diff --git a/net/qrtr/Kconfig b/net/qrtr/Kconfig index e0055e4dee85..46ddacba3b3f 100644 --- a/net/qrtr/Kconfig +++ b/net/qrtr/Kconfig @@ -40,4 +40,13 @@ config QRTR_TUN implement endpoints of QRTR, for purpose of tunneling data to other hosts or testing purposes. +config QRTR_MHI + tristate "MHI IPC Router channels" + depends on MHI_BUS || (COMPILE_TEST && MHI_BUS=n) + help + Say Y here to support MHI based ipcrouter channels. MHI is the + transport used for external modem connections for IPC Router. The + MHI transport fakes synchronous sends by waiting for the uplink + callback from the MHI framework before returing to qrtr core. + endif # QRTR diff --git a/net/qrtr/Makefile b/net/qrtr/Makefile index 1c6d6c120fb7..3dc0a7c9d455 100644 --- a/net/qrtr/Makefile +++ b/net/qrtr/Makefile @@ -5,3 +5,5 @@ obj-$(CONFIG_QRTR_SMD) += qrtr-smd.o qrtr-smd-y := smd.o obj-$(CONFIG_QRTR_TUN) += qrtr-tun.o qrtr-tun-y := tun.o +obj-$(CONFIG_QRTR_MHI) += qrtr-mhi.o +qrtr-mhi-y := mhi.o diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c new file mode 100644 index 000000000000..ab21357fe1b0 --- /dev/null +++ b/net/qrtr/mhi.c @@ -0,0 +1,215 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2018-2020, The Linux Foundation. All rights reserved. */ + +#include +#include +#include +#include +#include +#include + +#include "qrtr.h" + +struct qrtr_mhi_dev { + struct qrtr_endpoint ep; + struct mhi_device *mhi_dev; + struct device *dev; + spinlock_t ul_lock; /* lock to protect ul_pkts */ + struct list_head ul_pkts; + atomic_t in_reset; +}; + +struct qrtr_mhi_pkt { + struct list_head node; + struct sk_buff *skb; + struct kref refcount; + struct completion done; +}; + +static void qrtr_mhi_pkt_release(struct kref *ref) +{ + struct qrtr_mhi_pkt *pkt = container_of(ref, struct qrtr_mhi_pkt, + refcount); + struct sock *sk = pkt->skb->sk; + + consume_skb(pkt->skb); + if (sk) + sock_put(sk); + kfree(pkt); +} + +/* from mhi to qrtr */ +static void qcom_mhi_qrtr_dl_callback(struct mhi_device *mhi_dev, + struct mhi_result *mhi_res) +{ + struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev); + int rc; + + if (!qdev || mhi_res->transaction_status) + return; + + rc = qrtr_endpoint_post(&qdev->ep, mhi_res->buf_addr, + mhi_res->bytes_xferd); + if (rc == -EINVAL) + dev_err(qdev->dev, "invalid ipcrouter packet\n"); +} + +/* from mhi to qrtr */ +static void qcom_mhi_qrtr_ul_callback(struct mhi_device *mhi_dev, + struct mhi_result *mhi_res) +{ + struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev); + struct qrtr_mhi_pkt *pkt; + unsigned long flags; + + spin_lock_irqsave(&qdev->ul_lock, flags); + if (list_empty(&qdev->ul_pkts)) { + spin_unlock_irqrestore(&qdev->ul_lock, flags); + dev_err(qdev->dev, "ul_pkt list is empty\n"); + return; + } + pkt = list_first_entry(&qdev->ul_pkts, struct qrtr_mhi_pkt, node); + list_del(&pkt->node); + complete_all(&pkt->done); + + kref_put(&pkt->refcount, qrtr_mhi_pkt_release); + spin_unlock_irqrestore(&qdev->ul_lock, flags); +} + +/* fatal error */ +static void qcom_mhi_qrtr_status_callback(struct mhi_device *mhi_dev, + enum MHI_CB mhi_cb) +{ + struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev); + struct qrtr_mhi_pkt *pkt; + unsigned long flags; + + if (mhi_cb != MHI_CB_FATAL_ERROR) + return; + + atomic_inc(&qdev->in_reset); + spin_lock_irqsave(&qdev->ul_lock, flags); + list_for_each_entry(pkt, &qdev->ul_pkts, node) + complete_all(&pkt->done); + spin_unlock_irqrestore(&qdev->ul_lock, flags); +} + +/* from qrtr to mhi */ +static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb) +{ + struct qrtr_mhi_dev *qdev = container_of(ep, struct qrtr_mhi_dev, ep); + struct qrtr_mhi_pkt *pkt; + int rc; + + rc = skb_linearize(skb); + if (rc) { + kfree_skb(skb); + return rc; + } + + pkt = kzalloc(sizeof(*pkt), GFP_KERNEL); + if (!pkt) { + kfree_skb(skb); + return -ENOMEM; + } + + init_completion(&pkt->done); + kref_init(&pkt->refcount); + kref_get(&pkt->refcount); + pkt->skb = skb; + + spin_lock_bh(&qdev->ul_lock); + list_add_tail(&pkt->node, &qdev->ul_pkts); + rc = mhi_queue_transfer(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len, + MHI_EOT); + if (rc) { + list_del(&pkt->node); + kfree_skb(skb); + kfree(pkt); + spin_unlock_bh(&qdev->ul_lock); + return rc; + } + spin_unlock_bh(&qdev->ul_lock); + if (skb->sk) + sock_hold(skb->sk); + + rc = wait_for_completion_interruptible_timeout(&pkt->done, HZ * 5); + if (atomic_read(&qdev->in_reset)) + rc = -ECONNRESET; + else if (rc == 0) + rc = -ETIMEDOUT; + else if (rc > 0) + rc = 0; + + kref_put(&pkt->refcount, qrtr_mhi_pkt_release); + return rc; +} + +static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev, + const struct mhi_device_id *id) +{ + struct qrtr_mhi_dev *qdev; + u32 net_id; + bool rt; + int rc; + + qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL); + if (!qdev) + return -ENOMEM; + + qdev->mhi_dev = mhi_dev; + qdev->dev = &mhi_dev->dev; + qdev->ep.xmit = qcom_mhi_qrtr_send; + atomic_set(&qdev->in_reset, 0); + + rc = of_property_read_u32(mhi_dev->dev.of_node, "qcom,net-id", &net_id); + if (rc < 0) + net_id = QRTR_EP_NET_ID_AUTO; + + rt = of_property_read_bool(mhi_dev->dev.of_node, "qcom,low-latency"); + + INIT_LIST_HEAD(&qdev->ul_pkts); + spin_lock_init(&qdev->ul_lock); + + rc = qrtr_endpoint_register(&qdev->ep, net_id, rt); + if (rc) + return rc; + + dev_set_drvdata(&mhi_dev->dev, qdev); + + dev_dbg(qdev->dev, "QTI MHI QRTR driver probed\n"); + + return 0; +} + +static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev) +{ + struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev); + + qrtr_endpoint_unregister(&qdev->ep); + dev_set_drvdata(&mhi_dev->dev, NULL); +} + +static const struct mhi_device_id qcom_mhi_qrtr_mhi_match[] = { + { .chan = "IPCR" }, + {} +}; + +static struct mhi_driver qcom_mhi_qrtr_driver = { + .probe = qcom_mhi_qrtr_probe, + .remove = qcom_mhi_qrtr_remove, + .dl_xfer_cb = qcom_mhi_qrtr_dl_callback, + .ul_xfer_cb = qcom_mhi_qrtr_ul_callback, + .status_cb = qcom_mhi_qrtr_status_callback, + .id_table = qcom_mhi_qrtr_mhi_match, + .driver = { + .name = "qcom_mhi_qrtr", + .owner = THIS_MODULE, + }, +}; + +module_driver(qcom_mhi_qrtr_driver, mhi_driver_register, + mhi_driver_unregister); + +MODULE_DESCRIPTION("QTI IPC-Router MHI interface driver"); +MODULE_LICENSE("GPL v2");