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
