diff --git a/drivers/infiniband/hw/cxgb4/device.c b/drivers/infiniband/hw/cxgb4/device.c
index 7dcf7740a732..4e9d5bd880d4 100644
--- a/drivers/infiniband/hw/cxgb4/device.c
+++ b/drivers/infiniband/hw/cxgb4/device.c
@@ -374,9 +374,8 @@ static const struct file_operations qp_debugfs_fops = {
 	.llseek  = default_llseek,
 };
 
-static int dump_stag(int id, void *p, void *data)
+static int dump_stag(unsigned long id, struct c4iw_debugfs_data *stagd)
 {
-	struct c4iw_debugfs_data *stagd = data;
 	int space;
 	int cc;
 	struct fw_ri_tpte tpte;
@@ -425,6 +424,8 @@ static int stag_release(struct inode *inode, struct file *file)
 static int stag_open(struct inode *inode, struct file *file)
 {
 	struct c4iw_debugfs_data *stagd;
+	void *p;
+	unsigned long index;
 	int ret = 0;
 	int count = 1;
 
@@ -436,9 +437,8 @@ static int stag_open(struct inode *inode, struct file *file)
 	stagd->devp = inode->i_private;
 	stagd->pos = 0;
 
-	spin_lock_irq(&stagd->devp->lock);
-	idr_for_each(&stagd->devp->mmidr, count_idrs, &count);
-	spin_unlock_irq(&stagd->devp->lock);
+	xa_for_each(&stagd->devp->mrs, index, p)
+		count++;
 
 	stagd->bufsize = count * 256;
 	stagd->buf = vmalloc(stagd->bufsize);
@@ -447,9 +447,10 @@ static int stag_open(struct inode *inode, struct file *file)
 		goto err1;
 	}
 
-	spin_lock_irq(&stagd->devp->lock);
-	idr_for_each(&stagd->devp->mmidr, dump_stag, stagd);
-	spin_unlock_irq(&stagd->devp->lock);
+	xa_lock_irq(&stagd->devp->mrs);
+	xa_for_each(&stagd->devp->mrs, index, p)
+		dump_stag(index, stagd);
+	xa_unlock_irq(&stagd->devp->mrs);
 
 	stagd->buf[stagd->pos++] = 0;
 	file->private_data = stagd;
@@ -925,8 +926,6 @@ static void c4iw_rdev_close(struct c4iw_rdev *rdev)
 void c4iw_dealloc(struct uld_ctx *ctx)
 {
 	c4iw_rdev_close(&ctx->dev->rdev);
-	WARN_ON_ONCE(!idr_is_empty(&ctx->dev->mmidr));
-	idr_destroy(&ctx->dev->mmidr);
 	wait_event(ctx->dev->wait, idr_is_empty(&ctx->dev->hwtid_idr));
 	idr_destroy(&ctx->dev->hwtid_idr);
 	idr_destroy(&ctx->dev->stid_idr);
@@ -1036,7 +1035,7 @@ static struct c4iw_dev *c4iw_alloc(const struct cxgb4_lld_info *infop)
 
 	xa_init_flags(&devp->cqs, XA_FLAGS_LOCK_IRQ);
 	xa_init_flags(&devp->qps, XA_FLAGS_LOCK_IRQ);
-	idr_init(&devp->mmidr);
+	xa_init_flags(&devp->mrs, XA_FLAGS_LOCK_IRQ);
 	idr_init(&devp->hwtid_idr);
 	idr_init(&devp->stid_idr);
 	idr_init(&devp->atid_idr);
diff --git a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
index 79ceab2fd756..f24f503971ef 100644
--- a/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
+++ b/drivers/infiniband/hw/cxgb4/iw_cxgb4.h
@@ -317,7 +317,7 @@ struct c4iw_dev {
 	u32 device_cap_flags;
 	struct xarray cqs;
 	struct xarray qps;
-	struct idr mmidr;
+	struct xarray mrs;
 	spinlock_t lock;
 	struct mutex db_mutex;
 	struct dentry *debugfs_root;
@@ -357,10 +357,6 @@ static inline struct c4iw_qp *get_qhp(struct c4iw_dev *rhp, u32 qpid)
 	return xa_load(&rhp->qps, qpid);
 }
 
-static inline struct c4iw_mr *get_mhp(struct c4iw_dev *rhp, u32 mmid)
-{
-	return idr_find(&rhp->mmidr, mmid);
-}
 
 static inline int _insert_handle(struct c4iw_dev *rhp, struct idr *idr,
 				 void *handle, u32 id, int lock)
diff --git a/drivers/infiniband/hw/cxgb4/mem.c b/drivers/infiniband/hw/cxgb4/mem.c
index 7b76e6f81aeb..8f97e4791fd0 100644
--- a/drivers/infiniband/hw/cxgb4/mem.c
+++ b/drivers/infiniband/hw/cxgb4/mem.c
@@ -395,7 +395,7 @@ static int finish_mem_reg(struct c4iw_mr *mhp, u32 stag)
 	mhp->ibmr.iova = mhp->attr.va_fbo;
 	mhp->ibmr.page_size = 1U << (mhp->attr.page_size + 12);
 	pr_debug("mmid 0x%x mhp %p\n", mmid, mhp);
-	return insert_handle(mhp->rhp, &mhp->rhp->mmidr, mhp, mmid);
+	return xa_insert_irq(&mhp->rhp->mrs, mmid, mhp, GFP_KERNEL);
 }
 
 static int register_mem(struct c4iw_dev *rhp, struct c4iw_pd *php,
@@ -651,7 +651,7 @@ struct ib_mw *c4iw_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)) {
 		ret = -ENOMEM;
 		goto dealloc_win;
 	}
@@ -679,7 +679,7 @@ int c4iw_dealloc_mw(struct ib_mw *mw)
 	mhp = to_c4iw_mw(mw);
 	rhp = mhp->rhp;
 	mmid = (mw->rkey) >> 8;
-	remove_handle(rhp, &rhp->mmidr, mmid);
+	xa_erase_irq(&rhp->mrs, mmid);
 	deallocate_window(&rhp->rdev, mhp->attr.stag, mhp->dereg_skb,
 			  mhp->wr_waitp);
 	kfree_skb(mhp->dereg_skb);
@@ -746,7 +746,7 @@ struct ib_mr *c4iw_alloc_mr(struct ib_pd *pd,
 	mhp->attr.state = 0;
 	mmid = (stag) >> 8;
 	mhp->ibmr.rkey = mhp->ibmr.lkey = stag;
-	if (insert_handle(rhp, &rhp->mmidr, mhp, mmid)) {
+	if (xa_insert_irq(&rhp->mrs, mmid, mhp, GFP_KERNEL)) {
 		ret = -ENOMEM;
 		goto err_dereg;
 	}
@@ -803,7 +803,7 @@ int c4iw_dereg_mr(struct ib_mr *ib_mr)
 	mhp = to_c4iw_mr(ib_mr);
 	rhp = mhp->rhp;
 	mmid = mhp->attr.stag >> 8;
-	remove_handle(rhp, &rhp->mmidr, mmid);
+	xa_erase_irq(&rhp->mrs, mmid);
 	if (mhp->mpl)
 		dma_free_coherent(&mhp->rhp->rdev.lldi.pdev->dev,
 				  mhp->max_mpl_len, mhp->mpl, mhp->mpl_addr);
@@ -827,9 +827,9 @@ void c4iw_invalidate_mr(struct c4iw_dev *rhp, u32 rkey)
 	struct c4iw_mr *mhp;
 	unsigned long flags;
 
-	spin_lock_irqsave(&rhp->lock, flags);
-	mhp = get_mhp(rhp, rkey >> 8);
+	xa_lock_irqsave(&rhp->mrs, flags);
+	mhp = xa_load(&rhp->mrs, rkey >> 8);
 	if (mhp)
 		mhp->attr.state = 0;
-	spin_unlock_irqrestore(&rhp->lock, flags);
+	xa_unlock_irqrestore(&rhp->mrs, flags);
 }
