From e2b63f79b8f3d88e281a25f71b831cc9e85e0377 Mon Sep 17 00:00:00 2001
From: Matthew Wilcox <willy@infradead.org>
Date: Mon, 18 Feb 2019 09:49:21 -0500
Subject: [PATCH] ac97: Convert ac97_adapter_idr to XArray

Signed-off-by: Matthew Wilcox <willy@infradead.org>
---
 include/sound/ac97/controller.h |  2 --
 sound/ac97/bus.c                | 16 ++++++----------
 2 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/include/sound/ac97/controller.h b/include/sound/ac97/controller.h
index 06b5afb7fa6b..64d8bdf68790 100644
--- a/include/sound/ac97/controller.h
+++ b/include/sound/ac97/controller.h
@@ -17,7 +17,6 @@ struct ac97_controller_ops;
 /**
  * struct ac97_controller - The AC97 controller of the AC-Link
  * @ops:		the AC97 operations.
- * @controllers:	linked list of all existing controllers.
  * @adap:		the shell device ac97-%d, ie. ac97 adapter
  * @nr:			the number of the shell device
  * @slots_available:	the mask of accessible/scanable codecs.
@@ -30,7 +29,6 @@ struct ac97_controller_ops;
  */
 struct ac97_controller {
 	const struct ac97_controller_ops *ops;
-	struct list_head controllers;
 	struct device adap;
 	int nr;
 	unsigned short slots_available;
diff --git a/sound/ac97/bus.c b/sound/ac97/bus.c
index 7985dd8198b6..fae3668f4401 100644
--- a/sound/ac97/bus.c
+++ b/sound/ac97/bus.c
@@ -7,7 +7,6 @@
 #include <linux/bitops.h>
 #include <linux/clk.h>
 #include <linux/device.h>
-#include <linux/idr.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
@@ -15,6 +14,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
+#include <linux/xarray.h>
 #include <sound/ac97/codec.h>
 #include <sound/ac97/controller.h>
 #include <sound/ac97/regs.h>
@@ -22,11 +22,10 @@
 #include "ac97_core.h"
 
 /*
- * Protects ac97_controllers and each ac97_controller structure.
+ * Protects each ac97_controller structure.
  */
 static DEFINE_MUTEX(ac97_controllers_mutex);
-static DEFINE_IDR(ac97_adapter_idr);
-static LIST_HEAD(ac97_controllers);
+static DEFINE_XARRAY_ALLOC(ac97_adapters);
 
 static struct bus_type ac97_bus_type;
 
@@ -287,7 +286,6 @@ static void ac97_del_adapter(struct ac97_controller *ac97_ctrl)
 {
 	mutex_lock(&ac97_controllers_mutex);
 	ac97_ctrl_codecs_unregister(ac97_ctrl);
-	list_del(&ac97_ctrl->controllers);
 	mutex_unlock(&ac97_controllers_mutex);
 
 	device_unregister(&ac97_ctrl->adap);
@@ -298,7 +296,7 @@ static void ac97_adapter_release(struct device *dev)
 	struct ac97_controller *ac97_ctrl;
 
 	ac97_ctrl = to_ac97_controller(dev);
-	idr_remove(&ac97_adapter_idr, ac97_ctrl->nr);
+	xa_erase(&ac97_adapters, ac97_ctrl->nr);
 	dev_dbg(&ac97_ctrl->adap, "adapter unregistered by %s\n",
 		dev_name(ac97_ctrl->parent));
 }
@@ -313,8 +311,8 @@ static int ac97_add_adapter(struct ac97_controller *ac97_ctrl)
 	int ret;
 
 	mutex_lock(&ac97_controllers_mutex);
-	ret = idr_alloc(&ac97_adapter_idr, ac97_ctrl, 0, 0, GFP_KERNEL);
-	ac97_ctrl->nr = ret;
+	ret = xa_alloc(&ac97_adapters, &ac97_ctrl->nr, ac97_ctrl,
+			xa_limit_32b, GFP_KERNEL);
 	if (ret >= 0) {
 		dev_set_name(&ac97_ctrl->adap, "ac97-%d", ret);
 		ac97_ctrl->adap.type = &ac97_adapter_type;
@@ -323,8 +321,6 @@ static int ac97_add_adapter(struct ac97_controller *ac97_ctrl)
 		if (ret)
 			put_device(&ac97_ctrl->adap);
 	}
-	if (!ret)
-		list_add(&ac97_ctrl->controllers, &ac97_controllers);
 	mutex_unlock(&ac97_controllers_mutex);
 
 	if (!ret)
-- 
2.50.1