Re: [PATCH for-next 4/4] RDMA/efa: CQ notifications
From: Jason Gunthorpe <jgg@nvidia.com>
Date: 2021-08-20 18:27:06
On Wed, Aug 11, 2021 at 06:11:31PM +0300, Gal Pressman wrote:
quoted hunk ↗ jump to hunk
diff --git a/drivers/infiniband/hw/efa/efa_main.c b/drivers/infiniband/hw/efa/efa_main.c index 417dea5f90cf..29db4dec02f0 100644 +++ b/drivers/infiniband/hw/efa/efa_main.c@@ -67,6 +67,46 @@ static void efa_release_bars(struct efa_dev *dev, int bars_mask) pci_release_selected_regions(pdev, release_bars); } +static void efa_process_comp_eqe(struct efa_dev *dev, struct efa_admin_eqe *eqe) +{ + u16 cqn = eqe->u.comp_event.cqn; + struct efa_cq *cq; + + cq = xa_load(&dev->cqs_xa, cqn); + if (unlikely(!cq)) {
This seems unlikely to be correct, what prevents cq from being destroyed concurrently? A comp_handler cannot be running after cq destroy completes.
quoted hunk ↗ jump to hunk
@@ -421,6 +551,7 @@ static struct efa_dev *efa_probe_device(struct pci_dev *pdev) edev->efa_dev = dev; edev->dmadev = &pdev->dev; dev->pdev = pdev; + xa_init_flags(&dev->cqs_xa, XA_FLAGS_LOCK_IRQ);
And this is confusing too, since the above is the only reference and doesn't take the xa_lock why does the xa need to use LOCK_IRQ? Jason