IB/hns: Fix the bug when free cq

If the resources of cq are freed while executing the user case, hardware
can not been notified in hip06 SoC. Then hardware will hold on when it
writes the cq buffer which has been released.

In order to slove this problem, RoCE driver checks the CQE counter, and
ensure that the outstanding CQE have been written. Then the cq buffer
can be released.

Signed-off-by: Shaobo Xu <xushaobo2@huawei.com>
Reviewed-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
index f67a3bf..b8111b0 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v1.c
@@ -3763,6 +3763,58 @@ int hns_roce_v1_destroy_qp(struct ib_qp *ibqp)
 	return 0;
 }
 
+int hns_roce_v1_destroy_cq(struct ib_cq *ibcq)
+{
+	struct hns_roce_dev *hr_dev = to_hr_dev(ibcq->device);
+	struct hns_roce_cq *hr_cq = to_hr_cq(ibcq);
+	struct device *dev = &hr_dev->pdev->dev;
+	u32 cqe_cnt_ori;
+	u32 cqe_cnt_cur;
+	u32 cq_buf_size;
+	int wait_time = 0;
+	int ret = 0;
+
+	hns_roce_free_cq(hr_dev, hr_cq);
+
+	/*
+	 * Before freeing cq buffer, we need to ensure that the outstanding CQE
+	 * have been written by checking the CQE counter.
+	 */
+	cqe_cnt_ori = roce_read(hr_dev, ROCEE_SCAEP_WR_CQE_CNT);
+	while (1) {
+		if (roce_read(hr_dev, ROCEE_CAEP_CQE_WCMD_EMPTY) &
+		    HNS_ROCE_CQE_WCMD_EMPTY_BIT)
+			break;
+
+		cqe_cnt_cur = roce_read(hr_dev, ROCEE_SCAEP_WR_CQE_CNT);
+		if ((cqe_cnt_cur - cqe_cnt_ori) >= HNS_ROCE_MIN_CQE_CNT)
+			break;
+
+		msleep(HNS_ROCE_EACH_FREE_CQ_WAIT_MSECS);
+		if (wait_time > HNS_ROCE_MAX_FREE_CQ_WAIT_CNT) {
+			dev_warn(dev, "Destroy cq 0x%lx timeout!\n",
+				hr_cq->cqn);
+			ret = -ETIMEDOUT;
+			break;
+		}
+		wait_time++;
+	}
+
+	hns_roce_mtt_cleanup(hr_dev, &hr_cq->hr_buf.hr_mtt);
+
+	if (ibcq->uobject)
+		ib_umem_release(hr_cq->umem);
+	else {
+		/* Free the buff of stored cq */
+		cq_buf_size = (ibcq->cqe + 1) * hr_dev->caps.cq_entry_sz;
+		hns_roce_buf_free(hr_dev, cq_buf_size, &hr_cq->hr_buf.hr_buf);
+	}
+
+	kfree(hr_cq);
+
+	return ret;
+}
+
 struct hns_roce_v1_priv hr_v1_priv;
 
 struct hns_roce_hw hns_roce_hw_v1 = {
@@ -3784,5 +3836,6 @@ struct hns_roce_hw hns_roce_hw_v1 = {
 	.req_notify_cq = hns_roce_v1_req_notify_cq,
 	.poll_cq = hns_roce_v1_poll_cq,
 	.dereg_mr = hns_roce_v1_dereg_mr,
+	.destroy_cq = hns_roce_v1_destroy_cq,
 	.priv = &hr_v1_priv,
 };