[PATCH AUTOSEL 4.20 109/304] nfp: add locking around representor changes

Sasha Levin
2019-01-28T15:48:37Z

From: Jakub Kicinski <jakub.kicinski@netronome.com>

[ Upstream commit 71844fac1ed459024dd2a448d63d5b28b8c87daa ]

Up until now we never needed to keep a networking locks around
representors accesses, we only accessed them when device was
reconfigured (under nfp pf->lock) or on fast path (under RCU).
Now we want to be able to iterate over all representors during
notifications, so make sure representor assignment is done
under RTNL lock.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/netronome/nfp/abm/main.c | 4 ++++
drivers/net/ethernet/netronome/nfp/nfp_app.c | 2 ++
drivers/net/ethernet/netronome/nfp/nfp_net_repr.c | 2 ++
3 files changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/netronome/nfp/abm/main.c b/drivers/net/ethernet/netronome/nfp/abm/main.c
index c0830c0c2c3f..376df412ea55 100644
--- a/drivers/net/ethernet/netronome/nfp/abm/main.c
+++ b/drivers/net/ethernet/netronome/nfp/abm/main.c
@@ -384,7 +384,9 @@ nfp_abm_spawn_repr(struct nfp_app *app, struct nfp_abm_link *alink,

reprs = nfp_reprs_get_locked(app, rtype);
WARN(nfp_repr_get_locked(app, reprs, alink->id), "duplicate repr");
+ rtnl_lock();
rcu_assign_pointer(reprs->reprs[alink->id], netdev);
+ rtnl_unlock();

nfp_info(app->cpp, "%s Port %d Representor(%s) created\n",
ptype == NFP_PORT_PF_PORT ? "PCIe" : "Phys",
@@ -410,7 +412,9 @@ nfp_abm_kill_repr(struct nfp_app *app, struct nfp_abm_link *alink,
netdev = nfp_repr_get_locked(app, reprs, alink->id);
if (!netdev)
return;
+ rtnl_lock();
rcu_assign_pointer(reprs->reprs[alink->id], NULL);
+ rtnl_unlock();
synchronize_rcu();
/* Cast to make sure nfp_repr_clean_and_free() takes a nfp_repr */
nfp_repr_clean_and_free((struct nfp_repr *)netdev_priv(netdev));
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_app.c b/drivers/net/ethernet/netronome/nfp/nfp_app.c
index 68a0991aac22..3bd1386162b9 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_app.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_app.c
@@ -131,7 +131,9 @@ nfp_app_reprs_set(struct nfp_app *app, enum nfp_repr_type type,
struct nfp_reprs *old;

old = nfp_reprs_get_locked(app, type);
+ rtnl_lock();
rcu_assign_pointer(app->reprs[type], reprs);
+ rtnl_unlock();

return old;
}
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c
index c09b893c30dd..0cf3f40eb8cf 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c
@@ -442,7 +442,9 @@ int nfp_reprs_resync_phys_ports(struct nfp_app *app)
continue;

nfp_app_repr_preclean(app, netdev);
+ rtnl_lock();
rcu_assign_pointer(reprs->reprs[i], NULL);
+ rtnl_unlock();
synchronize_rcu();
nfp_repr_clean(repr);
}
--
2.19.1