1 files changed, 478 insertions, 0 deletions
diff --git a/drivers/net/ipa/ipa_modem.c b/drivers/net/ipa/ipa_modem.c
new file mode 100644
index 0000000000..423422a2a4
--- /dev/null
+++ b/drivers/net/ipa/ipa_modem.c
@@ -0,0 +1,478 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2018-2022 Linaro Ltd.
+ */
+
+#include <linux/errno.h>
+#include <linux/if_arp.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/if_rmnet.h>
+#include <linux/etherdevice.h>
+#include <net/pkt_sched.h>
+#include <linux/pm_runtime.h>
+#include <linux/remoteproc/qcom_rproc.h>
+
+#include "ipa.h"
+#include "ipa_data.h"
+#include "ipa_endpoint.h"
+#include "ipa_table.h"
+#include "ipa_mem.h"
+#include "ipa_modem.h"
+#include "ipa_smp2p.h"
+#include "ipa_qmi.h"
+#include "ipa_uc.h"
+#include "ipa_power.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
+ * @work:	Work structure used to wake the modem netdev TX queue
+ */
+struct ipa_priv {
+	struct ipa *ipa;
+	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->pdev->dev;
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0)
+		goto err_power_put;
+
+	ret = ipa_endpoint_enable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
+	if (ret)
+		goto err_power_put;
+
+	ret = ipa_endpoint_enable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_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(ipa->name_map[IPA_ENDPOINT_AP_MODEM_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->pdev->dev;
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0)
+		goto out_power_put;
+
+	netif_stop_queue(netdev);
+
+	ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
+	ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
+out_power_put:
+	pm_runtime_mark_last_busy(dev);
+	(void)pm_runtime_put_autosuspend(dev);
+
+	return 0;
+}
+
+/** ipa_start_xmit() - Transmits an skb.
+ * @skb: skb to be transmitted
+ * @dev: network device
+ *
+ * Return codes:
+ * NETDEV_TX_OK: Success
+ * NETDEV_TX_BUSY: Error while transmitting the skb. Try again 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 */
+	dev = &ipa->pdev->dev;
+	ret = pm_runtime_get(dev);
+	if (ret < 1) {
+		/* If a resume won't happen, just drop the packet */
+		if (ret < 0 && ret != -EINPROGRESS) {
+			ipa_power_modem_queue_active(ipa);
+			pm_runtime_put_noidle(dev);
+			goto err_drop_skb;
+		}
+
+		/* No power (yet).  Stop the network stack from transmitting
+		 * until we're resumed; ipa_modem_resume() arranges for the
+		 * TX queue to be started again.
+		 */
+		ipa_power_modem_queue_stop(ipa);
+
+		pm_runtime_put_noidle(dev);
+
+		return NETDEV_TX_BUSY;
+	}
+
+	ipa_power_modem_queue_active(ipa);
+
+	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 = netdev_priv(netdev);
+	struct ipa *ipa = priv->ipa;
+
+	if (!(netdev->flags & IFF_UP))
+		return;
+
+	ipa_endpoint_suspend_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
+	ipa_endpoint_suspend_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_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);
+
+	ipa_power_modem_queue_wake(priv->ipa);
+}
+
+/** 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 = netdev_priv(netdev);
+	struct ipa *ipa = priv->ipa;
+
+	if (!(netdev->flags & IFF_UP))
+		return;
+
+	ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
+	ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_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->pdev->dev);
+	priv = netdev_priv(netdev);
+	priv->ipa = ipa;
+	INIT_WORK(&priv->work, ipa_modem_wake_queue_work);
+	ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = netdev;
+	ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = netdev;
+	ipa->modem_netdev = netdev;
+
+	ret = register_netdev(netdev);
+	if (ret) {
+		ipa->modem_netdev = NULL;
+		ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = NULL;
+		ipa->name_map[IPA_ENDPOINT_AP_MODEM_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;
+		ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = NULL;
+		ipa->name_map[IPA_ENDPOINT_AP_MODEM_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->pdev->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->pdev->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->pdev->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));
+}