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android_kernel_xiaomi_sm8350/drivers/infiniband/hw/ipath/ipath_rc.c
Ralph Campbell 154257f362 IB/ipath: Fix a race condition when generating ACKs 
Fix a problem where simple ACKs can be sent ahead of RDMA read
responses thus implicitly NAKing the RDMA read.

Signed-off-by: Ralph Campbell <ralph.cambpell@qlogic.com>
Signed-off-by: Robert Walsh <robert.walsh@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2007-05-06 21:18:11 -07:00

1860 lines
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/*
* Copyright (c) 2006 QLogic, Inc. 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 "ipath_verbs.h"
#include "ipath_kernel.h"
/* cut down ridiculously long IB macro names */
#define OP(x) IB_OPCODE_RC_##x
static u32 restart_sge(struct ipath_sge_state *ss, struct ipath_swqe *wqe,
u32 psn, u32 pmtu)
{
u32 len;
len = ((psn - wqe->psn) & IPATH_PSN_MASK) * pmtu;
ss->sge = wqe->sg_list[0];
ss->sg_list = wqe->sg_list + 1;
ss->num_sge = wqe->wr.num_sge;
ipath_skip_sge(ss, len);
return wqe->length - len;
}
/**
* ipath_init_restart- initialize the qp->s_sge after a restart
* @qp: the QP who's SGE we're restarting
* @wqe: the work queue to initialize the QP's SGE from
*
* The QP s_lock should be held and interrupts disabled.
*/
static void ipath_init_restart(struct ipath_qp *qp, struct ipath_swqe *wqe)
{
struct ipath_ibdev *dev;
qp->s_len = restart_sge(&qp->s_sge, wqe, qp->s_psn,
ib_mtu_enum_to_int(qp->path_mtu));
dev = to_idev(qp->ibqp.device);
spin_lock(&dev->pending_lock);
if (list_empty(&qp->timerwait))
list_add_tail(&qp->timerwait,
&dev->pending[dev->pending_index]);
spin_unlock(&dev->pending_lock);
}
/**
* ipath_make_rc_ack - construct a response packet (ACK, NAK, or RDMA read)
* @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 ipath_make_rc_ack(struct ipath_qp *qp,
struct ipath_other_headers *ohdr,
u32 pmtu, u32 *bth0p, u32 *bth2p)
{
struct ipath_ack_entry *e;
u32 hwords;
u32 len;
u32 bth0;
u32 bth2;
/* 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):
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 > IPATH_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 & IPATH_S_ACK_PENDING)
goto normal;
qp->s_ack_state = OP(ACKNOWLEDGE);
goto bail;
}
e = &qp->s_ack_queue[qp->s_tail_ack_queue];
if (e->opcode == OP(RDMA_READ_REQUEST)) {
/* Copy SGE state in case we need to resend */
qp->s_ack_rdma_sge = e->rdma_sge;
qp->s_cur_sge = &qp->s_ack_rdma_sge;
len = e->rdma_sge.sge.sge_length;
if (len > pmtu) {
len = pmtu;
qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
} else
qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
ohdr->u.aeth = ipath_compute_aeth(qp);
hwords++;
qp->s_ack_rdma_psn = e->psn;
bth2 = qp->s_ack_rdma_psn++ & IPATH_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 = ipath_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;
}
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):
len = qp->s_ack_rdma_sge.sge.sge_length;
if (len > pmtu)
len = pmtu;
else {
ohdr->u.aeth = ipath_compute_aeth(qp);
hwords++;
qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
}
bth0 = qp->s_ack_state << 24;
bth2 = qp->s_ack_rdma_psn++ & IPATH_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 &= ~IPATH_S_ACK_PENDING;
qp->s_cur_sge = NULL;
if (qp->s_nak_state)
ohdr->u.aeth =
cpu_to_be32((qp->r_msn & IPATH_MSN_MASK) |
(qp->s_nak_state <<
IPATH_AETH_CREDIT_SHIFT));
else
ohdr->u.aeth = ipath_compute_aeth(qp);
hwords++;
len = 0;
bth0 = OP(ACKNOWLEDGE) << 24;
bth2 = qp->s_ack_psn & IPATH_PSN_MASK;
}
qp->s_hdrwords = hwords;
qp->s_cur_size = len;
*bth0p = bth0;
*bth2p = bth2;
return 1;
bail:
return 0;
}
/**
* ipath_make_rc_req - construct a request packet (SEND, RDMA r/w, ATOMIC)
* @qp: a pointer to the QP
* @ohdr: a pointer to the IB header being constructed
* @pmtu: the path MTU
* @bth0p: pointer to the BTH opcode word
* @bth2p: pointer to the BTH PSN word
*
* Return 1 if constructed; otherwise, return 0.
* Note the QP s_lock must be held and interrupts disabled.
*/
int ipath_make_rc_req(struct ipath_qp *qp,
struct ipath_other_headers *ohdr,
u32 pmtu, u32 *bth0p, u32 *bth2p)
{
struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
struct ipath_sge_state *ss;
struct ipath_swqe *wqe;
u32 hwords;
u32 len;
u32 bth0;
u32 bth2;
char newreq;
/* Sending responses has higher priority over sending requests. */
if ((qp->r_head_ack_queue != qp->s_tail_ack_queue ||
(qp->s_flags & IPATH_S_ACK_PENDING) ||
qp->s_ack_state != OP(ACKNOWLEDGE)) &&
ipath_make_rc_ack(qp, ohdr, pmtu, bth0p, bth2p))
goto done;
if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK) ||
qp->s_rnr_timeout || qp->s_wait_credit)
goto bail;
/* Limit the number of packets sent without an ACK. */
if (ipath_cmp24(qp->s_psn, qp->s_last_psn + IPATH_PSN_CREDIT) > 0) {
qp->s_wait_credit = 1;
dev->n_rc_stalls++;
goto bail;
}
/* 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:
/*
* 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 |= IPATH_S_FENCE_PENDING;
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 = 0;
switch (wqe->wr.opcode) {
case IB_WR_SEND:
case IB_WR_SEND_WITH_IMM:
/* If no credit, return. */
if (qp->s_lsn != (u32) -1 &&
ipath_cmp24(wqe->ssn, qp->s_lsn + 1) > 0)
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.imm_data;
hwords += 1;
}
if (wqe->wr.send_flags & IB_SEND_SOLICITED)
bth0 |= 1 << 23;
bth2 = 1 << 31; /* Request ACK. */
if (++qp->s_cur == qp->s_size)
qp->s_cur = 0;
break;
case IB_WR_RDMA_WRITE:
if (newreq && qp->s_lsn != (u32) -1)
qp->s_lsn++;
/* FALLTHROUGH */
case IB_WR_RDMA_WRITE_WITH_IMM:
/* If no credit, return. */
if (qp->s_lsn != (u32) -1 &&
ipath_cmp24(wqe->ssn, qp->s_lsn + 1) > 0)
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.imm_data;
hwords += 1;
if (wqe->wr.send_flags & IB_SEND_SOLICITED)
bth0 |= 1 << 23;
}
bth2 = 1 << 31; /* Request 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 |= IPATH_S_RDMAR_PENDING;
goto bail;
}
qp->s_num_rd_atomic++;
if (qp->s_lsn != (u32) -1)
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;
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 |= IPATH_S_RDMAR_PENDING;
goto bail;
}
qp->s_num_rd_atomic++;
if (qp->s_lsn != (u32) -1)
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;
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_len = wqe->length;
if (newreq) {
qp->s_tail++;
if (qp->s_tail >= qp->s_size)
qp->s_tail = 0;
}
bth2 |= qp->s_psn & IPATH_PSN_MASK;
if (wqe->wr.opcode == IB_WR_RDMA_READ)
qp->s_psn = wqe->lpsn + 1;
else {
qp->s_psn++;
if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
qp->s_next_psn = qp->s_psn;
}
/*
* Put the QP on the pending list so lost ACKs will cause
* a retry. More than one request can be pending so the
* QP may already be on the dev->pending list.
*/
spin_lock(&dev->pending_lock);
if (list_empty(&qp->timerwait))
list_add_tail(&qp->timerwait,
&dev->pending[dev->pending_index]);
spin_unlock(&dev->pending_lock);
break;
case OP(RDMA_READ_RESPONSE_FIRST):
/*
* This case can only happen if a send is restarted.
* See ipath_restart_rc().
*/
ipath_init_restart(qp, wqe);
/* FALLTHROUGH */
case OP(SEND_FIRST):
qp->s_state = OP(SEND_MIDDLE);
/* FALLTHROUGH */
case OP(SEND_MIDDLE):
bth2 = qp->s_psn++ & IPATH_PSN_MASK;
if (ipath_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.imm_data;
hwords += 1;
}
if (wqe->wr.send_flags & IB_SEND_SOLICITED)
bth0 |= 1 << 23;
bth2 |= 1 << 31; /* Request ACK. */
qp->s_cur++;
if (qp->s_cur >= qp->s_size)
qp->s_cur = 0;
break;
case OP(RDMA_READ_RESPONSE_LAST):
/*
* This case can only happen if a RDMA write is restarted.
* See ipath_restart_rc().
*/
ipath_init_restart(qp, wqe);
/* FALLTHROUGH */
case OP(RDMA_WRITE_FIRST):
qp->s_state = OP(RDMA_WRITE_MIDDLE);
/* FALLTHROUGH */
case OP(RDMA_WRITE_MIDDLE):
bth2 = qp->s_psn++ & IPATH_PSN_MASK;
if (ipath_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.imm_data;
hwords += 1;
if (wqe->wr.send_flags & IB_SEND_SOLICITED)
bth0 |= 1 << 23;
}
bth2 |= 1 << 31; /* Request ACK. */
qp->s_cur++;
if (qp->s_cur >= qp->s_size)
qp->s_cur = 0;
break;
case OP(RDMA_READ_RESPONSE_MIDDLE):
/*
* This case can only happen if a RDMA read is restarted.
* See ipath_restart_rc().
*/
ipath_init_restart(qp, wqe);
len = ((qp->s_psn - wqe->psn) & IPATH_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(qp->s_len);
qp->s_state = OP(RDMA_READ_REQUEST);
hwords += sizeof(ohdr->u.rc.reth) / sizeof(u32);
bth2 = qp->s_psn++ & IPATH_PSN_MASK;
if (ipath_cmp24(qp->s_psn, qp->s_next_psn) > 0)
qp->s_next_psn = qp->s_psn;
ss = NULL;
len = 0;
qp->s_cur++;
if (qp->s_cur == qp->s_size)
qp->s_cur = 0;
break;
}
if (ipath_cmp24(qp->s_psn, qp->s_last_psn + IPATH_PSN_CREDIT - 1) >= 0)
bth2 |= 1 << 31; /* Request ACK. */
qp->s_len -= len;
qp->s_hdrwords = hwords;
qp->s_cur_sge = ss;
qp->s_cur_size = len;
*bth0p = bth0 | (qp->s_state << 24);
*bth2p = bth2;
done:
return 1;
bail:
return 0;
}
/**
* send_rc_ack - Construct an ACK packet and send it
* @qp: a pointer to the QP
*
* This is called from ipath_rc_rcv() and only uses the receive
* side QP state.
* Note that RDMA reads and atomics are handled in the
* send side QP state and tasklet.
*/
static void send_rc_ack(struct ipath_qp *qp)
{
struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
u16 lrh0;
u32 bth0;
u32 hwords;
struct ipath_ib_header hdr;
struct ipath_other_headers *ohdr;
unsigned long flags;
/* Don't send ACK or NAK if a RDMA read or atomic is pending. */
if (qp->r_head_ack_queue != qp->s_tail_ack_queue ||
(qp->s_flags & IPATH_S_ACK_PENDING) ||
qp->s_ack_state != OP(ACKNOWLEDGE))
goto queue_ack;
/* Construct the header. */
ohdr = &hdr.u.oth;
lrh0 = IPATH_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 += ipath_make_grh(dev, &hdr.u.l.grh,
&qp->remote_ah_attr.grh,
hwords, 0);
ohdr = &hdr.u.l.oth;
lrh0 = IPATH_LRH_GRH;
}
/* read pkey_index w/o lock (its atomic) */
bth0 = ipath_get_pkey(dev->dd, qp->s_pkey_index) |
OP(ACKNOWLEDGE) << 24;
if (qp->r_nak_state)
ohdr->u.aeth = cpu_to_be32((qp->r_msn & IPATH_MSN_MASK) |
(qp->r_nak_state <<
IPATH_AETH_CREDIT_SHIFT));
else
ohdr->u.aeth = ipath_compute_aeth(qp);
lrh0 |= 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(dev->dd->ipath_lid);
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 & IPATH_PSN_MASK);
/*
* If we can send the ACK, clear the ACK state.
*/
if (ipath_verbs_send(dev->dd, hwords, (u32 *) &hdr, 0, NULL) == 0) {
dev->n_unicast_xmit++;
goto done;
}
/*
* We are out of PIO buffers at the moment.
* Pass responsibility for sending the ACK to the
* send tasklet so that when a PIO buffer becomes
* available, the ACK is sent ahead of other outgoing
* packets.
*/
dev->n_rc_qacks++;
queue_ack:
spin_lock_irqsave(&qp->s_lock, flags);
qp->s_flags |= IPATH_S_ACK_PENDING;
qp->s_nak_state = qp->r_nak_state;
qp->s_ack_psn = qp->r_ack_psn;
spin_unlock_irqrestore(&qp->s_lock, flags);
/* Call ipath_do_rc_send() in another thread. */
tasklet_hi_schedule(&qp->s_task);
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 ipath_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 ipath_qp *qp, u32 psn)
{
u32 n = qp->s_last;
struct ipath_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 (ipath_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 = ipath_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 ipath_do_rc_send().
*/
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;
}
/**
* ipath_restart_rc - back up requester to resend the last un-ACKed request
* @qp: the QP to restart
* @psn: packet sequence number for the request
* @wc: the work completion request
*
* The QP s_lock should be held and interrupts disabled.
*/
void ipath_restart_rc(struct ipath_qp *qp, u32 psn, struct ib_wc *wc)
{
struct ipath_swqe *wqe = get_swqe_ptr(qp, qp->s_last);
struct ipath_ibdev *dev;
if (qp->s_retry == 0) {
wc->wr_id = wqe->wr.wr_id;
wc->status = IB_WC_RETRY_EXC_ERR;
wc->opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
wc->vendor_err = 0;
wc->byte_len = 0;
wc->qp = &qp->ibqp;
wc->src_qp = qp->remote_qpn;
wc->pkey_index = 0;
wc->slid = qp->remote_ah_attr.dlid;
wc->sl = qp->remote_ah_attr.sl;
wc->dlid_path_bits = 0;
wc->port_num = 0;
ipath_sqerror_qp(qp, wc);
goto bail;
}
qp->s_retry--;
/*
* Remove the QP from the timeout queue.
* Note: it may already have been removed by ipath_ib_timer().
*/
dev = to_idev(qp->ibqp.device);
spin_lock(&dev->pending_lock);
if (!list_empty(&qp->timerwait))
list_del_init(&qp->timerwait);
spin_unlock(&dev->pending_lock);
if (wqe->wr.opcode == IB_WR_RDMA_READ)
dev->n_rc_resends++;
else
dev->n_rc_resends += (qp->s_psn - psn) & IPATH_PSN_MASK;
reset_psn(qp, psn);
tasklet_hi_schedule(&qp->s_task);
bail:
return;
}
static inline void update_last_psn(struct ipath_qp *qp, u32 psn)
{
if (qp->s_wait_credit) {
qp->s_wait_credit = 0;
tasklet_hi_schedule(&qp->s_task);
}
qp->s_last_psn = psn;
}
/**
* 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 ipath_rc_rcv_resp() to process an incoming RC ACK
* for the given QP.
* Called at interrupt level with the QP s_lock held and interrupts disabled.
* Returns 1 if OK, 0 if current operation should be aborted (NAK).
*/
static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode)
{
struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
struct ib_wc wc;
struct ipath_swqe *wqe;
int ret = 0;
u32 ack_psn;
/*
* Remove the QP from the timeout queue (or RNR timeout queue).
* If ipath_ib_timer() has already removed it,
* it's OK since we hold the QP s_lock and ipath_restart_rc()
* just won't find anything to restart if we ACK everything.
*/
spin_lock(&dev->pending_lock);
if (!list_empty(&qp->timerwait))
list_del_init(&qp->timerwait);
spin_unlock(&dev->pending_lock);
/*
* 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_last);
/*
* The MSN might be for a later WQE than the PSN indicates so
* only complete WQEs that the PSN finishes.
*/
while (ipath_cmp24(ack_psn, wqe->lpsn) >= 0) {
/*
* 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) ||
ipath_cmp24(ack_psn, wqe->lpsn) != 0)) ||
((wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP ||
wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) &&
(opcode != OP(ATOMIC_ACKNOWLEDGE) ||
ipath_cmp24(wqe->psn, psn) != 0))) {
/*
* The last valid PSN seen is the previous
* request's.
*/
update_last_psn(qp, wqe->psn - 1);
/* Retry this request. */
ipath_restart_rc(qp, wqe->psn, &wc);
/*
* No need to process the ACK/NAK since we are
* restarting an earlier request.
*/
goto bail;
}
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 & IPATH_S_FENCE_PENDING) &&
!qp->s_num_rd_atomic) {
qp->s_flags &= ~IPATH_S_FENCE_PENDING;
tasklet_hi_schedule(&qp->s_task);
} else if (qp->s_flags & IPATH_S_RDMAR_PENDING) {
qp->s_flags &= ~IPATH_S_RDMAR_PENDING;
tasklet_hi_schedule(&qp->s_task);
}
}
/* Post a send completion queue entry if requested. */
if (!(qp->s_flags & IPATH_S_SIGNAL_REQ_WR) ||
(wqe->wr.send_flags & IB_SEND_SIGNALED)) {
wc.wr_id = wqe->wr.wr_id;
wc.status = IB_WC_SUCCESS;
wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
wc.vendor_err = 0;
wc.byte_len = wqe->length;
wc.imm_data = 0;
wc.qp = &qp->ibqp;
wc.src_qp = qp->remote_qpn;
wc.wc_flags = 0;
wc.pkey_index = 0;
wc.slid = qp->remote_ah_attr.dlid;
wc.sl = qp->remote_ah_attr.sl;
wc.dlid_path_bits = 0;
wc.port_num = 0;
ipath_cq_enter(to_icq(qp->ibqp.send_cq), &wc, 0);
}
qp->s_retry = qp->s_retry_cnt;
/*
* 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_last == qp->s_cur) {
if (++qp->s_cur >= qp->s_size)
qp->s_cur = 0;
qp->s_last = qp->s_cur;
if (qp->s_last == qp->s_tail)
break;
wqe = get_swqe_ptr(qp, qp->s_cur);
qp->s_state = OP(SEND_LAST);
qp->s_psn = wqe->psn;
} else {
if (++qp->s_last >= qp->s_size)
qp->s_last = 0;
if (qp->s_last == qp->s_tail)
break;
wqe = get_swqe_ptr(qp, qp->s_last);
}
}
switch (aeth >> 29) {
case 0: /* ACK */
dev->n_rc_acks++;
/* If this is a partial ACK, reset the retransmit timer. */
if (qp->s_last != qp->s_tail) {
spin_lock(&dev->pending_lock);
list_add_tail(&qp->timerwait,
&dev->pending[dev->pending_index]);
spin_unlock(&dev->pending_lock);
/*
* If we get a partial ACK for a resent operation,
* we can stop resending the earlier packets and
* continue with the next packet the receiver wants.
*/
if (ipath_cmp24(qp->s_psn, psn) <= 0) {
reset_psn(qp, psn + 1);
tasklet_hi_schedule(&qp->s_task);
}
} else if (ipath_cmp24(qp->s_psn, psn) <= 0) {
qp->s_state = OP(SEND_LAST);
qp->s_psn = psn + 1;
}
ipath_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 */
dev->n_rnr_naks++;
if (qp->s_last == qp->s_tail)
goto bail;
if (qp->s_rnr_retry == 0) {
wc.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);
if (wqe->wr.opcode == IB_WR_RDMA_READ)
dev->n_rc_resends++;
else
dev->n_rc_resends +=
(qp->s_psn - psn) & IPATH_PSN_MASK;
reset_psn(qp, psn);
qp->s_rnr_timeout =
ib_ipath_rnr_table[(aeth >> IPATH_AETH_CREDIT_SHIFT) &
IPATH_AETH_CREDIT_MASK];
ipath_insert_rnr_queue(qp);
goto bail;
case 3: /* NAK */
if (qp->s_last == qp->s_tail)
goto bail;
/* The last valid PSN is the previous PSN. */
update_last_psn(qp, psn - 1);
switch ((aeth >> IPATH_AETH_CREDIT_SHIFT) &
IPATH_AETH_CREDIT_MASK) {
case 0: /* PSN sequence error */
dev->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.
*/
ipath_restart_rc(qp, psn, &wc);
break;
case 1: /* Invalid Request */
wc.status = IB_WC_REM_INV_REQ_ERR;
dev->n_other_naks++;
goto class_b;
case 2: /* Remote Access Error */
wc.status = IB_WC_REM_ACCESS_ERR;
dev->n_other_naks++;
goto class_b;
case 3: /* Remote Operation Error */
wc.status = IB_WC_REM_OP_ERR;
dev->n_other_naks++;
class_b:
wc.wr_id = wqe->wr.wr_id;
wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
wc.vendor_err = 0;
wc.byte_len = 0;
wc.qp = &qp->ibqp;
wc.src_qp = qp->remote_qpn;
wc.pkey_index = 0;
wc.slid = qp->remote_ah_attr.dlid;
wc.sl = qp->remote_ah_attr.sl;
wc.dlid_path_bits = 0;
wc.port_num = 0;
ipath_sqerror_qp(qp, &wc);
break;
default:
/* Ignore other reserved NAK error codes */
goto reserved;
}
qp->s_rnr_retry = qp->s_rnr_retry_cnt;
goto bail;
default: /* 2: reserved */
reserved:
/* Ignore reserved NAK codes. */
goto bail;
}
bail:
return ret;
}
/**
* ipath_rc_rcv_resp - process an incoming RC response packet
* @dev: the device 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
* @header_in_data: true if part of the header data is in the data buffer
*
* This is called from ipath_rc_rcv() to process an incoming RC response
* packet for the given QP.
* Called at interrupt level.
*/
static inline void ipath_rc_rcv_resp(struct ipath_ibdev *dev,
struct ipath_other_headers *ohdr,
void *data, u32 tlen,
struct ipath_qp *qp,
u32 opcode,
u32 psn, u32 hdrsize, u32 pmtu,
int header_in_data)
{
struct ipath_swqe *wqe;
unsigned long flags;
struct ib_wc wc;
int diff;
u32 pad;
u32 aeth;
spin_lock_irqsave(&qp->s_lock, flags);
/* Ignore invalid responses. */
if (ipath_cmp24(psn, qp->s_next_psn) >= 0)
goto ack_done;
/* Ignore duplicate responses. */
diff = ipath_cmp24(psn, qp->s_last_psn);
if (unlikely(diff <= 0)) {
/* Update credits for "ghost" ACKs */
if (diff == 0 && opcode == OP(ACKNOWLEDGE)) {
if (!header_in_data)
aeth = be32_to_cpu(ohdr->u.aeth);
else {
aeth = be32_to_cpu(((__be32 *) data)[0]);
data += sizeof(__be32);
}
if ((aeth >> 29) == 0)
ipath_get_credit(qp, aeth);
}
goto ack_done;
}
if (unlikely(qp->s_last == qp->s_tail))
goto ack_done;
wqe = get_swqe_ptr(qp, qp->s_last);
switch (opcode) {
case OP(ACKNOWLEDGE):
case OP(ATOMIC_ACKNOWLEDGE):
case OP(RDMA_READ_RESPONSE_FIRST):
if (!header_in_data)
aeth = be32_to_cpu(ohdr->u.aeth);
else {
aeth = be32_to_cpu(((__be32 *) data)[0]);
data += sizeof(__be32);
}
if (opcode == OP(ATOMIC_ACKNOWLEDGE)) {
u64 val;
if (!header_in_data) {
__be32 *p = ohdr->u.at.atomic_ack_eth;
val = ((u64) be32_to_cpu(p[0]) << 32) |
be32_to_cpu(p[1]);
} else
val = be64_to_cpu(((__be64 *) data)[0]);
*(u64 *) wqe->sg_list[0].vaddr = val;
}
if (!do_rc_ack(qp, aeth, psn, opcode) ||
opcode != OP(RDMA_READ_RESPONSE_FIRST))
goto ack_done;
hdrsize += 4;
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(ipath_cmp24(psn, qp->s_last_psn + 1))) {
dev->n_rdma_seq++;
ipath_restart_rc(qp, qp->s_last_psn + 1, &wc);
goto ack_done;
}
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. */
spin_lock(&dev->pending_lock);
if (qp->s_rnr_timeout == 0 && !list_empty(&qp->timerwait))
list_move_tail(&qp->timerwait,
&dev->pending[dev->pending_index]);
spin_unlock(&dev->pending_lock);
/*
* 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);
ipath_copy_sge(&qp->s_rdma_read_sge, data, pmtu);
goto bail;
case OP(RDMA_READ_RESPONSE_ONLY):
if (unlikely(ipath_cmp24(psn, qp->s_last_psn + 1))) {
dev->n_rdma_seq++;
ipath_restart_rc(qp, qp->s_last_psn + 1, &wc);
goto ack_done;
}
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 >= 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.
*/
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(ipath_cmp24(psn, qp->s_last_psn + 1))) {
dev->n_rdma_seq++;
ipath_restart_rc(qp, qp->s_last_psn + 1, &wc);
goto ack_done;
}
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;
if (!header_in_data)
aeth = be32_to_cpu(ohdr->u.aeth);
else {
aeth = be32_to_cpu(((__be32 *) data)[0]);
data += sizeof(__be32);
}
ipath_copy_sge(&qp->s_rdma_read_sge, data, tlen);
(void) do_rc_ack(qp, aeth, psn, OP(RDMA_READ_RESPONSE_LAST));
goto ack_done;
}
ack_done:
spin_unlock_irqrestore(&qp->s_lock, flags);
goto bail;
ack_op_err:
wc.status = IB_WC_LOC_QP_OP_ERR;
goto ack_err;
ack_len_err:
wc.status = IB_WC_LOC_LEN_ERR;
ack_err:
wc.wr_id = wqe->wr.wr_id;
wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
wc.vendor_err = 0;
wc.byte_len = 0;
wc.imm_data = 0;
wc.qp = &qp->ibqp;
wc.src_qp = qp->remote_qpn;
wc.wc_flags = 0;
wc.pkey_index = 0;
wc.slid = qp->remote_ah_attr.dlid;
wc.sl = qp->remote_ah_attr.sl;
wc.dlid_path_bits = 0;
wc.port_num = 0;
ipath_sqerror_qp(qp, &wc);
spin_unlock_irqrestore(&qp->s_lock, flags);
bail:
return;
}
/**
* ipath_rc_rcv_error - process an incoming duplicate or error RC packet
* @dev: the device this packet came in on
* @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
* @header_in_data: true if part of the header data is in the data buffer
*
* This is called from ipath_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 inline int ipath_rc_rcv_error(struct ipath_ibdev *dev,
struct ipath_other_headers *ohdr,
void *data,
struct ipath_qp *qp,
u32 opcode,
u32 psn,
int diff,
int header_in_data)
{
struct ipath_ack_entry *e;
u8 i, prev;
int old_req;
unsigned long flags;
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) {
qp->r_nak_state = IB_NAK_PSN_ERROR;
/* Use the expected PSN. */
qp->r_ack_psn = qp->r_psn;
goto send_ack;
}
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.
*/
psn &= IPATH_PSN_MASK;
e = NULL;
old_req = 1;
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 = IPATH_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 (ipath_cmp24(psn, e->psn) >= 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,
* or the send tasklet is already backed up to send an
* earlier entry, we can ignore this request.
*/
if (!e || e->opcode != OP(RDMA_READ_REQUEST) || old_req)
goto unlock_done;
/* RETH comes after BTH */
if (!header_in_data)
reth = &ohdr->u.rc.reth;
else {
reth = (struct ib_reth *)data;
data += sizeof(*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) & IPATH_PSN_MASK) *
ib_mtu_enum_to_int(qp->path_mtu);
len = be32_to_cpu(reth->length);
if (unlikely(offset + len > e->rdma_sge.sge.sge_length))
goto unlock_done;
if (len != 0) {
u32 rkey = be32_to_cpu(reth->rkey);
u64 vaddr = be64_to_cpu(reth->vaddr);
int ok;
ok = ipath_rkey_ok(qp, &e->rdma_sge,
len, vaddr, rkey,
IB_ACCESS_REMOTE_READ);
if (unlikely(!ok))
goto unlock_done;
} else {
e->rdma_sge.sg_list = NULL;
e->rdma_sge.num_sge = 0;
e->rdma_sge.sge.mr = NULL;
e->rdma_sge.sge.vaddr = NULL;
e->rdma_sge.sge.length = 0;
e->rdma_sge.sge.sge_length = 0;
}
e->psn = psn;
qp->s_ack_state = OP(ACKNOWLEDGE);
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_ack_state = OP(ACKNOWLEDGE);
qp->s_tail_ack_queue = prev;
break;
}
default:
if (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;
}
/*
* Resend the RDMA read or atomic op which
* ACKs this duplicate request.
*/
qp->s_ack_state = OP(ACKNOWLEDGE);
qp->s_tail_ack_queue = i;
break;
}
qp->r_nak_state = 0;
tasklet_hi_schedule(&qp->s_task);
unlock_done:
spin_unlock_irqrestore(&qp->s_lock, flags);
done:
return 1;
send_ack:
return 0;
}
static void ipath_rc_error(struct ipath_qp *qp, enum ib_wc_status err)
{
unsigned long flags;
spin_lock_irqsave(&qp->s_lock, flags);
qp->state = IB_QPS_ERR;
ipath_error_qp(qp, err);
spin_unlock_irqrestore(&qp->s_lock, flags);
}
/**
* ipath_rc_rcv - process an incoming RC packet
* @dev: the device this packet came in on
* @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 ipath_qp_rcv() to process an incoming RC packet
* for the given QP.
* Called at interrupt level.
*/
void ipath_rc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
int has_grh, void *data, u32 tlen, struct ipath_qp *qp)
{
struct ipath_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;
int header_in_data;
/* Validate the SLID. See Ch. 9.6.1.5 */
if (unlikely(be16_to_cpu(hdr->lrh[3]) != qp->remote_ah_attr.dlid))
goto done;
/* Check for GRH */
if (!has_grh) {
ohdr = &hdr->u.oth;
hdrsize = 8 + 12; /* LRH + BTH */
psn = be32_to_cpu(ohdr->bth[2]);
header_in_data = 0;
} else {
ohdr = &hdr->u.l.oth;
hdrsize = 8 + 40 + 12; /* LRH + GRH + BTH */
/*
* The header with GRH is 60 bytes and the core driver sets
* the eager header buffer size to 56 bytes so the last 4
* bytes of the BTH header (PSN) is in the data buffer.
*/
header_in_data = dev->dd->ipath_rcvhdrentsize == 16;
if (header_in_data) {
psn = be32_to_cpu(((__be32 *) data)[0]);
data += sizeof(__be32);
} else
psn = be32_to_cpu(ohdr->bth[2]);
}
/*
* 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.
*/
opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
if (opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&
opcode <= OP(ATOMIC_ACKNOWLEDGE)) {
ipath_rc_rcv_resp(dev, ohdr, data, tlen, qp, opcode, psn,
hdrsize, pmtu, header_in_data);
goto done;
}
/* Compute 24 bits worth of difference. */
diff = ipath_cmp24(psn, qp->r_psn);
if (unlikely(diff)) {
if (ipath_rc_rcv_error(dev, ohdr, data, qp, opcode,
psn, diff, header_in_data))
goto done;
goto 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;
nack_inv:
ipath_rc_error(qp, IB_WC_REM_INV_REQ_ERR);
qp->r_nak_state = IB_NAK_INVALID_REQUEST;
qp->r_ack_psn = qp->r_psn;
goto send_ack;
case OP(RDMA_WRITE_FIRST):
case OP(RDMA_WRITE_MIDDLE):
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;
}
wc.imm_data = 0;
wc.wc_flags = 0;
/* OK, process the packet. */
switch (opcode) {
case OP(SEND_FIRST):
if (!ipath_get_rwqe(qp, 0)) {
rnr_nak:
/*
* A RNR NAK will ACK earlier sends and RDMA writes.
* Don't queue the NAK if a RDMA read or atomic
* is pending though.
*/
if (qp->r_nak_state)
goto done;
qp->r_nak_state = IB_RNR_NAK | qp->r_min_rnr_timer;
qp->r_ack_psn = qp->r_psn;
goto send_ack;
}
qp->r_rcv_len = 0;
/* FALLTHROUGH */
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;
ipath_copy_sge(&qp->r_sge, data, pmtu);
break;
case OP(RDMA_WRITE_LAST_WITH_IMMEDIATE):
/* consume RWQE */
if (!ipath_get_rwqe(qp, 1))
goto rnr_nak;
goto send_last_imm;
case OP(SEND_ONLY):
case OP(SEND_ONLY_WITH_IMMEDIATE):
if (!ipath_get_rwqe(qp, 0))
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:
if (header_in_data) {
wc.imm_data = *(__be32 *) data;
data += sizeof(__be32);
} else {
/* Immediate data comes after BTH */
wc.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;
ipath_copy_sge(&qp->r_sge, data, tlen);
qp->r_msn++;
if (!qp->r_wrid_valid)
break;
qp->r_wrid_valid = 0;
wc.wr_id = qp->r_wr_id;
wc.status = IB_WC_SUCCESS;
wc.opcode = IB_WC_RECV;
wc.vendor_err = 0;
wc.qp = &qp->ibqp;
wc.src_qp = qp->remote_qpn;
wc.pkey_index = 0;
wc.slid = qp->remote_ah_attr.dlid;
wc.sl = qp->remote_ah_attr.sl;
wc.dlid_path_bits = 0;
wc.port_num = 0;
/* Signal completion event if the solicited bit is set. */
ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
(ohdr->bth[0] &
__constant_cpu_to_be32(1 << 23)) != 0);
break;
case OP(RDMA_WRITE_FIRST):
case OP(RDMA_WRITE_ONLY):
case OP(RDMA_WRITE_ONLY_WITH_IMMEDIATE):
/* consume RWQE */
/* RETH comes after BTH */
if (!header_in_data)
reth = &ohdr->u.rc.reth;
else {
reth = (struct ib_reth *)data;
data += sizeof(*reth);
}
hdrsize += sizeof(*reth);
qp->r_len = be32_to_cpu(reth->length);
qp->r_rcv_len = 0;
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 = ipath_rkey_ok(qp, &qp->r_sge,
qp->r_len, vaddr, rkey,
IB_ACCESS_REMOTE_WRITE);
if (unlikely(!ok))
goto nack_acc;
} else {
qp->r_sge.sg_list = NULL;
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 (unlikely(!(qp->qp_access_flags &
IB_ACCESS_REMOTE_WRITE)))
goto nack_acc;
if (opcode == OP(RDMA_WRITE_FIRST))
goto send_middle;
else if (opcode == OP(RDMA_WRITE_ONLY))
goto send_last;
if (!ipath_get_rwqe(qp, 1))
goto rnr_nak;
goto send_last_imm;
case OP(RDMA_READ_REQUEST): {
struct ipath_ack_entry *e;
u32 len;
u8 next;
if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
goto nack_acc;
next = qp->r_head_ack_queue + 1;
if (next > IPATH_MAX_RDMA_ATOMIC)
next = 0;
if (unlikely(next == qp->s_tail_ack_queue))
goto nack_inv;
e = &qp->s_ack_queue[qp->r_head_ack_queue];
/* RETH comes after BTH */
if (!header_in_data)
reth = &ohdr->u.rc.reth;
else {
reth = (struct ib_reth *)data;
data += sizeof(*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 = ipath_rkey_ok(qp, &e->rdma_sge, len, vaddr,
rkey, IB_ACCESS_REMOTE_READ);
if (unlikely(!ok))
goto nack_acc;
/*
* 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.sg_list = NULL;
e->rdma_sge.num_sge = 0;
e->rdma_sge.sge.mr = NULL;
e->rdma_sge.sge.vaddr = NULL;
e->rdma_sge.sge.length = 0;
e->rdma_sge.sge.sge_length = 0;
}
e->opcode = opcode;
e->psn = 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;
barrier();
qp->r_head_ack_queue = next;
/* Call ipath_do_rc_send() in another thread. */
tasklet_hi_schedule(&qp->s_task);
goto done;
}
case OP(COMPARE_SWAP):
case OP(FETCH_ADD): {
struct ib_atomic_eth *ateth;
struct ipath_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_acc;
next = qp->r_head_ack_queue + 1;
if (next > IPATH_MAX_RDMA_ATOMIC)
next = 0;
if (unlikely(next == qp->s_tail_ack_queue))
goto nack_inv;
if (!header_in_data)
ateth = &ohdr->u.atomic_eth;
else
ateth = (struct ib_atomic_eth *)data;
vaddr = ((u64) be32_to_cpu(ateth->vaddr[0]) << 32) |
be32_to_cpu(ateth->vaddr[1]);
if (unlikely(vaddr & (sizeof(u64) - 1)))
goto nack_inv;
rkey = be32_to_cpu(ateth->rkey);
/* Check rkey & NAK */
if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge,
sizeof(u64), vaddr, rkey,
IB_ACCESS_REMOTE_ATOMIC)))
goto nack_acc;
/* Perform atomic OP and save result. */
maddr = (atomic64_t *) qp->r_sge.sge.vaddr;
sdata = be64_to_cpu(ateth->swap_data);
e = &qp->s_ack_queue[qp->r_head_ack_queue];
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);
e->opcode = opcode;
e->psn = psn & IPATH_PSN_MASK;
qp->r_msn++;
qp->r_psn++;
qp->r_state = opcode;
qp->r_nak_state = 0;
barrier();
qp->r_head_ack_queue = next;
/* Call ipath_do_rc_send() in another thread. */
tasklet_hi_schedule(&qp->s_task);
goto done;
}
default:
/* NAK unknown opcodes. */
goto nack_inv;
}
qp->r_psn++;
qp->r_state = opcode;
qp->r_ack_psn = psn;
qp->r_nak_state = 0;
/* Send an ACK if requested or required. */
if (psn & (1 << 31))
goto send_ack;
goto done;
nack_acc:
ipath_rc_error(qp, IB_WC_REM_ACCESS_ERR);
qp->r_nak_state = IB_NAK_REMOTE_ACCESS_ERROR;
qp->r_ack_psn = qp->r_psn;
send_ack:
send_rc_ack(qp);
done:
return;
}
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