Cleanup rxe_mcast.c code. Minor changes and complete comments. Signed-off-by: Bob Pearson <rpearsonhpe@xxxxxxxxx> --- drivers/infiniband/sw/rxe/rxe_mcast.c | 163 +++++++++++++++++++------- drivers/infiniband/sw/rxe/rxe_verbs.h | 1 + 2 files changed, 124 insertions(+), 40 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_mcast.c b/drivers/infiniband/sw/rxe/rxe_mcast.c index 2fccf69f9a4b..2e5b41063f83 100644 --- a/drivers/infiniband/sw/rxe/rxe_mcast.c +++ b/drivers/infiniband/sw/rxe/rxe_mcast.c @@ -175,6 +175,7 @@ static int __rxe_init_mcg(struct rxe_dev *rxe, union ib_gid *mgid, mcg->rxe = rxe; mcg->index = rxe->mcg_next++; + /* take reference to protect pointer in red-black tree */ kref_get(&mcg->ref_cnt); __rxe_insert_mcg(mcg); @@ -263,6 +264,7 @@ void __rxe_destroy_mcg(struct rxe_mcg *mcg) struct rxe_dev *rxe = mcg->rxe; __rxe_remove_mcg(mcg); + /* drop reference that protected pointer in red-black tree */ kref_put(&mcg->ref_cnt, rxe_cleanup_mcg); rxe_mcast_delete(rxe, &mcg->mgid); @@ -282,11 +284,59 @@ static void rxe_destroy_mcg(struct rxe_mcg *mcg) spin_unlock_bh(&mcg->rxe->mcg_lock); } -static int rxe_mcast_add_grp_elem(struct rxe_dev *rxe, struct rxe_qp *qp, - struct rxe_mcg *mcg) +/** + * __rxe_init_mca - initialize a new mca holding lock + * @qp: qp object + * @mcg: mcg object + * @mca: empty space for new mca + * + * Context: caller must hold references on qp and mcg, rxe->mcg_lock + * and pass memory for new mca + * + * Returns: 0 on success else an error + */ +static int __rxe_init_mca(struct rxe_qp *qp, struct rxe_mcg *mcg, + struct rxe_mca *mca) +{ + struct rxe_dev *rxe = to_rdev(qp->ibqp.device); + int n; + + n = atomic_inc_return(&rxe->mcg_attach); + if (n > rxe->attr.max_total_mcast_qp_attach) { + atomic_dec(&rxe->mcg_attach); + return -ENOMEM; + } + + n = atomic_inc_return(&mcg->qp_num); + if (n > rxe->attr.max_mcast_qp_attach) { + atomic_dec(&mcg->qp_num); + atomic_dec(&rxe->mcg_attach); + return -ENOMEM; + } + + atomic_inc(&qp->mcg_num); + + rxe_add_ref(qp); + mca->qp = qp; + + list_add_tail(&mca->qp_list, &mcg->qp_list); + + return 0; +} + +/** + * rxe_attach_mcg - attach qp to mcg if not already attached + * @mcg: mcg object + * @qp: qp object + * + * Context: caller must hold reference on qp and mcg. + * Returns: 0 on success else an error + */ +static int rxe_attach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp) { + struct rxe_dev *rxe = mcg->rxe; + struct rxe_mca *mca, *tmp; int err; - struct rxe_mca *mca, *new_mca; /* check to see if the qp is already a member of the group */ spin_lock_bh(&rxe->mcg_lock); @@ -298,71 +348,84 @@ static int rxe_mcast_add_grp_elem(struct rxe_dev *rxe, struct rxe_qp *qp, } spin_unlock_bh(&rxe->mcg_lock); - /* speculative alloc new mca without using GFP_ATOMIC */ - new_mca = kzalloc(sizeof(*mca), GFP_KERNEL); - if (!new_mca) + /* speculative alloc new mca */ + mca = kzalloc(sizeof(*mca), GFP_KERNEL); + if (!mca) return -ENOMEM; spin_lock_bh(&rxe->mcg_lock); /* re-check to see if someone else just attached qp */ - list_for_each_entry(mca, &mcg->qp_list, qp_list) { + list_for_each_entry(tmp, &mcg->qp_list, qp_list) { if (mca->qp == qp) { - kfree(new_mca); + kfree(mca); err = 0; - goto out; + goto done; } } - mca = new_mca; - if (atomic_read(&mcg->qp_num) >= rxe->attr.max_mcast_qp_attach) { - err = -ENOMEM; - goto out; - } + err = __rxe_init_mca(qp, mcg, mca); + if (err) + kfree(mca); +done: + spin_unlock_bh(&rxe->mcg_lock); - atomic_inc(&mcg->qp_num); - mca->qp = qp; - atomic_inc(&qp->mcg_num); + return err; +} - list_add_tail(&mca->qp_list, &mcg->qp_list); +/** + * __rxe_cleanup_mca - cleanup mca object holding lock + * @mca: mca object + * @mcg: mcg object + * + * Context: caller must hold a reference to mcg and rxe->mcg_lock + */ +static void __rxe_cleanup_mca(struct rxe_mca *mca, struct rxe_mcg *mcg) +{ + list_del(&mca->qp_list); - err = 0; -out: - spin_unlock_bh(&rxe->mcg_lock); - return err; + rxe_drop_ref(mca->qp); + + atomic_dec(&mcg->qp_num); + atomic_dec(&mcg->rxe->mcg_attach); + atomic_dec(&mca->qp->mcg_num); } -static int rxe_mcast_drop_grp_elem(struct rxe_dev *rxe, struct rxe_qp *qp, - union ib_gid *mgid) +/** + * rxe_detach_mcg - detach qp from mcg + * @mcg: mcg object + * @qp: qp object + * + * Returns: 0 on success else an error if qp is not attached. + */ +static int rxe_detach_mcg(struct rxe_mcg *mcg, struct rxe_qp *qp) { - struct rxe_mcg *mcg; + struct rxe_dev *rxe = mcg->rxe; struct rxe_mca *mca, *tmp; - mcg = rxe_lookup_mcg(rxe, mgid); - if (!mcg) - goto err1; - spin_lock_bh(&rxe->mcg_lock); - list_for_each_entry_safe(mca, tmp, &mcg->qp_list, qp_list) { if (mca->qp == qp) { - list_del(&mca->qp_list); - if (atomic_dec_return(&mcg->qp_num) <= 0) + __rxe_cleanup_mca(mca, mcg); + if (atomic_read(&mcg->qp_num) <= 0) __rxe_destroy_mcg(mcg); - atomic_dec(&qp->mcg_num); - spin_unlock_bh(&rxe->mcg_lock); - kref_put(&mcg->ref_cnt, rxe_cleanup_mcg); kfree(mca); return 0; } } - spin_unlock_bh(&rxe->mcg_lock); - kref_put(&mcg->ref_cnt, rxe_cleanup_mcg); -err1: + return -EINVAL; } +/** + * rxe_attach_mcast - attach qp to multicast group (see IBA-11.3.1) + * @ibqp: (IB) qp object + * @mgid: multicast IP address + * @mlid: multicast LID, ignored for RoCEv2 (see IBA-A17.5.6) + * + * Returns: 0 on success else an errno + */ int rxe_attach_mcast(struct ib_qp *ibqp, union ib_gid *mgid, u16 mlid) { int err; @@ -374,8 +437,11 @@ int rxe_attach_mcast(struct ib_qp *ibqp, union ib_gid *mgid, u16 mlid) if (err) return err; - err = rxe_mcast_add_grp_elem(rxe, qp, mcg); + err = rxe_attach_mcg(mcg, qp); + /* this can happen if we failed to attach a first qp to mcg + * go ahead and destroy mcg + */ if (atomic_read(&mcg->qp_num) == 0) rxe_destroy_mcg(mcg); @@ -383,12 +449,29 @@ int rxe_attach_mcast(struct ib_qp *ibqp, union ib_gid *mgid, u16 mlid) return err; } +/** + * rxe_detach_mcast - detach qp from multicast group (see IBA-11.3.2) + * @ibqp: address of (IB) qp object + * @mgid: multicast IP address + * @mlid: multicast LID, ignored for RoCEv2 (see IBA-A17.5.6) + * + * Returns: 0 on success else an errno + */ int rxe_detach_mcast(struct ib_qp *ibqp, union ib_gid *mgid, u16 mlid) { struct rxe_dev *rxe = to_rdev(ibqp->device); struct rxe_qp *qp = to_rqp(ibqp); + struct rxe_mcg *mcg; + int err; - return rxe_mcast_drop_grp_elem(rxe, qp, mgid); + mcg = rxe_lookup_mcg(rxe, mgid); + if (!mcg) + return -EINVAL; + + err = rxe_detach_mcg(mcg, qp); + kref_put(&mcg->ref_cnt, rxe_cleanup_mcg); + + return err; } /** diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h index 72a913a8e0cb..716f11ec80fe 100644 --- a/drivers/infiniband/sw/rxe/rxe_verbs.h +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h @@ -401,6 +401,7 @@ struct rxe_dev { spinlock_t mcg_lock; /* guard multicast groups */ struct rb_root mcg_tree; atomic_t mcg_num; + atomic_t mcg_attach; unsigned int mcg_next; spinlock_t pending_lock; /* guard pending_mmaps */ -- 2.32.0