RDMA/bnxt_re: Refurbish CQ to NQ hash calculation

There are few use cases where CQ create and destroy
is seen before re-creating the CQ, this kind of use
case is disturbing the RR distribution and all the
active CQ getting mapped to only 2 NQ alternatively.

Fixing the CQ to NQ hash calculation by implementing
a quick load sorting mechanism under a mutex.

Using this, if the CQ was allocated and destroyed
before using it, the nq selecting algorithm still
obtains the least loaded CQ. Thus balancing the load
on NQs.

Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/1731577748-1804-4-git-send-email-selvin.xavier@broadcom.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

diff --git a/drivers/infiniband/hw/bnxt_re/bnxt_re.h b/drivers/infiniband/hw/bnxt_re/bnxt_re.h
index d1c839efab0579ac92d2276ad89995ebf98d3164..5f64fc496812ea27cce19625d441b603901e7d4a 100644 (file)
--- a/drivers/infiniband/hw/bnxt_re/bnxt_re.h
+++ b/drivers/infiniband/hw/bnxt_re/bnxt_re.h
@@ -159,6 +159,8 @@ struct bnxt_re_pacing {
 struct bnxt_re_nq_record {
        struct bnxt_qplib_nq    nq[BNXT_RE_MAX_MSIX];
        int                     num_msix;
+       /* serialize NQ access */
+       struct mutex            load_lock;
 };
 
 #define MAX_CQ_HASH_BITS               (16)

diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.c b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
index a9c32c031705b14a58051712773cb811276b7e0e..f6e9eefc95d6d8f2e55fbcc26e62284b8876443c 100644 (file)
--- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
+++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
@@ -3029,6 +3029,28 @@ int bnxt_re_post_recv(struct ib_qp *ib_qp, const struct ib_recv_wr *wr,
        return rc;
 }
 
+static struct bnxt_qplib_nq *bnxt_re_get_nq(struct bnxt_re_dev *rdev)
+{
+       int min, indx;
+
+       mutex_lock(&rdev->nqr->load_lock);
+       for (indx = 0, min = 0; indx < (rdev->nqr->num_msix - 1); indx++) {
+               if (rdev->nqr->nq[min].load > rdev->nqr->nq[indx].load)
+                       min = indx;
+       }
+       rdev->nqr->nq[min].load++;
+       mutex_unlock(&rdev->nqr->load_lock);
+
+       return &rdev->nqr->nq[min];
+}
+
+static void bnxt_re_put_nq(struct bnxt_re_dev *rdev, struct bnxt_qplib_nq *nq)
+{
+       mutex_lock(&rdev->nqr->load_lock);
+       nq->load--;
+       mutex_unlock(&rdev->nqr->load_lock);
+}
+
 /* Completion Queues */
 int bnxt_re_destroy_cq(struct ib_cq *ib_cq, struct ib_udata *udata)
 {
@@ -3047,6 +3069,8 @@ int bnxt_re_destroy_cq(struct ib_cq *ib_cq, struct ib_udata *udata)
                hash_del(&cq->hash_entry);
        }
        bnxt_qplib_destroy_cq(&rdev->qplib_res, &cq->qplib_cq);
+
+       bnxt_re_put_nq(rdev, nq);
        ib_umem_release(cq->umem);
 
        atomic_dec(&rdev->stats.res.cq_count);
@@ -3065,8 +3089,6 @@ int bnxt_re_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
                rdma_udata_to_drv_context(udata, struct bnxt_re_ucontext, ib_uctx);
        struct bnxt_qplib_dev_attr *dev_attr = &rdev->dev_attr;
        struct bnxt_qplib_chip_ctx *cctx;
-       struct bnxt_qplib_nq *nq = NULL;
-       unsigned int nq_alloc_cnt;
        int cqe = attr->cqe;
        int rc, entries;
        u32 active_cqs;
@@ -3117,16 +3139,10 @@ int bnxt_re_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
 
                cq->qplib_cq.dpi = &rdev->dpi_privileged;
        }
-       /*
-        * Allocating the NQ in a round robin fashion. nq_alloc_cnt is a
-        * used for getting the NQ index.
-        */
-       nq_alloc_cnt = atomic_inc_return(&rdev->nq_alloc_cnt);
-       nq = &rdev->nqr->nq[nq_alloc_cnt % (rdev->nqr->num_msix - 1)];
        cq->qplib_cq.max_wqe = entries;
-       cq->qplib_cq.cnq_hw_ring_id = nq->ring_id;
-       cq->qplib_cq.nq = nq;
        cq->qplib_cq.coalescing = &rdev->cq_coalescing;
+       cq->qplib_cq.nq = bnxt_re_get_nq(rdev);
+       cq->qplib_cq.cnq_hw_ring_id = cq->qplib_cq.nq->ring_id;
 
        rc = bnxt_qplib_create_cq(&rdev->qplib_res, &cq->qplib_cq);
        if (rc) {
@@ -3136,7 +3152,6 @@ int bnxt_re_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
 
        cq->ib_cq.cqe = entries;
        cq->cq_period = cq->qplib_cq.period;
-       nq->budget++;
 
        active_cqs = atomic_inc_return(&rdev->stats.res.cq_count);
        if (active_cqs > rdev->stats.res.cq_watermark)

diff --git a/drivers/infiniband/hw/bnxt_re/main.c b/drivers/infiniband/hw/bnxt_re/main.c
index 9669defcebf65ea9308c708ebd2d8886d7af5ede..fcaf2b3cc01db36df9a0139ab1b86fe71f0ff797 100644 (file)
--- a/drivers/infiniband/hw/bnxt_re/main.c
+++ b/drivers/infiniband/hw/bnxt_re/main.c
@@ -1566,6 +1566,8 @@ static int bnxt_re_init_res(struct bnxt_re_dev *rdev)
 
        bnxt_qplib_init_res(&rdev->qplib_res);
 
+       mutex_init(&rdev->nqr->load_lock);
+
        for (i = 1; i < rdev->nqr->num_msix ; i++) {
                db_offt = rdev->en_dev->msix_entries[i].db_offset;
                rc = bnxt_qplib_enable_nq(rdev->en_dev->pdev, &rdev->nqr->nq[i - 1],

diff --git a/drivers/infiniband/hw/bnxt_re/qplib_fp.c b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
index e2eea714e9776bccfb55e56d4e7dfb7526a57609..e56f42fddefea4e54fae8de56042d31291f969e1 100644 (file)
--- a/drivers/infiniband/hw/bnxt_re/qplib_fp.c
+++ b/drivers/infiniband/hw/bnxt_re/qplib_fp.c
@@ -551,6 +551,7 @@ int bnxt_qplib_enable_nq(struct pci_dev *pdev, struct bnxt_qplib_nq *nq,
        nq->pdev = pdev;
        nq->cqn_handler = cqn_handler;
        nq->srqn_handler = srqn_handler;
+       nq->load = 0;
 
        /* Have a task to schedule CQ notifiers in post send case */
        nq->cqn_wq  = create_singlethread_workqueue("bnxt_qplib_nq");

diff --git a/drivers/infiniband/hw/bnxt_re/qplib_fp.h b/drivers/infiniband/hw/bnxt_re/qplib_fp.h
index b5a905819ecce1a7effa109c8fea5eef137978d4..8ff56d7320cac576f869742bda43b9d7fdd99855 100644 (file)
--- a/drivers/infiniband/hw/bnxt_re/qplib_fp.h
+++ b/drivers/infiniband/hw/bnxt_re/qplib_fp.h
@@ -519,6 +519,7 @@ struct bnxt_qplib_nq {
        struct tasklet_struct           nq_tasklet;
        bool                            requested;
        int                             budget;
+       u32                             load;
 
        cqn_handler_t                   cqn_handler;
        srqn_handler_t                  srqn_handler;