module_param(rds_ib_retry_count, int, 0444);
MODULE_PARM_DESC(rds_ib_retry_count, " Number of hw retries before reporting an error");
+/*
+ * we have a clumsy combination of RCU and a rwsem protecting this list
+ * because it is used both in the get_mr fast path and while blocking in
+ * the FMR flushing path.
+ */
+DECLARE_RWSEM(rds_ib_devices_lock);
struct list_head rds_ib_devices;
/* NOTE: if also grabbing ibdev lock, grab this first */
DEFINE_SPINLOCK(ib_nodev_conns_lock);
LIST_HEAD(ib_nodev_conns);
+void rds_ib_nodev_connect(void)
+{
+ struct rds_ib_connection *ic;
+
+ spin_lock(&ib_nodev_conns_lock);
+ list_for_each_entry(ic, &ib_nodev_conns, ib_node)
+ rds_conn_connect_if_down(ic->conn);
+ spin_unlock(&ib_nodev_conns_lock);
+}
+
+void rds_ib_dev_shutdown(struct rds_ib_device *rds_ibdev)
+{
+ struct rds_ib_connection *ic;
+ unsigned long flags;
+
+ spin_lock_irqsave(&rds_ibdev->spinlock, flags);
+ list_for_each_entry(ic, &rds_ibdev->conn_list, ib_node)
+ rds_conn_drop(ic->conn);
+ spin_unlock_irqrestore(&rds_ibdev->spinlock, flags);
+}
+
+/*
+ * rds_ib_destroy_mr_pool() blocks on a few things and mrs drop references
+ * from interrupt context so we push freing off into a work struct in krdsd.
+ */
+static void rds_ib_dev_free(struct work_struct *work)
+{
+ struct rds_ib_ipaddr *i_ipaddr, *i_next;
+ struct rds_ib_device *rds_ibdev = container_of(work,
+ struct rds_ib_device, free_work);
+
+ if (rds_ibdev->mr_pool)
+ rds_ib_destroy_mr_pool(rds_ibdev->mr_pool);
+ if (rds_ibdev->mr)
+ ib_dereg_mr(rds_ibdev->mr);
+ if (rds_ibdev->pd)
+ ib_dealloc_pd(rds_ibdev->pd);
+
+ list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) {
+ list_del(&i_ipaddr->list);
+ kfree(i_ipaddr);
+ }
+
+ kfree(rds_ibdev);
+}
+
+void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
+{
+ BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0);
+ if (atomic_dec_and_test(&rds_ibdev->refcount))
+ queue_work(rds_wq, &rds_ibdev->free_work);
+}
+
void rds_ib_add_one(struct ib_device *device)
{
struct rds_ib_device *rds_ibdev;
goto free_attr;
}
- rds_ibdev = kmalloc(sizeof *rds_ibdev, GFP_KERNEL);
+ rds_ibdev = kzalloc_node(sizeof(struct rds_ib_device), GFP_KERNEL,
+ ibdev_to_node(device));
if (!rds_ibdev)
goto free_attr;
spin_lock_init(&rds_ibdev->spinlock);
+ atomic_set(&rds_ibdev->refcount, 1);
+ INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
rds_ibdev->max_wrs = dev_attr->max_qp_wr;
rds_ibdev->max_sge = min(dev_attr->max_sge, RDS_IB_MAX_SGE);
min_t(unsigned int, dev_attr->max_fmr, fmr_pool_size) :
fmr_pool_size;
+ rds_ibdev->max_initiator_depth = dev_attr->max_qp_init_rd_atom;
+ rds_ibdev->max_responder_resources = dev_attr->max_qp_rd_atom;
+
rds_ibdev->dev = device;
rds_ibdev->pd = ib_alloc_pd(device);
- if (IS_ERR(rds_ibdev->pd))
- goto free_dev;
+ if (IS_ERR(rds_ibdev->pd)) {
+ rds_ibdev->pd = NULL;
+ goto put_dev;
+ }
- rds_ibdev->mr = ib_get_dma_mr(rds_ibdev->pd,
- IB_ACCESS_LOCAL_WRITE);
- if (IS_ERR(rds_ibdev->mr))
- goto err_pd;
+ rds_ibdev->mr = ib_get_dma_mr(rds_ibdev->pd, IB_ACCESS_LOCAL_WRITE);
+ if (IS_ERR(rds_ibdev->mr)) {
+ rds_ibdev->mr = NULL;
+ goto put_dev;
+ }
rds_ibdev->mr_pool = rds_ib_create_mr_pool(rds_ibdev);
if (IS_ERR(rds_ibdev->mr_pool)) {
rds_ibdev->mr_pool = NULL;
- goto err_mr;
+ goto put_dev;
}
INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
INIT_LIST_HEAD(&rds_ibdev->conn_list);
- list_add_tail(&rds_ibdev->list, &rds_ib_devices);
+
+ down_write(&rds_ib_devices_lock);
+ list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
+ up_write(&rds_ib_devices_lock);
+ atomic_inc(&rds_ibdev->refcount);
ib_set_client_data(device, &rds_ib_client, rds_ibdev);
+ atomic_inc(&rds_ibdev->refcount);
- goto free_attr;
+ rds_ib_nodev_connect();
-err_mr:
- ib_dereg_mr(rds_ibdev->mr);
-err_pd:
- ib_dealloc_pd(rds_ibdev->pd);
-free_dev:
- kfree(rds_ibdev);
+put_dev:
+ rds_ib_dev_put(rds_ibdev);
free_attr:
kfree(dev_attr);
}
+/*
+ * New connections use this to find the device to associate with the
+ * connection. It's not in the fast path so we're not concerned about the
+ * performance of the IB call. (As of this writing, it uses an interrupt
+ * blocking spinlock to serialize walking a per-device list of all registered
+ * clients.)
+ *
+ * RCU is used to handle incoming connections racing with device teardown.
+ * Rather than use a lock to serialize removal from the client_data and
+ * getting a new reference, we use an RCU grace period. The destruction
+ * path removes the device from client_data and then waits for all RCU
+ * readers to finish.
+ *
+ * A new connection can get NULL from this if its arriving on a
+ * device that is in the process of being removed.
+ */
+struct rds_ib_device *rds_ib_get_client_data(struct ib_device *device)
+{
+ struct rds_ib_device *rds_ibdev;
+
+ rcu_read_lock();
+ rds_ibdev = ib_get_client_data(device, &rds_ib_client);
+ if (rds_ibdev)
+ atomic_inc(&rds_ibdev->refcount);
+ rcu_read_unlock();
+ return rds_ibdev;
+}
+
+/*
+ * The IB stack is letting us know that a device is going away. This can
+ * happen if the underlying HCA driver is removed or if PCI hotplug is removing
+ * the pci function, for example.
+ *
+ * This can be called at any time and can be racing with any other RDS path.
+ */
void rds_ib_remove_one(struct ib_device *device)
{
struct rds_ib_device *rds_ibdev;
- struct rds_ib_ipaddr *i_ipaddr, *i_next;
rds_ibdev = ib_get_client_data(device, &rds_ib_client);
if (!rds_ibdev)
return;
- list_for_each_entry_safe(i_ipaddr, i_next, &rds_ibdev->ipaddr_list, list) {
- list_del(&i_ipaddr->list);
- kfree(i_ipaddr);
- }
+ rds_ib_dev_shutdown(rds_ibdev);
- rds_ib_destroy_conns(rds_ibdev);
+ /* stop connection attempts from getting a reference to this device. */
+ ib_set_client_data(device, &rds_ib_client, NULL);
- if (rds_ibdev->mr_pool)
- rds_ib_destroy_mr_pool(rds_ibdev->mr_pool);
-
- ib_dereg_mr(rds_ibdev->mr);
-
- while (ib_dealloc_pd(rds_ibdev->pd)) {
- rdsdebug("Failed to dealloc pd %p\n", rds_ibdev->pd);
- msleep(1);
- }
+ down_write(&rds_ib_devices_lock);
+ list_del_rcu(&rds_ibdev->list);
+ up_write(&rds_ib_devices_lock);
- list_del(&rds_ibdev->list);
- kfree(rds_ibdev);
+ /*
+ * This synchronize rcu is waiting for readers of both the ib
+ * client data and the devices list to finish before we drop
+ * both of those references.
+ */
+ synchronize_rcu();
+ rds_ib_dev_put(rds_ibdev);
+ rds_ib_dev_put(rds_ibdev);
}
struct ib_client rds_ib_client = {
rdma_addr_get_sgid(dev_addr, (union ib_gid *) &iinfo->src_gid);
rdma_addr_get_dgid(dev_addr, (union ib_gid *) &iinfo->dst_gid);
- rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client);
+ rds_ibdev = ic->rds_ibdev;
iinfo->max_send_wr = ic->i_send_ring.w_nr;
iinfo->max_recv_wr = ic->i_recv_ring.w_nr;
iinfo->max_send_sge = rds_ibdev->max_sge;
return ret;
}
+static void rds_ib_unregister_client(void)
+{
+ ib_unregister_client(&rds_ib_client);
+ /* wait for rds_ib_dev_free() to complete */
+ flush_workqueue(rds_wq);
+}
+
void rds_ib_exit(void)
{
rds_info_deregister_func(RDS_INFO_IB_CONNECTIONS, rds_ib_ic_info);
+ rds_ib_unregister_client();
rds_ib_destroy_nodev_conns();
- ib_unregister_client(&rds_ib_client);
rds_ib_sysctl_exit();
rds_ib_recv_exit();
rds_trans_unregister(&rds_ib_transport);
+ rds_ib_fmr_exit();
}
struct rds_transport rds_ib_transport = {
.laddr_check = rds_ib_laddr_check,
.xmit_complete = rds_ib_xmit_complete,
.xmit = rds_ib_xmit,
- .xmit_cong_map = NULL,
.xmit_rdma = rds_ib_xmit_rdma,
+ .xmit_atomic = rds_ib_xmit_atomic,
.recv = rds_ib_recv,
.conn_alloc = rds_ib_conn_alloc,
.conn_free = rds_ib_conn_free,
.conn_connect = rds_ib_conn_connect,
.conn_shutdown = rds_ib_conn_shutdown,
.inc_copy_to_user = rds_ib_inc_copy_to_user,
- .inc_purge = rds_ib_inc_purge,
.inc_free = rds_ib_inc_free,
.cm_initiate_connect = rds_ib_cm_initiate_connect,
.cm_handle_connect = rds_ib_cm_handle_connect,
.t_type = RDS_TRANS_IB
};
-int __init rds_ib_init(void)
+int rds_ib_init(void)
{
int ret;
INIT_LIST_HEAD(&rds_ib_devices);
- ret = ib_register_client(&rds_ib_client);
+ ret = rds_ib_fmr_init();
if (ret)
goto out;
+ ret = ib_register_client(&rds_ib_client);
+ if (ret)
+ goto out_fmr_exit;
+
ret = rds_ib_sysctl_init();
if (ret)
goto out_ibreg;
out_sysctl:
rds_ib_sysctl_exit();
out_ibreg:
- ib_unregister_client(&rds_ib_client);
+ rds_ib_unregister_client();
+out_fmr_exit:
+ rds_ib_fmr_exit();
out:
return ret;
}
projects / mv-sheeva.git / blobdiff