/*
* 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 "ips_common.h"
/* cut down ridiculously long IB macro names */
#define OP(x) IB_OPCODE_RC_##x
/**
* 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.
*/
static void ipath_init_restart(struct ipath_qp *qp, struct ipath_swqe *wqe)
{
struct ipath_ibdev *dev;
u32 len;
len = ((qp->s_psn - wqe->psn) & IPS_PSN_MASK) *
ib_mtu_enum_to_int(qp->path_mtu);
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;
ipath_skip_sge(&qp->s_sge, len);
qp->s_len = wqe->length - len;
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 bth0 if constructed; otherwise, return 0.
* Note the QP s_lock must be held.
*/
static inline u32 ipath_make_rc_ack(struct ipath_qp *qp,
struct ipath_other_headers *ohdr,
u32 pmtu)
{
struct ipath_sge_state *ss;
u32 hwords;
u32 len;
u32 bth0;
/* header size in 32-bit words LRH+BTH = (8+12)/4. */
hwords = 5;
/*
* Send a response. Note that we are in the responder's
* side of the QP context.
*/
switch (qp->s_ack_state) {
case OP(RDMA_READ_REQUEST):
ss = &qp->s_rdma_sge;
len = qp->s_rdma_len;
if (len > pmtu) {
len = pmtu;
qp->s_ack_state = OP(RDMA_READ_RESPONSE_FIRST);
}
else
qp->s_ack_state = OP(RDMA_READ_RESPONSE_ONLY);
qp->s_rdma_len -= len;
bth0 = qp->s_ack_state << 24;
ohdr->u.aeth = ipath_compute_aeth(qp);
hwords++;
break;
case OP(RDMA_READ_RESPONSE_FIRST):
qp->s_ack_state = OP(RDMA_READ_RESPONSE_MIDDLE);
/* FALLTHROUGH */
case OP(RDMA_READ_RESPONSE_MIDDLE):
ss = &qp->s_rdma_sge;
len = qp->s_rdma_len;
if (len > pmtu)
len = pmtu;
else {
ohdr->u.aeth = ipath_compute_aeth(qp);
hwords++;
qp->s_ack_state = OP(RDMA_READ_RESPONSE_LAST);
}
qp->s_rdma_len -= len;
bth0 = qp->s_ack_state << 24;
break;
case OP(RDMA_READ_RESPONSE_LAST):
case OP(RDMA_READ_RESPONSE_ONLY):
/*
* We have to prevent new requests from changing
* the r_sge state while a ipath_verbs_send()
* is in progress.
* Changing r_state allows the receiver
* to continue processing new packets.
* We do it here now instead of above so
* that we are sure the packet was sent before
* changing the state.
*/
qp->r_state = OP(RDMA_READ_RESPONSE_LAST);
qp->s_ack_state = OP(ACKNOWLEDGE);
return 0;
case OP(COMPARE_SWAP):
case OP(FETCH_ADD):
ss = NULL;
len = 0;
qp->r_state = OP(SEND_LAST);
qp->s_ack_state = OP(ACKNOWLEDGE);
bth0 = IB_OPCODE_ATOMIC_ACKNOWLEDGE << 24;
ohdr->u.at.aeth = ipath_compute_aeth(qp);
ohdr->u.at.atomic_ack_eth = cpu_to_be64(qp->s_ack_atomic);
hwords += sizeof(ohdr->u.at) / 4;
break;
default:
/* Send a regular ACK. */
ss = NULL;
len = 0;
qp->s_ack_state = OP(ACKNOWLEDGE);
bth0 = qp->s_ack_state << 24;
ohdr->u.aeth = ipath_compute_aeth(qp);
hwords++;
}
qp->s_hdrwords = hwords;
qp->s_cur_sge = ss;
qp->s_cur_size = len;
return bth0;
}
/**
* 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.
*/
static inline 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;
if (!(ib_ipath_state_ops[qp->state] & IPATH_PROCESS_SEND_OK) ||
qp->s_rnr_timeout)
goto done;
/* 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 done;
qp->s_psn = 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.
*/
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 = 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 done;
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++;
/* 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 done;
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) / 4;
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:
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) / 4;
if (newreq) {
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++;
}
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:
if (wqe->wr.opcode == IB_WR_ATOMIC_CMP_AND_SWP)
qp->s_state = OP(COMPARE_SWAP);
else
qp->s_state = OP(FETCH_ADD);
ohdr->u.atomic_eth.vaddr = cpu_to_be64(
wqe->wr.wr.atomic.remote_addr);
ohdr->u.atomic_eth.rkey = cpu_to_be32(
wqe->wr.wr.atomic.rkey);
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);
hwords += sizeof(struct ib_atomic_eth) / 4;
if (newreq) {
qp->s_lsn++;
wqe->lpsn = wqe->psn;
}
if (++qp->s_cur == qp->s_size)
qp->s_cur = 0;
ss = NULL;
len = 0;
break;
default:
goto done;
}
if (newreq) {
qp->s_tail++;
if (qp->s_tail >= qp->s_size)
qp->s_tail = 0;
}
bth2 |= qp->s_psn++ & IPS_PSN_MASK;
if ((int)(qp->s_psn - qp->s_next_psn) > 0)
qp->s_next_psn = qp->s_psn;
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++ & IPS_PSN_MASK;
if ((int)(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) {
/*
* Request an ACK every 1/2 MB to avoid retransmit
* timeouts.
*/
if (((wqe->length - len) % (512 * 1024)) == 0)
bth2 |= 1 << 31;
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++ & IPS_PSN_MASK;
if ((int)(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) {
/*
* Request an ACK every 1/2 MB to avoid retransmit
* timeouts.
*/
if (((wqe->length - len) % (512 * 1024)) == 0)
bth2 |= 1 << 31;
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) & IPS_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) / 4;
bth2 = qp->s_psn++ & IPS_PSN_MASK;
if ((int)(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;
case OP(RDMA_READ_REQUEST):
case OP(COMPARE_SWAP):
case OP(FETCH_ADD):
/*
* We shouldn't start anything new until this request is
* finished. The ACK will handle rescheduling us. XXX The
* number of outstanding ones is negotiated at connection
* setup time (see pg. 258,289)? XXX Also, if we support
* multiple outstanding requests, we need to check the WQE
* IB_SEND_FENCE flag and not send a new request if a RDMA
* read or atomic is pending.
*/
goto done;
}
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;
return 1;
done:
return 0;
}
static inline void ipath_make_rc_grh(struct ipath_qp *qp,
struct ib_global_route *grh,
u32 nwords)
{
struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
/* GRH header size in 32-bit words. */
qp->s_hdrwords += 10;
qp->s_hdr.u.l.grh.version_tclass_flow =
cpu_to_be32((6 << 28) |
(grh->traffic_class << 20) |
grh->flow_label);
qp->s_hdr.u.l.grh.paylen =
cpu_to_be16(((qp->s_hdrwords - 12) + nwords +
SIZE_OF_CRC) << 2);
/* next_hdr is defined by C8-7 in ch. 8.4.1 */
qp->s_hdr.u.l.grh.next_hdr = 0x1B;
qp->s_hdr.u.l.grh.hop_limit = grh->hop_limit;
/* The SGID is 32-bit aligned. */
qp->s_hdr.u.l.grh.sgid.global.subnet_prefix = dev->gid_prefix;
qp->s_hdr.u.l.grh.sgid.global.interface_id =
ipath_layer_get_guid(dev->dd);
qp->s_hdr.u.l.grh.dgid = grh->dgid;
}
/**
* ipath_do_rc_send - perform a send on an RC 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_rc_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 ==
ipath_layer_get_lid(dev->dd))) {
struct ib_wc wc;
/*
* Pass in an uninitialized ib_wc to be consistent with
* other places where ipath_ruc_loopback() is called.
*/
ipath_ruc_loopback(qp, &wc);
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.
*/
_VERBS_INFO("h %u %p\n", qp->s_hdrwords, &qp->s_hdr);
_VERBS_INFO("d %u %p %u %p %u %u %u %u\n", qp->s_cur_size,
qp->s_cur_sge->sg_list,
qp->s_cur_sge->num_sge,
qp->s_cur_sge->sge.vaddr,
qp->s_cur_sge->sge.sge_length,
qp->s_cur_sge->sge.length,
qp->s_cur_sge->sge.m,
qp->s_cur_sge->sge.n);
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 != OP(ACKNOWLEDGE) &&
(bth0 = ipath_make_rc_ack(qp, ohdr, pmtu)) != 0)
bth2 = qp->s_ack_psn++ & IPS_PSN_MASK;
else if (!ipath_make_rc_req(qp, ohdr, pmtu, &bth0, &bth2))
goto done;
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 = IPS_LRH_BTH;
if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
ipath_make_rc_grh(qp, &qp->remote_ah_attr.grh, nwords);
lrh0 = IPS_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(ipath_layer_get_lid(dev->dd));
bth0 |= ipath_layer_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;
done:
spin_unlock_irqrestore(&qp->s_lock, flags);
clear:
clear_bit(IPATH_S_BUSY, &qp->s_flags);
bail:
return;
}
static void send_rc_ack(struct ipath_qp *qp)
{
struct ipath_ibdev *dev = to_idev(qp->ibqp.device);
u16 lrh0;
u32 bth0;
struct ipath_other_headers *ohdr;
/* Construct the header. */
ohdr = &qp->s_hdr.u.oth;
lrh0 = IPS_LRH_BTH;
/* header size in 32-bit words LRH+BTH+AETH = (8+12+4)/4. */
qp->s_hdrwords = 6;
if (unlikely(qp->remote_ah_attr.ah_flags & IB_AH_GRH)) {
ipath_make_rc_grh(qp, &qp->remote_ah_attr.grh, 0);
ohdr = &qp->s_hdr.u.l.oth;
lrh0 = IPS_LRH_GRH;
}
bth0 = ipath_layer_get_pkey(dev->dd, qp->s_pkey_index);
ohdr->u.aeth = ipath_compute_aeth(qp);
if (qp->s_ack_state >= OP(COMPARE_SWAP)) {
bth0 |= IB_OPCODE_ATOMIC_ACKNOWLEDGE << 24;
ohdr->u.at.atomic_ack_eth = cpu_to_be64(qp->s_ack_atomic);
qp->s_hdrwords += sizeof(ohdr->u.at.atomic_ack_eth) / 4;
}
else
bth0 |= OP(ACKNOWLEDGE) << 24;
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 + SIZE_OF_CRC);
qp->s_hdr.lrh[3] = cpu_to_be16(ipath_layer_get_lid(dev->dd));
ohdr->bth[0] = cpu_to_be32(bth0);
ohdr->bth[1] = cpu_to_be32(qp->remote_qpn);
ohdr->bth[2] = cpu_to_be32(qp->s_ack_psn & IPS_PSN_MASK);
/*
* If we can send the ACK, clear the ACK state.
*/
if (ipath_verbs_send(dev->dd, qp->s_hdrwords, (u32 *) &qp->s_hdr,
0, NULL) == 0) {
qp->s_ack_state = OP(ACKNOWLEDGE);
dev->n_rc_qacks++;
dev->n_unicast_xmit++;
}
}
/**
* 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.
*/
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;
u32 n;
/*
* If there are no requests pending, we are done.
*/
if (ipath_cmp24(psn, qp->s_next_psn) >= 0 ||
qp->s_last == qp->s_tail)
goto done;
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_num = qp->ibqp.qp_num;
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 += (int)qp->s_psn - (int)psn;
/*
* If we are starting the request from the beginning, let the normal
* send code handle initialization.
*/
qp->s_cur = qp->s_last;
if (ipath_cmp24(psn, wqe->psn) <= 0) {
qp->s_state = OP(SEND_LAST);
qp->s_psn = wqe->psn;
} else {
n = qp->s_cur;
for (;;) {
if (++n == qp->s_size)
n = 0;
if (n == qp->s_tail) {
if (ipath_cmp24(psn, qp->s_next_psn) >= 0) {
qp->s_cur = n;
wqe = get_swqe_ptr(qp, n);
}
break;
}
wqe = get_swqe_ptr(qp, n);
if (ipath_cmp24(psn, wqe->psn) < 0)
break;
qp->s_cur = n;
}
qp->s_psn = psn;
/*
* Reset 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 (wqe->wr.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:
tasklet_hi_schedule(&qp->s_task);
bail:
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)
{
struct ipath_swqe *wqe;
u32 n;
n = qp->s_cur;
wqe = get_swqe_ptr(qp, n);
for (;;) {
if (++n == qp->s_size)
n = 0;
if (n == qp->s_tail) {
if (ipath_cmp24(psn, qp->s_next_psn) >= 0) {
qp->s_cur = n;
wqe = get_swqe_ptr(qp, n);
}
break;
}
wqe = get_swqe_ptr(qp, n);
if (ipath_cmp24(psn, wqe->psn) < 0)
break;
qp->s_cur = n;
}
qp->s_psn = psn;
/*
* 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 (wqe->wr.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);
}
}
/**
* 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() 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 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;
/*
* 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).
*/
wqe = get_swqe_ptr(qp, qp->s_last);
/* Nothing is pending to ACK/NAK. */
if (qp->s_last == qp->s_tail)
goto bail;
/*
* The MSN might be for a later WQE than the PSN indicates so
* only complete WQEs that the PSN finishes.
*/
while (ipath_cmp24(psn, wqe->lpsn) >= 0) {
/* If we are ACKing a WQE, the MSN should be >= the SSN. */
if (ipath_cmp24(aeth, wqe->ssn) < 0)
break;
/*
* 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)) ||
((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.
*/
qp->s_last_psn = 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;
}
/* Post a send completion queue entry if requested. */
if (!test_bit(IPATH_S_SIGNAL_REQ_WR, &qp->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_num = qp->ibqp.qp_num;
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_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;
wqe = get_swqe_ptr(qp, qp->s_cur);
qp->s_state = OP(SEND_LAST);
qp->s_psn = wqe->psn;
}
if (++qp->s_last >= qp->s_size)
qp->s_last = 0;
wqe = get_swqe_ptr(qp, qp->s_last);
if (qp->s_last == qp->s_tail)
break;
}
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);
}
ipath_get_credit(qp, aeth);
qp->s_rnr_retry = qp->s_rnr_retry_cnt;
qp->s_retry = qp->s_retry_cnt;
qp->s_last_psn = psn;
ret = 1;
goto bail;
case 1: /* RNR NAK */
dev->n_rnr_naks++;
if (qp->s_rnr_retry == 0) {
if (qp->s_last == qp->s_tail)
goto bail;
wc.status = IB_WC_RNR_RETRY_EXC_ERR;
goto class_b;
}
if (qp->s_rnr_retry_cnt < 7)
qp->s_rnr_retry--;
if (qp->s_last == qp->s_tail)
goto bail;
/* The last valid PSN seen is the previous request's. */
qp->s_last_psn = wqe->psn - 1;
dev->n_rc_resends += (int)qp->s_psn - (int)psn;
/*
* If we are starting the request from the beginning, let
* the normal send code handle initialization.
*/
qp->s_cur = qp->s_last;
wqe = get_swqe_ptr(qp, qp->s_cur);
if (ipath_cmp24(psn, wqe->psn) <= 0) {
qp->s_state = OP(SEND_LAST);
qp->s_psn = wqe->psn;
} else
reset_psn(qp, psn);
qp->s_rnr_timeout =
ib_ipath_rnr_table[(aeth >> IPS_AETH_CREDIT_SHIFT) &
IPS_AETH_CREDIT_MASK];
ipath_insert_rnr_queue(qp);
goto bail;
case 3: /* NAK */
/* The last valid PSN seen is the previous request's. */
if (qp->s_last != qp->s_tail)
qp->s_last_psn = wqe->psn - 1;
switch ((aeth >> IPS_AETH_CREDIT_SHIFT) &
IPS_AETH_CREDIT_MASK) {
case 0: /* PSN sequence error */
dev->n_seq_naks++;
/*
* Back up to the responder's expected PSN. XXX
* Note that we might get a NAK in the middle of an
* RDMA READ response which terminates the RDMA
* READ.
*/
if (qp->s_last == qp->s_tail)
break;
if (ipath_cmp24(psn, wqe->psn) < 0)
break;
/* Retry the request. */
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_num = qp->ibqp.qp_num;
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)
{
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;
}
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 *) qp->s_sge.sge.vaddr = *(u64 *) data;
if (!do_rc_ack(qp, aeth, psn, opcode) ||
opcode != OP(RDMA_READ_RESPONSE_FIRST))
goto ack_done;
hdrsize += 4;
/*
* do_rc_ack() has already checked the PSN so skip
* the sequence check.
*/
goto rdma_read;
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;
}
rdma_read:
if (unlikely(qp->s_state != OP(RDMA_READ_REQUEST)))
goto ack_done;
if (unlikely(tlen != (hdrsize + pmtu + 4)))
goto ack_done;
if (unlikely(pmtu >= qp->s_len))
goto ack_done;
/* We got a response so update the timeout. */
if (unlikely(qp->s_last == qp->s_tail ||
get_swqe_ptr(qp, qp->s_last)->wr.opcode !=
IB_WR_RDMA_READ))
goto ack_done;
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. XXX Yet another place that
* affects relaxed RDMA order since we don't want s_sge modified.
*/
qp->s_len -= pmtu;
qp->s_last_psn = psn;
spin_unlock_irqrestore(&qp->s_lock, flags);
ipath_copy_sge(&qp->s_sge, data, pmtu);
goto bail;
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;
}
/* FALLTHROUGH */
case OP(RDMA_READ_RESPONSE_ONLY):
if (unlikely(qp->s_state != OP(RDMA_READ_REQUEST)))
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 >= 1 && <= pmtu.
* Remember to account for the AETH header (4) and
* ICRC (4).
*/
if (unlikely(tlen <= (hdrsize + pad + 8))) {
/*
* XXX Need to generate an error CQ
* entry.
*/
goto ack_done;
}
tlen -= hdrsize + pad + 8;
if (unlikely(tlen != qp->s_len)) {
/*
* XXX Need to generate an error CQ
* entry.
*/
goto ack_done;
}
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_sge, data, tlen);
if (do_rc_ack(qp, aeth, psn, OP(RDMA_READ_RESPONSE_LAST))) {
/*
* Change the state so we contimue
* processing new requests.
*/
qp->s_state = OP(SEND_LAST);
}
goto ack_done;
}
ack_done:
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 and the s_lock unlocked.
*/
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 ib_reth *reth;
if (diff > 0) {
/*
* Packet sequence error.
* A NAK will ACK earlier sends and RDMA writes.
* Don't queue the NAK if a RDMA read, atomic, or
* NAK is pending though.
*/
spin_lock(&qp->s_lock);
if ((qp->s_ack_state >= OP(RDMA_READ_REQUEST) &&
qp->s_ack_state != IB_OPCODE_ACKNOWLEDGE) ||
qp->s_nak_state != 0) {
spin_unlock(&qp->s_lock);
goto done;
}
qp->s_ack_state = OP(SEND_ONLY);
qp->s_nak_state = IB_NAK_PSN_ERROR;
/* Use the expected PSN. */
qp->s_ack_psn = qp->r_psn;
goto resched;
}
/*
* 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.
*/
spin_lock(&qp->s_lock);
if (qp->s_ack_state != IB_OPCODE_ACKNOWLEDGE &&
ipath_cmp24(psn, qp->s_ack_psn) >= 0) {
if (qp->s_ack_state < IB_OPCODE_RDMA_READ_REQUEST)
qp->s_ack_psn = psn;
spin_unlock(&qp->s_lock);
goto done;
}
switch (opcode) {
case OP(RDMA_READ_REQUEST):
/*
* We have to be careful to not change s_rdma_sge
* while ipath_do_rc_send() is using it and not
* holding the s_lock.
*/
if (qp->s_ack_state != OP(ACKNOWLEDGE) &&
qp->s_ack_state >= IB_OPCODE_RDMA_READ_REQUEST) {
spin_unlock(&qp->s_lock);
dev->n_rdma_dup_busy++;
goto done;
}
/* RETH comes after BTH */
if (!header_in_data)
reth = &ohdr->u.rc.reth;
else {
reth = (struct ib_reth *)data;
data += sizeof(*reth);
}
qp->s_rdma_len = be32_to_cpu(reth->length);
if (qp->s_rdma_len != 0) {
u32 rkey = be32_to_cpu(reth->rkey);
u64 vaddr = be64_to_cpu(reth->vaddr);
int ok;
/*
* Address range must be a subset of the original
* request and start on pmtu boundaries.
*/
ok = ipath_rkey_ok(dev, &qp->s_rdma_sge,
qp->s_rdma_len, vaddr, rkey,
IB_ACCESS_REMOTE_READ);
if (unlikely(!ok))
goto done;
} else {
qp->s_rdma_sge.sg_list = NULL;
qp->s_rdma_sge.num_sge = 0;
qp->s_rdma_sge.sge.mr = NULL;
qp->s_rdma_sge.sge.vaddr = NULL;
qp->s_rdma_sge.sge.length = 0;
qp->s_rdma_sge.sge.sge_length = 0;
}
break;
case OP(COMPARE_SWAP):
case OP(FETCH_ADD):
/*
* Check for the PSN of the last atomic operations
* performed and resend the result if found.
*/
if ((psn & IPS_PSN_MASK) != qp->r_atomic_psn) {
spin_unlock(&qp->s_lock);
goto done;
}
qp->s_ack_atomic = qp->r_atomic_data;
break;
}
qp->s_ack_state = opcode;
qp->s_nak_state = 0;
qp->s_ack_psn = psn;
resched:
return 0;
done:
return 1;
}
/**
* 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;
unsigned long flags;
struct ib_wc wc;
u32 pmtu = ib_mtu_enum_to_int(qp->path_mtu);
int diff;
struct ib_reth *reth;
int header_in_data;
/* 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 =
ipath_layer_get_rcvhdrentsize(dev->dd) == 16;
if (header_in_data) {
psn = be32_to_cpu(((__be32 *) data)[0]);
data += sizeof(__be32);
} else
psn = be32_to_cpu(ohdr->bth[2]);
}
/*
* 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;
/*
* 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)) {
ipath_rc_rcv_resp(dev, ohdr, data, tlen, qp, opcode, psn,
hdrsize, pmtu, header_in_data);
goto bail;
}
spin_lock_irqsave(&qp->r_rq.lock, flags);
/* 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 resched;
}
/* 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:
/*
* A NAK will ACK earlier sends and RDMA writes. Don't queue the
* NAK if a RDMA read, atomic, or NAK is pending though.
*/
spin_lock(&qp->s_lock);
if (qp->s_ack_state >= OP(RDMA_READ_REQUEST) &&
qp->s_ack_state != IB_OPCODE_ACKNOWLEDGE) {
spin_unlock(&qp->s_lock);
goto done;
}
/* XXX Flush WQEs */
qp->state = IB_QPS_ERR;
qp->s_ack_state = OP(SEND_ONLY);
qp->s_nak_state = IB_NAK_INVALID_REQUEST;
qp->s_ack_psn = qp->r_psn;
goto resched;
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;
case OP(RDMA_READ_REQUEST):
case OP(COMPARE_SWAP):
case OP(FETCH_ADD):
/*
* Drop all new requests until a response has been sent. A
* new request then ACKs the RDMA response we sent. Relaxed
* ordering would allow new requests to be processed but we
* would need to keep a queue of rwqe's for all that are in
* progress. Note that we can't RNR NAK this request since
* the RDMA READ or atomic response is already queued to be
* sent (unless we implement a response send queue).
*/
goto done;
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;
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.
*/
spin_lock(&qp->s_lock);
if (qp->s_ack_state >=
OP(RDMA_READ_REQUEST) &&
qp->s_ack_state != IB_OPCODE_ACKNOWLEDGE) {
spin_unlock(&qp->s_lock);
goto done;
}
qp->s_ack_state = OP(SEND_ONLY);
qp->s_nak_state = IB_RNR_NAK | qp->s_min_rnr_timer;
qp->s_ack_psn = qp->r_psn;
goto resched;
}
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);
atomic_inc(&qp->msn);
if (opcode == OP(RDMA_WRITE_LAST) ||
opcode == OP(RDMA_WRITE_ONLY))
break;
wc.wr_id = qp->r_wr_id;
wc.status = IB_WC_SUCCESS;
wc.opcode = IB_WC_RECV;
wc.vendor_err = 0;
wc.qp_num = qp->ibqp.qp_num;
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(dev, &qp->r_sge,
qp->r_len, vaddr, rkey,
IB_ACCESS_REMOTE_WRITE);
if (unlikely(!ok)) {
nack_acc:
/*
* A NAK will ACK earlier sends and RDMA
* writes. Don't queue the NAK if a RDMA
* read, atomic, or NAK is pending though.
*/
spin_lock(&qp->s_lock);
if (qp->s_ack_state >=
OP(RDMA_READ_REQUEST) &&
qp->s_ack_state !=
IB_OPCODE_ACKNOWLEDGE) {
spin_unlock(&qp->s_lock);
goto done;
}
/* XXX Flush WQEs */
qp->state = IB_QPS_ERR;
qp->s_ack_state = OP(RDMA_WRITE_ONLY);
qp->s_nak_state =
IB_NAK_REMOTE_ACCESS_ERROR;
qp->s_ack_psn = qp->r_psn;
goto resched;
}
} 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):
/* RETH comes after BTH */
if (!header_in_data)
reth = &ohdr->u.rc.reth;
else {
reth = (struct ib_reth *)data;
data += sizeof(*reth);
}
spin_lock(&qp->s_lock);
if (qp->s_ack_state != OP(ACKNOWLEDGE) &&
qp->s_ack_state >= IB_OPCODE_RDMA_READ_REQUEST) {
spin_unlock(&qp->s_lock);
goto done;
}
qp->s_rdma_len = be32_to_cpu(reth->length);
if (qp->s_rdma_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(dev, &qp->s_rdma_sge,
qp->s_rdma_len, vaddr, rkey,
IB_ACCESS_REMOTE_READ);
if (unlikely(!ok)) {
spin_unlock(&qp->s_lock);
goto nack_acc;
}
/*
* Update the next expected PSN. We add 1 later
* below, so only add the remainder here.
*/
if (qp->s_rdma_len > pmtu)
qp->r_psn += (qp->s_rdma_len - 1) / pmtu;
} else {
qp->s_rdma_sge.sg_list = NULL;
qp->s_rdma_sge.num_sge = 0;
qp->s_rdma_sge.sge.mr = NULL;
qp->s_rdma_sge.sge.vaddr = NULL;
qp->s_rdma_sge.sge.length = 0;
qp->s_rdma_sge.sge.sge_length = 0;
}
if (unlikely(!(qp->qp_access_flags &
IB_ACCESS_REMOTE_READ)))
goto nack_acc;
/*
* 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.
*/
atomic_inc(&qp->msn);
qp->s_ack_state = opcode;
qp->s_nak_state = 0;
qp->s_ack_psn = psn;
qp->r_psn++;
qp->r_state = opcode;
goto rdmadone;
case OP(COMPARE_SWAP):
case OP(FETCH_ADD): {
struct ib_atomic_eth *ateth;
u64 vaddr;
u64 sdata;
u32 rkey;
if (!header_in_data)
ateth = &ohdr->u.atomic_eth;
else {
ateth = (struct ib_atomic_eth *)data;
data += sizeof(*ateth);
}
vaddr = be64_to_cpu(ateth->vaddr);
if (unlikely(vaddr & (sizeof(u64) - 1)))
goto nack_inv;
rkey = be32_to_cpu(ateth->rkey);
/* Check rkey & NAK */
if (unlikely(!ipath_rkey_ok(dev, &qp->r_sge,
sizeof(u64), vaddr, rkey,
IB_ACCESS_REMOTE_ATOMIC)))
goto nack_acc;
if (unlikely(!(qp->qp_access_flags &
IB_ACCESS_REMOTE_ATOMIC)))
goto nack_acc;
/* Perform atomic OP and save result. */
sdata = be64_to_cpu(ateth->swap_data);
spin_lock(&dev->pending_lock);
qp->r_atomic_data = *(u64 *) qp->r_sge.sge.vaddr;
if (opcode == OP(FETCH_ADD))
*(u64 *) qp->r_sge.sge.vaddr =
qp->r_atomic_data + sdata;
else if (qp->r_atomic_data ==
be64_to_cpu(ateth->compare_data))
*(u64 *) qp->r_sge.sge.vaddr = sdata;
spin_unlock(&dev->pending_lock);
atomic_inc(&qp->msn);
qp->r_atomic_psn = psn & IPS_PSN_MASK;
psn |= 1 << 31;
break;
}
default:
/* Drop packet for unknown opcodes. */
goto done;
}
qp->r_psn++;
qp->r_state = opcode;
/* Send an ACK if requested or required. */
if (psn & (1 << 31)) {
/*
* Coalesce ACKs unless there is a RDMA READ or
* ATOMIC pending.
*/
spin_lock(&qp->s_lock);
if (qp->s_ack_state == OP(ACKNOWLEDGE) ||
qp->s_ack_state < IB_OPCODE_RDMA_READ_REQUEST) {
qp->s_ack_state = opcode;
qp->s_nak_state = 0;
qp->s_ack_psn = psn;
qp->s_ack_atomic = qp->r_atomic_data;
goto resched;
}
spin_unlock(&qp->s_lock);
}
done:
spin_unlock_irqrestore(&qp->r_rq.lock, flags);
goto bail;
resched:
/*
* Try to send ACK right away but not if ipath_do_rc_send() is
* active.
*/
if (qp->s_hdrwords == 0 &&
(qp->s_ack_state < IB_OPCODE_RDMA_READ_REQUEST ||
qp->s_ack_state >= IB_OPCODE_COMPARE_SWAP))
send_rc_ack(qp);
rdmadone:
spin_unlock(&qp->s_lock);
spin_unlock_irqrestore(&qp->r_rq.lock, flags);
/* Call ipath_do_rc_send() in another thread. */
tasklet_hi_schedule(&qp->s_task);
bail:
return;
}
