[PATCH 5.10 252/717] RDMA/hns: Bugfix for calculation of extended sge

From: Greg Kroah-Hartman
Date: Mon Dec 28 2020 - 10:01:47 EST


From: Yangyang Li <liyangyang20@xxxxxxxxxx>

[ Upstream commit d34895c319faa1e0fc1a48c3b06bba6a8a39ba44 ]

Page alignment is required when setting the number of extended sge
according to the hardware's achivement. If the space of needed extended
sge is greater than one page, the roundup_pow_of_two() can ensure
that. But if the needed extended sge isn't 0 and can not be filled in a
whole page, the driver should align it specifically.

Fixes: 54d6638765b0 ("RDMA/hns: Optimize WQE buffer size calculating process")
Link: https://lore.kernel.org/r/1606558959-48510-3-git-send-email-liweihang@xxxxxxxxxx
Signed-off-by: Yangyang Li <liyangyang20@xxxxxxxxxx>
Signed-off-by: Weihang Li <liweihang@xxxxxxxxxx>
Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/infiniband/hw/hns/hns_roce_qp.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/hns/hns_roce_qp.c b/drivers/infiniband/hw/hns/hns_roce_qp.c
index 6c081dd985fc9..71ea8fd9041b9 100644
--- a/drivers/infiniband/hw/hns/hns_roce_qp.c
+++ b/drivers/infiniband/hw/hns/hns_roce_qp.c
@@ -432,7 +432,12 @@ static int set_extend_sge_param(struct hns_roce_dev *hr_dev, u32 sq_wqe_cnt,
}

hr_qp->sge.sge_shift = HNS_ROCE_SGE_SHIFT;
- hr_qp->sge.sge_cnt = cnt;
+
+ /* If the number of extended sge is not zero, they MUST use the
+ * space of HNS_HW_PAGE_SIZE at least.
+ */
+ hr_qp->sge.sge_cnt = cnt ?
+ max(cnt, (u32)HNS_HW_PAGE_SIZE / HNS_ROCE_SGE_SIZE) : 0;

return 0;
}
--
2.27.0