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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qcom_glink_ssr.c (4155B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (c) 2014-2017, The Linux Foundation. All rights reserved.
      4 * Copyright (c) 2017, Linaro Ltd.
      5 */
      6
      7#include <linux/completion.h>
      8#include <linux/module.h>
      9#include <linux/notifier.h>
     10#include <linux/rpmsg.h>
     11#include <linux/rpmsg/qcom_glink.h>
     12#include <linux/remoteproc/qcom_rproc.h>
     13
     14/**
     15 * struct do_cleanup_msg - The data structure for an SSR do_cleanup message
     16 * @version:	The G-Link SSR protocol version
     17 * @command:	The G-Link SSR command - do_cleanup
     18 * @seq_num:	Sequence number
     19 * @name_len:	Length of the name of the subsystem being restarted
     20 * @name:	G-Link edge name of the subsystem being restarted
     21 */
     22struct do_cleanup_msg {
     23	__le32 version;
     24	__le32 command;
     25	__le32 seq_num;
     26	__le32 name_len;
     27	char name[32];
     28};
     29
     30/**
     31 * struct cleanup_done_msg - The data structure for an SSR cleanup_done message
     32 * @version:	The G-Link SSR protocol version
     33 * @response:	The G-Link SSR response to a do_cleanup command, cleanup_done
     34 * @seq_num:	Sequence number
     35 */
     36struct cleanup_done_msg {
     37	__le32 version;
     38	__le32 response;
     39	__le32 seq_num;
     40};
     41
     42/**
     43 * G-Link SSR protocol commands
     44 */
     45#define GLINK_SSR_DO_CLEANUP	0
     46#define GLINK_SSR_CLEANUP_DONE	1
     47
     48struct glink_ssr {
     49	struct device *dev;
     50	struct rpmsg_endpoint *ept;
     51
     52	struct notifier_block nb;
     53
     54	u32 seq_num;
     55	struct completion completion;
     56};
     57
     58/* Notifier list for all registered glink_ssr instances */
     59static BLOCKING_NOTIFIER_HEAD(ssr_notifiers);
     60
     61/**
     62 * qcom_glink_ssr_notify() - notify GLINK SSR about stopped remoteproc
     63 * @ssr_name:	name of the remoteproc that has been stopped
     64 */
     65void qcom_glink_ssr_notify(const char *ssr_name)
     66{
     67	blocking_notifier_call_chain(&ssr_notifiers, 0, (void *)ssr_name);
     68}
     69EXPORT_SYMBOL_GPL(qcom_glink_ssr_notify);
     70
     71static int qcom_glink_ssr_callback(struct rpmsg_device *rpdev,
     72				   void *data, int len, void *priv, u32 addr)
     73{
     74	struct cleanup_done_msg *msg = data;
     75	struct glink_ssr *ssr = dev_get_drvdata(&rpdev->dev);
     76
     77	if (len < sizeof(*msg)) {
     78		dev_err(ssr->dev, "message too short\n");
     79		return -EINVAL;
     80	}
     81
     82	if (le32_to_cpu(msg->version) != 0)
     83		return -EINVAL;
     84
     85	if (le32_to_cpu(msg->response) != GLINK_SSR_CLEANUP_DONE)
     86		return 0;
     87
     88	if (le32_to_cpu(msg->seq_num) != ssr->seq_num) {
     89		dev_err(ssr->dev, "invalid sequence number of response\n");
     90		return -EINVAL;
     91	}
     92
     93	complete(&ssr->completion);
     94
     95	return 0;
     96}
     97
     98static int qcom_glink_ssr_notifier_call(struct notifier_block *nb,
     99					unsigned long event,
    100					void *data)
    101{
    102	struct glink_ssr *ssr = container_of(nb, struct glink_ssr, nb);
    103	struct do_cleanup_msg msg;
    104	char *ssr_name = data;
    105	int ret;
    106
    107	ssr->seq_num++;
    108	reinit_completion(&ssr->completion);
    109
    110	memset(&msg, 0, sizeof(msg));
    111	msg.command = cpu_to_le32(GLINK_SSR_DO_CLEANUP);
    112	msg.seq_num = cpu_to_le32(ssr->seq_num);
    113	msg.name_len = cpu_to_le32(strlen(ssr_name));
    114	strlcpy(msg.name, ssr_name, sizeof(msg.name));
    115
    116	ret = rpmsg_send(ssr->ept, &msg, sizeof(msg));
    117	if (ret < 0)
    118		dev_err(ssr->dev, "failed to send cleanup message\n");
    119
    120	ret = wait_for_completion_timeout(&ssr->completion, HZ);
    121	if (!ret)
    122		dev_err(ssr->dev, "timeout waiting for cleanup done message\n");
    123
    124	return NOTIFY_DONE;
    125}
    126
    127static int qcom_glink_ssr_probe(struct rpmsg_device *rpdev)
    128{
    129	struct glink_ssr *ssr;
    130
    131	ssr = devm_kzalloc(&rpdev->dev, sizeof(*ssr), GFP_KERNEL);
    132	if (!ssr)
    133		return -ENOMEM;
    134
    135	init_completion(&ssr->completion);
    136
    137	ssr->dev = &rpdev->dev;
    138	ssr->ept = rpdev->ept;
    139	ssr->nb.notifier_call = qcom_glink_ssr_notifier_call;
    140
    141	dev_set_drvdata(&rpdev->dev, ssr);
    142
    143	return blocking_notifier_chain_register(&ssr_notifiers, &ssr->nb);
    144}
    145
    146static void qcom_glink_ssr_remove(struct rpmsg_device *rpdev)
    147{
    148	struct glink_ssr *ssr = dev_get_drvdata(&rpdev->dev);
    149
    150	blocking_notifier_chain_unregister(&ssr_notifiers, &ssr->nb);
    151}
    152
    153static const struct rpmsg_device_id qcom_glink_ssr_match[] = {
    154	{ "glink_ssr" },
    155	{}
    156};
    157
    158static struct rpmsg_driver qcom_glink_ssr_driver = {
    159	.probe = qcom_glink_ssr_probe,
    160	.remove = qcom_glink_ssr_remove,
    161	.callback = qcom_glink_ssr_callback,
    162	.id_table = qcom_glink_ssr_match,
    163	.drv = {
    164		.name = "qcom_glink_ssr",
    165	},
    166};
    167module_rpmsg_driver(qcom_glink_ssr_driver);