IB/mlx5: Call io_stop_wc() after writing to WC MMIO

This new function is defined only on ARM and serves to guarantee a barrier
in the WC operation. The barrier means that another run of this loop will
not combine with the stores this loop created.

On x86 this is happening implicitly because of the spin_unlock().

Link: https://lore.kernel.org/r/0-v1-c5dade92f363+11-mlx5_io_stop_wc_jgg@nvidia.com
Suggested-by: Pavel Shamis <Pavel.Shamis@arm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
This commit is contained in:
Jason Gunthorpe 2022-07-29 13:33:38 -03:00 committed by Leon Romanovsky
parent 568035b01c
commit 19d6214ad6

View File

@ -152,6 +152,7 @@ static int post_send_nop(struct mlx5_ib_dev *dev, struct ib_qp *ibqp, u64 wr_id,
for (i = 0; i < 8; i++)
mlx5_write64(&mmio_wqe[i * 2],
bf->bfreg->map + bf->offset + i * 8);
io_stop_wc();
bf->offset ^= bf->buf_size;