IB/mlx4: Fix creation of kernel QP with max number of send s/g entries
When creating a kernel QP where the consumer asked for a send queue
with lots of scatter/gater entries, set_kernel_sq_size() incorrectly
returned an error if the send queue stride is larger than the
hardware's maximum send work request descriptor size. This is not a
problem; the only issue is to make sure that the actual descriptors
used do not overflow the maximum descriptor size, so check this instead.
Clamp the returned max_send_sge value to be no bigger than what
query_device returns for the max_sge to avoid confusing hapless users,
even if the hardware is capable of handling a few more s/g entries.
This bug caused NFS/RDMA mounts to fail when the server adapter used
the mlx4 driver.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index cec030e..a80df22 100644
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -333,6 +333,9 @@
cap->max_inline_data + sizeof (struct mlx4_wqe_inline_seg)) +
send_wqe_overhead(type, qp->flags);
+ if (s > dev->dev->caps.max_sq_desc_sz)
+ return -EINVAL;
+
/*
* Hermon supports shrinking WQEs, such that a single work
* request can include multiple units of 1 << wqe_shift. This
@@ -372,9 +375,6 @@
qp->sq.wqe_shift = ilog2(roundup_pow_of_two(s));
for (;;) {
- if (1 << qp->sq.wqe_shift > dev->dev->caps.max_sq_desc_sz)
- return -EINVAL;
-
qp->sq_max_wqes_per_wr = DIV_ROUND_UP(s, 1U << qp->sq.wqe_shift);
/*
@@ -395,7 +395,8 @@
++qp->sq.wqe_shift;
}
- qp->sq.max_gs = ((qp->sq_max_wqes_per_wr << qp->sq.wqe_shift) -
+ qp->sq.max_gs = (min(dev->dev->caps.max_sq_desc_sz,
+ (qp->sq_max_wqes_per_wr << qp->sq.wqe_shift)) -
send_wqe_overhead(type, qp->flags)) /
sizeof (struct mlx4_wqe_data_seg);
@@ -411,7 +412,9 @@
cap->max_send_wr = qp->sq.max_post =
(qp->sq.wqe_cnt - qp->sq_spare_wqes) / qp->sq_max_wqes_per_wr;
- cap->max_send_sge = qp->sq.max_gs;
+ cap->max_send_sge = min(qp->sq.max_gs,
+ min(dev->dev->caps.max_sq_sg,
+ dev->dev->caps.max_rq_sg));
/* We don't support inline sends for kernel QPs (yet) */
cap->max_inline_data = 0;