IB/{rdmavt, qib, hfi1}: Convert to new completion API

Convert all completions to use the new completion routine that
fixes a race between post send and completion where fields from
a SWQE can be read after SWQE has been freed.

This patch also addresses issues reported in
https://marc.info/?l=linux-kernel&m=155656897409107&w=2.

The reserved operation path has no need for any barrier.

The barrier for the other path is addressed by the
smp_load_acquire() barrier.

Cc: Andrea Parri <andrea.parri@amarulasolutions.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This commit is contained in:
Mike Marciniszyn 2019-06-13 08:30:52 -04:00 committed by Doug Ledford
parent f56044d686
commit 4a9ceb7dba
4 changed files with 17 additions and 102 deletions

View File

@ -1819,23 +1819,14 @@ void hfi1_rc_send_complete(struct rvt_qp *qp, struct hfi1_opa_header *opah)
}
while (qp->s_last != qp->s_acked) {
u32 s_last;
wqe = rvt_get_swqe_ptr(qp, qp->s_last);
if (cmp_psn(wqe->lpsn, qp->s_sending_psn) >= 0 &&
cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)
break;
trdma_clean_swqe(qp, wqe);
rvt_qp_wqe_unreserve(qp, wqe);
s_last = qp->s_last;
trace_hfi1_qp_send_completion(qp, wqe, s_last);
if (++s_last >= qp->s_size)
s_last = 0;
qp->s_last = s_last;
/* see post_send() */
barrier();
rvt_put_qp_swqe(qp, wqe);
rvt_qp_swqe_complete(qp,
trace_hfi1_qp_send_completion(qp, wqe, qp->s_last);
rvt_qp_complete_swqe(qp,
wqe,
ib_hfi1_wc_opcode[wqe->wr.opcode],
IB_WC_SUCCESS);
@ -1879,19 +1870,10 @@ struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
trace_hfi1_rc_completion(qp, wqe->lpsn);
if (cmp_psn(wqe->lpsn, qp->s_sending_psn) < 0 ||
cmp_psn(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
u32 s_last;
trdma_clean_swqe(qp, wqe);
rvt_put_qp_swqe(qp, wqe);
rvt_qp_wqe_unreserve(qp, wqe);
s_last = qp->s_last;
trace_hfi1_qp_send_completion(qp, wqe, s_last);
if (++s_last >= qp->s_size)
s_last = 0;
qp->s_last = s_last;
/* see post_send() */
barrier();
rvt_qp_swqe_complete(qp,
trace_hfi1_qp_send_completion(qp, wqe, qp->s_last);
rvt_qp_complete_swqe(qp,
wqe,
ib_hfi1_wc_opcode[wqe->wr.opcode],
IB_WC_SUCCESS);

View File

@ -921,20 +921,11 @@ void qib_rc_send_complete(struct rvt_qp *qp, struct ib_header *hdr)
rvt_add_retry_timer(qp);
while (qp->s_last != qp->s_acked) {
u32 s_last;
wqe = rvt_get_swqe_ptr(qp, qp->s_last);
if (qib_cmp24(wqe->lpsn, qp->s_sending_psn) >= 0 &&
qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) <= 0)
break;
s_last = qp->s_last;
if (++s_last >= qp->s_size)
s_last = 0;
qp->s_last = s_last;
/* see post_send() */
barrier();
rvt_put_qp_swqe(qp, wqe);
rvt_qp_swqe_complete(qp,
rvt_qp_complete_swqe(qp,
wqe,
ib_qib_wc_opcode[wqe->wr.opcode],
IB_WC_SUCCESS);
@ -972,21 +963,12 @@ static struct rvt_swqe *do_rc_completion(struct rvt_qp *qp,
* is finished.
*/
if (qib_cmp24(wqe->lpsn, qp->s_sending_psn) < 0 ||
qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) > 0) {
u32 s_last;
rvt_put_qp_swqe(qp, wqe);
s_last = qp->s_last;
if (++s_last >= qp->s_size)
s_last = 0;
qp->s_last = s_last;
/* see post_send() */
barrier();
rvt_qp_swqe_complete(qp,
qib_cmp24(qp->s_sending_psn, qp->s_sending_hpsn) > 0)
rvt_qp_complete_swqe(qp,
wqe,
ib_qib_wc_opcode[wqe->wr.opcode],
IB_WC_SUCCESS);
} else
else
this_cpu_inc(*ibp->rvp.rc_delayed_comp);
qp->s_retry = qp->s_retry_cnt;

View File

@ -1853,10 +1853,9 @@ static inline int rvt_qp_is_avail(
/* see rvt_qp_wqe_unreserve() */
smp_mb__before_atomic();
reserved_used = atomic_read(&qp->s_reserved_used);
if (unlikely(reserved_op)) {
/* see rvt_qp_wqe_unreserve() */
smp_mb__before_atomic();
reserved_used = atomic_read(&qp->s_reserved_used);
if (reserved_used >= rdi->dparms.reserved_operations)
return -ENOMEM;
return 0;
@ -1864,14 +1863,13 @@ static inline int rvt_qp_is_avail(
/* non-reserved operations */
if (likely(qp->s_avail))
return 0;
slast = READ_ONCE(qp->s_last);
/* See rvt_qp_complete_swqe() */
slast = smp_load_acquire(&qp->s_last);
if (qp->s_head >= slast)
avail = qp->s_size - (qp->s_head - slast);
else
avail = slast - qp->s_head;
/* see rvt_qp_wqe_unreserve() */
smp_mb__before_atomic();
reserved_used = atomic_read(&qp->s_reserved_used);
avail = avail - 1 -
(rdi->dparms.reserved_operations - reserved_used);
@ -2664,27 +2662,16 @@ void rvt_send_complete(struct rvt_qp *qp, struct rvt_swqe *wqe,
enum ib_wc_status status)
{
u32 old_last, last;
struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
struct rvt_dev_info *rdi;
if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_OR_FLUSH_SEND))
return;
rdi = ib_to_rvt(qp->ibqp.device);
last = qp->s_last;
old_last = last;
trace_rvt_qp_send_completion(qp, wqe, last);
if (++last >= qp->s_size)
last = 0;
trace_rvt_qp_send_completion(qp, wqe, last);
qp->s_last = last;
/* See post_send() */
barrier();
rvt_put_qp_swqe(qp, wqe);
rvt_qp_swqe_complete(qp,
wqe,
rdi->wc_opcode[wqe->wr.opcode],
status);
old_last = qp->s_last;
trace_rvt_qp_send_completion(qp, wqe, old_last);
last = rvt_qp_complete_swqe(qp, wqe, rdi->wc_opcode[wqe->wr.opcode],
status);
if (qp->s_acked == old_last)
qp->s_acked = last;
if (qp->s_cur == old_last)

View File

@ -565,42 +565,6 @@ static inline void rvt_qp_wqe_unreserve(
extern const enum ib_wc_opcode ib_rvt_wc_opcode[];
/**
* rvt_qp_swqe_complete() - insert send completion
* @qp - the qp
* @wqe - the send wqe
* @status - completion status
*
* Insert a send completion into the completion
* queue if the qp indicates it should be done.
*
* See IBTA 10.7.3.1 for info on completion
* control.
*/
static inline void rvt_qp_swqe_complete(
struct rvt_qp *qp,
struct rvt_swqe *wqe,
enum ib_wc_opcode opcode,
enum ib_wc_status status)
{
if (unlikely(wqe->wr.send_flags & RVT_SEND_RESERVE_USED))
return;
if (!(qp->s_flags & RVT_S_SIGNAL_REQ_WR) ||
(wqe->wr.send_flags & IB_SEND_SIGNALED) ||
status != IB_WC_SUCCESS) {
struct ib_wc wc;
memset(&wc, 0, sizeof(wc));
wc.wr_id = wqe->wr.wr_id;
wc.status = status;
wc.opcode = opcode;
wc.qp = &qp->ibqp;
wc.byte_len = wqe->length;
rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.send_cq), &wc,
status != IB_WC_SUCCESS);
}
}
/*
* Compare the lower 24 bits of the msn values.
* Returns an integer <, ==, or > than zero.