diff options
Diffstat (limited to 'drivers/infiniband/hw/qib/qib_rc.c')
| -rw-r--r-- | drivers/infiniband/hw/qib/qib_rc.c | 2288 |
1 files changed, 2288 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/qib/qib_rc.c b/drivers/infiniband/hw/qib/qib_rc.c new file mode 100644 index 0000000..40c0a37 --- /dev/null +++ b/drivers/infiniband/hw/qib/qib_rc.c @@ -0,0 +1,2288 @@ +/* + * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved. + * Copyright (c) 2005, 2006 PathScale, 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/io.h> + +#include "qib.h" + +/* cut down ridiculously long IB macro names */ +#define OP(x) IB_OPCODE_RC_##x + +static void rc_timeout(unsigned long arg); + +static u32 restart_sge(struct qib_sge_state *ss, struct qib_swqe *wqe, + u32 psn, u32 pmtu) +{ + u32 len; + + len = ((psn - wqe->psn) & QIB_PSN_MASK) * pmtu; + ss->sge = wqe->sg_list[0]; + ss->sg_list = wqe->sg_list + 1; + ss->num_sge = wqe->wr.num_sge; + ss->total_len = wqe->length; + qib_skip_sge(ss, len, 0); + return wqe->length - len; +} + +static void start_timer(struct qib_qp *qp) +{ + qp->s_flags |= QIB_S_TIMER; + qp->s_timer.function = rc_timeout; + /* 4.096 usec. * (1 << qp->timeout) */ + qp->s_timer.expires = jiffies + + usecs_to_jiffies((4096UL * (1UL << qp->timeout)) / 1000UL); + add_timer(&qp->s_timer); +} + +/** + * qib_make_rc_ack - construct a response packet (ACK, NAK, or RDMA read) + * @dev: the device for this QP + * @qp: a pointer to the QP + * @ohdr: a pointer to the IB header being constructed + * @pmtu: the path MTU + * + * Return 1 if constructed; otherwise, return 0. + * Note that we are in the responder's side of the QP context. + * Note the QP s_lock must be held. + */ +static int qib_make_rc_ack(struct qib_ibdev *dev, struct qib_qp *qp, + struct qib_other_headers *ohdr, u32 pmtu) +{ + struct qib_ack_entry *e; + u32 hwords; + u32 len; + u32 bth0; + u32 bth2; + + /* Don't send an ACK if we aren't supposed to. */ + if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) + goto bail; + + /* header size in 32-bit words LRH+BTH = (8+12)/4. */ + hwords = 5; + + switch (qp->s_ack_state) { + case OP(RDMA_READ_RESPONSE_LAST): + case OP(RDMA_READ_RESPONSE_ONLY): + e = &qp->s_ack_queue[qp->s_tail_ack_queue]; + if (e->rdma_sge.mr) { + atomic_dec(&e->rdma_sge.mr->refcount); + e->rdma_sge.mr = NULL; + } + /* FALLTHROUGH */ + case OP(ATOMIC_ACKNOWLEDGE): + /* + * We can increment the tail pointer now that the last + * response has been sent instead of only being + * constructed. + */ + if (++qp->s_tail_ack_queue > QIB_MAX_RDMA_ATOMIC) + qp->s_tail_ack_queue = 0; + /* FALLTHROUGH */ + case OP(SEND_ONLY): + case OP(ACKNOWLEDGE): + /* Check for no next entry in the queue. */ + if (qp->r_head_ack_queue == qp->s_tail_ack_queue) { + if (qp->s_flags & QIB_S_ACK_PENDING) + goto normal; + goto bail; + } + + e = &qp->s_ack_queue[qp->s_tail_ack_queue]; + if (e->opcode == OP(RDMA_READ_REQUEST)) { + /* + * If a RDMA read response is being resent and + * we haven't seen the duplicate request yet, + * then stop sending the remaining responses the + * responder has seen until the requester resends it. + */ + len = e->rdma_sge.sge_length; + if (len && !e->rdma_sge.mr) { + qp->s_tail_ack_queue = qp->r_head_ack_queue; + goto bail; + } + /* Copy SGE state in case we need to resend */ + qp->s_rdma_mr = e->rdma_sge.mr; + if (qp->s_rdma_mr) + atomic_inc(&qp->s_rdma_mr->refcount); + qp->s_ack_rdma_sge.sge = e->rdma_sge; + qp->s_ack_rdma_sge.num_sge = 1; + qp->s_cur_sge = &qp->s_ack_rdma_sge; + if (len > pmtu) { + len = pmtu; + qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST); + } else { + qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY); + e->sent = 1; + } + ohdr->u.aeth = qib_compute_aeth(qp); + hwords++; + qp->s_ack_rdma_psn = e->psn; + bth2 = qp->s_ack_rdma_psn++ & QIB_PSN_MASK; + } else { + /* COMPARE_SWAP or FETCH_ADD */ + qp->s_cur_sge = NULL; + len = 0; + qp->s_ack_state = OP(ATOMIC_ACKNOWLEDGE); + ohdr->u.at.aeth = qib_compute_aeth(qp); + ohdr->u.at.atomic_ack_eth[0] = + cpu_to_be32(e->atomic_data >> 32); + ohdr->u.at.atomic_ack_eth[1] = + cpu_to_be32(e->atomic_data); + hwords += sizeof(ohdr->u.at) / sizeof(u32); + bth2 = e->psn & QIB_PSN_MASK; + e->sent = 1; + } + bth0 = qp->s_ack_state << 24; + break; + + case OP(RDMA_READ_RESPONSE_FIRST): + qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE); + /* FALLTHROUGH */ + case OP(RDMA_READ_RESPONSE_MIDDLE): + qp->s_cur_sge = &qp->s_ack_rdma_sge; + qp->s_rdma_mr = qp->s_ack_rdma_sge.sge.mr; + if (qp->s_rdma_mr) + atomic_inc(&qp->s_rdma_mr->refcount); + len = qp->s_ack_rdma_sge.sge.sge_length; + if (len > pmtu) + len = pmtu; + else { + ohdr->u.aeth = qib_compute_aeth(qp); + hwords++; + qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST); + e = &qp->s_ack_queue[qp->s_tail_ack_queue]; + e->sent = 1; + } + bth0 = qp->s_ack_state << 24; + bth2 = qp->s_ack_rdma_psn++ & QIB_PSN_MASK; + break; + + default: +normal: + /* + * Send a regular ACK. + * Set the s_ack_state so we wait until after sending + * the ACK before setting s_ack_state to ACKNOWLEDGE + * (see above). + */ + qp->s_ack_state = OP(SEND_ONLY); + qp->s_flags &= ~QIB_S_ACK_PENDING; + qp->s_cur_sge = NULL; + if (qp->s_nak_state) + ohdr->u.aeth = + cpu_to_be32((qp->r_msn & QIB_MSN_MASK) | + (qp->s_nak_state << + QIB_AETH_CREDIT_SHIFT)); + else + ohdr->u.aeth = qib_compute_aeth(qp); + hwords++; + len = 0; + bth0 = OP(ACKNOWLEDGE) << 24; + bth2 = qp->s_ack_psn & QIB_PSN_MASK; + } + qp->s_rdma_ack_cnt++; + qp->s_hdrwords = hwords; + qp->s_cur_size = len; + qib_make_ruc_header(qp, ohdr, bth0, bth2); + return 1; + +bail: + qp->s_ack_state = OP(ACKNOWLEDGE); + qp->s_flags &= ~(QIB_S_RESP_PENDING | QIB_S_ACK_PENDING); + return 0; +} + +/** + * qib_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC) + * @qp: a pointer to the QP + * + * Return 1 if constructed; otherwise, return 0. + */ +int qib_make_rc_req(struct qib_qp *qp) +{ + struct qib_ibdev *dev = to_idev(qp->ibqp.device); + struct qib_other_headers *ohdr; + struct qib_sge_state *ss; + struct qib_swqe *wqe; + u32 hwords; + u32 len; + u32 bth0; + u32 bth2; + u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu); + char newreq; + unsigned long flags; + int ret = 0; + int delta; + + ohdr = &qp->s_hdr.u.oth; + if (qp->remote_ah_attr.ah_flags & IB_AH_GRH) + ohdr = &qp->s_hdr.u.l.oth; + + /* + * The lock is needed to synchronize between the sending tasklet, + * the receive interrupt handler, and timeout resends. + */ + spin_lock_irqsave(&qp->s_lock, flags); + + /* Sending responses has higher priority over sending requests. */ + if ((qp->s_flags & QIB_S_RESP_PENDING) && + qib_make_rc_ack(dev, qp, ohdr, pmtu)) + goto done; + + if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_SEND_OK)) { + if (!(ib_qib_state_ops[qp->state] & QIB_FLUSH_SEND)) + goto bail; + /* We are in the error state, flush the work request. */ + if (qp->s_last == qp->s_head) + goto bail; + /* If DMAs are in progress, we can't flush immediately. */ + if (atomic_read(&qp->s_dma_busy)) { + qp->s_flags |= QIB_S_WAIT_DMA; + goto bail; + } + wqe = get_swqe_ptr(qp, qp->s_last); + while (qp->s_last != qp->s_acked) { + qib_send_complete(qp, wqe, IB_WC_SUCCESS); + if (++qp->s_last >= qp->s_size) + qp->s_last = 0; + wqe = get_swqe_ptr(qp, qp->s_last); + } + qib_send_complete(qp, wqe, IB_WC_WR_FLUSH_ERR); + goto done; + } + + if (qp->s_flags & (QIB_S_WAIT_RNR | QIB_S_WAIT_ACK)) + goto bail; + + if (qib_cmp24(qp->s_psn, qp->s_sending_hpsn) <= 0) { + if (qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) { + qp->s_flags |= QIB_S_WAIT_PSN; + goto bail; + } + qp->s_sending_psn = qp->s_psn; + qp->s_sending_hpsn = qp->s_psn - 1; + } + + /* header size in 32-bit words LRH+BTH = (8+12)/4. */ + hwords = 5; + bth0 = 0; + + /* Send a request. */ + wqe = get_swqe_ptr(qp, qp->s_cur); + switch (qp->s_state) { + default: + if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_NEXT_SEND_OK)) + goto bail; + /* + * Resend an old request or start a new one. + * + * We keep track of the current SWQE so that + * we don't reset the "furthest progress" state + * if we need to back up. + */ + newreq = 0; + if (qp->s_cur == qp->s_tail) { + /* Check if send work queue is empty. */ + if (qp->s_tail == qp->s_head) + goto bail; + /* + * If a fence is requested, wait for previous + * RDMA read and atomic operations to finish. + */ + if ((wqe->wr.send_flags & IB_SEND_FENCE) && + qp->s_num_rd_atomic) { + qp->s_flags |= QIB_S_WAIT_FENCE; + goto bail; + } + wqe->psn = qp->s_next_psn; + newreq = 1; + } + /* + * Note that we have to be careful not to modify the + * original work request since we may need to resend + * it. + */ + len = wqe->length; + ss = &qp->s_sge; + bth2 = qp->s_psn & QIB_PSN_MASK; + switch (wqe->wr.opcode) { + case IB_WR_SEND: + case IB_WR_SEND_WITH_IMM: + /* If no credit, return. */ + if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT) && + qib_cmp24(wqe->ssn, qp->s_lsn + 1) > 0) { + qp->s_flags |= QIB_S_WAIT_SSN_CREDIT; + goto bail; + } + wqe->lpsn = wqe->psn; + if (len > pmtu) { + wqe->lpsn += (len - 1) / pmtu; + qp->s_state = OP(SEND_FIRST); + len = pmtu; + break; + } + if (wqe->wr.opcode == IB_WR_SEND) + qp->s_state = OP(SEND_ONLY); + else { + qp->s_state = OP(SEND_ONLY_WITH_IMMEDIATE); + /* Immediate data comes after the BTH */ + ohdr->u.imm_data = wqe->wr.ex.imm_data; + hwords += 1; + } + if (wqe->wr.send_flags & IB_SEND_SOLICITED) + bth0 |= IB_BTH_SOLICITED; + bth2 |= IB_BTH_REQ_ACK; + if (++qp->s_cur == qp->s_size) + qp->s_cur = 0; + break; + + case IB_WR_RDMA_WRITE: + if (newreq && !(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) + qp->s_lsn++; + /* FALLTHROUGH */ + case IB_WR_RDMA_WRITE_WITH_IMM: + /* If no credit, return. */ + if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT) && + qib_cmp24(wqe->ssn, qp->s_lsn + 1) > 0) { + qp->s_flags |= QIB_S_WAIT_SSN_CREDIT; + goto bail; + } + ohdr->u.rc.reth.vaddr = + cpu_to_be64(wqe->wr.wr.rdma.remote_addr); + ohdr->u.rc.reth.rkey = + cpu_to_be32(wqe->wr.wr.rdma.rkey); + ohdr->u.rc.reth.length = cpu_to_be32(len); + hwords += sizeof(struct ib_reth) / sizeof(u32); + wqe->lpsn = wqe->psn; + if (len > pmtu) { + wqe->lpsn += (len - 1) / pmtu; + qp->s_state = OP(RDMA_WRITE_FIRST); + len = pmtu; + break; + } + if (wqe->wr.opcode == IB_WR_RDMA_WRITE) + qp->s_state = OP(RDMA_WRITE_ONLY); + else { + qp->s_state = + OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE); + /* Immediate data comes after RETH */ + ohdr->u.rc.imm_data = wqe->wr.ex.imm_data; + hwords += 1; + if (wqe->wr.send_flags & IB_SEND_SOLICITED) + bth0 |= IB_BTH_SOLICITED; + } + bth2 |= IB_BTH_REQ_ACK; + if (++qp->s_cur == qp->s_size) + qp->s_cur = 0; + break; + + case IB_WR_RDMA_READ: + /* + * Don't allow more operations to be started + * than the QP limits allow. + */ + if (newreq) { + if (qp->s_num_rd_atomic >= + qp->s_max_rd_atomic) { + qp->s_flags |= QIB_S_WAIT_RDMAR; + goto bail; + } + qp->s_num_rd_atomic++; + if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) + qp->s_lsn++; + /* + * Adjust s_next_psn to count the + * expected number of responses. + */ + if (len > pmtu) + qp->s_next_psn += (len - 1) / pmtu; + wqe->lpsn = qp->s_next_psn++; + } + ohdr->u.rc.reth.vaddr = + cpu_to_be64(wqe->wr.wr.rdma.remote_addr); + ohdr->u.rc.reth.rkey = + cpu_to_be32(wqe->wr.wr.rdma.rkey); + ohdr->u.rc.reth.length = cpu_to_be32(len); + qp->s_state = OP(RDMA_READ_REQUEST); + hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32); + ss = NULL; + len = 0; + bth2 |= IB_BTH_REQ_ACK; + if (++qp->s_cur == qp->s_size) + qp->s_cur = 0; + break; + + case IB_WR_ATOMIC_CMP_AND_SWP: + case IB_WR_ATOMIC_FETCH_AND_ADD: + /* + * Don't allow more operations to be started + * than the QP limits allow. + */ + if (newreq) { + if (qp->s_num_rd_atomic >= + qp->s_max_rd_atomic) { + qp->s_flags |= QIB_S_WAIT_RDMAR; + goto bail; + } + qp->s_num_rd_atomic++; + if (!(qp->s_flags & QIB_S_UNLIMITED_CREDIT)) + qp->s_lsn++; + wqe->lpsn = wqe->psn; + } + if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP) { + qp->s_state = OP(COMPARE_SWAP); + ohdr->u.atomic_eth.swap_data = cpu_to_be64( + wqe->wr.wr.atomic.swap); + ohdr->u.atomic_eth.compare_data = cpu_to_be64( + wqe->wr.wr.atomic.compare_add); + } else { + qp->s_state = OP(FETCH_ADD); + ohdr->u.atomic_eth.swap_data = cpu_to_be64( + wqe->wr.wr.atomic.compare_add); + ohdr->u.atomic_eth.compare_data = 0; + } + ohdr->u.atomic_eth.vaddr[0] = cpu_to_be32( + wqe->wr.wr.atomic.remote_addr >> 32); + ohdr->u.atomic_eth.vaddr[1] = cpu_to_be32( + wqe->wr.wr.atomic.remote_addr); + ohdr->u.atomic_eth.rkey = cpu_to_be32( + wqe->wr.wr.atomic.rkey); + hwords += sizeof(struct ib_atomic_eth) / sizeof(u32); + ss = NULL; + len = 0; + bth2 |= IB_BTH_REQ_ACK; + if (++qp->s_cur == qp->s_size) + qp->s_cur = 0; + break; + + default: + goto bail; + } + qp->s_sge.sge = wqe->sg_list[0]; + qp->s_sge.sg_list = wqe->sg_list + 1; + qp->s_sge.num_sge = wqe->wr.num_sge; + qp->s_sge.total_len = wqe->length; + qp->s_len = wqe->length; + if (newreq) { + qp->s_tail++; + if (qp->s_tail >= qp->s_size) + qp->s_tail = 0; + } + if (wqe->wr.opcode == IB_WR_RDMA_READ) + qp->s_psn = wqe->lpsn + 1; + else { + qp->s_psn++; + if (qib_cmp24(qp->s_psn, qp->s_next_psn) > 0) + qp->s_next_psn = qp->s_psn; + } + break; + + case OP(RDMA_READ_RESPONSE_FIRST): + /* + * qp->s_state is normally set to the opcode of the + * last packet constructed for new requests and therefore + * is never set to RDMA read response. + * RDMA_READ_RESPONSE_FIRST is used by the ACK processing + * thread to indicate a SEND needs to be restarted from an + * earlier PSN without interferring with the sending thread. + * See qib_restart_rc(). + */ + qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu); + /* FALLTHROUGH */ + case OP(SEND_FIRST): + qp->s_state = OP(SEND_MIDDLE); + /* FALLTHROUGH */ + case OP(SEND_MIDDLE): + bth2 = qp->s_psn++ & QIB_PSN_MASK; + if (qib_cmp24(qp->s_psn, qp->s_next_psn) > 0) + qp->s_next_psn = qp->s_psn; + ss = &qp->s_sge; + len = qp->s_len; + if (len > pmtu) { + len = pmtu; + break; + } + if (wqe->wr.opcode == IB_WR_SEND) + qp->s_state = OP(SEND_LAST); + else { + qp->s_state = OP(SEND_LAST_WITH_IMMEDIATE); + /* Immediate data comes after the BTH */ + ohdr->u.imm_data = wqe->wr.ex.imm_data; + hwords += 1; + } + if (wqe->wr.send_flags & IB_SEND_SOLICITED) + bth0 |= IB_BTH_SOLICITED; + bth2 |= IB_BTH_REQ_ACK; + qp->s_cur++; + if (qp->s_cur >= qp->s_size) + qp->s_cur = 0; + break; + + case OP(RDMA_READ_RESPONSE_LAST): + /* + * qp->s_state is normally set to the opcode of the + * last packet constructed for new requests and therefore + * is never set to RDMA read response. + * RDMA_READ_RESPONSE_LAST is used by the ACK processing + * thread to indicate a RDMA write needs to be restarted from + * an earlier PSN without interferring with the sending thread. + * See qib_restart_rc(). + */ + qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn, pmtu); + /* FALLTHROUGH */ + case OP(RDMA_WRITE_FIRST): + qp->s_state = OP(RDMA_WRITE_MIDDLE); + /* FALLTHROUGH */ + case OP(RDMA_WRITE_MIDDLE): + bth2 = qp->s_psn++ & QIB_PSN_MASK; + if (qib_cmp24(qp->s_psn, qp->s_next_psn) > 0) + qp->s_next_psn = qp->s_psn; + ss = &qp->s_sge; + len = qp->s_len; + if (len > pmtu) { + len = pmtu; + break; + } + if (wqe->wr.opcode == IB_WR_RDMA_WRITE) + qp->s_state = OP(RDMA_WRITE_LAST); + else { + qp->s_state = OP(RDMA_WRITE_LAST_WITH_IMMEDIATE); + /* Immediate data comes after the BTH */ + ohdr->u.imm_data = wqe->wr.ex.imm_data; + hwords += 1; + if (wqe->wr.send_flags & IB_SEND_SOLICITED) + bth0 |= IB_BTH_SOLICITED; + } + bth2 |= IB_BTH_REQ_ACK; + qp->s_cur++; + if (qp->s_cur >= qp->s_size) + qp->s_cur = 0; + break; + + case OP(RDMA_READ_RESPONSE_MIDDLE): + /* + * qp->s_state is normally set to the opcode of the + * last packet constructed for new requests and therefore + * is never set to RDMA read response. + * RDMA_READ_RESPONSE_MIDDLE is used by the ACK processing + * thread to indicate a RDMA read needs to be restarted from + * an earlier PSN without interferring with the sending thread. + * See qib_restart_rc(). + */ + len = ((qp->s_psn - wqe->psn) & QIB_PSN_MASK) * pmtu; + ohdr->u.rc.reth.vaddr = + cpu_to_be64(wqe->wr.wr.rdma.remote_addr + len); + ohdr->u.rc.reth.rkey = + cpu_to_be32(wqe->wr.wr.rdma.rkey); + ohdr->u.rc.reth.length = cpu_to_be32(wqe->length - len); + qp->s_state = OP(RDMA_READ_REQUEST); + hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32); + bth2 = (qp->s_psn & QIB_PSN_MASK) | IB_BTH_REQ_ACK; + qp->s_psn = wqe->lpsn + 1; + ss = NULL; + len = 0; + qp->s_cur++; + if (qp->s_cur == qp->s_size) + qp->s_cur = 0; + break; + } + qp->s_sending_hpsn = bth2; + delta = (((int) bth2 - (int) wqe->psn) << 8) >> 8; + if (delta && delta % QIB_PSN_CREDIT == 0) + bth2 |= IB_BTH_REQ_ACK; + if (qp->s_flags & QIB_S_SEND_ONE) { + qp->s_flags &= ~QIB_S_SEND_ONE; + qp->s_flags |= QIB_S_WAIT_ACK; + bth2 |= IB_BTH_REQ_ACK; + } + qp->s_len -= len; + qp->s_hdrwords = hwords; + qp->s_cur_sge = ss; + qp->s_cur_size = len; + qib_make_ruc_header(qp, ohdr, bth0 | (qp->s_state << 24), bth2); +done: + ret = 1; + goto unlock; + +bail: + qp->s_flags &= ~QIB_S_BUSY; +unlock: + spin_unlock_irqrestore(&qp->s_lock, flags); + return ret; +} + +/** + * qib_send_rc_ack - Construct an ACK packet and send it + * @qp: a pointer to the QP + * + * This is called from qib_rc_rcv() and qib_kreceive(). + * Note that RDMA reads and atomics are handled in the + * send side QP state and tasklet. + */ +void qib_send_rc_ack(struct qib_qp *qp) +{ + struct qib_devdata *dd = dd_from_ibdev(qp->ibqp.device); + struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num); + struct qib_pportdata *ppd = ppd_from_ibp(ibp); + u64 pbc; + u16 lrh0; + u32 bth0; + u32 hwords; + u32 pbufn; + u32 __iomem *piobuf; + struct qib_ib_header hdr; + struct qib_other_headers *ohdr; + u32 control; + unsigned long flags; + + spin_lock_irqsave(&qp->s_lock, flags); + + if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) + goto unlock; + + /* Don't send ACK or NAK if a RDMA read or atomic is pending. */ + if ((qp->s_flags & QIB_S_RESP_PENDING) || qp->s_rdma_ack_cnt) + goto queue_ack; + + /* Construct the header with s_lock held so APM doesn't change it. */ + ohdr = &hdr.u.oth; + lrh0 = QIB_LRH_BTH; + /* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4. */ + hwords = 6; + if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) { + hwords += qib_make_grh(ibp, &hdr.u.l.grh, + &qp->remote_ah_attr.grh, hwords, 0); + ohdr = &hdr.u.l.oth; + lrh0 = QIB_LRH_GRH; + } + /* read pkey_index w/o lock (its atomic) */ + bth0 = qib_get_pkey(ibp, qp->s_pkey_index) | (OP(ACKNOWLEDGE) << 24); + if (qp->s_mig_state == IB_MIG_MIGRATED) + bth0 |= IB_BTH_MIG_REQ; + if (qp->r_nak_state) + ohdr->u.aeth = cpu_to_be32((qp->r_msn & QIB_MSN_MASK) | + (qp->r_nak_state << + QIB_AETH_CREDIT_SHIFT)); + else + ohdr->u.aeth = qib_compute_aeth(qp); + lrh0 |= ibp->sl_to_vl[qp->remote_ah_attr.sl] << 12 | + qp->remote_ah_attr.sl << 4; + hdr.lrh[0] = cpu_to_be16(lrh0); + hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid); + hdr.lrh[2] = cpu_to_be16(hwords + SIZE_OF_CRC); + hdr.lrh[3] = cpu_to_be16(ppd->lid | qp->remote_ah_attr.src_path_bits); + ohdr->bth[0] = cpu_to_be32(bth0); + ohdr->bth[1] = cpu_to_be32(qp->remote_qpn); + ohdr->bth[2] = cpu_to_be32(qp->r_ack_psn & QIB_PSN_MASK); + + spin_unlock_irqrestore(&qp->s_lock, flags); + + /* Don't try to send ACKs if the link isn't ACTIVE */ + if (!(ppd->lflags & QIBL_LINKACTIVE)) + goto done; + + control = dd->f_setpbc_control(ppd, hwords + SIZE_OF_CRC, + qp->s_srate, lrh0 >> 12); + /* length is + 1 for the control dword */ + pbc = ((u64) control << 32) | (hwords + 1); + + piobuf = dd->f_getsendbuf(ppd, pbc, &pbufn); + if (!piobuf) { + /* + * We are out of PIO buffers at the moment. + * Pass responsibility for sending the ACK to the + * send tasklet so that when a PIO buffer becomes + * available, the ACK is sent ahead of other outgoing + * packets. + */ + spin_lock_irqsave(&qp->s_lock, flags); + goto queue_ack; + } + + /* + * Write the pbc. + * We have to flush after the PBC for correctness + * on some cpus or WC buffer can be written out of order. + */ + writeq(pbc, piobuf); + + if (dd->flags & QIB_PIO_FLUSH_WC) { + u32 *hdrp = (u32 *) &hdr; + + qib_flush_wc(); + qib_pio_copy(piobuf + 2, hdrp, hwords - 1); + qib_flush_wc(); + __raw_writel(hdrp[hwords - 1], piobuf + hwords + 1); + } else + qib_pio_copy(piobuf + 2, (u32 *) &hdr, hwords); + + if (dd->flags & QIB_USE_SPCL_TRIG) { + u32 spcl_off = (pbufn >= dd->piobcnt2k) ? 2047 : 1023; + + qib_flush_wc(); + __raw_writel(0xaebecede, piobuf + spcl_off); + } + + qib_flush_wc(); + qib_sendbuf_done(dd, pbufn); + + ibp->n_unicast_xmit++; + goto done; + +queue_ack: + if (ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK) { + ibp->n_rc_qacks++; + qp->s_flags |= QIB_S_ACK_PENDING | QIB_S_RESP_PENDING; + qp->s_nak_state = qp->r_nak_state; + qp->s_ack_psn = qp->r_ack_psn; + + /* Schedule the send tasklet. */ + qib_schedule_send(qp); + } +unlock: + spin_unlock_irqrestore(&qp->s_lock, flags); +done: + return; +} + +/** + * reset_psn - reset the QP state to send starting from PSN + * @qp: the QP + * @psn: the packet sequence number to restart at + * + * This is called from qib_rc_rcv() to process an incoming RC ACK + * for the given QP. + * Called at interrupt level with the QP s_lock held. + */ +static void reset_psn(struct qib_qp *qp, u32 psn) +{ + u32 n = qp->s_acked; + struct qib_swqe *wqe = get_swqe_ptr(qp, n); + u32 opcode; + + qp->s_cur = n; + + /* + * If we are starting the request from the beginning, + * let the normal send code handle initialization. + */ + if (qib_cmp24(psn, wqe->psn) <= 0) { + qp->s_state = OP(SEND_LAST); + goto done; + } + + /* Find the work request opcode corresponding to the given PSN. */ + opcode = wqe->wr.opcode; + for (;;) { + int diff; + + if (++n == qp->s_size) + n = 0; + if (n == qp->s_tail) + break; + wqe = get_swqe_ptr(qp, n); + diff = qib_cmp24(psn, wqe->psn); + if (diff < 0) + break; + qp->s_cur = n; + /* + * If we are starting the request from the beginning, + * let the normal send code handle initialization. + */ + if (diff == 0) { + qp->s_state = OP(SEND_LAST); + goto done; + } + opcode = wqe->wr.opcode; + } + + /* + * Set the state to restart in the middle of a request. + * Don't change the s_sge, s_cur_sge, or s_cur_size. + * See qib_make_rc_req(). + */ + switch (opcode) { + case IB_WR_SEND: + case IB_WR_SEND_WITH_IMM: + qp->s_state = OP(RDMA_READ_RESPONSE_FIRST); + break; + + case IB_WR_RDMA_WRITE: + case IB_WR_RDMA_WRITE_WITH_IMM: + qp->s_state = OP(RDMA_READ_RESPONSE_LAST); + break; + + case IB_WR_RDMA_READ: + qp->s_state = OP(RDMA_READ_RESPONSE_MIDDLE); + break; + + default: + /* + * This case shouldn't happen since its only + * one PSN per req. + */ + qp->s_state = OP(SEND_LAST); + } +done: + qp->s_psn = psn; + /* + * Set QIB_S_WAIT_PSN as qib_rc_complete() may start the timer + * asynchronously before the send tasklet can get scheduled. + * Doing it in qib_make_rc_req() is too late. + */ + if ((qib_cmp24(qp->s_psn, qp->s_sending_hpsn) <= 0) && + (qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)) + qp->s_flags |= QIB_S_WAIT_PSN; +} + +/* + * Back up requester to resend the last un-ACKed request. + * The QP s_lock should be held and interrupts disabled. + */ +static void qib_restart_rc(struct qib_qp *qp, u32 psn, int wait) +{ + struct qib_swqe *wqe = get_swqe_ptr(qp, qp->s_acked); + struct qib_ibport *ibp; + + if (qp->s_retry == 0) { + if (qp->s_mig_state == IB_MIG_ARMED) { + qib_migrate_qp(qp); + qp->s_retry = qp->s_retry_cnt; + } else if (qp->s_last == qp->s_acked) { + qib_send_complete(qp, wqe, IB_WC_RETRY_EXC_ERR); + qib_error_qp(qp, IB_WC_WR_FLUSH_ERR); + return; + } else /* XXX need to handle delayed completion */ + return; + } else + qp->s_retry--; + + ibp = to_iport(qp->ibqp.device, qp->port_num); + if (wqe->wr.opcode == IB_WR_RDMA_READ) + ibp->n_rc_resends++; + else + ibp->n_rc_resends += (qp->s_psn - psn) & QIB_PSN_MASK; + + qp->s_flags &= ~(QIB_S_WAIT_FENCE | QIB_S_WAIT_RDMAR | + QIB_S_WAIT_SSN_CREDIT | QIB_S_WAIT_PSN | + QIB_S_WAIT_ACK); + if (wait) + qp->s_flags |= QIB_S_SEND_ONE; + reset_psn(qp, psn); +} + +/* + * This is called from s_timer for missing responses. + */ +static void rc_timeout(unsigned long arg) +{ + struct qib_qp *qp = (struct qib_qp *)arg; + struct qib_ibport *ibp; + unsigned long flags; + + spin_lock_irqsave(&qp->s_lock, flags); + if (qp->s_flags & QIB_S_TIMER) { + ibp = to_iport(qp->ibqp.device, qp->port_num); + ibp->n_rc_timeouts++; + qp->s_flags &= ~QIB_S_TIMER; + del_timer(&qp->s_timer); + qib_restart_rc(qp, qp->s_last_psn + 1, 1); + qib_schedule_send(qp); + } + spin_unlock_irqrestore(&qp->s_lock, flags); +} + +/* + * This is called from s_timer for RNR timeouts. + */ +void qib_rc_rnr_retry(unsigned long arg) +{ + struct qib_qp *qp = (struct qib_qp *)arg; + unsigned long flags; + + spin_lock_irqsave(&qp->s_lock, flags); + if (qp->s_flags & QIB_S_WAIT_RNR) { + qp->s_flags &= ~QIB_S_WAIT_RNR; + del_timer(&qp->s_timer); + qib_schedule_send(qp); + } + spin_unlock_irqrestore(&qp->s_lock, flags); +} + +/* + * Set qp->s_sending_psn to the next PSN after the given one. + * This would be psn+1 except when RDMA reads are present. + */ +static void reset_sending_psn(struct qib_qp *qp, u32 psn) +{ + struct qib_swqe *wqe; + u32 n = qp->s_last; + + /* Find the work request corresponding to the given PSN. */ + for (;;) { + wqe = get_swqe_ptr(qp, n); + if (qib_cmp24(psn, wqe->lpsn) <= 0) { + if (wqe->wr.opcode == IB_WR_RDMA_READ) + qp->s_sending_psn = wqe->lpsn + 1; + else + qp->s_sending_psn = psn + 1; + break; + } + if (++n == qp->s_size) + n = 0; + if (n == qp->s_tail) + break; + } +} + +/* + * This should be called with the QP s_lock held and interrupts disabled. + */ +void qib_rc_send_complete(struct qib_qp *qp, struct qib_ib_header *hdr) +{ + struct qib_other_headers *ohdr; + struct qib_swqe *wqe; + struct ib_wc wc; + unsigned i; + u32 opcode; + u32 psn; + + if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_OR_FLUSH_SEND)) + return; + + /* Find out where the BTH is */ + if ((be16_to_cpu(hdr->lrh[0]) & 3) == QIB_LRH_BTH) + ohdr = &hdr->u.oth; + else + ohdr = &hdr->u.l.oth; + + opcode = be32_to_cpu(ohdr->bth[0]) >> 24; + if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) && + opcode <= OP(ATOMIC_ACKNOWLEDGE)) { + WARN_ON(!qp->s_rdma_ack_cnt); + qp->s_rdma_ack_cnt--; + return; + } + + psn = be32_to_cpu(ohdr->bth[2]); + reset_sending_psn(qp, psn); + + /* + * Start timer after a packet requesting an ACK has been sent and + * there are still requests that haven't been acked. + */ + if ((psn & IB_BTH_REQ_ACK) && qp->s_acked != qp->s_tail && + !(qp->s_flags & (QIB_S_TIMER | QIB_S_WAIT_RNR | QIB_S_WAIT_PSN))) + start_timer(qp); + + while (qp->s_last != qp->s_acked) { + wqe = get_swqe_ptr(qp, qp->s_last); + if (qib_cmp24(wqe->lpsn, qp->s_sending_psn) >= 0 && + qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) <= 0) + break; + for (i = 0; i < wqe->wr.num_sge; i++) { + struct qib_sge *sge = &wqe->sg_list[i]; + + atomic_dec(&sge->mr->refcount); + } + /* Post a send completion queue entry if requested. */ + if (!(qp->s_flags & QIB_S_SIGNAL_REQ_WR) || + (wqe->wr.send_flags & IB_SEND_SIGNALED)) { + memset(&wc, 0, sizeof wc); + wc.wr_id = wqe->wr.wr_id; + wc.status = IB_WC_SUCCESS; + wc.opcode = ib_qib_wc_opcode[wqe->wr.opcode]; + wc.byte_len = wqe->length; + wc.qp = &qp->ibqp; + qib_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 0); + } + if (++qp->s_last >= qp->s_size) + qp->s_last = 0; + } + /* + * If we were waiting for sends to complete before resending, + * and they are now complete, restart sending. + */ + if (qp->s_flags & QIB_S_WAIT_PSN && + qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) > 0) { + qp->s_flags &= ~QIB_S_WAIT_PSN; + qp->s_sending_psn = qp->s_psn; + qp->s_sending_hpsn = qp->s_psn - 1; + qib_schedule_send(qp); + } +} + +static inline void update_last_psn(struct qib_qp *qp, u32 psn) +{ + qp->s_last_psn = psn; +} + +/* + * Generate a SWQE completion. + * This is similar to qib_send_complete but has to check to be sure + * that the SGEs are not being referenced if the SWQE is being resent. + */ +static struct qib_swqe *do_rc_completion(struct qib_qp *qp, + struct qib_swqe *wqe, + struct qib_ibport *ibp) +{ + struct ib_wc wc; + unsigned i; + + /* + * Don't decrement refcount and don't generate a + * completion if the SWQE is being resent until the send + * is finished. + */ + if (qib_cmp24(wqe->lpsn, qp->s_sending_psn) < 0 || + qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) > 0) { + for (i = 0; i < wqe->wr.num_sge; i++) { + struct qib_sge *sge = &wqe->sg_list[i]; + + atomic_dec(&sge->mr->refcount); + } + /* Post a send completion queue entry if requested. */ + if (!(qp->s_flags & QIB_S_SIGNAL_REQ_WR) || + (wqe->wr.send_flags & IB_SEND_SIGNALED)) { + memset(&wc, 0, sizeof wc); + wc.wr_id = wqe->wr.wr_id; + wc.status = IB_WC_SUCCESS; + wc.opcode = ib_qib_wc_opcode[wqe->wr.opcode]; + wc.byte_len = wqe->length; + wc.qp = &qp->ibqp; + qib_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 0); + } + if (++qp->s_last >= qp->s_size) + qp->s_last = 0; + } else + ibp->n_rc_delayed_comp++; + + qp->s_retry = qp->s_retry_cnt; + update_last_psn(qp, wqe->lpsn); + + /* + * If we are completing a request which is in the process of + * being resent, we can stop resending it since we know the + * responder has already seen it. + */ + if (qp->s_acked == qp->s_cur) { + if (++qp->s_cur >= qp->s_size) + qp->s_cur = 0; + qp->s_acked = qp->s_cur; + wqe = get_swqe_ptr(qp, qp->s_cur); + if (qp->s_acked != qp->s_tail) { + qp->s_state = OP(SEND_LAST); + qp->s_psn = wqe->psn; + } + } else { + if (++qp->s_acked >= qp->s_size) + qp->s_acked = 0; + if (qp->state == IB_QPS_SQD && qp->s_acked == qp->s_cur) + qp->s_draining = 0; + wqe = get_swqe_ptr(qp, qp->s_acked); + } + return wqe; +} + +/** + * do_rc_ack - process an incoming RC ACK + * @qp: the QP the ACK came in on + * @psn: the packet sequence number of the ACK + * @opcode: the opcode of the request that resulted in the ACK + * + * This is called from qib_rc_rcv_resp() to process an incoming RC ACK + * for the given QP. + * Called at interrupt level with the QP s_lock held. + * Returns 1 if OK, 0 if current operation should be aborted (NAK). + */ +static int do_rc_ack(struct qib_qp *qp, u32 aeth, u32 psn, int opcode, + u64 val, struct qib_ctxtdata *rcd) +{ + struct qib_ibport *ibp; + enum ib_wc_status status; + struct qib_swqe *wqe; + int ret = 0; + u32 ack_psn; + int diff; + + /* Remove QP from retry timer */ + if (qp->s_flags & (QIB_S_TIMER | QIB_S_WAIT_RNR)) { + qp->s_flags &= ~(QIB_S_TIMER | QIB_S_WAIT_RNR); + del_timer(&qp->s_timer); + } + + /* + * Note that NAKs implicitly ACK outstanding SEND and RDMA write + * requests and implicitly NAK RDMA read and atomic requests issued + * before the NAK'ed request. The MSN won't include the NAK'ed + * request but will include an ACK'ed request(s). + */ + ack_psn = psn; + if (aeth >> 29) + ack_psn--; + wqe = get_swqe_ptr(qp, qp->s_acked); + ibp = to_iport(qp->ibqp.device, qp->port_num); + + /* + * The MSN might be for a later WQE than the PSN indicates so + * only complete WQEs that the PSN finishes. + */ + while ((diff = qib_cmp24(ack_psn, wqe->lpsn)) >= 0) { + /* + * RDMA_READ_RESPONSE_ONLY is a special case since + * we want to generate completion events for everything + * before the RDMA read, copy the data, then generate + * the completion for the read. + */ + if (wqe->wr.opcode == IB_WR_RDMA_READ && + opcode == OP(RDMA_READ_RESPONSE_ONLY) && + diff == 0) { + ret = 1; + goto bail; + } + /* + * If this request is a RDMA read or atomic, and the ACK is + * for a later operation, this ACK NAKs the RDMA read or + * atomic. In other words, only a RDMA_READ_LAST or ONLY + * can ACK a RDMA read and likewise for atomic ops. Note + * that the NAK case can only happen if relaxed ordering is + * used and requests are sent after an RDMA read or atomic + * is sent but before the response is received. + */ + if ((wqe->wr.opcode == IB_WR_RDMA_READ && + (opcode != OP(RDMA_READ_RESPONSE_LAST) || diff != 0)) || + ((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP || + wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) && + (opcode != OP(ATOMIC_ACKNOWLEDGE) || diff != 0))) { + /* Retry this request. */ + if (!(qp->r_flags & QIB_R_RDMAR_SEQ)) { + qp->r_flags |= QIB_R_RDMAR_SEQ; + qib_restart_rc(qp, qp->s_last_psn + 1, 0); + if (list_empty(&qp->rspwait)) { + qp->r_flags |= QIB_R_RSP_SEND; + atomic_inc(&qp->refcount); + list_add_tail(&qp->rspwait, + &rcd->qp_wait_list); + } + } + /* + * No need to process the ACK/NAK since we are + * restarting an earlier request. + */ + goto bail; + } + if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP || + wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) { + u64 *vaddr = wqe->sg_list[0].vaddr; + *vaddr = val; + } + if (qp->s_num_rd_atomic && + (wqe->wr.opcode == IB_WR_RDMA_READ || + wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP || + wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)) { + qp->s_num_rd_atomic--; + /* Restart sending task if fence is complete */ + if ((qp->s_flags & QIB_S_WAIT_FENCE) && + !qp->s_num_rd_atomic) { + qp->s_flags &= ~(QIB_S_WAIT_FENCE | + QIB_S_WAIT_ACK); + qib_schedule_send(qp); + } else if (qp->s_flags & QIB_S_WAIT_RDMAR) { + qp->s_flags &= ~(QIB_S_WAIT_RDMAR | + QIB_S_WAIT_ACK); + qib_schedule_send(qp); + } + } + wqe = do_rc_completion(qp, wqe, ibp); + if (qp->s_acked == qp->s_tail) + break; + } + + switch (aeth >> 29) { + case 0: /* ACK */ + ibp->n_rc_acks++; + if (qp->s_acked != qp->s_tail) { + /* + * We are expecting more ACKs so + * reset the retransmit timer. + */ + start_timer(qp); + /* + * We can stop resending the earlier packets and + * continue with the next packet the receiver wants. + */ + if (qib_cmp24(qp->s_psn, psn) <= 0) + reset_psn(qp, psn + 1); + } else if (qib_cmp24(qp->s_psn, psn) <= 0) { + qp->s_state = OP(SEND_LAST); + qp->s_psn = psn + 1; + } + if (qp->s_flags & QIB_S_WAIT_ACK) { + qp->s_flags &= ~QIB_S_WAIT_ACK; + qib_schedule_send(qp); + } + qib_get_credit(qp, aeth); + qp->s_rnr_retry = qp->s_rnr_retry_cnt; + qp->s_retry = qp->s_retry_cnt; + update_last_psn(qp, psn); + ret = 1; + goto bail; + + case 1: /* RNR NAK */ + ibp->n_rnr_naks++; + if (qp->s_acked == qp->s_tail) + goto bail; + if (qp->s_flags & QIB_S_WAIT_RNR) + goto bail; + if (qp->s_rnr_retry == 0) { + status = IB_WC_RNR_RETRY_EXC_ERR; + goto class_b; + } + if (qp->s_rnr_retry_cnt < 7) + qp->s_rnr_retry--; + + /* The last valid PSN is the previous PSN. */ + update_last_psn(qp, psn - 1); + + ibp->n_rc_resends += (qp->s_psn - psn) & QIB_PSN_MASK; + + reset_psn(qp, psn); + + qp->s_flags &= ~(QIB_S_WAIT_SSN_CREDIT | QIB_S_WAIT_ACK); + qp->s_flags |= QIB_S_WAIT_RNR; + qp->s_timer.function = qib_rc_rnr_retry; + qp->s_timer.expires = jiffies + usecs_to_jiffies( + ib_qib_rnr_table[(aeth >> QIB_AETH_CREDIT_SHIFT) & + QIB_AETH_CREDIT_MASK]); + add_timer(&qp->s_timer); + goto bail; + + case 3: /* NAK */ + if (qp->s_acked == qp->s_tail) + goto bail; + /* The last valid PSN is the previous PSN. */ + update_last_psn(qp, psn - 1); + switch ((aeth >> QIB_AETH_CREDIT_SHIFT) & + QIB_AETH_CREDIT_MASK) { + case 0: /* PSN sequence error */ + ibp->n_seq_naks++; + /* + * Back up to the responder's expected PSN. + * Note that we might get a NAK in the middle of an + * RDMA READ response which terminates the RDMA + * READ. + */ + qib_restart_rc(qp, psn, 0); + qib_schedule_send(qp); + break; + + case 1: /* Invalid Request */ + status = IB_WC_REM_INV_REQ_ERR; + ibp->n_other_naks++; + goto class_b; + + case 2: /* Remote Access Error */ + status = IB_WC_REM_ACCESS_ERR; + ibp->n_other_naks++; + goto class_b; + + case 3: /* Remote Operation Error */ + status = IB_WC_REM_OP_ERR; + ibp->n_other_naks++; +class_b: + if (qp->s_last == qp->s_acked) { + qib_send_complete(qp, wqe, status); + qib_error_qp(qp, IB_WC_WR_FLUSH_ERR); + } + break; + + default: + /* Ignore other reserved NAK error codes */ + goto reserved; + } + qp->s_retry = qp->s_retry_cnt; + qp->s_rnr_retry = qp->s_rnr_retry_cnt; + goto bail; + + default: /* 2: reserved */ +reserved: + /* Ignore reserved NAK codes. */ + goto bail; + } + +bail: + return ret; +} + +/* + * We have seen an out of sequence RDMA read middle or last packet. + * This ACKs SENDs and RDMA writes up to the first RDMA read or atomic SWQE. + */ +static void rdma_seq_err(struct qib_qp *qp, struct qib_ibport *ibp, u32 psn, + struct qib_ctxtdata *rcd) +{ + struct qib_swqe *wqe; + + /* Remove QP from retry timer */ + if (qp->s_flags & (QIB_S_TIMER | QIB_S_WAIT_RNR)) { + qp->s_flags &= ~(QIB_S_TIMER | QIB_S_WAIT_RNR); + del_timer(&qp->s_timer); + } + + wqe = get_swqe_ptr(qp, qp->s_acked); + + while (qib_cmp24(psn, wqe->lpsn) > 0) { + if (wqe->wr.opcode == IB_WR_RDMA_READ || + wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP || + wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) + break; + wqe = do_rc_completion(qp, wqe, ibp); + } + + ibp->n_rdma_seq++; + qp->r_flags |= QIB_R_RDMAR_SEQ; + qib_restart_rc(qp, qp->s_last_psn + 1, 0); + if (list_empty(&qp->rspwait)) { + qp->r_flags |= QIB_R_RSP_SEND; + atomic_inc(&qp->refcount); + list_add_tail(&qp->rspwait, &rcd->qp_wait_list); + } +} + +/** + * qib_rc_rcv_resp - process an incoming RC response packet + * @ibp: the port this packet came in on + * @ohdr: the other headers for this packet + * @data: the packet data + * @tlen: the packet length + * @qp: the QP for this packet + * @opcode: the opcode for this packet + * @psn: the packet sequence number for this packet + * @hdrsize: the header length + * @pmtu: the path MTU + * + * This is called from qib_rc_rcv() to process an incoming RC response + * packet for the given QP. + * Called at interrupt level. + */ +static void qib_rc_rcv_resp(struct qib_ibport *ibp, + struct qib_other_headers *ohdr, + void *data, u32 tlen, + struct qib_qp *qp, + u32 opcode, + u32 psn, u32 hdrsize, u32 pmtu, + struct qib_ctxtdata *rcd) +{ + struct qib_swqe *wqe; + enum ib_wc_status status; + unsigned long flags; + int diff; + u32 pad; + u32 aeth; + u64 val; + + spin_lock_irqsave(&qp->s_lock, flags); + + /* Double check we can process this now that we hold the s_lock. */ + if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) + goto ack_done; + + /* Ignore invalid responses. */ + if (qib_cmp24(psn, qp->s_next_psn) >= 0) + goto ack_done; + + /* Ignore duplicate responses. */ + diff = qib_cmp24(psn, qp->s_last_psn); + if (unlikely(diff <= 0)) { + /* Update credits for "ghost" ACKs */ + if (diff == 0 && opcode == OP(ACKNOWLEDGE)) { + aeth = be32_to_cpu(ohdr->u.aeth); + if ((aeth >> 29) == 0) + qib_get_credit(qp, aeth); + } + goto ack_done; + } + + /* + * Skip everything other than the PSN we expect, if we are waiting + * for a reply to a restarted RDMA read or atomic op. + */ + if (qp->r_flags & QIB_R_RDMAR_SEQ) { + if (qib_cmp24(psn, qp->s_last_psn + 1) != 0) + goto ack_done; + qp->r_flags &= ~QIB_R_RDMAR_SEQ; + } + + if (unlikely(qp->s_acked == qp->s_tail)) + goto ack_done; + wqe = get_swqe_ptr(qp, qp->s_acked); + status = IB_WC_SUCCESS; + + switch (opcode) { + case OP(ACKNOWLEDGE): + case OP(ATOMIC_ACKNOWLEDGE): + case OP(RDMA_READ_RESPONSE_FIRST): + aeth = be32_to_cpu(ohdr->u.aeth); + if (opcode == OP(ATOMIC_ACKNOWLEDGE)) { + __be32 *p = ohdr->u.at.atomic_ack_eth; + + val = ((u64) be32_to_cpu(p[0]) << 32) | + be32_to_cpu(p[1]); + } else + val = 0; + if (!do_rc_ack(qp, aeth, psn, opcode, val, rcd) || + opcode != OP(RDMA_READ_RESPONSE_FIRST)) + goto ack_done; + hdrsize += 4; + wqe = get_swqe_ptr(qp, qp->s_acked); + if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ)) + goto ack_op_err; + /* + * If this is a response to a resent RDMA read, we + * have to be careful to copy the data to the right + * location. + */ + qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge, + wqe, psn, pmtu); + goto read_middle; + + case OP(RDMA_READ_RESPONSE_MIDDLE): + /* no AETH, no ACK */ + if (unlikely(qib_cmp24(psn, qp->s_last_psn + 1))) + goto ack_seq_err; + if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ)) + goto ack_op_err; +read_middle: + if (unlikely(tlen != (hdrsize + pmtu + 4))) + goto ack_len_err; + if (unlikely(pmtu >= qp->s_rdma_read_len)) + goto ack_len_err; + + /* + * We got a response so update the timeout. + * 4.096 usec. * (1 << qp->timeout) + */ + qp->s_flags |= QIB_S_TIMER; + mod_timer(&qp->s_timer, jiffies + + usecs_to_jiffies((4096UL * (1UL << qp->timeout)) / + 1000UL)); + if (qp->s_flags & QIB_S_WAIT_ACK) { + qp->s_flags &= ~QIB_S_WAIT_ACK; + qib_schedule_send(qp); + } + + if (opcode == OP(RDMA_READ_RESPONSE_MIDDLE)) + qp->s_retry = qp->s_retry_cnt; + + /* + * Update the RDMA receive state but do the copy w/o + * holding the locks and blocking interrupts. + */ + qp->s_rdma_read_len -= pmtu; + update_last_psn(qp, psn); + spin_unlock_irqrestore(&qp->s_lock, flags); + qib_copy_sge(&qp->s_rdma_read_sge, data, pmtu, 0); + goto bail; + + case OP(RDMA_READ_RESPONSE_ONLY): + aeth = be32_to_cpu(ohdr->u.aeth); + if (!do_rc_ack(qp, aeth, psn, opcode, 0, rcd)) + goto ack_done; + /* Get the number of bytes the message was padded by. */ + pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3; + /* + * Check that the data size is >= 0 && <= pmtu. + * Remember to account for the AETH header (4) and + * ICRC (4). + */ + if (unlikely(tlen < (hdrsize + pad + 8))) + goto ack_len_err; + /* + * If this is a response to a resent RDMA read, we + * have to be careful to copy the data to the right + * location. + */ + wqe = get_swqe_ptr(qp, qp->s_acked); + qp->s_rdma_read_len = restart_sge(&qp->s_rdma_read_sge, + wqe, psn, pmtu); + goto read_last; + + case OP(RDMA_READ_RESPONSE_LAST): + /* ACKs READ req. */ + if (unlikely(qib_cmp24(psn, qp->s_last_psn + 1))) + goto ack_seq_err; + if (unlikely(wqe->wr.opcode != IB_WR_RDMA_READ)) + goto ack_op_err; + /* Get the number of bytes the message was padded by. */ + pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3; + /* + * Check that the data size is >= 1 && <= pmtu. + * Remember to account for the AETH header (4) and + * ICRC (4). + */ + if (unlikely(tlen <= (hdrsize + pad + 8))) + goto ack_len_err; +read_last: + tlen -= hdrsize + pad + 8; + if (unlikely(tlen != qp->s_rdma_read_len)) + goto ack_len_err; + aeth = be32_to_cpu(ohdr->u.aeth); + qib_copy_sge(&qp->s_rdma_read_sge, data, tlen, 0); + WARN_ON(qp->s_rdma_read_sge.num_sge); + (void) do_rc_ack(qp, aeth, psn, + OP(RDMA_READ_RESPONSE_LAST), 0, rcd); + goto ack_done; + } + +ack_op_err: + status = IB_WC_LOC_QP_OP_ERR; + goto ack_err; + +ack_seq_err: + rdma_seq_err(qp, ibp, psn, rcd); + goto ack_done; + +ack_len_err: + status = IB_WC_LOC_LEN_ERR; +ack_err: + if (qp->s_last == qp->s_acked) { + qib_send_complete(qp, wqe, status); + qib_error_qp(qp, IB_WC_WR_FLUSH_ERR); + } +ack_done: + spin_unlock_irqrestore(&qp->s_lock, flags); +bail: + return; +} + +/** + * qib_rc_rcv_error - process an incoming duplicate or error RC packet + * @ohdr: the other headers for this packet + * @data: the packet data + * @qp: the QP for this packet + * @opcode: the opcode for this packet + * @psn: the packet sequence number for this packet + * @diff: the difference between the PSN and the expected PSN + * + * This is called from qib_rc_rcv() to process an unexpected + * incoming RC packet for the given QP. + * Called at interrupt level. + * Return 1 if no more processing is needed; otherwise return 0 to + * schedule a response to be sent. + */ +static int qib_rc_rcv_error(struct qib_other_headers *ohdr, + void *data, + struct qib_qp *qp, + u32 opcode, + u32 psn, + int diff, + struct qib_ctxtdata *rcd) +{ + struct qib_ibport *ibp = to_iport(qp->ibqp.device, qp->port_num); + struct qib_ack_entry *e; + unsigned long flags; + u8 i, prev; + int old_req; + + if (diff > 0) { + /* + * Packet sequence error. + * A NAK will ACK earlier sends and RDMA writes. + * Don't queue the NAK if we already sent one. + */ + if (!qp->r_nak_state) { + ibp->n_rc_seqnak++; + qp->r_nak_state = IB_NAK_PSN_ERROR; + /* Use the expected PSN. */ + qp->r_ack_psn = qp->r_psn; + /* + * Wait to send the sequence NAK until all packets + * in the receive queue have been processed. + * Otherwise, we end up propagating congestion. + */ + if (list_empty(&qp->rspwait)) { + qp->r_flags |= QIB_R_RSP_NAK; + atomic_inc(&qp->refcount); + list_add_tail(&qp->rspwait, &rcd->qp_wait_list); + } + } + goto done; + } + + /* + * Handle a duplicate request. Don't re-execute SEND, RDMA + * write or atomic op. Don't NAK errors, just silently drop + * the duplicate request. Note that r_sge, r_len, and + * r_rcv_len may be in use so don't modify them. + * + * We are supposed to ACK the earliest duplicate PSN but we + * can coalesce an outstanding duplicate ACK. We have to + * send the earliest so that RDMA reads can be restarted at + * the requester's expected PSN. + * + * First, find where this duplicate PSN falls within the + * ACKs previously sent. + * old_req is true if there is an older response that is scheduled + * to be sent before sending this one. + */ + e = NULL; + old_req = 1; + ibp->n_rc_dupreq++; + + spin_lock_irqsave(&qp->s_lock, flags); + /* Double check we can process this now that we hold the s_lock. */ + if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) + goto unlock_done; + + for (i = qp->r_head_ack_queue; ; i = prev) { + if (i == qp->s_tail_ack_queue) + old_req = 0; + if (i) + prev = i - 1; + else + prev = QIB_MAX_RDMA_ATOMIC; + if (prev == qp->r_head_ack_queue) { + e = NULL; + break; + } + e = &qp->s_ack_queue[prev]; + if (!e->opcode) { + e = NULL; + break; + } + if (qib_cmp24(psn, e->psn) >= 0) { + if (prev == qp->s_tail_ack_queue && + qib_cmp24(psn, e->lpsn) <= 0) + old_req = 0; + break; + } + } + switch (opcode) { + case OP(RDMA_READ_REQUEST): { + struct ib_reth *reth; + u32 offset; + u32 len; + + /* + * If we didn't find the RDMA read request in the ack queue, + * we can ignore this request. + */ + if (!e || e->opcode != OP(RDMA_READ_REQUEST)) + goto unlock_done; + /* RETH comes after BTH */ + reth = &ohdr->u.rc.reth; + /* + * Address range must be a subset of the original + * request and start on pmtu boundaries. + * We reuse the old ack_queue slot since the requester + * should not back up and request an earlier PSN for the + * same request. + */ + offset = ((psn - e->psn) & QIB_PSN_MASK) * + ib_mtu_enum_to_int(qp->path_mtu); + len = be32_to_cpu(reth->length); + if (unlikely(offset + len != e->rdma_sge.sge_length)) + goto unlock_done; + if (e->rdma_sge.mr) { + atomic_dec(&e->rdma_sge.mr->refcount); + e->rdma_sge.mr = NULL; + } + if (len != 0) { + u32 rkey = be32_to_cpu(reth->rkey); + u64 vaddr = be64_to_cpu(reth->vaddr); + int ok; + + ok = qib_rkey_ok(qp, &e->rdma_sge, len, vaddr, rkey, + IB_ACCESS_REMOTE_READ); + if (unlikely(!ok)) + goto unlock_done; + } else { + e->rdma_sge.vaddr = NULL; + e->rdma_sge.length = 0; + e->rdma_sge.sge_length = 0; + } + e->psn = psn; + if (old_req) + goto unlock_done; + qp->s_tail_ack_queue = prev; + break; + } + + case OP(COMPARE_SWAP): + case OP(FETCH_ADD): { + /* + * If we didn't find the atomic request in the ack queue + * or the send tasklet is already backed up to send an + * earlier entry, we can ignore this request. + */ + if (!e || e->opcode != (u8) opcode || old_req) + goto unlock_done; + qp->s_tail_ack_queue = prev; + break; + } + + default: + /* + * Ignore this operation if it doesn't request an ACK + * or an earlier RDMA read or atomic is going to be resent. + */ + if (!(psn & IB_BTH_REQ_ACK) || old_req) + goto unlock_done; + /* + * Resend the most recent ACK if this request is + * after all the previous RDMA reads and atomics. + */ + if (i == qp->r_head_ack_queue) { + spin_unlock_irqrestore(&qp->s_lock, flags); + qp->r_nak_state = 0; + qp->r_ack_psn = qp->r_psn - 1; + goto send_ack; + } + /* + * Try to send a simple ACK to work around a Mellanox bug + * which doesn't accept a RDMA read response or atomic + * response as an ACK for earlier SENDs or RDMA writes. + */ + if (!(qp->s_flags & QIB_S_RESP_PENDING)) { + spin_unlock_irqrestore(&qp->s_lock, flags); + qp->r_nak_state = 0; + qp->r_ack_psn = qp->s_ack_queue[i].psn - 1; + goto send_ack; + } + /* + * Resend the RDMA read or atomic op which + * ACKs this duplicate request. + */ + qp->s_tail_ack_queue = i; + break; + } + qp->s_ack_state = OP(ACKNOWLEDGE); + qp->s_flags |= QIB_S_RESP_PENDING; + qp->r_nak_state = 0; + qib_schedule_send(qp); + +unlock_done: + spin_unlock_irqrestore(&qp->s_lock, flags); +done: + return 1; + +send_ack: + return 0; +} + +void qib_rc_error(struct qib_qp *qp, enum ib_wc_status err) +{ + unsigned long flags; + int lastwqe; + + spin_lock_irqsave(&qp->s_lock, flags); + lastwqe = qib_error_qp(qp, err); + spin_unlock_irqrestore(&qp->s_lock, flags); + + if (lastwqe) { + struct ib_event ev; + + ev.device = qp->ibqp.device; + ev.element.qp = &qp->ibqp; + ev.event = IB_EVENT_QP_LAST_WQE_REACHED; + qp->ibqp.event_handler(&ev, qp->ibqp.qp_context); + } +} + +static inline void qib_update_ack_queue(struct qib_qp *qp, unsigned n) +{ + unsigned next; + + next = n + 1; + if (next > QIB_MAX_RDMA_ATOMIC) + next = 0; + qp->s_tail_ack_queue = next; + qp->s_ack_state = OP(ACKNOWLEDGE); +} + +/** + * qib_rc_rcv - process an incoming RC packet + * @rcd: the context pointer + * @hdr: the header of this packet + * @has_grh: true if the header has a GRH + * @data: the packet data + * @tlen: the packet length + * @qp: the QP for this packet + * + * This is called from qib_qp_rcv() to process an incoming RC packet + * for the given QP. + * Called at interrupt level. + */ +void qib_rc_rcv(struct qib_ctxtdata *rcd, struct qib_ib_header *hdr, + int has_grh, void *data, u32 tlen, struct qib_qp *qp) +{ + struct qib_ibport *ibp = &rcd->ppd->ibport_data; + struct qib_other_headers *ohdr; + u32 opcode; + u32 hdrsize; + u32 psn; + u32 pad; + struct ib_wc wc; + u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu); + int diff; + struct ib_reth *reth; + unsigned long flags; + int ret; + + /* Check for GRH */ + if (!has_grh) { + ohdr = &hdr->u.oth; + hdrsize = 8 + 12; /* LRH + BTH */ + } else { + ohdr = &hdr->u.l.oth; + hdrsize = 8 + 40 + 12; /* LRH + GRH + BTH */ + } + + opcode = be32_to_cpu(ohdr->bth[0]); + spin_lock_irqsave(&qp->s_lock, flags); + if (qib_ruc_check_hdr(ibp, hdr, has_grh, qp, opcode)) + goto sunlock; + spin_unlock_irqrestore(&qp->s_lock, flags); + + psn = be32_to_cpu(ohdr->bth[2]); + opcode >>= 24; + + /* Prevent simultaneous processing after APM on different CPUs */ + spin_lock(&qp->r_lock); + + /* + * Process responses (ACKs) before anything else. Note that the + * packet sequence number will be for something in the send work + * queue rather than the expected receive packet sequence number. + * In other words, this QP is the requester. + */ + if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) && + opcode <= OP(ATOMIC_ACKNOWLEDGE)) { + qib_rc_rcv_resp(ibp, ohdr, data, tlen, qp, opcode, psn, + hdrsize, pmtu, rcd); + goto runlock; + } + + /* Compute 24 bits worth of difference. */ + diff = qib_cmp24(psn, qp->r_psn); + if (unlikely(diff)) { + if (qib_rc_rcv_error(ohdr, data, qp, opcode, psn, diff, rcd)) + goto runlock; + goto send_ack; + } + + /* Check for opcode sequence errors. */ + switch (qp->r_state) { + case OP(SEND_FIRST): + case OP(SEND_MIDDLE): + if (opcode == OP(SEND_MIDDLE) || + opcode == OP(SEND_LAST) || + opcode == OP(SEND_LAST_WITH_IMMEDIATE)) + break; + goto nack_inv; + + case OP(RDMA_WRITE_FIRST): + case OP(RDMA_WRITE_MIDDLE): + if (opcode == OP(RDMA_WRITE_MIDDLE) || + opcode == OP(RDMA_WRITE_LAST) || + opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE)) + break; + goto nack_inv; + + default: + if (opcode == OP(SEND_MIDDLE) || + opcode == OP(SEND_LAST) || + opcode == OP(SEND_LAST_WITH_IMMEDIATE) || + opcode == OP(RDMA_WRITE_MIDDLE) || + opcode == OP(RDMA_WRITE_LAST) || + opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE)) + goto nack_inv; + /* + * Note that it is up to the requester to not send a new + * RDMA read or atomic operation before receiving an ACK + * for the previous operation. + */ + break; + } + + memset(&wc, 0, sizeof wc); + + if (qp->state == IB_QPS_RTR && !(qp->r_flags & QIB_R_COMM_EST)) { + qp->r_flags |= QIB_R_COMM_EST; + if (qp->ibqp.event_handler) { + struct ib_event ev; + + ev.device = qp->ibqp.device; + ev.element.qp = &qp->ibqp; + ev.event = IB_EVENT_COMM_EST; + qp->ibqp.event_handler(&ev, qp->ibqp.qp_context); + } + } + + /* OK, process the packet. */ + switch (opcode) { + case OP(SEND_FIRST): + ret = qib_get_rwqe(qp, 0); + if (ret < 0) + goto nack_op_err; + if (!ret) + goto rnr_nak; + qp->r_rcv_len = 0; + /* FALLTHROUGH */ + case OP(SEND_MIDDLE): + case OP(RDMA_WRITE_MIDDLE): +send_middle: + /* Check for invalid length PMTU or posted rwqe len. */ + if (unlikely(tlen != (hdrsize + pmtu + 4))) + goto nack_inv; + qp->r_rcv_len += pmtu; + if (unlikely(qp->r_rcv_len > qp->r_len)) + goto nack_inv; + qib_copy_sge(&qp->r_sge, data, pmtu, 1); + break; + + case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE): + /* consume RWQE */ + ret = qib_get_rwqe(qp, 1); + if (ret < 0) + goto nack_op_err; + if (!ret) + goto rnr_nak; + goto send_last_imm; + + case OP(SEND_ONLY): + case OP(SEND_ONLY_WITH_IMMEDIATE): + ret = qib_get_rwqe(qp, 0); + if (ret < 0) + goto nack_op_err; + if (!ret) + goto rnr_nak; + qp->r_rcv_len = 0; + if (opcode == OP(SEND_ONLY)) + goto send_last; + /* FALLTHROUGH */ + case OP(SEND_LAST_WITH_IMMEDIATE): +send_last_imm: + wc.ex.imm_data = ohdr->u.imm_data; + hdrsize += 4; + wc.wc_flags = IB_WC_WITH_IMM; + /* FALLTHROUGH */ + case OP(SEND_LAST): + case OP(RDMA_WRITE_LAST): +send_last: + /* Get the number of bytes the message was padded by. */ + pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3; + /* Check for invalid length. */ + /* XXX LAST len should be >= 1 */ + if (unlikely(tlen < (hdrsize + pad + 4))) + goto nack_inv; + /* Don't count the CRC. */ + tlen -= (hdrsize + pad + 4); + wc.byte_len = tlen + qp->r_rcv_len; + if (unlikely(wc.byte_len > qp->r_len)) + goto nack_inv; + qib_copy_sge(&qp->r_sge, data, tlen, 1); + while (qp->r_sge.num_sge) { + atomic_dec(&qp->r_sge.sge.mr->refcount); + if (--qp->r_sge.num_sge) + qp->r_sge.sge = *qp->r_sge.sg_list++; + } + qp->r_msn++; + if (!test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags)) + break; + wc.wr_id = qp->r_wr_id; + wc.status = IB_WC_SUCCESS; + if (opcode == OP(RDMA_WRITE_LAST_WITH_IMMEDIATE) || + opcode == OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE)) + wc.opcode = IB_WC_RECV_RDMA_WITH_IMM; + else + wc.opcode = IB_WC_RECV; + wc.qp = &qp->ibqp; + wc.src_qp = qp->remote_qpn; + wc.slid = qp->remote_ah_attr.dlid; + wc.sl = qp->remote_ah_attr.sl; + /* Signal completion event if the solicited bit is set. */ + qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, + (ohdr->bth[0] & + cpu_to_be32(IB_BTH_SOLICITED)) != 0); + break; + + case OP(RDMA_WRITE_FIRST): + case OP(RDMA_WRITE_ONLY): + case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE): + if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE))) + goto nack_inv; + /* consume RWQE */ + reth = &ohdr->u.rc.reth; + hdrsize += sizeof(*reth); + qp->r_len = be32_to_cpu(reth->length); + qp->r_rcv_len = 0; + qp->r_sge.sg_list = NULL; + if (qp->r_len != 0) { + u32 rkey = be32_to_cpu(reth->rkey); + u64 vaddr = be64_to_cpu(reth->vaddr); + int ok; + + /* Check rkey & NAK */ + ok = qib_rkey_ok(qp, &qp->r_sge.sge, qp->r_len, vaddr, + rkey, IB_ACCESS_REMOTE_WRITE); + if (unlikely(!ok)) + goto nack_acc; + qp->r_sge.num_sge = 1; + } else { + qp->r_sge.num_sge = 0; + qp->r_sge.sge.mr = NULL; + qp->r_sge.sge.vaddr = NULL; + qp->r_sge.sge.length = 0; + qp->r_sge.sge.sge_length = 0; + } + if (opcode == OP(RDMA_WRITE_FIRST)) + goto send_middle; + else if (opcode == OP(RDMA_WRITE_ONLY)) + goto send_last; + ret = qib_get_rwqe(qp, 1); + if (ret < 0) + goto nack_op_err; + if (!ret) + goto rnr_nak; + goto send_last_imm; + + case OP(RDMA_READ_REQUEST): { + struct qib_ack_entry *e; + u32 len; + u8 next; + + if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ))) + goto nack_inv; + next = qp->r_head_ack_queue + 1; + /* s_ack_queue is size QIB_MAX_RDMA_ATOMIC+1 so use > not >= */ + if (next > QIB_MAX_RDMA_ATOMIC) + next = 0; + spin_lock_irqsave(&qp->s_lock, flags); + /* Double check we can process this while holding the s_lock. */ + if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) + goto srunlock; + if (unlikely(next == qp->s_tail_ack_queue)) { + if (!qp->s_ack_queue[next].sent) + goto nack_inv_unlck; + qib_update_ack_queue(qp, next); + } + e = &qp->s_ack_queue[qp->r_head_ack_queue]; + if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) { + atomic_dec(&e->rdma_sge.mr->refcount); + e->rdma_sge.mr = NULL; + } + reth = &ohdr->u.rc.reth; + len = be32_to_cpu(reth->length); + if (len) { + u32 rkey = be32_to_cpu(reth->rkey); + u64 vaddr = be64_to_cpu(reth->vaddr); + int ok; + + /* Check rkey & NAK */ + ok = qib_rkey_ok(qp, &e->rdma_sge, len, vaddr, + rkey, IB_ACCESS_REMOTE_READ); + if (unlikely(!ok)) + goto nack_acc_unlck; + /* + * Update the next expected PSN. We add 1 later + * below, so only add the remainder here. + */ + if (len > pmtu) + qp->r_psn += (len - 1) / pmtu; + } else { + e->rdma_sge.mr = NULL; + e->rdma_sge.vaddr = NULL; + e->rdma_sge.length = 0; + e->rdma_sge.sge_length = 0; + } + e->opcode = opcode; + e->sent = 0; + e->psn = psn; + e->lpsn = qp->r_psn; + /* + * We need to increment the MSN here instead of when we + * finish sending the result since a duplicate request would + * increment it more than once. + */ + qp->r_msn++; + qp->r_psn++; + qp->r_state = opcode; + qp->r_nak_state = 0; + qp->r_head_ack_queue = next; + + /* Schedule the send tasklet. */ + qp->s_flags |= QIB_S_RESP_PENDING; + qib_schedule_send(qp); + + goto srunlock; + } + + case OP(COMPARE_SWAP): + case OP(FETCH_ADD): { + struct ib_atomic_eth *ateth; + struct qib_ack_entry *e; + u64 vaddr; + atomic64_t *maddr; + u64 sdata; + u32 rkey; + u8 next; + + if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC))) + goto nack_inv; + next = qp->r_head_ack_queue + 1; + if (next > QIB_MAX_RDMA_ATOMIC) + next = 0; + spin_lock_irqsave(&qp->s_lock, flags); + /* Double check we can process this while holding the s_lock. */ + if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) + goto srunlock; + if (unlikely(next == qp->s_tail_ack_queue)) { + if (!qp->s_ack_queue[next].sent) + goto nack_inv_unlck; + qib_update_ack_queue(qp, next); + } + e = &qp->s_ack_queue[qp->r_head_ack_queue]; + if (e->opcode == OP(RDMA_READ_REQUEST) && e->rdma_sge.mr) { + atomic_dec(&e->rdma_sge.mr->refcount); + e->rdma_sge.mr = NULL; + } + ateth = &ohdr->u.atomic_eth; + vaddr = ((u64) be32_to_cpu(ateth->vaddr[0]) << 32) | + be32_to_cpu(ateth->vaddr[1]); + if (unlikely(vaddr & (sizeof(u64) - 1))) + goto nack_inv_unlck; + rkey = be32_to_cpu(ateth->rkey); + /* Check rkey & NAK */ + if (unlikely(!qib_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64), + vaddr, rkey, + IB_ACCESS_REMOTE_ATOMIC))) + goto nack_acc_unlck; + /* Perform atomic OP and save result. */ + maddr = (atomic64_t *) qp->r_sge.sge.vaddr; + sdata = be64_to_cpu(ateth->swap_data); + e->atomic_data = (opcode == OP(FETCH_ADD)) ? + (u64) atomic64_add_return(sdata, maddr) - sdata : + (u64) cmpxchg((u64 *) qp->r_sge.sge.vaddr, + be64_to_cpu(ateth->compare_data), + sdata); + atomic_dec(&qp->r_sge.sge.mr->refcount); + qp->r_sge.num_sge = 0; + e->opcode = opcode; + e->sent = 0; + e->psn = psn; + e->lpsn = psn; + qp->r_msn++; + qp->r_psn++; + qp->r_state = opcode; + qp->r_nak_state = 0; + qp->r_head_ack_queue = next; + + /* Schedule the send tasklet. */ + qp->s_flags |= QIB_S_RESP_PENDING; + qib_schedule_send(qp); + + goto srunlock; + } + + default: + /* NAK unknown opcodes. */ + goto nack_inv; + } + qp->r_psn++; + qp->r_state = opcode; + qp->r_ack_psn = psn; + qp->r_nak_state = 0; + /* Send an ACK if requested or required. */ + if (psn & (1 << 31)) + goto send_ack; + goto runlock; + +rnr_nak: + qp->r_nak_state = IB_RNR_NAK | qp->r_min_rnr_timer; + qp->r_ack_psn = qp->r_psn; + /* Queue RNR NAK for later */ + if (list_empty(&qp->rspwait)) { + qp->r_flags |= QIB_R_RSP_NAK; + atomic_inc(&qp->refcount); + list_add_tail(&qp->rspwait, &rcd->qp_wait_list); + } + goto runlock; + +nack_op_err: + qib_rc_error(qp, IB_WC_LOC_QP_OP_ERR); + qp->r_nak_state = IB_NAK_REMOTE_OPERATIONAL_ERROR; + qp->r_ack_psn = qp->r_psn; + /* Queue NAK for later */ + if (list_empty(&qp->rspwait)) { + qp->r_flags |= QIB_R_RSP_NAK; + atomic_inc(&qp->refcount); + list_add_tail(&qp->rspwait, &rcd->qp_wait_list); + } + goto runlock; + +nack_inv_unlck: + spin_unlock_irqrestore(&qp->s_lock, flags); +nack_inv: + qib_rc_error(qp, IB_WC_LOC_QP_OP_ERR); + qp->r_nak_state = IB_NAK_INVALID_REQUEST; + qp->r_ack_psn = qp->r_psn; + /* Queue NAK for later */ + if (list_empty(&qp->rspwait)) { + qp->r_flags |= QIB_R_RSP_NAK; + atomic_inc(&qp->refcount); + list_add_tail(&qp->rspwait, &rcd->qp_wait_list); + } + goto runlock; + +nack_acc_unlck: + spin_unlock_irqrestore(&qp->s_lock, flags); +nack_acc: + qib_rc_error(qp, IB_WC_LOC_PROT_ERR); + qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR; + qp->r_ack_psn = qp->r_psn; +send_ack: + qib_send_rc_ack(qp); +runlock: + spin_unlock(&qp->r_lock); + return; + +srunlock: + spin_unlock_irqrestore(&qp->s_lock, flags); + spin_unlock(&qp->r_lock); + return; + +sunlock: + spin_unlock_irqrestore(&qp->s_lock, flags); +} |
