linux/drivers/soc/qcom/qmi_interface.c

849 lines
21 KiB
C

// 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);