Introduce Protection Domain Restart (PDR) Helpers

Qualcomm SoCs (starting with MSM8998) allow for multiple protection domains to run on the same Q6 sub-system. This allows for services like ATH10K WLAN FW to have their own separate address space and crash/recover without disrupting the modem and other PDs running on the same sub-system. The PDR helpers introduces an abstraction that allows for tracking/controlling the life cycle of protection domains running on various Q6 sub-systems.

Signed-off-by Sibi Sankar <[email protected]>

---
 drivers/soc/qcom/Kconfig         |   5 +
 drivers/soc/qcom/Makefile        |   1 +
 drivers/soc/qcom/pdr_interface.c | 691 +++++++++++++++++++++++++++++++
 drivers/soc/qcom/pdr_internal.h  | 375 +++++++++++++++++
 include/linux/soc/qcom/pdr.h     | 105 +++++
 include/linux/soc/qcom/qmi.h     |   1 +
 6 files changed, 1178 insertions(+)
 create mode 100644 drivers/soc/qcom/pdr_interface.c
 create mode 100644 drivers/soc/qcom/pdr_internal.h
 create mode 100644 include/linux/soc/qcom/pdr.h

drivers/soc/qcom/Kconfig +5 -0

index 79d826553ac82..5c4e76837f59b 100644
@@ -76,6 +76,11 @@ config QCOM_OCMEM
           requirements. This is typically used by the GPU, camera/video, and
           audio components on some Snapdragon SoCs.
 
+config QCOM_PDR_HELPERS
+	tristate
+	depends on ARCH_QCOM || COMPILE_TEST
+	select QCOM_QMI_HELPERS
+
 config QCOM_PM
 	bool "Qualcomm Power Management"
 	depends on ARCH_QCOM && !ARM64

drivers/soc/qcom/Makefile +1 -0

index 9fb35c8a495e1..5d6b83dc58e82 100644
@@ -7,6 +7,7 @@ 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_OCMEM)	+= ocmem.o
+obj-$(CONFIG_QCOM_PDR_HELPERS)	+= pdr_interface.o
 obj-$(CONFIG_QCOM_PM)	+=	spm.o
 obj-$(CONFIG_QCOM_QMI_HELPERS)	+= qmi_helpers.o
 qmi_helpers-y	+= qmi_encdec.o qmi_interface.o

drivers/soc/qcom/pdr_interface.c new file +24 -0

new file mode 100644
index 0000000000000..2cfe012edd2f2
@@ -0,0 +1,691 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/completion.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/qrtr.h>
+#include <linux/string.h>
+#include <linux/workqueue.h>
+
+#include "pdr_internal.h"
+
+struct pdr_list_node {
+	u16 transaction_id;
+	struct pdr_service *pds;
+	struct list_head node;
+};
+
+static int servreg_locator_new_server(struct qmi_handle *qmi,
+				      struct qmi_service *svc)
+{
+	struct pdr_handle *pdr = container_of(qmi, struct pdr_handle,

drivers/soc/qcom/pdr_interface.c new file +28 -0

+	reinit_completion(&pdr->locator_available);
+}
+
+static struct qmi_ops service_locator_ops = {
+	.new_server = servreg_locator_new_server,
+	.del_server = servreg_locator_del_server,
+};
+
+static int pdr_register_listener(struct pdr_handle *pdr,
+				 struct pdr_service *pds,
+				 bool enable)
+{
+	struct servreg_register_listener_resp resp;
+	struct servreg_register_listener_req req;
+	struct qmi_txn txn;
+	int ret;
+
+	ret = qmi_txn_init(&pdr->servreg_client, &txn,
+			   servreg_register_listener_resp_ei,
+			   &resp);
+
+	if (ret < 0)
+		return ret;
+
+	req.enable = enable;
+	strcpy(req.service_path, pds->service_path);
+
+	ret = qmi_send_request(&pdr->servreg_client, &pdr->servreg_addr,

drivers/soc/qcom/pdr_interface.c new file +19 -0

+	if (ret < 0) {
+		pr_err("PDR: %s register listener txn wait failed: %d\n",
+		       pds->service_path, ret);
+		return ret;
+	}
+
+	/* Check the response */
+	if (resp.resp.result != QMI_RESULT_SUCCESS_V01) {
+		pr_err("PDR: %s register listener failed: 0x%x\n",
+		       pds->service_path, resp.resp.error);
+		return ret;
+	}
+
+	if ((int)resp.curr_state < INT_MIN || (int)resp.curr_state > INT_MAX)
+		pr_err("PDR: %s notification state invalid: 0x%x\n",
+		       pds->service_path, resp.curr_state);
+
+	pds->state = resp.curr_state;
+

drivers/soc/qcom/pdr_interface.c new file +61 -0

+}
+
+static int servreg_notifier_new_server(struct qmi_handle *qmi,
+				       struct qmi_service *svc)
+{
+	struct pdr_handle *pdr = container_of(qmi, struct pdr_handle,
+					      servreg_client);
+	struct pdr_list_node *servreg;
+	struct pdr_service *pds, *tmp;
+
+	/* Create a Local client port for QMI communication */
+	pdr->servreg_addr.sq_family = AF_QIPCRTR;
+	pdr->servreg_addr.sq_node = svc->node;
+	pdr->servreg_addr.sq_port = svc->port;
+
+	servreg = kzalloc(sizeof(*servreg), GFP_KERNEL);
+	if (!servreg)
+		return -ENOMEM;
+
+	list_for_each_entry_safe(pds, tmp, &pdr->lookups, node) {
+		if (pds->service == svc->service &&
+		    pds->instance == svc->instance) {
+			pds->service_connected = true;
+			servreg->pds = pds;
+			mutex_lock(&pdr->list_lock);
+			list_add_tail(&servreg->node, &pdr->servreg_list);
+			mutex_unlock(&pdr->list_lock);
+			break;
+		}
+	}
+
+	queue_work(pdr->servreg_wq, &pdr->servreg_work);
+
+	return 0;
+}
+
+static void pdr_servdel_work(struct work_struct *work)
+{
+	struct pdr_handle *pdr = container_of(work, struct pdr_handle,
+					      servdel_work);
+	struct pdr_list_node *servreg, *tmp;
+	struct pdr_service *pds;
+
+	list_for_each_entry_safe(servreg, tmp, &pdr->servdel_list, node) {
+		pds = servreg->pds;
+		pds->service_connected = false;
+		pds->state = SERVREG_SERVICE_STATE_DOWN;
+		mutex_lock(&pdr->status_lock);
+		pdr->status(pdr, pds);
+		mutex_unlock(&pdr->status_lock);
+		list_del(&servreg->node);
+		kfree(servreg);
+	}
+}
+
+static void servreg_notifier_del_server(struct qmi_handle *qmi,
+					struct qmi_service *svc)
+{
+	struct pdr_handle *pdr = container_of(qmi, struct pdr_handle,
+					      servreg_client);
+	struct pdr_list_node *servreg;

drivers/soc/qcom/pdr_interface.c new file +42 -0

+			mutex_lock(&pdr->list_lock);
+			list_add_tail(&servreg->node, &pdr->servdel_list);
+			mutex_unlock(&pdr->list_lock);
+			break;
+		}
+	}
+
+	queue_work(pdr->servreg_wq, &pdr->servdel_work);
+}
+
+static struct qmi_ops service_notifier_ops = {
+	.new_server = servreg_notifier_new_server,
+	.del_server = servreg_notifier_del_server,
+};
+
+static int pdr_send_indack_msg(struct pdr_handle *pdr, struct pdr_service *pds,
+			       u16 tid)
+{
+	struct servreg_set_ack_resp resp;
+	struct servreg_set_ack_req req;
+	struct qmi_txn txn;
+	int ret;
+
+	ret = qmi_txn_init(&pdr->servreg_client, &txn, servreg_set_ack_resp_ei,
+			   &resp);
+	if (ret < 0)
+		return ret;
+
+	req.transaction_id = tid;
+	strcpy(req.service_path, pds->service_path);
+
+	ret = qmi_send_request(&pdr->servreg_client, &pdr->servreg_addr,
+			       &txn, SERVREG_SET_ACK_REQ,
+			       SERVREG_SET_ACK_REQ_LEN,
+			       servreg_set_ack_req_ei,
+			       &req);
+	if (ret < 0) {
+		qmi_txn_cancel(&txn);
+		return ret;
+	}
+
+	ret = qmi_txn_wait(&txn, 5 * HZ);

drivers/soc/qcom/pdr_interface.c new file +173 -0

+
+	return 0;
+}
+
+static void pdr_indack_work(struct work_struct *work)
+{
+	struct pdr_handle *pdr = container_of(work, struct pdr_handle,
+					      indack_work);
+	struct pdr_list_node *ind, *tmp;
+	struct pdr_service *pds;
+
+	list_for_each_entry_safe(ind, tmp, &pdr->indack_list, node) {
+		pds = ind->pds;
+		pdr_send_indack_msg(pdr, pds, ind->transaction_id);
+		mutex_lock(&pdr->status_lock);
+		pdr->status(pdr, pds);
+		mutex_unlock(&pdr->status_lock);
+		list_del(&ind->node);
+		kfree(ind);
+	}
+}
+
+static void pdr_servreg_ind_cb(struct qmi_handle *qmi,
+			       struct sockaddr_qrtr *sq,
+			       struct qmi_txn *txn, const void *data)
+{
+	struct pdr_handle *pdr = container_of(qmi, struct pdr_handle,
+					      servreg_client);
+	const struct servreg_state_updated_ind *ind_msg = data;
+	struct pdr_list_node *ind;
+	struct pdr_service *pds;
+
+	if (!ind_msg || !ind_msg->service_path ||
+	    strlen(ind_msg->service_path) > SERVREG_NAME_LENGTH)
+		return;
+
+	list_for_each_entry(pds, &pdr->lookups, node) {
+		if (!strcmp(pds->service_path, ind_msg->service_path))
+			goto found;
+	}
+	return;
+
+found:
+	pds->state = ind_msg->curr_state;
+
+	ind = kzalloc(sizeof(*ind), GFP_KERNEL);
+	if (!ind)
+		return;
+
+	pr_info("PDR: Indication received from %s, state: 0x%x, trans-id: %d\n",
+		ind_msg->service_path, ind_msg->curr_state,
+		ind_msg->transaction_id);
+
+	ind->transaction_id = ind_msg->transaction_id;
+	ind->pds = pds;
+
+	mutex_lock(&pdr->list_lock);
+	list_add_tail(&ind->node, &pdr->indack_list);
+	mutex_unlock(&pdr->list_lock);
+
+	queue_work(pdr->indack_wq, &pdr->indack_work);
+}
+
+static struct qmi_msg_handler qmi_indication_handler[] = {
+	{
+		.type = QMI_INDICATION,
+		.msg_id = SERVREG_STATE_UPDATED_IND_ID,
+		.ei = servreg_state_updated_ind_ei,
+		.decoded_size = sizeof(struct servreg_state_updated_ind),
+		.fn = pdr_servreg_ind_cb,
+	},
+	{}
+};
+
+static int pdr_get_domain_list(struct servreg_get_domain_list_req *req,
+			       struct servreg_get_domain_list_resp *resp,
+			       struct pdr_handle *pdr)
+{
+	struct qmi_txn txn;
+	int ret;
+
+	ret = qmi_txn_init(&pdr->servloc_client, &txn,
+			   servreg_get_domain_list_resp_ei, resp);
+	if (ret < 0)
+		return ret;
+
+	ret = qmi_send_request(&pdr->servloc_client,
+			       &pdr->servloc_addr,
+			       &txn, SERVREG_GET_DOMAIN_LIST_REQ,
+			       SERVREG_GET_DOMAIN_LIST_REQ_MAX_LEN,
+			       servreg_get_domain_list_req_ei,
+			       req);
+	if (ret < 0) {
+		qmi_txn_cancel(&txn);
+		return ret;
+	}
+
+	ret = qmi_txn_wait(&txn, 5 * HZ);
+	if (ret < 0) {
+		pr_err("PDR: %s get domain list txn wait failed: %d\n",
+		       req->service_name, ret);
+		return ret;
+	}
+
+	/* Check the response */
+	if (resp->resp.result != QMI_RESULT_SUCCESS_V01) {
+		pr_err("PDR: %s get domain list failed: 0x%x\n",
+		       req->service_name, resp->resp.error);
+		return -EREMOTEIO;
+	}
+
+	return 0;
+}
+
+static int pdr_locate_service(struct pdr_handle *pdr, struct pdr_service *pds)
+{
+	struct servreg_get_domain_list_resp *resp = NULL;
+	struct servreg_get_domain_list_req req;
+	int db_rev_count = 0, domains_read = 0;
+	struct servreg_location_entry *entry;
+	int ret, i;
+
+	resp = kzalloc(sizeof(*resp), GFP_KERNEL);
+	if (!resp)
+		return -ENOMEM;
+
+	/* Prepare req message */
+	strcpy(req.service_name, pds->service_name);
+	req.domain_offset_valid = true;
+	req.domain_offset = 0;
+
+	do {
+		req.domain_offset = domains_read;
+		ret = pdr_get_domain_list(&req, resp, pdr);
+		if (ret < 0)
+			goto out;
+
+		if (!domains_read)
+			db_rev_count = resp->db_rev_count;
+
+		if (db_rev_count != resp->db_rev_count) {
+			ret = -EAGAIN;
+			goto out;
+		}
+
+		for (i = domains_read; i < resp->domain_list_len; i++) {
+			entry = &resp->domain_list[i];
+
+			if (strnlen(entry->name, sizeof(entry->name)) == sizeof(entry->name))
+				continue;
+
+			if (!strcmp(entry->name, pds->service_path)) {
+				pds->service_data_valid = entry->service_data_valid;
+				pds->service_data = entry->service_data;
+				pds->instance = entry->instance;
+				goto out;
+			}
+		}
+
+		/* Update ret to indicate that the service is not yet found */
+		ret = -EINVAL;
+
+		/* Always read total_domains from the response msg */
+		if (resp->domain_list_len > resp->total_domains)
+			resp->domain_list_len = resp->total_domains;
+
+		domains_read += resp->domain_list_len;
+	} while (domains_read < resp->total_domains);
+out:
+	kfree(resp);
+	return ret;
+}
+

drivers/soc/qcom/pdr_interface.c new file +52 -0

+			mutex_unlock(&pdr->status_lock);
+			pr_err("PDR: service lookup for %s failed: %d\n",
+			       pds->service_name, ret);
+			list_del(&pds->node);
+			kfree(pds);
+		} else {
+			qmi_add_lookup(&pdr->servreg_client, pds->service, 1,
+				       pds->instance);
+		}
+
+		list_del(&servloc->node);
+		kfree(servloc);
+	}
+}
+
+/**
+ * pdr_add_lookup() - register a tracking request for a PD
+ * @pdr:		PDR client handle
+ * @service_name:	service name of the tracking request
+ * @service_path:	service path of the tracking request
+ *
+ * Registering a pdr lookup allows for tracking the life cycle of the PD.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int pdr_add_lookup(struct pdr_handle *pdr, const char *service_name,
+		   const char *service_path)
+{
+	struct pdr_service *pds, *pds_iter, *tmp;
+	struct pdr_list_node *servloc;
+	int ret;
+
+	if (!service_name || strlen(service_name) > SERVREG_NAME_LENGTH ||
+	    !service_path || strlen(service_path) > SERVREG_NAME_LENGTH)
+		return -EINVAL;
+
+	servloc = kzalloc(sizeof(*servloc), GFP_KERNEL);
+	if (!servloc)
+		return -ENOMEM;
+
+	pds = kzalloc(sizeof(*pds), GFP_KERNEL);
+	if (!pds) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	pds->service = SERVREG_NOTIFIER_SERVICE;
+	strcpy(pds->service_name, service_name);
+	strcpy(pds->service_path, service_path);
+	servloc->pds = pds;
+
+	mutex_lock(&pdr->list_lock);

drivers/soc/qcom/pdr_interface.c new file +164 -0

+	mutex_unlock(&pdr->list_lock);
+
+	schedule_work(&pdr->servloc_work);
+
+	return 0;
+err:
+	kfree(pds);
+	kfree(servloc);
+
+	return ret;
+}
+EXPORT_SYMBOL(pdr_add_lookup);
+
+/**
+ * pdr_restart_pd() - restart PD
+ * @pdr:		PDR client handle
+ * @service_path:	service path of restart request
+ *
+ * Restarts the PD tracked by the PDR client handle for a given service path.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int pdr_restart_pd(struct pdr_handle *pdr, const char *service_path)
+{
+	struct servreg_restart_pd_req req;
+	struct servreg_restart_pd_resp resp;
+	struct pdr_service *pds = NULL, *pds_iter, *tmp;
+	struct qmi_txn txn;
+	int ret;
+
+	if (!service_path || strlen(service_path) > SERVREG_NAME_LENGTH)
+		return -EINVAL;
+
+	list_for_each_entry_safe(pds_iter, tmp, &pdr->lookups, node) {
+		if (!pds_iter->service_connected)
+			continue;
+
+		if (!strcmp(pds_iter->service_path, service_path)) {
+			pds = pds_iter;
+			break;
+		}
+	}
+
+	if (!pds)
+		return -EINVAL;
+
+	/* Prepare req message */
+	strcpy(req.service_path, pds->service_path);
+
+	ret = qmi_txn_init(&pdr->servreg_client, &txn,
+			   servreg_restart_pd_resp_ei,
+			   &resp);
+	if (ret < 0)
+		return ret;
+
+	ret = qmi_send_request(&pdr->servreg_client, &pdr->servreg_addr,
+			       &txn, SERVREG_RESTART_PD_REQ,
+			       SERVREG_RESTART_PD_REQ_MAX_LEN,
+			       servreg_restart_pd_req_ei, &req);
+	if (ret < 0) {
+		qmi_txn_cancel(&txn);
+		return ret;
+	}
+
+	ret = qmi_txn_wait(&txn, 5 * HZ);
+	if (ret < 0) {
+		pr_err("PDR: %s PD restart txn wait failed: %d\n",
+		       pds->service_path, ret);
+		return ret;
+	}
+
+	/* Check response if PDR is disabled */
+	if (resp.resp.result == QMI_RESULT_FAILURE_V01 &&
+	    resp.resp.error == QMI_ERR_DISABLED_V01) {
+		pr_err("PDR: %s PD restart is disabled: 0x%x\n",
+		       pds->service_path, resp.resp.error);
+		return -EOPNOTSUPP;
+	}
+
+	/* Check the response for other error case*/
+	if (resp.resp.result != QMI_RESULT_SUCCESS_V01) {
+		pr_err("PDR: %s request for PD restart failed: 0x%x\n",
+		       pds->service_path, resp.resp.error);
+		return -EREMOTEIO;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(pdr_restart_pd);
+
+/**
+ * pdr_handle_init() - initialize the PDR client handle
+ * @pdr:	PDR client handle
+ * @status:	function to be called on PD state change
+ *
+ * Initializes the PDR client handle to allow for tracking/restart of PDs.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int pdr_handle_init(struct pdr_handle *pdr,
+		    void (*status)(struct pdr_handle *pdr,
+				   struct pdr_service *pds))
+{
+	int ret;
+
+	if (!status)
+		return -EINVAL;
+
+	pdr->status = *status;
+
+	mutex_init(&pdr->list_lock);
+	mutex_init(&pdr->status_lock);
+	init_completion(&pdr->locator_available);
+
+	INIT_LIST_HEAD(&pdr->lookups);
+	INIT_LIST_HEAD(&pdr->servloc_list);
+	INIT_LIST_HEAD(&pdr->servreg_list);
+	INIT_LIST_HEAD(&pdr->servdel_list);
+	INIT_LIST_HEAD(&pdr->indack_list);
+
+	INIT_WORK(&pdr->servloc_work, pdr_servloc_work);
+	INIT_WORK(&pdr->servreg_work, pdr_servreg_work);
+	INIT_WORK(&pdr->servdel_work, pdr_servdel_work);
+	INIT_WORK(&pdr->indack_work, pdr_indack_work);
+
+	pdr->servreg_wq = create_singlethread_workqueue("pdr_servreg_wq");
+	if (!pdr->servreg_wq)
+		return -ENOMEM;
+
+	pdr->indack_wq = alloc_ordered_workqueue("pdr_indack_wq", WQ_HIGHPRI);
+	if (!pdr->indack_wq) {
+		ret = -ENOMEM;
+		goto destroy_servreg;
+	}
+
+	ret = qmi_handle_init(&pdr->servloc_client,
+			      SERVREG_GET_DOMAIN_LIST_RESP_MAX_LEN,
+			      &service_locator_ops, NULL);
+	if (ret < 0)
+		goto destroy_indack;
+
+	ret = qmi_handle_init(&pdr->servreg_client,
+			      SERVREG_STATE_UPDATED_IND_MAX_LEN,
+			      &service_notifier_ops, qmi_indication_handler);
+	if (ret < 0)
+		goto release_handle;
+
+	qmi_add_lookup(&pdr->servloc_client, SERVREG_LOCATOR_SERVICE, 1, 1);
+
+	return 0;
+
+release_handle:
+	qmi_handle_release(&pdr->servloc_client);
+destroy_indack:
+	destroy_workqueue(pdr->indack_wq);
+destroy_servreg:
+	destroy_workqueue(pdr->servreg_wq);
+
+	return ret;
+}
+EXPORT_SYMBOL(pdr_handle_init);
+
+/**
+ * pdr_handle_release() - release the PDR client handle