diff options
author | Sudeep Dutt <sudeep.dutt@intel.com> | 2015-04-29 05:32:35 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-05-24 12:13:36 -0700 |
commit | e9089f43c9a79fe97e242de8b5530eceeb5ae8b5 (patch) | |
tree | ddb7809de2ea3774576ad05edd622810f1bd0319 /drivers/misc/mic/scif/scif_api.c | |
parent | 40cb59428c842e6f14be1fe0cb8cfa295080c2e5 (diff) |
misc: mic: SCIF open close bind and listen APIs
SCIF character device file operations and kernel APIs for opening and
closing a user and kernel mode SCIF endpoint. This patch also enables
binding to a SCIF port and listening for incoming SCIF connections.
Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/mic/scif/scif_api.c')
-rw-r--r-- | drivers/misc/mic/scif/scif_api.c | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/drivers/misc/mic/scif/scif_api.c b/drivers/misc/mic/scif/scif_api.c new file mode 100644 index 000000000000..cbdc27b3b187 --- /dev/null +++ b/drivers/misc/mic/scif/scif_api.c @@ -0,0 +1,417 @@ +/* + * 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); |