/**
 * ida_free() - Release an allocated ID.
 * @ida: IDA handle.
 * @id: Previously allocated ID.
 *
 * Context: Any context.
 */
void ida_free(struct ida *ida, unsigned int id)
{
        unsigned long flags;

        BUG_ON((int)id < 0);
        xa_lock_irqsave(&ida->ida_rt, flags);
        ida_remove(ida, id);
        xa_unlock_irqrestore(&ida->ida_rt, flags);
}
EXPORT_SYMBOL(ida_free);

/*
 * IDA.
 *
 * (C) 2019.06.04 <buddy.zhang@aliyun.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>

/* header of IDA/IDR */
#include <linux/idr.h>
#include <linux/radix-tree.h>

/* Root of IDA */
static DEFINE_IDA(BiscuitOS_ida);

static __init int ida_demo_init(void)
{
	int id;

	/* Allocate an unused ID */
	id = ida_alloc_range(&BiscuitOS_ida, 0x10, INT_MAX,  GFP_KERNEL);
	printk("IDA-ID: %#x\n", id);

	/* Release an ID */
	ida_free(&BiscuitOS_ida, id);

	return 0;
}
device_initcall(ida_demo_init);

diff --git a/drivers/BiscuitOS/Kconfig b/drivers/BiscuitOS/Kconfig
index 4edc5a5..1a9abee 100644
--- a/drivers/BiscuitOS/Kconfig
+++ b/drivers/BiscuitOS/Kconfig
@@ -6,4 +6,14 @@ if BISCUITOS_DRV
config BISCUITOS_MISC
        bool "BiscuitOS misc driver"
+config BISCUITOS_IDA
+       bool "IDA"
+
+if BISCUITOS_IDA
+
+config DEBUG_BISCUITOS_IDA
+       bool "ida_free"
+
+endif # BISCUITOS_IDA
+
endif # BISCUITOS_DRV

diff --git a/drivers/BiscuitOS/Makefile b/drivers/BiscuitOS/Makefile
index 82004c9..9909149 100644
--- a/drivers/BiscuitOS/Makefile
+++ b/drivers/BiscuitOS/Makefile
@@ -1 +1,2 @@
obj-$(CONFIG_BISCUITOS_MISC)     += BiscuitOS_drv.o
+obj-$(CONFIG_BISCUITOS_IDA)     += ida.o
--

Device Driver--->
    [*]BiscuitOS Driver--->
        [*]IDA
            [*]ida_free()

usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
IDA-ID: 0x10
aaci-pl041 10004000.aaci: ARM AC'97 Interface PL041 rev0 at 0x10004000, irq 24
aaci-pl041 10004000.aaci: FIFO 512 entries
oprofile: using arm/armv7-ca9