The smp_read_barrier_depends() does nothing at all except on DEC Alpha,
and no current DEC Alpha systems use Infiniband:
lkml.kernel.org/r/
20171023085921.jwbntptn6ictbnvj@tower
This commit therefore makes Infiniband depend on !ALPHA and removes
the now-ineffective invocations of smp_read_barrier_depends() from
the InfiniBand driver.
Please note that this patch should not be construed as my saying that
InfiniBand's memory ordering is correct, but rather that this patch does
not in any way affect InfiniBand's correctness. In other words, the
result of applying this patch is bug-for-bug compatible with the original.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: <linux-rdma@vger.kernel.org>
Cc: <linux-alpha@vger.kernel.org>
[ paulmck: Removed drivers/dma/ioat/dma.c per Jason Gunthorpe's feedback. ]
Acked-by: Jason Gunthorpe <jgg@mellanox.com>
depends on NET
depends on INET
depends on m || IPV6 != m
+ depends on !ALPHA
select IRQ_POLL
---help---
Core support for InfiniBand (IB). Make sure to also select
if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
goto bail;
/* We are in the error state, flush the work request. */
- smp_read_barrier_depends(); /* see post_one_send() */
if (qp->s_last == READ_ONCE(qp->s_head))
goto bail;
/* If DMAs are in progress, we can't flush immediately. */
newreq = 0;
if (qp->s_cur == qp->s_tail) {
/* Check if send work queue is empty. */
- smp_read_barrier_depends(); /* see post_one_send() */
if (qp->s_tail == READ_ONCE(qp->s_head)) {
clear_ahg(qp);
goto bail;
}
/* Ensure s_rdma_ack_cnt changes are committed */
- smp_read_barrier_depends();
if (qp->s_rdma_ack_cnt) {
hfi1_queue_rc_ack(qp, is_fecn);
return;
trace_hfi1_ack(qp, psn);
/* Ignore invalid responses. */
- smp_read_barrier_depends(); /* see post_one_send */
if (cmp_psn(psn, READ_ONCE(qp->s_next_psn)) >= 0)
goto ack_done;
sqp->s_flags |= RVT_S_BUSY;
again:
- smp_read_barrier_depends(); /* see post_one_send() */
if (sqp->s_last == READ_ONCE(sqp->s_head))
goto clr_busy;
wqe = rvt_get_swqe_ptr(sqp, sqp->s_last);
static inline struct sdma_txreq *get_txhead(struct sdma_engine *sde)
{
- smp_read_barrier_depends(); /* see sdma_update_tail() */
return sde->tx_ring[sde->tx_head & sde->sdma_mask];
}
if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
goto bail;
/* We are in the error state, flush the work request. */
- smp_read_barrier_depends(); /* see post_one_send() */
if (qp->s_last == READ_ONCE(qp->s_head))
goto bail;
/* If DMAs are in progress, we can't flush immediately. */
RVT_PROCESS_NEXT_SEND_OK))
goto bail;
/* Check if send work queue is empty. */
- smp_read_barrier_depends(); /* see post_one_send() */
if (qp->s_cur == READ_ONCE(qp->s_head)) {
clear_ahg(qp);
goto bail;
if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
goto bail;
/* We are in the error state, flush the work request. */
- smp_read_barrier_depends(); /* see post_one_send */
if (qp->s_last == READ_ONCE(qp->s_head))
goto bail;
/* If DMAs are in progress, we can't flush immediately. */
}
/* see post_one_send() */
- smp_read_barrier_depends();
if (qp->s_cur == READ_ONCE(qp->s_head))
goto bail;
if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
goto bail;
/* We are in the error state, flush the work request. */
- smp_read_barrier_depends(); /* see post_one_send() */
if (qp->s_last == READ_ONCE(qp->s_head))
goto bail;
/* If DMAs are in progress, we can't flush immediately. */
newreq = 0;
if (qp->s_cur == qp->s_tail) {
/* Check if send work queue is empty. */
- smp_read_barrier_depends(); /* see post_one_send() */
if (qp->s_tail == READ_ONCE(qp->s_head))
goto bail;
/*
goto ack_done;
/* Ignore invalid responses. */
- smp_read_barrier_depends(); /* see post_one_send */
if (qib_cmp24(psn, READ_ONCE(qp->s_next_psn)) >= 0)
goto ack_done;
sqp->s_flags |= RVT_S_BUSY;
again:
- smp_read_barrier_depends(); /* see post_one_send() */
if (sqp->s_last == READ_ONCE(sqp->s_head))
goto clr_busy;
wqe = rvt_get_swqe_ptr(sqp, sqp->s_last);
if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
goto bail;
/* We are in the error state, flush the work request. */
- smp_read_barrier_depends(); /* see post_one_send() */
if (qp->s_last == READ_ONCE(qp->s_head))
goto bail;
/* If DMAs are in progress, we can't flush immediately. */
RVT_PROCESS_NEXT_SEND_OK))
goto bail;
/* Check if send work queue is empty. */
- smp_read_barrier_depends(); /* see post_one_send() */
if (qp->s_cur == READ_ONCE(qp->s_head))
goto bail;
/*
if (!(ib_rvt_state_ops[qp->state] & RVT_FLUSH_SEND))
goto bail;
/* We are in the error state, flush the work request. */
- smp_read_barrier_depends(); /* see post_one_send */
if (qp->s_last == READ_ONCE(qp->s_head))
goto bail;
/* If DMAs are in progress, we can't flush immediately. */
}
/* see post_one_send() */
- smp_read_barrier_depends();
if (qp->s_cur == READ_ONCE(qp->s_head))
goto bail;
/* non-reserved operations */
if (likely(qp->s_avail))
return 0;
- smp_read_barrier_depends(); /* see rc.c */
slast = READ_ONCE(qp->s_last);
if (qp->s_head >= slast)
avail = qp->s_size - (qp->s_head - slast);