xref: /linux/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chid.c (revision 69bfec7548f4c1595bac0e3ddfc0458a5af31f4c)
1 /*
2  * Copyright 2020 Red Hat Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  */
22 #include "chid.h"
23 
24 void
25 nvkm_chid_put(struct nvkm_chid *chid, int id, spinlock_t *data_lock)
26 {
27 	if (id >= 0) {
28 		spin_lock_irq(&chid->lock);
29 		spin_lock(data_lock);
30 		chid->data[id] = NULL;
31 		spin_unlock(data_lock);
32 		clear_bit(id, chid->used);
33 		spin_unlock_irq(&chid->lock);
34 	}
35 }
36 
37 int
38 nvkm_chid_get(struct nvkm_chid *chid, void *data)
39 {
40 	int id = -1, cid;
41 
42 	spin_lock_irq(&chid->lock);
43 	cid = find_first_zero_bit(chid->used, chid->nr);
44 	if (cid < chid->nr) {
45 		set_bit(cid, chid->used);
46 		chid->data[cid] = data;
47 		id = cid;
48 	}
49 	spin_unlock_irq(&chid->lock);
50 	return id;
51 }
52 
53 static void
54 nvkm_chid_del(struct kref *kref)
55 {
56 	struct nvkm_chid *chid = container_of(kref, typeof(*chid), kref);
57 
58 	nvkm_event_fini(&chid->event);
59 
60 	kvfree(chid->data);
61 	kfree(chid);
62 }
63 
64 void
65 nvkm_chid_unref(struct nvkm_chid **pchid)
66 {
67 	struct nvkm_chid *chid = *pchid;
68 
69 	if (!chid)
70 		return;
71 
72 	kref_put(&chid->kref, nvkm_chid_del);
73 	*pchid = NULL;
74 }
75 
76 struct nvkm_chid *
77 nvkm_chid_ref(struct nvkm_chid *chid)
78 {
79 	if (chid)
80 		kref_get(&chid->kref);
81 
82 	return chid;
83 }
84 
85 int
86 nvkm_chid_new(const struct nvkm_event_func *func, struct nvkm_subdev *subdev,
87 	      int nr, int first, int count, struct nvkm_chid **pchid)
88 {
89 	struct nvkm_chid *chid;
90 	int id;
91 
92 	if (!(chid = *pchid = kzalloc(struct_size(chid, used, nr), GFP_KERNEL)))
93 		return -ENOMEM;
94 
95 	kref_init(&chid->kref);
96 	chid->nr = nr;
97 	chid->mask = chid->nr - 1;
98 	spin_lock_init(&chid->lock);
99 
100 	if (!(chid->data = kvzalloc(sizeof(*chid->data) * nr, GFP_KERNEL))) {
101 		nvkm_chid_unref(pchid);
102 		return -ENOMEM;
103 	}
104 
105 	for (id = 0; id < first; id++)
106 		__set_bit(id, chid->used);
107 	for (id = first + count; id < nr; id++)
108 		__set_bit(id, chid->used);
109 
110 	return nvkm_event_init(func, subdev, 1, nr, &chid->event);
111 }
112