Commit c4d77d5f authored by Bjorn Andersson's avatar Bjorn Andersson

soc: qcom: GLINK SSR notifier

This driver register as a subsystem restart notifier and will send out
notifications to remote processors that has opened the "glink_ssr" GLINK
channel.

This mechanism is used to signal any GLINK participants that a 3rd party
is gone and that the communication state has to be reset; i.e. that read
and write pointers of the GLINK FIFOs are stale.
Acked-by: default avatarAndy Gross <andy.gross@linaro.org>
Signed-off-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
parent 1e140df0
#
# QCOM Soc drivers
#
config QCOM_GLINK_SSR
tristate "Qualcomm Glink SSR driver"
depends on RPMSG
depends on QCOM_RPROC_COMMON
help
Say y here to enable GLINK SSR support. The GLINK SSR driver
implements the SSR protocol for notifying the remote processor about
neighboring subsystems going up or down.
config QCOM_GSBI
tristate "QCOM General Serial Bus Interface"
depends on ARCH_QCOM
......
obj-$(CONFIG_QCOM_GLINK_SSR) += glink_ssr.o
obj-$(CONFIG_QCOM_GSBI) += qcom_gsbi.o
obj-$(CONFIG_QCOM_MDT_LOADER) += mdt_loader.o
obj-$(CONFIG_QCOM_PM) += spm.o
......
/*
* Copyright (c) 2014-2017, The Linux Foundation. All rights reserved.
* Copyright (c) 2017, Linaro Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/completion.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/rpmsg.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;
};
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_notify(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_notify;
dev_set_drvdata(&rpdev->dev, ssr);
return qcom_register_ssr_notifier(&ssr->nb);
}
static void qcom_glink_ssr_remove(struct rpmsg_device *rpdev)
{
struct glink_ssr *ssr = dev_get_drvdata(&rpdev->dev);
qcom_unregister_ssr_notifier(&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);
MODULE_ALIAS("rpmsg:glink_ssr");
MODULE_DESCRIPTION("Qualcomm GLINK SSR notifier");
MODULE_LICENSE("GPL v2");
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