From: Yuval Basson ybason@marvell.com
[ Upstream commit acca72e2b031b9fbb4184511072bd246a0abcebc ]
QP's with the same SRQ, working on different CQs and running in parallel on different CPUs could lead to a race when maintaining the SRQ consumer count, and leads to FW running out of SRQs. Update the consumer atomically. Make sure the wqe_prod is updated after the sge_prod due to FW requirements.
Fixes: 3491c9e799fb ("qedr: Add support for kernel mode SRQ's") Link: https://lore.kernel.org/r/20200708195526.31040-1-ybason@marvell.com Signed-off-by: Michal Kalderon mkalderon@marvell.com Signed-off-by: Yuval Basson ybason@marvell.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/hw/qedr/qedr.h | 4 ++-- drivers/infiniband/hw/qedr/verbs.c | 22 ++++++++++------------ 2 files changed, 12 insertions(+), 14 deletions(-)
diff --git a/drivers/infiniband/hw/qedr/qedr.h b/drivers/infiniband/hw/qedr/qedr.h index 8e927f6c15203..ed56df319d2df 100644 --- a/drivers/infiniband/hw/qedr/qedr.h +++ b/drivers/infiniband/hw/qedr/qedr.h @@ -349,10 +349,10 @@ struct qedr_srq_hwq_info { u32 wqe_prod; u32 sge_prod; u32 wr_prod_cnt; - u32 wr_cons_cnt; + atomic_t wr_cons_cnt; u32 num_elems;
- u32 *virt_prod_pair_addr; + struct rdma_srq_producers *virt_prod_pair_addr; dma_addr_t phy_prod_pair_addr; };
diff --git a/drivers/infiniband/hw/qedr/verbs.c b/drivers/infiniband/hw/qedr/verbs.c index 8b4240c1cc763..16a994fd7d0a7 100644 --- a/drivers/infiniband/hw/qedr/verbs.c +++ b/drivers/infiniband/hw/qedr/verbs.c @@ -3460,7 +3460,7 @@ static u32 qedr_srq_elem_left(struct qedr_srq_hwq_info *hw_srq) * count and consumer count and subtract it from max * work request supported so that we get elements left. */ - used = hw_srq->wr_prod_cnt - hw_srq->wr_cons_cnt; + used = hw_srq->wr_prod_cnt - (u32)atomic_read(&hw_srq->wr_cons_cnt);
return hw_srq->max_wr - used; } @@ -3475,7 +3475,6 @@ int qedr_post_srq_recv(struct ib_srq *ibsrq, const struct ib_recv_wr *wr, unsigned long flags; int status = 0; u32 num_sge; - u32 offset;
spin_lock_irqsave(&srq->lock, flags);
@@ -3488,7 +3487,8 @@ int qedr_post_srq_recv(struct ib_srq *ibsrq, const struct ib_recv_wr *wr, if (!qedr_srq_elem_left(hw_srq) || wr->num_sge > srq->hw_srq.max_sges) { DP_ERR(dev, "Can't post WR (%d,%d) || (%d > %d)\n", - hw_srq->wr_prod_cnt, hw_srq->wr_cons_cnt, + hw_srq->wr_prod_cnt, + atomic_read(&hw_srq->wr_cons_cnt), wr->num_sge, srq->hw_srq.max_sges); status = -ENOMEM; *bad_wr = wr; @@ -3522,22 +3522,20 @@ int qedr_post_srq_recv(struct ib_srq *ibsrq, const struct ib_recv_wr *wr, hw_srq->sge_prod++; }
- /* Flush WQE and SGE information before + /* Update WQE and SGE information before * updating producer. */ - wmb(); + dma_wmb();
/* SRQ producer is 8 bytes. Need to update SGE producer index * in first 4 bytes and need to update WQE producer in * next 4 bytes. */ - *srq->hw_srq.virt_prod_pair_addr = hw_srq->sge_prod; - offset = offsetof(struct rdma_srq_producers, wqe_prod); - *((u8 *)srq->hw_srq.virt_prod_pair_addr + offset) = - hw_srq->wqe_prod; + srq->hw_srq.virt_prod_pair_addr->sge_prod = hw_srq->sge_prod; + /* Make sure sge producer is updated first */ + dma_wmb(); + srq->hw_srq.virt_prod_pair_addr->wqe_prod = hw_srq->wqe_prod;
- /* Flush producer after updating it. */ - wmb(); wr = wr->next; }
@@ -3956,7 +3954,7 @@ static int process_resp_one_srq(struct qedr_dev *dev, struct qedr_qp *qp, } else { __process_resp_one(dev, qp, cq, wc, resp, wr_id); } - srq->hw_srq.wr_cons_cnt++; + atomic_inc(&srq->hw_srq.wr_cons_cnt);
return 1; }