X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=net%2Frds%2Fib.c;h=b12a3951167dc2f264c465ee4923a98ef98510be;hb=41f4a6f71fe33faa7971c173c263fb431fe987fe;hp=8f2d6dd7700a8a0e20192b521c30dc7bc2df553b;hpb=1d7aec304147aadcbc66ef9ab691208f9f22b6a8;p=mv-sheeva.git diff --git a/net/rds/ib.c b/net/rds/ib.c index 8f2d6dd7700..b12a3951167 100644 --- a/net/rds/ib.c +++ b/net/rds/ib.c @@ -53,12 +53,71 @@ MODULE_PARM_DESC(fmr_message_size, " Max size of a RDMA transfer"); 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; @@ -77,11 +136,14 @@ void rds_ib_add_one(struct ib_device *device) 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); @@ -91,68 +153,107 @@ void rds_ib_add_one(struct ib_device *device) 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 = { @@ -186,7 +287,7 @@ static int rds_ib_conn_info_visitor(struct rds_connection *conn, 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; @@ -248,29 +349,36 @@ static int rds_ib_laddr_check(__be32 addr) 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, @@ -286,16 +394,20 @@ struct rds_transport rds_ib_transport = { .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; @@ -317,7 +429,9 @@ out_recv: 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; }