rpmsg: glink: Integrate glink_ssr in qcom_glink

In all but the very special case of a system with _only_ glink_rpm,
GLINK is dependent on glink_ssr, so move it to rpmsg and combine it with
qcom_glink_native in the new qcom_glink kernel module.

Acked-by: Chris Lew <clew@codeaurora.org>
Acked-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Link: https://lore.kernel.org/r/20200423003736.2027371-4-bjorn.andersson@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

3 files changed, 171 insertions, 4 deletions

diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
index a9108ff563dc..f96716893c2a 100644
--- a/drivers/rpmsg/Kconfig
+++ b/drivers/rpmsg/Kconfig
@@ -24,13 +24,13 @@ config RPMSG_MTK_SCP
 	  remote processors in MediaTek platforms.
 	  This use IPI and IPC to communicate with remote processors.
 
-config RPMSG_QCOM_GLINK_NATIVE
+config RPMSG_QCOM_GLINK
 	tristate
 	select RPMSG
 
 config RPMSG_QCOM_GLINK_RPM
 	tristate "Qualcomm RPM Glink driver"
-	select RPMSG_QCOM_GLINK_NATIVE
+	select RPMSG_QCOM_GLINK
 	depends on HAS_IOMEM
 	depends on MAILBOX
 	help
@@ -40,7 +40,7 @@ config RPMSG_QCOM_GLINK_RPM
 
 config RPMSG_QCOM_GLINK_SMEM
 	tristate "Qualcomm SMEM Glink driver"
-	select RPMSG_QCOM_GLINK_NATIVE
+	select RPMSG_QCOM_GLINK
 	depends on MAILBOX
 	depends on QCOM_SMEM
 	help
diff --git a/drivers/rpmsg/Makefile b/drivers/rpmsg/Makefile
index ae92a7fb08f6..ffe932ef6050 100644
--- a/drivers/rpmsg/Makefile
+++ b/drivers/rpmsg/Makefile
@@ -2,8 +2,9 @@
 obj-$(CONFIG_RPMSG)		+= rpmsg_core.o
 obj-$(CONFIG_RPMSG_CHAR)	+= rpmsg_char.o
 obj-$(CONFIG_RPMSG_MTK_SCP)	+= mtk_rpmsg.o
+qcom_glink-objs			:= qcom_glink_native.o qcom_glink_ssr.o
+obj-$(CONFIG_RPMSG_QCOM_GLINK) += qcom_glink.o
 obj-$(CONFIG_RPMSG_QCOM_GLINK_RPM) += qcom_glink_rpm.o
-obj-$(CONFIG_RPMSG_QCOM_GLINK_NATIVE) += qcom_glink_native.o
 obj-$(CONFIG_RPMSG_QCOM_GLINK_SMEM) += qcom_glink_smem.o
 obj-$(CONFIG_RPMSG_QCOM_SMD)	+= qcom_smd.o
 obj-$(CONFIG_RPMSG_VIRTIO)	+= virtio_rpmsg_bus.o
diff --git a/drivers/rpmsg/qcom_glink_ssr.c b/drivers/rpmsg/qcom_glink_ssr.c
new file mode 100644
index 000000000000..dcd1ce616974
--- /dev/null
+++ b/drivers/rpmsg/qcom_glink_ssr.c
@@ -0,0 +1,166 @@
+// 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/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);