IB/core: add max_send_sge and max_recv_sge attributes

This patch replaces the ib_device_attr.max_sge with max_send_sge and
max_recv_sge. It allows ulps to take advantage of devices that have very
different send and recv sge depths.  For example cxgb4 has a max_recv_sge
of 4, yet a max_send_sge of 16.  Splitting out these attributes allows
much more efficient use of the SQ for cxgb4 with ulps that use the RDMA_RW
API. Consider a large RDMA WRITE that has 16 scattergather entries.
With max_sge of 4, the ulp would send 4 WRITE WRs, but with max_sge of
16, it can be done with 1 WRITE WR.

Acked-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
Acked-by: Shiraz Saleem <shiraz.saleem@intel.com>
Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/infiniband/hw/hfi1/verbs.c b/drivers/infiniband/hw/hfi1/verbs.c
index 08991874c0e2..b7c75b63f887 100644
--- a/drivers/infiniband/hw/hfi1/verbs.c
+++ b/drivers/infiniband/hw/hfi1/verbs.c
@@ -1410,7 +1410,8 @@ static void hfi1_fill_device_attr(struct hfi1_devdata *dd)
 	rdi->dparms.props.max_fast_reg_page_list_len = UINT_MAX;
 	rdi->dparms.props.max_qp = hfi1_max_qps;
 	rdi->dparms.props.max_qp_wr = hfi1_max_qp_wrs;
-	rdi->dparms.props.max_sge = hfi1_max_sges;
+	rdi->dparms.props.max_send_sge = hfi1_max_sges;
+	rdi->dparms.props.max_recv_sge = hfi1_max_sges;
 	rdi->dparms.props.max_sge_rd = hfi1_max_sges;
 	rdi->dparms.props.max_cq = hfi1_max_cqs;
 	rdi->dparms.props.max_ah = hfi1_max_ahs;