[PATCH net-next 04/12] nfp: add nfp_reprs_get_locked() helper

[Jakub Kicinski]

The write side of repr tables is always done under pf->lock.
Add a helper to dereference repr table pointers under protection
of that lock.

Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vanderme...@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_app.c      | 12 ++++++++++--
 drivers/net/ethernet/netronome/nfp/nfp_app.h      |  2 ++
 drivers/net/ethernet/netronome/nfp/nfp_net_repr.c |  4 +---
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_app.c 
b/drivers/net/ethernet/netronome/nfp/nfp_app.c
index 955a9f44d244..8ce65d4276b1 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_app.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_app.c
@@ -32,6 +32,8 @@
  */
 
 #include <linux/bug.h>
+#include <linux/lockdep.h>
+#include <linux/rcupdate.h>
 #include <linux/skbuff.h>
 #include <linux/slab.h>
 
@@ -98,14 +100,20 @@ nfp_app_ctrl_msg_alloc(struct nfp_app *app, unsigned int 
size, gfp_t priority)
        return skb;
 }
 
+struct nfp_reprs *
+nfp_reprs_get_locked(struct nfp_app *app, enum nfp_repr_type type)
+{
+       return rcu_dereference_protected(app->reprs[type],
+                                        lockdep_is_held(&app->pf->lock));
+}
+
 struct nfp_reprs *
 nfp_app_reprs_set(struct nfp_app *app, enum nfp_repr_type type,
                  struct nfp_reprs *reprs)
 {
        struct nfp_reprs *old;
 
-       old = rcu_dereference_protected(app->reprs[type],
-                                       lockdep_is_held(&app->pf->lock));
+       old = nfp_reprs_get_locked(app, type);
        rcu_assign_pointer(app->reprs[type], reprs);
 
        return old;
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_app.h 
b/drivers/net/ethernet/netronome/nfp/nfp_app.h
index 6a6eb02b516e..91d469a8e3e6 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_app.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_app.h
@@ -384,6 +384,8 @@ static inline struct net_device *nfp_app_repr_get(struct 
nfp_app *app, u32 id)
 
 struct nfp_app *nfp_app_from_netdev(struct net_device *netdev);
 
+struct nfp_reprs *
+nfp_reprs_get_locked(struct nfp_app *app, enum nfp_repr_type type);
 struct nfp_reprs *
 nfp_app_reprs_set(struct nfp_app *app, enum nfp_repr_type type,
                  struct nfp_reprs *reprs);
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c 
b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c
index 317f87cc3cc6..e2452176fa23 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c
@@ -424,9 +424,7 @@ int nfp_reprs_resync_phys_ports(struct nfp_app *app)
        struct nfp_repr *repr;
        int i;
 
-       old_reprs =
-               rcu_dereference_protected(app->reprs[NFP_REPR_TYPE_PHYS_PORT],
-                                         lockdep_is_held(&app->pf->lock));
+       old_reprs = nfp_reprs_get_locked(app, NFP_REPR_TYPE_PHYS_PORT);
        if (!old_reprs)
                return 0;
 
-- 
2.15.1