Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#include <linux/kernel.h>
2#include <linux/spinlock.h>
3#include <linux/device.h>
4#include <linux/idr.h>
5#include <linux/kdev_t.h>
6#include <linux/err.h>
7#include <linux/dca.h>
8
9static struct class *dca_class;
10static struct idr dca_idr;
11static spinlock_t dca_idr_lock;
12
13int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
14{
15 struct device *cd;
16 static int req_count;
17
18 cd = device_create_drvdata(dca_class, dca->cd,
19 MKDEV(0, slot + 1), NULL,
20 "requester%d", req_count++);
21 if (IS_ERR(cd))
22 return PTR_ERR(cd);
23 return 0;
24}
25
26void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
27{
28 device_destroy(dca_class, MKDEV(0, slot + 1));
29}
30
31int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
32{
33 struct device *cd;
34 int err = 0;
35
36idr_try_again:
37 if (!idr_pre_get(&dca_idr, GFP_KERNEL))
38 return -ENOMEM;
39 spin_lock(&dca_idr_lock);
40 err = idr_get_new(&dca_idr, dca, &dca->id);
41 spin_unlock(&dca_idr_lock);
42 switch (err) {
43 case 0:
44 break;
45 case -EAGAIN:
46 goto idr_try_again;
47 default:
48 return err;
49 }
50
51 cd = device_create_drvdata(dca_class, dev, MKDEV(0, 0), NULL,
52 "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
63void 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
72int __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
85void __exit dca_sysfs_exit(void)
86{
87 class_destroy(dca_class);
88 idr_destroy(&dca_idr);
89}
90