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kernel-ark/drivers/infiniband/hw/qib/qib_ud.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

584 lines
16 KiB
C
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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 <rdma/ib_smi.h>
#include "qib.h"
#include "qib_mad.h"
/**
* qib_ud_loopback - handle send on loopback QPs
* @sqp: the sending QP
* @swqe: the send work request
*
* This is called from qib_make_ud_req() to forward a WQE addressed
* to the same HCA.
* Note that the receive interrupt handler may be calling qib_ud_rcv()
* while this is being called.
*/
static void qib_ud_loopback(struct qib_qp *sqp, struct qib_swqe *swqe)
{
struct qib_ibport *ibp = to_iport(sqp->ibqp.device, sqp->port_num);
struct qib_pportdata *ppd;
struct qib_qp *qp;
struct ib_ah_attr *ah_attr;
unsigned long flags;
struct qib_sge_state ssge;
struct qib_sge *sge;
struct ib_wc wc;
u32 length;
qp = qib_lookup_qpn(ibp, swqe->wr.wr.ud.remote_qpn);
if (!qp) {
ibp->n_pkt_drops++;
return;
}
if (qp->ibqp.qp_type != sqp->ibqp.qp_type ||
!(ib_qib_state_ops[qp->state] & QIB_PROCESS_RECV_OK)) {
ibp->n_pkt_drops++;
goto drop;
}
ah_attr = &to_iah(swqe->wr.wr.ud.ah)->attr;
ppd = ppd_from_ibp(ibp);
if (qp->ibqp.qp_num > 1) {
u16 pkey1;
u16 pkey2;
u16 lid;
pkey1 = qib_get_pkey(ibp, sqp->s_pkey_index);
pkey2 = qib_get_pkey(ibp, qp->s_pkey_index);
if (unlikely(!qib_pkey_ok(pkey1, pkey2))) {
lid = ppd->lid | (ah_attr->src_path_bits &
((1 << ppd->lmc) - 1));
qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_PKEY, pkey1,
ah_attr->sl,
sqp->ibqp.qp_num, qp->ibqp.qp_num,
cpu_to_be16(lid),
cpu_to_be16(ah_attr->dlid));
goto drop;
}
}
/*
* Check that the qkey matches (except for QP0, see 9.6.1.4.1).
* Qkeys with the high order bit set mean use the
* qkey from the QP context instead of the WR (see 10.2.5).
*/
if (qp->ibqp.qp_num) {
u32 qkey;
qkey = (int)swqe->wr.wr.ud.remote_qkey < 0 ?
sqp->qkey : swqe->wr.wr.ud.remote_qkey;
if (unlikely(qkey != qp->qkey)) {
u16 lid;
lid = ppd->lid | (ah_attr->src_path_bits &
((1 << ppd->lmc) - 1));
qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_QKEY, qkey,
ah_attr->sl,
sqp->ibqp.qp_num, qp->ibqp.qp_num,
cpu_to_be16(lid),
cpu_to_be16(ah_attr->dlid));
goto drop;
}
}
/*
* A GRH is expected to precede the data even if not
* present on the wire.
*/
length = swqe->length;
memset(&wc, 0, sizeof wc);
wc.byte_len = length + sizeof(struct ib_grh);
if (swqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
wc.wc_flags = IB_WC_WITH_IMM;
wc.ex.imm_data = swqe->wr.ex.imm_data;
}
spin_lock_irqsave(&qp->r_lock, flags);
/*
* Get the next work request entry to find where to put the data.
*/
if (qp->r_flags & QIB_R_REUSE_SGE)
qp->r_flags &= ~QIB_R_REUSE_SGE;
else {
int ret;
ret = qib_get_rwqe(qp, 0);
if (ret < 0) {
qib_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
goto bail_unlock;
}
if (!ret) {
if (qp->ibqp.qp_num == 0)
ibp->n_vl15_dropped++;
goto bail_unlock;
}
}
/* Silently drop packets which are too big. */
if (unlikely(wc.byte_len > qp->r_len)) {
qp->r_flags |= QIB_R_REUSE_SGE;
ibp->n_pkt_drops++;
goto bail_unlock;
}
if (ah_attr->ah_flags & IB_AH_GRH) {
qib_copy_sge(&qp->r_sge, &ah_attr->grh,
sizeof(struct ib_grh), 1);
wc.wc_flags |= IB_WC_GRH;
} else
qib_skip_sge(&qp->r_sge, sizeof(struct ib_grh), 1);
ssge.sg_list = swqe->sg_list + 1;
ssge.sge = *swqe->sg_list;
ssge.num_sge = swqe->wr.num_sge;
sge = &ssge.sge;
while (length) {
u32 len = sge->length;
if (len > length)
len = length;
if (len > sge->sge_length)
len = sge->sge_length;
BUG_ON(len == 0);
qib_copy_sge(&qp->r_sge, sge->vaddr, len, 1);
sge->vaddr += len;
sge->length -= len;
sge->sge_length -= len;
if (sge->sge_length == 0) {
if (--ssge.num_sge)
*sge = *ssge.sg_list++;
} else if (sge->length == 0 && sge->mr->lkey) {
if (++sge->n >= QIB_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;
}
length -= len;
}
qib_put_ss(&qp->r_sge);
if (!test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags))
goto bail_unlock;
wc.wr_id = qp->r_wr_id;
wc.status = IB_WC_SUCCESS;
wc.opcode = IB_WC_RECV;
wc.qp = &qp->ibqp;
wc.src_qp = sqp->ibqp.qp_num;
wc.pkey_index = qp->ibqp.qp_type == IB_QPT_GSI ?
swqe->wr.wr.ud.pkey_index : 0;
wc.slid = ppd->lid | (ah_attr->src_path_bits & ((1 << ppd->lmc) - 1));
wc.sl = ah_attr->sl;
wc.dlid_path_bits = ah_attr->dlid & ((1 << ppd->lmc) - 1);
wc.port_num = qp->port_num;
/* Signal completion event if the solicited bit is set. */
qib_cq_enter(to_icq(qp->ibqp.recv_cq), &wc,
swqe->wr.send_flags & IB_SEND_SOLICITED);
ibp->n_loop_pkts++;
bail_unlock:
spin_unlock_irqrestore(&qp->r_lock, flags);
drop:
if (atomic_dec_and_test(&qp->refcount))
wake_up(&qp->wait);
}
/**
* qib_make_ud_req - construct a UD request packet
* @qp: the QP
*
* Return 1 if constructed; otherwise, return 0.
*/
int qib_make_ud_req(struct qib_qp *qp)
{
struct qib_other_headers *ohdr;
struct ib_ah_attr *ah_attr;
struct qib_pportdata *ppd;
struct qib_ibport *ibp;
struct qib_swqe *wqe;
unsigned long flags;
u32 nwords;
u32 extra_bytes;
u32 bth0;
u16 lrh0;
u16 lid;
int ret = 0;
int next_cur;
spin_lock_irqsave(&qp->s_lock, flags);
if (!(ib_qib_state_ops[qp->state] & QIB_PROCESS_NEXT_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, IB_WC_WR_FLUSH_ERR);
goto done;
}
if (qp->s_cur == qp->s_head)
goto bail;
wqe = get_swqe_ptr(qp, qp->s_cur);
next_cur = qp->s_cur + 1;
if (next_cur >= qp->s_size)
next_cur = 0;
/* Construct the header. */
ibp = to_iport(qp->ibqp.device, qp->port_num);
ppd = ppd_from_ibp(ibp);
ah_attr = &to_iah(wqe->wr.wr.ud.ah)->attr;
if (ah_attr->dlid >= QIB_MULTICAST_LID_BASE) {
if (ah_attr->dlid != QIB_PERMISSIVE_LID)
ibp->n_multicast_xmit++;
else
ibp->n_unicast_xmit++;
} else {
ibp->n_unicast_xmit++;
lid = ah_attr->dlid & ~((1 << ppd->lmc) - 1);
if (unlikely(lid == ppd->lid)) {
/*
* If DMAs are in progress, we can't generate
* a completion for the loopback packet since
* it would be out of order.
* XXX Instead of waiting, we could queue a
* zero length descriptor so we get a callback.
*/
if (atomic_read(&qp->s_dma_busy)) {
qp->s_flags |= QIB_S_WAIT_DMA;
goto bail;
}
qp->s_cur = next_cur;
spin_unlock_irqrestore(&qp->s_lock, flags);
qib_ud_loopback(qp, wqe);
spin_lock_irqsave(&qp->s_lock, flags);
qib_send_complete(qp, wqe, IB_WC_SUCCESS);
goto done;
}
}
qp->s_cur = next_cur;
extra_bytes = -wqe->length & 3;
nwords = (wqe->length + extra_bytes) >> 2;
/* header size in 32-bit words LRH+BTH+DETH = (8+12+8)/4. */
qp->s_hdrwords = 7;
qp->s_cur_size = wqe->length;
qp->s_cur_sge = &qp->s_sge;
qp->s_srate = ah_attr->static_rate;
qp->s_wqe = wqe;
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;
if (ah_attr->ah_flags & IB_AH_GRH) {
/* Header size in 32-bit words. */
qp->s_hdrwords += qib_make_grh(ibp, &qp->s_hdr->u.l.grh,
&ah_attr->grh,
qp->s_hdrwords, nwords);
lrh0 = QIB_LRH_GRH;
ohdr = &qp->s_hdr->u.l.oth;
/*
* Don't worry about sending to locally attached multicast
* QPs. It is unspecified by the spec. what happens.
*/
} else {
/* Header size in 32-bit words. */
lrh0 = QIB_LRH_BTH;
ohdr = &qp->s_hdr->u.oth;
}
if (wqe->wr.opcode == IB_WR_SEND_WITH_IMM) {
qp->s_hdrwords++;
ohdr->u.ud.imm_data = wqe->wr.ex.imm_data;
bth0 = IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE << 24;
} else
bth0 = IB_OPCODE_UD_SEND_ONLY << 24;
lrh0 |= ah_attr->sl << 4;
if (qp->ibqp.qp_type == IB_QPT_SMI)
lrh0 |= 0xF000; /* Set VL (see ch. 13.5.3.1) */
else
lrh0 |= ibp->sl_to_vl[ah_attr->sl] << 12;
qp->s_hdr->lrh[0] = cpu_to_be16(lrh0);
qp->s_hdr->lrh[1] = cpu_to_be16(ah_attr->dlid); /* DEST LID */
qp->s_hdr->lrh[2] = cpu_to_be16(qp->s_hdrwords + nwords + SIZE_OF_CRC);
lid = ppd->lid;
if (lid) {
lid |= ah_attr->src_path_bits & ((1 << ppd->lmc) - 1);
qp->s_hdr->lrh[3] = cpu_to_be16(lid);
} else
qp->s_hdr->lrh[3] = IB_LID_PERMISSIVE;
if (wqe->wr.send_flags & IB_SEND_SOLICITED)
bth0 |= IB_BTH_SOLICITED;
bth0 |= extra_bytes << 20;
bth0 |= qp->ibqp.qp_type == IB_QPT_SMI ? QIB_DEFAULT_P_KEY :
qib_get_pkey(ibp, qp->ibqp.qp_type == IB_QPT_GSI ?
wqe->wr.wr.ud.pkey_index : qp->s_pkey_index);
ohdr->bth[0] = cpu_to_be32(bth0);
/*
* Use the multicast QP if the destination LID is a multicast LID.
*/
ohdr->bth[1] = ah_attr->dlid >= QIB_MULTICAST_LID_BASE &&
ah_attr->dlid != QIB_PERMISSIVE_LID ?
cpu_to_be32(QIB_MULTICAST_QPN) :
cpu_to_be32(wqe->wr.wr.ud.remote_qpn);
ohdr->bth[2] = cpu_to_be32(qp->s_next_psn++ & QIB_PSN_MASK);
/*
* Qkeys with the high order bit set mean use the
* qkey from the QP context instead of the WR (see 10.2.5).
*/
ohdr->u.ud.deth[0] = cpu_to_be32((int)wqe->wr.wr.ud.remote_qkey < 0 ?
qp->qkey : wqe->wr.wr.ud.remote_qkey);
ohdr->u.ud.deth[1] = cpu_to_be32(qp->ibqp.qp_num);
done:
ret = 1;
goto unlock;
bail:
qp->s_flags &= ~QIB_S_BUSY;
unlock:
spin_unlock_irqrestore(&qp->s_lock, flags);
return ret;
}
static unsigned qib_lookup_pkey(struct qib_ibport *ibp, u16 pkey)
{
struct qib_pportdata *ppd = ppd_from_ibp(ibp);
struct qib_devdata *dd = ppd->dd;
unsigned ctxt = ppd->hw_pidx;
unsigned i;
pkey &= 0x7fff; /* remove limited/full membership bit */
for (i = 0; i < ARRAY_SIZE(dd->rcd[ctxt]->pkeys); ++i)
if ((dd->rcd[ctxt]->pkeys[i] & 0x7fff) == pkey)
return i;
/*
* Should not get here, this means hardware failed to validate pkeys.
* Punt and return index 0.
*/
return 0;
}
/**
* qib_ud_rcv - receive an incoming UD packet
* @ibp: the port the packet came in on
* @hdr: the packet header
* @has_grh: true if the packet has a GRH
* @data: the packet data
* @tlen: the packet length
* @qp: the QP the packet came on
*
* This is called from qib_qp_rcv() to process an incoming UD packet
* for the given QP.
* Called at interrupt level.
*/
void qib_ud_rcv(struct qib_ibport *ibp, struct qib_ib_header *hdr,
int has_grh, void *data, u32 tlen, struct qib_qp *qp)
{
struct qib_other_headers *ohdr;
int opcode;
u32 hdrsize;
u32 pad;
struct ib_wc wc;
u32 qkey;
u32 src_qp;
u16 dlid;
/* Check for GRH */
if (!has_grh) {
ohdr = &hdr->u.oth;
hdrsize = 8 + 12 + 8; /* LRH + BTH + DETH */
} else {
ohdr = &hdr->u.l.oth;
hdrsize = 8 + 40 + 12 + 8; /* LRH + GRH + BTH + DETH */
}
qkey = be32_to_cpu(ohdr->u.ud.deth[0]);
src_qp = be32_to_cpu(ohdr->u.ud.deth[1]) & QIB_QPN_MASK;
/*
* Get the number of bytes the message was padded by
* and drop incomplete packets.
*/
pad = (be32_to_cpu(ohdr->bth[0]) >> 20) & 3;
if (unlikely(tlen < (hdrsize + pad + 4)))
goto drop;
tlen -= hdrsize + pad + 4;
/*
* Check that the permissive LID is only used on QP0
* and the QKEY matches (see 9.6.1.4.1 and 9.6.1.5.1).
*/
if (qp->ibqp.qp_num) {
if (unlikely(hdr->lrh[1] == IB_LID_PERMISSIVE ||
hdr->lrh[3] == IB_LID_PERMISSIVE))
goto drop;
if (qp->ibqp.qp_num > 1) {
u16 pkey1, pkey2;
pkey1 = be32_to_cpu(ohdr->bth[0]);
pkey2 = qib_get_pkey(ibp, qp->s_pkey_index);
if (unlikely(!qib_pkey_ok(pkey1, pkey2))) {
qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_PKEY,
pkey1,
(be16_to_cpu(hdr->lrh[0]) >> 4) &
0xF,
src_qp, qp->ibqp.qp_num,
hdr->lrh[3], hdr->lrh[1]);
return;
}
}
if (unlikely(qkey != qp->qkey)) {
qib_bad_pqkey(ibp, IB_NOTICE_TRAP_BAD_QKEY, qkey,
(be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF,
src_qp, qp->ibqp.qp_num,
hdr->lrh[3], hdr->lrh[1]);
return;
}
/* Drop invalid MAD packets (see 13.5.3.1). */
if (unlikely(qp->ibqp.qp_num == 1 &&
(tlen != 256 ||
(be16_to_cpu(hdr->lrh[0]) >> 12) == 15)))
goto drop;
} else {
struct ib_smp *smp;
/* Drop invalid MAD packets (see 13.5.3.1). */
if (tlen != 256 || (be16_to_cpu(hdr->lrh[0]) >> 12) != 15)
goto drop;
smp = (struct ib_smp *) data;
if ((hdr->lrh[1] == IB_LID_PERMISSIVE ||
hdr->lrh[3] == IB_LID_PERMISSIVE) &&
smp->mgmt_class != IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE)
goto drop;
}
/*
* The opcode is in the low byte when its in network order
* (top byte when in host order).
*/
opcode = be32_to_cpu(ohdr->bth[0]) >> 24;
if (qp->ibqp.qp_num > 1 &&
opcode == IB_OPCODE_UD_SEND_ONLY_WITH_IMMEDIATE) {
wc.ex.imm_data = ohdr->u.ud.imm_data;
wc.wc_flags = IB_WC_WITH_IMM;
tlen -= sizeof(u32);
} else if (opcode == IB_OPCODE_UD_SEND_ONLY) {
wc.ex.imm_data = 0;
wc.wc_flags = 0;
} else
goto drop;
/*
* A GRH is expected to precede the data even if not
* present on the wire.
*/
wc.byte_len = tlen + sizeof(struct ib_grh);
/*
* Get the next work request entry to find where to put the data.
*/
if (qp->r_flags & QIB_R_REUSE_SGE)
qp->r_flags &= ~QIB_R_REUSE_SGE;
else {
int ret;
ret = qib_get_rwqe(qp, 0);
if (ret < 0) {
qib_rc_error(qp, IB_WC_LOC_QP_OP_ERR);
return;
}
if (!ret) {
if (qp->ibqp.qp_num == 0)
ibp->n_vl15_dropped++;
return;
}
}
/* Silently drop packets which are too big. */
if (unlikely(wc.byte_len > qp->r_len)) {
qp->r_flags |= QIB_R_REUSE_SGE;
goto drop;
}
if (has_grh) {
qib_copy_sge(&qp->r_sge, &hdr->u.l.grh,
sizeof(struct ib_grh), 1);
wc.wc_flags |= IB_WC_GRH;
} else
qib_skip_sge(&qp->r_sge, sizeof(struct ib_grh), 1);
qib_copy_sge(&qp->r_sge, data, wc.byte_len - sizeof(struct ib_grh), 1);
qib_put_ss(&qp->r_sge);
if (!test_and_clear_bit(QIB_R_WRID_VALID, &qp->r_aflags))
return;
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 = src_qp;
wc.pkey_index = qp->ibqp.qp_type == IB_QPT_GSI ?
qib_lookup_pkey(ibp, be32_to_cpu(ohdr->bth[0])) : 0;
wc.slid = be16_to_cpu(hdr->lrh[3]);
wc.sl = (be16_to_cpu(hdr->lrh[0]) >> 4) & 0xF;
dlid = be16_to_cpu(hdr->lrh[1]);
/*
* Save the LMC lower bits if the destination LID is a unicast LID.
*/
wc.dlid_path_bits = dlid >= QIB_MULTICAST_LID_BASE ? 0 :
dlid & ((1 << ppd_from_ibp(ibp)->lmc) - 1);
wc.port_num = qp->port_num;
/* 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);
return;
drop:
ibp->n_pkt_drops++;
}
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