net: Add mhi-net driver
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 <loic.poulain@linaro.org> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Link: https://lore.kernel.org/r/1604424234-24446-2-git-send-email-loic.poulain@linaro.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Loic Poulain
Jakub Kicinski
parent
d8c4a22363
commit
3ffec6a14f
@ -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
|
||||
|
||||
@ -36,6 +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
|
||||
|
||||
#
|
||||
# Networking Drivers
|
||||
|
||||
316
drivers/net/mhi_net.c
Normal file
316
drivers/net/mhi_net.c
Normal file
@ -0,0 +1,316 @@
|
||||
// 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;
|
||||
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 <loic.poulain@linaro.org>");
|
||||
MODULE_DESCRIPTION("Network over MHI");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
Loading…
Reference in New Issue
Block a user