coresight: Add driver to support for remote etm

Enables support for ETM trace collection on remote processor using
CoreSight framework. Enabling this will allow turning on ETM
tracing on remote processor via sysfs by configuring the required
CoreSight components.

Change-Id: I46b7c31eb81bd3b6623b71cf6c4811ba2d99d360
Signed-off-by: Tao Zhang <taozha@codeaurora.org>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>

drivers/hwtracing/coresight/Kconfig

@@ -196,6 +196,15 @@ config CORESIGHT_DUMMY
 	  other subsystem and use Linux drivers to configure rest of trace
 	  path.
 
+config CORESIGHT_REMOTE_ETM
+	tristate "Remote processor ETM trace support"
+	depends on QCOM_QMI_HELPERS
+	help
+	  Enables support for ETM trace collection on remote processor using
+	  CoreSight framework. Enabling this will allow turning on ETM
+	  tracing on remote processor via sysfs by configuring the required
+	  CoreSight components.
+
 config CORESIGHT_TRBE
 	tristate "Trace Buffer Extension (TRBE) driver"
 	depends on ARM64 && CORESIGHT_SOURCE_ETM4X

drivers/hwtracing/coresight/Makefile

@@ -28,3 +28,4 @@ obj-$(CONFIG_CORESIGHT_TRBE) += coresight-trbe.o
 coresight-cti-y := coresight-cti-core.o	coresight-cti-platform.o \
 		   coresight-cti-sysfs.o
 obj-$(CONFIG_CORESIGHT_DUMMY) += coresight-dummy.o
+obj-$(CONFIG_CORESIGHT_REMOTE_ETM) += coresight-remote-etm.o

drivers/hwtracing/coresight/coresight-remote-etm.c

@@ -0,0 +1,336 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/sysfs.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/coresight.h>
+#include "coresight-qmi.h"
+
+#define REMOTE_ETM_TRACE_ID_START	192
+
+#ifdef CONFIG_CORESIGHT_REMOTE_ETM_DEFAULT_ENABLE
+static int boot_enable = CONFIG_CORESIGHT_REMOTE_ETM_DEFAULT_ENABLE;
+#else
+static int boot_enable;
+#endif
+
+DEFINE_CORESIGHT_DEVLIST(remote_etm_devs, "remote-etm");
+
+struct remote_etm_drvdata {
+	struct device			*dev;
+	struct coresight_device		*csdev;
+	struct mutex			mutex;
+	struct qmi_handle		handle;
+	uint32_t			inst_id;
+	bool				enable;
+	int				traceid;
+	bool service_connected;
+	struct sockaddr_qrtr s_addr;
+};
+
+static int service_remote_etm_new_server(struct qmi_handle *qmi,
+		struct qmi_service *svc)
+{
+	struct remote_etm_drvdata *drvdata = container_of(qmi,
+					struct remote_etm_drvdata, handle);
+
+	drvdata->s_addr.sq_family = AF_QIPCRTR;
+	drvdata->s_addr.sq_node = svc->node;
+	drvdata->s_addr.sq_port = svc->port;
+	drvdata->service_connected = true;
+	dev_info(drvdata->dev,
+		"Connection established between QMI handle and %d service\n",
+		drvdata->inst_id);
+
+	return 0;
+}
+
+static void service_remote_etm_del_server(struct qmi_handle *qmi,
+		struct qmi_service *svc)
+{
+	struct remote_etm_drvdata *drvdata = container_of(qmi,
+					struct remote_etm_drvdata, handle);
+	drvdata->service_connected = false;
+	dev_info(drvdata->dev,
+		"Connection disconnected between QMI handle and %d service\n",
+		drvdata->inst_id);
+}
+
+static struct qmi_ops server_ops = {
+	.new_server = service_remote_etm_new_server,
+	.del_server = service_remote_etm_del_server,
+};
+
+static int remote_etm_enable(struct coresight_device *csdev,
+			     struct perf_event *event, u32 mode)
+{
+	struct remote_etm_drvdata *drvdata =
+		dev_get_drvdata(csdev->dev.parent);
+	struct coresight_set_etm_req_msg_v01 req;
+	struct coresight_set_etm_resp_msg_v01 resp = { { 0, 0 } };
+	struct qmi_txn txn;
+	int ret;
+
+	mutex_lock(&drvdata->mutex);
+
+	if (!drvdata->service_connected) {
+		dev_err(drvdata->dev, "QMI service not connected!\n");
+		ret = EINVAL;
+		goto err;
+	}
+	/*
+	 * The QMI handle may be NULL in the following scenarios:
+	 * 1. QMI service is not present
+	 * 2. QMI service is present but attempt to enable remote ETM is earlier
+	 *    than service is ready to handle request
+	 * 3. Connection between QMI client and QMI service failed
+	 *
+	 * Enable CoreSight without processing further QMI commands which
+	 * provides the option to enable remote ETM by other means.
+	 */
+	req.state = CORESIGHT_ETM_STATE_ENABLED_V01;
+
+	ret = qmi_txn_init(&drvdata->handle, &txn,
+			coresight_set_etm_resp_msg_v01_ei,
+			&resp);
+
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI tx init failed , ret:%d\n",
+				ret);
+		goto err;
+	}
+
+	ret = qmi_send_request(&drvdata->handle, &drvdata->s_addr,
+			&txn, CORESIGHT_QMI_SET_ETM_REQ_V01,
+			CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN,
+			coresight_set_etm_req_msg_v01_ei,
+			&req);
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI send ACK failed, ret:%d\n",
+				ret);
+		qmi_txn_cancel(&txn);
+		goto err;
+	}
+
+	ret = qmi_txn_wait(&txn, msecs_to_jiffies(TIMEOUT_MS));
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI qmi txn wait failed, ret:%d\n",
+				ret);
+		goto err;
+	}
+
+	/* Check the response */
+	if (resp.resp.result != QMI_RESULT_SUCCESS_V01)
+		dev_err(drvdata->dev, "QMI request failed 0x%x\n",
+				resp.resp.error);
+
+	drvdata->enable = true;
+	mutex_unlock(&drvdata->mutex);
+
+	dev_info(drvdata->dev, "Remote ETM tracing enabled for instance %d\n",
+				drvdata->inst_id);
+	return 0;
+err:
+	mutex_unlock(&drvdata->mutex);
+	return ret;
+}
+
+static void remote_etm_disable(struct coresight_device *csdev,
+			       struct perf_event *event)
+{
+	struct remote_etm_drvdata *drvdata =
+		 dev_get_drvdata(csdev->dev.parent);
+	struct coresight_set_etm_req_msg_v01 req;
+	struct coresight_set_etm_resp_msg_v01 resp = { { 0, 0 } };
+	struct qmi_txn txn;
+	int ret;
+
+	mutex_lock(&drvdata->mutex);
+	if (!drvdata->service_connected) {
+		dev_err(drvdata->dev, "QMI service not connected!\n");
+		goto err;
+	}
+
+	req.state = CORESIGHT_ETM_STATE_DISABLED_V01;
+
+	ret = qmi_txn_init(&drvdata->handle, &txn,
+			coresight_set_etm_resp_msg_v01_ei,
+			&resp);
+
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI tx init failed , ret:%d\n",
+				ret);
+		goto err;
+	}
+
+	ret = qmi_send_request(&drvdata->handle, &drvdata->s_addr,
+			&txn, CORESIGHT_QMI_SET_ETM_REQ_V01,
+			CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN,
+			coresight_set_etm_req_msg_v01_ei,
+			&req);
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI send req failed, ret:%d\n",
+				 ret);
+		qmi_txn_cancel(&txn);
+		goto err;
+	}
+
+	ret = qmi_txn_wait(&txn, msecs_to_jiffies(TIMEOUT_MS));
+	if (ret < 0) {
+		dev_err(drvdata->dev, "QMI qmi txn wait failed, ret:%d\n",
+				ret);
+		goto err;
+	}
+
+	/* Check the response */
+	if (resp.resp.result != QMI_RESULT_SUCCESS_V01) {
+		dev_err(drvdata->dev, "QMI request failed 0x%x\n",
+				resp.resp.error);
+		goto err;
+	}
+
+	drvdata->enable = false;
+	dev_info(drvdata->dev, "Remote ETM tracing disabled for instance %d\n",
+				drvdata->inst_id);
+err:
+	mutex_unlock(&drvdata->mutex);
+}
+
+static int remote_etm_trace_id(struct coresight_device *csdev)
+{
+	struct remote_etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	return drvdata->traceid;
+}
+
+static const struct coresight_ops_source remote_etm_source_ops = {
+	.trace_id	= remote_etm_trace_id,
+	.enable		= remote_etm_enable,
+	.disable	= remote_etm_disable,
+};
+
+static const struct coresight_ops remote_cs_ops = {
+	.source_ops	= &remote_etm_source_ops,
+};
+
+static int remote_etm_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct coresight_platform_data *pdata;
+	struct remote_etm_drvdata *drvdata;
+	struct coresight_desc desc = {0 };
+	int ret;
+	static int traceid = REMOTE_ETM_TRACE_ID_START;
+
+	desc.name = coresight_alloc_device_name(&remote_etm_devs, dev);
+	if (!desc.name)
+		return -ENOMEM;
+	pdata = coresight_get_platform_data(dev);
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
+	pdev->dev.platform_data = pdata;
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->dev = &pdev->dev;
+	platform_set_drvdata(pdev, drvdata);
+
+	ret = of_property_read_u32(pdev->dev.of_node, "qcom,inst-id",
+			&drvdata->inst_id);
+	if (ret)
+		return ret;
+
+	mutex_init(&drvdata->mutex);
+
+	ret = qmi_handle_init(&drvdata->handle,
+			CORESIGHT_QMI_SET_ETM_REQ_MAX_LEN,
+			&server_ops, NULL);
+	if (ret < 0) {
+		dev_err(dev, "Remote ETM client init failed ret:%d\n", ret);
+		return ret;
+	}
+
+	qmi_add_lookup(&drvdata->handle,
+			CORESIGHT_QMI_SVC_ID,
+			CORESIGHT_QMI_VERSION,
+			drvdata->inst_id);
+
+	drvdata->traceid = traceid++;
+
+	desc.type = CORESIGHT_DEV_TYPE_SOURCE;
+	desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;
+	desc.ops = &remote_cs_ops;
+	desc.pdata = pdev->dev.platform_data;
+	desc.dev = &pdev->dev;
+	drvdata->csdev = coresight_register(&desc);
+	if (IS_ERR(drvdata->csdev)) {
+		ret = PTR_ERR(drvdata->csdev);
+		goto err;
+	}
+	dev_info(dev, "Remote ETM initialized\n");
+
+	pm_runtime_enable(dev);
+	if (drvdata->inst_id >= sizeof(int)*BITS_PER_BYTE)
+		dev_err(dev, "inst_id greater than boot_enable bit mask\n");
+	else if (boot_enable & BIT(drvdata->inst_id))
+		coresight_enable(drvdata->csdev);
+
+	return 0;
+err:
+	qmi_handle_release(&drvdata->handle);
+	return ret;
+}
+
+static int remote_etm_remove(struct platform_device *pdev)
+{
+	struct remote_etm_drvdata *drvdata = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	pm_runtime_disable(dev);
+	qmi_handle_release(&drvdata->handle);
+	coresight_unregister(drvdata->csdev);
+	return 0;
+}
+
+static const struct of_device_id remote_etm_match[] = {
+	{.compatible = "qcom,coresight-remote-etm"},
+	{}
+};
+
+static struct platform_driver remote_etm_driver = {
+	.probe          = remote_etm_probe,
+	.remove         = remote_etm_remove,
+	.driver         = {
+		.name   = "coresight-remote-etm",
+		.of_match_table = remote_etm_match,
+	},
+};
+
+int __init remote_etm_init(void)
+{
+	return platform_driver_register(&remote_etm_driver);
+}
+module_init(remote_etm_init);
+
+void __exit remote_etm_exit(void)
+{
+	platform_driver_unregister(&remote_etm_driver);
+}
+module_exit(remote_etm_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CoreSight Remote ETM driver");