The branch main has been updated by jhb:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=259a763e343d36a6030e0bba5ae7ed05c123c2fe

commit 259a763e343d36a6030e0bba5ae7ed05c123c2fe
Author:     John Baldwin <[email protected]>
AuthorDate: 2025-12-05 20:56:35 +0000
Commit:     John Baldwin <[email protected]>
CommitDate: 2026-06-22 18:36:52 +0000

    OFED: Implement ib_process_cq_direct
    
    This is largely pulled from the original Linux commit to add cq.c.
    Note that irq_poll is still not supported, but polling should now be
    possible whereas it wasn't really before.
    
    Tested by:      Wafa Hamzah <[email protected]> (mlx5_ib)
    Tested by:      John Baldwin <[email protected]> (iw_cxgbe)
    Obtained from:  Linux commit 14d3a3b2498edadec344cb11e60e66091f5daf63
    Sponsored by:   Chelsio Communications
---
 sys/ofed/drivers/infiniband/core/ib_cq.c | 96 ++++++++++++++++++++++----------
 sys/ofed/include/rdma/ib_verbs.h         |  3 +
 2 files changed, 70 insertions(+), 29 deletions(-)

diff --git a/sys/ofed/drivers/infiniband/core/ib_cq.c 
b/sys/ofed/drivers/infiniband/core/ib_cq.c
index d455f2c7c9ed..d6c897392022 100644
--- a/sys/ofed/drivers/infiniband/core/ib_cq.c
+++ b/sys/ofed/drivers/infiniband/core/ib_cq.c
@@ -39,42 +39,73 @@
 
 #include <rdma/ib_verbs.h>
 
-#define        IB_CQ_POLL_MAX  16
-/* maximum number of completions per poll loop */
-#define        IB_CQ_POLL_BUDGET 65536
-#define        IB_CQ_POLL_FLAGS (IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
+/* # of WCs to poll for with a single call to ib_poll_cq */
+#define IB_POLL_BATCH                  16
 
-static void
-ib_cq_poll_work(struct work_struct *work)
+/* # of WCs to iterate over before yielding */
+#define IB_POLL_BUDGET_WORKQUEUE       65536
+
+#define IB_POLL_FLAGS \
+       (IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
+
+static int __ib_process_cq(struct ib_cq *cq, int budget)
 {
-       struct ib_wc ib_wc[IB_CQ_POLL_MAX];
-       struct ib_cq *cq = container_of(work, struct ib_cq, work);
-       int total = 0;
-       int i;
-       int n;
+       int i, n, completed = 0;
 
-       while (1) {
-               n = ib_poll_cq(cq, IB_CQ_POLL_MAX, ib_wc);
+       while ((n = ib_poll_cq(cq, IB_POLL_BATCH, cq->wc)) > 0) {
                for (i = 0; i < n; i++) {
-                       struct ib_wc *wc = ib_wc + i;
+                       struct ib_wc *wc = &cq->wc[i];
 
-                       if (wc->wr_cqe != NULL)
+                       if (wc->wr_cqe)
                                wc->wr_cqe->done(cq, wc);
-               }
-
-               if (n != IB_CQ_POLL_MAX) {
-                       if (ib_req_notify_cq(cq, IB_CQ_POLL_FLAGS) > 0)
-                               break;
                        else
-                               return;
+                               WARN_ON_ONCE(wc->status == IB_WC_SUCCESS);
                }
-               total += n;
-               if (total >= IB_CQ_POLL_BUDGET)
+
+               completed += n;
+
+               if (n != IB_POLL_BATCH ||
+                   (budget != -1 && completed >= budget))
                        break;
        }
 
-       /* give other work structs a chance */
-       queue_work(ib_comp_wq, &cq->work);
+       return completed;
+}
+
+/**
+ * ib_process_direct_cq - process a CQ in caller context
+ * @cq:                CQ to process
+ * @budget:    number of CQEs to poll for
+ *
+ * This function is used to process all outstanding CQ entries on a
+ * %IB_POLL_DIRECT CQ.  It does not offload CQ processing to a different
+ * context and does not ask for completion interrupts from the HCA.
+ *
+ * Note: for compatibility reasons -1 can be passed in %budget for unlimited
+ * polling.  Do not use this feature in new code, it will be removed soon.
+ */
+int ib_process_cq_direct(struct ib_cq *cq, int budget)
+{
+       WARN_ON_ONCE(cq->poll_ctx != IB_POLL_DIRECT);
+
+       return __ib_process_cq(cq, budget);
+}
+EXPORT_SYMBOL(ib_process_cq_direct);
+
+static void ib_cq_completion_direct(struct ib_cq *cq, void *private)
+{
+       WARN_ONCE(1, "got unsolicited completion for CQ 0x%p\n", cq);
+}
+
+static void ib_cq_poll_work(struct work_struct *work)
+{
+       struct ib_cq *cq = container_of(work, struct ib_cq, work);
+       int completed;
+
+       completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE);
+       if (completed >= IB_POLL_BUDGET_WORKQUEUE ||
+           ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
+               queue_work(ib_comp_wq, &cq->work);
 }
 
 static void
@@ -94,7 +125,7 @@ __ib_alloc_cq_user(struct ib_device *dev, void *private,
                .comp_vector = comp_vector,
        };
        struct ib_cq *cq;
-       int ret;
+       int ret = -ENOMEM;
 
        /*
         * Check for invalid parameters early on to avoid
@@ -118,13 +149,17 @@ __ib_alloc_cq_user(struct ib_device *dev, void *private,
        cq->poll_ctx = poll_ctx;
        atomic_set(&cq->usecnt, 0);
 
+       cq->wc = kmalloc_array(IB_POLL_BATCH, sizeof(*cq->wc), GFP_KERNEL);
+       if (!cq->wc)
+               goto out_free_cq;
+
        ret = dev->create_cq(cq, &cq_attr, NULL);
        if (ret)
-               goto out_free_cq;
+               goto out_free_wc;
 
-       switch (poll_ctx) {
+       switch (cq->poll_ctx) {
        case IB_POLL_DIRECT:
-               cq->comp_handler = NULL;        /* no hardware completions */
+               cq->comp_handler = ib_cq_completion_direct;
                break;
        case IB_POLL_SOFTIRQ:
        case IB_POLL_WORKQUEUE:
@@ -137,6 +172,8 @@ __ib_alloc_cq_user(struct ib_device *dev, void *private,
        }
        return (cq);
 
+out_free_wc:
+       kfree(cq->wc);
 out_free_cq:
        kfree(cq);
        return (ERR_PTR(ret));
@@ -161,6 +198,7 @@ ib_free_cq_user(struct ib_cq *cq, struct ib_udata *udata)
                break;
        }
 
+       kfree(cq->wc);
        cq->device->destroy_cq(cq, udata);
        kfree(cq);
 }
diff --git a/sys/ofed/include/rdma/ib_verbs.h b/sys/ofed/include/rdma/ib_verbs.h
index 086251183a55..8929cf2fe0b1 100644
--- a/sys/ofed/include/rdma/ib_verbs.h
+++ b/sys/ofed/include/rdma/ib_verbs.h
@@ -1472,6 +1472,7 @@ struct ib_cq {
        void                   *cq_context;
        int                     cqe;
        atomic_t                usecnt; /* count number of work queues */
+       struct ib_wc            *wc;
        enum ib_poll_context    poll_ctx;
        struct work_struct      work;
 };
@@ -3354,6 +3355,8 @@ static inline void ib_free_cq(struct ib_cq *cq)
        ib_free_cq_user(cq, NULL);
 }
 
+int ib_process_cq_direct(struct ib_cq *cq, int budget);
+
 /**
  * ib_create_cq - Creates a CQ on the specified device.
  * @device: The device on which to create the CQ.

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