linux/drivers/infiniband/hw/ehca/ehca_reqs.c

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/*
* IBM eServer eHCA Infiniband device driver for Linux on POWER
*
* post_send/recv, poll_cq, req_notify
*
* Authors: Hoang-Nam Nguyen <hnguyen@de.ibm.com>
* Waleri Fomin <fomin@de.ibm.com>
* Joachim Fenkes <fenkes@de.ibm.com>
* Reinhard Ernst <rernst@de.ibm.com>
*
* Copyright (c) 2005 IBM Corporation
*
* All rights reserved.
*
* This source code is distributed under a dual license of GPL v2.0 and OpenIB
* BSD.
*
* OpenIB BSD License
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <asm-powerpc/system.h>
#include "ehca_classes.h"
#include "ehca_tools.h"
#include "ehca_qes.h"
#include "ehca_iverbs.h"
#include "hcp_if.h"
#include "hipz_fns.h"
static inline int ehca_write_rwqe(struct ipz_queue *ipz_rqueue,
struct ehca_wqe *wqe_p,
struct ib_recv_wr *recv_wr)
{
u8 cnt_ds;
if (unlikely((recv_wr->num_sge < 0) ||
(recv_wr->num_sge > ipz_rqueue->act_nr_of_sg))) {
ehca_gen_err("Invalid number of WQE SGE. "
"num_sqe=%x max_nr_of_sg=%x",
recv_wr->num_sge, ipz_rqueue->act_nr_of_sg);
return -EINVAL; /* invalid SG list length */
}
/* clear wqe header until sglist */
memset(wqe_p, 0, offsetof(struct ehca_wqe, u.ud_av.sg_list));
wqe_p->work_request_id = recv_wr->wr_id;
wqe_p->nr_of_data_seg = recv_wr->num_sge;
for (cnt_ds = 0; cnt_ds < recv_wr->num_sge; cnt_ds++) {
wqe_p->u.all_rcv.sg_list[cnt_ds].vaddr =
recv_wr->sg_list[cnt_ds].addr;
wqe_p->u.all_rcv.sg_list[cnt_ds].lkey =
recv_wr->sg_list[cnt_ds].lkey;
wqe_p->u.all_rcv.sg_list[cnt_ds].length =
recv_wr->sg_list[cnt_ds].length;
}
if (ehca_debug_level) {
ehca_gen_dbg("RECEIVE WQE written into ipz_rqueue=%p", ipz_rqueue);
ehca_dmp( wqe_p, 16*(6 + wqe_p->nr_of_data_seg), "recv wqe");
}
return 0;
}
#if defined(DEBUG_GSI_SEND_WR)
/* need ib_mad struct */
#include <rdma/ib_mad.h>
static void trace_send_wr_ud(const struct ib_send_wr *send_wr)
{
int idx;
int j;
while (send_wr) {
struct ib_mad_hdr *mad_hdr = send_wr->wr.ud.mad_hdr;
struct ib_sge *sge = send_wr->sg_list;
ehca_gen_dbg("send_wr#%x wr_id=%lx num_sge=%x "
"send_flags=%x opcode=%x",idx, send_wr->wr_id,
send_wr->num_sge, send_wr->send_flags,
send_wr->opcode);
if (mad_hdr) {
ehca_gen_dbg("send_wr#%x mad_hdr base_version=%x "
"mgmt_class=%x class_version=%x method=%x "
"status=%x class_specific=%x tid=%lx "
"attr_id=%x resv=%x attr_mod=%x",
idx, mad_hdr->base_version,
mad_hdr->mgmt_class,
mad_hdr->class_version, mad_hdr->method,
mad_hdr->status, mad_hdr->class_specific,
mad_hdr->tid, mad_hdr->attr_id,
mad_hdr->resv,
mad_hdr->attr_mod);
}
for (j = 0; j < send_wr->num_sge; j++) {
u8 *data = (u8 *) abs_to_virt(sge->addr);
ehca_gen_dbg("send_wr#%x sge#%x addr=%p length=%x "
"lkey=%x",
idx, j, data, sge->length, sge->lkey);
/* assume length is n*16 */
ehca_dmp(data, sge->length, "send_wr#%x sge#%x",
idx, j);
sge++;
} /* eof for j */
idx++;
send_wr = send_wr->next;
} /* eof while send_wr */
}
#endif /* DEBUG_GSI_SEND_WR */
static inline int ehca_write_swqe(struct ehca_qp *qp,
struct ehca_wqe *wqe_p,
const struct ib_send_wr *send_wr)
{
u32 idx;
u64 dma_length;
struct ehca_av *my_av;
u32 remote_qkey = send_wr->wr.ud.remote_qkey;
if (unlikely((send_wr->num_sge < 0) ||
(send_wr->num_sge > qp->ipz_squeue.act_nr_of_sg))) {
ehca_gen_err("Invalid number of WQE SGE. "
"num_sqe=%x max_nr_of_sg=%x",
send_wr->num_sge, qp->ipz_squeue.act_nr_of_sg);
return -EINVAL; /* invalid SG list length */
}
/* clear wqe header until sglist */
memset(wqe_p, 0, offsetof(struct ehca_wqe, u.ud_av.sg_list));
wqe_p->work_request_id = send_wr->wr_id;
switch (send_wr->opcode) {
case IB_WR_SEND:
case IB_WR_SEND_WITH_IMM:
wqe_p->optype = WQE_OPTYPE_SEND;
break;
case IB_WR_RDMA_WRITE:
case IB_WR_RDMA_WRITE_WITH_IMM:
wqe_p->optype = WQE_OPTYPE_RDMAWRITE;
break;
case IB_WR_RDMA_READ:
wqe_p->optype = WQE_OPTYPE_RDMAREAD;
break;
default:
ehca_gen_err("Invalid opcode=%x", send_wr->opcode);
return -EINVAL; /* invalid opcode */
}
wqe_p->wqef = (send_wr->opcode) & WQEF_HIGH_NIBBLE;
wqe_p->wr_flag = 0;
if (send_wr->send_flags & IB_SEND_SIGNALED)
wqe_p->wr_flag |= WQE_WRFLAG_REQ_SIGNAL_COM;
if (send_wr->opcode == IB_WR_SEND_WITH_IMM ||
send_wr->opcode == IB_WR_RDMA_WRITE_WITH_IMM) {
/* this might not work as long as HW does not support it */
wqe_p->immediate_data = be32_to_cpu(send_wr->imm_data);
wqe_p->wr_flag |= WQE_WRFLAG_IMM_DATA_PRESENT;
}
wqe_p->nr_of_data_seg = send_wr->num_sge;
switch (qp->qp_type) {
case IB_QPT_SMI:
case IB_QPT_GSI:
/* no break is intential here */
case IB_QPT_UD:
/* IB 1.2 spec C10-15 compliance */
if (send_wr->wr.ud.remote_qkey & 0x80000000)
remote_qkey = qp->qkey;
wqe_p->destination_qp_number = send_wr->wr.ud.remote_qpn << 8;
wqe_p->local_ee_context_qkey = remote_qkey;
if (!send_wr->wr.ud.ah) {
ehca_gen_err("wr.ud.ah is NULL. qp=%p", qp);
return -EINVAL;
}
my_av = container_of(send_wr->wr.ud.ah, struct ehca_av, ib_ah);
wqe_p->u.ud_av.ud_av = my_av->av;
/*
* omitted check of IB_SEND_INLINE
* since HW does not support it
*/
for (idx = 0; idx < send_wr->num_sge; idx++) {
wqe_p->u.ud_av.sg_list[idx].vaddr =
send_wr->sg_list[idx].addr;
wqe_p->u.ud_av.sg_list[idx].lkey =
send_wr->sg_list[idx].lkey;
wqe_p->u.ud_av.sg_list[idx].length =
send_wr->sg_list[idx].length;
} /* eof for idx */
if (qp->qp_type == IB_QPT_SMI ||
qp->qp_type == IB_QPT_GSI)
wqe_p->u.ud_av.ud_av.pmtu = 1;
if (qp->qp_type == IB_QPT_GSI) {
wqe_p->pkeyi = send_wr->wr.ud.pkey_index;
#ifdef DEBUG_GSI_SEND_WR
trace_send_wr_ud(send_wr);
#endif /* DEBUG_GSI_SEND_WR */
}
break;
case IB_QPT_UC:
if (send_wr->send_flags & IB_SEND_FENCE)
wqe_p->wr_flag |= WQE_WRFLAG_FENCE;
/* no break is intentional here */
case IB_QPT_RC:
/* TODO: atomic not implemented */
wqe_p->u.nud.remote_virtual_adress =
send_wr->wr.rdma.remote_addr;
wqe_p->u.nud.rkey = send_wr->wr.rdma.rkey;
/*
* omitted checking of IB_SEND_INLINE
* since HW does not support it
*/
dma_length = 0;
for (idx = 0; idx < send_wr->num_sge; idx++) {
wqe_p->u.nud.sg_list[idx].vaddr =
send_wr->sg_list[idx].addr;
wqe_p->u.nud.sg_list[idx].lkey =
send_wr->sg_list[idx].lkey;
wqe_p->u.nud.sg_list[idx].length =
send_wr->sg_list[idx].length;
dma_length += send_wr->sg_list[idx].length;
} /* eof idx */
wqe_p->u.nud.atomic_1st_op_dma_len = dma_length;
break;
default:
ehca_gen_err("Invalid qptype=%x", qp->qp_type);
return -EINVAL;
}
if (ehca_debug_level) {
ehca_gen_dbg("SEND WQE written into queue qp=%p ", qp);
ehca_dmp( wqe_p, 16*(6 + wqe_p->nr_of_data_seg), "send wqe");
}
return 0;
}
/* map_ib_wc_status converts raw cqe_status to ib_wc_status */
static inline void map_ib_wc_status(u32 cqe_status,
enum ib_wc_status *wc_status)
{
if (unlikely(cqe_status & WC_STATUS_ERROR_BIT)) {
switch (cqe_status & 0x3F) {
case 0x01:
case 0x21:
*wc_status = IB_WC_LOC_LEN_ERR;
break;
case 0x02:
case 0x22:
*wc_status = IB_WC_LOC_QP_OP_ERR;
break;
case 0x03:
case 0x23:
*wc_status = IB_WC_LOC_EEC_OP_ERR;
break;
case 0x04:
case 0x24:
*wc_status = IB_WC_LOC_PROT_ERR;
break;
case 0x05:
case 0x25:
*wc_status = IB_WC_WR_FLUSH_ERR;
break;
case 0x06:
*wc_status = IB_WC_MW_BIND_ERR;
break;
case 0x07: /* remote error - look into bits 20:24 */
switch ((cqe_status
& WC_STATUS_REMOTE_ERROR_FLAGS) >> 11) {
case 0x0:
/*
* PSN Sequence Error!
* couldn't find a matching status!
*/
*wc_status = IB_WC_GENERAL_ERR;
break;
case 0x1:
*wc_status = IB_WC_REM_INV_REQ_ERR;
break;
case 0x2:
*wc_status = IB_WC_REM_ACCESS_ERR;
break;
case 0x3:
*wc_status = IB_WC_REM_OP_ERR;
break;
case 0x4:
*wc_status = IB_WC_REM_INV_RD_REQ_ERR;
break;
}
break;
case 0x08:
*wc_status = IB_WC_RETRY_EXC_ERR;
break;
case 0x09:
*wc_status = IB_WC_RNR_RETRY_EXC_ERR;
break;
case 0x0A:
case 0x2D:
*wc_status = IB_WC_REM_ABORT_ERR;
break;
case 0x0B:
case 0x2E:
*wc_status = IB_WC_INV_EECN_ERR;
break;
case 0x0C:
case 0x2F:
*wc_status = IB_WC_INV_EEC_STATE_ERR;
break;
case 0x0D:
*wc_status = IB_WC_BAD_RESP_ERR;
break;
case 0x10:
/* WQE purged */
*wc_status = IB_WC_WR_FLUSH_ERR;
break;
default:
*wc_status = IB_WC_FATAL_ERR;
}
} else
*wc_status = IB_WC_SUCCESS;
}
int ehca_post_send(struct ib_qp *qp,
struct ib_send_wr *send_wr,
struct ib_send_wr **bad_send_wr)
{
struct ehca_qp *my_qp = container_of(qp, struct ehca_qp, ib_qp);
struct ib_send_wr *cur_send_wr;
struct ehca_wqe *wqe_p;
int wqe_cnt = 0;
int ret = 0;
unsigned long flags;
/* LOCK the QUEUE */
spin_lock_irqsave(&my_qp->spinlock_s, flags);
/* loop processes list of send reqs */
for (cur_send_wr = send_wr; cur_send_wr != NULL;
cur_send_wr = cur_send_wr->next) {
u64 start_offset = my_qp->ipz_squeue.current_q_offset;
/* get pointer next to free WQE */
wqe_p = ipz_qeit_get_inc(&my_qp->ipz_squeue);
if (unlikely(!wqe_p)) {
/* too many posted work requests: queue overflow */
if (bad_send_wr)
*bad_send_wr = cur_send_wr;
if (wqe_cnt == 0) {
ret = -ENOMEM;
ehca_err(qp->device, "Too many posted WQEs "
"qp_num=%x", qp->qp_num);
}
goto post_send_exit0;
}
/* write a SEND WQE into the QUEUE */
ret = ehca_write_swqe(my_qp, wqe_p, cur_send_wr);
/*
* if something failed,
* reset the free entry pointer to the start value
*/
if (unlikely(ret)) {
my_qp->ipz_squeue.current_q_offset = start_offset;
*bad_send_wr = cur_send_wr;
if (wqe_cnt == 0) {
ret = -EINVAL;
ehca_err(qp->device, "Could not write WQE "
"qp_num=%x", qp->qp_num);
}
goto post_send_exit0;
}
wqe_cnt++;
ehca_dbg(qp->device, "ehca_qp=%p qp_num=%x wqe_cnt=%d",
my_qp, qp->qp_num, wqe_cnt);
} /* eof for cur_send_wr */
post_send_exit0:
iosync(); /* serialize GAL register access */
hipz_update_sqa(my_qp, wqe_cnt);
spin_unlock_irqrestore(&my_qp->spinlock_s, flags);
return ret;
}
static int internal_post_recv(struct ehca_qp *my_qp,
struct ib_device *dev,
struct ib_recv_wr *recv_wr,
struct ib_recv_wr **bad_recv_wr)
{
struct ib_recv_wr *cur_recv_wr;
struct ehca_wqe *wqe_p;
int wqe_cnt = 0;
int ret = 0;
unsigned long flags;
if (unlikely(!HAS_RQ(my_qp))) {
ehca_err(dev, "QP has no RQ ehca_qp=%p qp_num=%x ext_type=%d",
my_qp, my_qp->real_qp_num, my_qp->ext_type);
return -ENODEV;
}
/* LOCK the QUEUE */
spin_lock_irqsave(&my_qp->spinlock_r, flags);
/* loop processes list of send reqs */
for (cur_recv_wr = recv_wr; cur_recv_wr != NULL;
cur_recv_wr = cur_recv_wr->next) {
u64 start_offset = my_qp->ipz_rqueue.current_q_offset;
/* get pointer next to free WQE */
wqe_p = ipz_qeit_get_inc(&my_qp->ipz_rqueue);
if (unlikely(!wqe_p)) {
/* too many posted work requests: queue overflow */
if (bad_recv_wr)
*bad_recv_wr = cur_recv_wr;
if (wqe_cnt == 0) {
ret = -ENOMEM;
ehca_err(dev, "Too many posted WQEs "
"qp_num=%x", my_qp->real_qp_num);
}
goto post_recv_exit0;
}
/* write a RECV WQE into the QUEUE */
ret = ehca_write_rwqe(&my_qp->ipz_rqueue, wqe_p, cur_recv_wr);
/*
* if something failed,
* reset the free entry pointer to the start value
*/
if (unlikely(ret)) {
my_qp->ipz_rqueue.current_q_offset = start_offset;
*bad_recv_wr = cur_recv_wr;
if (wqe_cnt == 0) {
ret = -EINVAL;
ehca_err(dev, "Could not write WQE "
"qp_num=%x", my_qp->real_qp_num);
}
goto post_recv_exit0;
}
wqe_cnt++;
ehca_dbg(dev, "ehca_qp=%p qp_num=%x wqe_cnt=%d",
my_qp, my_qp->real_qp_num, wqe_cnt);
} /* eof for cur_recv_wr */
post_recv_exit0:
iosync(); /* serialize GAL register access */
hipz_update_rqa(my_qp, wqe_cnt);
spin_unlock_irqrestore(&my_qp->spinlock_r, flags);
return ret;
}
int ehca_post_recv(struct ib_qp *qp,
struct ib_recv_wr *recv_wr,
struct ib_recv_wr **bad_recv_wr)
{
return internal_post_recv(container_of(qp, struct ehca_qp, ib_qp),
qp->device, recv_wr, bad_recv_wr);
}
int ehca_post_srq_recv(struct ib_srq *srq,
struct ib_recv_wr *recv_wr,
struct ib_recv_wr **bad_recv_wr)
{
return internal_post_recv(container_of(srq, struct ehca_qp, ib_srq),
srq->device, recv_wr, bad_recv_wr);
}
/*
* ib_wc_opcode table converts ehca wc opcode to ib
* Since we use zero to indicate invalid opcode, the actual ib opcode must
* be decremented!!!
*/
static const u8 ib_wc_opcode[255] = {
[0x01] = IB_WC_RECV+1,
[0x02] = IB_WC_RECV_RDMA_WITH_IMM+1,
[0x04] = IB_WC_BIND_MW+1,
[0x08] = IB_WC_FETCH_ADD+1,
[0x10] = IB_WC_COMP_SWAP+1,
[0x20] = IB_WC_RDMA_WRITE+1,
[0x40] = IB_WC_RDMA_READ+1,
[0x80] = IB_WC_SEND+1
};
/* internal function to poll one entry of cq */
static inline int ehca_poll_cq_one(struct ib_cq *cq, struct ib_wc *wc)
{
int ret = 0;
struct ehca_cq *my_cq = container_of(cq, struct ehca_cq, ib_cq);
struct ehca_cqe *cqe;
struct ehca_qp *my_qp;
int cqe_count = 0;
poll_cq_one_read_cqe:
cqe = (struct ehca_cqe *)
ipz_qeit_get_inc_valid(&my_cq->ipz_queue);
if (!cqe) {
ret = -EAGAIN;
ehca_dbg(cq->device, "Completion queue is empty ehca_cq=%p "
"cq_num=%x ret=%x", my_cq, my_cq->cq_number, ret);
goto poll_cq_one_exit0;
}
/* prevents loads being reordered across this point */
rmb();
cqe_count++;
if (unlikely(cqe->status & WC_STATUS_PURGE_BIT)) {
struct ehca_qp *qp=ehca_cq_get_qp(my_cq, cqe->local_qp_number);
int purgeflag;
unsigned long flags;
if (!qp) {
ehca_err(cq->device, "cq_num=%x qp_num=%x "
"could not find qp -> ignore cqe",
my_cq->cq_number, cqe->local_qp_number);
ehca_dmp(cqe, 64, "cq_num=%x qp_num=%x",
my_cq->cq_number, cqe->local_qp_number);
/* ignore this purged cqe */
goto poll_cq_one_read_cqe;
}
spin_lock_irqsave(&qp->spinlock_s, flags);
purgeflag = qp->sqerr_purgeflag;
spin_unlock_irqrestore(&qp->spinlock_s, flags);
if (purgeflag) {
ehca_dbg(cq->device, "Got CQE with purged bit qp_num=%x "
"src_qp=%x",
cqe->local_qp_number, cqe->remote_qp_number);
if (ehca_debug_level)
ehca_dmp(cqe, 64, "qp_num=%x src_qp=%x",
cqe->local_qp_number,
cqe->remote_qp_number);
/*
* ignore this to avoid double cqes of bad wqe
* that caused sqe and turn off purge flag
*/
qp->sqerr_purgeflag = 0;
goto poll_cq_one_read_cqe;
}
}
/* tracing cqe */
if (unlikely(ehca_debug_level)) {
ehca_dbg(cq->device,
"Received COMPLETION ehca_cq=%p cq_num=%x -----",
my_cq, my_cq->cq_number);
ehca_dmp(cqe, 64, "ehca_cq=%p cq_num=%x",
my_cq, my_cq->cq_number);
ehca_dbg(cq->device,
"ehca_cq=%p cq_num=%x -------------------------",
my_cq, my_cq->cq_number);
}
/* we got a completion! */
wc->wr_id = cqe->work_request_id;
/* eval ib_wc_opcode */
wc->opcode = ib_wc_opcode[cqe->optype]-1;
if (unlikely(wc->opcode == -1)) {
ehca_err(cq->device, "Invalid cqe->OPType=%x cqe->status=%x "
"ehca_cq=%p cq_num=%x",
cqe->optype, cqe->status, my_cq, my_cq->cq_number);
/* dump cqe for other infos */
ehca_dmp(cqe, 64, "ehca_cq=%p cq_num=%x",
my_cq, my_cq->cq_number);
/* update also queue adder to throw away this entry!!! */
goto poll_cq_one_exit0;
}
/* eval ib_wc_status */
if (unlikely(cqe->status & WC_STATUS_ERROR_BIT)) {
/* complete with errors */
map_ib_wc_status(cqe->status, &wc->status);
wc->vendor_err = wc->status;
} else
wc->status = IB_WC_SUCCESS;
read_lock(&ehca_qp_idr_lock);
my_qp = idr_find(&ehca_qp_idr, cqe->qp_token);
wc->qp = &my_qp->ib_qp;
read_unlock(&ehca_qp_idr_lock);
wc->byte_len = cqe->nr_bytes_transferred;
wc->pkey_index = cqe->pkey_index;
wc->slid = cqe->rlid;
wc->dlid_path_bits = cqe->dlid;
wc->src_qp = cqe->remote_qp_number;
wc->wc_flags = cqe->w_completion_flags;
wc->imm_data = cpu_to_be32(cqe->immediate_data);
wc->sl = cqe->service_level;
if (unlikely(wc->status != IB_WC_SUCCESS))
ehca_dbg(cq->device,
"ehca_cq=%p cq_num=%x WARNING unsuccessful cqe "
"OPType=%x status=%x qp_num=%x src_qp=%x wr_id=%lx "
"cqe=%p", my_cq, my_cq->cq_number, cqe->optype,
cqe->status, cqe->local_qp_number,
cqe->remote_qp_number, cqe->work_request_id, cqe);
poll_cq_one_exit0:
if (cqe_count > 0)
hipz_update_feca(my_cq, cqe_count);
return ret;
}
int ehca_poll_cq(struct ib_cq *cq, int num_entries, struct ib_wc *wc)
{
struct ehca_cq *my_cq = container_of(cq, struct ehca_cq, ib_cq);
int nr;
struct ib_wc *current_wc = wc;
int ret = 0;
unsigned long flags;
if (num_entries < 1) {
ehca_err(cq->device, "Invalid num_entries=%d ehca_cq=%p "
"cq_num=%x", num_entries, my_cq, my_cq->cq_number);
ret = -EINVAL;
goto poll_cq_exit0;
}
spin_lock_irqsave(&my_cq->spinlock, flags);
for (nr = 0; nr < num_entries; nr++) {
ret = ehca_poll_cq_one(cq, current_wc);
if (ret)
break;
current_wc++;
} /* eof for nr */
spin_unlock_irqrestore(&my_cq->spinlock, flags);
if (ret == -EAGAIN || !ret)
ret = nr;
poll_cq_exit0:
return ret;
}
IB: Return "maybe missed event" hint from ib_req_notify_cq() The semantics defined by the InfiniBand specification say that completion events are only generated when a completions is added to a completion queue (CQ) after completion notification is requested. In other words, this means that the following race is possible: while (CQ is not empty) ib_poll_cq(CQ); // new completion is added after while loop is exited ib_req_notify_cq(CQ); // no event is generated for the existing completion To close this race, the IB spec recommends doing another poll of the CQ after requesting notification. However, it is not always possible to arrange code this way (for example, we have found that NAPI for IPoIB cannot poll after requesting notification). Also, some hardware (eg Mellanox HCAs) actually will generate an event for completions added before the call to ib_req_notify_cq() -- which is allowed by the spec, since there's no way for any upper-layer consumer to know exactly when a completion was really added -- so the extra poll of the CQ is just a waste. Motivated by this, we add a new flag "IB_CQ_REPORT_MISSED_EVENTS" for ib_req_notify_cq() so that it can return a hint about whether the a completion may have been added before the request for notification. The return value of ib_req_notify_cq() is extended so: < 0 means an error occurred while requesting notification == 0 means notification was requested successfully, and if IB_CQ_REPORT_MISSED_EVENTS was passed in, then no events were missed and it is safe to wait for another event. > 0 is only returned if IB_CQ_REPORT_MISSED_EVENTS was passed in. It means that the consumer must poll the CQ again to make sure it is empty to avoid the race described above. We add a flag to enable this behavior rather than turning it on unconditionally, because checking for missed events may incur significant overhead for some low-level drivers, and consumers that don't care about the results of this test shouldn't be forced to pay for the test. Signed-off-by: Roland Dreier <rolandd@cisco.com>
2007-05-07 04:02:48 +00:00
int ehca_req_notify_cq(struct ib_cq *cq, enum ib_cq_notify_flags notify_flags)
{
struct ehca_cq *my_cq = container_of(cq, struct ehca_cq, ib_cq);
IB: Return "maybe missed event" hint from ib_req_notify_cq() The semantics defined by the InfiniBand specification say that completion events are only generated when a completions is added to a completion queue (CQ) after completion notification is requested. In other words, this means that the following race is possible: while (CQ is not empty) ib_poll_cq(CQ); // new completion is added after while loop is exited ib_req_notify_cq(CQ); // no event is generated for the existing completion To close this race, the IB spec recommends doing another poll of the CQ after requesting notification. However, it is not always possible to arrange code this way (for example, we have found that NAPI for IPoIB cannot poll after requesting notification). Also, some hardware (eg Mellanox HCAs) actually will generate an event for completions added before the call to ib_req_notify_cq() -- which is allowed by the spec, since there's no way for any upper-layer consumer to know exactly when a completion was really added -- so the extra poll of the CQ is just a waste. Motivated by this, we add a new flag "IB_CQ_REPORT_MISSED_EVENTS" for ib_req_notify_cq() so that it can return a hint about whether the a completion may have been added before the request for notification. The return value of ib_req_notify_cq() is extended so: < 0 means an error occurred while requesting notification == 0 means notification was requested successfully, and if IB_CQ_REPORT_MISSED_EVENTS was passed in, then no events were missed and it is safe to wait for another event. > 0 is only returned if IB_CQ_REPORT_MISSED_EVENTS was passed in. It means that the consumer must poll the CQ again to make sure it is empty to avoid the race described above. We add a flag to enable this behavior rather than turning it on unconditionally, because checking for missed events may incur significant overhead for some low-level drivers, and consumers that don't care about the results of this test shouldn't be forced to pay for the test. Signed-off-by: Roland Dreier <rolandd@cisco.com>
2007-05-07 04:02:48 +00:00
int ret = 0;
IB: Return "maybe missed event" hint from ib_req_notify_cq() The semantics defined by the InfiniBand specification say that completion events are only generated when a completions is added to a completion queue (CQ) after completion notification is requested. In other words, this means that the following race is possible: while (CQ is not empty) ib_poll_cq(CQ); // new completion is added after while loop is exited ib_req_notify_cq(CQ); // no event is generated for the existing completion To close this race, the IB spec recommends doing another poll of the CQ after requesting notification. However, it is not always possible to arrange code this way (for example, we have found that NAPI for IPoIB cannot poll after requesting notification). Also, some hardware (eg Mellanox HCAs) actually will generate an event for completions added before the call to ib_req_notify_cq() -- which is allowed by the spec, since there's no way for any upper-layer consumer to know exactly when a completion was really added -- so the extra poll of the CQ is just a waste. Motivated by this, we add a new flag "IB_CQ_REPORT_MISSED_EVENTS" for ib_req_notify_cq() so that it can return a hint about whether the a completion may have been added before the request for notification. The return value of ib_req_notify_cq() is extended so: < 0 means an error occurred while requesting notification == 0 means notification was requested successfully, and if IB_CQ_REPORT_MISSED_EVENTS was passed in, then no events were missed and it is safe to wait for another event. > 0 is only returned if IB_CQ_REPORT_MISSED_EVENTS was passed in. It means that the consumer must poll the CQ again to make sure it is empty to avoid the race described above. We add a flag to enable this behavior rather than turning it on unconditionally, because checking for missed events may incur significant overhead for some low-level drivers, and consumers that don't care about the results of this test shouldn't be forced to pay for the test. Signed-off-by: Roland Dreier <rolandd@cisco.com>
2007-05-07 04:02:48 +00:00
switch (notify_flags & IB_CQ_SOLICITED_MASK) {
case IB_CQ_SOLICITED:
hipz_set_cqx_n0(my_cq, 1);
break;
case IB_CQ_NEXT_COMP:
hipz_set_cqx_n1(my_cq, 1);
break;
default:
return -EINVAL;
}
IB: Return "maybe missed event" hint from ib_req_notify_cq() The semantics defined by the InfiniBand specification say that completion events are only generated when a completions is added to a completion queue (CQ) after completion notification is requested. In other words, this means that the following race is possible: while (CQ is not empty) ib_poll_cq(CQ); // new completion is added after while loop is exited ib_req_notify_cq(CQ); // no event is generated for the existing completion To close this race, the IB spec recommends doing another poll of the CQ after requesting notification. However, it is not always possible to arrange code this way (for example, we have found that NAPI for IPoIB cannot poll after requesting notification). Also, some hardware (eg Mellanox HCAs) actually will generate an event for completions added before the call to ib_req_notify_cq() -- which is allowed by the spec, since there's no way for any upper-layer consumer to know exactly when a completion was really added -- so the extra poll of the CQ is just a waste. Motivated by this, we add a new flag "IB_CQ_REPORT_MISSED_EVENTS" for ib_req_notify_cq() so that it can return a hint about whether the a completion may have been added before the request for notification. The return value of ib_req_notify_cq() is extended so: < 0 means an error occurred while requesting notification == 0 means notification was requested successfully, and if IB_CQ_REPORT_MISSED_EVENTS was passed in, then no events were missed and it is safe to wait for another event. > 0 is only returned if IB_CQ_REPORT_MISSED_EVENTS was passed in. It means that the consumer must poll the CQ again to make sure it is empty to avoid the race described above. We add a flag to enable this behavior rather than turning it on unconditionally, because checking for missed events may incur significant overhead for some low-level drivers, and consumers that don't care about the results of this test shouldn't be forced to pay for the test. Signed-off-by: Roland Dreier <rolandd@cisco.com>
2007-05-07 04:02:48 +00:00
if (notify_flags & IB_CQ_REPORT_MISSED_EVENTS) {
unsigned long spl_flags;
IB: Return "maybe missed event" hint from ib_req_notify_cq() The semantics defined by the InfiniBand specification say that completion events are only generated when a completions is added to a completion queue (CQ) after completion notification is requested. In other words, this means that the following race is possible: while (CQ is not empty) ib_poll_cq(CQ); // new completion is added after while loop is exited ib_req_notify_cq(CQ); // no event is generated for the existing completion To close this race, the IB spec recommends doing another poll of the CQ after requesting notification. However, it is not always possible to arrange code this way (for example, we have found that NAPI for IPoIB cannot poll after requesting notification). Also, some hardware (eg Mellanox HCAs) actually will generate an event for completions added before the call to ib_req_notify_cq() -- which is allowed by the spec, since there's no way for any upper-layer consumer to know exactly when a completion was really added -- so the extra poll of the CQ is just a waste. Motivated by this, we add a new flag "IB_CQ_REPORT_MISSED_EVENTS" for ib_req_notify_cq() so that it can return a hint about whether the a completion may have been added before the request for notification. The return value of ib_req_notify_cq() is extended so: < 0 means an error occurred while requesting notification == 0 means notification was requested successfully, and if IB_CQ_REPORT_MISSED_EVENTS was passed in, then no events were missed and it is safe to wait for another event. > 0 is only returned if IB_CQ_REPORT_MISSED_EVENTS was passed in. It means that the consumer must poll the CQ again to make sure it is empty to avoid the race described above. We add a flag to enable this behavior rather than turning it on unconditionally, because checking for missed events may incur significant overhead for some low-level drivers, and consumers that don't care about the results of this test shouldn't be forced to pay for the test. Signed-off-by: Roland Dreier <rolandd@cisco.com>
2007-05-07 04:02:48 +00:00
spin_lock_irqsave(&my_cq->spinlock, spl_flags);
ret = ipz_qeit_is_valid(&my_cq->ipz_queue);
spin_unlock_irqrestore(&my_cq->spinlock, spl_flags);
}
return ret;
}