// SPDX-License-Identifier: GPL-2.0-or-later/* * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved. */ #include <linux/kernel.h>#include <linux/spinlock.h>#include <linux/device.h>#include <linux/idr.h>#include <linux/kdev_t.h>#include <linux/err.h>#include <linux/dca.h>#include <linux/gfp.h>#include <linux/export.h> static const struct class dca_class = {	.name = "dca",};static struct idr dca_idr;static spinlock_t dca_idr_lock; int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot){	struct device *cd;	static int req_count; 	cd = device_create(&dca_class, dca->cd, MKDEV(0, slot + 1), NULL,			   "requester%d", req_count++);	return PTR_ERR_OR_ZERO(cd);} void dca_sysfs_remove_req(struct dca_provider *dca, int slot){	device_destroy(&dca_class, MKDEV(0, slot + 1));} int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev){	struct device *cd;	int ret; 	idr_preload(GFP_KERNEL);	spin_lock(&dca_idr_lock); 	ret = idr_alloc(&dca_idr, dca, 0, 0, GFP_NOWAIT);	if (ret >= 0)		dca->id = ret; 	spin_unlock(&dca_idr_lock);	idr_preload_end();	if (ret < 0)		return ret; 	cd = device_create(&dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);	if (IS_ERR(cd)) {		spin_lock(&dca_idr_lock);		idr_remove(&dca_idr, dca->id);		spin_unlock(&dca_idr_lock);		return PTR_ERR(cd);	}	dca->cd = cd;	return 0;} void dca_sysfs_remove_provider(struct dca_provider *dca){	device_unregister(dca->cd);	dca->cd = NULL;	spin_lock(&dca_idr_lock);	idr_remove(&dca_idr, dca->id);	spin_unlock(&dca_idr_lock);} int __init dca_sysfs_init(void){	int err; 	idr_init(&dca_idr);	spin_lock_init(&dca_idr_lock); 	err = class_register(&dca_class);	if (err) {		idr_destroy(&dca_idr);		return err;	}	return 0;} void __exit dca_sysfs_exit(void){	class_unregister(&dca_class);	idr_destroy(&dca_idr);}