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android_kernel_samsung_msm8976/drivers/infiniband/hw/ipath/ipath_ruc.c
Michael S. Tsirkin 062dbb69f3 IB: Return qp pointer as part of ib_wc 
struct ib_wc currently only includes the local QP number: this matches
the IB spec, but seems mostly useless. The following patch replaces
this with the pointer to qp itself, and updates all low level drivers
and all users.

This has the following advantages:
- Ability to get a per-qp context through wc->qp->qp_context
- Existing drivers already have the qp pointer ready in poll cq, so
  this change actually saves a tiny bit (extra memory read) on data path
  (for ehca it would actually be expensive to find the QP pointer when
  polling a CQ, but ehca does not support SRQ so we can leave wc->qp as
  NULL for ehca)
- Users that need the QP number can still get it through wc->qp->qp_num

Use case:

In IPoIB connected mode code, I have a common CQ shared by multiple
QPs.  To track connection usage, I need a way to get at some per-QP
context upon the completion, and I would like to avoid allocating
context object per work request just to stick a QP pointer into it.
With this code, I can just use wc->qp->qp_context.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2007-02-04 14:11:55 -08:00

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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"
/*
* Convert the AETH RNR timeout code into the number of milliseconds.
*/
const u32 ib_ipath_rnr_table[32] = {
656, /* 0 */
1, /* 1 */
1, /* 2 */
1, /* 3 */
1, /* 4 */
1, /* 5 */
1, /* 6 */
1, /* 7 */
1, /* 8 */
1, /* 9 */
1, /* A */
1, /* B */
1, /* C */
1, /* D */
2, /* E */
2, /* F */
3, /* 10 */
4, /* 11 */
6, /* 12 */
8, /* 13 */
11, /* 14 */
16, /* 15 */
21, /* 16 */
31, /* 17 */
41, /* 18 */
62, /* 19 */
82, /* 1A */
123, /* 1B */
164, /* 1C */
246, /* 1D */
328, /* 1E */
492 /* 1F */
};
/**
* ipath_insert_rnr_queue - put QP on the RNR timeout list for the device
* @qp: the QP
*
* XXX Use a simple list for now. We might need a priority
* queue if we have lots of QPs waiting for RNR timeouts
* but that should be rare.
*/
void ipath_insert_rnr_queue(struct ipath_qp *qp)
{
struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
unsigned long flags;
spin_lock_irqsave(&dev->pending_lock, flags);
if (list_empty(&dev->rnrwait))
list_add(&qp->timerwait, &dev->rnrwait);
else {
struct list_head *l = &dev->rnrwait;
struct ipath_qp *nqp = list_entry(l->next, struct ipath_qp,
timerwait);
while (qp->s_rnr_timeout >= nqp->s_rnr_timeout) {
qp->s_rnr_timeout -= nqp->s_rnr_timeout;
l = l->next;
if (l->next == &dev->rnrwait)
break;
nqp = list_entry(l->next, struct ipath_qp,
timerwait);
}
list_add(&qp->timerwait, l);
}
spin_unlock_irqrestore(&dev->pending_lock, flags);
}
static int init_sge(struct ipath_qp *qp, struct ipath_rwqe *wqe)
{
int user = to_ipd(qp->ibqp.pd)->user;
int i, j, ret;
struct ib_wc wc;
qp->r_len = 0;
for (i = j = 0; i < wqe->num_sge; i++) {
if (wqe->sg_list[i].length == 0)
continue;
/* Check LKEY */
if ((user && wqe->sg_list[i].lkey == 0) ||
!ipath_lkey_ok(qp, &qp->r_sg_list[j], &wqe->sg_list[i],
IB_ACCESS_LOCAL_WRITE))
goto bad_lkey;
qp->r_len += wqe->sg_list[i].length;
j++;
}
qp->r_sge.sge = qp->r_sg_list[0];
qp->r_sge.sg_list = qp->r_sg_list + 1;
qp->r_sge.num_sge = j;
ret = 1;
goto bail;
bad_lkey:
wc.wr_id = wqe->wr_id;
wc.status = IB_WC_LOC_PROT_ERR;
wc.opcode = IB_WC_RECV;
wc.vendor_err = 0;
wc.byte_len = 0;
wc.imm_data = 0;
wc.qp = &qp->ibqp;
wc.src_qp = 0;
wc.wc_flags = 0;
wc.pkey_index = 0;
wc.slid = 0;
wc.sl = 0;
wc.dlid_path_bits = 0;
wc.port_num = 0;
/* Signal solicited completion event. */
ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc, 1);
ret = 0;
bail:
return ret;
}
/**
* ipath_get_rwqe - copy the next RWQE into the QP's RWQE
* @qp: the QP
* @wr_id_only: update wr_id only, not SGEs
*
* Return 0 if no RWQE is available, otherwise return 1.
*
* Can be called from interrupt level.
*/
int ipath_get_rwqe(struct ipath_qp *qp, int wr_id_only)
{
unsigned long flags;
struct ipath_rq *rq;
struct ipath_rwq *wq;
struct ipath_srq *srq;
struct ipath_rwqe *wqe;
void (*handler)(struct ib_event *, void *);
u32 tail;
int ret;
if (qp->ibqp.srq) {
srq = to_isrq(qp->ibqp.srq);
handler = srq->ibsrq.event_handler;
rq = &srq->rq;
} else {
srq = NULL;
handler = NULL;
rq = &qp->r_rq;
}
spin_lock_irqsave(&rq->lock, flags);
wq = rq->wq;
tail = wq->tail;
/* Validate tail before using it since it is user writable. */
if (tail >= rq->size)
tail = 0;
do {
if (unlikely(tail == wq->head)) {
spin_unlock_irqrestore(&rq->lock, flags);
ret = 0;
goto bail;
}
wqe = get_rwqe_ptr(rq, tail);
if (++tail >= rq->size)
tail = 0;
} while (!wr_id_only && !init_sge(qp, wqe));
qp->r_wr_id = wqe->wr_id;
wq->tail = tail;
ret = 1;
if (handler) {
u32 n;
/*
* validate head pointer value and compute
* the number of remaining WQEs.
*/
n = wq->head;
if (n >= rq->size)
n = 0;
if (n < tail)
n += rq->size - tail;
else
n -= tail;
if (n < srq->limit) {
struct ib_event ev;
srq->limit = 0;
spin_unlock_irqrestore(&rq->lock, flags);
ev.device = qp->ibqp.device;
ev.element.srq = qp->ibqp.srq;
ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
handler(&ev, srq->ibsrq.srq_context);
goto bail;
}
}
spin_unlock_irqrestore(&rq->lock, flags);
qp->r_wrid_valid = 1;
bail:
return ret;
}
/**
* ipath_ruc_loopback - handle UC and RC lookback requests
* @sqp: the loopback QP
*
* This is called from ipath_do_uc_send() or ipath_do_rc_send() to
* forward a WQE addressed to the same HCA.
* Note that although we are single threaded due to the tasklet, we still
* have to protect against post_send(). We don't have to worry about
* receive interrupts since this is a connected protocol and all packets
* will pass through here.
*/
static void ipath_ruc_loopback(struct ipath_qp *sqp)
{
struct ipath_ibdev *dev = to_idev(sqp->ibqp.device);
struct ipath_qp *qp;
struct ipath_swqe *wqe;
struct ipath_sge *sge;
unsigned long flags;
struct ib_wc wc;
u64 sdata;
qp = ipath_lookup_qpn(&dev->qp_table, sqp->remote_qpn);
if (!qp) {
dev->n_pkt_drops++;
return;
}
again:
spin_lock_irqsave(&sqp->s_lock, flags);
if (!(ib_ipath_state_ops[sqp->state] & IPATH_PROCESS_SEND_OK)) {
spin_unlock_irqrestore(&sqp->s_lock, flags);
goto done;
}
/* Get the next send request. */
if (sqp->s_last == sqp->s_head) {
/* Send work queue is empty. */
spin_unlock_irqrestore(&sqp->s_lock, flags);
goto done;
}
/*
* We can rely on the entry not changing without the s_lock
* being held until we update s_last.
*/
wqe = get_swqe_ptr(sqp, sqp->s_last);
spin_unlock_irqrestore(&sqp->s_lock, flags);
wc.wc_flags = 0;
wc.imm_data = 0;
sqp->s_sge.sge = wqe->sg_list[0];
sqp->s_sge.sg_list = wqe->sg_list + 1;
sqp->s_sge.num_sge = wqe->wr.num_sge;
sqp->s_len = wqe->length;
switch (wqe->wr.opcode) {
case IB_WR_SEND_WITH_IMM:
wc.wc_flags = IB_WC_WITH_IMM;
wc.imm_data = wqe->wr.imm_data;
/* FALLTHROUGH */
case IB_WR_SEND:
if (!ipath_get_rwqe(qp, 0)) {
rnr_nak:
/* Handle RNR NAK */
if (qp->ibqp.qp_type == IB_QPT_UC)
goto send_comp;
if (sqp->s_rnr_retry == 0) {
wc.status = IB_WC_RNR_RETRY_EXC_ERR;
goto err;
}
if (sqp->s_rnr_retry_cnt < 7)
sqp->s_rnr_retry--;
dev->n_rnr_naks++;
sqp->s_rnr_timeout =
ib_ipath_rnr_table[sqp->r_min_rnr_timer];
ipath_insert_rnr_queue(sqp);
goto done;
}
break;
case IB_WR_RDMA_WRITE_WITH_IMM:
wc.wc_flags = IB_WC_WITH_IMM;
wc.imm_data = wqe->wr.imm_data;
if (!ipath_get_rwqe(qp, 1))
goto rnr_nak;
/* FALLTHROUGH */
case IB_WR_RDMA_WRITE:
if (wqe->length == 0)
break;
if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge, wqe->length,
wqe->wr.wr.rdma.remote_addr,
wqe->wr.wr.rdma.rkey,
IB_ACCESS_REMOTE_WRITE))) {
acc_err:
wc.status = IB_WC_REM_ACCESS_ERR;
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.qp = &sqp->ibqp;
wc.src_qp = sqp->remote_qpn;
wc.pkey_index = 0;
wc.slid = sqp->remote_ah_attr.dlid;
wc.sl = sqp->remote_ah_attr.sl;
wc.dlid_path_bits = 0;
wc.port_num = 0;
ipath_sqerror_qp(sqp, &wc);
goto done;
}
break;
case IB_WR_RDMA_READ:
if (unlikely(!ipath_rkey_ok(qp, &sqp->s_sge, wqe->length,
wqe->wr.wr.rdma.remote_addr,
wqe->wr.wr.rdma.rkey,
IB_ACCESS_REMOTE_READ)))
goto acc_err;
if (unlikely(!(qp->qp_access_flags &
IB_ACCESS_REMOTE_READ)))
goto acc_err;
qp->r_sge.sge = wqe->sg_list[0];
qp->r_sge.sg_list = wqe->sg_list + 1;
qp->r_sge.num_sge = wqe->wr.num_sge;
break;
case IB_WR_ATOMIC_CMP_AND_SWP:
case IB_WR_ATOMIC_FETCH_AND_ADD:
if (unlikely(!ipath_rkey_ok(qp, &qp->r_sge, sizeof(u64),
wqe->wr.wr.rdma.remote_addr,
wqe->wr.wr.rdma.rkey,
IB_ACCESS_REMOTE_ATOMIC)))
goto acc_err;
/* Perform atomic OP and save result. */
sdata = wqe->wr.wr.atomic.swap;
spin_lock_irqsave(&dev->pending_lock, flags);
qp->r_atomic_data = *(u64 *) qp->r_sge.sge.vaddr;
if (wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD)
*(u64 *) qp->r_sge.sge.vaddr =
qp->r_atomic_data + sdata;
else if (qp->r_atomic_data == wqe->wr.wr.atomic.compare_add)
*(u64 *) qp->r_sge.sge.vaddr = sdata;
spin_unlock_irqrestore(&dev->pending_lock, flags);
*(u64 *) sqp->s_sge.sge.vaddr = qp->r_atomic_data;
goto send_comp;
default:
goto done;
}
sge = &sqp->s_sge.sge;
while (sqp->s_len) {
u32 len = sqp->s_len;
if (len > sge->length)
len = sge->length;
BUG_ON(len == 0);
ipath_copy_sge(&qp->r_sge, sge->vaddr, len);
sge->vaddr += len;
sge->length -= len;
sge->sge_length -= len;
if (sge->sge_length == 0) {
if (--sqp->s_sge.num_sge)
*sge = *sqp->s_sge.sg_list++;
} else if (sge->length == 0 && sge->mr != NULL) {
if (++sge->n >= IPATH_SEGSZ) {
if (++sge->m >= sge->mr->mapsz)
break;
sge->n = 0;
}
sge->vaddr =
sge->mr->map[sge->m]->segs[sge->n].vaddr;
sge->length =
sge->mr->map[sge->m]->segs[sge->n].length;
}
sqp->s_len -= len;
}
if (wqe->wr.opcode == IB_WR_RDMA_WRITE ||
wqe->wr.opcode == IB_WR_RDMA_READ)
goto send_comp;
if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM)
wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
else
wc.opcode = IB_WC_RECV;
wc.wr_id = qp->r_wr_id;
wc.status = IB_WC_SUCCESS;
wc.vendor_err = 0;
wc.byte_len = wqe->length;
wc.qp = &qp->ibqp;
wc.src_qp = qp->remote_qpn;
/* XXX do we know which pkey matched? Only needed for GSI. */
wc.pkey_index = 0;
wc.slid = qp->remote_ah_attr.dlid;
wc.sl = qp->remote_ah_attr.sl;
wc.dlid_path_bits = 0;
/* Signal completion event if the solicited bit is set. */
ipath_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
wqe->wr.send_flags & IB_SEND_SOLICITED);
send_comp:
sqp->s_rnr_retry = sqp->s_rnr_retry_cnt;
if (!test_bit(IPATH_S_SIGNAL_REQ_WR, &sqp->s_flags) ||
(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.qp = &sqp->ibqp;
wc.src_qp = 0;
wc.pkey_index = 0;
wc.slid = 0;
wc.sl = 0;
wc.dlid_path_bits = 0;
wc.port_num = 0;
ipath_cq_enter(to_icq(sqp->ibqp.send_cq), &wc, 0);
}
/* Update s_last now that we are finished with the SWQE */
spin_lock_irqsave(&sqp->s_lock, flags);
if (++sqp->s_last >= sqp->s_size)
sqp->s_last = 0;
spin_unlock_irqrestore(&sqp->s_lock, flags);
goto again;
done:
if (atomic_dec_and_test(&qp->refcount))
wake_up(&qp->wait);
}
static int want_buffer(struct ipath_devdata *dd)
{
set_bit(IPATH_S_PIOINTBUFAVAIL, &dd->ipath_sendctrl);
ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
dd->ipath_sendctrl);
return 0;
}
/**
* ipath_no_bufs_available - tell the layer driver we need buffers
* @qp: the QP that caused the problem
* @dev: the device we ran out of buffers on
*
* Called when we run out of PIO buffers.
*/
void ipath_no_bufs_available(struct ipath_qp *qp, struct ipath_ibdev *dev)
{
unsigned long flags;
spin_lock_irqsave(&dev->pending_lock, flags);
if (list_empty(&qp->piowait))
list_add_tail(&qp->piowait, &dev->piowait);
spin_unlock_irqrestore(&dev->pending_lock, flags);
/*
* Note that as soon as want_buffer() is called and
* possibly before it returns, ipath_ib_piobufavail()
* could be called. If we are still in the tasklet function,
* tasklet_hi_schedule() will not call us until the next time
* tasklet_hi_schedule() is called.
* We clear the tasklet flag now since we are committing to return
* from the tasklet function.
*/
clear_bit(IPATH_S_BUSY, &qp->s_flags);
tasklet_unlock(&qp->s_task);
want_buffer(dev->dd);
dev->n_piowait++;
}
/**
* ipath_post_ruc_send - post RC and UC sends
* @qp: the QP to post on
* @wr: the work request to send
*/
int ipath_post_ruc_send(struct ipath_qp *qp, struct ib_send_wr *wr)
{
struct ipath_swqe *wqe;
unsigned long flags;
u32 next;
int i, j;
int acc;
int ret;
/*
* Don't allow RDMA reads or atomic operations on UC or
* undefined operations.
* Make sure buffer is large enough to hold the result for atomics.
*/
if (qp->ibqp.qp_type == IB_QPT_UC) {
if ((unsigned) wr->opcode >= IB_WR_RDMA_READ) {
ret = -EINVAL;
goto bail;
}
} else if ((unsigned) wr->opcode > IB_WR_ATOMIC_FETCH_AND_ADD) {
ret = -EINVAL;
goto bail;
} else if (wr->opcode >= IB_WR_ATOMIC_CMP_AND_SWP &&
(wr->num_sge == 0 ||
wr->sg_list[0].length < sizeof(u64) ||
wr->sg_list[0].addr & (sizeof(u64) - 1))) {
ret = -EINVAL;
goto bail;
}
/* IB spec says that num_sge == 0 is OK. */
if (wr->num_sge > qp->s_max_sge) {
ret = -ENOMEM;
goto bail;
}
spin_lock_irqsave(&qp->s_lock, flags);
next = qp->s_head + 1;
if (next >= qp->s_size)
next = 0;
if (next == qp->s_last) {
spin_unlock_irqrestore(&qp->s_lock, flags);
ret = -EINVAL;
goto bail;
}
wqe = get_swqe_ptr(qp, qp->s_head);
wqe->wr = *wr;
wqe->ssn = qp->s_ssn++;
wqe->sg_list[0].mr = NULL;
wqe->sg_list[0].vaddr = NULL;
wqe->sg_list[0].length = 0;
wqe->sg_list[0].sge_length = 0;
wqe->length = 0;
acc = wr->opcode >= IB_WR_RDMA_READ ? IB_ACCESS_LOCAL_WRITE : 0;
for (i = 0, j = 0; i < wr->num_sge; i++) {
if (to_ipd(qp->ibqp.pd)->user && wr->sg_list[i].lkey == 0) {
spin_unlock_irqrestore(&qp->s_lock, flags);
ret = -EINVAL;
goto bail;
}
if (wr->sg_list[i].length == 0)
continue;
if (!ipath_lkey_ok(qp, &wqe->sg_list[j], &wr->sg_list[i],
acc)) {
spin_unlock_irqrestore(&qp->s_lock, flags);
ret = -EINVAL;
goto bail;
}
wqe->length += wr->sg_list[i].length;
j++;
}
wqe->wr.num_sge = j;
qp->s_head = next;
spin_unlock_irqrestore(&qp->s_lock, flags);
ipath_do_ruc_send((unsigned long) qp);
ret = 0;
bail:
return ret;
}
/**
* ipath_make_grh - construct a GRH header
* @dev: a pointer to the ipath device
* @hdr: a pointer to the GRH header being constructed
* @grh: the global route address to send to
* @hwords: the number of 32 bit words of header being sent
* @nwords: the number of 32 bit words of data being sent
*
* Return the size of the header in 32 bit words.
*/
u32 ipath_make_grh(struct ipath_ibdev *dev, struct ib_grh *hdr,
struct ib_global_route *grh, u32 hwords, u32 nwords)
{
hdr->version_tclass_flow =
cpu_to_be32((6 << 28) |
(grh->traffic_class << 20) |
grh->flow_label);
hdr->paylen = cpu_to_be16((hwords - 2 + nwords + SIZE_OF_CRC) << 2);
/* next_hdr is defined by C8-7 in ch. 8.4.1 */
hdr->next_hdr = 0x1B;
hdr->hop_limit = grh->hop_limit;
/* The SGID is 32-bit aligned. */
hdr->sgid.global.subnet_prefix = dev->gid_prefix;
hdr->sgid.global.interface_id = dev->dd->ipath_guid;
hdr->dgid = grh->dgid;
/* GRH header size in 32-bit words. */
return sizeof(struct ib_grh) / sizeof(u32);
}
/**
* ipath_do_ruc_send - perform a send on an RC or UC QP
* @data: contains a pointer to the QP
*
* Process entries in the send work queue until credit or queue is
* exhausted. Only allow one CPU to send a packet per QP (tasklet).
* Otherwise, after we drop the QP s_lock, two threads could send
* packets out of order.
*/
void ipath_do_ruc_send(unsigned long data)
{
struct ipath_qp *qp = (struct ipath_qp *)data;
struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
unsigned long flags;
u16 lrh0;
u32 nwords;
u32 extra_bytes;
u32 bth0;
u32 bth2;
u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
struct ipath_other_headers *ohdr;
if (test_and_set_bit(IPATH_S_BUSY, &qp->s_flags))
goto bail;
if (unlikely(qp->remote_ah_attr.dlid == dev->dd->ipath_lid)) {
ipath_ruc_loopback(qp);
goto clear;
}
ohdr = &qp->s_hdr.u.oth;
if (qp->remote_ah_attr.ah_flags & IB_AH_GRH)
ohdr = &qp->s_hdr.u.l.oth;
again:
/* Check for a constructed packet to be sent. */
if (qp->s_hdrwords != 0) {
/*
* If no PIO bufs are available, return. An interrupt will
* call ipath_ib_piobufavail() when one is available.
*/
if (ipath_verbs_send(dev->dd, qp->s_hdrwords,
(u32 *) &qp->s_hdr, qp->s_cur_size,
qp->s_cur_sge)) {
ipath_no_bufs_available(qp, dev);
goto bail;
}
dev->n_unicast_xmit++;
/* Record that we sent the packet and s_hdr is empty. */
qp->s_hdrwords = 0;
}
/*
* The lock is needed to synchronize between setting
* qp->s_ack_state, resend timer, and post_send().
*/
spin_lock_irqsave(&qp->s_lock, flags);
/* Sending responses has higher priority over sending requests. */
if (qp->s_ack_state != IB_OPCODE_RC_ACKNOWLEDGE &&
(bth0 = ipath_make_rc_ack(qp, ohdr, pmtu)) != 0)
bth2 = qp->s_ack_psn++ & IPATH_PSN_MASK;
else if (!((qp->ibqp.qp_type == IB_QPT_RC) ?
ipath_make_rc_req(qp, ohdr, pmtu, &bth0, &bth2) :
ipath_make_uc_req(qp, ohdr, pmtu, &bth0, &bth2))) {
/*
* Clear the busy bit before unlocking to avoid races with
* adding new work queue items and then failing to process
* them.
*/
clear_bit(IPATH_S_BUSY, &qp->s_flags);
spin_unlock_irqrestore(&qp->s_lock, flags);
goto bail;
}
spin_unlock_irqrestore(&qp->s_lock, flags);
/* Construct the header. */
extra_bytes = (4 - qp->s_cur_size) & 3;
nwords = (qp->s_cur_size + extra_bytes) >> 2;
lrh0 = IPATH_LRH_BTH;
if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
qp->s_hdrwords += ipath_make_grh(dev, &qp->s_hdr.u.l.grh,
&qp->remote_ah_attr.grh,
qp->s_hdrwords, nwords);
lrh0 = IPATH_LRH_GRH;
}
lrh0 |= qp->remote_ah_attr.sl << 4;
qp->s_hdr.lrh[0] = cpu_to_be16(lrh0);
qp->s_hdr.lrh[1] = cpu_to_be16(qp->remote_ah_attr.dlid);
qp->s_hdr.lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords +
SIZE_OF_CRC);
qp->s_hdr.lrh[3] = cpu_to_be16(dev->dd->ipath_lid);
bth0 |= ipath_get_pkey(dev->dd, qp->s_pkey_index);
bth0 |= extra_bytes << 20;
ohdr->bth[0] = cpu_to_be32(bth0);
ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
ohdr->bth[2] = cpu_to_be32(bth2);
/* Check for more work to do. */
goto again;
clear:
clear_bit(IPATH_S_BUSY, &qp->s_flags);
bail:
return;
}
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