diff --git a/drivers/infiniband/hw/cxgb3/iwch.c b/drivers/infiniband/hw/cxgb3/iwch.c
index 1f479ad4fde6..76dfcdc42df3 100644
--- a/drivers/infiniband/hw/cxgb3/iwch.c
+++ b/drivers/infiniband/hw/cxgb3/iwch.c
@@ -100,8 +100,7 @@ static void rnic_init(struct iwch_dev *rnicp)
 	pr_debug("%s iwch_dev %p\n", __func__,  rnicp);
 	xa_init_flags(&rnicp->cqs, XA_FLAGS_LOCK_IRQ);
 	xa_init_flags(&rnicp->qps, XA_FLAGS_LOCK_IRQ);
-	idr_init(&rnicp->mmidr);
-	spin_lock_init(&rnicp->lock);
+	xa_init_flags(&rnicp->mrs, XA_FLAGS_LOCK_IRQ);
 	INIT_DELAYED_WORK(&rnicp->db_drop_task, iwch_db_drop_task);
 
 	rnicp->attr.max_qps = T3_MAX_NUM_QP - 32;
@@ -183,7 +182,6 @@ static void close_rnic_dev(struct t3cdev *tdev)
 			list_del(&dev->entry);
 			iwch_unregister_device(dev);
 			cxio_rdev_close(&dev->rdev);
-			idr_destroy(&dev->mmidr);
 			ib_dealloc_device(&dev->ibdev);
 			break;
 		}
diff --git a/drivers/infiniband/hw/cxgb3/iwch.h b/drivers/infiniband/hw/cxgb3/iwch.h
index 70e086946d30..310a937bffcf 100644
--- a/drivers/infiniband/hw/cxgb3/iwch.h
+++ b/drivers/infiniband/hw/cxgb3/iwch.h
@@ -35,7 +35,7 @@
 #include <linux/mutex.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
-#include <linux/idr.h>
+#include <linux/xarray.h>
 #include <linux/workqueue.h>
 
 #include <rdma/ib_verbs.h>
@@ -108,8 +108,7 @@ struct iwch_dev {
 	struct iwch_rnic_attributes attr;
 	struct xarray cqs;
 	struct xarray qps;
-	struct idr mmidr;
-	spinlock_t lock;
+	struct xarray mrs;
 	struct list_head entry;
 	struct delayed_work db_drop_task;
 };
@@ -146,30 +145,7 @@ static inline struct iwch_qp *get_qhp(struct iwch_dev *rhp, u32 qpid)
 
 static inline struct iwch_mr *get_mhp(struct iwch_dev *rhp, u32 mmid)
 {
-	return idr_find(&rhp->mmidr, mmid);
-}
-
-static inline int insert_handle(struct iwch_dev *rhp, struct idr *idr,
-				void *handle, u32 id)
-{
-	int ret;
-
-	idr_preload(GFP_KERNEL);
-	spin_lock_irq(&rhp->lock);
-
-	ret = idr_alloc(idr, handle, id, id + 1, GFP_NOWAIT);
-
-	spin_unlock_irq(&rhp->lock);
-	idr_preload_end();
-
-	return ret < 0 ? ret : 0;
-}
-
-static inline void remove_handle(struct iwch_dev *rhp, struct idr *idr, u32 id)
-{
-	spin_lock_irq(&rhp->lock);
-	idr_remove(idr, id);
-	spin_unlock_irq(&rhp->lock);
+	return xa_load(&rhp->mrs, mmid);
 }
 
 extern struct cxgb3_client t3c_client;
diff --git a/drivers/infiniband/hw/cxgb3/iwch_mem.c b/drivers/infiniband/hw/cxgb3/iwch_mem.c
index 12886b1b4b10..ce0f2741821d 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_mem.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_mem.c
@@ -49,7 +49,7 @@ static int iwch_finish_mem_reg(struct iwch_mr *mhp, u32 stag)
 	mmid = stag >> 8;
 	mhp->ibmr.rkey = mhp->ibmr.lkey = stag;
 	pr_debug("%s mmid 0x%x mhp %p\n", __func__, mmid, mhp);
-	return insert_handle(mhp->rhp, &mhp->rhp->mmidr, mhp, mmid);
+	return xa_insert_irq(&mhp->rhp->mrs, mmid, mhp, GFP_KERNEL);
 }
 
 int iwch_register_mem(struct iwch_dev *rhp, struct iwch_pd *php,
diff --git a/drivers/infiniband/hw/cxgb3/iwch_provider.c b/drivers/infiniband/hw/cxgb3/iwch_provider.c
index 76120fdf7d1b..04dc8ede36a9 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_provider.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_provider.c
@@ -430,7 +430,7 @@ static int iwch_dereg_mr(struct ib_mr *ib_mr)
 	cxio_dereg_mem(&rhp->rdev, mhp->attr.stag, mhp->attr.pbl_size,
 		       mhp->attr.pbl_addr);
 	iwch_free_pbl(mhp);
-	remove_handle(rhp, &rhp->mmidr, mmid);
+	xa_erase_irq(&rhp->mrs, mmid);
 	if (mhp->kva)
 		kfree((void *) (unsigned long) mhp->kva);
 	if (mhp->umem)
@@ -650,7 +650,7 @@ static struct ib_mw *iwch_alloc_mw(struct ib_pd *pd, enum ib_mw_type type,
 	mhp->attr.stag = stag;
 	mmid = (stag) >> 8;
 	mhp->ibmw.rkey = stag;
-	if (insert_handle(rhp, &rhp->mmidr, mhp, mmid)) {
+	if (xa_insert_irq(&rhp->mrs, mmid, mhp, GFP_KERNEL)) {
 		cxio_deallocate_window(&rhp->rdev, mhp->attr.stag);
 		kfree(mhp);
 		return ERR_PTR(-ENOMEM);
@@ -669,7 +669,7 @@ static int iwch_dealloc_mw(struct ib_mw *mw)
 	rhp = mhp->rhp;
 	mmid = (mw->rkey) >> 8;
 	cxio_deallocate_window(&rhp->rdev, mhp->attr.stag);
-	remove_handle(rhp, &rhp->mmidr, mmid);
+	xa_erase_irq(&rhp->mrs, mmid);
 	pr_debug("%s ib_mw %p mmid 0x%x ptr %p\n", __func__, mw, mmid, mhp);
 	kfree(mhp);
 	return 0;
@@ -715,7 +715,7 @@ static struct ib_mr *iwch_alloc_mr(struct ib_pd *pd,
 	mhp->attr.state = 1;
 	mmid = (stag) >> 8;
 	mhp->ibmr.rkey = mhp->ibmr.lkey = stag;
-	ret = insert_handle(rhp, &rhp->mmidr, mhp, mmid);
+	ret = xa_insert_irq(&rhp->mrs, mmid, mhp, GFP_KERNEL);
 	if (ret)
 		goto err3;
 
