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kernel-fxtec-pro1x/drivers/misc/mic/scif/scif_api.c
Sudeep Dutt d18243293a misc: mic: SCIF RMA nodeqp and minor miscellaneous changes 
This patch adds the SCIF kernel node QP control messages required to
enable SCIF RMAs. Examples of such node QP control messages include
registration, unregistration, remote memory allocation requests,
remote memory unmap and SCIF remote fence requests.

The patch also updates the SCIF driver with minor changes required to
enable SCIF RMAs by adding the new files to the build, initializing
RMA specific information during SCIF endpoint creation, reserving SCIF
DMA channels, initializing SCIF RMA specific global data structures,
adding the IOCTL hooks required for SCIF RMAs and updating RMA
specific debugfs hooks.

Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 12:54:54 +01:00

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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 */
};
/*
* File operations for anonymous inode file associated with a SCIF endpoint,
* used in kernel mode SCIF poll. Kernel mode SCIF poll calls portions of the
* poll API in the kernel and these take in a struct file *. Since a struct
* file is not available to kernel mode SCIF, it uses an anonymous file for
* this purpose.
*/
const struct file_operations scif_anon_fops = {
.owner = THIS_MODULE,
};
scif_epd_t scif_open(void)
{
struct scif_endpt *ep;
int err;
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;
err = scif_anon_inode_getfile(ep);
if (err)
goto err_anon_inode;
spin_lock_init(&ep->lock);
mutex_init(&ep->sendlock);
mutex_init(&ep->recvlock);
scif_rma_ep_init(ep);
ep->state = SCIFEP_UNBOUND;
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI open: ep %p success\n", ep);
return ep;
err_anon_inode:
kfree(ep->qp_info.qp);
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:
dev_err(scif_info.mdev.this_device,
"SCIFAPI close: zombie state unexpected\n");
case SCIFEP_DISCONNECTED:
spin_unlock(&ep->lock);
scif_unregister_all_windows(epd);
/* 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_unregister_all_windows(epd);
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);
mutex_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;
}
}
mutex_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);
mutex_lock(&scif_info.eplock);
scif_add_epd_to_zombie_list(aep, SCIF_EPLOCK_HELD);
ep->acceptcnt--;
}
spin_lock(&ep->lock);
mutex_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_anon_inode_fput(ep);
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;
mutex_lock(&scif_info.eplock);
list_add_tail(&ep->list, &scif_info.listen);
mutex_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;
err = scif_reserve_dma_chan(ep);
if (err) {
dev_err(&ep->remote_dev->sdev->dev,
"%s %d err %d\n", __func__, __LINE__, err);
ep->state = SCIFEP_BOUND;
goto connect_error_simple;
}
/* 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);
wake_up_interruptible(&ep->conn_pend_wq);
}
} 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) {
init_waitqueue_head(&ep->conn_pend_wq);
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];
scif_rma_ep_init(cep);
err = scif_reserve_dma_chan(cep);
if (err) {
dev_err(scif_info.mdev.this_device,
"%s %d err %d\n", __func__, __LINE__, err);
goto scif_accept_error_qpalloc;
}
cep->qp_info.qp = kzalloc(sizeof(*cep->qp_info.qp), GFP_KERNEL);
if (!cep->qp_info.qp) {
err = -ENOMEM;
goto scif_accept_error_qpalloc;
}
err = scif_anon_inode_getfile(cep);
if (err)
goto scif_accept_error_anon_inode;
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_anon_inode_fput(cep);
scif_accept_error_anon_inode:
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);
/*
* scif_msg_param_check:
* @epd: The end point returned from scif_open()
* @len: Length to receive
* @flags: blocking or non blocking
*
* Validate parameters for messaging APIs scif_send(..)/scif_recv(..).
*/
static inline int scif_msg_param_check(scif_epd_t epd, int len, int flags)
{
int ret = -EINVAL;
if (len < 0)
goto err_ret;
if (flags && (!(flags & SCIF_RECV_BLOCK)))
goto err_ret;
ret = 0;
err_ret:
return ret;
}
static int _scif_send(scif_epd_t epd, void *msg, int len, int flags)
{
struct scif_endpt *ep = (struct scif_endpt *)epd;
struct scifmsg notif_msg;
int curr_xfer_len = 0, sent_len = 0, write_count;
int ret = 0;
struct scif_qp *qp = ep->qp_info.qp;
if (flags & SCIF_SEND_BLOCK)
might_sleep();
spin_lock(&ep->lock);
while (sent_len != len && SCIFEP_CONNECTED == ep->state) {
write_count = scif_rb_space(&qp->outbound_q);
if (write_count) {
/* Best effort to send as much data as possible */
curr_xfer_len = min(len - sent_len, write_count);
ret = scif_rb_write(&qp->outbound_q, msg,
curr_xfer_len);
if (ret < 0)
break;
/* Success. Update write pointer */
scif_rb_commit(&qp->outbound_q);
/*
* Send a notification to the peer about the
* produced data message.
*/
notif_msg.src = ep->port;
notif_msg.uop = SCIF_CLIENT_SENT;
notif_msg.payload[0] = ep->remote_ep;
ret = _scif_nodeqp_send(ep->remote_dev, &notif_msg);
if (ret)
break;
sent_len += curr_xfer_len;
msg = msg + curr_xfer_len;
continue;
}
curr_xfer_len = min(len - sent_len, SCIF_ENDPT_QP_SIZE - 1);
/* Not enough RB space. return for the Non Blocking case */
if (!(flags & SCIF_SEND_BLOCK))
break;
spin_unlock(&ep->lock);
/* Wait for a SCIF_CLIENT_RCVD message in the Blocking case */
ret =
wait_event_interruptible(ep->sendwq,
(SCIFEP_CONNECTED != ep->state) ||
(scif_rb_space(&qp->outbound_q) >=
curr_xfer_len));
spin_lock(&ep->lock);
if (ret)
break;
}
if (sent_len)
ret = sent_len;
else if (!ret && SCIFEP_CONNECTED != ep->state)
ret = SCIFEP_DISCONNECTED == ep->state ?
-ECONNRESET : -ENOTCONN;
spin_unlock(&ep->lock);
return ret;
}
static int _scif_recv(scif_epd_t epd, void *msg, int len, int flags)
{
int read_size;
struct scif_endpt *ep = (struct scif_endpt *)epd;
struct scifmsg notif_msg;
int curr_recv_len = 0, remaining_len = len, read_count;
int ret = 0;
struct scif_qp *qp = ep->qp_info.qp;
if (flags & SCIF_RECV_BLOCK)
might_sleep();
spin_lock(&ep->lock);
while (remaining_len && (SCIFEP_CONNECTED == ep->state ||
SCIFEP_DISCONNECTED == ep->state)) {
read_count = scif_rb_count(&qp->inbound_q, remaining_len);
if (read_count) {
/*
* Best effort to recv as much data as there
* are bytes to read in the RB particularly
* important for the Non Blocking case.
*/
curr_recv_len = min(remaining_len, read_count);
read_size = scif_rb_get_next(&qp->inbound_q,
msg, curr_recv_len);
if (ep->state == SCIFEP_CONNECTED) {
/*
* Update the read pointer only if the endpoint
* is still connected else the read pointer
* might no longer exist since the peer has
* freed resources!
*/
scif_rb_update_read_ptr(&qp->inbound_q);
/*
* Send a notification to the peer about the
* consumed data message only if the EP is in
* SCIFEP_CONNECTED state.
*/
notif_msg.src = ep->port;
notif_msg.uop = SCIF_CLIENT_RCVD;
notif_msg.payload[0] = ep->remote_ep;
ret = _scif_nodeqp_send(ep->remote_dev,
&notif_msg);
if (ret)
break;
}
remaining_len -= curr_recv_len;
msg = msg + curr_recv_len;
continue;
}
/*
* Bail out now if the EP is in SCIFEP_DISCONNECTED state else
* we will keep looping forever.
*/
if (ep->state == SCIFEP_DISCONNECTED)
break;
/*
* Return in the Non Blocking case if there is no data
* to read in this iteration.
*/
if (!(flags & SCIF_RECV_BLOCK))
break;
curr_recv_len = min(remaining_len, SCIF_ENDPT_QP_SIZE - 1);
spin_unlock(&ep->lock);
/*
* Wait for a SCIF_CLIENT_SEND message in the blocking case
* or until other side disconnects.
*/
ret =
wait_event_interruptible(ep->recvwq,
SCIFEP_CONNECTED != ep->state ||
scif_rb_count(&qp->inbound_q,
curr_recv_len)
>= curr_recv_len);
spin_lock(&ep->lock);
if (ret)
break;
}
if (len - remaining_len)
ret = len - remaining_len;
else if (!ret && ep->state != SCIFEP_CONNECTED)
ret = ep->state == SCIFEP_DISCONNECTED ?
-ECONNRESET : -ENOTCONN;
spin_unlock(&ep->lock);
return ret;
}
/**
* scif_user_send() - Send data to connection queue
* @epd: The end point returned from scif_open()
* @msg: Address to place data
* @len: Length to receive
* @flags: blocking or non blocking
*
* This function is called from the driver IOCTL entry point
* only and is a wrapper for _scif_send().
*/
int scif_user_send(scif_epd_t epd, void __user *msg, int len, int flags)
{
struct scif_endpt *ep = (struct scif_endpt *)epd;
int err = 0;
int sent_len = 0;
char *tmp;
int loop_len;
int chunk_len = min(len, (1 << (MAX_ORDER + PAGE_SHIFT - 1)));
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI send (U): ep %p %s\n", ep, scif_ep_states[ep->state]);
if (!len)
return 0;
err = scif_msg_param_check(epd, len, flags);
if (err)
goto send_err;
tmp = kmalloc(chunk_len, GFP_KERNEL);
if (!tmp) {
err = -ENOMEM;
goto send_err;
}
/*
* Grabbing the lock before breaking up the transfer in
* multiple chunks is required to ensure that messages do
* not get fragmented and reordered.
*/
mutex_lock(&ep->sendlock);
while (sent_len != len) {
loop_len = len - sent_len;
loop_len = min(chunk_len, loop_len);
if (copy_from_user(tmp, msg, loop_len)) {
err = -EFAULT;
goto send_free_err;
}
err = _scif_send(epd, tmp, loop_len, flags);
if (err < 0)
goto send_free_err;
sent_len += err;
msg += err;
if (err != loop_len)
goto send_free_err;
}
send_free_err:
mutex_unlock(&ep->sendlock);
kfree(tmp);
send_err:
return err < 0 ? err : sent_len;
}
/**
* scif_user_recv() - Receive data from connection queue
* @epd: The end point returned from scif_open()
* @msg: Address to place data
* @len: Length to receive
* @flags: blocking or non blocking
*
* This function is called from the driver IOCTL entry point
* only and is a wrapper for _scif_recv().
*/
int scif_user_recv(scif_epd_t epd, void __user *msg, int len, int flags)
{
struct scif_endpt *ep = (struct scif_endpt *)epd;
int err = 0;
int recv_len = 0;
char *tmp;
int loop_len;
int chunk_len = min(len, (1 << (MAX_ORDER + PAGE_SHIFT - 1)));
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI recv (U): ep %p %s\n", ep, scif_ep_states[ep->state]);
if (!len)
return 0;
err = scif_msg_param_check(epd, len, flags);
if (err)
goto recv_err;
tmp = kmalloc(chunk_len, GFP_KERNEL);
if (!tmp) {
err = -ENOMEM;
goto recv_err;
}
/*
* Grabbing the lock before breaking up the transfer in
* multiple chunks is required to ensure that messages do
* not get fragmented and reordered.
*/
mutex_lock(&ep->recvlock);
while (recv_len != len) {
loop_len = len - recv_len;
loop_len = min(chunk_len, loop_len);
err = _scif_recv(epd, tmp, loop_len, flags);
if (err < 0)
goto recv_free_err;
if (copy_to_user(msg, tmp, err)) {
err = -EFAULT;
goto recv_free_err;
}
recv_len += err;
msg += err;
if (err != loop_len)
goto recv_free_err;
}
recv_free_err:
mutex_unlock(&ep->recvlock);
kfree(tmp);
recv_err:
return err < 0 ? err : recv_len;
}
/**
* scif_send() - Send data to connection queue
* @epd: The end point returned from scif_open()
* @msg: Address to place data
* @len: Length to receive
* @flags: blocking or non blocking
*
* This function is called from the kernel mode only and is
* a wrapper for _scif_send().
*/
int scif_send(scif_epd_t epd, void *msg, int len, int flags)
{
struct scif_endpt *ep = (struct scif_endpt *)epd;
int ret;
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI send (K): ep %p %s\n", ep, scif_ep_states[ep->state]);
if (!len)
return 0;
ret = scif_msg_param_check(epd, len, flags);
if (ret)
return ret;
if (!ep->remote_dev)
return -ENOTCONN;
/*
* Grab the mutex lock in the blocking case only
* to ensure messages do not get fragmented/reordered.
* The non blocking mode is protected using spin locks
* in _scif_send().
*/
if (flags & SCIF_SEND_BLOCK)
mutex_lock(&ep->sendlock);
ret = _scif_send(epd, msg, len, flags);
if (flags & SCIF_SEND_BLOCK)
mutex_unlock(&ep->sendlock);
return ret;
}
EXPORT_SYMBOL_GPL(scif_send);
/**
* scif_recv() - Receive data from connection queue
* @epd: The end point returned from scif_open()
* @msg: Address to place data
* @len: Length to receive
* @flags: blocking or non blocking
*
* This function is called from the kernel mode only and is
* a wrapper for _scif_recv().
*/
int scif_recv(scif_epd_t epd, void *msg, int len, int flags)
{
struct scif_endpt *ep = (struct scif_endpt *)epd;
int ret;
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI recv (K): ep %p %s\n", ep, scif_ep_states[ep->state]);
if (!len)
return 0;
ret = scif_msg_param_check(epd, len, flags);
if (ret)
return ret;
/*
* Grab the mutex lock in the blocking case only
* to ensure messages do not get fragmented/reordered.
* The non blocking mode is protected using spin locks
* in _scif_send().
*/
if (flags & SCIF_RECV_BLOCK)
mutex_lock(&ep->recvlock);
ret = _scif_recv(epd, msg, len, flags);
if (flags & SCIF_RECV_BLOCK)
mutex_unlock(&ep->recvlock);
return ret;
}
EXPORT_SYMBOL_GPL(scif_recv);
static inline void _scif_poll_wait(struct file *f, wait_queue_head_t *wq,
poll_table *p, struct scif_endpt *ep)
{
/*
* Because poll_wait makes a GFP_KERNEL allocation, give up the lock
* and regrab it afterwards. Because the endpoint state might have
* changed while the lock was given up, the state must be checked
* again after re-acquiring the lock. The code in __scif_pollfd(..)
* does this.
*/
spin_unlock(&ep->lock);
poll_wait(f, wq, p);
spin_lock(&ep->lock);
}
unsigned int
__scif_pollfd(struct file *f, poll_table *wait, struct scif_endpt *ep)
{
unsigned int mask = 0;
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI pollfd: ep %p %s\n", ep, scif_ep_states[ep->state]);
spin_lock(&ep->lock);
/* Endpoint is waiting for a non-blocking connect to complete */
if (ep->conn_async_state == ASYNC_CONN_INPROGRESS) {
_scif_poll_wait(f, &ep->conn_pend_wq, wait, ep);
if (ep->conn_async_state == ASYNC_CONN_INPROGRESS) {
if (ep->state == SCIFEP_CONNECTED ||
ep->state == SCIFEP_DISCONNECTED ||
ep->conn_err)
mask |= POLLOUT;
goto exit;
}
}
/* Endpoint is listening for incoming connection requests */
if (ep->state == SCIFEP_LISTENING) {
_scif_poll_wait(f, &ep->conwq, wait, ep);
if (ep->state == SCIFEP_LISTENING) {
if (ep->conreqcnt)
mask |= POLLIN;
goto exit;
}
}
/* Endpoint is connected or disconnected */
if (ep->state == SCIFEP_CONNECTED || ep->state == SCIFEP_DISCONNECTED) {
if (poll_requested_events(wait) & POLLIN)
_scif_poll_wait(f, &ep->recvwq, wait, ep);
if (poll_requested_events(wait) & POLLOUT)
_scif_poll_wait(f, &ep->sendwq, wait, ep);
if (ep->state == SCIFEP_CONNECTED ||
ep->state == SCIFEP_DISCONNECTED) {
/* Data can be read without blocking */
if (scif_rb_count(&ep->qp_info.qp->inbound_q, 1))
mask |= POLLIN;
/* Data can be written without blocking */
if (scif_rb_space(&ep->qp_info.qp->outbound_q))
mask |= POLLOUT;
/* Return POLLHUP if endpoint is disconnected */
if (ep->state == SCIFEP_DISCONNECTED)
mask |= POLLHUP;
goto exit;
}
}
/* Return POLLERR if the endpoint is in none of the above states */
mask |= POLLERR;
exit:
spin_unlock(&ep->lock);
return mask;
}
/**
* scif_poll() - Kernel mode SCIF poll
* @ufds: Array of scif_pollepd structures containing the end points
* and events to poll on
* @nfds: Size of the ufds array
* @timeout_msecs: Timeout in msecs, -ve implies infinite timeout
*
* The code flow in this function is based on do_poll(..) in select.c
*
* Returns the number of endpoints which have pending events or 0 in
* the event of a timeout. If a signal is used for wake up, -EINTR is
* returned.
*/
int
scif_poll(struct scif_pollepd *ufds, unsigned int nfds, long timeout_msecs)
{
struct poll_wqueues table;
poll_table *pt;
int i, mask, count = 0, timed_out = timeout_msecs == 0;
u64 timeout = timeout_msecs < 0 ? MAX_SCHEDULE_TIMEOUT
: msecs_to_jiffies(timeout_msecs);
poll_initwait(&table);
pt = &table.pt;
while (1) {
for (i = 0; i < nfds; i++) {
pt->_key = ufds[i].events | POLLERR | POLLHUP;
mask = __scif_pollfd(ufds[i].epd->anon,
pt, ufds[i].epd);
mask &= ufds[i].events | POLLERR | POLLHUP;
if (mask) {
count++;
pt->_qproc = NULL;
}
ufds[i].revents = mask;
}
pt->_qproc = NULL;
if (!count) {
count = table.error;
if (signal_pending(current))
count = -EINTR;
}
if (count || timed_out)
break;
if (!schedule_timeout_interruptible(timeout))
timed_out = 1;
}
poll_freewait(&table);
return count;
}
EXPORT_SYMBOL_GPL(scif_poll);
int scif_get_node_ids(u16 *nodes, int len, u16 *self)
{
int online = 0;
int offset = 0;
int node;
if (!scif_is_mgmt_node())
scif_get_node_info();
*self = scif_info.nodeid;
mutex_lock(&scif_info.conflock);
len = min_t(int, len, scif_info.total);
for (node = 0; node <= scif_info.maxid; node++) {
if (_scifdev_alive(&scif_dev[node])) {
online++;
if (offset < len)
nodes[offset++] = node;
}
}
dev_dbg(scif_info.mdev.this_device,
"SCIFAPI get_node_ids total %d online %d filled in %d nodes\n",
scif_info.total, online, offset);
mutex_unlock(&scif_info.conflock);
return online;
}
EXPORT_SYMBOL_GPL(scif_get_node_ids);
static int scif_add_client_dev(struct device *dev, struct subsys_interface *si)
{
struct scif_client *client =
container_of(si, struct scif_client, si);
struct scif_peer_dev *spdev =
container_of(dev, struct scif_peer_dev, dev);
if (client->probe)
client->probe(spdev);
return 0;
}
static void scif_remove_client_dev(struct device *dev,
struct subsys_interface *si)
{
struct scif_client *client =
container_of(si, struct scif_client, si);
struct scif_peer_dev *spdev =
container_of(dev, struct scif_peer_dev, dev);
if (client->remove)
client->remove(spdev);
}
void scif_client_unregister(struct scif_client *client)
{
subsys_interface_unregister(&client->si);
}
EXPORT_SYMBOL_GPL(scif_client_unregister);
int scif_client_register(struct scif_client *client)
{
struct subsys_interface *si = &client->si;
si->name = client->name;
si->subsys = &scif_peer_bus;
si->add_dev = scif_add_client_dev;
si->remove_dev = scif_remove_client_dev;
return subsys_interface_register(&client->si);
}
EXPORT_SYMBOL_GPL(scif_client_register);
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