6.5-stable review patch. If anyone has any objections, please let me know.
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From: Selvin Xavier selvin.xavier@broadcom.com
commit 9fc5f9a92fe6897dbed7b9295b234cb7e3cc9d11 upstream.
Flag that indicate control path command completion should be cleared only after copying the command response data. As soon as the is_in_used flag is clear, the waiting thread can proceed with wrong response data. This wrong data is causing multiple issues like wrong lkey used in data traffic and wrong AH Id etc.
Use a memory barrier to ensure that the response data is copied and visible to the process waiting on a different cpu core before clearing the is_in_used flag.
Clear the is_in_used after copying the command response.
Fixes: bcfee4ce3e01 ("RDMA/bnxt_re: remove redundant cmdq_bitmap") Signed-off-by: Saravanan Vajravel saravanan.vajravel@broadcom.com Signed-off-by: Selvin Xavier selvin.xavier@broadcom.com Link: https://lore.kernel.org/r/1695199280-13520-2-git-send-email-selvin.xavier@br... Signed-off-by: Leon Romanovsky leon@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
--- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c +++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c @@ -664,7 +664,6 @@ static int bnxt_qplib_process_qp_event(s blocked = cookie & RCFW_CMD_IS_BLOCKING; cookie &= RCFW_MAX_COOKIE_VALUE; crsqe = &rcfw->crsqe_tbl[cookie]; - crsqe->is_in_used = false;
if (WARN_ONCE(test_bit(FIRMWARE_STALL_DETECTED, &rcfw->cmdq.flags), @@ -680,8 +679,14 @@ static int bnxt_qplib_process_qp_event(s atomic_dec(&rcfw->timeout_send);
if (crsqe->is_waiter_alive) { - if (crsqe->resp) + if (crsqe->resp) { memcpy(crsqe->resp, qp_event, sizeof(*qp_event)); + /* Insert write memory barrier to ensure that + * response data is copied before clearing the + * flags + */ + smp_wmb(); + } if (!blocked) wait_cmds++; } @@ -693,6 +698,8 @@ static int bnxt_qplib_process_qp_event(s if (!is_waiter_alive) crsqe->resp = NULL;
+ crsqe->is_in_used = false; + hwq->cons += req_size;
/* This is a case to handle below scenario -