain@linaro.org> In-Reply-To: <1612462661-23045-1-git-send-email-loic.poulain@linaro.org> References: <1612462661-23045-1-git-send-email-loic.poulain@linaro.org> Precedence: bulk
Series	Add MBIM over MHI support \| expand [net-next,v3,0/5] Add MBIM over MHI support [net-next,v3,1/5] net: mhi: Add protocol support [net-next,v3,2/5] net: mhi: Add dedicated folder [net-next,v3,3/5] net: mhi: Create mhi.h [net-next,v3,4/5] net: mhi: Add rx_length_errors stat [net-next,v3,5/5] net: mhi: Add mbim proto

Context	Check	Description
netdev/apply	fail	Patch does not apply to net-next
netdev/tree_selection	success	Clearly marked for net-next

diff --git a/drivers/net/Makefile b/drivers/net/Makefile index 36e2e41..f4990ff 100644 --- a/drivers/net/Makefile +++ b/drivers/net/Makefile @@ -36,7 +36,7 @@ obj-$(CONFIG_GTP) += gtp.o obj-$(CONFIG_NLMON) += nlmon.o obj-$(CONFIG_NET_VRF) += vrf.o obj-$(CONFIG_VSOCKMON) += vsockmon.o -obj-$(CONFIG_MHI_NET) += mhi_net.o +obj-$(CONFIG_MHI_NET) += mhi/ # # Networking Drivers diff --git a/drivers/net/mhi/Makefile b/drivers/net/mhi/Makefile new file mode 100644 index 0000000..0acf989 --- /dev/null +++ b/drivers/net/mhi/Makefile @@ -0,0 +1,3 @@ +obj-$(CONFIG_MHI_NET) += mhi_net.o + +mhi_net-y := net.o diff --git a/drivers/net/mhi/net.c b/drivers/net/mhi/net.c new file mode 100644 index 0000000..b92c2e1 --- /dev/null +++ b/drivers/net/mhi/net.c @@ -0,0 +1,429 @@ +// 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"); diff --git a/drivers/net/mhi_net.c b/drivers/net/mhi_net.c deleted file mode 100644 index b92c2e1..0000000 --- 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");

[net-next,v3,2/5] net: mhi: Add dedicated folder

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