From b0ffeb537f3a726931d962ab6d03e34a2f070ea4 Mon Sep 17 00:00:00 2001 From: Slava Shwartsman Date: Sun, 3 Jul 2016 15:28:19 +0300 Subject: [PATCH] IB/mlx5: Fix iteration overrun in GSI qps Number of outstanding_pi may overflow and as a result may indicate that there are no elements in the queue. The effect of doing this is that the MAD layer will get stuck waiting for completions. The MAD layer will think that the QP is full - because it didn't receive these completions. This fix changes it so the outstanding_pi number is increased with 32-bit wraparound and is not limited to max_send_wr so that the difference between outstanding_pi and outstanding_ci will really indicate the number of outstanding completions. Cc: Stable Fixes: ea6dc2036224 ('IB/mlx5: Reorder GSI completions') Signed-off-by: Slava Shwartsman Signed-off-by: Leon Romanovsky Reviewed-by: Haggai Eran Reviewed-by: Sagi Grimberg Signed-off-by: Doug Ledford --- drivers/infiniband/hw/mlx5/gsi.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/gsi.c b/drivers/infiniband/hw/mlx5/gsi.c index 53e03c8ede79..79e6309460dc 100644 --- a/drivers/infiniband/hw/mlx5/gsi.c +++ b/drivers/infiniband/hw/mlx5/gsi.c @@ -69,15 +69,6 @@ static bool mlx5_ib_deth_sqpn_cap(struct mlx5_ib_dev *dev) return MLX5_CAP_GEN(dev->mdev, set_deth_sqpn); } -static u32 next_outstanding(struct mlx5_ib_gsi_qp *gsi, u32 index) -{ - return ++index % gsi->cap.max_send_wr; -} - -#define for_each_outstanding_wr(gsi, index) \ - for (index = gsi->outstanding_ci; index != gsi->outstanding_pi; \ - index = next_outstanding(gsi, index)) - /* Call with gsi->lock locked */ static void generate_completions(struct mlx5_ib_gsi_qp *gsi) { @@ -85,8 +76,9 @@ static void generate_completions(struct mlx5_ib_gsi_qp *gsi) struct mlx5_ib_gsi_wr *wr; u32 index; - for_each_outstanding_wr(gsi, index) { - wr = &gsi->outstanding_wrs[index]; + for (index = gsi->outstanding_ci; index != gsi->outstanding_pi; + index++) { + wr = &gsi->outstanding_wrs[index % gsi->cap.max_send_wr]; if (!wr->completed) break; @@ -430,8 +422,9 @@ static int mlx5_ib_add_outstanding_wr(struct mlx5_ib_gsi_qp *gsi, return -ENOMEM; } - gsi_wr = &gsi->outstanding_wrs[gsi->outstanding_pi]; - gsi->outstanding_pi = next_outstanding(gsi, gsi->outstanding_pi); + gsi_wr = &gsi->outstanding_wrs[gsi->outstanding_pi % + gsi->cap.max_send_wr]; + gsi->outstanding_pi++; if (!wc) { memset(&gsi_wr->wc, 0, sizeof(gsi_wr->wc)); -- 2.20.1