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 | */ |
22 | struct 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 | */ |
36 | struct 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 | |
48 | struct 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 */ |
59 | static 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 | */ |
65 | void qcom_glink_ssr_notify(const char *ssr_name) |
66 | { |
67 | blocking_notifier_call_chain(nh: &ssr_notifiers, val: 0, v: (void *)ssr_name); |
68 | } |
69 | EXPORT_SYMBOL_GPL(qcom_glink_ssr_notify); |
70 | |
71 | static 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 | |
98 | static 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(p: msg.name, q: ssr_name, size: 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 | |
127 | static 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 | |
146 | static 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 | |
153 | static const struct rpmsg_device_id qcom_glink_ssr_match[] = { |
154 | { "glink_ssr" }, |
155 | {} |
156 | }; |
157 | |
158 | static 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 | }; |
167 | module_rpmsg_driver(qcom_glink_ssr_driver); |
168 | |