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76371c7c0d8642ef30a865df57bf6d186855802d
android_kernel_xiaomi_sm8450/drivers/misc/mic/scif/scif_api.c
Nikhil Rao 76371c7c0d misc: mic: SCIF connections APIs i.e. accept and connect 
SCIF connection APIs which establish a SCIF connection between
a pair of SCIF endpoints. A SCIF connection consists of a
dedicated queue-pair between the endpoints. Client messages are
sent over the queue-pair whereas the signaling associated with the
message is multiplexed over the node queue-pair. Similarly other
control messages such as exposing registered memory are also sent
over the node queue-pair. The SCIF endpoints must be in connected
state to exchange messages, register memory, map remote memory and
trigger DMA transfers. SCIF connections can be set up
asynchronously or synchronously.

Thanks to Johnnie S Peters for authoring parts of this patch during
early bring up of the SCIF driver.

Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24 12:13:36 -07:00

875 lines
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/*
* Intel MIC Platform Software Stack (MPSS)
*
* Copyright(c) 2014 Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* Intel SCIF driver.
*
*/
#include <linux/scif.h>
#include "scif_main.h"
#include "scif_map.h"
static const char * const scif_ep_states[] = {
"Unbound",
"Bound",
"Listening",
"Connected",
"Connecting",
"Mapping",
"Closing",
"Close Listening",
"Disconnected",
"Zombie"};
enum conn_async_state {
ASYNC_CONN_IDLE = 1, /* ep setup for async connect */
ASYNC_CONN_INPROGRESS, /* async connect in progress */
ASYNC_CONN_FLUSH_WORK /* async work flush in progress */
};
scif_epd_t scif_open(void)
{
struct scif_endpt *ep;
might_sleep();
ep = kzalloc(sizeof(*ep), GFP_KERNEL);
if (!ep)
goto err_ep_alloc;
ep->qp_info.qp = kzalloc(sizeof(*ep->qp_info.qp), GFP_KERNEL);
if (!ep->qp_info.qp)
goto err_qp_alloc;
spin_lock_init(&ep->lock);
mutex_init(&ep->sendlock);
mutex_init(&ep->recvlock);
ep->state = SCIFEP_UNBOUND;
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI open: ep %p success\n", ep);
return ep;
err_qp_alloc:
kfree(ep);
err_ep_alloc:
return NULL;
}
EXPORT_SYMBOL_GPL(scif_open);
/*
* scif_disconnect_ep - Disconnects the endpoint if found
* @epd: The end point returned from scif_open()
*/
static struct scif_endpt *scif_disconnect_ep(struct scif_endpt *ep)
{
struct scifmsg msg;
struct scif_endpt *fep = NULL;
struct scif_endpt *tmpep;
struct list_head *pos, *tmpq;
int err;
/*
* Wake up any threads blocked in send()/recv() before closing
* out the connection. Grabbing and releasing the send/recv lock
* will ensure that any blocked senders/receivers have exited for
* Ring 0 endpoints. It is a Ring 0 bug to call send/recv after
* close. Ring 3 endpoints are not affected since close will not
* be called while there are IOCTLs executing.
*/
wake_up_interruptible(&ep->sendwq);
wake_up_interruptible(&ep->recvwq);
mutex_lock(&ep->sendlock);
mutex_unlock(&ep->sendlock);
mutex_lock(&ep->recvlock);
mutex_unlock(&ep->recvlock);
/* Remove from the connected list */
mutex_lock(&scif_info.connlock);
list_for_each_safe(pos, tmpq, &scif_info.connected) {
tmpep = list_entry(pos, struct scif_endpt, list);
if (tmpep == ep) {
list_del(pos);
fep = tmpep;
spin_lock(&ep->lock);
break;
}
}
if (!fep) {
/*
* The other side has completed the disconnect before
* the end point can be removed from the list. Therefore
* the ep lock is not locked, traverse the disconnected
* list to find the endpoint and release the conn lock.
*/
list_for_each_safe(pos, tmpq, &scif_info.disconnected) {
tmpep = list_entry(pos, struct scif_endpt, list);
if (tmpep == ep) {
list_del(pos);
break;
}
}
mutex_unlock(&scif_info.connlock);
return NULL;
}
init_completion(&ep->discon);
msg.uop = SCIF_DISCNCT;
msg.src = ep->port;
msg.dst = ep->peer;
msg.payload[0] = (u64)ep;
msg.payload[1] = ep->remote_ep;
err = scif_nodeqp_send(ep->remote_dev, &msg);
spin_unlock(&ep->lock);
mutex_unlock(&scif_info.connlock);
if (!err)
/* Wait for the remote node to respond with SCIF_DISCNT_ACK */
wait_for_completion_timeout(&ep->discon,
SCIF_NODE_ALIVE_TIMEOUT);
return ep;
}
int scif_close(scif_epd_t epd)
{
struct scif_endpt *ep = (struct scif_endpt *)epd;
struct scif_endpt *tmpep;
struct list_head *pos, *tmpq;
enum scif_epd_state oldstate;
bool flush_conn;
dev_dbg(scif_info.mdev.this_device, "SCIFAPI close: ep %p %s\n",
ep, scif_ep_states[ep->state]);
might_sleep();
spin_lock(&ep->lock);
flush_conn = (ep->conn_async_state == ASYNC_CONN_INPROGRESS);
spin_unlock(&ep->lock);
if (flush_conn)
flush_work(&scif_info.conn_work);
spin_lock(&ep->lock);
oldstate = ep->state;
ep->state = SCIFEP_CLOSING;
switch (oldstate) {
case SCIFEP_ZOMBIE:
case SCIFEP_DISCONNECTED:
spin_unlock(&ep->lock);
/* Remove from the disconnected list */
mutex_lock(&scif_info.connlock);
list_for_each_safe(pos, tmpq, &scif_info.disconnected) {
tmpep = list_entry(pos, struct scif_endpt, list);
if (tmpep == ep) {
list_del(pos);
break;
}
}
mutex_unlock(&scif_info.connlock);
break;
case SCIFEP_UNBOUND:
case SCIFEP_BOUND:
case SCIFEP_CONNECTING:
spin_unlock(&ep->lock);
break;
case SCIFEP_MAPPING:
case SCIFEP_CONNECTED:
case SCIFEP_CLOSING:
{
spin_unlock(&ep->lock);
scif_disconnect_ep(ep);
break;
}
case SCIFEP_LISTENING:
case SCIFEP_CLLISTEN:
{
struct scif_conreq *conreq;
struct scifmsg msg;
struct scif_endpt *aep;
spin_unlock(&ep->lock);
spin_lock(&scif_info.eplock);
/* remove from listen list */
list_for_each_safe(pos, tmpq, &scif_info.listen) {
tmpep = list_entry(pos, struct scif_endpt, list);
if (tmpep == ep)
list_del(pos);
}
/* Remove any dangling accepts */
while (ep->acceptcnt) {
aep = list_first_entry(&ep->li_accept,
struct scif_endpt, liacceptlist);
list_del(&aep->liacceptlist);
scif_put_port(aep->port.port);
list_for_each_safe(pos, tmpq, &scif_info.uaccept) {
tmpep = list_entry(pos, struct scif_endpt,
miacceptlist);
if (tmpep == aep) {
list_del(pos);
break;
}
}
spin_unlock(&scif_info.eplock);
mutex_lock(&scif_info.connlock);
list_for_each_safe(pos, tmpq, &scif_info.connected) {
tmpep = list_entry(pos,
struct scif_endpt, list);
if (tmpep == aep) {
list_del(pos);
break;
}
}
list_for_each_safe(pos, tmpq, &scif_info.disconnected) {
tmpep = list_entry(pos,
struct scif_endpt, list);
if (tmpep == aep) {
list_del(pos);
break;
}
}
mutex_unlock(&scif_info.connlock);
scif_teardown_ep(aep);
spin_lock(&scif_info.eplock);
scif_add_epd_to_zombie_list(aep, SCIF_EPLOCK_HELD);
ep->acceptcnt--;
}
spin_lock(&ep->lock);
spin_unlock(&scif_info.eplock);
/* Remove and reject any pending connection requests. */
while (ep->conreqcnt) {
conreq = list_first_entry(&ep->conlist,
struct scif_conreq, list);
list_del(&conreq->list);
msg.uop = SCIF_CNCT_REJ;
msg.dst.node = conreq->msg.src.node;
msg.dst.port = conreq->msg.src.port;
msg.payload[0] = conreq->msg.payload[0];
msg.payload[1] = conreq->msg.payload[1];
/*
* No Error Handling on purpose for scif_nodeqp_send().
* If the remote node is lost we still want free the
* connection requests on the self node.
*/
scif_nodeqp_send(&scif_dev[conreq->msg.src.node],
&msg);
ep->conreqcnt--;
kfree(conreq);
}
spin_unlock(&ep->lock);
/* If a kSCIF accept is waiting wake it up */
wake_up_interruptible(&ep->conwq);
break;
}
}
scif_put_port(ep->port.port);
scif_teardown_ep(ep);
scif_add_epd_to_zombie_list(ep, !SCIF_EPLOCK_HELD);
return 0;
}
EXPORT_SYMBOL_GPL(scif_close);
/**
* scif_flush() - Wakes up any blocking accepts. The endpoint will no longer
* accept new connections.
* @epd: The end point returned from scif_open()
*/
int __scif_flush(scif_epd_t epd)
{
struct scif_endpt *ep = (struct scif_endpt *)epd;
switch (ep->state) {
case SCIFEP_LISTENING:
{
ep->state = SCIFEP_CLLISTEN;
/* If an accept is waiting wake it up */
wake_up_interruptible(&ep->conwq);
break;
}
default:
break;
}
return 0;
}
int scif_bind(scif_epd_t epd, u16 pn)
{
struct scif_endpt *ep = (struct scif_endpt *)epd;
int ret = 0;
int tmp;
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI bind: ep %p %s requested port number %d\n",
ep, scif_ep_states[ep->state], pn);
if (pn) {
/*
* Similar to IETF RFC 1700, SCIF ports below
* SCIF_ADMIN_PORT_END can only be bound by system (or root)
* processes or by processes executed by privileged users.
*/
if (pn < SCIF_ADMIN_PORT_END && !capable(CAP_SYS_ADMIN)) {
ret = -EACCES;
goto scif_bind_admin_exit;
}
}
spin_lock(&ep->lock);
if (ep->state == SCIFEP_BOUND) {
ret = -EINVAL;
goto scif_bind_exit;
} else if (ep->state != SCIFEP_UNBOUND) {
ret = -EISCONN;
goto scif_bind_exit;
}
if (pn) {
tmp = scif_rsrv_port(pn);
if (tmp != pn) {
ret = -EINVAL;
goto scif_bind_exit;
}
} else {
pn = scif_get_new_port();
if (!pn) {
ret = -ENOSPC;
goto scif_bind_exit;
}
}
ep->state = SCIFEP_BOUND;
ep->port.node = scif_info.nodeid;
ep->port.port = pn;
ep->conn_async_state = ASYNC_CONN_IDLE;
ret = pn;
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI bind: bound to port number %d\n", pn);
scif_bind_exit:
spin_unlock(&ep->lock);
scif_bind_admin_exit:
return ret;
}
EXPORT_SYMBOL_GPL(scif_bind);
int scif_listen(scif_epd_t epd, int backlog)
{
struct scif_endpt *ep = (struct scif_endpt *)epd;
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI listen: ep %p %s\n", ep, scif_ep_states[ep->state]);
spin_lock(&ep->lock);
switch (ep->state) {
case SCIFEP_ZOMBIE:
case SCIFEP_CLOSING:
case SCIFEP_CLLISTEN:
case SCIFEP_UNBOUND:
case SCIFEP_DISCONNECTED:
spin_unlock(&ep->lock);
return -EINVAL;
case SCIFEP_LISTENING:
case SCIFEP_CONNECTED:
case SCIFEP_CONNECTING:
case SCIFEP_MAPPING:
spin_unlock(&ep->lock);
return -EISCONN;
case SCIFEP_BOUND:
break;
}
ep->state = SCIFEP_LISTENING;
ep->backlog = backlog;
ep->conreqcnt = 0;
ep->acceptcnt = 0;
INIT_LIST_HEAD(&ep->conlist);
init_waitqueue_head(&ep->conwq);
INIT_LIST_HEAD(&ep->li_accept);
spin_unlock(&ep->lock);
/*
* Listen status is complete so delete the qp information not needed
* on a listen before placing on the list of listening ep's
*/
scif_teardown_ep(ep);
ep->qp_info.qp = NULL;
spin_lock(&scif_info.eplock);
list_add_tail(&ep->list, &scif_info.listen);
spin_unlock(&scif_info.eplock);
return 0;
}
EXPORT_SYMBOL_GPL(scif_listen);
/*
************************************************************************
* SCIF connection flow:
*
* 1) A SCIF listening endpoint can call scif_accept(..) to wait for SCIF
* connections via a SCIF_CNCT_REQ message
* 2) A SCIF endpoint can initiate a SCIF connection by calling
* scif_connect(..) which calls scif_setup_qp_connect(..) which
* allocates the local qp for the endpoint ring buffer and then sends
* a SCIF_CNCT_REQ to the remote node and waits for a SCIF_CNCT_GNT or
* a SCIF_CNCT_REJ message
* 3) The peer node handles a SCIF_CNCT_REQ via scif_cnctreq_resp(..) which
* wakes up any threads blocked in step 1 or sends a SCIF_CNCT_REJ
* message otherwise
* 4) A thread blocked waiting for incoming connections allocates its local
* endpoint QP and ring buffer following which it sends a SCIF_CNCT_GNT
* and waits for a SCIF_CNCT_GNT(N)ACK. If the allocation fails then
* the node sends a SCIF_CNCT_REJ message
* 5) Upon receipt of a SCIF_CNCT_GNT or a SCIF_CNCT_REJ message the
* connecting endpoint is woken up as part of handling
* scif_cnctgnt_resp(..) following which it maps the remote endpoints'
* QP, updates its outbound QP and sends a SCIF_CNCT_GNTACK message on
* success or a SCIF_CNCT_GNTNACK message on failure and completes
* the scif_connect(..) API
* 6) Upon receipt of a SCIF_CNCT_GNT(N)ACK the accepting endpoint blocked
* in step 4 is woken up and completes the scif_accept(..) API
* 7) The SCIF connection is now established between the two SCIF endpoints.
*/
static int scif_conn_func(struct scif_endpt *ep)
{
int err = 0;
struct scifmsg msg;
struct device *spdev;
/* Initiate the first part of the endpoint QP setup */
err = scif_setup_qp_connect(ep->qp_info.qp, &ep->qp_info.qp_offset,
SCIF_ENDPT_QP_SIZE, ep->remote_dev);
if (err) {
dev_err(&ep->remote_dev->sdev->dev,
"%s err %d qp_offset 0x%llx\n",
__func__, err, ep->qp_info.qp_offset);
ep->state = SCIFEP_BOUND;
goto connect_error_simple;
}
spdev = scif_get_peer_dev(ep->remote_dev);
if (IS_ERR(spdev)) {
err = PTR_ERR(spdev);
goto cleanup_qp;
}
/* Format connect message and send it */
msg.src = ep->port;
msg.dst = ep->conn_port;
msg.uop = SCIF_CNCT_REQ;
msg.payload[0] = (u64)ep;
msg.payload[1] = ep->qp_info.qp_offset;
err = _scif_nodeqp_send(ep->remote_dev, &msg);
if (err)
goto connect_error_dec;
scif_put_peer_dev(spdev);
/*
* Wait for the remote node to respond with SCIF_CNCT_GNT or
* SCIF_CNCT_REJ message.
*/
err = wait_event_timeout(ep->conwq, ep->state != SCIFEP_CONNECTING,
SCIF_NODE_ALIVE_TIMEOUT);
if (!err) {
dev_err(&ep->remote_dev->sdev->dev,
"%s %d timeout\n", __func__, __LINE__);
ep->state = SCIFEP_BOUND;
}
spdev = scif_get_peer_dev(ep->remote_dev);
if (IS_ERR(spdev)) {
err = PTR_ERR(spdev);
goto cleanup_qp;
}
if (ep->state == SCIFEP_MAPPING) {
err = scif_setup_qp_connect_response(ep->remote_dev,
ep->qp_info.qp,
ep->qp_info.gnt_pld);
/*
* If the resource to map the queue are not available then
* we need to tell the other side to terminate the accept
*/
if (err) {
dev_err(&ep->remote_dev->sdev->dev,
"%s %d err %d\n", __func__, __LINE__, err);
msg.uop = SCIF_CNCT_GNTNACK;
msg.payload[0] = ep->remote_ep;
_scif_nodeqp_send(ep->remote_dev, &msg);
ep->state = SCIFEP_BOUND;
goto connect_error_dec;
}
msg.uop = SCIF_CNCT_GNTACK;
msg.payload[0] = ep->remote_ep;
err = _scif_nodeqp_send(ep->remote_dev, &msg);
if (err) {
ep->state = SCIFEP_BOUND;
goto connect_error_dec;
}
ep->state = SCIFEP_CONNECTED;
mutex_lock(&scif_info.connlock);
list_add_tail(&ep->list, &scif_info.connected);
mutex_unlock(&scif_info.connlock);
dev_dbg(&ep->remote_dev->sdev->dev,
"SCIFAPI connect: ep %p connected\n", ep);
} else if (ep->state == SCIFEP_BOUND) {
dev_dbg(&ep->remote_dev->sdev->dev,
"SCIFAPI connect: ep %p connection refused\n", ep);
err = -ECONNREFUSED;
goto connect_error_dec;
}
scif_put_peer_dev(spdev);
return err;
connect_error_dec:
scif_put_peer_dev(spdev);
cleanup_qp:
scif_cleanup_ep_qp(ep);
connect_error_simple:
return err;
}
/*
* scif_conn_handler:
*
* Workqueue handler for servicing non-blocking SCIF connect
*
*/
void scif_conn_handler(struct work_struct *work)
{
struct scif_endpt *ep;
do {
ep = NULL;
spin_lock(&scif_info.nb_connect_lock);
if (!list_empty(&scif_info.nb_connect_list)) {
ep = list_first_entry(&scif_info.nb_connect_list,
struct scif_endpt, conn_list);
list_del(&ep->conn_list);
}
spin_unlock(&scif_info.nb_connect_lock);
if (ep)
ep->conn_err = scif_conn_func(ep);
} while (ep);
}
int __scif_connect(scif_epd_t epd, struct scif_port_id *dst, bool non_block)
{
struct scif_endpt *ep = (struct scif_endpt *)epd;
int err = 0;
struct scif_dev *remote_dev;
struct device *spdev;
dev_dbg(scif_info.mdev.this_device, "SCIFAPI connect: ep %p %s\n", ep,
scif_ep_states[ep->state]);
if (!scif_dev || dst->node > scif_info.maxid)
return -ENODEV;
might_sleep();
remote_dev = &scif_dev[dst->node];
spdev = scif_get_peer_dev(remote_dev);
if (IS_ERR(spdev)) {
err = PTR_ERR(spdev);
return err;
}
spin_lock(&ep->lock);
switch (ep->state) {
case SCIFEP_ZOMBIE:
case SCIFEP_CLOSING:
err = -EINVAL;
break;
case SCIFEP_DISCONNECTED:
if (ep->conn_async_state == ASYNC_CONN_INPROGRESS)
ep->conn_async_state = ASYNC_CONN_FLUSH_WORK;
else
err = -EINVAL;
break;
case SCIFEP_LISTENING:
case SCIFEP_CLLISTEN:
err = -EOPNOTSUPP;
break;
case SCIFEP_CONNECTING:
case SCIFEP_MAPPING:
if (ep->conn_async_state == ASYNC_CONN_INPROGRESS)
err = -EINPROGRESS;
else
err = -EISCONN;
break;
case SCIFEP_CONNECTED:
if (ep->conn_async_state == ASYNC_CONN_INPROGRESS)
ep->conn_async_state = ASYNC_CONN_FLUSH_WORK;
else
err = -EISCONN;
break;
case SCIFEP_UNBOUND:
ep->port.port = scif_get_new_port();
if (!ep->port.port) {
err = -ENOSPC;
} else {
ep->port.node = scif_info.nodeid;
ep->conn_async_state = ASYNC_CONN_IDLE;
}
/* Fall through */
case SCIFEP_BOUND:
/*
* If a non-blocking connect has been already initiated
* (conn_async_state is either ASYNC_CONN_INPROGRESS or
* ASYNC_CONN_FLUSH_WORK), the end point could end up in
* SCIF_BOUND due an error in the connection process
* (e.g., connection refused) If conn_async_state is
* ASYNC_CONN_INPROGRESS - transition to ASYNC_CONN_FLUSH_WORK
* so that the error status can be collected. If the state is
* already ASYNC_CONN_FLUSH_WORK - then set the error to
* EINPROGRESS since some other thread is waiting to collect
* error status.
*/
if (ep->conn_async_state == ASYNC_CONN_INPROGRESS) {
ep->conn_async_state = ASYNC_CONN_FLUSH_WORK;
} else if (ep->conn_async_state == ASYNC_CONN_FLUSH_WORK) {
err = -EINPROGRESS;
} else {
ep->conn_port = *dst;
init_waitqueue_head(&ep->sendwq);
init_waitqueue_head(&ep->recvwq);
init_waitqueue_head(&ep->conwq);
ep->conn_async_state = 0;
if (unlikely(non_block))
ep->conn_async_state = ASYNC_CONN_INPROGRESS;
}
break;
}
if (err || ep->conn_async_state == ASYNC_CONN_FLUSH_WORK)
goto connect_simple_unlock1;
ep->state = SCIFEP_CONNECTING;
ep->remote_dev = &scif_dev[dst->node];
ep->qp_info.qp->magic = SCIFEP_MAGIC;
if (ep->conn_async_state == ASYNC_CONN_INPROGRESS) {
spin_lock(&scif_info.nb_connect_lock);
list_add_tail(&ep->conn_list, &scif_info.nb_connect_list);
spin_unlock(&scif_info.nb_connect_lock);
err = -EINPROGRESS;
schedule_work(&scif_info.conn_work);
}
connect_simple_unlock1:
spin_unlock(&ep->lock);
scif_put_peer_dev(spdev);
if (err) {
return err;
} else if (ep->conn_async_state == ASYNC_CONN_FLUSH_WORK) {
flush_work(&scif_info.conn_work);
err = ep->conn_err;
spin_lock(&ep->lock);
ep->conn_async_state = ASYNC_CONN_IDLE;
spin_unlock(&ep->lock);
} else {
err = scif_conn_func(ep);
}
return err;
}
int scif_connect(scif_epd_t epd, struct scif_port_id *dst)
{
return __scif_connect(epd, dst, false);
}
EXPORT_SYMBOL_GPL(scif_connect);
/**
* scif_accept() - Accept a connection request from the remote node
*
* The function accepts a connection request from the remote node. Successful
* complete is indicate by a new end point being created and passed back
* to the caller for future reference.
*
* Upon successful complete a zero will be returned and the peer information
* will be filled in.
*
* If the end point is not in the listening state -EINVAL will be returned.
*
* If during the connection sequence resource allocation fails the -ENOMEM
* will be returned.
*
* If the function is called with the ASYNC flag set and no connection requests
* are pending it will return -EAGAIN.
*
* If the remote side is not sending any connection requests the caller may
* terminate this function with a signal. If so a -EINTR will be returned.
*/
int scif_accept(scif_epd_t epd, struct scif_port_id *peer,
scif_epd_t *newepd, int flags)
{
struct scif_endpt *lep = (struct scif_endpt *)epd;
struct scif_endpt *cep;
struct scif_conreq *conreq;
struct scifmsg msg;
int err;
struct device *spdev;
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI accept: ep %p %s\n", lep, scif_ep_states[lep->state]);
if (flags & ~SCIF_ACCEPT_SYNC)
return -EINVAL;
if (!peer || !newepd)
return -EINVAL;
might_sleep();
spin_lock(&lep->lock);
if (lep->state != SCIFEP_LISTENING) {
spin_unlock(&lep->lock);
return -EINVAL;
}
if (!lep->conreqcnt && !(flags & SCIF_ACCEPT_SYNC)) {
/* No connection request present and we do not want to wait */
spin_unlock(&lep->lock);
return -EAGAIN;
}
lep->files = current->files;
retry_connection:
spin_unlock(&lep->lock);
/* Wait for the remote node to send us a SCIF_CNCT_REQ */
err = wait_event_interruptible(lep->conwq,
(lep->conreqcnt ||
(lep->state != SCIFEP_LISTENING)));
if (err)
return err;
if (lep->state != SCIFEP_LISTENING)
return -EINTR;
spin_lock(&lep->lock);
if (!lep->conreqcnt)
goto retry_connection;
/* Get the first connect request off the list */
conreq = list_first_entry(&lep->conlist, struct scif_conreq, list);
list_del(&conreq->list);
lep->conreqcnt--;
spin_unlock(&lep->lock);
/* Fill in the peer information */
peer->node = conreq->msg.src.node;
peer->port = conreq->msg.src.port;
cep = kzalloc(sizeof(*cep), GFP_KERNEL);
if (!cep) {
err = -ENOMEM;
goto scif_accept_error_epalloc;
}
spin_lock_init(&cep->lock);
mutex_init(&cep->sendlock);
mutex_init(&cep->recvlock);
cep->state = SCIFEP_CONNECTING;
cep->remote_dev = &scif_dev[peer->node];
cep->remote_ep = conreq->msg.payload[0];
cep->qp_info.qp = kzalloc(sizeof(*cep->qp_info.qp), GFP_KERNEL);
if (!cep->qp_info.qp) {
err = -ENOMEM;
goto scif_accept_error_qpalloc;
}
cep->qp_info.qp->magic = SCIFEP_MAGIC;
spdev = scif_get_peer_dev(cep->remote_dev);
if (IS_ERR(spdev)) {
err = PTR_ERR(spdev);
goto scif_accept_error_map;
}
err = scif_setup_qp_accept(cep->qp_info.qp, &cep->qp_info.qp_offset,
conreq->msg.payload[1], SCIF_ENDPT_QP_SIZE,
cep->remote_dev);
if (err) {
dev_dbg(&cep->remote_dev->sdev->dev,
"SCIFAPI accept: ep %p new %p scif_setup_qp_accept %d qp_offset 0x%llx\n",
lep, cep, err, cep->qp_info.qp_offset);
scif_put_peer_dev(spdev);
goto scif_accept_error_map;
}
cep->port.node = lep->port.node;
cep->port.port = lep->port.port;
cep->peer.node = peer->node;
cep->peer.port = peer->port;
init_waitqueue_head(&cep->sendwq);
init_waitqueue_head(&cep->recvwq);
init_waitqueue_head(&cep->conwq);
msg.uop = SCIF_CNCT_GNT;
msg.src = cep->port;
msg.payload[0] = cep->remote_ep;
msg.payload[1] = cep->qp_info.qp_offset;
msg.payload[2] = (u64)cep;
err = _scif_nodeqp_send(cep->remote_dev, &msg);
scif_put_peer_dev(spdev);
if (err)
goto scif_accept_error_map;
retry:
/* Wait for the remote node to respond with SCIF_CNCT_GNT(N)ACK */
err = wait_event_timeout(cep->conwq, cep->state != SCIFEP_CONNECTING,
SCIF_NODE_ACCEPT_TIMEOUT);
if (!err && scifdev_alive(cep))
goto retry;
err = !err ? -ENODEV : 0;
if (err)
goto scif_accept_error_map;
kfree(conreq);
spin_lock(&cep->lock);
if (cep->state == SCIFEP_CLOSING) {
/*
* Remote failed to allocate resources and NAKed the grant.
* There is at this point nothing referencing the new end point.
*/
spin_unlock(&cep->lock);
scif_teardown_ep(cep);
kfree(cep);
/* If call with sync flag then go back and wait. */
if (flags & SCIF_ACCEPT_SYNC) {
spin_lock(&lep->lock);
goto retry_connection;
}
return -EAGAIN;
}
scif_get_port(cep->port.port);
*newepd = (scif_epd_t)cep;
spin_unlock(&cep->lock);
return 0;
scif_accept_error_map:
scif_teardown_ep(cep);
scif_accept_error_qpalloc:
kfree(cep);
scif_accept_error_epalloc:
msg.uop = SCIF_CNCT_REJ;
msg.dst.node = conreq->msg.src.node;
msg.dst.port = conreq->msg.src.port;
msg.payload[0] = conreq->msg.payload[0];
msg.payload[1] = conreq->msg.payload[1];
scif_nodeqp_send(&scif_dev[conreq->msg.src.node], &msg);
kfree(conreq);
return err;
}
EXPORT_SYMBOL_GPL(scif_accept);
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