linux/drivers/rpmsg/qcom_glink_ssr.c

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// 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));
strlcpy(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" },
{}
};
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);