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1// SPDX-License-Identifier: GPL-2.0-only2/*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 message16 * @version: The G-Link SSR protocol version17 * @command: The G-Link SSR command - do_cleanup18 * @seq_num: Sequence number19 * @name_len: Length of the name of the subsystem being restarted20 * @name: G-Link edge name of the subsystem being restarted21 */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 message32 * @version: The G-Link SSR protocol version33 * @response: The G-Link SSR response to a do_cleanup command, cleanup_done34 * @seq_num: Sequence number35 */36struct cleanup_done_msg {37 __le32 version;38 __le32 response;39 __le32 seq_num;40};41 42/*43 * G-Link SSR protocol commands44 */45#define GLINK_SSR_DO_CLEANUP 046#define GLINK_SSR_CLEANUP_DONE 147 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 remoteproc63 * @ssr_name: name of the remoteproc that has been stopped64 */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 strscpy(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};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