ipv4: Use accessors for fib_info nexthop data

Use helpers to access fib_nh and fib_nhs fields of a fib_info. Drop the
fib_dev macro which is an alias for the first nexthop. Replacements:

  fi->fib_dev    --> fib_info_nh(fi, 0)->fib_nh_dev
  fi->fib_nh     --> fib_info_nh(fi, 0)
  fi->fib_nh[i]  --> fib_info_nh(fi, i)
  fi->fib_nhs    --> fib_info_num_path(fi)

where fib_info_nh(fi, i) returns fi->fib_nh[nhsel] and fib_info_num_path
returns fi->fib_nhs.

Move the existing fib_info_nhc to nexthop.h and define the new ones
there. A later patch adds a check if a fib_info uses a nexthop object,
and defining the helpers in nexthop.h avoid circular header
dependencies.

After this all remaining open coded references to fi->fib_nhs and
fi->fib_nh are in:
- fib_create_info and helpers used to lookup an existing fib_info
  entry, and
- the netdev event functions fib_sync_down_dev and fib_sync_up.

The latter two will not be reused for nexthops, and the fib_create_info
will be updated to handle a nexthop in a fib_info.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 19 insertions, 10 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag_mp.c b/drivers/net/ethernet/mellanox/mlx5/core/lag_mp.c
index 8212bfd05733..2cbfaa8da7fc 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lag_mp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lag_mp.c
@@ -2,6 +2,7 @@
 /* Copyright (c) 2019 Mellanox Technologies. */
 
 #include <linux/netdevice.h>
+#include <net/nexthop.h>
 #include "lag.h"
 #include "lag_mp.h"
 #include "mlx5_core.h"
@@ -110,6 +111,8 @@ static void mlx5_lag_fib_route_event(struct mlx5_lag *ldev,
 				     struct fib_info *fi)
 {
 	struct lag_mp *mp = &ldev->lag_mp;
+	struct fib_nh *fib_nh0, *fib_nh1;
+	unsigned int nhs;
 
 	/* Handle delete event */
 	if (event == FIB_EVENT_ENTRY_DEL) {
@@ -120,9 +123,11 @@ static void mlx5_lag_fib_route_event(struct mlx5_lag *ldev,
 	}
 
 	/* Handle add/replace event */
-	if (fi->fib_nhs == 1) {
+	nhs = fib_info_num_path(fi);
+	if (nhs == 1) {
 		if (__mlx5_lag_is_active(ldev)) {
-			struct net_device *nh_dev = fi->fib_nh[0].fib_nh_dev;
+			struct fib_nh *nh = fib_info_nh(fi, 0);
+			struct net_device *nh_dev = nh->fib_nh_dev;
 			int i = mlx5_lag_dev_get_netdev_idx(ldev, nh_dev);
 
 			mlx5_lag_set_port_affinity(ldev, ++i);
@@ -130,14 +135,16 @@ static void mlx5_lag_fib_route_event(struct mlx5_lag *ldev,
 		return;
 	}
 
-	if (fi->fib_nhs != 2)
+	if (nhs != 2)
 		return;
 
 	/* Verify next hops are ports of the same hca */
-	if (!(fi->fib_nh[0].fib_nh_dev == ldev->pf[0].netdev &&
-	      fi->fib_nh[1].fib_nh_dev == ldev->pf[1].netdev) &&
-	    !(fi->fib_nh[0].fib_nh_dev == ldev->pf[1].netdev &&
-	      fi->fib_nh[1].fib_nh_dev == ldev->pf[0].netdev)) {
+	fib_nh0 = fib_info_nh(fi, 0);
+	fib_nh1 = fib_info_nh(fi, 1);
+	if (!(fib_nh0->fib_nh_dev == ldev->pf[0].netdev &&
+	      fib_nh1->fib_nh_dev == ldev->pf[1].netdev) &&
+	    !(fib_nh0->fib_nh_dev == ldev->pf[1].netdev &&
+	      fib_nh1->fib_nh_dev == ldev->pf[0].netdev)) {
 		mlx5_core_warn(ldev->pf[0].dev, "Multipath offload require two ports of the same HCA\n");
 		return;
 	}
@@ -174,7 +181,7 @@ static void mlx5_lag_fib_nexthop_event(struct mlx5_lag *ldev,
 			mlx5_lag_set_port_affinity(ldev, i);
 		}
 	} else if (event == FIB_EVENT_NH_ADD &&
-		   fi->fib_nhs == 2) {
+		   fib_info_num_path(fi) == 2) {
 		mlx5_lag_set_port_affinity(ldev, 0);
 	}
 }
@@ -238,6 +245,7 @@ static int mlx5_lag_fib_event(struct notifier_block *nb,
 	struct mlx5_fib_event_work *fib_work;
 	struct fib_entry_notifier_info *fen_info;
 	struct fib_nh_notifier_info *fnh_info;
+	struct net_device *fib_dev;
 	struct fib_info *fi;
 
 	if (info->family != AF_INET)
@@ -254,8 +262,9 @@ static int mlx5_lag_fib_event(struct notifier_block *nb,
 		fen_info = container_of(info, struct fib_entry_notifier_info,
 					info);
 		fi = fen_info->fi;
-		if (fi->fib_dev != ldev->pf[0].netdev &&
-		    fi->fib_dev != ldev->pf[1].netdev) {
+		fib_dev = fib_info_nh(fen_info->fi, 0)->fib_nh_dev;
+		if (fib_dev != ldev->pf[0].netdev &&
+		    fib_dev != ldev->pf[1].netdev) {
 			return NOTIFY_DONE;
 		}
 		fib_work = mlx5_lag_init_fib_work(ldev, event);