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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rpmsg_wwan_ctrl.c (4292B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/* Copyright (c) 2021, Stephan Gerhold <stephan@gerhold.net> */
      3#include <linux/kernel.h>
      4#include <linux/mod_devicetable.h>
      5#include <linux/module.h>
      6#include <linux/platform_device.h>
      7#include <linux/rpmsg.h>
      8#include <linux/wwan.h>
      9
     10struct rpmsg_wwan_dev {
     11	/* Lower level is a rpmsg dev, upper level is a wwan port */
     12	struct rpmsg_device *rpdev;
     13	struct wwan_port *wwan_port;
     14	struct rpmsg_endpoint *ept;
     15};
     16
     17static int rpmsg_wwan_ctrl_callback(struct rpmsg_device *rpdev,
     18				    void *buf, int len, void *priv, u32 src)
     19{
     20	struct rpmsg_wwan_dev *rpwwan = priv;
     21	struct sk_buff *skb;
     22
     23	skb = alloc_skb(len, GFP_ATOMIC);
     24	if (!skb)
     25		return -ENOMEM;
     26
     27	skb_put_data(skb, buf, len);
     28	wwan_port_rx(rpwwan->wwan_port, skb);
     29	return 0;
     30}
     31
     32static int rpmsg_wwan_ctrl_start(struct wwan_port *port)
     33{
     34	struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
     35	struct rpmsg_channel_info chinfo = {
     36		.src = rpwwan->rpdev->src,
     37		.dst = RPMSG_ADDR_ANY,
     38	};
     39
     40	strncpy(chinfo.name, rpwwan->rpdev->id.name, RPMSG_NAME_SIZE);
     41	rpwwan->ept = rpmsg_create_ept(rpwwan->rpdev, rpmsg_wwan_ctrl_callback,
     42				       rpwwan, chinfo);
     43	if (!rpwwan->ept)
     44		return -EREMOTEIO;
     45
     46	return 0;
     47}
     48
     49static void rpmsg_wwan_ctrl_stop(struct wwan_port *port)
     50{
     51	struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
     52
     53	rpmsg_destroy_ept(rpwwan->ept);
     54	rpwwan->ept = NULL;
     55}
     56
     57static int rpmsg_wwan_ctrl_tx(struct wwan_port *port, struct sk_buff *skb)
     58{
     59	struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
     60	int ret;
     61
     62	ret = rpmsg_trysend(rpwwan->ept, skb->data, skb->len);
     63	if (ret)
     64		return ret;
     65
     66	consume_skb(skb);
     67	return 0;
     68}
     69
     70static int rpmsg_wwan_ctrl_tx_blocking(struct wwan_port *port, struct sk_buff *skb)
     71{
     72	struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
     73	int ret;
     74
     75	ret = rpmsg_send(rpwwan->ept, skb->data, skb->len);
     76	if (ret)
     77		return ret;
     78
     79	consume_skb(skb);
     80	return 0;
     81}
     82
     83static __poll_t rpmsg_wwan_ctrl_tx_poll(struct wwan_port *port,
     84					struct file *filp, poll_table *wait)
     85{
     86	struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
     87
     88	return rpmsg_poll(rpwwan->ept, filp, wait);
     89}
     90
     91static const struct wwan_port_ops rpmsg_wwan_pops = {
     92	.start = rpmsg_wwan_ctrl_start,
     93	.stop = rpmsg_wwan_ctrl_stop,
     94	.tx = rpmsg_wwan_ctrl_tx,
     95	.tx_blocking = rpmsg_wwan_ctrl_tx_blocking,
     96	.tx_poll = rpmsg_wwan_ctrl_tx_poll,
     97};
     98
     99static struct device *rpmsg_wwan_find_parent(struct device *dev)
    100{
    101	/* Select first platform device as parent for the WWAN ports.
    102	 * On Qualcomm platforms this is usually the platform device that
    103	 * represents the modem remote processor. This might need to be
    104	 * adjusted when adding device IDs for other platforms.
    105	 */
    106	for (dev = dev->parent; dev; dev = dev->parent) {
    107		if (dev_is_platform(dev))
    108			return dev;
    109	}
    110	return NULL;
    111}
    112
    113static int rpmsg_wwan_ctrl_probe(struct rpmsg_device *rpdev)
    114{
    115	struct rpmsg_wwan_dev *rpwwan;
    116	struct wwan_port *port;
    117	struct device *parent;
    118
    119	parent = rpmsg_wwan_find_parent(&rpdev->dev);
    120	if (!parent)
    121		return -ENODEV;
    122
    123	rpwwan = devm_kzalloc(&rpdev->dev, sizeof(*rpwwan), GFP_KERNEL);
    124	if (!rpwwan)
    125		return -ENOMEM;
    126
    127	rpwwan->rpdev = rpdev;
    128	dev_set_drvdata(&rpdev->dev, rpwwan);
    129
    130	/* Register as a wwan port, id.driver_data contains wwan port type */
    131	port = wwan_create_port(parent, rpdev->id.driver_data,
    132				&rpmsg_wwan_pops, rpwwan);
    133	if (IS_ERR(port))
    134		return PTR_ERR(port);
    135
    136	rpwwan->wwan_port = port;
    137
    138	return 0;
    139};
    140
    141static void rpmsg_wwan_ctrl_remove(struct rpmsg_device *rpdev)
    142{
    143	struct rpmsg_wwan_dev *rpwwan = dev_get_drvdata(&rpdev->dev);
    144
    145	wwan_remove_port(rpwwan->wwan_port);
    146}
    147
    148static const struct rpmsg_device_id rpmsg_wwan_ctrl_id_table[] = {
    149	/* RPMSG channels for Qualcomm SoCs with integrated modem */
    150	{ .name = "DATA5_CNTL", .driver_data = WWAN_PORT_QMI },
    151	{ .name = "DATA4", .driver_data = WWAN_PORT_AT },
    152	{},
    153};
    154MODULE_DEVICE_TABLE(rpmsg, rpmsg_wwan_ctrl_id_table);
    155
    156static struct rpmsg_driver rpmsg_wwan_ctrl_driver = {
    157	.drv.name = "rpmsg_wwan_ctrl",
    158	.id_table = rpmsg_wwan_ctrl_id_table,
    159	.probe = rpmsg_wwan_ctrl_probe,
    160	.remove = rpmsg_wwan_ctrl_remove,
    161};
    162module_rpmsg_driver(rpmsg_wwan_ctrl_driver);
    163
    164MODULE_LICENSE("GPL v2");
    165MODULE_DESCRIPTION("RPMSG WWAN CTRL Driver");
    166MODULE_AUTHOR("Stephan Gerhold <stephan@gerhold.net>");