From 6b8417b7e6f5e4da2bfb4dd087d5f7f082d077de Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 12 Nov 2018 14:58:15 -0800 Subject: [PATCH] nfp: abm: build full Qdisc hierarchy based on graft notifications Using graft notifications recreate in the driver the full Qdisc hierarchy. Keep track of how many times each Qdisc is attached to the hierarchy to make sure we don't offload Qdiscs which are attached multiple times (device queues can't be shared). For graft events of Qdiscs we don't know exist make the child as invalid/untracked. Note that MQ Qdisc doesn't send destruction events reliably when device is dismantled, so we need to manually clean out the children otherwise we'd think Qdiscs which are still in use are getting freed. Signed-off-by: Jakub Kicinski Reviewed-by: John Hurley Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/abm/main.h | 2 + drivers/net/ethernet/netronome/nfp/abm/qdisc.c | 105 +++++++++++++++++++++++++ 2 files changed, 107 insertions(+) diff --git a/drivers/net/ethernet/netronome/nfp/abm/main.h b/drivers/net/ethernet/netronome/nfp/abm/main.h index adffa36..daca93e 100644 --- a/drivers/net/ethernet/netronome/nfp/abm/main.h +++ b/drivers/net/ethernet/netronome/nfp/abm/main.h @@ -78,6 +78,8 @@ enum nfp_qdisc_type { NFP_QDISC_RED, }; +#define NFP_QDISC_UNTRACKED ((struct nfp_qdisc *)1UL) + /** * struct nfp_qdisc - tracked TC Qdisc * @netdev: netdev on which Qdisc was created diff --git a/drivers/net/ethernet/netronome/nfp/abm/qdisc.c b/drivers/net/ethernet/netronome/nfp/abm/qdisc.c index 3ecb630..151d2da 100644 --- a/drivers/net/ethernet/netronome/nfp/abm/qdisc.c +++ b/drivers/net/ethernet/netronome/nfp/abm/qdisc.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) /* Copyright (C) 2018 Netronome Systems, Inc. */ +#include #include #include #include @@ -12,6 +13,66 @@ #include "../nfp_port.h" #include "main.h" +static bool nfp_abm_qdisc_child_valid(struct nfp_qdisc *qdisc, unsigned int id) +{ + return qdisc->children[id] && + qdisc->children[id] != NFP_QDISC_UNTRACKED; +} + +static void *nfp_abm_qdisc_tree_deref_slot(void __rcu **slot) +{ + return rtnl_dereference(*slot); +} + +static void +nfp_abm_qdisc_unlink_children(struct nfp_qdisc *qdisc, + unsigned int start, unsigned int end) +{ + unsigned int i; + + for (i = start; i < end; i++) + if (nfp_abm_qdisc_child_valid(qdisc, i)) { + qdisc->children[i]->use_cnt--; + qdisc->children[i] = NULL; + } +} + +static void +nfp_abm_qdisc_clear_mq(struct net_device *netdev, struct nfp_abm_link *alink, + struct nfp_qdisc *qdisc) +{ + struct radix_tree_iter iter; + unsigned int mq_refs = 0; + void __rcu **slot; + + if (!qdisc->use_cnt) + return; + /* MQ doesn't notify well on destruction, we need special handling of + * MQ's children. + */ + if (qdisc->type == NFP_QDISC_MQ && + qdisc == alink->root_qdisc && + netdev->reg_state == NETREG_UNREGISTERING) + return; + + /* Count refs held by MQ instances and clear pointers */ + radix_tree_for_each_slot(slot, &alink->qdiscs, &iter, 0) { + struct nfp_qdisc *mq = nfp_abm_qdisc_tree_deref_slot(slot); + unsigned int i; + + if (mq->type != NFP_QDISC_MQ || mq->netdev != netdev) + continue; + for (i = 0; i < mq->num_children; i++) + if (mq->children[i] == qdisc) { + mq->children[i] = NULL; + mq_refs++; + } + } + + WARN(qdisc->use_cnt != mq_refs, "non-zero qdisc use count: %d (- %d)\n", + qdisc->use_cnt, mq_refs); +} + static void nfp_abm_offload_compile_red(struct nfp_abm_link *alink, struct nfp_red_qdisc *qdisc, unsigned int queue) @@ -70,6 +131,7 @@ nfp_abm_qdisc_free(struct net_device *netdev, struct nfp_abm_link *alink, if (!qdisc) return; + nfp_abm_qdisc_clear_mq(netdev, alink, qdisc); WARN_ON(radix_tree_delete(&alink->qdiscs, TC_H_MAJ(qdisc->handle)) != qdisc); @@ -152,12 +214,44 @@ nfp_abm_qdisc_destroy(struct net_device *netdev, struct nfp_abm_link *alink, if (!qdisc) return; + /* We don't get TC_SETUP_ROOT_QDISC w/ MQ when netdev is unregistered */ + if (alink->root_qdisc == qdisc) + qdisc->use_cnt--; + + nfp_abm_qdisc_unlink_children(qdisc, 0, qdisc->num_children); nfp_abm_qdisc_free(netdev, alink, qdisc); if (alink->root_qdisc == qdisc) alink->root_qdisc = NULL; } +static int +nfp_abm_qdisc_graft(struct nfp_abm_link *alink, u32 handle, u32 child_handle, + unsigned int id) +{ + struct nfp_qdisc *parent, *child; + + parent = nfp_abm_qdisc_find(alink, handle); + if (!parent) + return 0; + + if (WARN(id >= parent->num_children, + "graft child out of bound %d >= %d\n", + id, parent->num_children)) + return -EINVAL; + + nfp_abm_qdisc_unlink_children(parent, id, id + 1); + + child = nfp_abm_qdisc_find(alink, child_handle); + if (child) + child->use_cnt++; + else + child = NFP_QDISC_UNTRACKED; + parent->children[id] = child; + + return 0; +} + static void __nfp_abm_reset_root(struct net_device *netdev, struct nfp_abm_link *alink, u32 handle, unsigned int qs, u32 init_val) @@ -404,6 +498,9 @@ int nfp_abm_setup_tc_red(struct net_device *netdev, struct nfp_abm_link *alink, return nfp_abm_red_stats(alink, opt); case TC_RED_XSTATS: return nfp_abm_red_xstats(alink, opt); + case TC_RED_GRAFT: + return nfp_abm_qdisc_graft(alink, opt->handle, + opt->child_handle, 0); default: return -EOPNOTSUPP; } @@ -460,6 +557,10 @@ int nfp_abm_setup_tc_mq(struct net_device *netdev, struct nfp_abm_link *alink, return 0; case TC_MQ_STATS: return nfp_abm_mq_stats(alink, opt); + case TC_MQ_GRAFT: + return nfp_abm_qdisc_graft(alink, opt->handle, + opt->graft_params.child_handle, + opt->graft_params.queue); default: return -EOPNOTSUPP; } @@ -470,7 +571,11 @@ int nfp_abm_setup_root(struct net_device *netdev, struct nfp_abm_link *alink, { if (opt->ingress) return -EOPNOTSUPP; + if (alink->root_qdisc) + alink->root_qdisc->use_cnt--; alink->root_qdisc = nfp_abm_qdisc_find(alink, opt->handle); + if (alink->root_qdisc) + alink->root_qdisc->use_cnt++; return 0; } -- 2.7.4