v4.19.13 snapshot.
diff --git a/drivers/soc/qcom/qmi_interface.c b/drivers/soc/qcom/qmi_interface.c
new file mode 100644
index 0000000..938ca41
--- /dev/null
+++ b/drivers/soc/qcom/qmi_interface.c
@@ -0,0 +1,848 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017 Linaro Ltd.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/qrtr.h>
+#include <linux/net.h>
+#include <linux/completion.h>
+#include <linux/idr.h>
+#include <linux/string.h>
+#include <net/sock.h>
+#include <linux/workqueue.h>
+#include <linux/soc/qcom/qmi.h>
+
+static struct socket *qmi_sock_create(struct qmi_handle *qmi,
+ struct sockaddr_qrtr *sq);
+
+/**
+ * qmi_recv_new_server() - handler of NEW_SERVER control message
+ * @qmi: qmi handle
+ * @service: service id of the new server
+ * @instance: instance id of the new server
+ * @node: node of the new server
+ * @port: port of the new server
+ *
+ * Calls the new_server callback to inform the client about a newly registered
+ * server matching the currently registered service lookup.
+ */
+static void qmi_recv_new_server(struct qmi_handle *qmi,
+ unsigned int service, unsigned int instance,
+ unsigned int node, unsigned int port)
+{
+ struct qmi_ops *ops = &qmi->ops;
+ struct qmi_service *svc;
+ int ret;
+
+ if (!ops->new_server)
+ return;
+
+ /* Ignore EOF marker */
+ if (!node && !port)
+ return;
+
+ svc = kzalloc(sizeof(*svc), GFP_KERNEL);
+ if (!svc)
+ return;
+
+ svc->service = service;
+ svc->version = instance & 0xff;
+ svc->instance = instance >> 8;
+ svc->node = node;
+ svc->port = port;
+
+ ret = ops->new_server(qmi, svc);
+ if (ret < 0)
+ kfree(svc);
+ else
+ list_add(&svc->list_node, &qmi->lookup_results);
+}
+
+/**
+ * qmi_recv_del_server() - handler of DEL_SERVER control message
+ * @qmi: qmi handle
+ * @node: node of the dying server, a value of -1 matches all nodes
+ * @port: port of the dying server, a value of -1 matches all ports
+ *
+ * Calls the del_server callback for each previously seen server, allowing the
+ * client to react to the disappearing server.
+ */
+static void qmi_recv_del_server(struct qmi_handle *qmi,
+ unsigned int node, unsigned int port)
+{
+ struct qmi_ops *ops = &qmi->ops;
+ struct qmi_service *svc;
+ struct qmi_service *tmp;
+
+ list_for_each_entry_safe(svc, tmp, &qmi->lookup_results, list_node) {
+ if (node != -1 && svc->node != node)
+ continue;
+ if (port != -1 && svc->port != port)
+ continue;
+
+ if (ops->del_server)
+ ops->del_server(qmi, svc);
+
+ list_del(&svc->list_node);
+ kfree(svc);
+ }
+}
+
+/**
+ * qmi_recv_bye() - handler of BYE control message
+ * @qmi: qmi handle
+ * @node: id of the dying node
+ *
+ * Signals the client that all previously registered services on this node are
+ * now gone and then calls the bye callback to allow the client client further
+ * cleaning up resources associated with this remote.
+ */
+static void qmi_recv_bye(struct qmi_handle *qmi,
+ unsigned int node)
+{
+ struct qmi_ops *ops = &qmi->ops;
+
+ qmi_recv_del_server(qmi, node, -1);
+
+ if (ops->bye)
+ ops->bye(qmi, node);
+}
+
+/**
+ * qmi_recv_del_client() - handler of DEL_CLIENT control message
+ * @qmi: qmi handle
+ * @node: node of the dying client
+ * @port: port of the dying client
+ *
+ * Signals the client about a dying client, by calling the del_client callback.
+ */
+static void qmi_recv_del_client(struct qmi_handle *qmi,
+ unsigned int node, unsigned int port)
+{
+ struct qmi_ops *ops = &qmi->ops;
+
+ if (ops->del_client)
+ ops->del_client(qmi, node, port);
+}
+
+static void qmi_recv_ctrl_pkt(struct qmi_handle *qmi,
+ const void *buf, size_t len)
+{
+ const struct qrtr_ctrl_pkt *pkt = buf;
+
+ if (len < sizeof(struct qrtr_ctrl_pkt)) {
+ pr_debug("ignoring short control packet\n");
+ return;
+ }
+
+ switch (le32_to_cpu(pkt->cmd)) {
+ case QRTR_TYPE_BYE:
+ qmi_recv_bye(qmi, le32_to_cpu(pkt->client.node));
+ break;
+ case QRTR_TYPE_NEW_SERVER:
+ qmi_recv_new_server(qmi,
+ le32_to_cpu(pkt->server.service),
+ le32_to_cpu(pkt->server.instance),
+ le32_to_cpu(pkt->server.node),
+ le32_to_cpu(pkt->server.port));
+ break;
+ case QRTR_TYPE_DEL_SERVER:
+ qmi_recv_del_server(qmi,
+ le32_to_cpu(pkt->server.node),
+ le32_to_cpu(pkt->server.port));
+ break;
+ case QRTR_TYPE_DEL_CLIENT:
+ qmi_recv_del_client(qmi,
+ le32_to_cpu(pkt->client.node),
+ le32_to_cpu(pkt->client.port));
+ break;
+ }
+}
+
+static void qmi_send_new_lookup(struct qmi_handle *qmi, struct qmi_service *svc)
+{
+ struct qrtr_ctrl_pkt pkt;
+ struct sockaddr_qrtr sq;
+ struct msghdr msg = { };
+ struct kvec iv = { &pkt, sizeof(pkt) };
+ int ret;
+
+ memset(&pkt, 0, sizeof(pkt));
+ pkt.cmd = cpu_to_le32(QRTR_TYPE_NEW_LOOKUP);
+ pkt.server.service = cpu_to_le32(svc->service);
+ pkt.server.instance = cpu_to_le32(svc->version | svc->instance << 8);
+
+ sq.sq_family = qmi->sq.sq_family;
+ sq.sq_node = qmi->sq.sq_node;
+ sq.sq_port = QRTR_PORT_CTRL;
+
+ msg.msg_name = &sq;
+ msg.msg_namelen = sizeof(sq);
+
+ mutex_lock(&qmi->sock_lock);
+ if (qmi->sock) {
+ ret = kernel_sendmsg(qmi->sock, &msg, &iv, 1, sizeof(pkt));
+ if (ret < 0)
+ pr_err("failed to send lookup registration: %d\n", ret);
+ }
+ mutex_unlock(&qmi->sock_lock);
+}
+
+/**
+ * qmi_add_lookup() - register a new lookup with the name service
+ * @qmi: qmi handle
+ * @service: service id of the request
+ * @instance: instance id of the request
+ * @version: version number of the request
+ *
+ * Registering a lookup query with the name server will cause the name server
+ * to send NEW_SERVER and DEL_SERVER control messages to this socket as
+ * matching services are registered.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int qmi_add_lookup(struct qmi_handle *qmi, unsigned int service,
+ unsigned int version, unsigned int instance)
+{
+ struct qmi_service *svc;
+
+ svc = kzalloc(sizeof(*svc), GFP_KERNEL);
+ if (!svc)
+ return -ENOMEM;
+
+ svc->service = service;
+ svc->version = version;
+ svc->instance = instance;
+
+ list_add(&svc->list_node, &qmi->lookups);
+
+ qmi_send_new_lookup(qmi, svc);
+
+ return 0;
+}
+EXPORT_SYMBOL(qmi_add_lookup);
+
+static void qmi_send_new_server(struct qmi_handle *qmi, struct qmi_service *svc)
+{
+ struct qrtr_ctrl_pkt pkt;
+ struct sockaddr_qrtr sq;
+ struct msghdr msg = { };
+ struct kvec iv = { &pkt, sizeof(pkt) };
+ int ret;
+
+ memset(&pkt, 0, sizeof(pkt));
+ pkt.cmd = cpu_to_le32(QRTR_TYPE_NEW_SERVER);
+ pkt.server.service = cpu_to_le32(svc->service);
+ pkt.server.instance = cpu_to_le32(svc->version | svc->instance << 8);
+ pkt.server.node = cpu_to_le32(qmi->sq.sq_node);
+ pkt.server.port = cpu_to_le32(qmi->sq.sq_port);
+
+ sq.sq_family = qmi->sq.sq_family;
+ sq.sq_node = qmi->sq.sq_node;
+ sq.sq_port = QRTR_PORT_CTRL;
+
+ msg.msg_name = &sq;
+ msg.msg_namelen = sizeof(sq);
+
+ mutex_lock(&qmi->sock_lock);
+ if (qmi->sock) {
+ ret = kernel_sendmsg(qmi->sock, &msg, &iv, 1, sizeof(pkt));
+ if (ret < 0)
+ pr_err("send service registration failed: %d\n", ret);
+ }
+ mutex_unlock(&qmi->sock_lock);
+}
+
+/**
+ * qmi_add_server() - register a service with the name service
+ * @qmi: qmi handle
+ * @service: type of the service
+ * @instance: instance of the service
+ * @version: version of the service
+ *
+ * Register a new service with the name service. This allows clients to find
+ * and start sending messages to the client associated with @qmi.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int qmi_add_server(struct qmi_handle *qmi, unsigned int service,
+ unsigned int version, unsigned int instance)
+{
+ struct qmi_service *svc;
+
+ svc = kzalloc(sizeof(*svc), GFP_KERNEL);
+ if (!svc)
+ return -ENOMEM;
+
+ svc->service = service;
+ svc->version = version;
+ svc->instance = instance;
+
+ list_add(&svc->list_node, &qmi->services);
+
+ qmi_send_new_server(qmi, svc);
+
+ return 0;
+}
+EXPORT_SYMBOL(qmi_add_server);
+
+/**
+ * qmi_txn_init() - allocate transaction id within the given QMI handle
+ * @qmi: QMI handle
+ * @txn: transaction context
+ * @ei: description of how to decode a matching response (optional)
+ * @c_struct: pointer to the object to decode the response into (optional)
+ *
+ * This allocates a transaction id within the QMI handle. If @ei and @c_struct
+ * are specified any responses to this transaction will be decoded as described
+ * by @ei into @c_struct.
+ *
+ * A client calling qmi_txn_init() must call either qmi_txn_wait() or
+ * qmi_txn_cancel() to free up the allocated resources.
+ *
+ * Return: Transaction id on success, negative errno on failure.
+ */
+int qmi_txn_init(struct qmi_handle *qmi, struct qmi_txn *txn,
+ struct qmi_elem_info *ei, void *c_struct)
+{
+ int ret;
+
+ memset(txn, 0, sizeof(*txn));
+
+ mutex_init(&txn->lock);
+ init_completion(&txn->completion);
+ txn->qmi = qmi;
+ txn->ei = ei;
+ txn->dest = c_struct;
+
+ mutex_lock(&qmi->txn_lock);
+ ret = idr_alloc_cyclic(&qmi->txns, txn, 0, INT_MAX, GFP_KERNEL);
+ if (ret < 0)
+ pr_err("failed to allocate transaction id\n");
+
+ txn->id = ret;
+ mutex_unlock(&qmi->txn_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(qmi_txn_init);
+
+/**
+ * qmi_txn_wait() - wait for a response on a transaction
+ * @txn: transaction handle
+ * @timeout: timeout, in jiffies
+ *
+ * If the transaction is decoded by the means of @ei and @c_struct the return
+ * value will be the returned value of qmi_decode_message(), otherwise it's up
+ * to the specified message handler to fill out the result.
+ *
+ * Return: the transaction response on success, negative errno on failure.
+ */
+int qmi_txn_wait(struct qmi_txn *txn, unsigned long timeout)
+{
+ struct qmi_handle *qmi = txn->qmi;
+ int ret;
+
+ ret = wait_for_completion_interruptible_timeout(&txn->completion,
+ timeout);
+
+ mutex_lock(&qmi->txn_lock);
+ mutex_lock(&txn->lock);
+ idr_remove(&qmi->txns, txn->id);
+ mutex_unlock(&txn->lock);
+ mutex_unlock(&qmi->txn_lock);
+
+ if (ret < 0)
+ return ret;
+ else if (ret == 0)
+ return -ETIMEDOUT;
+ else
+ return txn->result;
+}
+EXPORT_SYMBOL(qmi_txn_wait);
+
+/**
+ * qmi_txn_cancel() - cancel an ongoing transaction
+ * @txn: transaction id
+ */
+void qmi_txn_cancel(struct qmi_txn *txn)
+{
+ struct qmi_handle *qmi = txn->qmi;
+
+ mutex_lock(&qmi->txn_lock);
+ mutex_lock(&txn->lock);
+ idr_remove(&qmi->txns, txn->id);
+ mutex_unlock(&txn->lock);
+ mutex_unlock(&qmi->txn_lock);
+}
+EXPORT_SYMBOL(qmi_txn_cancel);
+
+/**
+ * qmi_invoke_handler() - find and invoke a handler for a message
+ * @qmi: qmi handle
+ * @sq: sockaddr of the sender
+ * @txn: transaction object for the message
+ * @buf: buffer containing the message
+ * @len: length of @buf
+ *
+ * Find handler and invoke handler for the incoming message.
+ */
+static void qmi_invoke_handler(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+ struct qmi_txn *txn, const void *buf, size_t len)
+{
+ const struct qmi_msg_handler *handler;
+ const struct qmi_header *hdr = buf;
+ void *dest;
+ int ret;
+
+ if (!qmi->handlers)
+ return;
+
+ for (handler = qmi->handlers; handler->fn; handler++) {
+ if (handler->type == hdr->type &&
+ handler->msg_id == hdr->msg_id)
+ break;
+ }
+
+ if (!handler->fn)
+ return;
+
+ dest = kzalloc(handler->decoded_size, GFP_KERNEL);
+ if (!dest)
+ return;
+
+ ret = qmi_decode_message(buf, len, handler->ei, dest);
+ if (ret < 0)
+ pr_err("failed to decode incoming message\n");
+ else
+ handler->fn(qmi, sq, txn, dest);
+
+ kfree(dest);
+}
+
+/**
+ * qmi_handle_net_reset() - invoked to handle ENETRESET on a QMI handle
+ * @qmi: the QMI context
+ *
+ * As a result of registering a name service with the QRTR all open sockets are
+ * flagged with ENETRESET and this function will be called. The typical case is
+ * the initial boot, where this signals that the local node id has been
+ * configured and as such any bound sockets needs to be rebound. So close the
+ * socket, inform the client and re-initialize the socket.
+ *
+ * For clients it's generally sufficient to react to the del_server callbacks,
+ * but server code is expected to treat the net_reset callback as a "bye" from
+ * all nodes.
+ *
+ * Finally the QMI handle will send out registration requests for any lookups
+ * and services.
+ */
+static void qmi_handle_net_reset(struct qmi_handle *qmi)
+{
+ struct sockaddr_qrtr sq;
+ struct qmi_service *svc;
+ struct socket *sock;
+
+ sock = qmi_sock_create(qmi, &sq);
+ if (IS_ERR(sock))
+ return;
+
+ mutex_lock(&qmi->sock_lock);
+ sock_release(qmi->sock);
+ qmi->sock = NULL;
+ mutex_unlock(&qmi->sock_lock);
+
+ qmi_recv_del_server(qmi, -1, -1);
+
+ if (qmi->ops.net_reset)
+ qmi->ops.net_reset(qmi);
+
+ mutex_lock(&qmi->sock_lock);
+ qmi->sock = sock;
+ qmi->sq = sq;
+ mutex_unlock(&qmi->sock_lock);
+
+ list_for_each_entry(svc, &qmi->lookups, list_node)
+ qmi_send_new_lookup(qmi, svc);
+
+ list_for_each_entry(svc, &qmi->services, list_node)
+ qmi_send_new_server(qmi, svc);
+}
+
+static void qmi_handle_message(struct qmi_handle *qmi,
+ struct sockaddr_qrtr *sq,
+ const void *buf, size_t len)
+{
+ const struct qmi_header *hdr;
+ struct qmi_txn tmp_txn;
+ struct qmi_txn *txn = NULL;
+ int ret;
+
+ if (len < sizeof(*hdr)) {
+ pr_err("ignoring short QMI packet\n");
+ return;
+ }
+
+ hdr = buf;
+
+ /* If this is a response, find the matching transaction handle */
+ if (hdr->type == QMI_RESPONSE) {
+ mutex_lock(&qmi->txn_lock);
+ txn = idr_find(&qmi->txns, hdr->txn_id);
+
+ /* Ignore unexpected responses */
+ if (!txn) {
+ mutex_unlock(&qmi->txn_lock);
+ return;
+ }
+
+ mutex_lock(&txn->lock);
+ mutex_unlock(&qmi->txn_lock);
+
+ if (txn->dest && txn->ei) {
+ ret = qmi_decode_message(buf, len, txn->ei, txn->dest);
+ if (ret < 0)
+ pr_err("failed to decode incoming message\n");
+
+ txn->result = ret;
+ complete(&txn->completion);
+ } else {
+ qmi_invoke_handler(qmi, sq, txn, buf, len);
+ }
+
+ mutex_unlock(&txn->lock);
+ } else {
+ /* Create a txn based on the txn_id of the incoming message */
+ memset(&tmp_txn, 0, sizeof(tmp_txn));
+ tmp_txn.id = hdr->txn_id;
+
+ qmi_invoke_handler(qmi, sq, &tmp_txn, buf, len);
+ }
+}
+
+static void qmi_data_ready_work(struct work_struct *work)
+{
+ struct qmi_handle *qmi = container_of(work, struct qmi_handle, work);
+ struct qmi_ops *ops = &qmi->ops;
+ struct sockaddr_qrtr sq;
+ struct msghdr msg = { .msg_name = &sq, .msg_namelen = sizeof(sq) };
+ struct kvec iv;
+ ssize_t msglen;
+
+ for (;;) {
+ iv.iov_base = qmi->recv_buf;
+ iv.iov_len = qmi->recv_buf_size;
+
+ mutex_lock(&qmi->sock_lock);
+ if (qmi->sock)
+ msglen = kernel_recvmsg(qmi->sock, &msg, &iv, 1,
+ iv.iov_len, MSG_DONTWAIT);
+ else
+ msglen = -EPIPE;
+ mutex_unlock(&qmi->sock_lock);
+ if (msglen == -EAGAIN)
+ break;
+
+ if (msglen == -ENETRESET) {
+ qmi_handle_net_reset(qmi);
+
+ /* The old qmi->sock is gone, our work is done */
+ break;
+ }
+
+ if (msglen < 0) {
+ pr_err("qmi recvmsg failed: %zd\n", msglen);
+ break;
+ }
+
+ if (sq.sq_node == qmi->sq.sq_node &&
+ sq.sq_port == QRTR_PORT_CTRL) {
+ qmi_recv_ctrl_pkt(qmi, qmi->recv_buf, msglen);
+ } else if (ops->msg_handler) {
+ ops->msg_handler(qmi, &sq, qmi->recv_buf, msglen);
+ } else {
+ qmi_handle_message(qmi, &sq, qmi->recv_buf, msglen);
+ }
+ }
+}
+
+static void qmi_data_ready(struct sock *sk)
+{
+ struct qmi_handle *qmi = sk->sk_user_data;
+
+ /*
+ * This will be NULL if we receive data while being in
+ * qmi_handle_release()
+ */
+ if (!qmi)
+ return;
+
+ queue_work(qmi->wq, &qmi->work);
+}
+
+static struct socket *qmi_sock_create(struct qmi_handle *qmi,
+ struct sockaddr_qrtr *sq)
+{
+ struct socket *sock;
+ int ret;
+
+ ret = sock_create_kern(&init_net, AF_QIPCRTR, SOCK_DGRAM,
+ PF_QIPCRTR, &sock);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ ret = kernel_getsockname(sock, (struct sockaddr *)sq);
+ if (ret < 0) {
+ sock_release(sock);
+ return ERR_PTR(ret);
+ }
+
+ sock->sk->sk_user_data = qmi;
+ sock->sk->sk_data_ready = qmi_data_ready;
+ sock->sk->sk_error_report = qmi_data_ready;
+
+ return sock;
+}
+
+/**
+ * qmi_handle_init() - initialize a QMI client handle
+ * @qmi: QMI handle to initialize
+ * @recv_buf_size: maximum size of incoming message
+ * @ops: reference to callbacks for QRTR notifications
+ * @handlers: NULL-terminated list of QMI message handlers
+ *
+ * This initializes the QMI client handle to allow sending and receiving QMI
+ * messages. As messages are received the appropriate handler will be invoked.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int qmi_handle_init(struct qmi_handle *qmi, size_t recv_buf_size,
+ const struct qmi_ops *ops,
+ const struct qmi_msg_handler *handlers)
+{
+ int ret;
+
+ mutex_init(&qmi->txn_lock);
+ mutex_init(&qmi->sock_lock);
+
+ idr_init(&qmi->txns);
+
+ INIT_LIST_HEAD(&qmi->lookups);
+ INIT_LIST_HEAD(&qmi->lookup_results);
+ INIT_LIST_HEAD(&qmi->services);
+
+ INIT_WORK(&qmi->work, qmi_data_ready_work);
+
+ qmi->handlers = handlers;
+ if (ops)
+ qmi->ops = *ops;
+
+ /* Make room for the header */
+ recv_buf_size += sizeof(struct qmi_header);
+ /* Must also be sufficient to hold a control packet */
+ if (recv_buf_size < sizeof(struct qrtr_ctrl_pkt))
+ recv_buf_size = sizeof(struct qrtr_ctrl_pkt);
+
+ qmi->recv_buf_size = recv_buf_size;
+ qmi->recv_buf = kzalloc(recv_buf_size, GFP_KERNEL);
+ if (!qmi->recv_buf)
+ return -ENOMEM;
+
+ qmi->wq = alloc_workqueue("qmi_msg_handler", WQ_UNBOUND, 1);
+ if (!qmi->wq) {
+ ret = -ENOMEM;
+ goto err_free_recv_buf;
+ }
+
+ qmi->sock = qmi_sock_create(qmi, &qmi->sq);
+ if (IS_ERR(qmi->sock)) {
+ pr_err("failed to create QMI socket\n");
+ ret = PTR_ERR(qmi->sock);
+ goto err_destroy_wq;
+ }
+
+ return 0;
+
+err_destroy_wq:
+ destroy_workqueue(qmi->wq);
+err_free_recv_buf:
+ kfree(qmi->recv_buf);
+
+ return ret;
+}
+EXPORT_SYMBOL(qmi_handle_init);
+
+/**
+ * qmi_handle_release() - release the QMI client handle
+ * @qmi: QMI client handle
+ *
+ * This closes the underlying socket and stops any handling of QMI messages.
+ */
+void qmi_handle_release(struct qmi_handle *qmi)
+{
+ struct socket *sock = qmi->sock;
+ struct qmi_service *svc, *tmp;
+
+ sock->sk->sk_user_data = NULL;
+ cancel_work_sync(&qmi->work);
+
+ qmi_recv_del_server(qmi, -1, -1);
+
+ mutex_lock(&qmi->sock_lock);
+ sock_release(sock);
+ qmi->sock = NULL;
+ mutex_unlock(&qmi->sock_lock);
+
+ destroy_workqueue(qmi->wq);
+
+ idr_destroy(&qmi->txns);
+
+ kfree(qmi->recv_buf);
+
+ /* Free registered lookup requests */
+ list_for_each_entry_safe(svc, tmp, &qmi->lookups, list_node) {
+ list_del(&svc->list_node);
+ kfree(svc);
+ }
+
+ /* Free registered service information */
+ list_for_each_entry_safe(svc, tmp, &qmi->services, list_node) {
+ list_del(&svc->list_node);
+ kfree(svc);
+ }
+}
+EXPORT_SYMBOL(qmi_handle_release);
+
+/**
+ * qmi_send_message() - send a QMI message
+ * @qmi: QMI client handle
+ * @sq: destination sockaddr
+ * @txn: transaction object to use for the message
+ * @type: type of message to send
+ * @msg_id: message id
+ * @len: max length of the QMI message
+ * @ei: QMI message description
+ * @c_struct: object to be encoded
+ *
+ * This function encodes @c_struct using @ei into a message of type @type,
+ * with @msg_id and @txn into a buffer of maximum size @len, and sends this to
+ * @sq.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+static ssize_t qmi_send_message(struct qmi_handle *qmi,
+ struct sockaddr_qrtr *sq, struct qmi_txn *txn,
+ int type, int msg_id, size_t len,
+ struct qmi_elem_info *ei, const void *c_struct)
+{
+ struct msghdr msghdr = {};
+ struct kvec iv;
+ void *msg;
+ int ret;
+
+ msg = qmi_encode_message(type,
+ msg_id, &len,
+ txn->id, ei,
+ c_struct);
+ if (IS_ERR(msg))
+ return PTR_ERR(msg);
+
+ iv.iov_base = msg;
+ iv.iov_len = len;
+
+ if (sq) {
+ msghdr.msg_name = sq;
+ msghdr.msg_namelen = sizeof(*sq);
+ }
+
+ mutex_lock(&qmi->sock_lock);
+ if (qmi->sock) {
+ ret = kernel_sendmsg(qmi->sock, &msghdr, &iv, 1, len);
+ if (ret < 0)
+ pr_err("failed to send QMI message\n");
+ } else {
+ ret = -EPIPE;
+ }
+ mutex_unlock(&qmi->sock_lock);
+
+ kfree(msg);
+
+ return ret < 0 ? ret : 0;
+}
+
+/**
+ * qmi_send_request() - send a request QMI message
+ * @qmi: QMI client handle
+ * @sq: destination sockaddr
+ * @txn: transaction object to use for the message
+ * @msg_id: message id
+ * @len: max length of the QMI message
+ * @ei: QMI message description
+ * @c_struct: object to be encoded
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+ssize_t qmi_send_request(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+ struct qmi_txn *txn, int msg_id, size_t len,
+ struct qmi_elem_info *ei, const void *c_struct)
+{
+ return qmi_send_message(qmi, sq, txn, QMI_REQUEST, msg_id, len, ei,
+ c_struct);
+}
+EXPORT_SYMBOL(qmi_send_request);
+
+/**
+ * qmi_send_response() - send a response QMI message
+ * @qmi: QMI client handle
+ * @sq: destination sockaddr
+ * @txn: transaction object to use for the message
+ * @msg_id: message id
+ * @len: max length of the QMI message
+ * @ei: QMI message description
+ * @c_struct: object to be encoded
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+ssize_t qmi_send_response(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+ struct qmi_txn *txn, int msg_id, size_t len,
+ struct qmi_elem_info *ei, const void *c_struct)
+{
+ return qmi_send_message(qmi, sq, txn, QMI_RESPONSE, msg_id, len, ei,
+ c_struct);
+}
+EXPORT_SYMBOL(qmi_send_response);
+
+/**
+ * qmi_send_indication() - send an indication QMI message
+ * @qmi: QMI client handle
+ * @sq: destination sockaddr
+ * @msg_id: message id
+ * @len: max length of the QMI message
+ * @ei: QMI message description
+ * @c_struct: object to be encoded
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+ssize_t qmi_send_indication(struct qmi_handle *qmi, struct sockaddr_qrtr *sq,
+ int msg_id, size_t len, struct qmi_elem_info *ei,
+ const void *c_struct)
+{
+ struct qmi_txn txn;
+ ssize_t rval;
+ int ret;
+
+ ret = qmi_txn_init(qmi, &txn, NULL, NULL);
+ if (ret < 0)
+ return ret;
+
+ rval = qmi_send_message(qmi, sq, &txn, QMI_INDICATION, msg_id, len, ei,
+ c_struct);
+
+ /* We don't care about future messages on this txn */
+ qmi_txn_cancel(&txn);
+
+ return rval;
+}
+EXPORT_SYMBOL(qmi_send_indication);