From c4d77d5fcd8baefb358ae921b940e9bbd09a751e Mon Sep 17 00:00:00 2001 From: Bjorn Andersson Date: Mon, 24 Jul 2017 22:56:44 -0700 Subject: [PATCH] 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: Andy Gross Signed-off-by: Bjorn Andersson --- drivers/soc/qcom/Kconfig | 9 ++ drivers/soc/qcom/Makefile | 1 + drivers/soc/qcom/glink_ssr.c | 164 +++++++++++++++++++++++++++++++++++ 3 files changed, 174 insertions(+) create mode 100644 drivers/soc/qcom/glink_ssr.c diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig index 9fca977ef18d..d0fc331972d2 100644 --- a/drivers/soc/qcom/Kconfig +++ b/drivers/soc/qcom/Kconfig @@ -1,6 +1,15 @@ # # 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 diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile index 414f0de274fa..f151de41eb93 100644 --- a/drivers/soc/qcom/Makefile +++ b/drivers/soc/qcom/Makefile @@ -1,3 +1,4 @@ +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 diff --git a/drivers/soc/qcom/glink_ssr.c b/drivers/soc/qcom/glink_ssr.c new file mode 100644 index 000000000000..19c7399eddb5 --- /dev/null +++ b/drivers/soc/qcom/glink_ssr.c @@ -0,0 +1,164 @@ +/* + * 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 +#include +#include +#include +#include + +/** + * 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"); -- 2.20.1