From 8a0a5fe0c462438a8c423ebaa0fbb7af5055a155 Mon Sep 17 00:00:00 2001 From: Bob Pearson Date: Tue, 8 Feb 2022 15:16:39 -0600 Subject: [PATCH] RDMA/rxe: Replace pool key by rxe->mcg_tree Continuing to decouple mcg from rxe pools. Create red-black tree code in rxe_mcast.c to hold mcg index. Replace pool key calls by calls to local red-black routines. Link: https://lore.kernel.org/r/20220208211644.123457-6-rpearsonhpe@gmail.com Signed-off-by: Bob Pearson Signed-off-by: Jason Gunthorpe --- drivers/infiniband/sw/rxe/rxe.c | 2 + drivers/infiniband/sw/rxe/rxe_loc.h | 3 +- drivers/infiniband/sw/rxe/rxe_mcast.c | 262 ++++++++++++++++++++++++++-------- drivers/infiniband/sw/rxe/rxe_recv.c | 4 +- drivers/infiniband/sw/rxe/rxe_verbs.h | 6 +- 5 files changed, 213 insertions(+), 64 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe.c b/drivers/infiniband/sw/rxe/rxe.c index 7386a51..dc36148 100644 --- a/drivers/infiniband/sw/rxe/rxe.c +++ b/drivers/infiniband/sw/rxe/rxe.c @@ -203,7 +203,9 @@ static int rxe_init(struct rxe_dev *rxe) spin_lock_init(&rxe->pending_lock); INIT_LIST_HEAD(&rxe->pending_mmaps); + /* init multicast support */ spin_lock_init(&rxe->mcg_lock); + rxe->mcg_tree = RB_ROOT; mutex_init(&rxe->usdev_lock); diff --git a/drivers/infiniband/sw/rxe/rxe_loc.h b/drivers/infiniband/sw/rxe/rxe_loc.h index af40e3c..d418318 100644 --- a/drivers/infiniband/sw/rxe/rxe_loc.h +++ b/drivers/infiniband/sw/rxe/rxe_loc.h @@ -40,9 +40,10 @@ void rxe_cq_disable(struct rxe_cq *cq); void rxe_cq_cleanup(struct rxe_pool_elem *arg); /* rxe_mcast.c */ -void rxe_mc_cleanup(struct rxe_pool_elem *arg); +struct rxe_mcg *rxe_lookup_mcg(struct rxe_dev *rxe, union ib_gid *mgid); int rxe_attach_mcast(struct ib_qp *ibqp, union ib_gid *mgid, u16 mlid); int rxe_detach_mcast(struct ib_qp *ibqp, union ib_gid *mgid, u16 mlid); +void rxe_mc_cleanup(struct rxe_pool_elem *elem); /* rxe_mmap.c */ struct rxe_mmap_info { diff --git a/drivers/infiniband/sw/rxe/rxe_mcast.c b/drivers/infiniband/sw/rxe/rxe_mcast.c index 1995d24..8585521 100644 --- a/drivers/infiniband/sw/rxe/rxe_mcast.c +++ b/drivers/infiniband/sw/rxe/rxe_mcast.c @@ -25,57 +25,229 @@ static int rxe_mcast_delete(struct rxe_dev *rxe, union ib_gid *mgid) return dev_mc_del(rxe->ndev, ll_addr); } -/* caller should hold rxe->mcg_lock */ -static struct rxe_mcg *__rxe_create_mcg(struct rxe_dev *rxe, - struct rxe_pool *pool, +/** + * __rxe_insert_mcg - insert an mcg into red-black tree (rxe->mcg_tree) + * @mcg: mcg object with an embedded red-black tree node + * + * Context: caller must hold a reference to mcg and rxe->mcg_lock and + * is responsible to avoid adding the same mcg twice to the tree. + */ +static void __rxe_insert_mcg(struct rxe_mcg *mcg) +{ + struct rb_root *tree = &mcg->rxe->mcg_tree; + struct rb_node **link = &tree->rb_node; + struct rb_node *node = NULL; + struct rxe_mcg *tmp; + int cmp; + + while (*link) { + node = *link; + tmp = rb_entry(node, struct rxe_mcg, node); + + cmp = memcmp(&tmp->mgid, &mcg->mgid, sizeof(mcg->mgid)); + if (cmp > 0) + link = &(*link)->rb_left; + else + link = &(*link)->rb_right; + } + + rb_link_node(&mcg->node, node, link); + rb_insert_color(&mcg->node, tree); +} + +/** + * __rxe_remove_mcg - remove an mcg from red-black tree holding lock + * @mcg: mcast group object with an embedded red-black tree node + * + * Context: caller must hold a reference to mcg and rxe->mcg_lock + */ +static void __rxe_remove_mcg(struct rxe_mcg *mcg) +{ + rb_erase(&mcg->node, &mcg->rxe->mcg_tree); +} + +/** + * __rxe_lookup_mcg - lookup mcg in rxe->mcg_tree while holding lock + * @rxe: rxe device object + * @mgid: multicast IP address + * + * Context: caller must hold rxe->mcg_lock + * Returns: mcg on success and takes a ref to mcg else NULL + */ +static struct rxe_mcg *__rxe_lookup_mcg(struct rxe_dev *rxe, union ib_gid *mgid) { + struct rb_root *tree = &rxe->mcg_tree; struct rxe_mcg *mcg; - int err; + struct rb_node *node; + int cmp; - mcg = rxe_alloc_locked(pool); - if (!mcg) - return ERR_PTR(-ENOMEM); + node = tree->rb_node; - err = rxe_mcast_add(rxe, mgid); - if (unlikely(err)) { - rxe_drop_ref(mcg); - return ERR_PTR(err); + while (node) { + mcg = rb_entry(node, struct rxe_mcg, node); + + cmp = memcmp(&mcg->mgid, mgid, sizeof(*mgid)); + + if (cmp > 0) + node = node->rb_left; + else if (cmp < 0) + node = node->rb_right; + else + break; } + if (node) { + rxe_add_ref(mcg); + return mcg; + } + + return NULL; +} + +/** + * rxe_lookup_mcg - lookup up mcg in red-back tree + * @rxe: rxe device object + * @mgid: multicast IP address + * + * Returns: mcg if found else NULL + */ +struct rxe_mcg *rxe_lookup_mcg(struct rxe_dev *rxe, union ib_gid *mgid) +{ + struct rxe_mcg *mcg; + unsigned long flags; + + spin_lock_irqsave(&rxe->mcg_lock, flags); + mcg = __rxe_lookup_mcg(rxe, mgid); + spin_unlock_irqrestore(&rxe->mcg_lock, flags); + + return mcg; +} + +/** + * __rxe_init_mcg - initialize a new mcg + * @rxe: rxe device + * @mgid: multicast address as a gid + * @mcg: new mcg object + * + * Context: caller should hold rxe->mcg lock + * Returns: 0 on success else an error + */ +static int __rxe_init_mcg(struct rxe_dev *rxe, union ib_gid *mgid, + struct rxe_mcg *mcg) +{ + int err; + + err = rxe_mcast_add(rxe, mgid); + if (unlikely(err)) + return err; + + memcpy(&mcg->mgid, mgid, sizeof(mcg->mgid)); INIT_LIST_HEAD(&mcg->qp_list); mcg->rxe = rxe; - /* rxe_alloc_locked takes a ref on mcg but that will be + /* caller holds a ref on mcg but that will be * dropped when mcg goes out of scope. We need to take a ref * on the pointer that will be saved in the red-black tree - * by rxe_add_key and used to lookup mcg from mgid later. - * Adding key makes object visible to outside so this should + * by __rxe_insert_mcg and used to lookup mcg from mgid later. + * Inserting mcg makes it visible to outside so this should * be done last after the object is ready. */ rxe_add_ref(mcg); - rxe_add_key_locked(mcg, mgid); + __rxe_insert_mcg(mcg); - return mcg; + return 0; } -static struct rxe_mcg *rxe_get_mcg(struct rxe_dev *rxe, - union ib_gid *mgid) +/** + * rxe_get_mcg - lookup or allocate a mcg + * @rxe: rxe device object + * @mgid: multicast IP address as a gid + * + * Returns: mcg on success else ERR_PTR(error) + */ +static struct rxe_mcg *rxe_get_mcg(struct rxe_dev *rxe, union ib_gid *mgid) { - struct rxe_mcg *mcg; struct rxe_pool *pool = &rxe->mc_grp_pool; + struct rxe_mcg *mcg, *tmp; unsigned long flags; + int err; - if (rxe->attr.max_mcast_qp_attach == 0) + if (rxe->attr.max_mcast_grp == 0) return ERR_PTR(-EINVAL); - spin_lock_irqsave(&rxe->mcg_lock, flags); - mcg = rxe_pool_get_key_locked(pool, mgid); + /* check to see if mcg already exists */ + mcg = rxe_lookup_mcg(rxe, mgid); + if (mcg) + return mcg; + + /* speculative alloc of new mcg */ + mcg = rxe_alloc(pool); if (!mcg) - mcg = __rxe_create_mcg(rxe, pool, mgid); - spin_unlock_irqrestore(&rxe->mcg_lock, flags); + return ERR_PTR(-ENOMEM); + + spin_lock_irqsave(&rxe->mcg_lock, flags); + /* re-check to see if someone else just added it */ + tmp = __rxe_lookup_mcg(rxe, mgid); + if (tmp) { + rxe_drop_ref(mcg); + mcg = tmp; + goto out; + } + + if (atomic_inc_return(&rxe->mcg_num) > rxe->attr.max_mcast_grp) { + err = -ENOMEM; + goto err_dec; + } + err = __rxe_init_mcg(rxe, mgid, mcg); + if (err) + goto err_dec; +out: + spin_unlock_irqrestore(&rxe->mcg_lock, flags); return mcg; + +err_dec: + atomic_dec(&rxe->mcg_num); + spin_unlock_irqrestore(&rxe->mcg_lock, flags); + rxe_drop_ref(mcg); + return ERR_PTR(err); +} + +/** + * __rxe_destroy_mcg - destroy mcg object holding rxe->mcg_lock + * @mcg: the mcg object + * + * Context: caller is holding rxe->mcg_lock + * no qp's are attached to mcg + */ +static void __rxe_destroy_mcg(struct rxe_mcg *mcg) +{ + /* remove mcg from red-black tree then drop ref */ + __rxe_remove_mcg(mcg); + rxe_drop_ref(mcg); + + rxe_mcast_delete(mcg->rxe, &mcg->mgid); +} + +/** + * rxe_destroy_mcg - destroy mcg object + * @mcg: the mcg object + * + * Context: no qp's are attached to mcg + */ +static void rxe_destroy_mcg(struct rxe_mcg *mcg) +{ + unsigned long flags; + + spin_lock_irqsave(&mcg->rxe->mcg_lock, flags); + __rxe_destroy_mcg(mcg); + spin_unlock_irqrestore(&mcg->rxe->mcg_lock, flags); +} + +void rxe_mc_cleanup(struct rxe_pool_elem *elem) +{ + /* nothing left to do for now */ } static int rxe_attach_mcg(struct rxe_dev *rxe, struct rxe_qp *qp, @@ -131,31 +303,6 @@ out: return err; } -/* caller should be holding rxe->mcg_lock */ -static void __rxe_destroy_mcg(struct rxe_mcg *mcg) -{ - /* first remove mcg from red-black tree then drop ref */ - rxe_drop_key_locked(mcg); - rxe_drop_ref(mcg); - - rxe_mcast_delete(mcg->rxe, &mcg->mgid); -} - -static void rxe_destroy_mcg(struct rxe_mcg *mcg) -{ - struct rxe_dev *rxe = mcg->rxe; - unsigned long flags; - - spin_lock_irqsave(&rxe->mcg_lock, flags); - __rxe_destroy_mcg(mcg); - spin_unlock_irqrestore(&rxe->mcg_lock, flags); -} - -void rxe_mc_cleanup(struct rxe_pool_elem *elem) -{ - /* nothing left to do for now */ -} - static int rxe_detach_mcg(struct rxe_dev *rxe, struct rxe_qp *qp, union ib_gid *mgid) { @@ -164,17 +311,16 @@ static int rxe_detach_mcg(struct rxe_dev *rxe, struct rxe_qp *qp, unsigned long flags; int err; - spin_lock_irqsave(&rxe->mcg_lock, flags); - mcg = rxe_pool_get_key_locked(&rxe->mc_grp_pool, mgid); - if (!mcg) { - /* we didn't find the mcast group for mgid */ - err = -EINVAL; - goto out_unlock; - } + mcg = rxe_lookup_mcg(rxe, mgid); + if (!mcg) + return -EINVAL; + spin_lock_irqsave(&rxe->mcg_lock, flags); list_for_each_entry_safe(mca, tmp, &mcg->qp_list, qp_list) { if (mca->qp == qp) { list_del(&mca->qp_list); + atomic_dec(&qp->mcg_num); + rxe_drop_ref(qp); /* if the number of qp's attached to the * mcast group falls to zero go ahead and @@ -185,10 +331,8 @@ static int rxe_detach_mcg(struct rxe_dev *rxe, struct rxe_qp *qp, if (atomic_dec_return(&mcg->qp_num) <= 0) __rxe_destroy_mcg(mcg); - atomic_dec(&qp->mcg_num); - /* drop the ref from get key. This will free the - * object if num_qp is zero. + * object if qp_num is zero. */ rxe_drop_ref(mcg); kfree(mca); diff --git a/drivers/infiniband/sw/rxe/rxe_recv.c b/drivers/infiniband/sw/rxe/rxe_recv.c index d91c666..fb26590 100644 --- a/drivers/infiniband/sw/rxe/rxe_recv.c +++ b/drivers/infiniband/sw/rxe/rxe_recv.c @@ -246,7 +246,7 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) memcpy(&dgid, &ipv6_hdr(skb)->daddr, sizeof(dgid)); /* lookup mcast group corresponding to mgid, takes a ref */ - mcg = rxe_pool_get_key(&rxe->mc_grp_pool, &dgid); + mcg = rxe_lookup_mcg(rxe, &dgid); if (!mcg) goto drop; /* mcast group not registered */ @@ -300,7 +300,7 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) spin_unlock_bh(&rxe->mcg_lock); - rxe_drop_ref(mcg); /* drop ref from rxe_pool_get_key. */ + rxe_drop_ref(mcg); if (likely(!skb)) return; diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h index 3790163..caa5b1b 100644 --- a/drivers/infiniband/sw/rxe/rxe_verbs.h +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h @@ -353,6 +353,7 @@ struct rxe_mw { struct rxe_mcg { struct rxe_pool_elem elem; + struct rb_node node; struct rxe_dev *rxe; struct list_head qp_list; union ib_gid mgid; @@ -396,7 +397,10 @@ struct rxe_dev { struct rxe_pool mw_pool; struct rxe_pool mc_grp_pool; + /* multicast support */ spinlock_t mcg_lock; + struct rb_root mcg_tree; + atomic_t mcg_num; spinlock_t pending_lock; /* guard pending_mmaps */ struct list_head pending_mmaps; @@ -477,6 +481,4 @@ static inline struct rxe_pd *rxe_mw_pd(struct rxe_mw *mw) int rxe_register_device(struct rxe_dev *rxe, const char *ibdev_name); -void rxe_mc_cleanup(struct rxe_pool_elem *elem); - #endif /* RXE_VERBS_H */ -- 2.7.4