diff options
Diffstat (limited to 'drivers/infiniband/core/iwcm.c')
| -rw-r--r-- | drivers/infiniband/core/iwcm.c | 1019 |
1 files changed, 1019 insertions, 0 deletions
diff --git a/drivers/infiniband/core/iwcm.c b/drivers/infiniband/core/iwcm.c new file mode 100644 index 00000000000..c3fb304a4e8 --- /dev/null +++ b/drivers/infiniband/core/iwcm.c @@ -0,0 +1,1019 @@ +/* + * 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/pci.h> +#include <linux/rbtree.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 connectino 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 in the + * cm_id_priv 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 iwcm_id_private *cm_id_priv, + struct iw_cm_event *event) +{ + void *p; + + p = kmalloc(event->private_data_len, GFP_ATOMIC); + if (!p) + return -ENOMEM; + memcpy(p, event->private_data, event->private_data_len); + event->private_data = p; + return 0; +} + +/* + * Release a reference on cm_id. If the last reference is being removed + * and iw_destroy_cm_id is waiting, wake up the waiting thread. + */ +static int iwcm_deref_id(struct iwcm_id_private *cm_id_priv) +{ + int ret = 0; + + 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)); + if (waitqueue_active(&cm_id_priv->destroy_comp.wait)) { + BUG_ON(cm_id_priv->state != IW_CM_STATE_DESTROYING); + BUG_ON(test_bit(IWCM_F_CALLBACK_DESTROY, + &cm_id_priv->flags)); + ret = 1; + } + complete(&cm_id_priv->destroy_comp); + } + + return ret; +} + +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); + iwcm_deref_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 currenlty 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. + */ + cm_id_priv->state = IW_CM_STATE_DESTROYING; + 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); + + dealloc_work_entries(cm_id_priv); + + kfree(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 = 0; + + 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 = 0; + 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); + return; + } + 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)) + return; + + 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); + return; + } + + /* Call the client CM handler */ + ret = cm_id->cm_handler(cm_id, iw_event); + if (ret) { + set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags); + destroy_cm_id(cm_id); + if (atomic_read(&cm_id_priv->refcount)==0) + kfree(cm_id); + } + + 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 = 0; + + 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 = 0; + + 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(void *arg) +{ + struct iwcm_work *work = arg, lwork; + struct iwcm_id_private *cm_id_priv = work->cm_id; + unsigned long flags; + int empty; + int ret = 0; + + 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); + lwork = *work; + put_work(work); + spin_unlock_irqrestore(&cm_id_priv->lock, flags); + + ret = process_event(cm_id_priv, &work->event); + 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); + if (iwcm_deref_id(cm_id_priv)) + return; + + if (atomic_read(&cm_id_priv->refcount)==0 && + test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags)) { + dealloc_work_entries(cm_id_priv); + kfree(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); + 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(cm_id_priv, &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_LOCAL_WRITE | + 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); |