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linux/drivers/infiniband/hw/qib/qib_rc.c
Mike Marciniszyn 6a82649f21 IB/qib: Avoid returning EBUSY from MR deregister 
A timing issue can occur where qib_mr_dereg can return -EBUSY if the
MR use count is not zero.

This can occur if the MR is de-registered while RDMA read response
packets are being progressed from the SDMA ring.  The suspicion is
that the peer sent an RDMA read request, which has already been copied
across to the peer.  The peer sees the completion of his request and
then communicates to the responder that the MR is not needed any
longer.  The responder tries to de-register the MR, catching some
responses remaining in the SDMA ring holding the MR use count.

The code now uses a get/put paradigm to track MR use counts and
coordinates with the MR de-registration process using a completion
when the count has reached zero.  A timeout on the delay is in place
to catch other EBUSY issues.

The reference count protocol is as follows:
- The return to the user counts as 1
- A reference from the lk_table or the qib_ibdev counts as 1.
- Transient I/O operations increase/decrease as necessary

A lot of code duplication has been folded into the new routines
init_qib_mregion() and deinit_qib_mregion().  Additionally, explicit
initialization of fields to zero is now handled by kzalloc().

Also, duplicated code 'while.*num_sge' that decrements reference
counts have been consolidated in qib_put_ss().

Reviewed-by: Ramkrishna Vepa <ramkrishna.vepa@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-07-08 18:05:19 -07:00

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/*
* 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 + qp->timeout_jiffies;
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) {
qib_put_mr(e->rdma_sge.mr);
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)
qib_get_mr(qp->s_rdma_mr);
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)
qib_get_mr(qp->s_rdma_mr);
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 = qp->pmtu;
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);
qib_send_complete(qp, wqe, qp->s_last != qp->s_acked ?
IB_WC_SUCCESS : IB_WC_WR_FLUSH_ERR);
/* will get called again */
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)) &&
(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK))
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];
qib_put_mr(sge->mr);
}
/* 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];
qib_put_mr(sge->mr);
}
/* 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;
struct qib_pportdata *ppd = ppd_from_ibp(ibp);
enum ib_wc_status status;
unsigned long flags;
int diff;
u32 pad;
u32 aeth;
u64 val;
if (opcode != OP(RDMA_READ_RESPONSE_MIDDLE)) {
/*
* If ACK'd PSN on SDMA busy list try to make progress to
* reclaim SDMA credits.
*/
if ((qib_cmp24(psn, qp->s_sending_psn) >= 0) &&
(qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)) {
/*
* If send tasklet not running attempt to progress
* SDMA queue.
*/
if (!(qp->s_flags & QIB_S_BUSY)) {
/* Acquire SDMA Lock */
spin_lock_irqsave(&ppd->sdma_lock, flags);
/* Invoke sdma make progress */
qib_sdma_make_progress(ppd);
/* Release SDMA Lock */
spin_unlock_irqrestore(&ppd->sdma_lock, flags);
}
}
}
spin_lock_irqsave(&qp->s_lock, flags);
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 + qp->timeout_jiffies);
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) *
qp->pmtu;
len = be32_to_cpu(reth->length);
if (unlikely(offset + len != e->rdma_sge.sge_length))
goto unlock_done;
if (e->rdma_sge.mr) {
qib_put_mr(e->rdma_sge.mr);
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 = qp->pmtu;
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]);
if (qib_ruc_check_hdr(ibp, hdr, has_grh, qp, opcode))
return;
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;
}
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 no_immediate_data;
/* FALLTHROUGH for SEND_ONLY_WITH_IMMEDIATE */
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;
goto send_last;
case OP(SEND_LAST):
case OP(RDMA_WRITE_LAST):
no_immediate_data:
wc.wc_flags = 0;
wc.ex.imm_data = 0;
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);
qib_put_ss(&qp->r_sge);
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;
/* zero fields that are N/A */
wc.vendor_err = 0;
wc.pkey_index = 0;
wc.dlid_path_bits = 0;
wc.port_num = 0;
/* 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 no_immediate_data;
ret = qib_get_rwqe(qp, 1);
if (ret < 0)
goto nack_op_err;
if (!ret)
goto rnr_nak;
wc.ex.imm_data = ohdr->u.rc.imm_data;
hdrsize += 4;
wc.wc_flags = IB_WC_WITH_IMM;
goto send_last;
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) {
qib_put_mr(e->rdma_sge.mr);
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) {
qib_put_mr(e->rdma_sge.mr);
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);
qib_put_mr(qp->r_sge.sge.mr);
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);
}
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