[PATCH 05/38] mlx5: Convert mlx5_qp_table to XArray

[Matthew Wilcox <willy@infradead.org>]

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

Fix the locking in destroy_resource_common() to be irq-disable rather
than irq-save.  wait_for_completion() can sleep, so this function must
not be callable from interrupt context.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 drivers/net/ethernet/mellanox/mlx5/core/qp.c | 38 ++++++--------------
 include/linux/mlx5/driver.h                  |  8 ++---
 include/linux/mlx5/qp.h                      |  2 +-
 3 files changed, 13 insertions(+), 35 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/qp.c b/drivers/net/ethernet/mellanox/mlx5/core/qp.c
index b8ba74de9555..e3367290b5ce 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/qp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/qp.c
@@ -49,13 +49,11 @@ mlx5_get_rsc(struct mlx5_qp_table *table, u32 rsn)
 	struct mlx5_core_rsc_common *common;
 	unsigned long flags;
 
-	spin_lock_irqsave(&table->lock, flags);
-
-	common = radix_tree_lookup(&table->tree, rsn);
+	xa_lock_irqsave(&table->array, flags);
+	common = xa_load(&table->array, rsn);
 	if (common)
 		atomic_inc(&common->refcount);
-
-	spin_unlock_irqrestore(&table->lock, flags);
+	xa_unlock_irqrestore(&table->array, flags);
 
 	return common;
 }
@@ -197,35 +195,22 @@ static int create_resource_common(struct mlx5_core_dev *dev,
 				  struct mlx5_core_qp *qp,
 				  int rsc_type)
 {
-	struct mlx5_qp_table *table = &dev->priv.qp_table;
-	int err;
-
-	qp->common.res = rsc_type;
-	spin_lock_irq(&table->lock);
-	err = radix_tree_insert(&table->tree,
-				qp->qpn | (rsc_type << MLX5_USER_INDEX_LEN),
-				qp);
-	spin_unlock_irq(&table->lock);
-	if (err)
-		return err;
-
 	atomic_set(&qp->common.refcount, 1);
 	init_completion(&qp->common.free);
 	qp->pid = current->pid;
 
-	return 0;
+	qp->common.res = rsc_type;
+	return xa_err(xa_store_irq(&dev->priv.qp_table.array,
+				qp->qpn | (rsc_type << MLX5_USER_INDEX_LEN),
+				qp, GFP_KERNEL));
 }
 
 static void destroy_resource_common(struct mlx5_core_dev *dev,
 				    struct mlx5_core_qp *qp)
 {
-	struct mlx5_qp_table *table = &dev->priv.qp_table;
-	unsigned long flags;
+	struct xarray *xa = &dev->priv.qp_table.array;
 
-	spin_lock_irqsave(&table->lock, flags);
-	radix_tree_delete(&table->tree,
-			  qp->qpn | (qp->common.res << MLX5_USER_INDEX_LEN));
-	spin_unlock_irqrestore(&table->lock, flags);
+	xa_erase_irq(xa, qp->qpn | (qp->common.res << MLX5_USER_INDEX_LEN));
 	mlx5_core_put_rsc((struct mlx5_core_rsc_common *)qp);
 	wait_for_completion(&qp->common.free);
 }
@@ -524,10 +509,7 @@ EXPORT_SYMBOL_GPL(mlx5_core_qp_modify);
 void mlx5_init_qp_table(struct mlx5_core_dev *dev)
 {
 	struct mlx5_qp_table *table = &dev->priv.qp_table;
-
-	memset(table, 0, sizeof(*table));
-	spin_lock_init(&table->lock);
-	INIT_RADIX_TREE(&table->tree, GFP_ATOMIC);
+	xa_init_flags(&table->array, XA_FLAGS_LOCK_IRQ);
 	mlx5_qp_debugfs_init(dev);
 
 	table->nb.notifier_call = rsc_event_notifier;
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index df23f17eed64..ba8f59b11920 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -448,12 +448,8 @@ struct mlx5_core_health {
 };
 
 struct mlx5_qp_table {
-	struct notifier_block   nb;
-
-	/* protect radix tree
-	 */
-	spinlock_t		lock;
-	struct radix_tree_root	tree;
+	struct notifier_block	nb;
+	struct xarray		array;
 };
 
 struct mlx5_vf_context {
diff --git a/include/linux/mlx5/qp.h b/include/linux/mlx5/qp.h
index ae63b1ae9004..6d1577a1ca41 100644
--- a/include/linux/mlx5/qp.h
+++ b/include/linux/mlx5/qp.h
@@ -555,7 +555,7 @@ struct mlx5_qp_context {
 
 static inline struct mlx5_core_qp *__mlx5_qp_lookup(struct mlx5_core_dev *dev, u32 qpn)
 {
-	return radix_tree_lookup(&dev->priv.qp_table.tree, qpn);
+	return xa_load(&dev->priv.qp_table.array, qpn);
 }
 
 int mlx5_core_create_dct(struct mlx5_core_dev *dev,
-- 
2.23.0.rc1