/* * Copyright (c) 2007 Cisco Systems, 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 #include #include #include "mlx4_ib.h" #include "user.h" enum { MLX4_IB_ACK_REQ_FREQ = 8, }; enum { MLX4_IB_DEFAULT_SCHED_QUEUE = 0x83, MLX4_IB_DEFAULT_QP0_SCHED_QUEUE = 0x3f }; enum { /* * Largest possible UD header: send with GRH and immediate data. */ MLX4_IB_UD_HEADER_SIZE = 72 }; struct mlx4_ib_sqp { struct mlx4_ib_qp qp; int pkey_index; u32 qkey; u32 send_psn; struct ib_ud_header ud_header; u8 header_buf[MLX4_IB_UD_HEADER_SIZE]; }; static const __be32 mlx4_ib_opcode[] = { [IB_WR_SEND] = __constant_cpu_to_be32(MLX4_OPCODE_SEND), [IB_WR_SEND_WITH_IMM] = __constant_cpu_to_be32(MLX4_OPCODE_SEND_IMM), [IB_WR_RDMA_WRITE] = __constant_cpu_to_be32(MLX4_OPCODE_RDMA_WRITE), [IB_WR_RDMA_WRITE_WITH_IMM] = __constant_cpu_to_be32(MLX4_OPCODE_RDMA_WRITE_IMM), [IB_WR_RDMA_READ] = __constant_cpu_to_be32(MLX4_OPCODE_RDMA_READ), [IB_WR_ATOMIC_CMP_AND_SWP] = __constant_cpu_to_be32(MLX4_OPCODE_ATOMIC_CS), [IB_WR_ATOMIC_FETCH_AND_ADD] = __constant_cpu_to_be32(MLX4_OPCODE_ATOMIC_FA), }; static struct mlx4_ib_sqp *to_msqp(struct mlx4_ib_qp *mqp) { return container_of(mqp, struct mlx4_ib_sqp, qp); } static int is_sqp(struct mlx4_ib_dev *dev, struct mlx4_ib_qp *qp) { return qp->mqp.qpn >= dev->dev->caps.sqp_start && qp->mqp.qpn <= dev->dev->caps.sqp_start + 3; } static int is_qp0(struct mlx4_ib_dev *dev, struct mlx4_ib_qp *qp) { return qp->mqp.qpn >= dev->dev->caps.sqp_start && qp->mqp.qpn <= dev->dev->caps.sqp_start + 1; } static void *get_wqe(struct mlx4_ib_qp *qp, int offset) { if (qp->buf.nbufs == 1) return qp->buf.u.direct.buf + offset; else return qp->buf.u.page_list[offset >> PAGE_SHIFT].buf + (offset & (PAGE_SIZE - 1)); } static void *get_recv_wqe(struct mlx4_ib_qp *qp, int n) { return get_wqe(qp, qp->rq.offset + (n << qp->rq.wqe_shift)); } static void *get_send_wqe(struct mlx4_ib_qp *qp, int n) { return get_wqe(qp, qp->sq.offset + (n << qp->sq.wqe_shift)); } static void mlx4_ib_qp_event(struct mlx4_qp *qp, enum mlx4_event type) { struct ib_event event; struct ib_qp *ibqp = &to_mibqp(qp)->ibqp; if (type == MLX4_EVENT_TYPE_PATH_MIG) to_mibqp(qp)->port = to_mibqp(qp)->alt_port; if (ibqp->event_handler) { event.device = ibqp->device; event.element.qp = ibqp; switch (type) { case MLX4_EVENT_TYPE_PATH_MIG: event.event = IB_EVENT_PATH_MIG; break; case MLX4_EVENT_TYPE_COMM_EST: event.event = IB_EVENT_COMM_EST; break; case MLX4_EVENT_TYPE_SQ_DRAINED: event.event = IB_EVENT_SQ_DRAINED; break; case MLX4_EVENT_TYPE_SRQ_QP_LAST_WQE: event.event = IB_EVENT_QP_LAST_WQE_REACHED; break; case MLX4_EVENT_TYPE_WQ_CATAS_ERROR: event.event = IB_EVENT_QP_FATAL; break; case MLX4_EVENT_TYPE_PATH_MIG_FAILED: event.event = IB_EVENT_PATH_MIG_ERR; break; case MLX4_EVENT_TYPE_WQ_INVAL_REQ_ERROR: event.event = IB_EVENT_QP_REQ_ERR; break; case MLX4_EVENT_TYPE_WQ_ACCESS_ERROR: event.event = IB_EVENT_QP_ACCESS_ERR; break; default: printk(KERN_WARNING "mlx4_ib: Unexpected event type %d " "on QP %06x\n", type, qp->qpn); return; } ibqp->event_handler(&event, ibqp->qp_context); } } static int send_wqe_overhead(enum ib_qp_type type) { /* * UD WQEs must have a datagram segment. * RC and UC WQEs might have a remote address segment. * MLX WQEs need two extra inline data segments (for the UD * header and space for the ICRC). */ switch (type) { case IB_QPT_UD: return sizeof (struct mlx4_wqe_ctrl_seg) + sizeof (struct mlx4_wqe_datagram_seg); case IB_QPT_UC: return sizeof (struct mlx4_wqe_ctrl_seg) + sizeof (struct mlx4_wqe_raddr_seg); case IB_QPT_RC: return sizeof (struct mlx4_wqe_ctrl_seg) + sizeof (struct mlx4_wqe_atomic_seg) + sizeof (struct mlx4_wqe_raddr_seg); case IB_QPT_SMI: case IB_QPT_GSI: return sizeof (struct mlx4_wqe_ctrl_seg) + ALIGN(MLX4_IB_UD_HEADER_SIZE + sizeof (struct mlx4_wqe_inline_seg), sizeof (struct mlx4_wqe_data_seg)) + ALIGN(4 + sizeof (struct mlx4_wqe_inline_seg), sizeof (struct mlx4_wqe_data_seg)); default: return sizeof (struct mlx4_wqe_ctrl_seg); } } static int set_rq_size(struct mlx4_ib_dev *dev, struct ib_qp_cap *cap, struct mlx4_ib_qp *qp) { /* Sanity check RQ size before proceeding */ if (cap->max_recv_wr > dev->dev->caps.max_wqes || cap->max_recv_sge > dev->dev->caps.max_rq_sg) return -EINVAL; qp->rq.max = cap->max_recv_wr ? roundup_pow_of_two(cap->max_recv_wr) : 0; qp->rq.wqe_shift = ilog2(roundup_pow_of_two(cap->max_recv_sge * sizeof (struct mlx4_wqe_data_seg))); qp->rq.max_gs = (1 << qp->rq.wqe_shift) / sizeof (struct mlx4_wqe_data_seg); cap->max_recv_wr = qp->rq.max; cap->max_recv_sge = qp->rq.max_gs; return 0; } static int set_kernel_sq_size(struct mlx4_ib_dev *dev, struct ib_qp_cap *cap, enum ib_qp_type type, struct mlx4_ib_qp *qp) { /* Sanity check SQ size before proceeding */ if (cap->max_send_wr > dev->dev->caps.max_wqes || cap->max_send_sge > dev->dev->caps.max_sq_sg || cap->max_inline_data + send_wqe_overhead(type) + sizeof (struct mlx4_wqe_inline_seg) > dev->dev->caps.max_sq_desc_sz) return -EINVAL; /* * For MLX transport we need 2 extra S/G entries: * one for the header and one for the checksum at the end */ if ((type == IB_QPT_SMI || type == IB_QPT_GSI) && cap->max_send_sge + 2 > dev->dev->caps.max_sq_sg) return -EINVAL; qp->sq.max = cap->max_send_wr ? roundup_pow_of_two(cap->max_send_wr) : 1; qp->sq.wqe_shift = ilog2(roundup_pow_of_two(max(cap->max_send_sge * sizeof (struct mlx4_wqe_data_seg), cap->max_inline_data + sizeof (struct mlx4_wqe_inline_seg)) + send_wqe_overhead(type))); qp->sq.max_gs = ((1 << qp->sq.wqe_shift) - send_wqe_overhead(type)) / sizeof (struct mlx4_wqe_data_seg); qp->buf_size = (qp->rq.max << qp->rq.wqe_shift) + (qp->sq.max << qp->sq.wqe_shift); if (qp->rq.wqe_shift > qp->sq.wqe_shift) { qp->rq.offset = 0; qp->sq.offset = qp->rq.max << qp->rq.wqe_shift; } else { qp->rq.offset = qp->sq.max << qp->sq.wqe_shift; qp->sq.offset = 0; } cap->max_send_wr = qp->sq.max; cap->max_send_sge = qp->sq.max_gs; cap->max_inline_data = (1 << qp->sq.wqe_shift) - send_wqe_overhead(type) - sizeof (struct mlx4_wqe_inline_seg); return 0; } static int set_user_sq_size(struct mlx4_ib_qp *qp, struct mlx4_ib_create_qp *ucmd) { qp->sq.max = 1 << ucmd->log_sq_bb_count; qp->sq.wqe_shift = ucmd->log_sq_stride; qp->buf_size = (qp->rq.max << qp->rq.wqe_shift) + (qp->sq.max << qp->sq.wqe_shift); return 0; } static int create_qp_common(struct mlx4_ib_dev *dev, struct ib_pd *pd, struct ib_qp_init_attr *init_attr, struct ib_udata *udata, int sqpn, struct mlx4_ib_qp *qp) { int err; mutex_init(&qp->mutex); spin_lock_init(&qp->sq.lock); spin_lock_init(&qp->rq.lock); qp->state = IB_QPS_RESET; qp->atomic_rd_en = 0; qp->resp_depth = 0; qp->rq.head = 0; qp->rq.tail = 0; qp->sq.head = 0; qp->sq.tail = 0; err = set_rq_size(dev, &init_attr->cap, qp); if (err) goto err; if (pd->uobject) { struct mlx4_ib_create_qp ucmd; if (ib_copy_from_udata(&ucmd, udata, sizeof ucmd)) { err = -EFAULT; goto err; } err = set_user_sq_size(qp, &ucmd); if (err) goto err; qp->umem = ib_umem_get(pd->uobject->context, ucmd.buf_addr, qp->buf_size, 0); if (IS_ERR(qp->umem)) { err = PTR_ERR(qp->umem); goto err; } err = mlx4_mtt_init(dev->dev, ib_umem_page_count(qp->umem), ilog2(qp->umem->page_size), &qp->mtt); if (err) goto err_buf; err = mlx4_ib_umem_write_mtt(dev, &qp->mtt, qp->umem); if (err) goto err_mtt; if (!init_attr->srq) { err = mlx4_ib_db_map_user(to_mucontext(pd->uobject->context), ucmd.db_addr, &qp->db); if (err) goto err_mtt; } } else { err = set_kernel_sq_size(dev, &init_attr->cap, init_attr->qp_type, qp); if (err) goto err; if (!init_attr->srq) { err = mlx4_ib_db_alloc(dev, &qp->db, 0); if (err) goto err; *qp->db.db = 0; } if (mlx4_buf_alloc(dev->dev, qp->buf_size, PAGE_SIZE * 2, &qp->buf)) { err = -ENOMEM; goto err_db; } err = mlx4_mtt_init(dev->dev, qp->buf.npages, qp->buf.page_shift, &qp->mtt); if (err) goto err_buf; err = mlx4_buf_write_mtt(dev->dev, &qp->mtt, &qp->buf); if (err) goto err_mtt; qp->sq.wrid = kmalloc(qp->sq.max * sizeof (u64), GFP_KERNEL); qp->rq.wrid = kmalloc(qp->rq.max * sizeof (u64), GFP_KERNEL); if (!qp->sq.wrid || !qp->rq.wrid) { err = -ENOMEM; goto err_wrid; } /* We don't support inline sends for kernel QPs (yet) */ init_attr->cap.max_inline_data = 0; } err = mlx4_qp_alloc(dev->dev, sqpn, &qp->mqp); if (err) goto err_wrid; /* * Hardware wants QPN written in big-endian order (after * shifting) for send doorbell. Precompute this value to save * a little bit when posting sends. */ qp->doorbell_qpn = swab32(qp->mqp.qpn << 8); if (init_attr->sq_sig_type == IB_SIGNAL_ALL_WR) qp->sq_signal_bits = cpu_to_be32(MLX4_WQE_CTRL_CQ_UPDATE); else qp->sq_signal_bits = 0; qp->mqp.event = mlx4_ib_qp_event; return 0; err_wrid: if (pd->uobject && !init_attr->srq) mlx4_ib_db_unmap_user(to_mucontext(pd->uobject->context), &qp->db); else { kfree(qp->sq.wrid); kfree(qp->rq.wrid); } err_mtt: mlx4_mtt_cleanup(dev->dev, &qp->mtt); err_buf: if (pd->uobject) ib_umem_release(qp->umem); else mlx4_buf_free(dev->dev, qp->buf_size, &qp->buf); err_db: if (!pd->uobject && !init_attr->srq) mlx4_ib_db_free(dev, &qp->db); err: return err; } static enum mlx4_qp_state to_mlx4_state(enum ib_qp_state state) { switch (state) { case IB_QPS_RESET: return MLX4_QP_STATE_RST; case IB_QPS_INIT: return MLX4_QP_STATE_INIT; case IB_QPS_RTR: return MLX4_QP_STATE_RTR; case IB_QPS_RTS: return MLX4_QP_STATE_RTS; case IB_QPS_SQD: return MLX4_QP_STATE_SQD; case IB_QPS_SQE: return MLX4_QP_STATE_SQER; case IB_QPS_ERR: return MLX4_QP_STATE_ERR; default: return -1; } } static void mlx4_ib_lock_cqs(struct mlx4_ib_cq *send_cq, struct mlx4_ib_cq *recv_cq) { if (send_cq == recv_cq) spin_lock_irq(&send_cq->lock); else if (send_cq->mcq.cqn < recv_cq->mcq.cqn) { spin_lock_irq(&send_cq->lock); spin_lock_nested(&recv_cq->lock, SINGLE_DEPTH_NESTING); } else { spin_lock_irq(&recv_cq->lock); spin_lock_nested(&send_cq->lock, SINGLE_DEPTH_NESTING); } } static void mlx4_ib_unlock_cqs(struct mlx4_ib_cq *send_cq, struct mlx4_ib_cq *recv_cq) { if (send_cq == recv_cq) spin_unlock_irq(&send_cq->lock); else if (send_cq->mcq.cqn < recv_cq->mcq.cqn) { spin_unlock(&recv_cq->lock); spin_unlock_irq(&send_cq->lock); } else { spin_unlock(&send_cq->lock); spin_unlock_irq(&recv_cq->lock); } } static void destroy_qp_common(struct mlx4_ib_dev *dev, struct mlx4_ib_qp *qp, int is_user) { struct mlx4_ib_cq *send_cq, *recv_cq; if (qp->state != IB_QPS_RESET) if (mlx4_qp_modify(dev->dev, NULL, to_mlx4_state(qp->state), MLX4_QP_STATE_RST, NULL, 0, 0, &qp->mqp)) printk(KERN_WARNING "mlx4_ib: modify QP %06x to RESET failed.\n", qp->mqp.qpn); send_cq = to_mcq(qp->ibqp.send_cq); recv_cq = to_mcq(qp->ibqp.recv_cq); mlx4_ib_lock_cqs(send_cq, recv_cq); if (!is_user) { __mlx4_ib_cq_clean(recv_cq, qp->mqp.qpn, qp->ibqp.srq ? to_msrq(qp->ibqp.srq): NULL); if (send_cq != recv_cq) __mlx4_ib_cq_clean(send_cq, qp->mqp.qpn, NULL); } mlx4_qp_remove(dev->dev, &qp->mqp); mlx4_ib_unlock_cqs(send_cq, recv_cq); mlx4_qp_free(dev->dev, &qp->mqp); mlx4_mtt_cleanup(dev->dev, &qp->mtt); if (is_user) { if (!qp->ibqp.srq) mlx4_ib_db_unmap_user(to_mucontext(qp->ibqp.uobject->context), &qp->db); ib_umem_release(qp->umem); } else { kfree(qp->sq.wrid); kfree(qp->rq.wrid); mlx4_buf_free(dev->dev, qp->buf_size, &qp->buf); if (!qp->ibqp.srq) mlx4_ib_db_free(dev, &qp->db); } } struct ib_qp *mlx4_ib_create_qp(struct ib_pd *pd, struct ib_qp_init_attr *init_attr, struct ib_udata *udata) { struct mlx4_ib_dev *dev = to_mdev(pd->device); struct mlx4_ib_sqp *sqp; struct mlx4_ib_qp *qp; int err; switch (init_attr->qp_type) { case IB_QPT_RC: case IB_QPT_UC: case IB_QPT_UD: { qp = kmalloc(sizeof *qp, GFP_KERNEL); if (!qp) return ERR_PTR(-ENOMEM); err = create_qp_common(dev, pd, init_attr, udata, 0, qp); if (err) { kfree(qp); return ERR_PTR(err); } qp->ibqp.qp_num = qp->mqp.qpn; break; } case IB_QPT_SMI: case IB_QPT_GSI: { /* Userspace is not allowed to create special QPs: */ if (pd->uobject) return ERR_PTR(-EINVAL); sqp = kmalloc(sizeof *sqp, GFP_KERNEL); if (!sqp) return ERR_PTR(-ENOMEM); qp = &sqp->qp; err = create_qp_common(dev, pd, init_attr, udata, dev->dev->caps.sqp_start + (init_attr->qp_type == IB_QPT_SMI ? 0 : 2) + init_attr->port_num - 1, qp); if (err) { kfree(sqp); return ERR_PTR(err); } qp->port = init_attr->port_num; qp->ibqp.qp_num = init_attr->qp_type == IB_QPT_SMI ? 0 : 1; break; } default: /* Don't support raw QPs */ return ERR_PTR(-EINVAL); } return &qp->ibqp; } int mlx4_ib_destroy_qp(struct ib_qp *qp) { struct mlx4_ib_dev *dev = to_mdev(qp->device); struct mlx4_ib_qp *mqp = to_mqp(qp); if (is_qp0(dev, mqp)) mlx4_CLOSE_PORT(dev->dev, mqp->port); destroy_qp_common(dev, mqp, !!qp->pd->uobject); if (is_sqp(dev, mqp)) kfree(to_msqp(mqp)); else kfree(mqp); return 0; } static void init_port(struct mlx4_ib_dev *dev, int port) { struct mlx4_init_port_param param; int err; memset(¶m, 0, sizeof param); param.port_width_cap = dev->dev->caps.port_width_cap; param.vl_cap = dev->dev->caps.vl_cap; param.mtu = ib_mtu_enum_to_int(dev->dev->caps.mtu_cap); param.max_gid = dev->dev->caps.gid_table_len; param.max_pkey = dev->dev->caps.pkey_table_len; err = mlx4_INIT_PORT(dev->dev, ¶m, port); if (err) printk(KERN_WARNING "INIT_PORT failed, return code %d.\n", err); } static int to_mlx4_st(enum ib_qp_type type) { switch (type) { case IB_QPT_RC: return MLX4_QP_ST_RC; case IB_QPT_UC: return MLX4_QP_ST_UC; case IB_QPT_UD: return MLX4_QP_ST_UD; case IB_QPT_SMI: case IB_QPT_GSI: return MLX4_QP_ST_MLX; default: return -1; } } static __be32 to_mlx4_access_flags(struct mlx4_ib_qp *qp, const struct ib_qp_attr *attr, int attr_mask) { u8 dest_rd_atomic; u32 access_flags; u32 hw_access_flags = 0; if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC) dest_rd_atomic = attr->max_dest_rd_atomic; else dest_rd_atomic = qp->resp_depth; if (attr_mask & IB_QP_ACCESS_FLAGS) access_flags = attr->qp_access_flags; else access_flags = qp->atomic_rd_en; if (!dest_rd_atomic) access_flags &= IB_ACCESS_REMOTE_WRITE; if (access_flags & IB_ACCESS_REMOTE_READ) hw_access_flags |= MLX4_QP_BIT_RRE; if (access_flags & IB_ACCESS_REMOTE_ATOMIC) hw_access_flags |= MLX4_QP_BIT_RAE; if (access_flags & IB_ACCESS_REMOTE_WRITE) hw_access_flags |= MLX4_QP_BIT_RWE; return cpu_to_be32(hw_access_flags); } static void store_sqp_attrs(struct mlx4_ib_sqp *sqp, const struct ib_qp_attr *attr, int attr_mask) { if (attr_mask & IB_QP_PKEY_INDEX) sqp->pkey_index = attr->pkey_index; if (attr_mask & IB_QP_QKEY) sqp->qkey = attr->qkey; if (attr_mask & IB_QP_SQ_PSN) sqp->send_psn = attr->sq_psn; } static void mlx4_set_sched(struct mlx4_qp_path *path, u8 port) { path->sched_queue = (path->sched_queue & 0xbf) | ((port - 1) << 6); } static int mlx4_set_path(struct mlx4_ib_dev *dev, const struct ib_ah_attr *ah, struct mlx4_qp_path *path, u8 port) { path->grh_mylmc = ah->src_path_bits & 0x7f; path->rlid = cpu_to_be16(ah->dlid); if (ah->static_rate) { path->static_rate = ah->static_rate + MLX4_STAT_RATE_OFFSET; while (path->static_rate > IB_RATE_2_5_GBPS + MLX4_STAT_RATE_OFFSET && !(1 << path->static_rate & dev->dev->caps.stat_rate_support)) --path->static_rate; } else path->static_rate = 0; path->counter_index = 0xff; if (ah->ah_flags & IB_AH_GRH) { if (ah->grh.sgid_index >= dev->dev->caps.gid_table_len) { printk(KERN_ERR "sgid_index (%u) too large. max is %d\n", ah->grh.sgid_index, dev->dev->caps.gid_table_len - 1); return -1; } path->grh_mylmc |= 1 << 7; path->mgid_index = ah->grh.sgid_index; path->hop_limit = ah->grh.hop_limit; path->tclass_flowlabel = cpu_to_be32((ah->grh.traffic_class << 20) | (ah->grh.flow_label)); memcpy(path->rgid, ah->grh.dgid.raw, 16); } path->sched_queue = MLX4_IB_DEFAULT_SCHED_QUEUE | ((port - 1) << 6) | ((ah->sl & 0xf) << 2); return 0; } static int __mlx4_ib_modify_qp(struct ib_qp *ibqp, const struct ib_qp_attr *attr, int attr_mask, enum ib_qp_state cur_state, enum ib_qp_state new_state) { struct mlx4_ib_dev *dev = to_mdev(ibqp->device); struct mlx4_ib_qp *qp = to_mqp(ibqp); struct mlx4_qp_context *context; enum mlx4_qp_optpar optpar = 0; int sqd_event; int err = -EINVAL; context = kzalloc(sizeof *context, GFP_KERNEL); if (!context) return -ENOMEM; context->flags = cpu_to_be32((to_mlx4_state(new_state) << 28) | (to_mlx4_st(ibqp->qp_type) << 16)); context->flags |= cpu_to_be32(1 << 8); /* DE? */ if (!(attr_mask & IB_QP_PATH_MIG_STATE)) context->flags |= cpu_to_be32(MLX4_QP_PM_MIGRATED << 11); else { optpar |= MLX4_QP_OPTPAR_PM_STATE; switch (attr->path_mig_state) { case IB_MIG_MIGRATED: context->flags |= cpu_to_be32(MLX4_QP_PM_MIGRATED << 11); break; case IB_MIG_REARM: context->flags |= cpu_to_be32(MLX4_QP_PM_REARM << 11); break; case IB_MIG_ARMED: context->flags |= cpu_to_be32(MLX4_QP_PM_ARMED << 11); break; } } if (ibqp->qp_type == IB_QPT_GSI || ibqp->qp_type == IB_QPT_SMI || ibqp->qp_type == IB_QPT_UD) context->mtu_msgmax = (IB_MTU_4096 << 5) | 11; else if (attr_mask & IB_QP_PATH_MTU) { if (attr->path_mtu < IB_MTU_256 || attr->path_mtu > IB_MTU_4096) { printk(KERN_ERR "path MTU (%u) is invalid\n", attr->path_mtu); return -EINVAL; } context->mtu_msgmax = (attr->path_mtu << 5) | 31; } if (qp->rq.max) context->rq_size_stride = ilog2(qp->rq.max) << 3; context->rq_size_stride |= qp->rq.wqe_shift - 4; if (qp->sq.max) context->sq_size_stride = ilog2(qp->sq.max) << 3; context->sq_size_stride |= qp->sq.wqe_shift - 4; if (qp->ibqp.uobject) context->usr_page = cpu_to_be32(to_mucontext(ibqp->uobject->context)->uar.index); else context->usr_page = cpu_to_be32(dev->priv_uar.index); if (attr_mask & IB_QP_DEST_QPN) context->remote_qpn = cpu_to_be32(attr->dest_qp_num); if (attr_mask & IB_QP_PORT) { if (cur_state == IB_QPS_SQD && new_state == IB_QPS_SQD && !(attr_mask & IB_QP_AV)) { mlx4_set_sched(&context->pri_path, attr->port_num); optpar |= MLX4_QP_OPTPAR_SCHED_QUEUE; } } if (attr_mask & IB_QP_PKEY_INDEX) { context->pri_path.pkey_index = attr->pkey_index; optpar |= MLX4_QP_OPTPAR_PKEY_INDEX; } if (attr_mask & IB_QP_RNR_RETRY) { context->params1 |= cpu_to_be32(attr->rnr_retry << 13); optpar |= MLX4_QP_OPTPAR_RNR_RETRY; } if (attr_mask & IB_QP_AV) { if (mlx4_set_path(dev, &attr->ah_attr, &context->pri_path, attr_mask & IB_QP_PORT ? attr->port_num : qp->port)) { err = -EINVAL; goto out; } optpar |= (MLX4_QP_OPTPAR_PRIMARY_ADDR_PATH | MLX4_QP_OPTPAR_SCHED_QUEUE); } if (attr_mask & IB_QP_TIMEOUT) { context->pri_path.ackto = attr->timeout << 3; optpar |= MLX4_QP_OPTPAR_ACK_TIMEOUT; } if (attr_mask & IB_QP_ALT_PATH) { if (attr->alt_pkey_index >= dev->dev->caps.pkey_table_len) return -EINVAL; if (attr->alt_port_num == 0 || attr->alt_port_num > dev->dev->caps.num_ports) return -EINVAL; if (mlx4_set_path(dev, &attr->alt_ah_attr, &context->alt_path, attr->alt_port_num)) return -EINVAL; context->alt_path.pkey_index = attr->alt_pkey_index; context->alt_path.ackto = attr->alt_timeout << 3; optpar |= MLX4_QP_OPTPAR_ALT_ADDR_PATH; } context->pd = cpu_to_be32(to_mpd(ibqp->pd)->pdn); context->params1 = cpu_to_be32(MLX4_IB_ACK_REQ_FREQ << 28); if (attr_mask & IB_QP_RETRY_CNT) { context->params1 |= cpu_to_be32(attr->retry_cnt << 16); optpar |= MLX4_QP_OPTPAR_RETRY_COUNT; } if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC) { if (attr->max_rd_atomic) context->params1 |= cpu_to_be32(fls(attr->max_rd_atomic - 1) << 21); optpar |= MLX4_QP_OPTPAR_SRA_MAX; } if (attr_mask & IB_QP_SQ_PSN) context->next_send_psn = cpu_to_be32(attr->sq_psn); context->cqn_send = cpu_to_be32(to_mcq(ibqp->send_cq)->mcq.cqn); if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC) { if (attr->max_dest_rd_atomic) context->params2 |= cpu_to_be32(fls(attr->max_dest_rd_atomic - 1) << 21); optpar |= MLX4_QP_OPTPAR_RRA_MAX; } if (attr_mask & (IB_QP_ACCESS_FLAGS | IB_QP_MAX_DEST_RD_ATOMIC)) { context->params2 |= to_mlx4_access_flags(qp, attr, attr_mask); optpar |= MLX4_QP_OPTPAR_RWE | MLX4_QP_OPTPAR_RRE | MLX4_QP_OPTPAR_RAE; } if (ibqp->srq) context->params2 |= cpu_to_be32(MLX4_QP_BIT_RIC); if (attr_mask & IB_QP_MIN_RNR_TIMER) { context->rnr_nextrecvpsn |= cpu_to_be32(attr->min_rnr_timer << 24); optpar |= MLX4_QP_OPTPAR_RNR_TIMEOUT; } if (attr_mask & IB_QP_RQ_PSN) context->rnr_nextrecvpsn |= cpu_to_be32(attr->rq_psn); context->cqn_recv = cpu_to_be32(to_mcq(ibqp->recv_cq)->mcq.cqn); if (attr_mask & IB_QP_QKEY) { context->qkey = cpu_to_be32(attr->qkey); optpar |= MLX4_QP_OPTPAR_Q_KEY; } if (ibqp->srq) context->srqn = cpu_to_be32(1 << 24 | to_msrq(ibqp->srq)->msrq.srqn); if (!ibqp->srq && cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT) context->db_rec_addr = cpu_to_be64(qp->db.dma); if (cur_state == IB_QPS_INIT && new_state == IB_QPS_RTR && (ibqp->qp_type == IB_QPT_GSI || ibqp->qp_type == IB_QPT_SMI || ibqp->qp_type == IB_QPT_UD)) { context->pri_path.sched_queue = (qp->port - 1) << 6; if (is_qp0(dev, qp)) context->pri_path.sched_queue |= MLX4_IB_DEFAULT_QP0_SCHED_QUEUE; else context->pri_path.sched_queue |= MLX4_IB_DEFAULT_SCHED_QUEUE; } if (cur_state == IB_QPS_RTS && new_state == IB_QPS_SQD && attr_mask & IB_QP_EN_SQD_ASYNC_NOTIFY && attr->en_sqd_async_notify) sqd_event = 1; else sqd_event = 0; /* * Before passing a kernel QP to the HW, make sure that the * ownership bits of the send queue are set so that the * hardware doesn't start processing stale work requests. */ if (!ibqp->uobject && cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT) { struct mlx4_wqe_ctrl_seg *ctrl; int i; for (i = 0; i < qp->sq.max; ++i) { ctrl = get_send_wqe(qp, i); ctrl->owner_opcode = cpu_to_be32(1 << 31); } } err = mlx4_qp_modify(dev->dev, &qp->mtt, to_mlx4_state(cur_state), to_mlx4_state(new_state), context, optpar, sqd_event, &qp->mqp); if (err) goto out; qp->state = new_state; if (attr_mask & IB_QP_ACCESS_FLAGS) qp->atomic_rd_en = attr->qp_access_flags; if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC) qp->resp_depth = attr->max_dest_rd_atomic; if (attr_mask & IB_QP_PORT) qp->port = attr->port_num; if (attr_mask & IB_QP_ALT_PATH) qp->alt_port = attr->alt_port_num; if (is_sqp(dev, qp)) store_sqp_attrs(to_msqp(qp), attr, attr_mask); /* * If we moved QP0 to RTR, bring the IB link up; if we moved * QP0 to RESET or ERROR, bring the link back down. */ if (is_qp0(dev, qp)) { if (cur_state != IB_QPS_RTR && new_state == IB_QPS_RTR) init_port(dev, qp->port); if (cur_state != IB_QPS_RESET && cur_state != IB_QPS_ERR && (new_state == IB_QPS_RESET || new_state == IB_QPS_ERR)) mlx4_CLOSE_PORT(dev->dev, qp->port); } /* * If we moved a kernel QP to RESET, clean up all old CQ * entries and reinitialize the QP. */ if (new_state == IB_QPS_RESET && !ibqp->uobject) { mlx4_ib_cq_clean(to_mcq(ibqp->recv_cq), qp->mqp.qpn, ibqp->srq ? to_msrq(ibqp->srq): NULL); if (ibqp->send_cq != ibqp->recv_cq) mlx4_ib_cq_clean(to_mcq(ibqp->send_cq), qp->mqp.qpn, NULL); qp->rq.head = 0; qp->rq.tail = 0; qp->sq.head = 0; qp->sq.tail = 0; if (!ibqp->srq) *qp->db.db = 0; } out: kfree(context); return err; } static const struct ib_qp_attr mlx4_ib_qp_attr = { .port_num = 1 }; static const int mlx4_ib_qp_attr_mask_table[IB_QPT_UD + 1] = { [IB_QPT_UD] = (IB_QP_PKEY_INDEX | IB_QP_PORT | IB_QP_QKEY), [IB_QPT_UC] = (IB_QP_PKEY_INDEX | IB_QP_PORT | IB_QP_ACCESS_FLAGS), [IB_QPT_RC] = (IB_QP_PKEY_INDEX | IB_QP_PORT | IB_QP_ACCESS_FLAGS), [IB_QPT_SMI] = (IB_QP_PKEY_INDEX | IB_QP_QKEY), [IB_QPT_GSI] = (IB_QP_PKEY_INDEX | IB_QP_QKEY), }; int mlx4_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask, struct ib_udata *udata) { struct mlx4_ib_dev *dev = to_mdev(ibqp->device); struct mlx4_ib_qp *qp = to_mqp(ibqp); enum ib_qp_state cur_state, new_state; int err = -EINVAL; mutex_lock(&qp->mutex); cur_state = attr_mask & IB_QP_CUR_STATE ? attr->cur_qp_state : qp->state; new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state; if (!ib_modify_qp_is_ok(cur_state, new_state, ibqp->qp_type, attr_mask)) goto out; if ((attr_mask & IB_QP_PKEY_INDEX) && attr->pkey_index >= dev->dev->caps.pkey_table_len) { goto out; } if ((attr_mask & IB_QP_PORT) && (attr->port_num == 0 || attr->port_num > dev->dev->caps.num_ports)) { goto out; } if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC && attr->max_rd_atomic > dev->dev->caps.max_qp_init_rdma) { goto out; } if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC && attr->max_dest_rd_atomic > dev->dev->caps.max_qp_dest_rdma) { goto out; } if (cur_state == new_state && cur_state == IB_QPS_RESET) { err = 0; goto out; } if (cur_state == IB_QPS_RESET && new_state == IB_QPS_ERR) { err = __mlx4_ib_modify_qp(ibqp, &mlx4_ib_qp_attr, mlx4_ib_qp_attr_mask_table[ibqp->qp_type], IB_QPS_RESET, IB_QPS_INIT); if (err) goto out; cur_state = IB_QPS_INIT; } err = __mlx4_ib_modify_qp(ibqp, attr, attr_mask, cur_state, new_state); out: mutex_unlock(&qp->mutex); return err; } static int build_mlx_header(struct mlx4_ib_sqp *sqp, struct ib_send_wr *wr, void *wqe) { struct ib_device *ib_dev = &to_mdev(sqp->qp.ibqp.device)->ib_dev; struct mlx4_wqe_mlx_seg *mlx = wqe; struct mlx4_wqe_inline_seg *inl = wqe + sizeof *mlx; struct mlx4_ib_ah *ah = to_mah(wr->wr.ud.ah); u16 pkey; int send_size; int header_size; int i; send_size = 0; for (i = 0; i < wr->num_sge; ++i) send_size += wr->sg_list[i].length; ib_ud_header_init(send_size, mlx4_ib_ah_grh_present(ah), &sqp->ud_header); sqp->ud_header.lrh.service_level = be32_to_cpu(ah->av.sl_tclass_flowlabel) >> 28; sqp->ud_header.lrh.destination_lid = ah->av.dlid; sqp->ud_header.lrh.source_lid = cpu_to_be16(ah->av.g_slid & 0x7f); if (mlx4_ib_ah_grh_present(ah)) { sqp->ud_header.grh.traffic_class = (be32_to_cpu(ah->av.sl_tclass_flowlabel) >> 20) & 0xff; sqp->ud_header.grh.flow_label = ah->av.sl_tclass_flowlabel & cpu_to_be32(0xfffff); sqp->ud_header.grh.hop_limit = ah->av.hop_limit; ib_get_cached_gid(ib_dev, be32_to_cpu(ah->av.port_pd) >> 24, ah->av.gid_index, &sqp->ud_header.grh.source_gid); memcpy(sqp->ud_header.grh.destination_gid.raw, ah->av.dgid, 16); } mlx->flags &= cpu_to_be32(MLX4_WQE_CTRL_CQ_UPDATE); mlx->flags |= cpu_to_be32((!sqp->qp.ibqp.qp_num ? MLX4_WQE_MLX_VL15 : 0) | (sqp->ud_header.lrh.destination_lid == IB_LID_PERMISSIVE ? MLX4_WQE_MLX_SLR : 0) | (sqp->ud_header.lrh.service_level << 8)); mlx->rlid = sqp->ud_header.lrh.destination_lid; switch (wr->opcode) { case IB_WR_SEND: sqp->ud_header.bth.opcode = IB_OPCODE_UD_SEND_ONLY; sqp->ud_header.immediate_present = 0; break; case IB_WR_SEND_WITH_IMM: sqp->ud_header.bth.opcode = IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE; sqp->ud_header.immediate_present = 1; sqp->ud_header.immediate_data = wr->imm_data; break; default: return -EINVAL; } sqp->ud_header.lrh.virtual_lane = !sqp->qp.ibqp.qp_num ? 15 : 0; if (sqp->ud_header.lrh.destination_lid == IB_LID_PERMISSIVE) sqp->ud_header.lrh.source_lid = IB_LID_PERMISSIVE; sqp->ud_header.bth.solicited_event = !!(wr->send_flags & IB_SEND_SOLICITED); if (!sqp->qp.ibqp.qp_num) ib_get_cached_pkey(ib_dev, sqp->qp.port, sqp->pkey_index, &pkey); else ib_get_cached_pkey(ib_dev, sqp->qp.port, wr->wr.ud.pkey_index, &pkey); sqp->ud_header.bth.pkey = cpu_to_be16(pkey); sqp->ud_header.bth.destination_qpn = cpu_to_be32(wr->wr.ud.remote_qpn); sqp->ud_header.bth.psn = cpu_to_be32((sqp->send_psn++) & ((1 << 24) - 1)); sqp->ud_header.deth.qkey = cpu_to_be32(wr->wr.ud.remote_qkey & 0x80000000 ? sqp->qkey : wr->wr.ud.remote_qkey); sqp->ud_header.deth.source_qpn = cpu_to_be32(sqp->qp.ibqp.qp_num); header_size = ib_ud_header_pack(&sqp->ud_header, sqp->header_buf); if (0) { printk(KERN_ERR "built UD header of size %d:\n", header_size); for (i = 0; i < header_size / 4; ++i) { if (i % 8 == 0) printk(" [%02x] ", i * 4); printk(" %08x", be32_to_cpu(((__be32 *) sqp->header_buf)[i])); if ((i + 1) % 8 == 0) printk("\n"); } printk("\n"); } inl->byte_count = cpu_to_be32(1 << 31 | header_size); memcpy(inl + 1, sqp->header_buf, header_size); return ALIGN(sizeof (struct mlx4_wqe_inline_seg) + header_size, 16); } static int mlx4_wq_overflow(struct mlx4_ib_wq *wq, int nreq, struct ib_cq *ib_cq) { unsigned cur; struct mlx4_ib_cq *cq; cur = wq->head - wq->tail; if (likely(cur + nreq < wq->max)) return 0; cq = to_mcq(ib_cq); spin_lock(&cq->lock); cur = wq->head - wq->tail; spin_unlock(&cq->lock); return cur + nreq >= wq->max; } int mlx4_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr, struct ib_send_wr **bad_wr) { struct mlx4_ib_qp *qp = to_mqp(ibqp); void *wqe; struct mlx4_wqe_ctrl_seg *ctrl; unsigned long flags; int nreq; int err = 0; int ind; int size; int i; spin_lock_irqsave(&qp->rq.lock, flags); ind = qp->sq.head; for (nreq = 0; wr; ++nreq, wr = wr->next) { if (mlx4_wq_overflow(&qp->sq, nreq, qp->ibqp.send_cq)) { err = -ENOMEM; *bad_wr = wr; goto out; } if (unlikely(wr->num_sge > qp->sq.max_gs)) { err = -EINVAL; *bad_wr = wr; goto out; } ctrl = wqe = get_send_wqe(qp, ind & (qp->sq.max - 1)); qp->sq.wrid[ind & (qp->sq.max - 1)] = wr->wr_id; ctrl->srcrb_flags = (wr->send_flags & IB_SEND_SIGNALED ? cpu_to_be32(MLX4_WQE_CTRL_CQ_UPDATE) : 0) | (wr->send_flags & IB_SEND_SOLICITED ? cpu_to_be32(MLX4_WQE_CTRL_SOLICITED) : 0) | qp->sq_signal_bits; if (wr->opcode == IB_WR_SEND_WITH_IMM || wr->opcode == IB_WR_RDMA_WRITE_WITH_IMM) ctrl->imm = wr->imm_data; else ctrl->imm = 0; wqe += sizeof *ctrl; size = sizeof *ctrl / 16; switch (ibqp->qp_type) { case IB_QPT_RC: case IB_QPT_UC: switch (wr->opcode) { case IB_WR_ATOMIC_CMP_AND_SWP: case IB_WR_ATOMIC_FETCH_AND_ADD: ((struct mlx4_wqe_raddr_seg *) wqe)->raddr = cpu_to_be64(wr->wr.atomic.remote_addr); ((struct mlx4_wqe_raddr_seg *) wqe)->rkey = cpu_to_be32(wr->wr.atomic.rkey); ((struct mlx4_wqe_raddr_seg *) wqe)->reserved = 0; wqe += sizeof (struct mlx4_wqe_raddr_seg); if (wr->opcode == IB_WR_ATOMIC_CMP_AND_SWP) { ((struct mlx4_wqe_atomic_seg *) wqe)->swap_add = cpu_to_be64(wr->wr.atomic.swap); ((struct mlx4_wqe_atomic_seg *) wqe)->compare = cpu_to_be64(wr->wr.atomic.compare_add); } else { ((struct mlx4_wqe_atomic_seg *) wqe)->swap_add = cpu_to_be64(wr->wr.atomic.compare_add); ((struct mlx4_wqe_atomic_seg *) wqe)->compare = 0; } wqe += sizeof (struct mlx4_wqe_atomic_seg); size += (sizeof (struct mlx4_wqe_raddr_seg) + sizeof (struct mlx4_wqe_atomic_seg)) / 16; break; case IB_WR_RDMA_READ: case IB_WR_RDMA_WRITE: case IB_WR_RDMA_WRITE_WITH_IMM: ((struct mlx4_wqe_raddr_seg *) wqe)->raddr = cpu_to_be64(wr->wr.rdma.remote_addr); ((struct mlx4_wqe_raddr_seg *) wqe)->rkey = cpu_to_be32(wr->wr.rdma.rkey); ((struct mlx4_wqe_raddr_seg *) wqe)->reserved = 0; wqe += sizeof (struct mlx4_wqe_raddr_seg); size += sizeof (struct mlx4_wqe_raddr_seg) / 16; break; default: /* No extra segments required for sends */ break; } break; case IB_QPT_UD: memcpy(((struct mlx4_wqe_datagram_seg *) wqe)->av, &to_mah(wr->wr.ud.ah)->av, sizeof (struct mlx4_av)); ((struct mlx4_wqe_datagram_seg *) wqe)->dqpn = cpu_to_be32(wr->wr.ud.remote_qpn); ((struct mlx4_wqe_datagram_seg *) wqe)->qkey = cpu_to_be32(wr->wr.ud.remote_qkey); wqe += sizeof (struct mlx4_wqe_datagram_seg); size += sizeof (struct mlx4_wqe_datagram_seg) / 16; break; case IB_QPT_SMI: case IB_QPT_GSI: err = build_mlx_header(to_msqp(qp), wr, ctrl); if (err < 0) { *bad_wr = wr; goto out; } wqe += err; size += err / 16; err = 0; break; default: break; } for (i = 0; i < wr->num_sge; ++i) { ((struct mlx4_wqe_data_seg *) wqe)->byte_count = cpu_to_be32(wr->sg_list[i].length); ((struct mlx4_wqe_data_seg *) wqe)->lkey = cpu_to_be32(wr->sg_list[i].lkey); ((struct mlx4_wqe_data_seg *) wqe)->addr = cpu_to_be64(wr->sg_list[i].addr); wqe += sizeof (struct mlx4_wqe_data_seg); size += sizeof (struct mlx4_wqe_data_seg) / 16; } /* Add one more inline data segment for ICRC for MLX sends */ if (qp->ibqp.qp_type == IB_QPT_SMI || qp->ibqp.qp_type == IB_QPT_GSI) { ((struct mlx4_wqe_inline_seg *) wqe)->byte_count = cpu_to_be32((1 << 31) | 4); ((u32 *) wqe)[1] = 0; wqe += sizeof (struct mlx4_wqe_data_seg); size += sizeof (struct mlx4_wqe_data_seg) / 16; } ctrl->fence_size = (wr->send_flags & IB_SEND_FENCE ? MLX4_WQE_CTRL_FENCE : 0) | size; /* * Make sure descriptor is fully written before * setting ownership bit (because HW can start * executing as soon as we do). */ wmb(); if (wr->opcode < 0 || wr->opcode >= ARRAY_SIZE(mlx4_ib_opcode)) { err = -EINVAL; goto out; } ctrl->owner_opcode = mlx4_ib_opcode[wr->opcode] | (ind & qp->sq.max ? cpu_to_be32(1 << 31) : 0); ++ind; } out: if (likely(nreq)) { qp->sq.head += nreq; /* * Make sure that descriptors are written before * doorbell record. */ wmb(); writel(qp->doorbell_qpn, to_mdev(ibqp->device)->uar_map + MLX4_SEND_DOORBELL); /* * Make sure doorbells don't leak out of SQ spinlock * and reach the HCA out of order. */ mmiowb(); } spin_unlock_irqrestore(&qp->rq.lock, flags); return err; } int mlx4_ib_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr, struct ib_recv_wr **bad_wr) { struct mlx4_ib_qp *qp = to_mqp(ibqp); struct mlx4_wqe_data_seg *scat; unsigned long flags; int err = 0; int nreq; int ind; int i; spin_lock_irqsave(&qp->rq.lock, flags); ind = qp->rq.head & (qp->rq.max - 1); for (nreq = 0; wr; ++nreq, wr = wr->next) { if (mlx4_wq_overflow(&qp->rq, nreq, qp->ibqp.send_cq)) { err = -ENOMEM; *bad_wr = wr; goto out; } if (unlikely(wr->num_sge > qp->rq.max_gs)) { err = -EINVAL; *bad_wr = wr; goto out; } scat = get_recv_wqe(qp, ind); for (i = 0; i < wr->num_sge; ++i) { scat[i].byte_count = cpu_to_be32(wr->sg_list[i].length); scat[i].lkey = cpu_to_be32(wr->sg_list[i].lkey); scat[i].addr = cpu_to_be64(wr->sg_list[i].addr); } if (i < qp->rq.max_gs) { scat[i].byte_count = 0; scat[i].lkey = cpu_to_be32(MLX4_INVALID_LKEY); scat[i].addr = 0; } qp->rq.wrid[ind] = wr->wr_id; ind = (ind + 1) & (qp->rq.max - 1); } out: if (likely(nreq)) { qp->rq.head += nreq; /* * Make sure that descriptors are written before * doorbell record. */ wmb(); *qp->db.db = cpu_to_be32(qp->rq.head & 0xffff); } spin_unlock_irqrestore(&qp->rq.lock, flags); return err; }