nexthop: Add support code for resilient ECMP groups [xxx]

drivers/net/netdevsim/fib.c

@@ -855,6 +855,27 @@ static void nsim_fib_dump_inconsistent(struct notifier_block *nb)
 	data->ipv6.rules.num = 0ULL;
 }
 
+static void nsim_nexthop_res_table_dump(u16 grp_id,
+					struct nh_notifier_res_table_info *info)
+{
+	u32 i;
+
+	printk(KERN_WARNING "res_table %d, %d buckets:\n",
+	       grp_id, info->num_nh_buckets);
+	for (i = 0; i < info->num_nh_buckets; i++)
+		printk(KERN_WARNING "bucket %d: NH %pI4\n",
+		       i, &info->nhs[i].ipv4);
+}
+
+static void nsim_nexthop_res_bucket_dump(u16 grp_id,
+					 struct nh_notifier_res_bucket_info *info)
+{
+	printk(KERN_WARNING "res_table %d, res_bucket %d: NH %pI4 -> %pI4%s\n",
+	       grp_id, info->bucket_index,
+	       &info->old_nh.ipv4, &info->new_nh.ipv4,
+	       info->force ? " (force)" : "");
+}
+
 static struct nsim_nexthop *nsim_nexthop_create(struct nsim_fib_data *data,
 						struct nh_notifier_info *info)
 {
@@ -881,6 +902,7 @@ static struct nsim_nexthop *nsim_nexthop_create(struct nsim_fib_data *data,
 			occ += info->nh_grp->nh_entries[i].weight;
 		break;
 	case NH_NOTIFIER_INFO_TYPE_RES_TABLE:
+		nsim_nexthop_res_table_dump(info->id, info->nh_res_table);
 		occ = info->nh_res_table->num_nh_buckets;
 		nexthop->is_resilient = true;
 		break;
@@ -1036,6 +1058,8 @@ static void nsim_nexthop_remove(struct nsim_fib_data *data,
 static int nsim_nexthop_bucket_replace(struct nsim_fib_data *data,
 				       struct nh_notifier_info *info)
 {
+	nsim_nexthop_res_bucket_dump(info->id, info->nh_res_bucket);
+
 	if (data->fail_nexthop_bucket_replace) {
 		NL_SET_ERR_MSG_MOD(info->extack, "Failed to replace nexthop bucket");
 		return -EINVAL;

include/net/nexthop.h

@@ -40,6 +40,9 @@ struct nh_config {
 
 	struct nlattr	*nh_grp;
 	u16		nh_grp_type;
+	u32		nh_grp_res_num_buckets;
+	u32		nh_grp_res_idle_timer;
+	u32		nh_grp_res_unbalanced_timer;
 
 	struct nlattr	*nh_encap;
 	u16		nh_encap_type;
@@ -63,6 +66,30 @@ struct nh_info {
 	};
 };
 
+struct nh_res_bucket {
+	struct nh_grp_entry	*nh_entry;
+	atomic_long_t		used_time;
+	bool			occupied;
+	u8			nh_flags;
+};
+
+struct nh_res_table {
+	struct net		*net;
+	u32			nhg_id;
+	struct delayed_work 	upkeep_dw;
+
+	/* List of NHGEs that have too few buckets. Reclaimed buckets will
+	 * be given to entries in this list.
+	 */
+	struct list_head	uw_nh_entries;
+
+	u32			idle_timer;
+	u32			unbalanced_timer;
+
+	u16			num_nh_buckets;
+	struct nh_res_bucket	nh_buckets[];
+};
+
 struct nh_grp_entry {
 	struct nexthop	*nh;
 	u8		weight;
@@ -71,6 +98,15 @@ struct nh_grp_entry {
 		struct {
 			atomic_t	upper_bound;
 		} mpath;
+		struct {
+			/* Member on uw_nh_entries. */
+			struct list_head	uw_nh_entry;
+
+			bool			in_reserve;
+			unsigned long		reserve_time;
+			u16			count_buckets;
+			u16			wants_buckets;
+		} res;
 	};
 
 	struct list_head nh_list;
@@ -81,8 +117,11 @@ struct nh_group {
 	struct nh_group		*spare; /* spare group for removals */
 	u16			num_nh;
 	bool			mpath;
+	bool			resilient;
 	bool			fdb_nh;
 	bool			has_v4;
+
+	struct nh_res_table __rcu *res_table;
 	struct nh_grp_entry	nh_entries[];
 };