in sw/rdmavt/qp.c [2904:3211]
void rvt_ruc_loopback(struct rvt_qp *sqp)
{
struct rvt_ibport *rvp = NULL;
struct rvt_dev_info *rdi = ib_to_rvt(sqp->ibqp.device);
struct rvt_qp *qp;
struct rvt_swqe *wqe;
struct rvt_sge *sge;
unsigned long flags;
struct ib_wc wc;
u64 sdata;
atomic64_t *maddr;
enum ib_wc_status send_status;
bool release;
int ret;
bool copy_last = false;
int local_ops = 0;
rcu_read_lock();
rvp = rdi->ports[sqp->port_num - 1];
/*
* Note that we check the responder QP state after
* checking the requester's state.
*/
qp = rvt_lookup_qpn(ib_to_rvt(sqp->ibqp.device), rvp,
sqp->remote_qpn);
spin_lock_irqsave(&sqp->s_lock, flags);
/* Return if we are already busy processing a work request. */
if ((sqp->s_flags & (RVT_S_BUSY | RVT_S_ANY_WAIT)) ||
!(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_OR_FLUSH_SEND))
goto unlock;
sqp->s_flags |= RVT_S_BUSY;
again:
if (sqp->s_last == READ_ONCE(sqp->s_head))
goto clr_busy;
wqe = rvt_get_swqe_ptr(sqp, sqp->s_last);
/* Return if it is not OK to start a new work request. */
if (!(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_NEXT_SEND_OK)) {
if (!(ib_rvt_state_ops[sqp->state] & RVT_FLUSH_SEND))
goto clr_busy;
/* We are in the error state, flush the work request. */
send_status = IB_WC_WR_FLUSH_ERR;
goto flush_send;
}
/*
* We can rely on the entry not changing without the s_lock
* being held until we update s_last.
* We increment s_cur to indicate s_last is in progress.
*/
if (sqp->s_last == sqp->s_cur) {
if (++sqp->s_cur >= sqp->s_size)
sqp->s_cur = 0;
}
spin_unlock_irqrestore(&sqp->s_lock, flags);
if (!qp) {
send_status = loopback_qp_drop(rvp, sqp);
goto serr_no_r_lock;
}
spin_lock_irqsave(&qp->r_lock, flags);
if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK) ||
qp->ibqp.qp_type != sqp->ibqp.qp_type) {
send_status = loopback_qp_drop(rvp, sqp);
goto serr;
}
memset(&wc, 0, sizeof(wc));
send_status = IB_WC_SUCCESS;
release = true;
sqp->s_sge.sge = wqe->sg_list[0];
sqp->s_sge.sg_list = wqe->sg_list + 1;
sqp->s_sge.num_sge = wqe->wr.num_sge;
sqp->s_len = wqe->length;
switch (wqe->wr.opcode) {
case IB_WR_REG_MR:
goto send_comp;
case IB_WR_LOCAL_INV:
if (!(wqe->wr.send_flags & RVT_SEND_COMPLETION_ONLY)) {
if (rvt_invalidate_rkey(sqp,
wqe->wr.ex.invalidate_rkey))
send_status = IB_WC_LOC_PROT_ERR;
local_ops = 1;
}
goto send_comp;
case IB_WR_SEND_WITH_INV:
case IB_WR_SEND_WITH_IMM:
case IB_WR_SEND:
ret = rvt_get_rwqe(qp, false);
if (ret < 0)
goto op_err;
if (!ret)
goto rnr_nak;
if (wqe->length > qp->r_len)
goto inv_err;
switch (wqe->wr.opcode) {
case IB_WR_SEND_WITH_INV:
if (!rvt_invalidate_rkey(qp,
wqe->wr.ex.invalidate_rkey)) {
wc.wc_flags = IB_WC_WITH_INVALIDATE;
wc.ex.invalidate_rkey =
wqe->wr.ex.invalidate_rkey;
}
break;
case IB_WR_SEND_WITH_IMM:
wc.wc_flags = IB_WC_WITH_IMM;
wc.ex.imm_data = wqe->wr.ex.imm_data;
break;
default:
break;
}
break;
case IB_WR_RDMA_WRITE_WITH_IMM:
if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
goto inv_err;
wc.wc_flags = IB_WC_WITH_IMM;
wc.ex.imm_data = wqe->wr.ex.imm_data;
ret = rvt_get_rwqe(qp, true);
if (ret < 0)
goto op_err;
if (!ret)
goto rnr_nak;
/* skip copy_last set and qp_access_flags recheck */
goto do_write;
case IB_WR_RDMA_WRITE:
copy_last = rvt_is_user_qp(qp);
if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
goto inv_err;
do_write:
if (wqe->length == 0)
break;
if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, wqe->length,
wqe->rdma_wr.remote_addr,
wqe->rdma_wr.rkey,
IB_ACCESS_REMOTE_WRITE)))
goto acc_err;
qp->r_sge.sg_list = NULL;
qp->r_sge.num_sge = 1;
qp->r_sge.total_len = wqe->length;
break;
case IB_WR_RDMA_READ:
if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
goto inv_err;
if (unlikely(!rvt_rkey_ok(qp, &sqp->s_sge.sge, wqe->length,
wqe->rdma_wr.remote_addr,
wqe->rdma_wr.rkey,
IB_ACCESS_REMOTE_READ)))
goto acc_err;
release = false;
sqp->s_sge.sg_list = NULL;
sqp->s_sge.num_sge = 1;
qp->r_sge.sge = wqe->sg_list[0];
qp->r_sge.sg_list = wqe->sg_list + 1;
qp->r_sge.num_sge = wqe->wr.num_sge;
qp->r_sge.total_len = wqe->length;
break;
case IB_WR_ATOMIC_CMP_AND_SWP:
case IB_WR_ATOMIC_FETCH_AND_ADD:
if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
goto inv_err;
if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
wqe->atomic_wr.remote_addr,
wqe->atomic_wr.rkey,
IB_ACCESS_REMOTE_ATOMIC)))
goto acc_err;
/* Perform atomic OP and save result. */
maddr = (atomic64_t *)qp->r_sge.sge.vaddr;
sdata = wqe->atomic_wr.compare_add;
*(u64 *)sqp->s_sge.sge.vaddr =
(wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) ?
(u64)atomic64_add_return(sdata, maddr) - sdata :
(u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr,
sdata, wqe->atomic_wr.swap);
rvt_put_mr(qp->r_sge.sge.mr);
qp->r_sge.num_sge = 0;
goto send_comp;
default:
send_status = IB_WC_LOC_QP_OP_ERR;
goto serr;
}
sge = &sqp->s_sge.sge;
while (sqp->s_len) {
u32 len = rvt_get_sge_length(sge, sqp->s_len);
WARN_ON_ONCE(len == 0);
rvt_copy_sge(qp, &qp->r_sge, sge->vaddr,
len, release, copy_last);
rvt_update_sge(&sqp->s_sge, len, !release);
sqp->s_len -= len;
}
if (release)
rvt_put_ss(&qp->r_sge);
if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
goto send_comp;
if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM)
wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
else
wc.opcode = IB_WC_RECV;
wc.wr_id = qp->r_wr_id;
wc.status = IB_WC_SUCCESS;
wc.byte_len = wqe->length;
wc.qp = &qp->ibqp;
wc.src_qp = qp->remote_qpn;
wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
wc.port_num = 1;
/* Signal completion event if the solicited bit is set. */
rvt_recv_cq(qp, &wc, wqe->wr.send_flags & IB_SEND_SOLICITED);
send_comp:
spin_unlock_irqrestore(&qp->r_lock, flags);
spin_lock_irqsave(&sqp->s_lock, flags);
rvp->n_loop_pkts++;
flush_send:
sqp->s_rnr_retry = sqp->s_rnr_retry_cnt;
rvt_send_complete(sqp, wqe, send_status);
if (local_ops) {
atomic_dec(&sqp->local_ops_pending);
local_ops = 0;
}
goto again;
rnr_nak:
/* Handle RNR NAK */
if (qp->ibqp.qp_type == IB_QPT_UC)
goto send_comp;
rvp->n_rnr_naks++;
/*
* Note: we don't need the s_lock held since the BUSY flag
* makes this single threaded.
*/
if (sqp->s_rnr_retry == 0) {
send_status = IB_WC_RNR_RETRY_EXC_ERR;
goto serr;
}
if (sqp->s_rnr_retry_cnt < 7)
sqp->s_rnr_retry--;
spin_unlock_irqrestore(&qp->r_lock, flags);
spin_lock_irqsave(&sqp->s_lock, flags);
if (!(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_RECV_OK))
goto clr_busy;
rvt_add_rnr_timer(sqp, qp->r_min_rnr_timer <<
IB_AETH_CREDIT_SHIFT);
goto clr_busy;
op_err:
send_status = IB_WC_REM_OP_ERR;
wc.status = IB_WC_LOC_QP_OP_ERR;
goto err;
inv_err:
send_status =
sqp->ibqp.qp_type == IB_QPT_RC ?
IB_WC_REM_INV_REQ_ERR :
IB_WC_SUCCESS;
wc.status = IB_WC_LOC_QP_OP_ERR;
goto err;
acc_err:
send_status = IB_WC_REM_ACCESS_ERR;
wc.status = IB_WC_LOC_PROT_ERR;
err:
/* responder goes to error state */
rvt_rc_error(qp, wc.status);
serr:
spin_unlock_irqrestore(&qp->r_lock, flags);
serr_no_r_lock:
spin_lock_irqsave(&sqp->s_lock, flags);
rvt_send_complete(sqp, wqe, send_status);
if (sqp->ibqp.qp_type == IB_QPT_RC) {
int lastwqe = rvt_error_qp(sqp, IB_WC_WR_FLUSH_ERR);
sqp->s_flags &= ~RVT_S_BUSY;
spin_unlock_irqrestore(&sqp->s_lock, flags);
if (lastwqe) {
struct ib_event ev;
ev.device = sqp->ibqp.device;
ev.element.qp = &sqp->ibqp;
ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
sqp->ibqp.event_handler(&ev, sqp->ibqp.qp_context);
}
goto done;
}
clr_busy:
sqp->s_flags &= ~RVT_S_BUSY;
unlock:
spin_unlock_irqrestore(&sqp->s_lock, flags);
done:
rcu_read_unlock();
}