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