cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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mhi.c (3028B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
      4 */
      5
      6#include <linux/mhi.h>
      7#include <linux/mod_devicetable.h>
      8#include <linux/module.h>
      9#include <linux/skbuff.h>
     10#include <net/sock.h>
     11
     12#include "qrtr.h"
     13
     14struct qrtr_mhi_dev {
     15	struct qrtr_endpoint ep;
     16	struct mhi_device *mhi_dev;
     17	struct device *dev;
     18};
     19
     20/* From MHI to QRTR */
     21static void qcom_mhi_qrtr_dl_callback(struct mhi_device *mhi_dev,
     22				      struct mhi_result *mhi_res)
     23{
     24	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
     25	int rc;
     26
     27	if (!qdev || mhi_res->transaction_status)
     28		return;
     29
     30	rc = qrtr_endpoint_post(&qdev->ep, mhi_res->buf_addr,
     31				mhi_res->bytes_xferd);
     32	if (rc == -EINVAL)
     33		dev_err(qdev->dev, "invalid ipcrouter packet\n");
     34}
     35
     36/* From QRTR to MHI */
     37static void qcom_mhi_qrtr_ul_callback(struct mhi_device *mhi_dev,
     38				      struct mhi_result *mhi_res)
     39{
     40	struct sk_buff *skb = mhi_res->buf_addr;
     41
     42	if (skb->sk)
     43		sock_put(skb->sk);
     44	consume_skb(skb);
     45}
     46
     47/* Send data over MHI */
     48static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
     49{
     50	struct qrtr_mhi_dev *qdev = container_of(ep, struct qrtr_mhi_dev, ep);
     51	int rc;
     52
     53	if (skb->sk)
     54		sock_hold(skb->sk);
     55
     56	rc = skb_linearize(skb);
     57	if (rc)
     58		goto free_skb;
     59
     60	rc = mhi_queue_skb(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len,
     61			   MHI_EOT);
     62	if (rc)
     63		goto free_skb;
     64
     65	return rc;
     66
     67free_skb:
     68	if (skb->sk)
     69		sock_put(skb->sk);
     70	kfree_skb(skb);
     71
     72	return rc;
     73}
     74
     75static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
     76			       const struct mhi_device_id *id)
     77{
     78	struct qrtr_mhi_dev *qdev;
     79	int rc;
     80
     81	/* start channels */
     82	rc = mhi_prepare_for_transfer_autoqueue(mhi_dev);
     83	if (rc)
     84		return rc;
     85
     86	qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL);
     87	if (!qdev)
     88		return -ENOMEM;
     89
     90	qdev->mhi_dev = mhi_dev;
     91	qdev->dev = &mhi_dev->dev;
     92	qdev->ep.xmit = qcom_mhi_qrtr_send;
     93
     94	dev_set_drvdata(&mhi_dev->dev, qdev);
     95	rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
     96	if (rc)
     97		return rc;
     98
     99	dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");
    100
    101	return 0;
    102}
    103
    104static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev)
    105{
    106	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
    107
    108	qrtr_endpoint_unregister(&qdev->ep);
    109	mhi_unprepare_from_transfer(mhi_dev);
    110	dev_set_drvdata(&mhi_dev->dev, NULL);
    111}
    112
    113static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
    114	{ .chan = "IPCR" },
    115	{}
    116};
    117MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
    118
    119static struct mhi_driver qcom_mhi_qrtr_driver = {
    120	.probe = qcom_mhi_qrtr_probe,
    121	.remove = qcom_mhi_qrtr_remove,
    122	.dl_xfer_cb = qcom_mhi_qrtr_dl_callback,
    123	.ul_xfer_cb = qcom_mhi_qrtr_ul_callback,
    124	.id_table = qcom_mhi_qrtr_id_table,
    125	.driver = {
    126		.name = "qcom_mhi_qrtr",
    127	},
    128};
    129
    130module_mhi_driver(qcom_mhi_qrtr_driver);
    131
    132MODULE_AUTHOR("Chris Lew <clew@codeaurora.org>");
    133MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
    134MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
    135MODULE_LICENSE("GPL v2");