summaryrefslogtreecommitdiff
path: root/drivers/rpmsg/qcom_glink_ssr.c
blob: e71d3716c55c5c1ca9916c8e0ad2ab84ca8e7b6b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2014-2017, The Linux Foundation. All rights reserved.
 * Copyright (c) 2017, Linaro Ltd.
 */

#include <linux/completion.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/rpmsg.h>
#include <linux/rpmsg/qcom_glink.h>
#include <linux/remoteproc/qcom_rproc.h>

/**
 * struct do_cleanup_msg - The data structure for an SSR do_cleanup message
 * @version:	The G-Link SSR protocol version
 * @command:	The G-Link SSR command - do_cleanup
 * @seq_num:	Sequence number
 * @name_len:	Length of the name of the subsystem being restarted
 * @name:	G-Link edge name of the subsystem being restarted
 */
struct do_cleanup_msg {
	__le32 version;
	__le32 command;
	__le32 seq_num;
	__le32 name_len;
	char name[32];
};

/**
 * struct cleanup_done_msg - The data structure for an SSR cleanup_done message
 * @version:	The G-Link SSR protocol version
 * @response:	The G-Link SSR response to a do_cleanup command, cleanup_done
 * @seq_num:	Sequence number
 */
struct cleanup_done_msg {
	__le32 version;
	__le32 response;
	__le32 seq_num;
};

/*
 * G-Link SSR protocol commands
 */
#define GLINK_SSR_DO_CLEANUP	0
#define GLINK_SSR_CLEANUP_DONE	1

struct glink_ssr {
	struct device *dev;
	struct rpmsg_endpoint *ept;

	struct notifier_block nb;

	u32 seq_num;
	struct completion completion;
};

/* Notifier list for all registered glink_ssr instances */
static BLOCKING_NOTIFIER_HEAD(ssr_notifiers);

/**
 * qcom_glink_ssr_notify() - notify GLINK SSR about stopped remoteproc
 * @ssr_name:	name of the remoteproc that has been stopped
 */
void qcom_glink_ssr_notify(const char *ssr_name)
{
	blocking_notifier_call_chain(&ssr_notifiers, 0, (void *)ssr_name);
}
EXPORT_SYMBOL_GPL(qcom_glink_ssr_notify);

static int qcom_glink_ssr_callback(struct rpmsg_device *rpdev,
				   void *data, int len, void *priv, u32 addr)
{
	struct cleanup_done_msg *msg = data;
	struct glink_ssr *ssr = dev_get_drvdata(&rpdev->dev);

	if (len < sizeof(*msg)) {
		dev_err(ssr->dev, "message too short\n");
		return -EINVAL;
	}

	if (le32_to_cpu(msg->version) != 0)
		return -EINVAL;

	if (le32_to_cpu(msg->response) != GLINK_SSR_CLEANUP_DONE)
		return 0;

	if (le32_to_cpu(msg->seq_num) != ssr->seq_num) {
		dev_err(ssr->dev, "invalid sequence number of response\n");
		return -EINVAL;
	}

	complete(&ssr->completion);

	return 0;
}

static int qcom_glink_ssr_notifier_call(struct notifier_block *nb,
					unsigned long event,
					void *data)
{
	struct glink_ssr *ssr = container_of(nb, struct glink_ssr, nb);
	struct do_cleanup_msg msg;
	char *ssr_name = data;
	int ret;

	ssr->seq_num++;
	reinit_completion(&ssr->completion);

	memset(&msg, 0, sizeof(msg));
	msg.command = cpu_to_le32(GLINK_SSR_DO_CLEANUP);
	msg.seq_num = cpu_to_le32(ssr->seq_num);
	msg.name_len = cpu_to_le32(strlen(ssr_name));
	strscpy(msg.name, ssr_name, sizeof(msg.name));

	ret = rpmsg_send(ssr->ept, &msg, sizeof(msg));
	if (ret < 0)
		dev_err(ssr->dev, "failed to send cleanup message\n");

	ret = wait_for_completion_timeout(&ssr->completion, HZ);
	if (!ret)
		dev_err(ssr->dev, "timeout waiting for cleanup done message\n");

	return NOTIFY_DONE;
}

static int qcom_glink_ssr_probe(struct rpmsg_device *rpdev)
{
	struct glink_ssr *ssr;

	ssr = devm_kzalloc(&rpdev->dev, sizeof(*ssr), GFP_KERNEL);
	if (!ssr)
		return -ENOMEM;

	init_completion(&ssr->completion);

	ssr->dev = &rpdev->dev;
	ssr->ept = rpdev->ept;
	ssr->nb.notifier_call = qcom_glink_ssr_notifier_call;

	dev_set_drvdata(&rpdev->dev, ssr);

	return blocking_notifier_chain_register(&ssr_notifiers, &ssr->nb);
}

static void qcom_glink_ssr_remove(struct rpmsg_device *rpdev)
{
	struct glink_ssr *ssr = dev_get_drvdata(&rpdev->dev);

	blocking_notifier_chain_unregister(&ssr_notifiers, &ssr->nb);
}

static const struct rpmsg_device_id qcom_glink_ssr_match[] = {
	{ "glink_ssr" },
	{}
};
MODULE_DEVICE_TABLE(rpmsg, qcom_glink_ssr_match);

static struct rpmsg_driver qcom_glink_ssr_driver = {
	.probe = qcom_glink_ssr_probe,
	.remove = qcom_glink_ssr_remove,
	.callback = qcom_glink_ssr_callback,
	.id_table = qcom_glink_ssr_match,
	.drv = {
		.name = "qcom_glink_ssr",
	},
};
module_rpmsg_driver(qcom_glink_ssr_driver);