* @qp: the QP who's SGE we're restarting
* @wqe: the work queue to initialize the QP's SGE from
*
- * The QP s_lock should be held.
+ * The QP s_lock should be held and interrupts disabled.
*/
static void ipath_init_restart(struct ipath_qp *qp, struct ipath_swqe *wqe)
{
struct ipath_other_headers *ohdr,
u32 pmtu)
{
- struct ipath_sge_state *ss;
u32 hwords;
u32 len;
u32 bth0;
*/
switch (qp->s_ack_state) {
case OP(RDMA_READ_REQUEST):
- ss = &qp->s_rdma_sge;
+ qp->s_cur_sge = &qp->s_rdma_sge;
len = qp->s_rdma_len;
if (len > pmtu) {
len = pmtu;
qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
/* FALLTHROUGH */
case OP(RDMA_READ_RESPONSE_MIDDLE):
- ss = &qp->s_rdma_sge;
+ qp->s_cur_sge = &qp->s_rdma_sge;
len = qp->s_rdma_len;
if (len > pmtu)
len = pmtu;
* We have to prevent new requests from changing
* the r_sge state while a ipath_verbs_send()
* is in progress.
- * Changing r_state allows the receiver
- * to continue processing new packets.
- * We do it here now instead of above so
- * that we are sure the packet was sent before
- * changing the state.
*/
- qp->r_state = OP(RDMA_READ_RESPONSE_LAST);
qp->s_ack_state = OP(ACKNOWLEDGE);
- return 0;
+ bth0 = 0;
+ goto bail;
case OP(COMPARE_SWAP):
case OP(FETCH_ADD):
- ss = NULL;
+ qp->s_cur_sge = NULL;
len = 0;
- qp->r_state = OP(SEND_LAST);
- qp->s_ack_state = OP(ACKNOWLEDGE);
- bth0 = IB_OPCODE_ATOMIC_ACKNOWLEDGE << 24;
+ /*
+ * Set the s_ack_state so the receive interrupt handler
+ * won't try to send an ACK (out of order) until this one
+ * is actually sent.
+ */
+ qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
+ bth0 = OP(ATOMIC_ACKNOWLEDGE) << 24;
ohdr->u.at.aeth = ipath_compute_aeth(qp);
- ohdr->u.at.atomic_ack_eth = cpu_to_be64(qp->s_ack_atomic);
+ ohdr->u.at.atomic_ack_eth = cpu_to_be64(qp->r_atomic_data);
hwords += sizeof(ohdr->u.at) / 4;
break;
default:
/* Send a regular ACK. */
- ss = NULL;
+ qp->s_cur_sge = NULL;
len = 0;
- qp->s_ack_state = OP(ACKNOWLEDGE);
- bth0 = qp->s_ack_state << 24;
- ohdr->u.aeth = ipath_compute_aeth(qp);
+ /*
+ * Set the s_ack_state so the receive interrupt handler
+ * won't try to send an ACK (out of order) until this one
+ * is actually sent.
+ */
+ qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
+ bth0 = OP(ACKNOWLEDGE) << 24;
+ if (qp->s_nak_state)
+ ohdr->u.aeth = cpu_to_be32((qp->r_msn & IPS_MSN_MASK) |
+ (qp->s_nak_state <<
+ IPS_AETH_CREDIT_SHIFT));
+ else
+ ohdr->u.aeth = ipath_compute_aeth(qp);
hwords++;
}
qp->s_hdrwords = hwords;
- qp->s_cur_sge = ss;
qp->s_cur_size = len;
+bail:
return bth0;
}
* @bth2p: pointer to the BTH PSN word
*
* Return 1 if constructed; otherwise, return 0.
- * Note the QP s_lock must be held.
+ * Note the QP s_lock must be held and interrupts disabled.
*/
int ipath_make_rc_req(struct ipath_qp *qp,
struct ipath_other_headers *ohdr,
bth2 |= qp->s_psn++ & IPS_PSN_MASK;
if ((int)(qp->s_psn - qp->s_next_psn) > 0)
qp->s_next_psn = qp->s_psn;
+ /*
+ * Put the QP on the pending list so lost ACKs will cause
+ * a retry. More than one request can be pending so the
+ * QP may already be on the dev->pending list.
+ */
spin_lock(&dev->pending_lock);
if (list_empty(&qp->timerwait))
list_add_tail(&qp->timerwait,
case OP(RDMA_READ_RESPONSE_FIRST):
/*
- * This case can only happen if a send is restarted. See
- * ipath_restart_rc().
+ * This case can only happen if a send is restarted.
+ * See ipath_restart_rc().
*/
ipath_init_restart(qp, wqe);
/* FALLTHROUGH */
ohdr = &hdr.u.l.oth;
lrh0 = IPS_LRH_GRH;
}
+ /* read pkey_index w/o lock (its atomic) */
bth0 = ipath_layer_get_pkey(dev->dd, qp->s_pkey_index);
- ohdr->u.aeth = ipath_compute_aeth(qp);
- if (qp->s_ack_state >= OP(COMPARE_SWAP)) {
- bth0 |= IB_OPCODE_ATOMIC_ACKNOWLEDGE << 24;
- ohdr->u.at.atomic_ack_eth = cpu_to_be64(qp->s_ack_atomic);
+ if (qp->r_nak_state)
+ ohdr->u.aeth = cpu_to_be32((qp->r_msn & IPS_MSN_MASK) |
+ (qp->r_nak_state <<
+ IPS_AETH_CREDIT_SHIFT));
+ else
+ ohdr->u.aeth = ipath_compute_aeth(qp);
+ if (qp->r_ack_state >= OP(COMPARE_SWAP)) {
+ bth0 |= OP(ATOMIC_ACKNOWLEDGE) << 24;
+ ohdr->u.at.atomic_ack_eth = cpu_to_be64(qp->r_atomic_data);
hwords += sizeof(ohdr->u.at.atomic_ack_eth) / 4;
} else
bth0 |= OP(ACKNOWLEDGE) << 24;
hdr.lrh[3] = cpu_to_be16(ipath_layer_get_lid(dev->dd));
ohdr->bth[0] = cpu_to_be32(bth0);
ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
- ohdr->bth[2] = cpu_to_be32(qp->s_ack_psn & IPS_PSN_MASK);
+ ohdr->bth[2] = cpu_to_be32(qp->r_ack_psn & IPS_PSN_MASK);
/*
* If we can send the ACK, clear the ACK state.
*/
if (ipath_verbs_send(dev->dd, hwords, (u32 *) &hdr, 0, NULL) == 0) {
- qp->s_ack_state = OP(ACKNOWLEDGE);
- dev->n_rc_qacks++;
+ qp->r_ack_state = OP(ACKNOWLEDGE);
dev->n_unicast_xmit++;
+ } else {
+ /*
+ * 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.
+ */
+ dev->n_rc_qacks++;
+ spin_lock_irq(&qp->s_lock);
+ /* Don't coalesce if a RDMA read or atomic is pending. */
+ if (qp->s_ack_state == OP(ACKNOWLEDGE) ||
+ qp->s_ack_state < OP(RDMA_READ_REQUEST)) {
+ qp->s_ack_state = qp->r_ack_state;
+ qp->s_nak_state = qp->r_nak_state;
+ qp->s_ack_psn = qp->r_ack_psn;
+ qp->r_ack_state = OP(ACKNOWLEDGE);
+ }
+ spin_unlock_irq(&qp->s_lock);
+
+ /* Call ipath_do_rc_send() in another thread. */
+ tasklet_hi_schedule(&qp->s_task);
}
}
* @psn: packet sequence number for the request
* @wc: the work completion request
*
- * The QP s_lock should be held.
+ * The QP s_lock should be held and interrupts disabled.
*/
void ipath_restart_rc(struct ipath_qp *qp, u32 psn, struct ib_wc *wc)
{
*
* This is called from ipath_rc_rcv_resp() to process an incoming RC ACK
* for the given QP.
- * Called at interrupt level with the QP s_lock held.
+ * Called at interrupt level with the QP s_lock held and interrupts disabled.
* Returns 1 if OK, 0 if current operation should be aborted (NAK).
*/
static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode)
* Don't queue the NAK if a RDMA read, atomic, or
* NAK is pending though.
*/
- spin_lock(&qp->s_lock);
- if ((qp->s_ack_state >= OP(RDMA_READ_REQUEST) &&
- qp->s_ack_state != IB_OPCODE_ACKNOWLEDGE) ||
- qp->s_nak_state != 0) {
- spin_unlock(&qp->s_lock);
+ if (qp->s_ack_state != OP(ACKNOWLEDGE) ||
+ qp->r_nak_state != 0)
goto done;
+ if (qp->r_ack_state < OP(COMPARE_SWAP)) {
+ qp->r_ack_state = OP(SEND_ONLY);
+ qp->r_nak_state = IB_NAK_PSN_ERROR;
+ /* Use the expected PSN. */
+ qp->r_ack_psn = qp->r_psn;
}
- qp->s_ack_state = OP(SEND_ONLY);
- qp->s_nak_state = IB_NAK_PSN_ERROR;
- /* Use the expected PSN. */
- qp->s_ack_psn = qp->r_psn;
- goto resched;
+ goto send_ack;
}
/*
* send the earliest so that RDMA reads can be restarted at
* the requester's expected PSN.
*/
- spin_lock(&qp->s_lock);
- if (qp->s_ack_state != IB_OPCODE_ACKNOWLEDGE &&
- ipath_cmp24(psn, qp->s_ack_psn) >= 0) {
- if (qp->s_ack_state < IB_OPCODE_RDMA_READ_REQUEST)
- qp->s_ack_psn = psn;
- spin_unlock(&qp->s_lock);
- goto done;
- }
- switch (opcode) {
- case OP(RDMA_READ_REQUEST):
- /*
- * We have to be careful to not change s_rdma_sge
- * while ipath_do_rc_send() is using it and not
- * holding the s_lock.
- */
- if (qp->s_ack_state != OP(ACKNOWLEDGE) &&
- qp->s_ack_state >= IB_OPCODE_RDMA_READ_REQUEST) {
- spin_unlock(&qp->s_lock);
- dev->n_rdma_dup_busy++;
- goto done;
- }
+ if (opcode == OP(RDMA_READ_REQUEST)) {
/* RETH comes after BTH */
if (!header_in_data)
reth = &ohdr->u.rc.reth;
reth = (struct ib_reth *)data;
data += sizeof(*reth);
}
+ /*
+ * If we receive a duplicate RDMA request, it means the
+ * requester saw a sequence error and needs to restart
+ * from an earlier point. We can abort the current
+ * RDMA read send in that case.
+ */
+ spin_lock_irq(&qp->s_lock);
+ if (qp->s_ack_state != OP(ACKNOWLEDGE) &&
+ (qp->s_hdrwords || ipath_cmp24(psn, qp->s_ack_psn) >= 0)) {
+ /*
+ * We are already sending earlier requested data.
+ * Don't abort it to send later out of sequence data.
+ */
+ spin_unlock_irq(&qp->s_lock);
+ goto done;
+ }
qp->s_rdma_len = be32_to_cpu(reth->length);
if (qp->s_rdma_len != 0) {
u32 rkey = be32_to_cpu(reth->rkey);
ok = ipath_rkey_ok(dev, &qp->s_rdma_sge,
qp->s_rdma_len, vaddr, rkey,
IB_ACCESS_REMOTE_READ);
- if (unlikely(!ok))
+ if (unlikely(!ok)) {
+ spin_unlock_irq(&qp->s_lock);
goto done;
+ }
} else {
qp->s_rdma_sge.sg_list = NULL;
qp->s_rdma_sge.num_sge = 0;
qp->s_rdma_sge.sge.length = 0;
qp->s_rdma_sge.sge.sge_length = 0;
}
- break;
+ qp->s_ack_state = opcode;
+ qp->s_ack_psn = psn;
+ spin_unlock_irq(&qp->s_lock);
+ tasklet_hi_schedule(&qp->s_task);
+ goto send_ack;
+ }
+
+ /*
+ * A pending RDMA read will ACK anything before it so
+ * ignore earlier duplicate requests.
+ */
+ if (qp->s_ack_state != OP(ACKNOWLEDGE))
+ goto done;
+ /*
+ * If an ACK is pending, don't replace the pending ACK
+ * with an earlier one since the later one will ACK the earlier.
+ * Also, if we already have a pending atomic, send it.
+ */
+ if (qp->r_ack_state != OP(ACKNOWLEDGE) &&
+ (ipath_cmp24(psn, qp->r_ack_psn) <= 0 ||
+ qp->r_ack_state >= OP(COMPARE_SWAP)))
+ goto send_ack;
+ switch (opcode) {
case OP(COMPARE_SWAP):
case OP(FETCH_ADD):
/*
* Check for the PSN of the last atomic operation
* performed and resend the result if found.
*/
- if ((psn & IPS_PSN_MASK) != qp->r_atomic_psn) {
- spin_unlock(&qp->s_lock);
+ if ((psn & IPS_PSN_MASK) != qp->r_atomic_psn)
goto done;
- }
- qp->s_ack_atomic = qp->r_atomic_data;
break;
}
- qp->s_ack_state = opcode;
- qp->s_nak_state = 0;
- qp->s_ack_psn = psn;
-resched:
+ qp->r_ack_state = opcode;
+ qp->r_nak_state = 0;
+ qp->r_ack_psn = psn;
+send_ack:
return 0;
done:
u32 hdrsize;
u32 psn;
u32 pad;
- unsigned long flags;
struct ib_wc wc;
u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
int diff;
opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
ipath_rc_rcv_resp(dev, ohdr, data, tlen, qp, opcode, psn,
hdrsize, pmtu, header_in_data);
- goto bail;
+ goto done;
}
- spin_lock_irqsave(&qp->r_rq.lock, flags);
-
/* Compute 24 bits worth of difference. */
diff = ipath_cmp24(psn, qp->r_psn);
if (unlikely(diff)) {
if (ipath_rc_rcv_error(dev, ohdr, data, qp, opcode,
psn, diff, header_in_data))
goto done;
- goto resched;
+ goto send_ack;
}
/* Check for opcode sequence errors. */
opcode == OP(SEND_LAST_WITH_IMMEDIATE))
break;
nack_inv:
- /*
- * A NAK will ACK earlier sends and RDMA writes. Don't queue the
- * NAK if a RDMA read, atomic, or NAK is pending though.
- */
- spin_lock(&qp->s_lock);
- if (qp->s_ack_state >= OP(RDMA_READ_REQUEST) &&
- qp->s_ack_state != IB_OPCODE_ACKNOWLEDGE) {
- spin_unlock(&qp->s_lock);
- goto done;
- }
- /* XXX Flush WQEs */
- qp->state = IB_QPS_ERR;
- qp->s_ack_state = OP(SEND_ONLY);
- qp->s_nak_state = IB_NAK_INVALID_REQUEST;
- qp->s_ack_psn = qp->r_psn;
- goto resched;
+ /*
+ * A NAK will ACK earlier sends and RDMA writes.
+ * Don't queue the NAK if a RDMA read, atomic, or NAK
+ * is pending though.
+ */
+ if (qp->r_ack_state >= OP(COMPARE_SWAP))
+ goto send_ack;
+ /* XXX Flush WQEs */
+ qp->state = IB_QPS_ERR;
+ qp->r_ack_state = OP(SEND_ONLY);
+ qp->r_nak_state = IB_NAK_INVALID_REQUEST;
+ qp->r_ack_psn = qp->r_psn;
+ goto send_ack;
case OP(RDMA_WRITE_FIRST):
case OP(RDMA_WRITE_MIDDLE):
break;
goto nack_inv;
- case OP(RDMA_READ_REQUEST):
- case OP(COMPARE_SWAP):
- case OP(FETCH_ADD):
- /*
- * Drop all new requests until a response has been sent. A
- * new request then ACKs the RDMA response we sent. Relaxed
- * ordering would allow new requests to be processed but we
- * would need to keep a queue of rwqe's for all that are in
- * progress. Note that we can't RNR NAK this request since
- * the RDMA READ or atomic response is already queued to be
- * sent (unless we implement a response send queue).
- */
- goto done;
-
default:
if (opcode == OP(SEND_MIDDLE) ||
opcode == OP(SEND_LAST) ||
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;
}
* Don't queue the NAK if a RDMA read or atomic
* is pending though.
*/
- spin_lock(&qp->s_lock);
- if (qp->s_ack_state >=
- OP(RDMA_READ_REQUEST) &&
- qp->s_ack_state != IB_OPCODE_ACKNOWLEDGE) {
- spin_unlock(&qp->s_lock);
- goto done;
- }
- qp->s_ack_state = OP(SEND_ONLY);
- qp->s_nak_state = IB_RNR_NAK | qp->s_min_rnr_timer;
- qp->s_ack_psn = qp->r_psn;
- goto resched;
+ if (qp->r_ack_state >= OP(COMPARE_SWAP))
+ goto send_ack;
+ qp->r_ack_state = OP(SEND_ONLY);
+ qp->r_nak_state = IB_RNR_NAK | qp->r_min_rnr_timer;
+ qp->r_ack_psn = qp->r_psn;
+ goto send_ack;
}
qp->r_rcv_len = 0;
/* FALLTHROUGH */
if (unlikely(wc.byte_len > qp->r_len))
goto nack_inv;
ipath_copy_sge(&qp->r_sge, data, tlen);
- atomic_inc(&qp->msn);
+ qp->r_msn++;
if (opcode == OP(RDMA_WRITE_LAST) ||
opcode == OP(RDMA_WRITE_ONLY))
break;
ok = ipath_rkey_ok(dev, &qp->r_sge,
qp->r_len, vaddr, rkey,
IB_ACCESS_REMOTE_WRITE);
- if (unlikely(!ok)) {
- nack_acc:
- /*
- * A NAK will ACK earlier sends and RDMA
- * writes. Don't queue the NAK if a RDMA
- * read, atomic, or NAK is pending though.
- */
- spin_lock(&qp->s_lock);
- if (qp->s_ack_state >=
- OP(RDMA_READ_REQUEST) &&
- qp->s_ack_state !=
- IB_OPCODE_ACKNOWLEDGE) {
- spin_unlock(&qp->s_lock);
- goto done;
- }
- /* XXX Flush WQEs */
- qp->state = IB_QPS_ERR;
- qp->s_ack_state = OP(RDMA_WRITE_ONLY);
- qp->s_nak_state =
- IB_NAK_REMOTE_ACCESS_ERROR;
- qp->s_ack_psn = qp->r_psn;
- goto resched;
- }
+ if (unlikely(!ok))
+ goto nack_acc;
} else {
qp->r_sge.sg_list = NULL;
qp->r_sge.sge.mr = NULL;
reth = (struct ib_reth *)data;
data += sizeof(*reth);
}
- spin_lock(&qp->s_lock);
- if (qp->s_ack_state != OP(ACKNOWLEDGE) &&
- qp->s_ack_state >= IB_OPCODE_RDMA_READ_REQUEST) {
- spin_unlock(&qp->s_lock);
- goto done;
- }
+ if (unlikely(!(qp->qp_access_flags &
+ IB_ACCESS_REMOTE_READ)))
+ goto nack_acc;
+ spin_lock_irq(&qp->s_lock);
qp->s_rdma_len = be32_to_cpu(reth->length);
if (qp->s_rdma_len != 0) {
u32 rkey = be32_to_cpu(reth->rkey);
qp->s_rdma_len, vaddr, rkey,
IB_ACCESS_REMOTE_READ);
if (unlikely(!ok)) {
- spin_unlock(&qp->s_lock);
+ spin_unlock_irq(&qp->s_lock);
goto nack_acc;
}
/*
qp->s_rdma_sge.sge.length = 0;
qp->s_rdma_sge.sge.sge_length = 0;
}
- if (unlikely(!(qp->qp_access_flags &
- IB_ACCESS_REMOTE_READ)))
- goto nack_acc;
/*
* 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.
*/
- atomic_inc(&qp->msn);
+ qp->r_msn++;
+
qp->s_ack_state = opcode;
- qp->s_nak_state = 0;
qp->s_ack_psn = psn;
+ spin_unlock_irq(&qp->s_lock);
+
qp->r_psn++;
qp->r_state = opcode;
- goto rdmadone;
+ qp->r_nak_state = 0;
+
+ /* Call ipath_do_rc_send() in another thread. */
+ tasklet_hi_schedule(&qp->s_task);
+
+ goto done;
case OP(COMPARE_SWAP):
case OP(FETCH_ADD): {
goto nack_acc;
/* Perform atomic OP and save result. */
sdata = be64_to_cpu(ateth->swap_data);
- spin_lock(&dev->pending_lock);
+ spin_lock_irq(&dev->pending_lock);
qp->r_atomic_data = *(u64 *) qp->r_sge.sge.vaddr;
if (opcode == OP(FETCH_ADD))
*(u64 *) qp->r_sge.sge.vaddr =
else if (qp->r_atomic_data ==
be64_to_cpu(ateth->compare_data))
*(u64 *) qp->r_sge.sge.vaddr = sdata;
- spin_unlock(&dev->pending_lock);
- atomic_inc(&qp->msn);
+ spin_unlock_irq(&dev->pending_lock);
+ qp->r_msn++;
qp->r_atomic_psn = psn & IPS_PSN_MASK;
psn |= 1 << 31;
break;
}
qp->r_psn++;
qp->r_state = opcode;
+ qp->r_nak_state = 0;
/* Send an ACK if requested or required. */
if (psn & (1 << 31)) {
/*
* Coalesce ACKs unless there is a RDMA READ or
* ATOMIC pending.
*/
- spin_lock(&qp->s_lock);
- if (qp->s_ack_state == OP(ACKNOWLEDGE) ||
- qp->s_ack_state < IB_OPCODE_RDMA_READ_REQUEST) {
- qp->s_ack_state = opcode;
- qp->s_nak_state = 0;
- qp->s_ack_psn = psn;
- qp->s_ack_atomic = qp->r_atomic_data;
- goto resched;
+ if (qp->r_ack_state < OP(COMPARE_SWAP)) {
+ qp->r_ack_state = opcode;
+ qp->r_ack_psn = psn;
}
- spin_unlock(&qp->s_lock);
+ goto send_ack;
}
-done:
- spin_unlock_irqrestore(&qp->r_rq.lock, flags);
- goto bail;
+ goto done;
-resched:
+nack_acc:
/*
- * Try to send ACK right away but not if ipath_do_rc_send() is
- * active.
+ * A NAK will ACK earlier sends and RDMA writes.
+ * Don't queue the NAK if a RDMA read, atomic, or NAK
+ * is pending though.
*/
- if (qp->s_hdrwords == 0 &&
- (qp->s_ack_state < IB_OPCODE_RDMA_READ_REQUEST ||
- qp->s_ack_state >= IB_OPCODE_COMPARE_SWAP))
+ if (qp->r_ack_state < OP(COMPARE_SWAP)) {
+ /* XXX Flush WQEs */
+ qp->state = IB_QPS_ERR;
+ qp->r_ack_state = OP(RDMA_WRITE_ONLY);
+ qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
+ qp->r_ack_psn = qp->r_psn;
+ }
+send_ack:
+ /* Send ACK right away unless the send tasklet has a pending ACK. */
+ if (qp->s_ack_state == OP(ACKNOWLEDGE))
send_rc_ack(qp);
-rdmadone:
- spin_unlock(&qp->s_lock);
- spin_unlock_irqrestore(&qp->r_rq.lock, flags);
-
- /* Call ipath_do_rc_send() in another thread. */
- tasklet_hi_schedule(&qp->s_task);
-
-bail:
+done:
return;
}
projects / linux-2.6 / commitdiff