// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
* Copyright (C) 2018-2024 Linaro Ltd.
*/
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/if_rmnet.h>
#include <linux/netdevice.h>
#include <linux/pm_runtime.h>
#include <linux/skbuff.h>
#include <net/pkt_sched.h>
#include <linux/remoteproc/qcom_rproc.h>
#include "ipa.h"
#include "ipa_endpoint.h"
#include "ipa_mem.h"
#include "ipa_modem.h"
#include "ipa_smp2p.h"
#include "ipa_table.h"
#include "ipa_uc.h"
#define IPA_NETDEV_NAME "rmnet_ipa%d"
#define IPA_NETDEV_TAILROOM 0 /* for padding by mux layer */
#define IPA_NETDEV_TIMEOUT 10 /* seconds */
enum ipa_modem_state {
IPA_MODEM_STATE_STOPPED = 0,
IPA_MODEM_STATE_STARTING,
IPA_MODEM_STATE_RUNNING,
IPA_MODEM_STATE_STOPPING,
};
/**
* struct ipa_priv - IPA network device private data
* @ipa: IPA pointer
* @tx: Transmit endpoint pointer
* @rx: Receive endpoint pointer
* @work: Work structure used to wake the modem netdev TX queue
*/
struct ipa_priv {
struct ipa *ipa;
struct ipa_endpoint *tx;
struct ipa_endpoint *rx;
struct work_struct work;
};
/** ipa_open() - Opens the modem network interface */
static int ipa_open(struct net_device *netdev)
{
struct ipa_priv *priv = netdev_priv(netdev);
struct ipa *ipa = priv->ipa;
struct device *dev;
int ret;
dev = ipa->dev;
ret = pm_runtime_get_sync(dev);
if (ret < 0)
goto err_power_put;
ret = ipa_endpoint_enable_one(priv->tx);
if (ret)
goto err_power_put;
ret = ipa_endpoint_enable_one(priv->rx);
if (ret)
goto err_disable_tx;
netif_start_queue(netdev);
pm_runtime_mark_last_busy(dev);
(void)pm_runtime_put_autosuspend(dev);
return 0;
err_disable_tx:
ipa_endpoint_disable_one(priv->tx);
err_power_put:
pm_runtime_put_noidle(dev);
return ret;
}
/** ipa_stop() - Stops the modem network interface. */
static int ipa_stop(struct net_device *netdev)
{
struct ipa_priv *priv = netdev_priv(netdev);
struct ipa *ipa = priv->ipa;
struct device *dev;
int ret;
dev = ipa->dev;
ret = pm_runtime_get_sync(dev);
if (ret < 0)
goto out_power_put;
netif_stop_queue(netdev);
ipa_endpoint_disable_one(priv->rx);
ipa_endpoint_disable_one(priv->tx);
out_power_put:
pm_runtime_mark_last_busy(dev);
(void)pm_runtime_put_autosuspend(dev);
return 0;
}
/** ipa_start_xmit() - Transmit an skb
* @skb: Socket buffer to be transmitted
* @netdev: Network device
*
* Return: NETDEV_TX_OK if successful (or dropped), NETDEV_TX_BUSY otherwise
* Normally NETDEV_TX_OK indicates the buffer was successfully transmitted.
* If the buffer has an unexpected protocol or its size is out of range it
* is quietly dropped, returning NETDEV_TX_OK. NETDEV_TX_BUSY indicates
* the buffer cannot be sent at this time and should retried later.
*/
static netdev_tx_t
ipa_start_xmit(struct sk_buff *skb, struct net_device *netdev)
{
struct net_device_stats *stats = &netdev->stats;
struct ipa_priv *priv = netdev_priv(netdev);
struct ipa_endpoint *endpoint;
struct ipa *ipa = priv->ipa;
u32 skb_len = skb->len;
struct device *dev;
int ret;
if (!skb_len)
goto err_drop_skb;
endpoint = ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX];
if (endpoint->config.qmap && skb->protocol != htons(ETH_P_MAP))
goto err_drop_skb;
/* The hardware must be powered for us to transmit, so if we're not
* ready we want the network stack to stop queueing until power is
* ACTIVE. Once runtime resume has completed, we inform the network
* stack it's OK to try transmitting again.
*
* We learn from pm_runtime_get() whether the hardware is powered.
* If it was not, powering up is either started or already underway.
* And in that case we want to disable queueing, expecting it to be
* re-enabled once power is ACTIVE. But runtime PM and network
* transmit run concurrently, and if we're not careful the requests
* to stop and start queueing could occur in the wrong order.
*
* For that reason we *always* stop queueing here, *before* the call
* to pm_runtime_get(). If we determine here that power is ACTIVE,
* we restart queueing before transmitting the SKB. Otherwise
* queueing will eventually be enabled after resume completes.
*/
netif_stop_queue(netdev);
dev = ipa->dev;
ret = pm_runtime_get(dev);
if (ret < 1) {
/* If a resume won't happen, just drop the packet */
if (ret < 0 && ret != -EINPROGRESS) {
netif_wake_queue(netdev);
pm_runtime_put_noidle(dev);
goto err_drop_skb;
}
pm_runtime_put_noidle(dev);
return NETDEV_TX_BUSY;
}
netif_wake_queue(netdev);
ret = ipa_endpoint_skb_tx(endpoint, skb);
pm_runtime_mark_last_busy(dev);
(void)pm_runtime_put_autosuspend(dev);
if (ret) {
if (ret != -E2BIG)
return NETDEV_TX_BUSY;
goto err_drop_skb;
}
stats->tx_packets++;
stats->tx_bytes += skb_len;
return NETDEV_TX_OK;
err_drop_skb:
dev_kfree_skb_any(skb);
stats->tx_dropped++;
return NETDEV_TX_OK;
}
void ipa_modem_skb_rx(struct net_device *netdev, struct sk_buff *skb)
{
struct net_device_stats *stats = &netdev->stats;
if (skb) {
skb->dev = netdev;
skb->protocol = htons(ETH_P_MAP);
stats->rx_packets++;
stats->rx_bytes += skb->len;
(void)netif_receive_skb(skb);
} else {
stats->rx_dropped++;
}
}
static const struct net_device_ops ipa_modem_ops = {
.ndo_open = ipa_open,
.ndo_stop = ipa_stop,
.ndo_start_xmit = ipa_start_xmit,
};
/** ipa_modem_netdev_setup() - netdev setup function for the modem */
static void ipa_modem_netdev_setup(struct net_device *netdev)
{
netdev->netdev_ops = &ipa_modem_ops;
netdev->header_ops = NULL;
netdev->type = ARPHRD_RAWIP;
netdev->hard_header_len = 0;
netdev->min_header_len = ETH_HLEN;
netdev->min_mtu = ETH_MIN_MTU;
netdev->max_mtu = IPA_MTU;
netdev->mtu = netdev->max_mtu;
netdev->addr_len = 0;
netdev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
netdev->flags &= ~(IFF_BROADCAST | IFF_MULTICAST);
netdev->priv_flags |= IFF_TX_SKB_SHARING;
eth_broadcast_addr(netdev->broadcast);
/* The endpoint is configured for QMAP */
netdev->needed_headroom = sizeof(struct rmnet_map_header);
netdev->needed_tailroom = IPA_NETDEV_TAILROOM;
netdev->watchdog_timeo = IPA_NETDEV_TIMEOUT * HZ;
netdev->hw_features = NETIF_F_SG;
}
/** ipa_modem_suspend() - suspend callback
* @netdev: Network device
*
* Suspend the modem's endpoints.
*/
void ipa_modem_suspend(struct net_device *netdev)
{
struct ipa_priv *priv;
if (!(netdev->flags & IFF_UP))
return;
priv = netdev_priv(netdev);
ipa_endpoint_suspend_one(priv->rx);
ipa_endpoint_suspend_one(priv->tx);
}
/**
* ipa_modem_wake_queue_work() - enable modem netdev queue
* @work: Work structure
*
* Re-enable transmit on the modem network device. This is called
* in (power management) work queue context, scheduled when resuming
* the modem. We can't enable the queue directly in ipa_modem_resume()
* because transmits restart the instant the queue is awakened; but the
* device power state won't be ACTIVE until *after* ipa_modem_resume()
* returns.
*/
static void ipa_modem_wake_queue_work(struct work_struct *work)
{
struct ipa_priv *priv = container_of(work, struct ipa_priv, work);
netif_wake_queue(priv->tx->netdev);
}
/** ipa_modem_resume() - resume callback for runtime_pm
* @dev: pointer to device
*
* Resume the modem's endpoints.
*/
void ipa_modem_resume(struct net_device *netdev)
{
struct ipa_priv *priv;
if (!(netdev->flags & IFF_UP))
return;
priv = netdev_priv(netdev);
ipa_endpoint_resume_one(priv->tx);
ipa_endpoint_resume_one(priv->rx);
/* Arrange for the TX queue to be restarted */
(void)queue_pm_work(&priv->work);
}
int ipa_modem_start(struct ipa *ipa)
{
enum ipa_modem_state state;
struct net_device *netdev;
struct ipa_priv *priv;
int ret;
/* Only attempt to start the modem if it's stopped */
state = atomic_cmpxchg(&ipa->modem_state, IPA_MODEM_STATE_STOPPED,
IPA_MODEM_STATE_STARTING);
/* Silently ignore attempts when running, or when changing state */
if (state != IPA_MODEM_STATE_STOPPED)
return 0;
netdev = alloc_netdev(sizeof(struct ipa_priv), IPA_NETDEV_NAME,
NET_NAME_UNKNOWN, ipa_modem_netdev_setup);
if (!netdev) {
ret = -ENOMEM;
goto out_set_state;
}
SET_NETDEV_DEV(netdev, ipa->dev);
priv = netdev_priv(netdev);
priv->ipa = ipa;
priv->tx = ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX];
priv->rx = ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX];
INIT_WORK(&priv->work, ipa_modem_wake_queue_work);
priv->tx->netdev = netdev;
priv->rx->netdev = netdev;
ipa->modem_netdev = netdev;
ret = register_netdev(netdev);
if (ret) {
ipa->modem_netdev = NULL;
priv->rx->netdev = NULL;
priv->tx->netdev = NULL;
free_netdev(netdev);
}
out_set_state:
if (ret)
atomic_set(&ipa->modem_state, IPA_MODEM_STATE_STOPPED);
else
atomic_set(&ipa->modem_state, IPA_MODEM_STATE_RUNNING);
smp_mb__after_atomic();
return ret;
}
int ipa_modem_stop(struct ipa *ipa)
{
struct net_device *netdev = ipa->modem_netdev;
enum ipa_modem_state state;
/* Only attempt to stop the modem if it's running */
state = atomic_cmpxchg(&ipa->modem_state, IPA_MODEM_STATE_RUNNING,
IPA_MODEM_STATE_STOPPING);
/* Silently ignore attempts when already stopped */
if (state == IPA_MODEM_STATE_STOPPED)
return 0;
/* If we're somewhere between stopped and starting, we're busy */
if (state != IPA_MODEM_STATE_RUNNING)
return -EBUSY;
/* Clean up the netdev and endpoints if it was started */
if (netdev) {
struct ipa_priv *priv = netdev_priv(netdev);
cancel_work_sync(&priv->work);
/* If it was opened, stop it first */
if (netdev->flags & IFF_UP)
(void)ipa_stop(netdev);
unregister_netdev(netdev);
ipa->modem_netdev = NULL;
priv->rx->netdev = NULL;
priv->tx->netdev = NULL;
free_netdev(netdev);
}
atomic_set(&ipa->modem_state, IPA_MODEM_STATE_STOPPED);
smp_mb__after_atomic();
return 0;
}
/* Treat a "clean" modem stop the same as a crash */
static void ipa_modem_crashed(struct ipa *ipa)
{
struct device *dev = ipa->dev;
int ret;
/* Prevent the modem from triggering a call to ipa_setup() */
ipa_smp2p_irq_disable_setup(ipa);
ret = pm_runtime_get_sync(dev);
if (ret < 0) {
dev_err(dev, "error %d getting power to handle crash\n", ret);
goto out_power_put;
}
ipa_endpoint_modem_pause_all(ipa, true);
ipa_endpoint_modem_hol_block_clear_all(ipa);
ipa_table_reset(ipa, true);
ret = ipa_table_hash_flush(ipa);
if (ret)
dev_err(dev, "error %d flushing hash caches\n", ret);
ret = ipa_endpoint_modem_exception_reset_all(ipa);
if (ret)
dev_err(dev, "error %d resetting exception endpoint\n", ret);
ipa_endpoint_modem_pause_all(ipa, false);
ret = ipa_modem_stop(ipa);
if (ret)
dev_err(dev, "error %d stopping modem\n", ret);
/* Now prepare for the next modem boot */
ret = ipa_mem_zero_modem(ipa);
if (ret)
dev_err(dev, "error %d zeroing modem memory regions\n", ret);
out_power_put:
pm_runtime_mark_last_busy(dev);
(void)pm_runtime_put_autosuspend(dev);
}
static int ipa_modem_notify(struct notifier_block *nb, unsigned long action,
void *data)
{
struct ipa *ipa = container_of(nb, struct ipa, nb);
struct qcom_ssr_notify_data *notify_data = data;
struct device *dev = ipa->dev;
switch (action) {
case QCOM_SSR_BEFORE_POWERUP:
dev_info(dev, "received modem starting event\n");
ipa_uc_power(ipa);
ipa_smp2p_notify_reset(ipa);
break;
case QCOM_SSR_AFTER_POWERUP:
dev_info(dev, "received modem running event\n");
break;
case QCOM_SSR_BEFORE_SHUTDOWN:
dev_info(dev, "received modem %s event\n",
notify_data->crashed ? "crashed" : "stopping");
if (ipa->setup_complete)
ipa_modem_crashed(ipa);
break;
case QCOM_SSR_AFTER_SHUTDOWN:
dev_info(dev, "received modem offline event\n");
break;
default:
dev_err(dev, "received unrecognized event %lu\n", action);
break;
}
return NOTIFY_OK;
}
int ipa_modem_config(struct ipa *ipa)
{
void *notifier;
ipa->nb.notifier_call = ipa_modem_notify;
notifier = qcom_register_ssr_notifier("mpss", &ipa->nb);
if (IS_ERR(notifier))
return PTR_ERR(notifier);
ipa->notifier = notifier;
return 0;
}
void ipa_modem_deconfig(struct ipa *ipa)
{
struct device *dev = ipa->dev;
int ret;
ret = qcom_unregister_ssr_notifier(ipa->notifier, &ipa->nb);
if (ret)
dev_err(dev, "error %d unregistering notifier", ret);
ipa->notifier = NULL;
memset(&ipa->nb, 0, sizeof(ipa->nb));
}
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