1 /*
2  * Copyright 2014 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  * Authors: Ben Skeggs <bskeggs@redhat.com>
23  */
24 #include <core/notify.h>
25 #include <core/event.h>
26 
27 static inline void
nvkm_notify_put_locked(struct nvkm_notify * notify)28 nvkm_notify_put_locked(struct nvkm_notify *notify)
29 {
30 	if (notify->block++ == 0)
31 		nvkm_event_put(notify->event, notify->types, notify->index);
32 }
33 
34 void
nvkm_notify_put(struct nvkm_notify * notify)35 nvkm_notify_put(struct nvkm_notify *notify)
36 {
37 	struct nvkm_event *event = notify->event;
38 	unsigned long flags;
39 	if (likely(event) &&
40 	    test_and_clear_bit(NVKM_NOTIFY_USER, &notify->flags)) {
41 		spin_lock_irqsave(&event->refs_lock, flags);
42 		nvkm_notify_put_locked(notify);
43 		spin_unlock_irqrestore(&event->refs_lock, flags);
44 		if (test_bit(NVKM_NOTIFY_WORK, &notify->flags))
45 			flush_work(&notify->work);
46 	}
47 }
48 
49 static inline void
nvkm_notify_get_locked(struct nvkm_notify * notify)50 nvkm_notify_get_locked(struct nvkm_notify *notify)
51 {
52 	if (--notify->block == 0)
53 		nvkm_event_get(notify->event, notify->types, notify->index);
54 }
55 
56 void
nvkm_notify_get(struct nvkm_notify * notify)57 nvkm_notify_get(struct nvkm_notify *notify)
58 {
59 	struct nvkm_event *event = notify->event;
60 	unsigned long flags;
61 	if (likely(event) &&
62 	    !test_and_set_bit(NVKM_NOTIFY_USER, &notify->flags)) {
63 		spin_lock_irqsave(&event->refs_lock, flags);
64 		nvkm_notify_get_locked(notify);
65 		spin_unlock_irqrestore(&event->refs_lock, flags);
66 	}
67 }
68 
69 static inline void
nvkm_notify_func(struct nvkm_notify * notify)70 nvkm_notify_func(struct nvkm_notify *notify)
71 {
72 	struct nvkm_event *event = notify->event;
73 	int ret = notify->func(notify);
74 	unsigned long flags;
75 	if ((ret == NVKM_NOTIFY_KEEP) ||
76 	    !test_and_clear_bit(NVKM_NOTIFY_USER, &notify->flags)) {
77 		spin_lock_irqsave(&event->refs_lock, flags);
78 		nvkm_notify_get_locked(notify);
79 		spin_unlock_irqrestore(&event->refs_lock, flags);
80 	}
81 }
82 
83 static void
nvkm_notify_work(struct work_struct * work)84 nvkm_notify_work(struct work_struct *work)
85 {
86 	struct nvkm_notify *notify = container_of(work, typeof(*notify), work);
87 	nvkm_notify_func(notify);
88 }
89 
90 void
nvkm_notify_send(struct nvkm_notify * notify,void * data,u32 size)91 nvkm_notify_send(struct nvkm_notify *notify, void *data, u32 size)
92 {
93 	struct nvkm_event *event = notify->event;
94 	unsigned long flags;
95 
96 	assert_spin_locked(&event->list_lock);
97 	BUG_ON(size != notify->size);
98 
99 	spin_lock_irqsave(&event->refs_lock, flags);
100 	if (notify->block) {
101 		spin_unlock_irqrestore(&event->refs_lock, flags);
102 		return;
103 	}
104 	nvkm_notify_put_locked(notify);
105 	spin_unlock_irqrestore(&event->refs_lock, flags);
106 
107 	if (test_bit(NVKM_NOTIFY_WORK, &notify->flags)) {
108 		memcpy((void *)notify->data, data, size);
109 		schedule_work(&notify->work);
110 	} else {
111 		notify->data = data;
112 		nvkm_notify_func(notify);
113 		notify->data = NULL;
114 	}
115 }
116 
117 void
nvkm_notify_fini(struct nvkm_notify * notify)118 nvkm_notify_fini(struct nvkm_notify *notify)
119 {
120 	unsigned long flags;
121 	if (notify->event) {
122 		nvkm_notify_put(notify);
123 		spin_lock_irqsave(&notify->event->list_lock, flags);
124 		list_del(&notify->head);
125 		spin_unlock_irqrestore(&notify->event->list_lock, flags);
126 		kfree((void *)notify->data);
127 		notify->event = NULL;
128 	}
129 }
130 
131 int
nvkm_notify_init(struct nvkm_object * object,struct nvkm_event * event,int (* func)(struct nvkm_notify *),bool work,void * data,u32 size,u32 reply,struct nvkm_notify * notify)132 nvkm_notify_init(struct nvkm_object *object, struct nvkm_event *event,
133 		 int (*func)(struct nvkm_notify *), bool work,
134 		 void *data, u32 size, u32 reply,
135 		 struct nvkm_notify *notify)
136 {
137 	unsigned long flags;
138 	int ret = -ENODEV;
139 	if ((notify->event = event), event->refs) {
140 		ret = event->func->ctor(object, data, size, notify);
141 		if (ret == 0 && (ret = -EINVAL, notify->size == reply)) {
142 			notify->flags = 0;
143 			notify->block = 1;
144 			notify->func = func;
145 			notify->data = NULL;
146 			if (ret = 0, work) {
147 				INIT_WORK(&notify->work, nvkm_notify_work);
148 				set_bit(NVKM_NOTIFY_WORK, &notify->flags);
149 				notify->data = kmalloc(reply, GFP_KERNEL);
150 				if (!notify->data)
151 					ret = -ENOMEM;
152 			}
153 		}
154 		if (ret == 0) {
155 			spin_lock_irqsave(&event->list_lock, flags);
156 			list_add_tail(&notify->head, &event->list);
157 			spin_unlock_irqrestore(&event->list_lock, flags);
158 		}
159 	}
160 	if (ret)
161 		notify->event = NULL;
162 	return ret;
163 }
164