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path: root/drivers/remoteproc/qcom_sysmon.c
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Diffstat (limited to 'drivers/remoteproc/qcom_sysmon.c')
-rw-r--r--drivers/remoteproc/qcom_sysmon.c810
1 files changed, 810 insertions, 0 deletions
diff --git a/drivers/remoteproc/qcom_sysmon.c b/drivers/remoteproc/qcom_sysmon.c
new file mode 100644
index 0000000000..c24e4a8828
--- /dev/null
+++ b/drivers/remoteproc/qcom_sysmon.c
@@ -0,0 +1,810 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2017, Linaro Ltd.
+ */
+#include <linux/firmware.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/remoteproc/qcom_rproc.h>
+#include <linux/rpmsg.h>
+
+#include "qcom_common.h"
+
+static BLOCKING_NOTIFIER_HEAD(sysmon_notifiers);
+
+struct qcom_sysmon {
+ struct rproc_subdev subdev;
+ struct rproc *rproc;
+
+ int state;
+ struct mutex state_lock;
+
+ struct list_head node;
+
+ const char *name;
+
+ int shutdown_irq;
+ int ssctl_version;
+ int ssctl_instance;
+
+ struct notifier_block nb;
+
+ struct device *dev;
+
+ struct rpmsg_endpoint *ept;
+ struct completion comp;
+ struct completion ind_comp;
+ struct completion shutdown_comp;
+ struct completion ssctl_comp;
+ struct mutex lock;
+
+ bool ssr_ack;
+ bool shutdown_acked;
+
+ struct qmi_handle qmi;
+ struct sockaddr_qrtr ssctl;
+};
+
+enum {
+ SSCTL_SSR_EVENT_BEFORE_POWERUP,
+ SSCTL_SSR_EVENT_AFTER_POWERUP,
+ SSCTL_SSR_EVENT_BEFORE_SHUTDOWN,
+ SSCTL_SSR_EVENT_AFTER_SHUTDOWN,
+};
+
+static const char * const sysmon_state_string[] = {
+ [SSCTL_SSR_EVENT_BEFORE_POWERUP] = "before_powerup",
+ [SSCTL_SSR_EVENT_AFTER_POWERUP] = "after_powerup",
+ [SSCTL_SSR_EVENT_BEFORE_SHUTDOWN] = "before_shutdown",
+ [SSCTL_SSR_EVENT_AFTER_SHUTDOWN] = "after_shutdown",
+};
+
+struct sysmon_event {
+ const char *subsys_name;
+ u32 ssr_event;
+};
+
+static DEFINE_MUTEX(sysmon_lock);
+static LIST_HEAD(sysmon_list);
+
+/**
+ * sysmon_send_event() - send notification of other remote's SSR event
+ * @sysmon: sysmon context
+ * @event: sysmon event context
+ */
+static void sysmon_send_event(struct qcom_sysmon *sysmon,
+ const struct sysmon_event *event)
+{
+ char req[50];
+ int len;
+ int ret;
+
+ len = snprintf(req, sizeof(req), "ssr:%s:%s", event->subsys_name,
+ sysmon_state_string[event->ssr_event]);
+ if (len >= sizeof(req))
+ return;
+
+ mutex_lock(&sysmon->lock);
+ reinit_completion(&sysmon->comp);
+ sysmon->ssr_ack = false;
+
+ ret = rpmsg_send(sysmon->ept, req, len);
+ if (ret < 0) {
+ dev_err(sysmon->dev, "failed to send sysmon event\n");
+ goto out_unlock;
+ }
+
+ ret = wait_for_completion_timeout(&sysmon->comp,
+ msecs_to_jiffies(5000));
+ if (!ret) {
+ dev_err(sysmon->dev, "timeout waiting for sysmon ack\n");
+ goto out_unlock;
+ }
+
+ if (!sysmon->ssr_ack)
+ dev_err(sysmon->dev, "unexpected response to sysmon event\n");
+
+out_unlock:
+ mutex_unlock(&sysmon->lock);
+}
+
+/**
+ * sysmon_request_shutdown() - request graceful shutdown of remote
+ * @sysmon: sysmon context
+ *
+ * Return: boolean indicator of the remote processor acking the request
+ */
+static bool sysmon_request_shutdown(struct qcom_sysmon *sysmon)
+{
+ char *req = "ssr:shutdown";
+ bool acked = false;
+ int ret;
+
+ mutex_lock(&sysmon->lock);
+ reinit_completion(&sysmon->comp);
+ sysmon->ssr_ack = false;
+
+ ret = rpmsg_send(sysmon->ept, req, strlen(req) + 1);
+ if (ret < 0) {
+ dev_err(sysmon->dev, "send sysmon shutdown request failed\n");
+ goto out_unlock;
+ }
+
+ ret = wait_for_completion_timeout(&sysmon->comp,
+ msecs_to_jiffies(5000));
+ if (!ret) {
+ dev_err(sysmon->dev, "timeout waiting for sysmon ack\n");
+ goto out_unlock;
+ }
+
+ if (!sysmon->ssr_ack)
+ dev_err(sysmon->dev,
+ "unexpected response to sysmon shutdown request\n");
+ else
+ acked = true;
+
+out_unlock:
+ mutex_unlock(&sysmon->lock);
+
+ return acked;
+}
+
+static int sysmon_callback(struct rpmsg_device *rpdev, void *data, int count,
+ void *priv, u32 addr)
+{
+ struct qcom_sysmon *sysmon = priv;
+ const char *ssr_ack = "ssr:ack";
+ const int ssr_ack_len = strlen(ssr_ack) + 1;
+
+ if (!sysmon)
+ return -EINVAL;
+
+ if (count >= ssr_ack_len && !memcmp(data, ssr_ack, ssr_ack_len))
+ sysmon->ssr_ack = true;
+
+ complete(&sysmon->comp);
+
+ return 0;
+}
+
+#define SSCTL_SHUTDOWN_REQ 0x21
+#define SSCTL_SHUTDOWN_READY_IND 0x21
+#define SSCTL_SUBSYS_EVENT_REQ 0x23
+
+#define SSCTL_MAX_MSG_LEN 7
+
+#define SSCTL_SUBSYS_NAME_LENGTH 15
+
+enum {
+ SSCTL_SSR_EVENT_FORCED,
+ SSCTL_SSR_EVENT_GRACEFUL,
+};
+
+struct ssctl_shutdown_resp {
+ struct qmi_response_type_v01 resp;
+};
+
+static const struct qmi_elem_info ssctl_shutdown_resp_ei[] = {
+ {
+ .data_type = QMI_STRUCT,
+ .elem_len = 1,
+ .elem_size = sizeof(struct qmi_response_type_v01),
+ .array_type = NO_ARRAY,
+ .tlv_type = 0x02,
+ .offset = offsetof(struct ssctl_shutdown_resp, resp),
+ .ei_array = qmi_response_type_v01_ei,
+ },
+ {}
+};
+
+struct ssctl_subsys_event_req {
+ u8 subsys_name_len;
+ char subsys_name[SSCTL_SUBSYS_NAME_LENGTH];
+ u32 event;
+ u8 evt_driven_valid;
+ u32 evt_driven;
+};
+
+static const struct qmi_elem_info ssctl_subsys_event_req_ei[] = {
+ {
+ .data_type = QMI_DATA_LEN,
+ .elem_len = 1,
+ .elem_size = sizeof(uint8_t),
+ .array_type = NO_ARRAY,
+ .tlv_type = 0x01,
+ .offset = offsetof(struct ssctl_subsys_event_req,
+ subsys_name_len),
+ .ei_array = NULL,
+ },
+ {
+ .data_type = QMI_UNSIGNED_1_BYTE,
+ .elem_len = SSCTL_SUBSYS_NAME_LENGTH,
+ .elem_size = sizeof(char),
+ .array_type = VAR_LEN_ARRAY,
+ .tlv_type = 0x01,
+ .offset = offsetof(struct ssctl_subsys_event_req,
+ subsys_name),
+ .ei_array = NULL,
+ },
+ {
+ .data_type = QMI_SIGNED_4_BYTE_ENUM,
+ .elem_len = 1,
+ .elem_size = sizeof(uint32_t),
+ .array_type = NO_ARRAY,
+ .tlv_type = 0x02,
+ .offset = offsetof(struct ssctl_subsys_event_req,
+ event),
+ .ei_array = NULL,
+ },
+ {
+ .data_type = QMI_OPT_FLAG,
+ .elem_len = 1,
+ .elem_size = sizeof(uint8_t),
+ .array_type = NO_ARRAY,
+ .tlv_type = 0x10,
+ .offset = offsetof(struct ssctl_subsys_event_req,
+ evt_driven_valid),
+ .ei_array = NULL,
+ },
+ {
+ .data_type = QMI_SIGNED_4_BYTE_ENUM,
+ .elem_len = 1,
+ .elem_size = sizeof(uint32_t),
+ .array_type = NO_ARRAY,
+ .tlv_type = 0x10,
+ .offset = offsetof(struct ssctl_subsys_event_req,
+ evt_driven),
+ .ei_array = NULL,
+ },
+ {}
+};
+
+struct ssctl_subsys_event_resp {
+ struct qmi_response_type_v01 resp;
+};
+
+static const struct qmi_elem_info ssctl_subsys_event_resp_ei[] = {
+ {
+ .data_type = QMI_STRUCT,
+ .elem_len = 1,
+ .elem_size = sizeof(struct qmi_response_type_v01),
+ .array_type = NO_ARRAY,
+ .tlv_type = 0x02,
+ .offset = offsetof(struct ssctl_subsys_event_resp,
+ resp),
+ .ei_array = qmi_response_type_v01_ei,
+ },
+ {}
+};
+
+static const struct qmi_elem_info ssctl_shutdown_ind_ei[] = {
+ {}
+};
+
+static void sysmon_ind_cb(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+ struct qmi_txn *txn, const void *data)
+{
+ struct qcom_sysmon *sysmon = container_of(qmi, struct qcom_sysmon, qmi);
+
+ complete(&sysmon->ind_comp);
+}
+
+static const struct qmi_msg_handler qmi_indication_handler[] = {
+ {
+ .type = QMI_INDICATION,
+ .msg_id = SSCTL_SHUTDOWN_READY_IND,
+ .ei = ssctl_shutdown_ind_ei,
+ .decoded_size = 0,
+ .fn = sysmon_ind_cb
+ },
+ {}
+};
+
+static bool ssctl_request_shutdown_wait(struct qcom_sysmon *sysmon)
+{
+ int ret;
+
+ ret = wait_for_completion_timeout(&sysmon->shutdown_comp, 10 * HZ);
+ if (ret)
+ return true;
+
+ ret = try_wait_for_completion(&sysmon->ind_comp);
+ if (ret)
+ return true;
+
+ dev_err(sysmon->dev, "timeout waiting for shutdown ack\n");
+ return false;
+}
+
+/**
+ * ssctl_request_shutdown() - request shutdown via SSCTL QMI service
+ * @sysmon: sysmon context
+ *
+ * Return: boolean indicator of the remote processor acking the request
+ */
+static bool ssctl_request_shutdown(struct qcom_sysmon *sysmon)
+{
+ struct ssctl_shutdown_resp resp;
+ struct qmi_txn txn;
+ bool acked = false;
+ int ret;
+
+ reinit_completion(&sysmon->ind_comp);
+ reinit_completion(&sysmon->shutdown_comp);
+ ret = qmi_txn_init(&sysmon->qmi, &txn, ssctl_shutdown_resp_ei, &resp);
+ if (ret < 0) {
+ dev_err(sysmon->dev, "failed to allocate QMI txn\n");
+ return false;
+ }
+
+ ret = qmi_send_request(&sysmon->qmi, &sysmon->ssctl, &txn,
+ SSCTL_SHUTDOWN_REQ, 0, NULL, NULL);
+ if (ret < 0) {
+ dev_err(sysmon->dev, "failed to send shutdown request\n");
+ qmi_txn_cancel(&txn);
+ return false;
+ }
+
+ ret = qmi_txn_wait(&txn, 5 * HZ);
+ if (ret < 0) {
+ dev_err(sysmon->dev, "timeout waiting for shutdown response\n");
+ } else if (resp.resp.result) {
+ dev_err(sysmon->dev, "shutdown request rejected\n");
+ } else {
+ dev_dbg(sysmon->dev, "shutdown request completed\n");
+ acked = true;
+ }
+
+ if (sysmon->shutdown_irq > 0)
+ return ssctl_request_shutdown_wait(sysmon);
+
+ return acked;
+}
+
+/**
+ * ssctl_send_event() - send notification of other remote's SSR event
+ * @sysmon: sysmon context
+ * @event: sysmon event context
+ */
+static void ssctl_send_event(struct qcom_sysmon *sysmon,
+ const struct sysmon_event *event)
+{
+ struct ssctl_subsys_event_resp resp;
+ struct ssctl_subsys_event_req req;
+ struct qmi_txn txn;
+ int ret;
+
+ memset(&resp, 0, sizeof(resp));
+ ret = qmi_txn_init(&sysmon->qmi, &txn, ssctl_subsys_event_resp_ei, &resp);
+ if (ret < 0) {
+ dev_err(sysmon->dev, "failed to allocate QMI txn\n");
+ return;
+ }
+
+ memset(&req, 0, sizeof(req));
+ strscpy(req.subsys_name, event->subsys_name, sizeof(req.subsys_name));
+ req.subsys_name_len = strlen(req.subsys_name);
+ req.event = event->ssr_event;
+ req.evt_driven_valid = true;
+ req.evt_driven = SSCTL_SSR_EVENT_FORCED;
+
+ ret = qmi_send_request(&sysmon->qmi, &sysmon->ssctl, &txn,
+ SSCTL_SUBSYS_EVENT_REQ, 40,
+ ssctl_subsys_event_req_ei, &req);
+ if (ret < 0) {
+ dev_err(sysmon->dev, "failed to send subsystem event\n");
+ qmi_txn_cancel(&txn);
+ return;
+ }
+
+ ret = qmi_txn_wait(&txn, 5 * HZ);
+ if (ret < 0)
+ dev_err(sysmon->dev, "timeout waiting for subsystem event response\n");
+ else if (resp.resp.result)
+ dev_err(sysmon->dev, "subsystem event rejected\n");
+ else
+ dev_dbg(sysmon->dev, "subsystem event accepted\n");
+}
+
+/**
+ * ssctl_new_server() - QMI callback indicating a new service
+ * @qmi: QMI handle
+ * @svc: service information
+ *
+ * Return: 0 if we're interested in this service, -EINVAL otherwise.
+ */
+static int ssctl_new_server(struct qmi_handle *qmi, struct qmi_service *svc)
+{
+ struct qcom_sysmon *sysmon = container_of(qmi, struct qcom_sysmon, qmi);
+
+ switch (svc->version) {
+ case 1:
+ if (svc->instance != 0)
+ return -EINVAL;
+ if (strcmp(sysmon->name, "modem"))
+ return -EINVAL;
+ break;
+ case 2:
+ if (svc->instance != sysmon->ssctl_instance)
+ return -EINVAL;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ sysmon->ssctl_version = svc->version;
+
+ sysmon->ssctl.sq_family = AF_QIPCRTR;
+ sysmon->ssctl.sq_node = svc->node;
+ sysmon->ssctl.sq_port = svc->port;
+
+ svc->priv = sysmon;
+
+ complete(&sysmon->ssctl_comp);
+
+ return 0;
+}
+
+/**
+ * ssctl_del_server() - QMI callback indicating that @svc is removed
+ * @qmi: QMI handle
+ * @svc: service information
+ */
+static void ssctl_del_server(struct qmi_handle *qmi, struct qmi_service *svc)
+{
+ struct qcom_sysmon *sysmon = svc->priv;
+
+ sysmon->ssctl_version = 0;
+}
+
+static const struct qmi_ops ssctl_ops = {
+ .new_server = ssctl_new_server,
+ .del_server = ssctl_del_server,
+};
+
+static int sysmon_prepare(struct rproc_subdev *subdev)
+{
+ struct qcom_sysmon *sysmon = container_of(subdev, struct qcom_sysmon,
+ subdev);
+ struct sysmon_event event = {
+ .subsys_name = sysmon->name,
+ .ssr_event = SSCTL_SSR_EVENT_BEFORE_POWERUP
+ };
+
+ mutex_lock(&sysmon->state_lock);
+ sysmon->state = SSCTL_SSR_EVENT_BEFORE_POWERUP;
+ blocking_notifier_call_chain(&sysmon_notifiers, 0, (void *)&event);
+ mutex_unlock(&sysmon->state_lock);
+
+ return 0;
+}
+
+/**
+ * sysmon_start() - start callback for the sysmon remoteproc subdevice
+ * @subdev: instance of the sysmon subdevice
+ *
+ * Inform all the listners of sysmon notifications that the rproc associated
+ * to @subdev has booted up. The rproc that booted up also needs to know
+ * which rprocs are already up and running, so send start notifications
+ * on behalf of all the online rprocs.
+ */
+static int sysmon_start(struct rproc_subdev *subdev)
+{
+ struct qcom_sysmon *sysmon = container_of(subdev, struct qcom_sysmon,
+ subdev);
+ struct qcom_sysmon *target;
+ struct sysmon_event event = {
+ .subsys_name = sysmon->name,
+ .ssr_event = SSCTL_SSR_EVENT_AFTER_POWERUP
+ };
+
+ reinit_completion(&sysmon->ssctl_comp);
+ mutex_lock(&sysmon->state_lock);
+ sysmon->state = SSCTL_SSR_EVENT_AFTER_POWERUP;
+ blocking_notifier_call_chain(&sysmon_notifiers, 0, (void *)&event);
+ mutex_unlock(&sysmon->state_lock);
+
+ mutex_lock(&sysmon_lock);
+ list_for_each_entry(target, &sysmon_list, node) {
+ mutex_lock(&target->state_lock);
+ if (target == sysmon || target->state != SSCTL_SSR_EVENT_AFTER_POWERUP) {
+ mutex_unlock(&target->state_lock);
+ continue;
+ }
+
+ event.subsys_name = target->name;
+ event.ssr_event = target->state;
+
+ if (sysmon->ssctl_version == 2)
+ ssctl_send_event(sysmon, &event);
+ else if (sysmon->ept)
+ sysmon_send_event(sysmon, &event);
+ mutex_unlock(&target->state_lock);
+ }
+ mutex_unlock(&sysmon_lock);
+
+ return 0;
+}
+
+static void sysmon_stop(struct rproc_subdev *subdev, bool crashed)
+{
+ struct qcom_sysmon *sysmon = container_of(subdev, struct qcom_sysmon, subdev);
+ struct sysmon_event event = {
+ .subsys_name = sysmon->name,
+ .ssr_event = SSCTL_SSR_EVENT_BEFORE_SHUTDOWN
+ };
+
+ sysmon->shutdown_acked = false;
+
+ mutex_lock(&sysmon->state_lock);
+ sysmon->state = SSCTL_SSR_EVENT_BEFORE_SHUTDOWN;
+ blocking_notifier_call_chain(&sysmon_notifiers, 0, (void *)&event);
+ mutex_unlock(&sysmon->state_lock);
+
+ /* Don't request graceful shutdown if we've crashed */
+ if (crashed)
+ return;
+
+ if (sysmon->ssctl_instance) {
+ if (!wait_for_completion_timeout(&sysmon->ssctl_comp, HZ / 2))
+ dev_err(sysmon->dev, "timeout waiting for ssctl service\n");
+ }
+
+ if (sysmon->ssctl_version)
+ sysmon->shutdown_acked = ssctl_request_shutdown(sysmon);
+ else if (sysmon->ept)
+ sysmon->shutdown_acked = sysmon_request_shutdown(sysmon);
+}
+
+static void sysmon_unprepare(struct rproc_subdev *subdev)
+{
+ struct qcom_sysmon *sysmon = container_of(subdev, struct qcom_sysmon,
+ subdev);
+ struct sysmon_event event = {
+ .subsys_name = sysmon->name,
+ .ssr_event = SSCTL_SSR_EVENT_AFTER_SHUTDOWN
+ };
+
+ mutex_lock(&sysmon->state_lock);
+ sysmon->state = SSCTL_SSR_EVENT_AFTER_SHUTDOWN;
+ blocking_notifier_call_chain(&sysmon_notifiers, 0, (void *)&event);
+ mutex_unlock(&sysmon->state_lock);
+}
+
+/**
+ * sysmon_notify() - notify sysmon target of another's SSR
+ * @nb: notifier_block associated with sysmon instance
+ * @event: unused
+ * @data: SSR identifier of the remote that is going down
+ */
+static int sysmon_notify(struct notifier_block *nb, unsigned long event,
+ void *data)
+{
+ struct qcom_sysmon *sysmon = container_of(nb, struct qcom_sysmon, nb);
+ struct sysmon_event *sysmon_event = data;
+
+ /* Skip non-running rprocs and the originating instance */
+ if (sysmon->state != SSCTL_SSR_EVENT_AFTER_POWERUP ||
+ !strcmp(sysmon_event->subsys_name, sysmon->name)) {
+ dev_dbg(sysmon->dev, "not notifying %s\n", sysmon->name);
+ return NOTIFY_DONE;
+ }
+
+ /* Only SSCTL version 2 supports SSR events */
+ if (sysmon->ssctl_version == 2)
+ ssctl_send_event(sysmon, sysmon_event);
+ else if (sysmon->ept)
+ sysmon_send_event(sysmon, sysmon_event);
+
+ return NOTIFY_DONE;
+}
+
+static irqreturn_t sysmon_shutdown_interrupt(int irq, void *data)
+{
+ struct qcom_sysmon *sysmon = data;
+
+ complete(&sysmon->shutdown_comp);
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * qcom_add_sysmon_subdev() - create a sysmon subdev for the given remoteproc
+ * @rproc: rproc context to associate the subdev with
+ * @name: name of this subdev, to use in SSR
+ * @ssctl_instance: instance id of the ssctl QMI service
+ *
+ * Return: A new qcom_sysmon object, or NULL on failure
+ */
+struct qcom_sysmon *qcom_add_sysmon_subdev(struct rproc *rproc,
+ const char *name,
+ int ssctl_instance)
+{
+ struct qcom_sysmon *sysmon;
+ int ret;
+
+ sysmon = kzalloc(sizeof(*sysmon), GFP_KERNEL);
+ if (!sysmon)
+ return ERR_PTR(-ENOMEM);
+
+ sysmon->dev = rproc->dev.parent;
+ sysmon->rproc = rproc;
+
+ sysmon->name = name;
+ sysmon->ssctl_instance = ssctl_instance;
+
+ init_completion(&sysmon->comp);
+ init_completion(&sysmon->ind_comp);
+ init_completion(&sysmon->shutdown_comp);
+ init_completion(&sysmon->ssctl_comp);
+ mutex_init(&sysmon->lock);
+ mutex_init(&sysmon->state_lock);
+
+ sysmon->shutdown_irq = of_irq_get_byname(sysmon->dev->of_node,
+ "shutdown-ack");
+ if (sysmon->shutdown_irq < 0) {
+ if (sysmon->shutdown_irq != -ENODATA) {
+ dev_err(sysmon->dev,
+ "failed to retrieve shutdown-ack IRQ\n");
+ ret = sysmon->shutdown_irq;
+ kfree(sysmon);
+ return ERR_PTR(ret);
+ }
+ } else {
+ ret = devm_request_threaded_irq(sysmon->dev,
+ sysmon->shutdown_irq,
+ NULL, sysmon_shutdown_interrupt,
+ IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+ "q6v5 shutdown-ack", sysmon);
+ if (ret) {
+ dev_err(sysmon->dev,
+ "failed to acquire shutdown-ack IRQ\n");
+ kfree(sysmon);
+ return ERR_PTR(ret);
+ }
+ }
+
+ ret = qmi_handle_init(&sysmon->qmi, SSCTL_MAX_MSG_LEN, &ssctl_ops,
+ qmi_indication_handler);
+ if (ret < 0) {
+ dev_err(sysmon->dev, "failed to initialize qmi handle\n");
+ kfree(sysmon);
+ return ERR_PTR(ret);
+ }
+
+ qmi_add_lookup(&sysmon->qmi, 43, 0, 0);
+
+ sysmon->subdev.prepare = sysmon_prepare;
+ sysmon->subdev.start = sysmon_start;
+ sysmon->subdev.stop = sysmon_stop;
+ sysmon->subdev.unprepare = sysmon_unprepare;
+
+ rproc_add_subdev(rproc, &sysmon->subdev);
+
+ sysmon->nb.notifier_call = sysmon_notify;
+ blocking_notifier_chain_register(&sysmon_notifiers, &sysmon->nb);
+
+ mutex_lock(&sysmon_lock);
+ list_add(&sysmon->node, &sysmon_list);
+ mutex_unlock(&sysmon_lock);
+
+ return sysmon;
+}
+EXPORT_SYMBOL_GPL(qcom_add_sysmon_subdev);
+
+/**
+ * qcom_remove_sysmon_subdev() - release a qcom_sysmon
+ * @sysmon: sysmon context, as retrieved by qcom_add_sysmon_subdev()
+ */
+void qcom_remove_sysmon_subdev(struct qcom_sysmon *sysmon)
+{
+ if (!sysmon)
+ return;
+
+ mutex_lock(&sysmon_lock);
+ list_del(&sysmon->node);
+ mutex_unlock(&sysmon_lock);
+
+ blocking_notifier_chain_unregister(&sysmon_notifiers, &sysmon->nb);
+
+ rproc_remove_subdev(sysmon->rproc, &sysmon->subdev);
+
+ qmi_handle_release(&sysmon->qmi);
+
+ kfree(sysmon);
+}
+EXPORT_SYMBOL_GPL(qcom_remove_sysmon_subdev);
+
+/**
+ * qcom_sysmon_shutdown_acked() - query the success of the last shutdown
+ * @sysmon: sysmon context
+ *
+ * When sysmon is used to request a graceful shutdown of the remote processor
+ * this can be used by the remoteproc driver to query the success, in order to
+ * know if it should fall back to other means of requesting a shutdown.
+ *
+ * Return: boolean indicator of the success of the last shutdown request
+ */
+bool qcom_sysmon_shutdown_acked(struct qcom_sysmon *sysmon)
+{
+ return sysmon && sysmon->shutdown_acked;
+}
+EXPORT_SYMBOL_GPL(qcom_sysmon_shutdown_acked);
+
+/**
+ * sysmon_probe() - probe sys_mon channel
+ * @rpdev: rpmsg device handle
+ *
+ * Find the sysmon context associated with the ancestor remoteproc and assign
+ * this rpmsg device with said sysmon context.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+static int sysmon_probe(struct rpmsg_device *rpdev)
+{
+ struct qcom_sysmon *sysmon;
+ struct rproc *rproc;
+
+ rproc = rproc_get_by_child(&rpdev->dev);
+ if (!rproc) {
+ dev_err(&rpdev->dev, "sysmon device not child of rproc\n");
+ return -EINVAL;
+ }
+
+ mutex_lock(&sysmon_lock);
+ list_for_each_entry(sysmon, &sysmon_list, node) {
+ if (sysmon->rproc == rproc)
+ goto found;
+ }
+ mutex_unlock(&sysmon_lock);
+
+ dev_err(&rpdev->dev, "no sysmon associated with parent rproc\n");
+
+ return -EINVAL;
+
+found:
+ mutex_unlock(&sysmon_lock);
+
+ rpdev->ept->priv = sysmon;
+ sysmon->ept = rpdev->ept;
+
+ return 0;
+}
+
+/**
+ * sysmon_remove() - sys_mon channel remove handler
+ * @rpdev: rpmsg device handle
+ *
+ * Disassociate the rpmsg device with the sysmon instance.
+ */
+static void sysmon_remove(struct rpmsg_device *rpdev)
+{
+ struct qcom_sysmon *sysmon = rpdev->ept->priv;
+
+ sysmon->ept = NULL;
+}
+
+static const struct rpmsg_device_id sysmon_match[] = {
+ { "sys_mon" },
+ {}
+};
+
+static struct rpmsg_driver sysmon_driver = {
+ .probe = sysmon_probe,
+ .remove = sysmon_remove,
+ .callback = sysmon_callback,
+ .id_table = sysmon_match,
+ .drv = {
+ .name = "qcom_sysmon",
+ },
+};
+
+module_rpmsg_driver(sysmon_driver);
+
+MODULE_DESCRIPTION("Qualcomm sysmon driver");
+MODULE_LICENSE("GPL v2");