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(nh: &ssr_notifiers, val: 0, v: (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(dev: &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(x: &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 strscpy(msg.name, ssr_name, sizeof(msg.name));
115
116 ret = rpmsg_send(ept: ssr->ept, data: &msg, len: sizeof(msg));
117 if (ret < 0)
118 dev_err(ssr->dev, "failed to send cleanup message\n");
119
120 ret = wait_for_completion_timeout(x: &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(dev: &rpdev->dev, size: sizeof(*ssr), GFP_KERNEL);
132 if (!ssr)
133 return -ENOMEM;
134
135 init_completion(x: &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(dev: &rpdev->dev, data: ssr);
142
143 return blocking_notifier_chain_register(nh: &ssr_notifiers, nb: &ssr->nb);
144}
145
146static void qcom_glink_ssr_remove(struct rpmsg_device *rpdev)
147{
148 struct glink_ssr *ssr = dev_get_drvdata(dev: &rpdev->dev);
149
150 blocking_notifier_chain_unregister(nh: &ssr_notifiers, nb: &ssr->nb);
151}
152
153static const struct rpmsg_device_id qcom_glink_ssr_match[] = {
154 { "glink_ssr" },
155 {}
156};
157MODULE_DEVICE_TABLE(rpmsg, qcom_glink_ssr_match);
158
159static struct rpmsg_driver qcom_glink_ssr_driver = {
160 .probe = qcom_glink_ssr_probe,
161 .remove = qcom_glink_ssr_remove,
162 .callback = qcom_glink_ssr_callback,
163 .id_table = qcom_glink_ssr_match,
164 .drv = {
165 .name = "qcom_glink_ssr",
166 },
167};
168module_rpmsg_driver(qcom_glink_ssr_driver);
169

source code of linux/drivers/rpmsg/qcom_glink_ssr.c