[PATCH AUTOSEL 4.14 227/371] qed: iWARP - Use READ_ONCE and smp_store_release to access ep->state

Sasha Levin
2020-01-16T17:27:55Z

From: Michal Kalderon <michal.kalderon@marvell.com>

[ Upstream commit 6117561e1bb30b2fe7f51e1961f34dbedd0bec8a ]

Destroy QP waits for it's ep object state to be set to CLOSED
before proceeding. ep->state can be updated from a different
context. Add smp_store_release/READ_ONCE to synchronize.

Fixes: fc4c6065e661 ("qed: iWARP implement disconnect flows")
Signed-off-by: Ariel Elior <ariel.elior@marvell.com>
Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/qlogic/qed/qed_iwarp.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qed/qed_iwarp.c b/drivers/net/ethernet/qlogic/qed/qed_iwarp.c
index bb09f5a9846f..38d0f62bf037 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_iwarp.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_iwarp.c
@@ -509,7 +509,8 @@ int qed_iwarp_destroy_qp(struct qed_hwfn *p_hwfn, struct qed_rdma_qp *qp)

/* Make sure ep is closed before returning and freeing memory. */
if (ep) {
- while (ep->state != QED_IWARP_EP_CLOSED && wait_count++ < 200)
+ while (READ_ONCE(ep->state) != QED_IWARP_EP_CLOSED &&
+ wait_count++ < 200)
msleep(100);

if (ep->state != QED_IWARP_EP_CLOSED)
@@ -991,8 +992,6 @@ qed_iwarp_mpa_complete(struct qed_hwfn *p_hwfn,

params.ep_context = ep;

- ep->state = QED_IWARP_EP_CLOSED;
-
switch (fw_return_code) {
case RDMA_RETURN_OK:
ep->qp->max_rd_atomic_req = ep->cm_info.ord;
@@ -1052,6 +1051,10 @@ qed_iwarp_mpa_complete(struct qed_hwfn *p_hwfn,
break;
}

+ if (fw_return_code != RDMA_RETURN_OK)
+ /* paired with READ_ONCE in destroy_qp */
+ smp_store_release(&ep->state, QED_IWARP_EP_CLOSED);
+
ep->event_cb(ep->cb_context, &params);

/* on passive side, if there is no associated QP (REJECT) we need to
@@ -2069,7 +2072,9 @@ void qed_iwarp_qp_in_error(struct qed_hwfn *p_hwfn,
params.status = (fw_return_code == IWARP_QP_IN_ERROR_GOOD_CLOSE) ?
0 : -ECONNRESET;

- ep->state = QED_IWARP_EP_CLOSED;
+ /* paired with READ_ONCE in destroy_qp */
+ smp_store_release(&ep->state, QED_IWARP_EP_CLOSED);
+
spin_lock_bh(&p_hwfn->p_rdma_info->iwarp.iw_lock);
list_del(&ep->list_entry);
spin_unlock_bh(&p_hwfn->p_rdma_info->iwarp.iw_lock);
@@ -2157,7 +2162,8 @@ qed_iwarp_tcp_connect_unsuccessful(struct qed_hwfn *p_hwfn,
params.event = QED_IWARP_EVENT_ACTIVE_COMPLETE;
params.ep_context = ep;
params.cm_info = &ep->cm_info;
- ep->state = QED_IWARP_EP_CLOSED;
+ /* paired with READ_ONCE in destroy_qp */
+ smp_store_release(&ep->state, QED_IWARP_EP_CLOSED);

switch (fw_return_code) {
case IWARP_CONN_ERROR_TCP_CONNECT_INVALID_PACKET:
--
2.20.1