/*
* Copyright (c) 2004, 2005 Intel Corporation. All rights reserved.
* Copyright (c) 2004 Topspin Corporation. All rights reserved.
* Copyright (c) 2004, 2005 Voltaire Corporation. All rights reserved.
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
* Copyright (c) 2005 Open Grid Computing, Inc. All rights reserved.
* Copyright (c) 2005 Network Appliance, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/rbtree.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/completion.h>
#include <rdma/iw_cm.h>
#include <rdma/ib_addr.h>
#include "iwcm.h"
MODULE_AUTHOR("Tom Tucker");
MODULE_DESCRIPTION("iWARP CM");
MODULE_LICENSE("Dual BSD/GPL");
static struct workqueue_struct *iwcm_wq;
struct iwcm_work {
struct work_struct work;
struct iwcm_id_private *cm_id;
struct list_head list;
struct iw_cm_event event;
struct list_head free_list;
};
/*
* The following services provide a mechanism for pre-allocating iwcm_work
* elements. The design pre-allocates them based on the cm_id type:
* LISTENING IDS: Get enough elements preallocated to handle the
* listen backlog.
* ACTIVE IDS: 4: CONNECT_REPLY, ESTABLISHED, DISCONNECT, CLOSE
* PASSIVE IDS: 3: ESTABLISHED, DISCONNECT, CLOSE
*
* Allocating them in connect and listen avoids having to deal
* with allocation failures on the event upcall from the provider (which
* is called in the interrupt context).
*
* One exception is when creating the cm_id for incoming connection requests.
* There are two cases:
* 1) in the event upcall, cm_event_handler(), for a listening cm_id. If
* the backlog is exceeded, then no more connection request events will
* be processed. cm_event_handler() returns -ENOMEM in this case. Its up
* to the provider to reject the connection request.
* 2) in the connection request workqueue handler, cm_conn_req_handler().
* If work elements cannot be allocated for the new connect request cm_id,
* then IWCM will call the provider reject method. This is ok since
* cm_conn_req_handler() runs in the workqueue thread context.
*/
static struct iwcm_work *get_work(struct iwcm_id_private *cm_id_priv)
{
struct iwcm_work *work;
if (list_empty(&cm_id_priv->work_free_list))
return NULL;
work = list_entry(cm_id_priv->work_free_list.next, struct iwcm_work,
free_list);
list_del_init(&work->free_list);
return work;
}
static void put_work(struct iwcm_work *work)
{
list_add(&work->free_list, &work->cm_id->work_free_list);
}
static void dealloc_work_entries(struct iwcm_id_private *cm_id_priv)
{
struct list_head *e, *tmp;
list_for_each_safe(e, tmp, &cm_id_priv->work_free_list)
kfree(list_entry(e, struct iwcm_work, free_list));
}
static int alloc_work_entries(struct iwcm_id_private *cm_id_priv, int count)
{
struct iwcm_work *work;
BUG_ON(!list_empty(&cm_id_priv->work_free_list));
while (count--) {
work = kmalloc(sizeof(struct iwcm_work), GFP_KERNEL);
if (!work) {
dealloc_work_entries(cm_id_priv);
return -ENOMEM;
}
work->cm_id = cm_id_priv;
INIT_LIST_HEAD(&work->list);
put_work(work);
}
return 0;
}
/*
* Save private data from incoming connection requests to
* iw_cm_event, so the low level driver doesn't have to. Adjust
* the event ptr to point to the local copy.
*/
static int copy_private_data(struct iw_cm_event *event)
{
void *p;
p = kmemdup(event->private_data, event->private_data_len, GFP_ATOMIC);
if (!p)
return -ENOMEM;
event->private_data = p;
return 0;
}
static void free_cm_id(struct iwcm_id_private *cm_id_priv)
{
dealloc_work_entries(cm_id_priv);
kfree(cm_id_priv);
}
/*
* Release a reference on cm_id. If the last reference is being
* released, enable the waiting thread (in iw_destroy_cm_id) to
* get woken up, and return 1 if a thread is already waiting.
*/
static int iwcm_deref_id(struct iwcm_id_private *cm_id_priv)
{
BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
if (atomic_dec_and_test(&cm_id_priv->refcount)) {
BUG_ON(!list_empty(&cm_id_priv->work_list));
complete(&cm_id_priv->destroy_comp);
return 1;
}
return 0;
}
static void add_ref(struct iw_cm_id *cm_id)
{
struct iwcm_id_private *cm_id_priv;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
atomic_inc(&cm_id_priv->refcount);
}
static void rem_ref(struct iw_cm_id *cm_id)
{
struct iwcm_id_private *cm_id_priv;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
if (iwcm_deref_id(cm_id_priv) &&
test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags)) {
BUG_ON(!list_empty(&cm_id_priv->work_list));
free_cm_id(cm_id_priv);
}
}
static int cm_event_handler(struct iw_cm_id *cm_id, struct iw_cm_event *event);
struct iw_cm_id *iw_create_cm_id(struct ib_device *device,
iw_cm_handler cm_handler,
void *context)
{
struct iwcm_id_private *cm_id_priv;
cm_id_priv = kzalloc(sizeof(*cm_id_priv), GFP_KERNEL);
if (!cm_id_priv)
return ERR_PTR(-ENOMEM);
cm_id_priv->state = IW_CM_STATE_IDLE;
cm_id_priv->id.device = device;
cm_id_priv->id.cm_handler = cm_handler;
cm_id_priv->id.context = context;
cm_id_priv->id.event_handler = cm_event_handler;
cm_id_priv->id.add_ref = add_ref;
cm_id_priv->id.rem_ref = rem_ref;
spin_lock_init(&cm_id_priv->lock);
atomic_set(&cm_id_priv->refcount, 1);
init_waitqueue_head(&cm_id_priv->connect_wait);
init_completion(&cm_id_priv->destroy_comp);
INIT_LIST_HEAD(&cm_id_priv->work_list);
INIT_LIST_HEAD(&cm_id_priv->work_free_list);
return &cm_id_priv->id;
}
EXPORT_SYMBOL(iw_create_cm_id);
static int iwcm_modify_qp_err(struct ib_qp *qp)
{
struct ib_qp_attr qp_attr;
if (!qp)
return -EINVAL;
qp_attr.qp_state = IB_QPS_ERR;
return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
}
/*
* This is really the RDMAC CLOSING state. It is most similar to the
* IB SQD QP state.
*/
static int iwcm_modify_qp_sqd(struct ib_qp *qp)
{
struct ib_qp_attr qp_attr;
BUG_ON(qp == NULL);
qp_attr.qp_state = IB_QPS_SQD;
return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
}
/*
* CM_ID <-- CLOSING
*
* Block if a passive or active connection is currently being processed. Then
* process the event as follows:
* - If we are ESTABLISHED, move to CLOSING and modify the QP state
* based on the abrupt flag
* - If the connection is already in the CLOSING or IDLE state, the peer is
* disconnecting concurrently with us and we've already seen the
* DISCONNECT event -- ignore the request and return 0
* - Disconnect on a listening endpoint returns -EINVAL
*/
int iw_cm_disconnect(struct iw_cm_id *cm_id, int abrupt)
{
struct iwcm_id_private *cm_id_priv;
unsigned long flags;
int ret = 0;
struct ib_qp *qp = NULL;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
/* Wait if we're currently in a connect or accept downcall */
wait_event(cm_id_priv->connect_wait,
!test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
spin_lock_irqsave(&cm_id_priv->lock, flags);
switch (cm_id_priv->state) {
case IW_CM_STATE_ESTABLISHED:
cm_id_priv->state = IW_CM_STATE_CLOSING;
/* QP could be <nul> for user-mode client */
if (cm_id_priv->qp)
qp = cm_id_priv->qp;
else
ret = -EINVAL;
break;
case IW_CM_STATE_LISTEN:
ret = -EINVAL;
break;
case IW_CM_STATE_CLOSING:
/* remote peer closed first */
case IW_CM_STATE_IDLE:
/* accept or connect returned !0 */
break;
case IW_CM_STATE_CONN_RECV:
/*
* App called disconnect before/without calling accept after
* connect_request event delivered.
*/
break;
case IW_CM_STATE_CONN_SENT:
/* Can only get here if wait above fails */
default:
BUG();
}
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
if (qp) {
if (abrupt)
ret = iwcm_modify_qp_err(qp);
else
ret = iwcm_modify_qp_sqd(qp);
/*
* If both sides are disconnecting the QP could
* already be in ERR or SQD states
*/
ret = 0;
}
return ret;
}
EXPORT_SYMBOL(iw_cm_disconnect);
/*
* CM_ID <-- DESTROYING
*
* Clean up all resources associated with the connection and release
* the initial reference taken by iw_create_cm_id.
*/
static void destroy_cm_id(struct iw_cm_id *cm_id)
{
struct iwcm_id_private *cm_id_priv;
unsigned long flags;
int ret;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
/*
* Wait if we're currently in a connect or accept downcall. A
* listening endpoint should never block here.
*/
wait_event(cm_id_priv->connect_wait,
!test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
spin_lock_irqsave(&cm_id_priv->lock, flags);
switch (cm_id_priv->state) {
case IW_CM_STATE_LISTEN:
cm_id_priv->state = IW_CM_STATE_DESTROYING;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
/* destroy the listening endpoint */
ret = cm_id->device->iwcm->destroy_listen(cm_id);
spin_lock_irqsave(&cm_id_priv->lock, flags);
break;
case IW_CM_STATE_ESTABLISHED:
cm_id_priv->state = IW_CM_STATE_DESTROYING;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
/* Abrupt close of the connection */
(void)iwcm_modify_qp_err(cm_id_priv->qp);
spin_lock_irqsave(&cm_id_priv->lock, flags);
break;
case IW_CM_STATE_IDLE:
case IW_CM_STATE_CLOSING:
cm_id_priv->state = IW_CM_STATE_DESTROYING;
break;
case IW_CM_STATE_CONN_RECV:
/*
* App called destroy before/without calling accept after
* receiving connection request event notification or
* returned non zero from the event callback function.
* In either case, must tell the provider to reject.
*/
cm_id_priv->state = IW_CM_STATE_DESTROYING;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
cm_id->device->iwcm->reject(cm_id, NULL, 0);
spin_lock_irqsave(&cm_id_priv->lock, flags);
break;
case IW_CM_STATE_CONN_SENT:
case IW_CM_STATE_DESTROYING:
default:
BUG();
break;
}
if (cm_id_priv->qp) {
cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
cm_id_priv->qp = NULL;
}
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
(void)iwcm_deref_id(cm_id_priv);
}
/*
* This function is only called by the application thread and cannot
* be called by the event thread. The function will wait for all
* references to be released on the cm_id and then kfree the cm_id
* object.
*/
void iw_destroy_cm_id(struct iw_cm_id *cm_id)
{
struct iwcm_id_private *cm_id_priv;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
BUG_ON(test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags));
destroy_cm_id(cm_id);
wait_for_completion(&cm_id_priv->destroy_comp);
free_cm_id(cm_id_priv);
}
EXPORT_SYMBOL(iw_destroy_cm_id);
/*
* CM_ID <-- LISTEN
*
* Start listening for connect requests. Generates one CONNECT_REQUEST
* event for each inbound connect request.
*/
int iw_cm_listen(struct iw_cm_id *cm_id, int backlog)
{
struct iwcm_id_private *cm_id_priv;
unsigned long flags;
int ret;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
ret = alloc_work_entries(cm_id_priv, backlog);
if (ret)
return ret;
spin_lock_irqsave(&cm_id_priv->lock, flags);
switch (cm_id_priv->state) {
case IW_CM_STATE_IDLE:
cm_id_priv->state = IW_CM_STATE_LISTEN;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
ret = cm_id->device->iwcm->create_listen(cm_id, backlog);
if (ret)
cm_id_priv->state = IW_CM_STATE_IDLE;
spin_lock_irqsave(&cm_id_priv->lock, flags);
break;
default:
ret = -EINVAL;
}
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
return ret;
}
EXPORT_SYMBOL(iw_cm_listen);
/*
* CM_ID <-- IDLE
*
* Rejects an inbound connection request. No events are generated.
*/
int iw_cm_reject(struct iw_cm_id *cm_id,
const void *private_data,
u8 private_data_len)
{
struct iwcm_id_private *cm_id_priv;
unsigned long flags;
int ret;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
spin_lock_irqsave(&cm_id_priv->lock, flags);
if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
wake_up_all(&cm_id_priv->connect_wait);
return -EINVAL;
}
cm_id_priv->state = IW_CM_STATE_IDLE;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
ret = cm_id->device->iwcm->reject(cm_id, private_data,
private_data_len);
clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
wake_up_all(&cm_id_priv->connect_wait);
return ret;
}
EXPORT_SYMBOL(iw_cm_reject);
/*
* CM_ID <-- ESTABLISHED
*
* Accepts an inbound connection request and generates an ESTABLISHED
* event. Callers of iw_cm_disconnect and iw_destroy_cm_id will block
* until the ESTABLISHED event is received from the provider.
*/
int iw_cm_accept(struct iw_cm_id *cm_id,
struct iw_cm_conn_param *iw_param)
{
struct iwcm_id_private *cm_id_priv;
struct ib_qp *qp;
unsigned long flags;
int ret;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
spin_lock_irqsave(&cm_id_priv->lock, flags);
if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
wake_up_all(&cm_id_priv->connect_wait);
return -EINVAL;
}
/* Get the ib_qp given the QPN */
qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
if (!qp) {
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
return -EINVAL;
}
cm_id->device->iwcm->add_ref(qp);
cm_id_priv->qp = qp;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
ret = cm_id->device->iwcm->accept(cm_id, iw_param);
if (ret) {
/* An error on accept precludes provider events */
BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
cm_id_priv->state = IW_CM_STATE_IDLE;
spin_lock_irqsave(&cm_id_priv->lock, flags);
if (cm_id_priv->qp) {
cm_id->device->iwcm->rem_ref(qp);
cm_id_priv->qp = NULL;
}
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
wake_up_all(&cm_id_priv->connect_wait);
}
return ret;
}
EXPORT_SYMBOL(iw_cm_accept);
/*
* Active Side: CM_ID <-- CONN_SENT
*
* If successful, results in the generation of a CONNECT_REPLY
* event. iw_cm_disconnect and iw_cm_destroy will block until the
* CONNECT_REPLY event is received from the provider.
*/
int iw_cm_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *iw_param)
{
struct iwcm_id_private *cm_id_priv;
int ret;
unsigned long flags;
struct ib_qp *qp;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
ret = alloc_work_entries(cm_id_priv, 4);
if (ret)
return ret;
set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
spin_lock_irqsave(&cm_id_priv->lock, flags);
if (cm_id_priv->state != IW_CM_STATE_IDLE) {
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
wake_up_all(&cm_id_priv->connect_wait);
return -EINVAL;
}
/* Get the ib_qp given the QPN */
qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
if (!qp) {
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
return -EINVAL;
}
cm_id->device->iwcm->add_ref(qp);
cm_id_priv->qp = qp;
cm_id_priv->state = IW_CM_STATE_CONN_SENT;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
ret = cm_id->device->iwcm->connect(cm_id, iw_param);
if (ret) {
spin_lock_irqsave(&cm_id_priv->lock, flags);
if (cm_id_priv->qp) {
cm_id->device->iwcm->rem_ref(qp);
cm_id_priv->qp = NULL;
}
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
cm_id_priv->state = IW_CM_STATE_IDLE;
clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
wake_up_all(&cm_id_priv->connect_wait);
}
return ret;
}
EXPORT_SYMBOL(iw_cm_connect);
/*
* Passive Side: new CM_ID <-- CONN_RECV
*
* Handles an inbound connect request. The function creates a new
* iw_cm_id to represent the new connection and inherits the client
* callback function and other attributes from the listening parent.
*
* The work item contains a pointer to the listen_cm_id and the event. The
* listen_cm_id contains the client cm_handler, context and
* device. These are copied when the device is cloned. The event
* contains the new four tuple.
*
* An error on the child should not affect the parent, so this
* function does not return a value.
*/
static void cm_conn_req_handler(struct iwcm_id_private *listen_id_priv,
struct iw_cm_event *iw_event)
{
unsigned long flags;
struct iw_cm_id *cm_id;
struct iwcm_id_private *cm_id_priv;
int ret;
/*
* The provider should never generate a connection request
* event with a bad status.
*/
BUG_ON(iw_event->status);
/*
* We could be destroying the listening id. If so, ignore this
* upcall.
*/
spin_lock_irqsave(&listen_id_priv->lock, flags);
if (listen_id_priv->state != IW_CM_STATE_LISTEN) {
spin_unlock_irqrestore(&listen_id_priv->lock, flags);
goto out;
}
spin_unlock_irqrestore(&listen_id_priv->lock, flags);
cm_id = iw_create_cm_id(listen_id_priv->id.device,
listen_id_priv->id.cm_handler,
listen_id_priv->id.context);
/* If the cm_id could not be created, ignore the request */
if (IS_ERR(cm_id))
goto out;
cm_id->provider_data = iw_event->provider_data;
cm_id->local_addr = iw_event->local_addr;
cm_id->remote_addr = iw_event->remote_addr;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
cm_id_priv->state = IW_CM_STATE_CONN_RECV;
ret = alloc_work_entries(cm_id_priv, 3);
if (ret) {
iw_cm_reject(cm_id, NULL, 0);
iw_destroy_cm_id(cm_id);
goto out;
}
/* Call the client CM handler */
ret = cm_id->cm_handler(cm_id, iw_event);
if (ret) {
iw_cm_reject(cm_id, NULL, 0);
set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
destroy_cm_id(cm_id);
if (atomic_read(&cm_id_priv->refcount)==0)
free_cm_id(cm_id_priv);
}
out:
if (iw_event->private_data_len)
kfree(iw_event->private_data);
}
/*
* Passive Side: CM_ID <-- ESTABLISHED
*
* The provider generated an ESTABLISHED event which means that
* the MPA negotion has completed successfully and we are now in MPA
* FPDU mode.
*
* This event can only be received in the CONN_RECV state. If the
* remote peer closed, the ESTABLISHED event would be received followed
* by the CLOSE event. If the app closes, it will block until we wake
* it up after processing this event.
*/
static int cm_conn_est_handler(struct iwcm_id_private *cm_id_priv,
struct iw_cm_event *iw_event)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&cm_id_priv->lock, flags);
/*
* We clear the CONNECT_WAIT bit here to allow the callback
* function to call iw_cm_disconnect. Calling iw_destroy_cm_id
* from a callback handler is not allowed.
*/
clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
wake_up_all(&cm_id_priv->connect_wait);
return ret;
}
/*
* Active Side: CM_ID <-- ESTABLISHED
*
* The app has called connect and is waiting for the established event to
* post it's requests to the server. This event will wake up anyone
* blocked in iw_cm_disconnect or iw_destroy_id.
*/
static int cm_conn_rep_handler(struct iwcm_id_private *cm_id_priv,
struct iw_cm_event *iw_event)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&cm_id_priv->lock, flags);
/*
* Clear the connect wait bit so a callback function calling
* iw_cm_disconnect will not wait and deadlock this thread
*/
clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
if (iw_event->status == IW_CM_EVENT_STATUS_ACCEPTED) {
cm_id_priv->id.local_addr = iw_event->local_addr;
cm_id_priv->id.remote_addr = iw_event->remote_addr;
cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
} else {
/* REJECTED or RESET */
cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
cm_id_priv->qp = NULL;
cm_id_priv->state = IW_CM_STATE_IDLE;
}
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
if (iw_event->private_data_len)
kfree(iw_event->private_data);
/* Wake up waiters on connect complete */
wake_up_all(&cm_id_priv->connect_wait);
return ret;
}
/*
* CM_ID <-- CLOSING
*
* If in the ESTABLISHED state, move to CLOSING.
*/
static void cm_disconnect_handler(struct iwcm_id_private *cm_id_priv,
struct iw_cm_event *iw_event)
{
unsigned long flags;
spin_lock_irqsave(&cm_id_priv->lock, flags);
if (cm_id_priv->state == IW_CM_STATE_ESTABLISHED)
cm_id_priv->state = IW_CM_STATE_CLOSING;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
}
/*
* CM_ID <-- IDLE
*
* If in the ESTBLISHED or CLOSING states, the QP will have have been
* moved by the provider to the ERR state. Disassociate the CM_ID from
* the QP, move to IDLE, and remove the 'connected' reference.
*
* If in some other state, the cm_id was destroyed asynchronously.
* This is the last reference that will result in waking up
* the app thread blocked in iw_destroy_cm_id.
*/
static int cm_close_handler(struct iwcm_id_private *cm_id_priv,
struct iw_cm_event *iw_event)
{
unsigned long flags;
int ret = 0;
spin_lock_irqsave(&cm_id_priv->lock, flags);
if (cm_id_priv->qp) {
cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
cm_id_priv->qp = NULL;
}
switch (cm_id_priv->state) {
case IW_CM_STATE_ESTABLISHED:
case IW_CM_STATE_CLOSING:
cm_id_priv->state = IW_CM_STATE_IDLE;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
spin_lock_irqsave(&cm_id_priv->lock, flags);
break;
case IW_CM_STATE_DESTROYING:
break;
default:
BUG();
}
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
return ret;
}
static int process_event(struct iwcm_id_private *cm_id_priv,
struct iw_cm_event *iw_event)
{
int ret = 0;
switch (iw_event->event) {
case IW_CM_EVENT_CONNECT_REQUEST:
cm_conn_req_handler(cm_id_priv, iw_event);
break;
case IW_CM_EVENT_CONNECT_REPLY:
ret = cm_conn_rep_handler(cm_id_priv, iw_event);
break;
case IW_CM_EVENT_ESTABLISHED:
ret = cm_conn_est_handler(cm_id_priv, iw_event);
break;
case IW_CM_EVENT_DISCONNECT:
cm_disconnect_handler(cm_id_priv, iw_event);
break;
case IW_CM_EVENT_CLOSE:
ret = cm_close_handler(cm_id_priv, iw_event);
break;
default:
BUG();
}
return ret;
}
/*
* Process events on the work_list for the cm_id. If the callback
* function requests that the cm_id be deleted, a flag is set in the
* cm_id flags to indicate that when the last reference is
* removed, the cm_id is to be destroyed. This is necessary to
* distinguish between an object that will be destroyed by the app
* thread asleep on the destroy_comp list vs. an object destroyed
* here synchronously when the last reference is removed.
*/
static void cm_work_handler(struct work_struct *_work)
{
struct iwcm_work *work = container_of(_work, struct iwcm_work, work);
struct iw_cm_event levent;
struct iwcm_id_private *cm_id_priv = work->cm_id;
unsigned long flags;
int empty;
int ret = 0;
int destroy_id;
spin_lock_irqsave(&cm_id_priv->lock, flags);
empty = list_empty(&cm_id_priv->work_list);
while (!empty) {
work = list_entry(cm_id_priv->work_list.next,
struct iwcm_work, list);
list_del_init(&work->list);
empty = list_empty(&cm_id_priv->work_list);
levent = work->event;
put_work(work);
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
ret = process_event(cm_id_priv, &levent);
if (ret) {
set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
destroy_cm_id(&cm_id_priv->id);
}
BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
destroy_id = test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
if (iwcm_deref_id(cm_id_priv)) {
if (destroy_id) {
BUG_ON(!list_empty(&cm_id_priv->work_list));
free_cm_id(cm_id_priv);
}
return;
}
spin_lock_irqsave(&cm_id_priv->lock, flags);
}
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
}
/*
* This function is called on interrupt context. Schedule events on
* the iwcm_wq thread to allow callback functions to downcall into
* the CM and/or block. Events are queued to a per-CM_ID
* work_list. If this is the first event on the work_list, the work
* element is also queued on the iwcm_wq thread.
*
* Each event holds a reference on the cm_id. Until the last posted
* event has been delivered and processed, the cm_id cannot be
* deleted.
*
* Returns:
* 0 - the event was handled.
* -ENOMEM - the event was not handled due to lack of resources.
*/
static int cm_event_handler(struct iw_cm_id *cm_id,
struct iw_cm_event *iw_event)
{
struct iwcm_work *work;
struct iwcm_id_private *cm_id_priv;
unsigned long flags;
int ret = 0;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
spin_lock_irqsave(&cm_id_priv->lock, flags);
work = get_work(cm_id_priv);
if (!work) {
ret = -ENOMEM;
goto out;
}
INIT_WORK(&work->work, cm_work_handler);
work->cm_id = cm_id_priv;
work->event = *iw_event;
if ((work->event.event == IW_CM_EVENT_CONNECT_REQUEST ||
work->event.event == IW_CM_EVENT_CONNECT_REPLY) &&
work->event.private_data_len) {
ret = copy_private_data(&work->event);
if (ret) {
put_work(work);
goto out;
}
}
atomic_inc(&cm_id_priv->refcount);
if (list_empty(&cm_id_priv->work_list)) {
list_add_tail(&work->list, &cm_id_priv->work_list);
queue_work(iwcm_wq, &work->work);
} else
list_add_tail(&work->list, &cm_id_priv->work_list);
out:
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
return ret;
}
static int iwcm_init_qp_init_attr(struct iwcm_id_private *cm_id_priv,
struct ib_qp_attr *qp_attr,
int *qp_attr_mask)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&cm_id_priv->lock, flags);
switch (cm_id_priv->state) {
case IW_CM_STATE_IDLE:
case IW_CM_STATE_CONN_SENT:
case IW_CM_STATE_CONN_RECV:
case IW_CM_STATE_ESTABLISHED:
*qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS;
qp_attr->qp_access_flags = IB_ACCESS_REMOTE_WRITE|
IB_ACCESS_REMOTE_READ;
ret = 0;
break;
default:
ret = -EINVAL;
break;
}
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
return ret;
}
static int iwcm_init_qp_rts_attr(struct iwcm_id_private *cm_id_priv,
struct ib_qp_attr *qp_attr,
int *qp_attr_mask)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&cm_id_priv->lock, flags);
switch (cm_id_priv->state) {
case IW_CM_STATE_IDLE:
case IW_CM_STATE_CONN_SENT:
case IW_CM_STATE_CONN_RECV:
case IW_CM_STATE_ESTABLISHED:
*qp_attr_mask = 0;
ret = 0;
break;
default:
ret = -EINVAL;
break;
}
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
return ret;
}
int iw_cm_init_qp_attr(struct iw_cm_id *cm_id,
struct ib_qp_attr *qp_attr,
int *qp_attr_mask)
{
struct iwcm_id_private *cm_id_priv;
int ret;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
switch (qp_attr->qp_state) {
case IB_QPS_INIT:
case IB_QPS_RTR:
ret = iwcm_init_qp_init_attr(cm_id_priv,
qp_attr, qp_attr_mask);
break;
case IB_QPS_RTS:
ret = iwcm_init_qp_rts_attr(cm_id_priv,
qp_attr, qp_attr_mask);
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
EXPORT_SYMBOL(iw_cm_init_qp_attr);
static int __init iw_cm_init(void)
{
iwcm_wq = create_singlethread_workqueue("iw_cm_wq");
if (!iwcm_wq)
return -ENOMEM;
return 0;
}
static void __exit iw_cm_cleanup(void)
{
destroy_workqueue(iwcm_wq);
}
module_init(iw_cm_init);
module_exit(iw_cm_cleanup);
