net/mlx4_core: Change resource tracking mechanism to use red-black tree

Change the data structure used for managing the SRIOV resource tracking
mechanism from radix tree to red-black tree. This is preparation step
for supporting resource IDs which are 64bit long, such as network flow
steering rules. Such IDs can't be used as radix-tree keys on 32bit
architectures and hence the reason for the change.

Signed-off-by: Hadar Hen Zion <hadarh@mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/mlx4.h

@@ -39,6 +39,7 @@
 
 #include <linux/mutex.h>
 #include <linux/radix-tree.h>
+#include <linux/rbtree.h>
 #include <linux/timer.h>
 #include <linux/semaphore.h>
 #include <linux/workqueue.h>
@@ -509,7 +510,7 @@ struct slave_list {
 struct mlx4_resource_tracker {
 	spinlock_t lock;
 	/* tree for each resources */
-	struct radix_tree_root res_tree[MLX4_NUM_OF_RESOURCE_TYPE];
+	struct rb_root res_tree[MLX4_NUM_OF_RESOURCE_TYPE];
 	/* num_of_slave's lists, one per slave */
 	struct slave_list *slave_list;
 };

drivers/net/ethernet/mellanox/mlx4/resource_tracker.c

@@ -57,6 +57,7 @@ struct mac_res {
 
 struct res_common {
 	struct list_head	list;
+	struct rb_node		node;
 	u32		        res_id;
 	int			owner;
 	int			state;
@@ -189,6 +190,49 @@ struct res_xrcdn {
 	int			port;
 };
 
+static void *res_tracker_lookup(struct rb_root *root, u64 res_id)
+{
+	struct rb_node *node = root->rb_node;
+
+	while (node) {
+		struct res_common *res = container_of(node, struct res_common,
+						      node);
+
+		if (res_id < res->res_id)
+			node = node->rb_left;
+		else if (res_id > res->res_id)
+			node = node->rb_right;
+		else
+			return res;
+	}
+	return NULL;
+}
+
+static int res_tracker_insert(struct rb_root *root, struct res_common *res)
+{
+	struct rb_node **new = &(root->rb_node), *parent = NULL;
+
+	/* Figure out where to put new node */
+	while (*new) {
+		struct res_common *this = container_of(*new, struct res_common,
+						       node);
+
+		parent = *new;
+		if (res->res_id < this->res_id)
+			new = &((*new)->rb_left);
+		else if (res->res_id > this->res_id)
+			new = &((*new)->rb_right);
+		else
+			return -EEXIST;
+	}
+
+	/* Add new node and rebalance tree. */
+	rb_link_node(&res->node, parent, new);
+	rb_insert_color(&res->node, root);
+
+	return 0;
+}
+
 /* For Debug uses */
 static const char *ResourceType(enum mlx4_resource rt)
 {
@@ -228,8 +272,7 @@ int mlx4_init_resource_tracker(struct mlx4_dev *dev)
 	mlx4_dbg(dev, "Started init_resource_tracker: %ld slaves\n",
 		 dev->num_slaves);
 	for (i = 0 ; i < MLX4_NUM_OF_RESOURCE_TYPE; i++)
-		INIT_RADIX_TREE(&priv->mfunc.master.res_tracker.res_tree[i],
-				GFP_ATOMIC|__GFP_NOWARN);
+		priv->mfunc.master.res_tracker.res_tree[i] = RB_ROOT;
 
 	spin_lock_init(&priv->mfunc.master.res_tracker.lock);
 	return 0 ;
@@ -277,8 +320,8 @@ static void *find_res(struct mlx4_dev *dev, int res_id,
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
 
-	return radix_tree_lookup(&priv->mfunc.master.res_tracker.res_tree[type],
-				 res_id);
+	return res_tracker_lookup(&priv->mfunc.master.res_tracker.res_tree[type],
+				  res_id);
 }
 
 static int get_res(struct mlx4_dev *dev, int slave, int res_id,
@@ -523,7 +566,7 @@ static int add_res_range(struct mlx4_dev *dev, int slave, int base, int count,
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	struct res_common **res_arr;
 	struct mlx4_resource_tracker *tracker = &priv->mfunc.master.res_tracker;
-	struct radix_tree_root *root = &tracker->res_tree[type];
+	struct rb_root *root = &tracker->res_tree[type];
 
 	res_arr = kzalloc(count * sizeof *res_arr, GFP_KERNEL);
 	if (!res_arr)
@@ -546,7 +589,7 @@ static int add_res_range(struct mlx4_dev *dev, int slave, int base, int count,
 			err = -EEXIST;
 			goto undo;
 		}
-		err = radix_tree_insert(root, base + i, res_arr[i]);
+		err = res_tracker_insert(root, res_arr[i]);
 		if (err)
 			goto undo;
 		list_add_tail(&res_arr[i]->list,
@@ -559,7 +602,7 @@ static int add_res_range(struct mlx4_dev *dev, int slave, int base, int count,
 
 undo:
 	for (--i; i >= base; --i)
-		radix_tree_delete(&tracker->res_tree[type], i);
+		rb_erase(&res_arr[i]->node, root);
 
 	spin_unlock_irq(mlx4_tlock(dev));
 
@@ -695,7 +738,7 @@ static int rem_res_range(struct mlx4_dev *dev, int slave, int base, int count,
 
 	spin_lock_irq(mlx4_tlock(dev));
 	for (i = base; i < base + count; ++i) {
-		r = radix_tree_lookup(&tracker->res_tree[type], i);
+		r = res_tracker_lookup(&tracker->res_tree[type], i);
 		if (!r) {
 			err = -ENOENT;
 			goto out;
@@ -710,8 +753,8 @@ static int rem_res_range(struct mlx4_dev *dev, int slave, int base, int count,
 	}
 
 	for (i = base; i < base + count; ++i) {
-		r = radix_tree_lookup(&tracker->res_tree[type], i);
-		radix_tree_delete(&tracker->res_tree[type], i);
+		r = res_tracker_lookup(&tracker->res_tree[type], i);
+		rb_erase(&r->node, &tracker->res_tree[type]);
 		list_del(&r->list);
 		kfree(r);
 	}
@@ -733,7 +776,7 @@ static int qp_res_start_move_to(struct mlx4_dev *dev, int slave, int qpn,
 	int err = 0;
 
 	spin_lock_irq(mlx4_tlock(dev));
-	r = radix_tree_lookup(&tracker->res_tree[RES_QP], qpn);
+	r = res_tracker_lookup(&tracker->res_tree[RES_QP], qpn);
 	if (!r)
 		err = -ENOENT;
 	else if (r->com.owner != slave)
@@ -797,7 +840,7 @@ static int mr_res_start_move_to(struct mlx4_dev *dev, int slave, int index,
 	int err = 0;
 
 	spin_lock_irq(mlx4_tlock(dev));
-	r = radix_tree_lookup(&tracker->res_tree[RES_MPT], index);
+	r = res_tracker_lookup(&tracker->res_tree[RES_MPT], index);
 	if (!r)
 		err = -ENOENT;
 	else if (r->com.owner != slave)
@@ -850,7 +893,7 @@ static int eq_res_start_move_to(struct mlx4_dev *dev, int slave, int index,
 	int err = 0;
 
 	spin_lock_irq(mlx4_tlock(dev));
-	r = radix_tree_lookup(&tracker->res_tree[RES_EQ], index);
+	r = res_tracker_lookup(&tracker->res_tree[RES_EQ], index);
 	if (!r)
 		err = -ENOENT;
 	else if (r->com.owner != slave)
@@ -898,7 +941,7 @@ static int cq_res_start_move_to(struct mlx4_dev *dev, int slave, int cqn,
 	int err;
 
 	spin_lock_irq(mlx4_tlock(dev));
-	r = radix_tree_lookup(&tracker->res_tree[RES_CQ], cqn);
+	r = res_tracker_lookup(&tracker->res_tree[RES_CQ], cqn);
 	if (!r)
 		err = -ENOENT;
 	else if (r->com.owner != slave)
@@ -952,7 +995,7 @@ static int srq_res_start_move_to(struct mlx4_dev *dev, int slave, int index,
 	int err = 0;
 
 	spin_lock_irq(mlx4_tlock(dev));
-	r = radix_tree_lookup(&tracker->res_tree[RES_SRQ], index);
+	r = res_tracker_lookup(&tracker->res_tree[RES_SRQ], index);
 	if (!r)
 		err = -ENOENT;
 	else if (r->com.owner != slave)
@@ -1001,7 +1044,7 @@ static void res_abort_move(struct mlx4_dev *dev, int slave,
 	struct res_common *r;
 
 	spin_lock_irq(mlx4_tlock(dev));
-	r = radix_tree_lookup(&tracker->res_tree[type], id);
+	r = res_tracker_lookup(&tracker->res_tree[type], id);
 	if (r && (r->owner == slave))
 		r->state = r->from_state;
 	spin_unlock_irq(mlx4_tlock(dev));
@@ -1015,7 +1058,7 @@ static void res_end_move(struct mlx4_dev *dev, int slave,
 	struct res_common *r;
 
 	spin_lock_irq(mlx4_tlock(dev));
-	r = radix_tree_lookup(&tracker->res_tree[type], id);
+	r = res_tracker_lookup(&tracker->res_tree[type], id);
 	if (r && (r->owner == slave))
 		r->state = r->to_state;
 	spin_unlock_irq(mlx4_tlock(dev));
@@ -2817,8 +2860,8 @@ static void rem_slave_qps(struct mlx4_dev *dev, int slave)
 				switch (state) {
 				case RES_QP_RESERVED:
 					spin_lock_irq(mlx4_tlock(dev));
-					radix_tree_delete(&tracker->res_tree[RES_QP],
-							  qp->com.res_id);
+					rb_erase(&qp->com.node,
+						 &tracker->res_tree[RES_QP]);
 					list_del(&qp->com.list);
 					spin_unlock_irq(mlx4_tlock(dev));
 					kfree(qp);
@@ -2888,8 +2931,8 @@ static void rem_slave_srqs(struct mlx4_dev *dev, int slave)
 				case RES_SRQ_ALLOCATED:
 					__mlx4_srq_free_icm(dev, srqn);
 					spin_lock_irq(mlx4_tlock(dev));
-					radix_tree_delete(&tracker->res_tree[RES_SRQ],
-							  srqn);
+					rb_erase(&srq->com.node,
+						 &tracker->res_tree[RES_SRQ]);
 					list_del(&srq->com.list);
 					spin_unlock_irq(mlx4_tlock(dev));
 					kfree(srq);
@@ -2954,8 +2997,8 @@ static void rem_slave_cqs(struct mlx4_dev *dev, int slave)
 				case RES_CQ_ALLOCATED:
 					__mlx4_cq_free_icm(dev, cqn);
 					spin_lock_irq(mlx4_tlock(dev));
-					radix_tree_delete(&tracker->res_tree[RES_CQ],
-							  cqn);
+					rb_erase(&cq->com.node,
+						 &tracker->res_tree[RES_CQ]);
 					list_del(&cq->com.list);
 					spin_unlock_irq(mlx4_tlock(dev));
 					kfree(cq);
@@ -3017,8 +3060,8 @@ static void rem_slave_mrs(struct mlx4_dev *dev, int slave)
 				case RES_MPT_RESERVED:
 					__mlx4_mr_release(dev, mpt->key);
 					spin_lock_irq(mlx4_tlock(dev));
-					radix_tree_delete(&tracker->res_tree[RES_MPT],
-							  mptn);
+					rb_erase(&mpt->com.node,
+						 &tracker->res_tree[RES_MPT]);
 					list_del(&mpt->com.list);
 					spin_unlock_irq(mlx4_tlock(dev));
 					kfree(mpt);
@@ -3086,8 +3129,8 @@ static void rem_slave_mtts(struct mlx4_dev *dev, int slave)
 					__mlx4_free_mtt_range(dev, base,
 							      mtt->order);
 					spin_lock_irq(mlx4_tlock(dev));
-					radix_tree_delete(&tracker->res_tree[RES_MTT],
-							  base);
+					rb_erase(&mtt->com.node,
+						 &tracker->res_tree[RES_MTT]);
 					list_del(&mtt->com.list);
 					spin_unlock_irq(mlx4_tlock(dev));
 					kfree(mtt);
@@ -3133,8 +3176,8 @@ static void rem_slave_eqs(struct mlx4_dev *dev, int slave)
 				switch (state) {
 				case RES_EQ_RESERVED:
 					spin_lock_irq(mlx4_tlock(dev));
-					radix_tree_delete(&tracker->res_tree[RES_EQ],
-							  eqn);
+					rb_erase(&eq->com.node,
+						 &tracker->res_tree[RES_EQ]);
 					list_del(&eq->com.list);
 					spin_unlock_irq(mlx4_tlock(dev));
 					kfree(eq);
@@ -3191,7 +3234,8 @@ static void rem_slave_counters(struct mlx4_dev *dev, int slave)
 	list_for_each_entry_safe(counter, tmp, counter_list, com.list) {
 		if (counter->com.owner == slave) {
 			index = counter->com.res_id;
-			radix_tree_delete(&tracker->res_tree[RES_COUNTER], index);
+			rb_erase(&counter->com.node,
+				 &tracker->res_tree[RES_COUNTER]);
 			list_del(&counter->com.list);
 			kfree(counter);
 			__mlx4_counter_free(dev, index);
@@ -3220,7 +3264,7 @@ static void rem_slave_xrcdns(struct mlx4_dev *dev, int slave)
 	list_for_each_entry_safe(xrcd, tmp, xrcdn_list, com.list) {
 		if (xrcd->com.owner == slave) {
 			xrcdn = xrcd->com.res_id;
-			radix_tree_delete(&tracker->res_tree[RES_XRCD], xrcdn);
+			rb_erase(&xrcd->com.node, &tracker->res_tree[RES_XRCD]);
 			list_del(&xrcd->com.list);
 			kfree(xrcd);
 			__mlx4_xrcd_free(dev, xrcdn);