/*
* 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 r_lock and 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->r_lock, flags);
spin_lock(&qp->s_lock);
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(&qp->s_lock);
spin_unlock_irqrestore(&qp->r_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);
/* 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);
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;
/*
* 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);
return;
}
/* 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))
return;
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);
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 sunlock;
}
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);
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 sunlock;
}
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;
return;
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);
}
return;
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);
}
return;
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);
}
return;
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);
return;
sunlock:
spin_unlock_irqrestore(&qp->s_lock, flags);
}
