On 2019/11/16 5:06, Jason Gunthorpe wrote: > On Tue, Nov 12, 2019 at 08:52:03PM +0800, Yixian Liu wrote: >> HiP08 RoCE hardware lacks ability(a known hardware problem) to flush >> outstanding WQEs if QP state gets into errored mode for some reason. >> To overcome this hardware problem and as a workaround, when QP is >> detected to be in errored state during various legs like post send, >> post receive etc [1], flush needs to be performed from the driver. >> >> The earlier patch[1] sent to solve the hardware limitation explained >> in the cover-letter had a bug in the software flushing leg. It >> acquired mutex while modifying QP state to errored state and while >> conveying it to the hardware using the mailbox. This caused leg to >> sleep while holding spin-lock and caused crash. >> >> Suggested Solution: >> we have proposed to defer the flushing of the QP in the Errored state >> using the workqueue to get around with the limitation of our hardware. >> >> This patch adds the framework of the workqueue and the flush handler >> function. >> >> [1] https://patchwork.kernel.org/patch/10534271/ >> >> Signed-off-by: Yixian Liu <liuyixian@xxxxxxxxxx> >> Reviewed-by: Salil Mehta <salil.mehta@xxxxxxxxxx> >> drivers/infiniband/hw/hns/hns_roce_device.h | 3 +++ >> drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 4 ++-- >> drivers/infiniband/hw/hns/hns_roce_qp.c | 33 +++++++++++++++++++++++++++++ >> 3 files changed, 38 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h >> index a1b712e..42d8a5a 100644 >> +++ b/drivers/infiniband/hw/hns/hns_roce_device.h >> @@ -906,6 +906,7 @@ struct hns_roce_caps { >> struct hns_roce_work { >> struct hns_roce_dev *hr_dev; >> struct work_struct work; >> + struct hns_roce_qp *hr_qp; >> u32 qpn; >> u32 cqn; >> int event_type; >> @@ -1034,6 +1035,7 @@ struct hns_roce_dev { >> const struct hns_roce_hw *hw; >> void *priv; >> struct workqueue_struct *irq_workq; >> + struct hns_roce_work flush_work; >> const struct hns_roce_dfx_hw *dfx; >> }; >> >> @@ -1226,6 +1228,7 @@ struct ib_qp *hns_roce_create_qp(struct ib_pd *ib_pd, >> struct ib_udata *udata); >> int hns_roce_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, >> int attr_mask, struct ib_udata *udata); >> +void init_flush_work(struct hns_roce_dev *hr_dev, struct hns_roce_qp *hr_qp); >> void *get_recv_wqe(struct hns_roce_qp *hr_qp, int n); >> void *get_send_wqe(struct hns_roce_qp *hr_qp, int n); >> void *get_send_extend_sge(struct hns_roce_qp *hr_qp, int n); >> diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c >> index 907c951..ec48e7e 100644 >> +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c >> @@ -5967,8 +5967,8 @@ static int hns_roce_v2_init_eq_table(struct hns_roce_dev *hr_dev) >> goto err_request_irq_fail; >> } >> >> - hr_dev->irq_workq = >> - create_singlethread_workqueue("hns_roce_irq_workqueue"); >> + hr_dev->irq_workq = alloc_workqueue("hns_roce_irq_workqueue", >> + WQ_MEM_RECLAIM, 0); >> if (!hr_dev->irq_workq) { >> dev_err(dev, "Create irq workqueue failed!\n"); >> ret = -ENOMEM; >> diff --git a/drivers/infiniband/hw/hns/hns_roce_qp.c b/drivers/infiniband/hw/hns/hns_roce_qp.c >> index 9442f01..0111f2e 100644 >> +++ b/drivers/infiniband/hw/hns/hns_roce_qp.c >> @@ -43,6 +43,39 @@ >> >> #define SQP_NUM (2 * HNS_ROCE_MAX_PORTS) >> >> +static void flush_work_handle(struct work_struct *work) >> +{ >> + struct hns_roce_work *flush_work = container_of(work, >> + struct hns_roce_work, work); >> + struct hns_roce_qp *hr_qp = flush_work->hr_qp; >> + struct device *dev = flush_work->hr_dev->dev; >> + struct ib_qp_attr attr; >> + int attr_mask; >> + int ret; >> + >> + attr_mask = IB_QP_STATE; >> + attr.qp_state = IB_QPS_ERR; >> + >> + ret = hns_roce_modify_qp(&hr_qp->ibqp, &attr, attr_mask, NULL); >> + if (ret) >> + dev_err(dev, "Modify QP to error state failed(%d) during CQE flush\n", >> + ret); >> + >> + if (atomic_dec_and_test(&hr_qp->refcount)) >> + complete(&hr_qp->free); >> +} >> + >> +void init_flush_work(struct hns_roce_dev *hr_dev, struct hns_roce_qp *hr_qp) >> +{ >> + struct hns_roce_work *flush_work = &hr_dev->flush_work; >> + >> + flush_work->hr_dev = hr_dev; >> + flush_work->hr_qp = hr_qp; >> + INIT_WORK(&flush_work->work, flush_work_handle); >> + atomic_inc(&hr_qp->refcount); >> + queue_work(hr_dev->irq_workq, &flush_work->work); > > It kind of looks like this can be called multiple times? It won't work > right unless it is called exactly once > > Jason Yes, you are right. So I think the reasonable solution is to allocate it dynamically, and I think it is a very very little chance that the allocation will be failed. If this happened, I think the application also needs to be over. So I will fall back to v1 for this part in next version. flush_work = kzalloc(sizeof(struct hns_roce_flush_work), GFP_ATOMIC) if (!flush_work) return; Or, could you give me some advice for it? Thanks. > > . >
