1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/spinlock.h>
8 #include <linux/device.h>
9 #include <linux/idr.h>
10 #include <linux/kdev_t.h>
11 #include <linux/err.h>
12 #include <linux/dca.h>
13 #include <linux/gfp.h>
14 #include <linux/export.h>
15 
16 static struct class *dca_class;
17 static struct idr dca_idr;
18 static spinlock_t dca_idr_lock;
19 
dca_sysfs_add_req(struct dca_provider * dca,struct device * dev,int slot)20 int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
21 {
22 	struct device *cd;
23 	static int req_count;
24 
25 	cd = device_create(dca_class, dca->cd, MKDEV(0, slot + 1), NULL,
26 			   "requester%d", req_count++);
27 	return PTR_ERR_OR_ZERO(cd);
28 }
29 
dca_sysfs_remove_req(struct dca_provider * dca,int slot)30 void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
31 {
32 	device_destroy(dca_class, MKDEV(0, slot + 1));
33 }
34 
dca_sysfs_add_provider(struct dca_provider * dca,struct device * dev)35 int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
36 {
37 	struct device *cd;
38 	int ret;
39 
40 	idr_preload(GFP_KERNEL);
41 	spin_lock(&dca_idr_lock);
42 
43 	ret = idr_alloc(&dca_idr, dca, 0, 0, GFP_NOWAIT);
44 	if (ret >= 0)
45 		dca->id = ret;
46 
47 	spin_unlock(&dca_idr_lock);
48 	idr_preload_end();
49 	if (ret < 0)
50 		return ret;
51 
52 	cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);
53 	if (IS_ERR(cd)) {
54 		spin_lock(&dca_idr_lock);
55 		idr_remove(&dca_idr, dca->id);
56 		spin_unlock(&dca_idr_lock);
57 		return PTR_ERR(cd);
58 	}
59 	dca->cd = cd;
60 	return 0;
61 }
62 
dca_sysfs_remove_provider(struct dca_provider * dca)63 void dca_sysfs_remove_provider(struct dca_provider *dca)
64 {
65 	device_unregister(dca->cd);
66 	dca->cd = NULL;
67 	spin_lock(&dca_idr_lock);
68 	idr_remove(&dca_idr, dca->id);
69 	spin_unlock(&dca_idr_lock);
70 }
71 
dca_sysfs_init(void)72 int __init dca_sysfs_init(void)
73 {
74 	idr_init(&dca_idr);
75 	spin_lock_init(&dca_idr_lock);
76 
77 	dca_class = class_create(THIS_MODULE, "dca");
78 	if (IS_ERR(dca_class)) {
79 		idr_destroy(&dca_idr);
80 		return PTR_ERR(dca_class);
81 	}
82 	return 0;
83 }
84 
dca_sysfs_exit(void)85 void __exit dca_sysfs_exit(void)
86 {
87 	class_destroy(dca_class);
88 	idr_destroy(&dca_idr);
89 }
90 
91